Title of Invention

METHOD FOR TRANSMITTING A CONTROL SIGNAL TO A VEHICLE AND A RECEIVER DEVICE FOR RECEIVING THE CONTROL SIGNAL.

Abstract

TITLE: METHOD FOR TRANSMITTING A CONTROL SIGNAL TO A VEHICLE AND A RECEIVER DEVICE FOR RECEIVING THE CONTROL SIGNAL. The invention relates, inter alia, to a method for transmitting a control signal (Is) to a vehicle which is driven using an electrical drive current which is fed into a traction current conductor at a drive current feed point, said vehicle being electically connected to the traction current conductor by means of a drive current collector, in such a position that the drive current feed point, a line section, in which method current conductor and the control signal is received at the vehicle end using a current sensor, which is inductively coupled to the traction current conductor. In order to ensure that the transmission of the control signal is very largely unaffected by interference frequency componens contained in the drive current, according tot he invention only one current sensor which is located outside the line section, is used to receive the control signal (Is).

Full Text

Description Method for transmitting a control signal to a vehicle and a receiver device for receiving the control signal The invention relates to a method for transmitting a control signal to a vehicle which is driven using an electrical drive current which is fed into a traction current conductor at a drive current feed point, said vehicle being electrically connected to the traction current conductor by means of a drive current collector, in such a position that the drive current collector forms, together with the drive current feed point, a line section, in which method the control signal is fed into the traction current conductor and the control signal is received at the vehicle end using a current sensor which is inductively coupled to the traction current conductor. Such a method is known from the German laid-open application 1 405 691. In this previously known method, a control signal is fed, with commands or information for a rail vehicle, from a fixed command point into a contact wire as a traction current conductor; the electrical return flow of the control signal is ensured by the running rails and by suction circuits which are connected to the running rails and to the contact wire. The suction circuits are series resonant circuits which have low impedance for the control signals and high impedance for a drive current which is also transmitted via the contact wire. The drive current is used to drive the rail vehicle and is fed into the contact wire at a drive current feed point. The rail vehicle has a drive current collector via which the drive current flows into the rail vehicle. A line section is therefore formed by the drive current feed point and the position of the drive current collector. In order to receive the control signal, the rail vehicle is equipped with two current sensors, in the form of two coils, which are coupled inductively to the contact wire; one of the two current sensors is mounted at one end of the vehicle and the other of the two current sensors is mounted at the other end of the vehicle. As is also apparent from the laid-open application, both current sensors are used to receive the current signal. The invention is based on the object of developing a method of the type mentioned at the beginning to the effect that the transmission of the control signal to the vehicle is very largely unaffected by interference frequency components contained in the drive current. This object is achieved according to the invention by using only one current sensor, which is located outside the line section, to receive the control signal. A significant advantage of the method according to the invention is that only one current sensor, which is located outside the line section, is used to receive the control signal; this is because using just one current sensor located outside the line section ensures that the control signal is received without interference. This fact can be explained as follows: during the transmission of the drive current from the drive current feed point to the drive current collector, sparks are occasionally formed or arcs generated by the drive current collector, causing high-frequency interference currents to be generated in the traction current conductor; these interference currents flow from the drive current feed point to the drive current collector of the vehicle and subsequently back to the drive current feed point via a return conductor, for example rails in rail-bound vehicles, with the result that these high-frequency interference currents are therefore applied to the line section which is bounded by the drive current feed point and the drive current collector. Therefore, if only one current sensor, which is located outside this line section, is used to receive the control signal, only the control signal which is not subject to interference is measured with the current sensor, and thus say neither the drive current nor the high-frequency interference currents contained in the drive current are measured. In order to ensure reliable inductive transmission of the control signal to the vehicle, a sufficiently large control signal current must be able to flow through the traction current conductor; this can be achieved according to a development of the method according to the invention by virtue of the fact that the control signal is transmitted from the traction current conductor to a return conductor of the control signal via a low-impedance suction filter for the control signal, which suction filter is arranged on the vehicle in such a way that the current sensor is located spatially between a control signal feed point of the traction current conductor and the suction filter. Vehicle-mounted suction filters which have low impedance for control signals are known per se from German patent 538 650. In order to ensure reliable inductive transmission, there is provision according to another development of the method according to the invention for the control signal to be transmitted from the traction current conductor to a return conductor of the control signal via a low-impedance suction filter for the control signal, which suction filter is fixedly arranged, in the case of rail vehicles, for example, on the track, in such a way that the current sensor is located spatially between a control signal feed point of the traction current conductor and the suction filter. The control signal can be particularly reliably transmitted to the vehicle if a binary coded signal is transmitted as control signal because binary coded signals make it possible to use additional check bits with which the received control signal can be tested in the vehicle for