Title of Invention	A CONTINUOUSLY VARIABLE TRANSMISSION METHOD AND SYSTEM
Abstract	[Object] To allow fuel economy, quietness, and drivability to coexist in a plurality of vehicle driving modes, and to improve drivability by preventing a kick-down amount from becoming excessive at a time of sudden opening of a throttle. [Solving Means] In a system having a transmission control ECU (17) and an engine control ECU (42) as separate bodies, a transmission characteristic is selected by switching a transmission map (45) of the transmission control ECU (17) depending on a driving mode. The transmission map (45) outputs a target engine revolution number in order to control the transmission ratio of acontinuously variable transmission (1). A motor driver (46) changes the transmission ratio by driving a motor (7) on the bases of the target engine revolution number and an actual revolution number. In response to the switching of the transmission map, a map is selected from each of a group of ignition timing maps (48) and a group of fuel injection time maps (49) in the engine control ECU (42).

Title of Invention

A CONTINUOUSLY VARIABLE TRANSMISSION METHOD AND SYSTEM

Abstract

[Object] To allow fuel economy, quietness, and drivability to coexist in a plurality of vehicle driving modes, and to improve drivability by preventing a kick-down amount from becoming excessive at a time of sudden opening of a throttle. [Solving Means] In a system having a transmission control ECU (17) and an engine control ECU (42) as separate bodies, a transmission characteristic is selected by switching a transmission map (45) of the transmission control ECU (17) depending on a driving mode. The transmission map (45) outputs a target engine revolution number in order to control the transmission ratio of acontinuously variable transmission (1). A motor driver (46) changes the transmission ratio by driving a motor (7) on the bases of the target engine revolution number and an actual revolution number. In response to the switching of the transmission map, a map is selected from each of a group of ignition timing maps (48) and a group of fuel injection time maps (49) in the engine control ECU (42).

