FR2962959A1 - DRIVING ASSISTANCE SYSTEM WITH BRAKE CONTROL - Google Patents

Abstract

Vehicle control with a driver assistance system controlling a brake system. The driver assistance system performs the following steps for controlling the brake system via a vehicle interface (106): - determining an indication of the path to be traveled to a set point, - determining an indication of the speed for the path to be traveled, and - providing the thus determined data relating to the path and the speed, by the vehicle interface (106) to the control unit of the brake system.

Description

FIELD OF THE INVENTION The present invention relates to a driving assistance system for controlling the brake system via an interface of the vehicle.

State of the art The driver assistance systems (also called driver assistance systems), include additional facilities on vehicles to assist the driver in certain driving situations. A driver assistance system frequently includes several subsystems, such as, for example, the ABS system (anti-lock system) and / or the ESP system (electronic trajectory stabilization program), a distance control device (ACC system, adaptive cruise control), etc. As a subsystem of a driver assistance system, there may also be a parking assistance system. For an assisted parking maneuver, the parking location is usually measured past the location and then the driver receives directions to be guided into the parking space. The guidance in the parking space can be in passive form, that is to say that the driver receives steering angle warnings as well as start and stop commands. But the parking assistance system can also actively ensure the parking maneuver and in this case, the driver receives only start and stop instructions, the transverse guidance and the longitudinal pipe, being ensured. automatically by the system. In this case, the brake system and the vehicle drive are automatically controlled by the driver assistance system. During the parking maneuver, the distance sensors fitted to the vehicle monitor the environment. The distance of the obstacles can be displayed for the driver and / or the driver can receive information on the risk of collision with objects in the environment. The parking assistance system with a semi-automatic or fully automatic longitudinal drive, allows braking actions to be carried out at

2 stop point of change of direction on a parking route calculated in advance or according to static obstacles or appearing suddenly. For active braking (or acceleration) action, communication between the driver assistance system and the actuators that execute it is required. Thus for the longitudinal pipe, it is necessary to communicate with a brake control unit (for example an ESP module). A corresponding communication exists in current systems in the form of an instantaneous interface. This means that the corresponding system of the driver assistance system provides a desired acceleration value for controlling the braking. A control loop is then implemented between the driver assistance subsystem and the brake control whereby the brake command requests the setpoint acceleration and appropriately controls the actuators. The sensors then capture the resulting movement of the vehicle and the driving assistance subsystem provides the corresponding regulation of the setpoint acceleration. The tolerances achievable with such control loops, are in an order of magnitude of +/- 30 centimeters (cm) with respect to predefined stopping points. DESCRIPTION AND ADVANTAGES OF THE INVENTION The subject of the invention is a method for a driving assistance system for controlling a brake system by a vehicle interface, that is to say a method comprising the following steps: determining an indication of a path to be traveled to a set point, - determining an indication of a speed for the journey, and - providing the indications thus determined for the path and speed via the vehicle interface, to a unit command to control the brake system. In addition or as an alternative to providing a setpoint torque or setpoint acceleration, the driving assistance system requests or provides a previously calculated (residual) path

3 or actively determined a maximum speed or a set speed. If the driving assistance system predefines the desired target quantities in this way, the brake system can in principle automatically regulate the movement of the vehicle based on the target quantities. The transmission of a single piece of information with indication of the path and speed to a brake control is theoretically sufficient to perform the required maneuver completely. The brake system can use the sensor signals available internally in the brake system without further cooperation of the driver assistance system to control the brakes and the engine if necessary and thus regulate the desired movement of the vehicle. The sensor signals to be used for a control circuit internal to the brake system may comprise, for example, the data supplied by the radial pulse counter or the yaw rate sensor as well as the data relating to the longitudinal acceleration and / or or transverse. As the control circuit is implemented internally to the brake system, there is no need in principle to exchange other data between the driver assistance system and the brake control. For example, it relieves a network internal to the vehicle, such as the CAN bus (network controller bus) or other bus systems and thus eliminates the latency inherent in communication operations. The invention thus makes it possible to achieve much more precisely the stopping point or other set point, for example during the parking path, compared with the state of the art, and tolerances in a range of +/- 10 cm. A set point can be a breakpoint, a change of direction point or any other point along the path used for parking. The target speed can for example be the speed to be complied with up to an instantaneous set point on the path in the case of a permanent cyclic recalculation. For example, a set point may be at a distance of 3 m and be approached with an instantaneous set speed of 1 km / h. for the following new calculations, the