transmission errors. The control signal can be transmitted particularly easily, and thus advantageously, if an FSK (Frequency Shift Keying) signal, an OFDM (Orthogonal Frequency Division Multiplexing) signal or a spread spectrum signal is transmitted as the binary coded signal. A further advantageous embodiment of the method according to the invention is described in claim 6. The advantages of this embodiment are described in conjunction with the device according to the invention as claimed in claim 7. The invention also relates to a receiver device for receiving a control signal for a vehicle which has a drive current collector and two current sensors which are arranged on each side of the drive current collector. Such a device can also be inferred from the laid-open application mentioned at the beginning. A receiver device which is developed further on the basis of the previously known device in accordance with the aforementioned laid-open application to the effect that the transmission of a control signal is not affected by interference frequency components contained in the drive current is proposed according to the invention with claim 7. This receiver device according to the invention is distinguished in that it has a switching device which, for the reception of the control signal, selects that current sensor of the two current sensors which has the lower reception power. The significant advantage of the arrangement according to the invention consists in the fact that the switching device ensures that, while the vehicle is operated, the control signal is always received exclusively with the current sensor which is located outside the line section determined by the drive current feed point and the position of the drive current collector; this is because the switching device always activates that current sensor which has a lower overall reception power, to receive the control signal. As has already been explained in conjunction with the method according to the invention, both the control signal current and the drive current with its high-frequency interference components flow via the part of the traction current conductor located in the line section, with the result that the current sensor located in the line section must have a significantly greater overall reception power than that current sensor which is located outside this line section, because only the control signal current flows in the traction current conductor outside the line section. The switching device in the receiver device according to the invention therefore selects that current sensor with which the receiving signal can be received, more reliably because the selected current sensor does not have its own drive current applied to it, and therefore does not have the interference current contained in its own drive current applied to it. In order to explain the invention,an accompanying figure shows an exemplary embodiment of an arrangement for carrying out the method according to the invention and an exemplary embodiment for the receiver device according to the invention. The figure shows a rail vehicle 5 which is connected with a drive current collector 10 to a contact wire 15 as traction current conductor. A drive voltage Ua is applied to the contact wire 15 at a drive current feed point 20,1 by means of which drive voltage Ua a drive current la flows through the contact wire 15, the drive current collector 10 and a drive motor 21 of the rail vehicle 5. The return flow of the drive current la is ensured by rails 22 on which the rail vehicle 5 travels. The drive current feed point 20 and the drive current collector 10 or its position define a line section 25. A control signal in the form of a control signal current Is is fed into the contact wire 15 at a control signal feed point 30. The control signal current Is passes to the rail vehicle 5 and to a suction filter 35 which is formed by a series resonant circuit with a capacitor C and an inductor L, and which, together with the control signal feed point 30, defines a further line section 40. The return flow of the control signal or the control signal current Is is ensured by the rails 22. In this further line section 40, the control signal or the control signal current Is is therefore transmitted via the contact wire 15. The rail vehicle 5 has two current sensors 45 and 50 in the form of antennas which are embodied, for example, as coils and which are coupled inductively to the contact wire 15 at a distance of, for example, approximately 0.5 m. One of the two current sensors 45 is located in the one line section 25 while the other of the two current sensors 50 is located outside this line section 25. The two current sensors 45 and 50 are used to determine current measuring values which indicate the current flowing through the contact wire 15 at the respective current sensor point. The current measuring value Ml of the current sensor 45 therefore gives the current Ia+Is in the contact wire 15, and the current measuring value M2 gives the current measuring value Is in the contact wire 15; it is in fact assumed that the drive motor 21 has such a high impedance for the control current Is, whether independently or as a result of appropriately embodied operating current filter circuits which are assigned to the drive motor 21, that the control current Is flows away through the drive motor 21 to a negligibly small degree. The two current measuring values Ml and M2 are each fed to an input of a switching device 55, downstream of which a control signal evaluation device 60 is arranged on the output side. The switching device 55 and the control signal evaluation device 60 and the two current sensors 45 and 50 form a receiver device 65 for the rail vehicle 5, for receiving the control signal and the control current Is. The two current measuring values Ml and M2 are compared in the switching device 55 in terms of their reception power. In this process it is ensured that the reception power PI of the current sensor 45 is significantly greater than the reception power P2 of the current sensor 50; this is because the following applies: PI - (la + Is)2 » P2 ~ Is2 because the drive current la is significantly greater than the control signal current Is. The switching device 55 then selects the current sensor 50 to receive the control current Is because the current measuring value M2 of the current sensor 50 is free of the drive current la, and thus free of high-frequency interference currents contained in the drive current la, and transmits the current measuring value M2 to the control signal evaluation device 60 in which the control signal or the control signal current Is is evaluated. In the arrangement according to the figure, the suction filter 35 is mounted on the line between the contact wire 15 and the rails 