Title of Invention	A SYSTEM AND A METHOD FOR SETTING THE SPEED OF A VEHICLE TO A MAXIMUM PERMISSIBLE VALUE
Abstract	The invention relates to a system and method for setting the speed of a vehicle to a maximum permissible speed, comprising a limiting device (2) that, by means of engine intervention, limits the attainable speed of the vehicle to a maximum value, and comprising an information device (1) that, when the maximum permissible speed is modified during driving, induces the limiting device (2) to limit the vehicle speed to a modified maximum value. According to the invention, the information device (1) is a device for identifying the type of road currently being driven upon. The information device (1) reads the maximum permissible speed associated with the type of road currently being driven upon out of a memory device (7) and considers this maximum permissible speed as a modified maximum value.

Title of Invention

A SYSTEM AND A METHOD FOR SETTING THE SPEED OF A VEHICLE TO A MAXIMUM PERMISSIBLE VALUE

Abstract

The invention relates to a system and method for setting the speed of a vehicle to a maximum permissible speed, comprising a limiting device (2) that, by means of engine intervention, limits the attainable speed of the vehicle to a maximum value, and comprising an information device (1) that, when the maximum permissible speed is modified during driving, induces the limiting device (2) to limit the vehicle speed to a modified maximum value. According to the invention, the information device (1) is a device for identifying the type of road currently being driven upon. The information device (1) reads the maximum permissible speed associated with the type of road currently being driven upon out of a memory device (7) and considers this maximum permissible speed as a modified maximum value.