The distance and setpoint speed will decrease, for example if it is the set point around a breakpoint or a change of direction. For other setpoints, the set speed does not necessarily return to 0 km / h when approaching these points. The higher stopping accuracy can in turn be the basis for new, powerful parking assistance systems. The more precisely the setpoints are respected along the previously calculated parking path, the better the result of the parking maneuver. For example (respecting the usual safety distances), narrower parking spaces can be considered. The function according to the invention can be applied not only for parking assistance, but also in other subsystems, for example for the ACC (on / off) system for more precise stopping and starting. position. For certain embodiments of the method of the invention, the path to be traveled is determined from the distance data concerning the objects in the vehicle environment and which are in a parking assistance subsystem of the parking system. driving assistance. In addition or alternatively, the path to be traveled may be at least part of a path calculated by the driver assistance subsystem. This advantageously makes it possible to use already existing data, such as, for example, distance data or calculated parking paths. This simplifies the implementation of the driver assistance system according to the invention. The speed of the journey to be traveled may be a set speed on at least a portion of the parking path calculated by the parking assistance subsystem. In principle, the driving assistance system can provide, in segments or continuously, variable setpoint speeds for braking and driving control. This optimizes the operation to be performed, for example the parking maneuver, in speed and comfort, perceived by the driver, etc. For certain embodiments of the method of the invention, there is another step receipt of status information concerning the state of the braking system for the interface, the determination of the indications of path and / or speed and / or the provision of the indications, are made from the status information received. The exchange of status information, for example relating to the vehicle internal communication system, makes it possible to take account of security elements and makes it possible to generally improve the synchronization of the state of the two systems, as well as the availability, robustness or reliability of the relevant driver assistance subsystem (s). According to one development, the brake system is designed to implement different types of brakes and the method comprises another step of providing a predefined indication of one of the different braking modes via the vehicle interface. to the control unit of the brake system. If the interface is used in this way, there are other possibilities of adaptation of the braking or starting operation according to the state of the environment. The invention also relates to a method applied in a control unit of a brake system. The method is characterized by the following steps: - receiving an indication of a path to be traveled to a set point and an indication of the speed relating to the path, transmitted by the interface of the vehicle, * the indications being provided by a driving assistance system for controlling the brake system, and - controlling the brake system according to the received indications concerning the path and the speed. The control of the brake system can be done according to the braking torque and / or the engine torque. The method also includes the further step of providing status information of the brake system status via the interface for the driver assistance system. The invention also relates to a computer program product for implementing the method such as

6 described above, when the computer program is executed by a computer. The computer or computer may for example be a module implementing a subsystem of a driving assistance system and / or a brake control in a vehicle. The computer program product can be recorded on a machine-readable memory medium, such as a permanent or rewritable memory medium, or be associated with a computer installation or be recorded on a CD-ROM, a DVD or a USB key. In addition or alternatively, the computer program product can be provided by a computer installation by downloading, for example via a data transmission network, such as the internet or a communication link. such as a telephone line or a wireless link. The invention also relates to a driver assistance system (or driver assistance system), designed to control a brake system via a vehicle interface. The driving assistance system is characterized by comprising: - an installation for determining an indication of the path to be traveled to a set point, - an installation for determining an indication of the speed relating to the path, and - an installation for providing the specified route and speed indications, through the vehicle interface for a brake system control unit. Such a driver assistance system has the advantage of minimizing the memory location (ROM, RAM) required to develop the longitudinal driving function in the driver assistance system. The means to implement for the application at the level of the driving assistance system, are reduced because the regulation itself is only on the side of the brake control and the functions of the other brake functions that already exist, can be taken back what is translated globally

7 by implementing implementation means of the invention, reduced to a minimum. The invention also relates to a control unit characterized in that it comprises: - an installation for receiving an indication of the path to be traveled to a set point, and an indication of a speed for the journey to be traveled by means of a vehicle interface, * indications being provided by a driving assistance system for controlling the brake system, and - an installation for controlling the brake system on the basis of the indications received concerning the ride and speed. Finally, the subject of the invention is a vehicle control, characterized in that it comprises: a communications network connecting a plurality of separate vehicle control systems and having at least one vehicle interface; a vehicle assistance system; driving and a control unit of a brake system as defined above. The technique according to the invention can be applied for example to driving assistance systems using ultrasonic detectors, radar detectors or video detectors. Drawings The method of controlling a brake system in a driving assistance system according to the invention, as well as a control unit of a brake system and a vehicle control according to the invention, will be described in As an example in the accompanying drawings in which: - Figure 1 shows schematically an embodiment of a vehicle control according to the invention, - Figure 2 shows a block diagram of the main components of the system of assistance of FIG. 3 shows a block diagram of the main components of a control unit of the brake system of FIG. 1, FIG. FIG. 1