22. Instead of this, it is also possible to mount the suction filter 35 on the rail vehicle. The electrical contact with the contact wire 15 is to be ensured in such a case by, for example, an additional current collector which is to be arranged on the vehicle in such a way that the current sensor 50 which is suitable for receiving the control signal or control current Is is located spatially between the control signal feed point 30 and the suction filter. In the exemplary embodiment described in conjunction with the figure, the current sensors 45 and 50 are provided, and the current measuring values Ml and M2 for the switching device 5 5 are measured with said current sensors 45 and 50; with an appropriately configured switching device 55 it is also possible to use, instead of the current sensors 45 and 50, current sensors of some other type, namely ones with which in each case current measuring variables or voltage measuring variables which are proportional to the current flowing at the respective point in the contact wire 15 are formed for the switching device 55. In summary, therefore, a method for transmitting a control signal to an electrically driven vehicle is thus described in which the transmission of the control signal to the vehicle is unaffected by interference frequency components contained in the drive current of this vehicle. It is then possible to transmit, for example, a binary coded signal, preferably an FSK (Frequency Shift Keying) signal, an OFDM (Orthogonal Frequency Division Multiplexing) signal or a spread spectrum signal as the control signal or control current Is. The method according to the invention can be advantageously used in rail vehicles, trolleybuses, cable railroads, suspended railroads or other vehicles which are driven electrically via a traction current conductor. The traction current conductor can be a contact wire (for example overhead line in the case of rail vehicles) or as a current rail or the like. WE CLAIM: 1. A method for transmitting a control signal (Is) to a vehicle (5) which is driven using an electrical drive current CIa) for a drive motor (21), which is fed into a traction current conductor (15) at a drive current feed point (20), said vehicle being electrically connected to the traction current conductor (15) by means of a drive current collector (10), in such a position that the drive current collector (10) fonts, together with the drive current feed point (20), a line section (25) comprising the steps of: - feeding the control signal (Is) into the traction current conductor (15), the drive motor (21) for the control signal (Is) being of such % high impedance that the control signal (Is) flows away through the drive motor (21) to a negligibly small degree, - receiving the control signal (Is) at the vehicle end using a current sensor (45, 50) which is inductively coupled to the traction current conductor (15), and - using only one current sensor (50), which is located outside the line section (25), to receive the control signal (Is). 2. The method as claimed in claim 1, further comprising : - transmitting the control signal from the traction current conductor to a return conductor of the control signal via a low-impedance suction filter for the control signal (Is), which suction filter is arranged on the vehicle in such a way - that the current sensor is located spatially between a control signal feed point of the traction current conductor and the suction filter. 3. The method as claimed in claim 1, further comprising s - transmitting the control signal (Is) from the traction current conductor (15) to a return conductor (22) of the control signal (Is) via a low-impedance suction filter (35) for the control signal (Is), which suction filter (35) is fixedly arranged in such a way - that the current sensor (50) is located spatially between a control signal feed point (30) of the traction current conductor (15) and the suction filter (35). 4. The method as claimed in one of the preceding claims wherein a binary coded signal is transmitted as the control signal (Is). 5. The method as claimed in claim 4, wherein an FBK (Frequency Shift Keying) signal, an OFDM (Orthogonal Frequency Division Multiplexing) Signal or a spread spectrum signal is transmitted as the binary coded signal (Is). 6. The method as claimed in one of the preceding claims, further comprising : - measuring the current in the traction current conductor (15) using two current sensors (45,50) which are arranged on each side of the drive current collector (10), and - selecting the current measuring value (Ms} of that current sensor (50) which, of the two current sensors (45, 50) has the lower reception power to receive the control signal (Is). 7. A receiver device (65) for a vehicle (5) which has a drive current collector (10) and a drive Motor (21), for receiving a control signal (is) which is transmitted to the vehicle (5) via a traction current conductor (15) and for which the drive motor (21) has such a high impedance that the control signal (Is) flows away through the drive motor (21) to a negligibly small degree, - the receiver device (65) having : two current sensors (45,50) which are coupled to the traction current conductor (5), and one of which is arranged ahead of the drive current collector (10) in the direction of travel and one is arranged behind the drive current collector (10) in the direction of travel, and - a switching device (55) which is connected to the two current sensors (45,50) and selects that current sensor (50) whcih, of the two current sensors (45,50) has the lower overall reception power to receive the control signal (Is). Method for transmitting a control signal to a vehicle and a receiver device for receiving the control signal The invention relates, inter alia, to a method for transmitting a control signal (Is) to a vehicle (5) which is driven using an electrical drive current (la) which is fed into a traction current conductor (15) at a drive current feed point (20), said vehicle (5) being electrically connected to the traction current conductor (15) by means of a drive current collector (10), in such a position that the drive current collector (10) forms, together with the drive current feed point (20), a line section (25), in which method the control signal (Is) is fed into the traction current conductor (15) and the control signal (Is) is received at the vehicle end using a current sensor (45, 50) which is inductively coupled to the traction current conductor (15). In order to ensure that the transmission of the control signal is very largely unaffected by interference frequency components contained in the drive current, according to the invention only one current sensor (50) , which is located outside the line section (25) , is used to receive the control signal (Is).