Full Text	PCT/EP2005/054561 - 1 - 2004P16808WOIN Description System and method for setting the speed of a vehicle to a maximum permissible speed The invention relates to a system and a method for setting the speed of a vehicle to a maximum permissible speed. The system comprises a limiting device which limits the attainable traveling speed of the vehicle to a maximum value by means of engine intervention, and an information device which prompts the limiting device to limit the traveling speed to a modified maximum value when the maximum permissible speed changes during driving. An apparatus of this type and an associated method are known from DE-197 12 722-A1, with an external transmission device emitting signals about the maximum permissible speed in accordance with the speed restrictions, which are indicated by road signs, on sections of road, for example freeway entrances or roadworks sites. In modern motor vehicles, limiting devices for limiting the attainable traveling speed are used in conjunction with cruise control devices, with the desired maximum speed being prespecified by the driver himself. Furthermore, in the case of heavy-goods vehicles and buses, there is a statutory requirement, starting from a specific vehicle weight, for a limiting device to be used, said limiting device ensuring that the statutory maximum speed applicable to the class of vehicle in question is complied with. One example of such a limiting device is the speed limier AGB II from Siemens VDO AG. In the known limiting devices, PCT/EP2005/054561 - 2 - 2004P16808WOIN the maximum value of the attainable traveling speed is permanently stored in a memory device, with the result that this maximum value applies for the entire drive mode of the vehicle and can be changed only at a garage. The object of the present invention is to improve the known systems and methods for limiting speed such that they can be used in a more flexible manner. This object is achieved with a system as claimed in claim 1 and a method as claimed in claim 11. In the system according to the invention, the information device is a device for identifying the type of road currently being driven on. The information device reads out the maximum permissible speed which is associated with the type of road currently being driven on from a memory device and takes said maximum permissible speed into account as a modified maximum value, that is to say the information device prompts the limiting device to limit the traveling speed to this modified maximum value. The method according to the invention comprises the steps of identifying the type of road currently being driven on, and reading out the maximum permissible speed which is associated with the type of road currently being driven on from a memory device and taking said maximum permissible speed into account as a modified maximum value. The system according to the invention and the method according to the invention can be used to match the attainable traveling speed of the vehicle to the respectively applicable statutory regulations on different types of road. In contrast, the known limiting device for heavy-goods vehicles PCT/EP2005/054561 - 3 - 2004P16808WOIN and buses can be used to comply with only a single prescribed maximum value which generally corresponds to the permitted maximum speed on freeways. However, statutory maximum values which differ from those on freeways apply on highways and expressways. Since the information device according to the invention identifies the type of road on which the vehicle is currently moving, the speed restrictions can also be correspondingly tracked. This provides shipping companies with the advantage, for example, that fewer speeding fines are incurred. In one preferred refinement, the information device distinguishes between a toll road and a toll-free road in the case of the type of road currently being driven on. Accordingly, the information device may directly be a toll- detection device which identifies whether the vehicle is currently located on a toll road or not, in order to ascertain the road-use charges to be paid. The toll-detection device is accordingly directly coupled to the limiting device. A different maximum permissible speed to that on toll-free roads can now apply on a toll road. This is particularly the case in toll systems in which tolls are levied only on freeways and at most also expressways. A correspondingly higher maximum value for the traveling speed can now be prescribed on these roads than on toll-free roads. On account of the higher attainable traveling speed on the toll roads and the resulting shorter transportation times, fewer commercial vehicles will switch to highways and side roads, with the result that the amount of traffic in adjacent areas can be reduced, which results in these areas needing to be redeveloped less often. PCT/EP2005/054561 - 4 - 2004P16808WOIN In a further refinement, the information device distinguishes between classes of road. By way of example, the navigation devices with integrated route planning which are presently known carry out such a distinguishing operation. In this case, the classes of road are taken from a road map and associated with the current position of the vehicle. Toll-detection devices can also be designed such that they make a finer distinction between the individual classes of road than previously, that is to say the toll-detection devices no longer only identify whether the vehicle is located on a freeway or not, but instead distinguish between different classes of road, that is to say freeway, expressway, highway, urban road etc. A different fee is then levied in a graded manner depending on the class of road. In accordance with this consideration, the information device distinguishes between toll roads with different toll fees in a further refinement. Coupling between a navigation or toll-detection device which identifies the current class of road and a limiting means accordingly enables the attainable traveling speed to be matched to the respective statutory maximum speed. This is advantageous particularly for drivers of commercial vehicles since they neither need to drive on the various roads more slowly than is permitted and therefore