Full Text	[Document Name] Specification [Title of the Invention] VEHICLE CONTROL SYSTEM, CONTINUOUSLY VARIABLE TRANSMISSION CONTROL SYSTEM AND METHOD [Technical Field of the Invention] The present invention relates to a vehicle control system, a continuously variable transmission control system and a method. In particular, the present invention relates to a vehicle control system in which an engine control ECU for controlling fuel injection and ignition and a power train control ECU for controlling a transmission are caused to operate in cooperation, and a continuously variable transmission system and a method which are suitable for changing transmission characteristics in accordance with a throttle opening degree variation to obtain smooth acceleration performance (drivability). [Background Art] A cooperative control system in which an engine and a transmission operate in cooperation is known to reduce shocks to a vehicle which are caused by activation of variable mechanisms of the engine, such as an intake switch valve and a torque converter, and by the activation of the transmission (see Japanese Unexamined Patent Publication No. 2001-39183). The states of the variable mechanisms during the gearshift, such as an early, intermediate, or later phase of a gearshift, are controlledbased on the kind of the gearshift. On the other hand, Japanese Unexamined Patent Publication No. 2003-239774 discloses an engine control system which makes it possible to ensure a driving force and drivability of a vehicle by controlling activation characteristics of intake valves and exhaust valves when transmission control comes not to be normally executed. Japanese Patent Application publication No. Hei7-239016 discloses a transmission control system which is configured in a configuration for shifting transmission patterns in accordance with a driving state of a vehicle in order that, when a vehicle in a specific driving state, such as driving in heavy traffic or in a residential area, has exited this specific driving state, if there is no change between transmission stages before and after the specific driving state, a judgment that the vehicle has come out of the specific driving state can be delayed. This control makes it possible to promote suppression of transmission shock by avoiding frequent changes in driving state judgment parameters, the changes being attributable to an unintentional accelerator operation, noises and the like. Additionally, there has been known a control system which, in a belt-type continuously variable transmission coupled to an internal combustion engine (hereinafter, referred to as an "engine"), controls a pulley ratio by allowing a movable half of a drive pulley to slide in a direction of an output shaft of the engine (Japanese Patent Application publication No. Hei6-123321). In this control system, a target ratio is determined by performing a map search based on a throttle opening degree and a vehicle speed, and a motor is driven in order that this target ratio can be obtained. Furthermore, a duty ratio of the motor is increased according to a magnitude of a difference between the target ratio and an actual pulley ratio, and a duty is controlled in accordance with ON and OFF states of an accelerator. By this control, smooth actions, which arematched with transmission requirements according to driving situations, of the transmission are expected. [Patent Document 1] Japanese Unexamined Patent Publication No. 2001-39183 [Patent Document 2 ] Japanese Unexamined Patent Publication No. 2003-239774 [Patent Document 3] Japanese Patent Application publication No. Hei7-239016 [ Patent Document 4 ] Japanese Patent Application publication No. Hei6-123351 [Disclosure of the Invention] [Problems to be Solved by the Invention] In the control systems described in Patent Documents 1 and 2, transmission control and engine control are made to have a certain relationship, but fuel injection control and ignition control are not performed in relation to the shift mode of a transmission. For example, it is possible to conceive of a two-wheeled motor vehicle in which selection of one from a manual shift mode and a plurality of automatic shift modes makes driving possible. An engine control system mounted on such a vehicle is desired to be capable of operating in relation to a transmission control system for each shift mode from the viewpoint of improvement of fuel economy, quietness, and the like, for each shift mode. One object of the present invention is to provide a vehicle control system in which a power train control ECU and an engine control ECU are separate bodies and in which optimum fuel injection and ignition can be performed depending on a shift mode. In the continuously variable transmission control system in Patent Document 4, a target engine revolution number is obtained by performing a map search based on a throttle opening degree and a vehicle speed, and a pulley ratio, i.e., a transmission ratio is controlled in order that the target engine revolution number can be reached. In this case, the target engine revolution number is uniquely determined with the throttle opening degree. Accordingly, for example, when an operation of suddenly opening a throttle valve is made under a transmission characteristic suitable for normal driving, there is a possibility of fail ing to obtain an appropriate kick-down amount. Therefore, there is a possibility that drivability may be reduced because driving states cannot be changed smoothly. Another object of the present invention is to provide a continuously variable transmission control system, and a method, which are capable of obtaining an appropriate variation in transmission ratio regardless of opening or closing speed of a throttle valve. [Means for Solving the Problems] The present invention for achieving the objects mentioned above has a first characteristic in a configuration of a vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, wherein a control map corresponding to a driving mode information set up in the power train control ECU is selected from control maps provided in the engine control to correspond to a plurality of driving modes, the engine control ECU being controlled according to control information found from the selected control map. Moreover, the present invention has a second characteristic in the vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: a plurality of control parameter output means applicable respectively to a plurality of vehicle driving modes; and means for selecting one control parameter output means both from the plurality of control parameter output means provided in the engine control ECU and one from the plurality of control parameter output means provided in the power train control ECU according to the vehicle driving mode selected. Furthermore, the present invention has a third characteristic in a vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: an actuator for adjusting a transmission ratio of the continuously variable transmission; and a mode switch for selecting a driving mode of a vehicle, the power train ECU comprising: target engine revolution number output means for outputting an engine revolution number corresponding to the driving mode; and a driver for supplying the actuator with a drive instruction to converge an actual revolution number of the engine on the target engine revolution number, the engine control ECU comprising: a plurality of ignition timing output means for outputting ignition timing depending on the driving mode of the vehicle; a plurality of injection time output means for outputting a fuel injection time depending on the driving mode of the vehicle; an ignition driver for supplying a drive signal to an ignition plug according to the ignition timing; and an injection valve driver for supplying a drive signal to a fuel injection valve according to the fuel injection time. Besides, the present invention for achieving the objects mentioned above is characterized by a method of a continuously variable transmission control with which the target engine revolution number of the continuously variable transmission control system installed in a vehicle is decided depending on the throttle opening degree and the vehicle speed, the method comprising the steps of: setting the target engine revolution number larger as the throttle opening degree is larger; and adding, if a variation of the throttle opening degree with respect to each of predetermined process cycles is larger than a threshold value according to the vehicle speed, a first value to a throttle opening degree which determines the target engine revolution number, and adding, if the variation of the throttle opening degree is smaller than the threshold value, a second value larger than the first value to the throttle opening degree which determines the target engine revolution number. [Effect of the Invention] According to the present invention having the aforementioned first characteristic, when a driving mode is set up in the engine drive control ECU, the control map corresponding to the driving mode is selected among the control maps provided in the engine control ECU and used to control the engine control ECU. Further, according to the second and third characteristics, the control parameter output means corresponding to the driving mode is selected from the plurality of control parameter output means provided in each of the engine control ECU and the power train control ECU. Thus, the engine control ECU and the power train control ECU are controlled on the bases of the driving mode to operate in cooperation. Accordingly, engine control including appropriate fuel injection and ignition timing depending on the shift mode of a continuously variable transmission isperformed, andperformance, such as fuel economy, quietness, and drivability, which is in response to the driving mode, can be obtained. According to the present invention characterized as above, the throttle opening degree used for determining the target engine revolution number is corrected on the bases of whether a throttle opening degree variation in predetermined unit time is larger than a threshold value preset in accordance with a vehicle speed. That is, if the throttle opening degree variation in predetermined unit time is larger than the threshold value, a small value is added to the throttle opening degree used for determining the target engine revolution number. On the other hand, if the throttle opening degree variation per predetermined unit time is smaller than the threshold value, a large value is added to the throttle opening degree used for determining the target engine revolution number. Thus, when a throttle is suddenly opened, the throttle opening degree used for determining the target engine revolution number is made smaller than it is when the throttle is in normal operation. Accordingly, even when the throttle is suddenly opened, a sudden increase in engine revolution number is avoided, whereby there is no possibility that a kick-down amount may become too large. [Best Modes for Carrying out the Invention] Hereinafter, one embodiment of the present invention will be described by referring to the drawings. FIG. 2 is a system configuration diagram of a continuously variable transmission control system according to the one embodiment of the present invention. A continuously variable transmission 1 is coupled to a crankshaft, i.e., an output shaft 2 of an engine (not illustrated) which is a drive source of, for example, a scooter. A drive pulley 3 is composed of: a fixed pulley half 31; and a movable pulley half 32 provided to the output shaft 2 so as to be freely slidable in an axial direction of the output shaft 2. To an outer periphery of a hub of the movable pulley half 32, a slider 5 is supported through a bearing 4. A gear 51 is formed on the periphery of the slider 5. The gear 51 engages with a final-stage gear 64 of a decelerator 6 composed of four gears 61, 62, 63 and 64, and the first-stage gear 61 of the decelerator 6 engages with an output gear 71 of the motor 7. A male screw formed on an outer periphery of a cylinder 9 fixed to a case 8 is screwed into a female screw formed on an inner periphery of the slider 5. When the slider 5 is rotated by revolution of the motor 7, the female screw on the slider 5 rotates around the male screw on the cylinder 9, and a feeding action in an axial direction of the screw allows the slider 5 to move in the axial direction of the output shaft 2 . This move of the slider 5 changes a distance between the fixed pulley half 31 and the movable pulley half 32 of the drive pulley 3. A driven pulley 10 of the continuously variable transmission 1 is supported by a driven shaft 11. The driven pulley 10 is composed of a movable pulley half 101 and a fixed pulley half 102, which are both freely rotatable with respect to the driven shaft 11. Furthermore, the movable pulley half 101 is also freely slidable with respect to the driven shaft 11 in an axial direction thereof, and is energized toward the fixed pulley half 102 by a coil spring 103. A centrifugal clutch 12 is provided to the driven shaft 11, and the movable pulley half 101 is coupled with the driven shaft 11 through the centrifugal clutch 12. A V-belt 14 is hung on the drive pulley 3 and the driven pulley 10. A position sensor 15 for detecting a reset position of the movable pulley half 32 of the drive pulley 3 is provided so as to be close to the outer periphery of the movable pulley half 32 . Additionally, a driven pulley revolution number sensor 16 for detecting a revolution number of a driven shaft 11 is arranged so as to face a magnetic substance (not illustrated) which rotates with the driven pulley 10. As a control system for the continuously variable transmission 1, a transmission control ECU 17 for driving the motor 7 is provided. The transmission control ECU 17 includes a microcomputer, and receives power supply from a buttery 18. In the scooter, a mode switch 19 used for selecting a driving mode is provided- In accordance with a driving mode, a transmission characteristic is selected from a manual mode and a plurality of automatic modes. A change switch 20 outputs a change signal CH for shifting transmission stages in a direction toward a higher transmission stage, or in a direction toward a lower transmission stage. The change switch 20 becomes effective under the manual mode, and a transmission stage is selected in accordance with the change signal CH. Under the manual mode, the motor 7 is driven so as to set up a predetermined pulley ratio with respect to each of transmission stages. The pulley ratio is defined as an engine revolution number Nl of the driven pulley 10 in proportion to an engine revolution number NO of the drive pulley 3 (N1/N0) . A throttle sensor 21 detects an opening degree of a throttle valve of the engine not illustrated, and outputs opening degree information TH. An engine revolution number sensor 22 detects a reluctor, and outputs a revolution number of the ACG, i.e., an engine revolution number Ne, the reluctor being provided in a rotor of an AC generator (ACG) not illustrated which is coupled to the output shaft of the engine. A description will be given for driving modes. Plural driving modes are set up, and different transmission characteristics exclusively correspond to the respective driving modes. In this embodiment, the manual mode, and, as two automatic modes, a sport driving mode and a low fuel consumption driving mode are set up. One example of the transmission characteristics of the low fuel consumption driving mode is shown in FIG. 10, and one example of the transmission characteristics of the sport driving mode is shown in FIG. 11. A plurality of transmission ratios are set up in the manual mode. There, a setup is such that any one of this plurality of transmission ratios maybe designated by use of a change switch 18, and that driving with a transmission ratio which is fixed to this designated ratio is made possible. In the sport driving mode, powerful driving is made possible with an engine revolution number relatively being high as compared with a normal driving mode, and in the low fuel consumption driving mode, contrary to the sport driving mode, a setup is such that driving with the engine revolution number being low as compared with the normal driving mode is realized. FIG. 1 is a block diagram showing functions of important units of the transmission control system (the ECU17). Based on the throttle opening degree TH and a vehicle speed V, a target engine revolution number calculating unit 73 calculates a target engine revolution number Netgt. For example, the target engine revolution number calculating unit 73 can be constituted of maps each of which outputs the target engine revolution number Netgt as a function value defined by the throttle opening degree TH and the vehicle speed V. This map is provided with respect to each of the driving modes . The vehicle speed V can be represented by a revolution number of the driven pulley 10, which is detected by the driven pulley revolution number sensor 16. FIG. 9 is a chart showing one example of a map used for obtaining the target engine revolution number Netgt. This map is a three-dimensional map with respect to a revolution number of the driven pulley (the vehicle speed V) , the throttle opening degree TH, and the target engine revolution number Netgt. By using this map, a value in a z-axis direction at an intersection point of a value (the vehicle speed V) in an x-axis direction and a value (the throttle opening degree TH) in a y-axis direction is read out as a value indicating the target engine revolution number Netgt. In the example shown in FIG. 9, when the vehicle speed V becomes high to a certain degree, a degree of increase of the target engine revolution number Netgt becomes larger, the increase being associated with increase in the vehicle speed V. That is, where the throttle opening degree TH is relatively small, a degree of increase in the target engine revolution number Netgt becomes larger from the time where the vehicle speed V becomes VI. On the other hand, where the throttle opening degree TH is relatively large, a degree of increase in the target engine revolution number Netgt becomes larger from the time where the vehicle speed V becomes V2 (V2 As a consequence, in this example, the map is, as a whole, set up in a manner that the target engine revolution number Netgt becomes larger where the throttle opening degree TH is relatively large. A motor control value determining unit 74 is transmission characteristic determining means, and determines a rotational direction of the motor 7 and a duty, i.e. , a speed, of the motor 7 on the bases of a difference between the target engine revolution number Netgt, which is calculated by the target engine revolution number calculating unit 73, and an actual engine revolution number Ne which is obtained by the engine revolution number sensor 22. If the target engine revolution number Netgt is higher than the actual engine revolution number Ne, the motor 7 is driven in a direction of increasing a distance between the fixed pulley half 31 and the movable pulley half 32 in order to increase the pulley ratio. The motor 7 is driven pursuant to a control value, i.e., a rotational direction of the motor 7, outputted by the motor control value determining unit 74, and pursuant to the target engine revolution number Netgt, whereby the pulley ratio is altered. Furthermore, for the purpose of obtaining an appropriate kick-down amount when the throttle is suddenly opened, the throttle opening degree is corrected between the time where the throttle is suddenly opened and the time where a throttle is under normal acceleration. An output of the throttle sensor 21 is corrected by addition at an adding unit 75, For example, into memories 76 and 77 which can be configured to be FIFO, the throttle opening degrees TH are read respectively on predetermined interruption cycle bases, and are stored as a