Documents:

IN-PCT-2001-850-KOL-(03-09-2012)-FORM-27.pdf

IN-PCT-2001-850-KOL-CORRESPONDENCE.pdf

IN-PCT-2001-850-KOL-FORM 27.pdf

IN-PCT-2001-850-KOL-FORM-27.pdf

in-pct-2001-850-kol-granted-abstract.pdf

in-pct-2001-850-kol-granted-claims.pdf

in-pct-2001-850-kol-granted-correspondence.pdf

in-pct-2001-850-kol-granted-description (complete).pdf

in-pct-2001-850-kol-granted-drawings.pdf

in-pct-2001-850-kol-granted-examination report.pdf

in-pct-2001-850-kol-granted-form 1.pdf

in-pct-2001-850-kol-granted-form 18.pdf

in-pct-2001-850-kol-granted-form 2.pdf

in-pct-2001-850-kol-granted-form 3.pdf

in-pct-2001-850-kol-granted-form 5.pdf

in-pct-2001-850-kol-granted-gpa.pdf

in-pct-2001-850-kol-granted-letter patent.pdf

in-pct-2001-850-kol-granted-priority document.pdf

in-pct-2001-850-kol-granted-reply to examination report.pdf

in-pct-2001-850-kol-granted-specification.pdf

in-pct-2001-850-kol-granted-translated copy of priority document.pdf

IN-PCT-2001-850-KOL-PA.pdf