also do not unnecessarily create an obstacle to traffic, nor can they drive too fast, as a result of which fines are avoided. In a development of the invention, the information device ascertains a maximum permissible speed as a function of both the type of road currently being driven on and also an area currently being driven through. In this case, an area is to be understood as a part of a road network which is bounded by a closed polygon. In this case, the association between the area PCT/EP2005/054561 - 5 - 2004P16808WOIN being driven through, the type of road being driven on and the maximum permissible speed can, for example, be stored in the memory device as a three-dimensional parameter field. In a sub-embodiment, the area currently being driven through is determined by the borders of a country. An area could likewise be defined as a region or a combination of countries. The important factor here is that different maximum speeds apply for the same types of road among the individual areas, whereas identical regulations apply within an area. The flexibility of the speed-limiting means is increased by adapting to the maximum speeds which apply depending on the area, and this entails, amongst other things, time advantages for drivers of commercial vehicles. For example, different maximum speeds currently apply for identical classes of vehicle in different countries within the European Union. Drivers of commercial vehicles from Germany find it difficult when travelling through the Netherlands, for example, as they impede the flow of traffic since their maximum value for the traveling speed for freeways is set lower than in domestic commercial vehicles. Disadvantages of this type are avoided by adapting the speed depending on the area, and traffic flow is improved. In a further refinement, the information device ascertains the area actually being driven through on the basis of the current position of the vehicle and a road map. Since both toll- detection and navigation devices know the current position of the vehicle and have a road map available, only one further software module is required, which software module checks the area boundaries within which the position of the vehicle is currently located. PCT/EP2005/054561 - 6 - 2004P16808WOIN In another refinement, the information device is provided with a wireless reception unit which receives an area signal, which is transmitted by an external transmission unit, for identifying the area currently being driven through. One example of such a refinement would be a mobile radio unit, for example a GSM unit, which transmits a country identifier. Mobile radio units of this type are sometimes provided as standard in toll systems in order to allow communication with a central station for interchanging toll-related data. Depending on the current mobile radio network in which the vehicle is moving, a corresponding country code is emitted by GSM, it being possible for the information device to use this country code in order to access the two-dimensional parameter field, which is associated with this country, of the types of road with an associated maximum speed. Ascertaining the area currently being driven through within the information device by checking whether area borders have been crossed is dispensed with here. A further embodiment of the invention provides that the information device is provided with a wireless reception unit which receives the maximum permissible speeds which are transmitted by an external transmission unit with a respective type of road, and stores said maximum permissible speeds in the memory device. The information device therefore receives an always currently applicable two-dimensional parameter field from the external transmission unit. If, for example, the maximum permissible speeds change due to new legislation, the data in the information device can be simply updated without a visit to a garage being required. A new parameter field can be transmitted either once, for example after the vehicle is started, or else repeatedly, PCT/EP2005/054561 - 7 - 2004P16808WOIN particularly as a function of the area currently being driven through. The latter reduces the memory requirement in the information device. By way of example, an external mobile radio transmitter can identify the position of a toll-detection device which is equipped with a mobile radio unit on the basis of the mobile radio cell currently being used, draw conclusions about a new area being driven through from this, and correspondingly prompt the transmission of a new parameter field. The information device can likewise transmit the current position to the external transmitter or even forward the automatically identified current area, after which the external transmitter transmits the maximum speeds applicable in the area. The invention is explained in greater detail below with reference to an exemplary embodiment and the drawing, in which: figure 1 shows a system for setting the speed of a commercial vehicle to a maximum permissible speed. The system for setting the speed of a commercial vehicle to a statutorily prescribed maximum speed, which system is illustrated in figure 1, contains an information device 1 in the form of a toll-detection device and a speed controller which is connected to the information device 1 and acts as a limiting device 2. The speed controller intervenes in the control system of an engine 3 of a commercial vehicle (not illustrated) to the effect that it limits the speed which can be attained by the vehicle to a maximum value using the engine control variables, such as ignition advance angle and/or throttle valve angle or fuel injection quantity. The maximum value for the traveling speed is stored in a memory unit 4 of the limiting PCT/EP2005/054561 - 8 - 2004P16808WOIN device 2. The information device 1 contains a position- detection unit 5 for determining the current position of the commercial vehicle, and a computer unit 6, which is connected to the position-detection unit 5, for determining the type of road currently being driven on on the basis of comparison of the current position of the vehicle with the coordinates of the roads on a road map. The road map is stored in a memory unit 