previous value and a current value. In a throttle opening degree variation judging unit 78, a difference ATH between a previous value TH-1 of the throttle opening degree and a current value THO of the throttle opening degree TH is compared with a predetermined ATH judgment value, i.e., a threshold value. The ATH judgment value is set up as a map as a function of the vehicle speed V in a ATH judgment value storing unit 79. In FIG. 3, one example of a map where a relation between the ATH judgment value and the vehicle speed V is established. A throttle opening degree additional value is selected depending on whether a change ATH of the throttle opening degree is larger or smaller than the ATH judgment value. There are provided: a first additional value storing unit 80 where a map of a throttle opening degree additional value (sudden opening time additional value) in a case where the change ATH in the throttle opening degree TH is larger than the ATH judgment value is stored; and a second additional value storing unit 81 where a map of a throttle opening degree additional value (normal condition time additional value) in a case where the change ATH of the throttle opening degree TH is smaller than the ATH judgment value is stored. FIG. 6 is a flowchart for a throttle opening degree correcting process. In Step SI, an output of the driven pulley revolution number sensor 16 is read in as the vehicle speed V. In Step S2, the ATH judgment value according to the vehicle speed is read out, for example, from the map shown in FIG. 3. In Step 53, by subtracting the throttle opening degree previous value TH-1 from the throttle opening degree current value THO, the throttle opening degree variation ATH is calculated. In Step 54, it is judged whether the throttle opening degree variation ATH is at least the ATH judgment value. If the judgment is positive in Step S4, the process is progressed to Step S5, where the throttle opening degree additional value for search in a transmission map at the time of sudden throttle opening, i.e., the sudden opening time additional value is read out from the first additional value storing unit 80, and is set as an additional value for search. If the judgment is negative in Step S4, the process is progressed to Step S6, where the throttle opening degree additional value for search in a transmission map under normal conditions, i.e., the normal condition time additional value is read out from the second additional value storing unit 81, and is set as the additional value for search. In Step S7, a value obtained by adding the additional value for search to the throttle opening degree current value THO is set as the throttle opening degree TH. The target engine revolution number Netgt is found by using this throttle opening degree TH, the motor 7 is driven so that the target engine revolution number Netgt can be obtained, and kick-down is carried out. As can be understood from FIGs. 4 and 5, the sudden opening time additional value is small as compared with the normal condition time additional value. Accordingly, in a case where the current throttle opening degree THO is the same, the throttle opening degree TH for search at the time of sudden throttle opening is recognized at the target engine revolution number calculating unit 73 as a value smaller than the throttle opening degree TH under normal acceleration. As a result, even at the time of sudden throttle opening, the target engine revolution number Netgt does not change so much from the current value, whereby a sharp kick-down can be suppressed. FIG. 7 is a diagram showing: changes in the throttle opening degree TH according to a conventional system where the throttle opening degree TH used for finding a target engine revolution number is not changed on the bases of the throttle opening degree variation ATH; and changes in a value used for finding the target engine revolution number, which are associated with changes in the throttle opening degree TH. As shown in this diagram, the throttle opening degree TH and the value used for finding the target engine revolution number are substantially equal to each other. Therefore, at the time of sudden throttle opening, the target engine revolution number Netgt also suddenly changes, and the kick-down also becomes larger than the kick-back in an appropriate state in view of drivability. FIG. 8 is a diagram showing: changes in the throttle opening degree TH according to a system of the present embodiment where the throttle opening degree TH used for finding the target engine revolution number is changed on the bases of the throttle opening degree variation ATH; and changes in a value used for finding the target engine revolution number, which are associated with changes in the throttle opening degree TH. As shown in this diagram, even when the throttle opening degree TH suddenly changes, the value used for finding the target engine revolution number rises up more gently than the throttle opening degree TH. Accordingly, even at the time of sudden throttle opening, the target engine revolution number Netgt changes gently, and the kick-down becomes appropriate in view of drivability. FIG. 13 is an overall configuration view of a fuel injection control system, which is one embodiment of the present invention. An intake port 24 and an exhaust port 25 are open in a combustion chamber 23 of an engine 100. In each of the ports 24 and 25, an intake valve 26 and an exhaust valve 27 are respectively provided. Further, an ignition coil 28a and an ignition plug 29b are provided. In an intake passage 29 leading to the intake port 24, a throttle 30 for adjusting an intake air flow amount according to the opening degree TH thereof and the throttle sensor 21 for detecting a throttle opening degree are provided. On the downstream side thereof, a negative pressure sensor 33 for detecting an intake negative pressure PB and a fuel injection valve 34 are placed. An air cleaner 35 is provided at an end of the intake passage 29. In the air cleaner 35, an air filter 36 and an intake air temperature sensor 37 for detecting intake air (atmosphere) temperature TA are provided. Through this air filter 36, outside air is taken into the intake passage 29. An engine revolution number sensor 22 is placed for detecting a reluctor provided on the periphery of a rotor (outer rotor) 40 of the ACG coupled to the crankshaft 2 which is coupled to a piston 38 of the engine 100 through a connecting rod 39, and for outputting an engine revolution number Ne. Moreover, a driven pulley revolution number sensor 16 for generating an output representing a vehicle speed V is provided on a side surface of a driven side pulley 10 of the continuously variable transmission 1. A water temperature sensor 41 for detecting cooling water temperature TW representing an engine temperature is provided in a water jacket formed around the engine 100. An engine control ECU 42 includes a fuel injection control unit 43 and an ignition control unit 44. The fuel injection control unit 43 determines fuel injection amount on the bases of a plurality of parameters including the engine revolution number Ne and the throttle opening degree TH, and outputs an injection signal Tout. The injection signal Tout is a pulse signal having a pulse width depending on the fuel injection amount. The fuel injection valve 34 is opened for a time corresponding to this pulse width to inject fuel. A calculation unit for the injection signal Tout may be configured using injection time maps which output an injection time Tout according to various kinds of parameters inputted. The injection time maps are prepared for the driving modes, respectively. The ignition control unit 44 determines an output timing (ignition timing) of an ignition signal supplied to the ignition coil 28a. A calculation unit for the ignition timing includes a setting unit for the ignition timing set up fixedly and an advance/retardation correction unit for advancing or retarding the ignition timing on the bases of parameters including the cooling water temperature TW representing a driving state of the engine 100. The advance/retardation correction unit may be configured using ignition timingmaps which output an ignition timing signal according to the parameters inputted. The injection timing maps are prepared for the driving modes, respectively. FIG. 12 is a functional block diagram of essential parts of this embodiment. When a driving mode is selected by the mode switch 19, the transmission map corresponding to the selected driving mode is selected in the transmission control ECU 17. The case where the number of selectable driving modes is n is supposed, and transmission maps 45 are set from No. 1 to No. n. The transmission map 45 outputs a target number Netgt of engine revolutions based on the throttle opening degree TH and the vehicle speed V. A motor driver 4 6 controls the transmission ratio of the continuously variable transmission 1 by driving the motor 7 so that the engine revolution number Netgt becomes the target engine revolution number Netgt. An engine control map control unit 47 detects the driving mode by the switching of the mode switch 19, and outputs a selection signal depending on the driving mode. In the engine control ECU 42, n ignition timing maps 48 and n injection time maps 49 are provided to correspond to the number of driving modes. The ignition timing map 48 and the injection time map 49 corresponding to the driving mode are selected respectively, according to the selection signal outputted from the engine control map selection unit 47. The ignition timing map 48 and the injection time map 49 output optimum ignition timing and fuel injection time according to the throttle opening degree TH, the engine water temperature TW, the intake air temperature TA, the vehicle speed V, the negative pressure PB, and the like. An ignition driver 50 causes the ignition coil 28a to be energized at the ignition timing outputted from the ignition timing map 48, and the ignition plug 28b is ignited. An injection valve driver 52 drives the fuel injection valve 34 for the injection time Tout outputted from the injection time map 49, thus injecting fuel. Incidentally, in this embodiment, means for outputting the target engine revolution number is a map. However, the present invention is also applicable to the case where calculation means for calculating the target engine revolution number by a calculation based on the throttle opening degree TH and the vehicle speed V is provided instead of this map. In this case, the transmission characteristic for each driving mode may be changed by switching an operation expression depending on the selected driving mode or switching a coefficient used in the operation expression. Moreover, the throttle opening degree TH and the vehicle speed V used to search a map may be corrected using predetermined correction values for each driving mode. Similarly, the maps for outputting the ignition timing and the injection time may also be substituted by operation expressions. Furthermore, in this embodiment, the transmission map for the power train control ECU is determined, and then the ignition timing map and the injection timing map for the engine control ECU are switched depending on the transmission map. However, the maps on the engine control ECU side may be selected first, and then the transmission map for the power train control ECU may be selected in a cooperative manner. [Brief Description of the Drawings] [FIG. 1] FIG. 1 is a block diagram showing functions of important units of a transmission controlling system according to one embodiment of the present invention. [FIG. 2] FIG. 2 is a system configuration diagram of a continuously variable transmission control system according to the one embodiment of the invention. [FIG. 3] FIG. 3 is a chart showing one example of a map where a relation between a ATH judgment value and a vehicle speed V is established. [FIG. 4] FIG. 4 is a chart showing an example of a map with respect to a sudden opening time additional value. [FIG. 5] FIG. 5 is a chart showing an example of a map with respect to a normal condition time additional value. [FIG. 6] FIG. 6 is a flowchart for a throttle opening degree correcting process. [FIG. 7] FIG. 7isa diagram showing values used for finding a target engine revolution number which are associated with changes in a throttle opening degree TH according to a conventional system, the throttle opening degree TH not depending on a throttle opening degree variation ATH. [FIG. 8] FIG. 8 is a diagram showing values used for finding a target engine revolution number which are associated with changes in a throttle opening degree TH according to a system of the one embodiment, the throttle opening degree TH being changed depending on the throttle opening degree variation ATH. [FIG. 9] FIG. 9 is a chart showing one example of a map used for obtaining the target engine revolution number Netgt. [FIG. 10] FIG. 10 is a chart showing one example of a transmission characteristic of a low fuel consumption driving mode. [FIG. 11] FIG. 11 is a chart showing one example of a transmission characteristic of a sport driving mode. [FIG. 12] FIG. 12 is a block diagram showing the functions of essential parts of a vehicle control system according to one embodiment of the present invention. [FIG. 13] FIG. 13 is a block diagram of a system including an engine to which the vehicle control system according to the one embodiment of the present invention is applied. [Description of Reference Numerals] 1 CONTINUOUSLY VARIABLE TRANSMISSION 2 CRANKSHAFT 3 DRIVE PULLEY 7 MOTOR 14 V BELT 16 DRIVEN SHAFT REVOLUTION NUMBER SENSOR 17 TRANSMISSION CONTROL ECU (POWER TRAIN CONTROL ECU) 19 MODE SWITCH 21 THROTTLE SENSOR 22 ENGINE REVOLUTION NUMBER SENSOR 28a IGNITION COIL 34 FUEL INJECTION VALVE 4 2 ENGINE CONTROL ECU 4 5 TRANSMISSION MAP 48 IGNITION TIMING MAP 4 9 INJECTION TIME MAP 73 TARGET ENGINE REVOLUTION NUMBER CALCULATING UNIT 74 ADDING UNIT 78 THROTTLE OPENING DEGREE VARIATION JUDGING UNIT [Document Name] Drawings [FIG. 1] VEHICLE SPEED V 80: FIRST ADDITIONAL VALUE STORING UNIT ATH LARGE 78: THROTTLE OPENING DEGREE VARIATION JUDGING UNIT 79: ATH JUDGMENT VALUE STORING UNIT VEHICLE SPEED V 81: SECOND ADDITIONAL VALUE STORING UNIT ATH SMALL 77: MEMORY (CURRENT VALUE) 76: MEMORY (PREVIOUS VALUE) 21: THROTTLE SENSOR 16: DRIVEN PULLEY REVOLUTION NUMBER SENSOR 23: TARGET ENGINE REVOLUTION NUMBER CALCULATING UNIT 22: ENGINE REVOLUTION NUMBER SENSOR 24: MOTOR CONTROL VALUE DETERMINING UNIT 7: MOTOR [FIG. 2] 18: BUTTERY 22: ENGINE REVOLUTION NUMBER SENSOR 20: CHANGE SWITCH 19: MODE SWITCH 21: THROTTLE SENSOR 17: TRANSMISSION CONTROL ECU [FIG. 3] ATH JUDGMENT VALUE VEHICLE SPEED [FIG. 4] TH CHANGE VALUE FOR ATH TRANSMISSION MAP SEARCH VEHICLE SPEED [FIG. 5] TH CHANGE VALUE FOR TRANSMISSION MAP SEARCH FOR NORMAL CONDITIONS VEHICLE SPEED [FIG. 6] THROTTLE OPENING DEGREE CORRECTION READS IN VEHICLE SPEED V READS OUT ATH JUDGMENT VALUE ATH = THO - (TH-1) ATH > ATH JUDGMENT VALUE ADDITIONAL VALUE FOR SEARCH = SUDDEN OPENING TIME ADDITIONAL VALUE ADDITIONAL VALUE FOR SEARCH = NORMAL CONDITION TIME ADDITIONAL VALUE TH = THO + ADDITIONAL VALUE FOR SEARCH RETURN [FIG. 7] THROTTLE OPENING DEGREE LARGE SMALL VALUE USED FOR FINDING TARGET ENGINE REVOLUTION NUMBER LARGE SMALL [FIG. 8] THROTTLE OPENING DEGREE LARGE SMALL VALUE USED FOR FINDING TARGET ENGINE REVOLUTION NUMBER LARGE SMALL [FIG. 9] TARGET ENGINE REVOLUTION NUMBER NETGT THROTTLE OPENING DEGREE TH VEHICLE SPEED V [FIG. 10] ENGINE REVOLUTION NUMBER LOW FUEL CONSUMPTION DRIVING MODE VEHICLE SPEED [FIG. 11] ENGINE REVOLUTION NUMBER SPORT DRIVING MODE VEHICLE SPEED [FIG. 12] 7 MOTOR 17 TRANSMISSION CONTROL ECU 19 MODE SWITCH 28a IGNITION COIL 28b IGNITION PLUG 34 INJECTION VALVE 42 ENGINE CONTROL ECU 45 TRANSMISSION MAP 46 MOTOR DRIVER 47 ENGINE CONTROL MAP SELECTION UNIT 48 IGNITION TIMING MAP 49 INJECTION TIME MAP 50 IGNITION DRIVER 52 INJECTION VALVE DRIVER [FIG. 13] TA INTAKE AIR TEMPERATURE PB NEGATIVE PRESSURE TW WATER TEMPERATURE V VEHICLE SPEED Ne ENGINE REVOLUTION NUMBER 42 ENGINE CONTROL ECU 43 FUEL INJECTION CONTROL UNIT 44 IGNITION CONTROL UNIT [Document Name] Scope of Claims [Claim 1] A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: control maps provided in the engine control ECU, the control maps corresponding to a plurality of driving modes, respectively; and means for selecting from the control maps the control map corresponding to driving mode information set up in the power train control ECU, wherein the engine control ECU is controlled according to control information obtained by searching the selected control map. [Claim 2] A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, wherein each of the engine control ECU and the power train control ECU has a plurality of control parameter output means applicable respectively to a plurality of vehicle driving modes, the vehicle control system comprising means for selecting one control parameter output means both from the plurality of control parameter output means provided in the engine control ECU and one from the plurality of control parameter output means provided in the power train control ECU according to the vehicle driving mode selected. [Claim 3] A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: an actuator for adjusting a transmission ratio of the continuously variable transmission; and a mode switch for selecting a driving mode of a vehicle, the power train ECU comprising: target engine revolution number output means for outputting an engine revolution number corresponding to the driving mode; and a driver for supplying the actuator with a drive instruction to converge an actual revolution number of the engine on the target engine revolution number, the engine control ECU comprising: a plurality of ignition timing output means for outputting ignition timing depending on the driving mode of the vehicle; a plurality of injection time output means for outputting a fuel injection time depending on the driving mode of the vehicle; an ignition driver for supplying a drive signal to an ignition plug according to the ignition timing; and an injection valve driver for supplying a drive signal to a fuel injection valve according to the fuel injection time. [Claim 4] A control system for a belt-type continuously variable transmission installed in a vehicle, comprising: means for detecting a throttle opening degree; means for detecting a speed of the vehicle; means for detecting an engine revolution number; an actuator which changes transmission ratios; target value outputting means for outputting a target engine revolution number as a function of the throttle opening degree and a vehicle speed, the target engine revolution number being larger as the throttle opening degree is larger; transmission characteristic determining means for determining a driving direction and a driving speed of the actuator on the bases of the target engine revolution number and an actual engine revolution number; means for outputting a throttle opening degree variation judgment value in accordance with the vehicle speed; throttle opening degree variation judging means for judging whether a throttle opening degree variation every predetermined process cycle is larger than the throttle opening degree variation judgment value; adding means for adding, if the throttle opening degree variation is larger than the throttle opening degree variation judgment value, a first throttle opening degree variation additional value to a throttle opening degree intended to be inputted to the target value outputting means, the adding means for adding, if the throttle opening degree variation is smaller than the throttle opening degree variation judgment value, a second throttle opening degree variation additional value to a throttle opening degree intended to be inputted to the target value outputting means, the second throttle opening degree variation additional value being larger than the first throttle opening degree variation additional value.