7 which is connected to the computer unit 6. After the commercial vehicle is started, the information device 1 continuously ascertains the type of road currently being driven on. Depending on the current type of road, said information device determines the currently applicable maximum speed on the basis of a two-dimensional parameter field which is stored in the memory unit 7 and contains maximum permissible speeds associated with the types of road. Said information device emits this currently applicable maximum speed as a currently applicable maximum value to the limiting device 2 which stores the maximum value in the memory device 4 and takes said maximum value into account during the next engine interventions, that is to say the limiting device 2 correspondingly adapts the values for the engine control variables to be set as a maximum. The computer unit 6 of the information device 1 is furthermore equipped with a wireless reception unit 8 which, in this example, is a GSM unit. The reception unit 8 receives signals from an external transmission unit 9 during driving. An associated country identifier is transmitted to the reception unit 8 by the transmission unit 9 in accordance with the current position of the vehicle within the range of a respective GSM cell. The information device uses the country identifier to ascertain which of the two-dimensional parameter fields stored in the memory device 7 is applicable in the country. The two dimensions, type of road PCT/EP2005/054561 - 9 - 2004P16808WOIN and maximum speed, therefore form a kind of three-dimensional parameter field in conjunction with the dimension country, from which parameter field a two-dimensional parameter field comprising types of road and associated maximum speeds is selected depending on the current country identifier. PCT/2P2005/054561 - 10 - 2004P16808WOIN Patent claims 1. A system for setting the speed of a vehicle to a maximum permissible speed, comprising a limiting device (2) which limits the attainable traveling speed of the vehicle to a maximum value by means of engine intervention, and an information device (1) which prompts the limiting device (2) to limit the traveling speed to a modified maximum value when the maximum permissible speed changes during driving, characterized in that the information device (1) is a device for identifying the type of road currently being driven on, and in that the information device (1) reads out the maximum permissible speed which is associated with the type of road currently being driven on from a memory device (7) and takes said maximum permissible speed into account as a modified maximum value. 2. The system as claimed in claim 1, characterized in that the information device (1) distinguishes between a toll road and a toll-free road in the case of the type of road currently being driven on. 3. The system as claimed in either of claims 1 and 2, characterized in that the information device (1) distinguishes between classes of road in the case of the type of road currently being driven on. 4. The system as claimed in one of the preceding claims, characterized in that the information device (1) PCT/EP2005/054561 - 11 - 2004P16808WOIN distinguishes between toll roads with different toll fees in the case of the type of road currently being driven on. 5. The system as claimed in one of the preceding claims, characterized in that the information device (1) ascertains a maximum permissible speed as a function of both the type of road currently being driven on and also an area currently being driven through. 6. The system as claimed in claim 5, characterized in that the area currently being driven through is determined by the borders of a country. 7. The system as claimed in either of claims 5 and 6, characterized in that the information device (1) itself ascertains the area currently being driven through on the basis of the current position of the vehicle and a road map. 8. The system as claimed in either of claims 5 and 6, characterized in that the information device (1) is provided with a wireless reception unit (8) which receives an area signal, which is transmitted by an external transmission unit (9), for identifying the area currently being driven through. 9. The system as claimed in one of the preceding claims 1 to 6, characterized in that the information device (1) is provided with a wireless reception unit (8) which receives the maximum permissible speeds which are transmitted by an external transmission unit (9) with a respective type of road, PCT/EP2005/054561 - 12 - 2004P16808WOIN and stores said maximum permissible speeds in the memory device (7). 10. The system as claimed in claims 5 and 7, characterized in that the external transmission unit (9) carries out the transmission operation when the vehicle crosses or has just crossed an area boundary. 11. A method for setting the speed of a vehicle to a maximum permissible speed, in which method the attainable traveling speed of the vehicle is limited to a maximum value by means of engine intervention, and the traveling speed is limited to a modified maximum value when the maximum permissible speed changes during driving, characterized in that the type of road currently being driven on is identified, and in that the maximum permissible speed which is associated with the type of road currently being driven on is read out from a memory device (7) and taken into account as a modified maximum value. The invention relates to a system and method for setting the speed of a vehicle to a maximum permissible speed, comprising a limiting device (2) that, by means of engine intervention, limits the attainable speed of the vehicle to a maximum value, and comprising an information device (1) that, when the maximum permissible speed is modified during driving, induces the limiting device (2) to limit the vehicle speed to a modified maximum value. According to the invention, the information device (1) is a device for identifying the type of road currently being driven upon. The information device (1) reads the maximum permissible speed associated with the type of road currently being driven upon out of a memory device (7) and considers this maximum permissible speed as a modified maximum value.

Full Text

PCT/EP2005/054561 - 1 -
2004P16808WOIN
Description
System and method for setting the speed of a vehicle to a
maximum permissible speed
The invention relates to a system and a method for setting the
speed of a vehicle to a maximum permissible speed. The system
comprises a limiting device which limits the attainable
traveling speed of the vehicle to a maximum value by means of
engine intervention, and an information device which prompts
the limiting device to limit the traveling speed to a modified
maximum value when the maximum permissible speed changes during
driving.
An apparatus of this type and an associated method are known
from DE-197 12 722-A1, with an external transmission device
emitting signals about the maximum permissible speed in
accordance with the speed restrictions, which are indicated by
road signs, on sections of road, for example freeway entrances
or roadworks sites.
In modern motor vehicles, limiting devices for limiting the
attainable traveling speed are used in conjunction with cruise
control devices, with the desired maximum speed being
prespecified by the driver himself. Furthermore, in the case of
heavy-goods vehicles and buses, there is a statutory
requirement, starting from a specific vehicle weight, for a
limiting device to be used, said limiting device ensuring that
the statutory maximum speed applicable to the class of vehicle
in question is complied with. One example of such a limiting
device is the speed limier AGB II from Siemens VDO AG. In the
known limiting devices,

PCT/EP2005/054561 - 2 -
2004P16808WOIN
the maximum value of the attainable traveling speed is
permanently stored in a memory device, with the result that
this maximum value applies for the entire drive mode of the
vehicle and can be changed only at a garage.
The object of the present invention is to improve the known
systems and methods for limiting speed such that they can be
used in a more flexible manner.
This object is achieved with a system as claimed in claim 1 and
a method as claimed in claim 11.
In the system according to the invention, the information
device is a device for identifying the type of road currently
being driven on. The information device reads out the maximum
permissible speed which is associated with the type of road
currently being driven on from a memory device and takes said
maximum permissible speed into account as a modified maximum
value, that is to say the information device prompts the
limiting device to limit the traveling speed to this modified
maximum value.
The method according to the invention comprises the steps of
identifying the type of road currently being driven on, and
reading out the maximum permissible speed which is associated
with the type of road currently being driven on from a memory
device and taking said maximum permissible speed into account
as a modified maximum value.
The system according to the invention and the method according
to the invention can be used to match the attainable traveling
speed of the vehicle to the respectively applicable statutory
regulations on different types of road. In contrast, the known
limiting device for heavy-goods vehicles

PCT/EP2005/054561 - 3 -
2004P16808WOIN
and buses can be used to comply with only a single prescribed
maximum value which generally corresponds to the permitted
maximum speed on freeways. However, statutory maximum values
which differ from those on freeways apply on highways and
expressways. Since the information device according to the
invention identifies the type of road on which the vehicle is
currently moving, the speed restrictions can also be
correspondingly tracked. This provides shipping companies with
the advantage, for example, that fewer speeding fines are
incurred.
In one preferred refinement, the information device
distinguishes between a toll road and a toll-free road in the
case of the type of road currently being driven on.
Accordingly, the information device may directly be a toll-
detection device which identifies whether the vehicle is
currently located on a toll road or not, in order to ascertain
the road-use charges to be paid. The toll-detection device is
accordingly directly coupled to the limiting device. A
different maximum permissible speed to that on toll-free roads
can now apply on a toll road. This is particularly the case in
toll systems in which tolls are levied only on freeways and at
most also expressways. A correspondingly higher maximum value
for the traveling speed can now be prescribed on these roads
than on toll-free roads. On account of the higher attainable
traveling speed on the toll roads and the resulting shorter
transportation times, fewer commercial vehicles will switch to
highways and side roads, with the result that the amount of
traffic in adjacent areas can be reduced, which results in
these areas needing to be redeveloped less often.

PCT/EP2005/054561 - 4 -
2004P16808WOIN
In a further refinement, the information device distinguishes
between classes of road. By way of example, the navigation
devices with integrated route planning which are presently
known carry out such a distinguishing operation. In this case,
the classes of road are taken from a road map and associated
with the current position of the vehicle. Toll-detection
devices can also be designed such that they make a finer
distinction between the individual classes of road than
previously, that is to say the toll-detection devices no longer
only identify whether the vehicle is located on a freeway or
not, but instead distinguish between different classes of road,
that is to say freeway, expressway, highway, urban road etc. A
different fee is then levied in a graded manner depending on
the class of road. In accordance with this consideration, the
information device distinguishes between toll roads with
different toll fees in a further refinement. Coupling between a
navigation or toll-detection device which identifies the
current class of road and a limiting means accordingly enables
the attainable traveling speed to be matched to the respective
statutory maximum speed. This is advantageous particularly for
drivers of commercial vehicles since they neither need to drive
on the various roads more slowly than is permitted and
therefore also do not unnecessarily create an obstacle to
traffic, nor can they drive too fast, as a result of which
fines are avoided.
In a development of the invention, the information device
ascertains a maximum permissible speed as a function of both
the type of road currently being driven on and also an area
currently being driven through. In this case, an area is to be
understood as a part of a road network which is bounded by a
closed polygon. In this case, the association between the area

PCT/EP2005/054561 - 5 -
2004P16808WOIN
being driven through, the type of road being driven on and the
maximum permissible speed can, for example, be stored in the
memory device as a three-dimensional parameter field.
In a sub-embodiment, the area currently being driven through is
determined by the borders of a country. An area could likewise
be defined as a region or a combination of countries. The
important factor here is that different maximum speeds apply
for the same types of road among the individual areas, whereas
identical regulations apply within an area. The flexibility of
the speed-limiting means is increased by adapting to the
maximum speeds which apply depending on the area, and this
entails, amongst other things, time advantages for drivers of
commercial vehicles. For example, different maximum speeds
currently apply for identical classes of vehicle in different
countries within the European Union. Drivers of commercial
vehicles from Germany find it difficult when travelling through
the Netherlands, for example, as they impede the flow of
traffic since their maximum value for the traveling speed for
freeways is set lower than in domestic commercial vehicles.
Disadvantages of this type are avoided by adapting the speed
depending on the area, and traffic flow is improved.
In a further refinement, the information device ascertains the
area actually being driven through on the basis of the current
position of the vehicle and a road map. Since both toll-
detection and navigation devices know the current position of
the vehicle and have a road map available, only one further
software module is required, which software module checks the
area boundaries within which the position of the vehicle is
currently located.