Full Text

[Document Name] Specification
[Title of the Invention] VEHICLE CONTROL SYSTEM, CONTINUOUSLY VARIABLE TRANSMISSION CONTROL SYSTEM AND METHOD [Technical Field of the Invention]
The present invention relates to a vehicle control system, a continuously variable transmission control system and a method. In particular, the present invention relates to a vehicle control system in which an engine control ECU for controlling fuel injection and ignition and a power train control ECU for controlling a transmission are caused to operate in cooperation, and a continuously variable transmission system and a method which are suitable for changing transmission characteristics in accordance with a throttle opening degree variation to obtain smooth acceleration performance (drivability). [Background Art]
A cooperative control system in which an engine and a transmission operate in cooperation is known to reduce shocks to a vehicle which are caused by activation of variable mechanisms of the engine, such as an intake switch valve and a torque converter, and by the activation of the transmission (see Japanese Unexamined Patent Publication No. 2001-39183). The states of the variable mechanisms during the gearshift, such as an early, intermediate, or later phase of a gearshift, are controlledbased on the kind of the gearshift.
On the other hand, Japanese Unexamined Patent Publication No. 2003-239774 discloses an engine control system which makes it possible to ensure a driving force and drivability of a vehicle by controlling activation characteristics of intake valves and exhaust valves when transmission control comes not to be normally executed.