PCT/EP2005/054561 - 6 -
2004P16808WOIN
In another refinement, the information device is provided with
a wireless reception unit which receives an area signal, which
is transmitted by an external transmission unit, for
identifying the area currently being driven through. One
example of such a refinement would be a mobile radio unit, for
example a GSM unit, which transmits a country identifier.
Mobile radio units of this type are sometimes provided as
standard in toll systems in order to allow communication with a
central station for interchanging toll-related data. Depending
on the current mobile radio network in which the vehicle is
moving, a corresponding country code is emitted by GSM, it
being possible for the information device to use this country
code in order to access the two-dimensional parameter field,
which is associated with this country, of the types of road
with an associated maximum speed. Ascertaining the area
currently being driven through within the information device by
checking whether area borders have been crossed is dispensed
with here.
A further embodiment of the invention provides that the
information device is provided with a wireless reception unit
which receives the maximum permissible speeds which are
transmitted by an external transmission unit with a respective
type of road, and stores said maximum permissible speeds in the
memory device. The information device therefore receives an
always currently applicable two-dimensional parameter field
from the external transmission unit. If, for example, the
maximum permissible speeds change due to new legislation, the
data in the information device can be simply updated without a
visit to a garage being required. A new parameter field can be
transmitted either once, for example after the vehicle is
started, or else repeatedly,

PCT/EP2005/054561 - 7 -
2004P16808WOIN
particularly as a function of the area currently being driven
through. The latter reduces the memory requirement in the
information device. By way of example, an external mobile radio
transmitter can identify the position of a toll-detection
device which is equipped with a mobile radio unit on the basis
of the mobile radio cell currently being used, draw conclusions
about a new area being driven through from this, and
correspondingly prompt the transmission of a new parameter
field. The information device can likewise transmit the current
position to the external transmitter or even forward the
automatically identified current area, after which the external
transmitter transmits the maximum speeds applicable in the
area.
The invention is explained in greater detail below with
reference to an exemplary embodiment and the drawing, in which:
figure 1 shows a system for setting the speed of a commercial
vehicle to a maximum permissible speed.
The system for setting the speed of a commercial vehicle to a
statutorily prescribed maximum speed, which system is
illustrated in figure 1, contains an information device 1 in
the form of a toll-detection device and a speed controller
which is connected to the information device 1 and acts as a
limiting device 2. The speed controller intervenes in the
control system of an engine 3 of a commercial vehicle (not
illustrated) to the effect that it limits the speed which can
be attained by the vehicle to a maximum value using the engine
control variables, such as ignition advance angle and/or
throttle valve angle or fuel injection quantity. The maximum
value for the traveling speed is stored in a memory unit 4 of
the limiting

PCT/EP2005/054561 - 8 -
2004P16808WOIN
device 2. The information device 1 contains a position-
detection unit 5 for determining the current position of the
commercial vehicle, and a computer unit 6, which is connected
to the position-detection unit 5, for determining the type of
road currently being driven on on the basis of comparison of
the current position of the vehicle with the coordinates of the
roads on a road map. The road map is stored in a memory unit 7
which is connected to the computer unit 6.
After the commercial vehicle is started, the information device
1 continuously ascertains the type of road currently being
driven on. Depending on the current type of road, said
information device determines the currently applicable maximum
speed on the basis of a two-dimensional parameter field which
is stored in the memory unit 7 and contains maximum permissible
speeds associated with the types of road. Said information
device emits this currently applicable maximum speed as a
currently applicable maximum value to the limiting device 2
which stores the maximum value in the memory device 4 and takes
said maximum value into account during the next engine
interventions, that is to say the limiting device 2
correspondingly adapts the values for the engine control
variables to be set as a maximum.
The computer unit 6 of the information device 1 is furthermore
equipped with a wireless reception unit 8 which, in this
example, is a GSM unit. The reception unit 8 receives signals
from an external transmission unit 9 during driving. An
associated country identifier is transmitted to the reception
unit 8 by the transmission unit 9 in accordance with the
current position of the vehicle within the range of a
respective GSM cell. The information device uses the country
identifier to ascertain which of the two-dimensional parameter
fields stored in the memory device 7 is applicable in the
country. The two dimensions, type of road