Japanese Patent Application publication No. Hei7-239016 discloses a transmission control system which is configured in a configuration for shifting transmission patterns in accordance with a driving state of a vehicle in order that, when a vehicle in a specific driving state, such as driving in heavy traffic or in a residential area, has exited this specific driving state, if there is no change between transmission stages before and after the specific driving state, a judgment that the vehicle has come out of the specific driving state can be delayed. This control makes it possible to promote suppression of transmission shock by avoiding frequent changes in driving state judgment parameters, the changes being attributable to an unintentional accelerator operation, noises and the like.
Additionally, there has been known a control system which, in a belt-type continuously variable transmission coupled to an internal combustion engine (hereinafter, referred to as an "engine"), controls a pulley ratio by allowing a movable half of a drive pulley to slide in a direction of an output shaft of the engine (Japanese Patent Application publication No. Hei6-123321). In this control system, a target ratio is determined by performing a map search based on a throttle opening degree and a vehicle speed, and a motor is driven in order that this target ratio can be obtained. Furthermore, a duty ratio of the motor is increased according to a magnitude of a difference between the target ratio and an actual pulley ratio, and a duty is controlled in accordance with ON and OFF states of an accelerator. By this control, smooth actions, which arematched with transmission requirements according to driving situations, of the transmission are expected.
[Patent Document 1] Japanese Unexamined Patent

Publication No. 2001-39183
[Patent Document 2 ] Japanese Unexamined Patent Publication No. 2003-239774
[Patent Document 3] Japanese Patent Application publication No. Hei7-239016
[ Patent Document 4 ] Japanese Patent Application publication No. Hei6-123351 [Disclosure of the Invention] [Problems to be Solved by the Invention]
In the control systems described in Patent Documents 1 and 2, transmission control and engine control are made to have a certain relationship, but fuel injection control and ignition control are not performed in relation to the shift mode of a transmission. For example, it is possible to conceive of a two-wheeled motor vehicle in which selection of one from a manual shift mode and a plurality of automatic shift modes makes driving possible. An engine control system mounted on such a vehicle is desired to be capable of operating in relation to a transmission control system for each shift mode from the viewpoint of improvement of fuel economy, quietness, and the like, for each shift mode.
One object of the present invention is to provide a vehicle control system in which a power train control ECU and an engine control ECU are separate bodies and in which optimum fuel injection and ignition can be performed depending on a shift mode.
In the continuously variable transmission control system in Patent Document 4, a target engine revolution number is obtained by performing a map search based on a throttle opening degree and a vehicle speed, and a pulley ratio, i.e., a

transmission ratio is controlled in order that the target engine revolution number can be reached. In this case, the target engine revolution number is uniquely determined with the throttle opening degree. Accordingly, for example, when an operation of suddenly opening a throttle valve is made under a transmission characteristic suitable for normal driving, there is a possibility of fail ing to obtain an appropriate kick-down amount. Therefore, there is a possibility that drivability may be reduced because driving states cannot be changed smoothly.
Another object of the present invention is to provide a continuously variable transmission control system, and a method, which are capable of obtaining an appropriate variation in transmission ratio regardless of opening or closing speed of a throttle valve. [Means for Solving the Problems]
The present invention for achieving the objects mentioned above has a first characteristic in a configuration of a vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, wherein a control map corresponding to a driving mode information set up in the power train control ECU is selected from control maps provided in the engine control to correspond to a plurality of driving modes, the engine control ECU being controlled according to control information found from the selected control map.
Moreover, the present invention has a second characteristic in the vehicle control system having an engine control ECU for controlling an engine and a power train control

ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: a plurality of control parameter output means applicable respectively to a plurality of vehicle driving modes; and means for selecting one control parameter output means both from the plurality of control parameter output means provided in the engine control ECU and one from the plurality of control parameter output means provided in the power train control ECU according to the vehicle driving mode selected.
Furthermore, the present invention has a third characteristic in a vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising: an actuator for adjusting a transmission ratio of the continuously variable transmission; and a mode switch for selecting a driving mode of a vehicle, the power train ECU comprising: target engine revolution number output means for outputting an engine revolution number corresponding to the driving mode; and a driver for supplying the actuator with a drive instruction to converge an actual revolution number of the engine on the target engine revolution number, the engine control ECU comprising: a plurality of ignition timing output means for outputting ignition timing depending on the driving mode of the vehicle; a plurality of injection time output means for outputting a fuel injection time depending on the driving mode of the vehicle; an ignition driver for supplying a drive signal to an ignition plug according to the ignition timing;

and an injection valve driver for supplying a drive signal to a fuel injection valve according to the fuel injection time.
Besides, the present invention for achieving the objects mentioned above is characterized by a method of a continuously variable transmission control with which the target engine revolution number of the continuously variable transmission control system installed in a vehicle is decided depending on the throttle opening degree and the vehicle speed, the method comprising the steps of: setting the target engine revolution number larger as the throttle opening degree is larger; and adding, if a variation of the throttle opening degree with respect to each of predetermined process cycles is larger than a threshold value according to the vehicle speed, a first value to a throttle opening degree which determines the target engine revolution number, and adding, if the variation of the throttle opening degree is smaller than the threshold value, a second value larger than the first value to the throttle opening degree which determines the target engine revolution number. [Effect of the Invention]
According to the present invention having the aforementioned first characteristic, when a driving mode is set up in the engine drive control ECU, the control map corresponding to the driving mode is selected among the control maps provided in the engine control ECU and used to control the engine control ECU.
Further, according to the second and third characteristics, the control parameter output means corresponding to the driving mode is selected from the plurality of control parameter output means provided in each of the engine control ECU and the power train control ECU. Thus, the engine control ECU and the power

train control ECU are controlled on the bases of the driving mode to operate in cooperation. Accordingly, engine control including appropriate fuel injection and ignition timing depending on the shift mode of a continuously variable transmission isperformed, andperformance, such as fuel economy, quietness, and drivability, which is in response to the driving mode, can be obtained.
According to the present invention characterized as above, the throttle opening degree used for determining the target engine revolution number is corrected on the bases of whether a throttle opening degree variation in predetermined unit time is larger than a threshold value preset in accordance with a vehicle speed. That is, if the throttle opening degree variation in predetermined unit time is larger than the threshold value, a small value is added to the throttle opening degree used for determining the target engine revolution number. On the other hand, if the throttle opening degree variation per predetermined unit time is smaller than the threshold value, a large value is added to the throttle opening degree used for determining the target engine revolution number. Thus, when a throttle is suddenly opened, the throttle opening degree used for determining the target engine revolution number is made smaller than it is when the throttle is in normal operation. Accordingly, even when the throttle is suddenly opened, a sudden increase in engine revolution number is avoided, whereby there is no possibility that a kick-down amount may become too large. [Best Modes for Carrying out the Invention]
Hereinafter, one embodiment of the present invention will be described by referring to the drawings. FIG. 2 is a system configuration diagram of a continuously variable transmission

control system according to the one embodiment of the present invention. A continuously variable transmission 1 is coupled to a crankshaft, i.e., an output shaft 2 of an engine (not illustrated) which is a drive source of, for example, a scooter. A drive pulley 3 is composed of: a fixed pulley half 31; and a movable pulley half 32 provided to the output shaft 2 so as to be freely slidable in an axial direction of the output shaft 2. To an outer periphery of a hub of the movable pulley half 32, a slider 5 is supported through a bearing 4. A gear 51 is formed on the periphery of the slider 5. The gear 51 engages with a final-stage gear 64 of a decelerator 6 composed of four gears 61, 62, 63 and 64, and the first-stage gear 61 of the decelerator 6 engages with an output gear 71 of the motor 7. A male screw formed on an outer periphery of a cylinder 9 fixed to a case 8 is screwed into a female screw formed on an inner periphery of the slider 5.
When the slider 5 is rotated by revolution of the motor 7, the female screw on the slider 5 rotates around the male screw on the cylinder 9, and a feeding action in an axial direction of the screw allows the slider 5 to move in the axial direction of the output shaft 2 . This move of the slider 5 changes a distance between the fixed pulley half 31 and the movable pulley half 32 of the drive pulley 3.
A driven pulley 10 of the continuously variable transmission 1 is supported by a driven shaft 11. The driven pulley 10 is composed of a movable pulley half 101 and a fixed pulley half 102, which are both freely rotatable with respect to the driven shaft 11. Furthermore, the movable pulley half 101 is also freely slidable with respect to the driven shaft 11 in an axial direction thereof, and is energized toward the

fixed pulley half 102 by a coil spring 103. A centrifugal clutch 12 is provided to the driven shaft 11, and the movable pulley half 101 is coupled with the driven shaft 11 through the centrifugal clutch 12. A V-belt 14 is hung on the drive pulley 3 and the driven pulley 10.
A position sensor 15 for detecting a reset position of the movable pulley half 32 of the drive pulley 3 is provided so as to be close to the outer periphery of the movable pulley half 32 . Additionally, a driven pulley revolution number sensor 16 for detecting a revolution number of a driven shaft 11 is arranged so as to face a magnetic substance (not illustrated) which rotates with the driven pulley 10.
As a control system for the continuously variable transmission 1, a transmission control ECU 17 for driving the motor 7 is provided. The transmission control ECU 17 includes a microcomputer, and receives power supply from a buttery 18.
In the scooter, a mode switch 19 used for selecting a driving mode is provided- In accordance with a driving mode, a transmission characteristic is selected from a manual mode and a plurality of automatic modes. A change switch 20 outputs a change signal CH for shifting transmission stages in a direction toward a higher transmission stage, or in a direction toward a lower transmission stage. The change switch 20 becomes effective under the manual mode, and a transmission stage is selected in accordance with the change signal CH. Under the manual mode, the motor 7 is driven so as to set up a predetermined pulley ratio with respect to each of transmission stages. The pulley ratio is defined as an engine revolution number Nl of the driven pulley 10 in proportion to an engine revolution number NO of the drive pulley 3 (N1/N0) . A throttle sensor 21 detects

an opening degree of a throttle valve of the engine not illustrated, and outputs opening degree information TH. An engine revolution number sensor 22 detects a reluctor, and outputs a revolution number of the ACG, i.e., an engine revolution number Ne, the reluctor being provided in a rotor of an AC generator (ACG) not illustrated which is coupled to the output shaft of the engine.
A description will be given for driving modes. Plural driving modes are set up, and different transmission characteristics exclusively correspond to the respective driving modes. In this embodiment, the manual mode, and, as two automatic modes, a sport driving mode and a low fuel consumption driving mode are set up.
One example of the transmission characteristics of the low fuel consumption driving mode is shown in FIG. 10, and one example of the transmission characteristics of the sport driving mode is shown in FIG. 11.
A plurality of transmission ratios are set up in the manual mode. There, a setup is such that any one of this plurality of transmission ratios maybe designated by use of a change switch 18, and that driving with a transmission ratio which is fixed to this designated ratio is made possible.
In the sport driving mode, powerful driving is made possible with an engine revolution number relatively being high as compared with a normal driving mode, and in the low fuel consumption driving mode, contrary to the sport driving mode, a setup is such that driving with the engine revolution number being low as compared with the normal driving mode is realized.
FIG. 1 is a block diagram showing functions of important units of the transmission control system (the ECU17). Based on the throttle opening degree TH and a vehicle speed V, a target

engine revolution number calculating unit 73 calculates a target engine revolution number Netgt. For example, the target engine revolution number calculating unit 73 can be constituted of maps each of which outputs the target engine revolution number Netgt as a function value defined by the throttle opening degree TH and the vehicle speed V. This map is provided with respect to each of the driving modes . The vehicle speed V can be represented by a revolution number of the driven pulley 10, which is detected by the driven pulley revolution number sensor 16.
FIG. 9 is a chart showing one example of a map used for obtaining the target engine revolution number Netgt. This map is a three-dimensional map with respect to a revolution number of the driven pulley (the vehicle speed V) , the throttle opening degree TH, and the target engine revolution number Netgt. By using this map, a value in a z-axis direction at an intersection point of a value (the vehicle speed V) in an x-axis direction and a value (the throttle opening degree TH) in a y-axis direction is read out as a value indicating the target engine revolution number Netgt. In the example shown in FIG. 9, when the vehicle speed V becomes high to a certain degree, a degree of increase of the target engine revolution number Netgt becomes larger, the increase being associated with increase in the vehicle speed V. That is, where the throttle opening degree TH is relatively small, a degree of increase in the target engine revolution number Netgt becomes larger from the time where the vehicle speed V becomes VI. On the other hand, where the throttle opening degree TH is relatively large, a degree of increase in the target engine revolution number Netgt becomes larger from the time where the vehicle speed V becomes V2 (V2 As a consequence, in this example, the map is, as a whole,

set up in a manner that the target engine revolution number Netgt becomes larger where the throttle opening degree TH is relatively large.
A motor control value determining unit 74 is transmission characteristic determining means, and determines a rotational direction of the motor 7 and a duty, i.e. , a speed, of the motor 7 on the bases of a difference between the target engine revolution number Netgt, which is calculated by the target engine revolution number calculating unit 73, and an actual engine revolution number Ne which is obtained by the engine revolution number sensor 22. If the target engine revolution number Netgt is higher than the actual engine revolution number Ne, the motor 7 is driven in a direction of increasing a distance between the fixed pulley half 31 and the movable pulley half 32 in order to increase the pulley ratio. The motor 7 is driven pursuant to a control value, i.e., a rotational direction of the motor 7, outputted by the motor control value determining unit 74, and pursuant to the target engine revolution number Netgt, whereby the pulley ratio is altered.
Furthermore, for the purpose of obtaining an appropriate kick-down amount when the throttle is suddenly opened, the throttle opening degree is corrected between the time where the throttle is suddenly opened and the time where a throttle is under normal acceleration. An output of the throttle sensor 21 is corrected by addition at an adding unit 75, For example, into memories 76 and 77 which can be configured to be FIFO, the throttle opening degrees TH are read respectively on predetermined interruption cycle bases, and are stored as a previous value and a current value.
In a throttle opening degree variation judging unit 78,

a difference ATH between a previous value TH-1 of the throttle opening degree and a current value THO of the throttle opening degree TH is compared with a predetermined ATH judgment value, i.e., a threshold value. The ATH judgment value is set up as a map as a function of the vehicle speed V in a ATH judgment value storing unit 79. In FIG. 3, one example of a map where a relation between the ATH judgment value and the vehicle speed V is established.
A throttle opening degree additional value is selected depending on whether a change ATH of the throttle opening degree is larger or smaller than the ATH judgment value. There are provided: a first additional value storing unit 80 where a map of a throttle opening degree additional value (sudden opening time additional value) in a case where the change ATH in the throttle opening degree TH is larger than the ATH judgment value is stored; and a second additional value storing unit 81 where a map of a throttle opening degree additional value (normal condition time additional value) in a case where the change ATH of the throttle opening degree TH is smaller than the ATH judgment value is stored.
FIG. 6 is a flowchart for a throttle opening degree correcting process. In Step SI, an output of the driven pulley revolution number sensor 16 is read in as the vehicle speed V. In Step S2, the ATH judgment value according to the vehicle speed is read out, for example, from the map shown in FIG. 3. In Step
53, by subtracting the throttle opening degree previous value
TH-1 from the throttle opening degree current value THO, the
throttle opening degree variation ATH is calculated. In Step
54, it is judged whether the throttle opening degree variation
ATH is at least the ATH judgment value.

If the judgment is positive in Step S4, the process is progressed to Step S5, where the throttle opening degree additional value for search in a transmission map at the time of sudden throttle opening, i.e., the sudden opening time additional value is read out from the first additional value storing unit 80, and is set as an additional value for search. If the judgment is negative in Step S4, the process is progressed to Step S6, where the throttle opening degree additional value for search in a transmission map under normal conditions, i.e., the normal condition time additional value is read out from the second additional value storing unit 81, and is set as the additional value for search. In Step S7, a value obtained by adding the additional value for search to the throttle opening degree current value THO is set as the throttle opening degree TH. The target engine revolution number Netgt is found by using this throttle opening degree TH, the motor 7 is driven so that the target engine revolution number Netgt can be obtained, and kick-down is carried out.
As can be understood from FIGs. 4 and 5, the sudden opening time additional value is small as compared with the normal condition time additional value. Accordingly, in a case where the current throttle opening degree THO is the same, the throttle opening degree TH for search at the time of sudden throttle opening is recognized at the target engine revolution number calculating unit 73 as a value smaller than the throttle opening degree TH under normal acceleration.
As a result, even at the time of sudden throttle opening, the target engine revolution number Netgt does not change so much from the current value, whereby a sharp kick-down can be suppressed.