PCT/EP2005/054561 - 9 -
2004P16808WOIN
and maximum speed, therefore form a kind of three-dimensional
parameter field in conjunction with the dimension country, from
which parameter field a two-dimensional parameter field
comprising types of road and associated maximum speeds is
selected depending on the current country identifier.

PCT/2P2005/054561 - 10 -
2004P16808WOIN
Patent claims
1. A system for setting the speed of a vehicle to a maximum
permissible speed, comprising a limiting device (2) which
limits the attainable traveling speed of the vehicle to a
maximum value by means of engine intervention, and an
information device (1) which prompts the limiting device (2) to
limit the traveling speed to a modified maximum value when the
maximum permissible speed changes during driving, characterized
in that the information device (1) is a device for identifying
the type of road currently being driven on, and in that the
information device (1) reads out the maximum permissible speed
which is associated with the type of road currently being
driven on from a memory device (7) and takes said maximum
permissible speed into account as a modified maximum value.
2. The system as claimed in claim 1, characterized in that
the information device (1) distinguishes between a toll road
and a toll-free road in the case of the type of road currently
being driven on.
3. The system as claimed in either of claims 1 and 2,
characterized in that the information device (1) distinguishes
between classes of road in the case of the type of road
currently being driven on.
4. The system as claimed in one of the preceding claims,
characterized in that the information device (1)

PCT/EP2005/054561 - 11 -
2004P16808WOIN
distinguishes between toll roads with different toll fees in
the case of the type of road currently being driven on.
5. The system as claimed in one of the preceding claims,
characterized in that the information device (1) ascertains a
maximum permissible speed as a function of both the type of
road currently being driven on and also an area currently being
driven through.
6. The system as claimed in claim 5, characterized in that
the area currently being driven through is determined by the
borders of a country.
7. The system as claimed in either of claims 5 and 6,
characterized in that the information device (1) itself
ascertains the area currently being driven through on the basis
of the current position of the vehicle and a road map.
8. The system as claimed in either of claims 5 and 6,
characterized in that the information device (1) is provided
with a wireless reception unit (8) which receives an area
signal, which is transmitted by an external transmission unit
(9), for identifying the area currently being driven through.
9. The system as claimed in one of the preceding claims 1 to
6, characterized in that the information device (1) is provided
with a wireless reception unit (8) which receives the maximum
permissible speeds which are transmitted by an external
transmission unit (9) with a respective type of road,

PCT/EP2005/054561 - 12 -
2004P16808WOIN
and stores said maximum permissible speeds in the memory device
(7).
10. The system as claimed in claims 5 and 7, characterized in
that the external transmission unit (9) carries out the
transmission operation when the vehicle crosses or has just
crossed an area boundary.
11. A method for setting the speed of a vehicle to a maximum
permissible speed, in which method the attainable traveling
speed of the vehicle is limited to a maximum value by means of
engine intervention, and the traveling speed is limited to a
modified maximum value when the maximum permissible speed
changes during driving, characterized in that the type of road
currently being driven on is identified, and in that the
maximum permissible speed which is associated with the type of
road currently being driven on is read out from a memory device
(7) and taken into account as a modified maximum value.

The invention relates to a system and method for setting the speed of a vehicle to a
maximum permissible speed, comprising a limiting device (2) that, by means of
engine intervention, limits the attainable speed of the vehicle to a maximum value,
and comprising an information device (1) that, when the maximum permissible
speed is modified during driving, induces the limiting device (2) to limit the
vehicle speed to a modified maximum value. According to the invention, the
information device (1) is a device for identifying the type of road currently being
driven upon. The information device (1) reads the maximum permissible speed
associated with the type of road currently being driven upon out of a memory
device (7) and considers this maximum permissible speed as a modified maximum
value.

A SYSTEM AND A METHOD FOR SETTING THE SPEED OF A VEHICLE TO A MAXIMUM PERMISSIBLE VALUE

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