FIG. 7 is a diagram showing: changes in the throttle opening degree TH according to a conventional system where the throttle opening degree TH used for finding a target engine revolution number is not changed on the bases of the throttle opening degree variation ATH; and changes in a value used for finding the target engine revolution number, which are associated with changes in the throttle opening degree TH. As shown in this diagram, the throttle opening degree TH and the value used for finding the target engine revolution number are substantially equal to each other. Therefore, at the time of sudden throttle opening, the target engine revolution number Netgt also suddenly changes, and the kick-down also becomes larger than the kick-back in an appropriate state in view of drivability.
FIG. 8 is a diagram showing: changes in the throttle opening degree TH according to a system of the present embodiment where the throttle opening degree TH used for finding the target engine revolution number is changed on the bases of the throttle opening degree variation ATH; and changes in a value used for finding the target engine revolution number, which are associated with changes in the throttle opening degree TH. As shown in this diagram, even when the throttle opening degree TH suddenly changes, the value used for finding the target engine revolution number rises up more gently than the throttle opening degree TH. Accordingly, even at the time of sudden throttle opening, the target engine revolution number Netgt changes gently, and the kick-down becomes appropriate in view of drivability.
FIG. 13 is an overall configuration view of a fuel injection control system, which is one embodiment of the present invention. An intake port 24 and an exhaust port 25 are open in a combustion chamber 23 of an engine 100. In each of the ports 24 and 25,

an intake valve 26 and an exhaust valve 27 are respectively provided. Further, an ignition coil 28a and an ignition plug 29b are provided.
In an intake passage 29 leading to the intake port 24, a throttle 30 for adjusting an intake air flow amount according to the opening degree TH thereof and the throttle sensor 21 for detecting a throttle opening degree are provided. On the downstream side thereof, a negative pressure sensor 33 for detecting an intake negative pressure PB and a fuel injection valve 34 are placed. An air cleaner 35 is provided at an end of the intake passage 29. In the air cleaner 35, an air filter 36 and an intake air temperature sensor 37 for detecting intake air (atmosphere) temperature TA are provided. Through this air filter 36, outside air is taken into the intake passage 29.
An engine revolution number sensor 22 is placed for detecting a reluctor provided on the periphery of a rotor (outer rotor) 40 of the ACG coupled to the crankshaft 2 which is coupled to a piston 38 of the engine 100 through a connecting rod 39, and for outputting an engine revolution number Ne. Moreover, a driven pulley revolution number sensor 16 for generating an output representing a vehicle speed V is provided on a side surface of a driven side pulley 10 of the continuously variable transmission 1. A water temperature sensor 41 for detecting cooling water temperature TW representing an engine temperature is provided in a water jacket formed around the engine 100.
An engine control ECU 42 includes a fuel injection control unit 43 and an ignition control unit 44. The fuel injection control unit 43 determines fuel injection amount on the bases of a plurality of parameters including the engine revolution number Ne and the throttle opening degree TH, and outputs an

injection signal Tout. The injection signal Tout is a pulse signal having a pulse width depending on the fuel injection amount. The fuel injection valve 34 is opened for a time corresponding to this pulse width to inject fuel. A calculation unit for the injection signal Tout may be configured using injection time maps which output an injection time Tout according to various kinds of parameters inputted. The injection time maps are prepared for the driving modes, respectively.
The ignition control unit 44 determines an output timing (ignition timing) of an ignition signal supplied to the ignition coil 28a. A calculation unit for the ignition timing includes a setting unit for the ignition timing set up fixedly and an advance/retardation correction unit for advancing or retarding the ignition timing on the bases of parameters including the cooling water temperature TW representing a driving state of the engine 100. The advance/retardation correction unit may be configured using ignition timingmaps which output an ignition timing signal according to the parameters inputted. The injection timing maps are prepared for the driving modes, respectively.
FIG. 12 is a functional block diagram of essential parts of this embodiment. When a driving mode is selected by the mode switch 19, the transmission map corresponding to the selected driving mode is selected in the transmission control ECU 17. The case where the number of selectable driving modes is n is supposed, and transmission maps 45 are set from No. 1 to No. n. The transmission map 45 outputs a target number Netgt of engine revolutions based on the throttle opening degree TH and the vehicle speed V. A motor driver 4 6 controls the transmission ratio of the continuously variable transmission 1 by driving

the motor 7 so that the engine revolution number Netgt becomes the target engine revolution number Netgt.
An engine control map control unit 47 detects the driving mode by the switching of the mode switch 19, and outputs a selection signal depending on the driving mode.
In the engine control ECU 42, n ignition timing maps 48 and n injection time maps 49 are provided to correspond to the number of driving modes. The ignition timing map 48 and the injection time map 49 corresponding to the driving mode are selected respectively, according to the selection signal outputted from the engine control map selection unit 47.
The ignition timing map 48 and the injection time map 49 output optimum ignition timing and fuel injection time according to the throttle opening degree TH, the engine water temperature TW, the intake air temperature TA, the vehicle speed V, the negative pressure PB, and the like. An ignition driver 50 causes the ignition coil 28a to be energized at the ignition timing outputted from the ignition timing map 48, and the ignition plug 28b is ignited. An injection valve driver 52 drives the fuel injection valve 34 for the injection time Tout outputted from the injection time map 49, thus injecting fuel.
Incidentally, in this embodiment, means for outputting the target engine revolution number is a map. However, the present invention is also applicable to the case where calculation means for calculating the target engine revolution number by a calculation based on the throttle opening degree TH and the vehicle speed V is provided instead of this map. In this case, the transmission characteristic for each driving mode may be changed by switching an operation expression depending on the selected driving mode or switching a coefficient used

in the operation expression. Moreover, the throttle opening degree TH and the vehicle speed V used to search a map may be corrected using predetermined correction values for each driving mode. Similarly, the maps for outputting the ignition timing and the injection time may also be substituted by operation expressions.
Furthermore, in this embodiment, the transmission map for the power train control ECU is determined, and then the ignition timing map and the injection timing map for the engine control ECU are switched depending on the transmission map. However, the maps on the engine control ECU side may be selected first, and then the transmission map for the power train control ECU may be selected in a cooperative manner. [Brief Description of the Drawings]
[FIG. 1] FIG. 1 is a block diagram showing functions of important units of a transmission controlling system according to one embodiment of the present invention.
[FIG. 2] FIG. 2 is a system configuration diagram of a continuously variable transmission control system according to the one embodiment of the invention.
[FIG. 3] FIG. 3 is a chart showing one example of a map where a relation between a ATH judgment value and a vehicle speed V is established.
[FIG. 4] FIG. 4 is a chart showing an example of a map with respect to a sudden opening time additional value.
[FIG. 5] FIG. 5 is a chart showing an example of a map with respect to a normal condition time additional value.
[FIG. 6] FIG. 6 is a flowchart for a throttle opening degree correcting process.
[FIG. 7] FIG. 7isa diagram showing values used for finding

a target engine revolution number which are associated with changes in a throttle opening degree TH according to a conventional system, the throttle opening degree TH not depending on a throttle opening degree variation ATH.
[FIG. 8] FIG. 8 is a diagram showing values used for finding a target engine revolution number which are associated with changes in a throttle opening degree TH according to a system of the one embodiment, the throttle opening degree TH being changed depending on the throttle opening degree variation ATH.
[FIG. 9] FIG. 9 is a chart showing one example of a map used for obtaining the target engine revolution number Netgt.
[FIG. 10] FIG. 10 is a chart showing one example of a transmission characteristic of a low fuel consumption driving mode.
[FIG. 11] FIG. 11 is a chart showing one example of a transmission characteristic of a sport driving mode.
[FIG. 12] FIG. 12 is a block diagram showing the functions of essential parts of a vehicle control system according to one embodiment of the present invention.
[FIG. 13] FIG. 13 is a block diagram of a system including an engine to which the vehicle control system according to the one embodiment of the present invention is applied. [Description of Reference Numerals]
1 CONTINUOUSLY VARIABLE TRANSMISSION
2 CRANKSHAFT
3 DRIVE PULLEY
7 MOTOR
14 V BELT
16 DRIVEN SHAFT REVOLUTION NUMBER SENSOR
17 TRANSMISSION CONTROL ECU (POWER TRAIN CONTROL ECU)

19 MODE SWITCH
21 THROTTLE SENSOR
22 ENGINE REVOLUTION NUMBER SENSOR
28a IGNITION COIL
34 FUEL INJECTION VALVE
4 2 ENGINE CONTROL ECU
4 5 TRANSMISSION MAP
48 IGNITION TIMING MAP
4 9 INJECTION TIME MAP
73 TARGET ENGINE REVOLUTION NUMBER CALCULATING UNIT
74 ADDING UNIT
78 THROTTLE OPENING DEGREE VARIATION JUDGING UNIT

[Document Name] Drawings [FIG. 1]
VEHICLE SPEED V
80: FIRST ADDITIONAL VALUE STORING UNIT ATH LARGE
78: THROTTLE OPENING DEGREE VARIATION JUDGING UNIT 79: ATH JUDGMENT VALUE STORING UNIT VEHICLE SPEED V
81: SECOND ADDITIONAL VALUE STORING UNIT ATH SMALL
77: MEMORY (CURRENT VALUE) 76: MEMORY (PREVIOUS VALUE) 21: THROTTLE SENSOR
16: DRIVEN PULLEY REVOLUTION NUMBER SENSOR 23: TARGET ENGINE REVOLUTION NUMBER CALCULATING UNIT 22: ENGINE REVOLUTION NUMBER SENSOR 24: MOTOR CONTROL VALUE DETERMINING UNIT 7: MOTOR
[FIG. 2]
18: BUTTERY
22: ENGINE REVOLUTION NUMBER SENSOR
20: CHANGE SWITCH
19: MODE SWITCH
21: THROTTLE SENSOR
17: TRANSMISSION CONTROL ECU
[FIG. 3]
ATH JUDGMENT VALUE
VEHICLE SPEED

[FIG. 4]
TH CHANGE VALUE FOR ATH TRANSMISSION MAP SEARCH
VEHICLE SPEED
[FIG. 5]
TH CHANGE VALUE FOR TRANSMISSION MAP SEARCH FOR NORMAL CONDITIONS
VEHICLE SPEED
[FIG. 6]
THROTTLE OPENING DEGREE CORRECTION READS IN VEHICLE SPEED V READS OUT ATH JUDGMENT VALUE ATH = THO - (TH-1) ATH > ATH JUDGMENT VALUE
ADDITIONAL VALUE FOR SEARCH = SUDDEN OPENING TIME ADDITIONAL VALUE
ADDITIONAL VALUE FOR SEARCH = NORMAL CONDITION TIME ADDITIONAL VALUE
TH = THO + ADDITIONAL VALUE FOR SEARCH RETURN
[FIG. 7] THROTTLE OPENING DEGREE
LARGE
SMALL VALUE USED FOR FINDING TARGET ENGINE REVOLUTION NUMBER
LARGE
SMALL

[FIG. 8] THROTTLE OPENING DEGREE
LARGE
SMALL VALUE USED FOR FINDING TARGET ENGINE REVOLUTION NUMBER
LARGE
SMALL
[FIG. 9]
TARGET ENGINE REVOLUTION NUMBER NETGT THROTTLE OPENING DEGREE TH VEHICLE SPEED V
[FIG. 10]
ENGINE REVOLUTION NUMBER LOW FUEL CONSUMPTION DRIVING MODE VEHICLE SPEED
[FIG. 11]
ENGINE REVOLUTION NUMBER SPORT DRIVING MODE VEHICLE SPEED
[FIG. 12]
7 MOTOR
17 TRANSMISSION CONTROL ECU
19 MODE SWITCH
28a IGNITION COIL
28b IGNITION PLUG
34 INJECTION VALVE

42 ENGINE CONTROL ECU
45 TRANSMISSION MAP
46 MOTOR DRIVER
47 ENGINE CONTROL MAP SELECTION UNIT
48 IGNITION TIMING MAP
49 INJECTION TIME MAP
50 IGNITION DRIVER
52 INJECTION VALVE DRIVER
[FIG. 13]
TA INTAKE AIR TEMPERATURE
PB NEGATIVE PRESSURE
TW WATER TEMPERATURE
V VEHICLE SPEED
Ne ENGINE REVOLUTION NUMBER
42 ENGINE CONTROL ECU
43 FUEL INJECTION CONTROL UNIT
44 IGNITION CONTROL UNIT

[Document Name] Scope of Claims [Claim 1]
A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising:
control maps provided in the engine control ECU, the control maps corresponding to a plurality of driving modes, respectively; and
means for selecting from the control maps the control map corresponding to driving mode information set up in the power train control ECU,
wherein the engine control ECU is controlled according to control information obtained by searching the selected control map. [Claim 2]
A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel,
wherein each of the engine control ECU and the power train control ECU has a plurality of control parameter output means applicable respectively to a plurality of vehicle driving modes,
the vehicle control system comprising means for selecting one control parameter output means both from the plurality of control parameter output means provided in the engine control ECU and one from the plurality of control parameter output means

provided in the power train control ECU according to the vehicle driving mode selected. [Claim 3]
A vehicle control system having an engine control ECU for controlling an engine and a power train control ECU for controlling a continuously variable transmission to change a speed of rotation of the engine and to transmit the rotation of the engine to a driving wheel, the vehicle control system comprising:
an actuator for adjusting a transmission ratio of the continuously variable transmission; and
a mode switch for selecting a driving mode of a vehicle,
the power train ECU comprising: target engine revolution number output means for outputting an engine revolution number corresponding to the driving mode; and a driver for supplying the actuator with a drive instruction to converge an actual revolution number of the engine on the target engine revolution number,
the engine control ECU comprising: a plurality of ignition timing output means for outputting ignition timing depending on the driving mode of the vehicle; a plurality of injection time output means for outputting a fuel injection time depending on the driving mode of the vehicle; an ignition driver for supplying a drive signal to an ignition plug according to the ignition timing; and an injection valve driver for supplying a drive signal to a fuel injection valve according to the fuel injection time. [Claim 4]
A control system for a belt-type continuously variable transmission installed in a vehicle, comprising:

means for detecting a throttle opening degree;
means for detecting a speed of the vehicle;
means for detecting an engine revolution number;
an actuator which changes transmission ratios;
target value outputting means for outputting a target engine revolution number as a function of the throttle opening degree and a vehicle speed, the target engine revolution number being larger as the throttle opening degree is larger;
transmission characteristic determining means for determining a driving direction and a driving speed of the actuator on the bases of the target engine revolution number and an actual engine revolution number;
means for outputting a throttle opening degree variation judgment value in accordance with the vehicle speed;
throttle opening degree variation judging means for judging whether a throttle opening degree variation every predetermined process cycle is larger than the throttle opening degree variation judgment value;
adding means for adding, if the throttle opening degree variation is larger than the throttle opening degree variation judgment value, a first throttle opening degree variation additional value to a throttle opening degree intended to be inputted to the target value outputting means, the adding means for adding, if the throttle opening degree variation is smaller than the throttle opening degree variation judgment value, a second throttle opening degree variation additional value to a throttle opening degree intended to be inputted to the target value outputting means, the second throttle opening degree variation additional value being larger than the first throttle opening degree variation additional value.

Documents:

1207-CHE-2006 CORRESPONDENCE OTHERS.pdf

1207-CHE-2006 CORRESPONDENCE PO.pdf

1207-CHE-2006 DESCRIPTION (COMPLETE) GRANTED.pdf

1207-CHE-2006 FORM-3.pdf

1207-CHE-2006 PETITIONS.pdf

1207-che-2006-abstract.jpg

1207-che-2006-abstract.pdf

1207-che-2006-claims.pdf

1207-che-2006-correspondence-others.pdf

1207-che-2006-description-complete.pdf

1207-che-2006-drawings.pdf

1207-che-2006-form 1.pdf

1207-che-2006-form 18.pdf

1207-che-2006-form 26.pdf

1207-che-2006-form 3.pdf

1207-che-2006-form 5.pdf

1207-che-2006-prority document.pdf

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Patent Number

235239

Indian Patent Application Number

1207/CHE/2006

PG Journal Number

29/2009

Publication Date

17-Jul-2009

Grant Date

26-Jun-2009

Date of Filing

10-Jul-2006

Name of Patentee

HONDA MOTOR CO.,LTD,

Applicant Address

1-1,MINAMI-AOYAMA 2-CHOME,MINATO-KU, TOKYO 107-8556

Inventors:

#	Inventor's Name	Inventor's Address
1	MATSUDAIRA, NAOTADA,	C/O HONDA R&D CO.,LTD, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA 351-0193.
2	OSAWA,TOSHIFUMI	C/O HONDA R& D CO,LTD, 4-1, CHUO, 1-CHOME, WAKO-SHI, SAITAMA,351-0193,
3	KOJIMA, MITSURU	C/O HONDA R & D,CO,LTD,4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA 351-0193
4	ASUMI, MICHIO	C/O HONDA R & D,CO,LTD,4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA 351-0193

PCT International Classification Number

B60K41/12

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2005-201475	2005-07-11	Japan
2	2005-205496	2005-07-14	Japan