FIG. 5 shows an operating flow diagram of the control unit of FIG. 4. DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIG. 1 schematically shows an exemplary embodiment of a vehicle control 100 according to the invention . A driver assistance system 102 and a control unit 104 of a braking system that is not otherwise shown, are both connected to a CAN bus 106 (instead of the CAN bus, it could also be used as a communication system 106, any other bus system, such as for example the FlexRay system). The driver assistance system 102 includes a parking assistance subsystem (parking assist subsystem) formed of the components 108 and 110; the component 108 is for example a parking assistance system (PAS system) and the component 110, for example is a parking guidance control (PSC control). The components 108 and 110 communicate with each other and with a parking stop component (PS component) 112, made according to the invention for transmitting the data 114 via the bus 106 to the brake control 104, as will be detailed hereinafter. after. The brake control unit 104 comprises a longitudinal control installation 116 and a brake coordinator 118. The control installation 116 converts the control data received from the driver assistance system 102 via the bus 106, into data of the driver. control 120 used internally in the control 104 of the brake system. The coordinator 118 finally controls the vehicle brake system by means of the control signals 122. The control signals 122 may include an indication of the braking torque and / or the engine torque. The driving assistance system 102 (for example an ECU unit, an electronic control unit), controls via an interface 106 and with the indication 114 of path and speed (no indication of torque ) the control system 104 (for example an ESP system, "electronic trajectory stabilization program"),

9 this system ensuring the control of the brake system by the couples 122. Figure 2 shows an embodiment of the invention according to the parking stop component 112 of Figure 1, in a more detailed representation. The parking stop component 112 has a reception unit 202, a calculation unit 204, a control data transmission unit 206 and a data exploitation unit. state 208. An operating mode of the PS component 112 will be described hereinafter using the flowchart of FIG. 3. In principle, the PS component 112 for the control of the brake system 104, uses the interface 106 of the vehicle (step 300). The example described here in a practical manner relates to the conversion according to the invention for a parking stop function of the parking assistance system 108, 110. In step 302, components 202 and 204 are transmitted to indication of the journey to the stopping point. For this reason, distance data with respect to obstacles, where to stop and / or stopping points and / or change of direction or other set points (along) a parking lot calculated, and which are in the units 108 and 110 of the parking assistance subsystem, are taken into account by the reception unit 202. The reception unit 202 can passively receive the data of the units 108 and 110 or ask them actively. The reception unit 202 transmits the received data to the computing unit 204; the latter processes the data appropriately in an indication of the path to be traveled (residual path) to the next set point. The path to be traveled may be a segment of a parking path calculated by the parking assistance subsystem 108, 110. The path may be calculated for example from a calculated set point and at any time, the calculation is corrected or updated by the distance data measured against the characteristic obstacles. In step 304, the components 202 and 204 determine a speed indication for the calculated path in step 302.

This speed may be the maximum speed or a set speed along the path to be traveled. It can also be calculated by receiving data from the units of the parking assistance subsystem 108, 110 and / or calculating from predefined data. Such data may be contained in a data memory 210 associated with the PS component 112. Various examples for determining the set speed will be discussed below. According to a first example, the guidance function for the parking assistance system must only be active for example up to a maximum speed of 10 km / h (km / h), for example because of a regulation (In another example, the limit could be set for example at a maximum speed of 5 km / h). For speeds above this limit, the guidance function will be stopped, which generally results in the stopping of the parking operation. Therefore, the maximum speed or set speed must be set in this case so that the guidance function is not stopped. By way of example, the set speed can be preset fixedly to a value of 9.5 km / h and be recorded as such in the memory 210. According to a second exemplary embodiment, the speed of maximum guidance possible to provide guidance with a required steering angle. If the vehicle is traveling too fast, the required steering angle can not be established quickly enough.

This would result in deviations from the calculated parking lot and, if necessary, result in the stopping of the parking maneuver. Taking this consideration into account, the set speed must be set so that the steering can respond to the calculated movement of the vehicle. For this, a fixed setpoint speed, for example 5 km / h, can be stored in the memory 210, to be available for the calculation unit 204. In the place of preset target speeds, depending on the position current vehicle (depending on events or a cyclical finding), we can determine a maximum possible speed relative to the position. The reception unit 202 can receive

11 event-related data or cyclical data of the parking assistance subsystem 108, 110, other subsystems of the driver assistance system 102 or also directly of a sensor system.

In another example, it is taken into account that the driver must have a comfortable impression during the parking maneuver. For this, depending on the residual path to be traveled and depending on the driving maneuver, for example a curve path, a straight line path and a distance from potential obstacles, the driver assistance system 102 defines also dynamically, the set speed and provides it to the control 104 of the brake system via the bus 106. According to a more complex example, a parking path is run after a stop behind a suitable parking space and until the first turn in the parking space, as quickly as possible, that is to say substantially at a maximum speed of 9.5 km / h. By pointing into the parking space itself, the maximum possible steering speed must be respected, ie the maximum speed is then only about 5 km / h. The residual path to the last stopping point in the parking space could be traveled in principle at the same constant speed. But by experience, this would be perceived by the driver as corresponding to an acceleration and thus creates an effect of discomfort. On the last part of the parking path, the driver assistance system can force in a suitable frame, a gradual reduction perceived as comfortable, of the set speed by instructions appropriate to the control of brakes. Step 304 of FIG. 3 follows step 302. In other exemplary embodiments, step 304 is executed in parallel with step 302, or even before step 302. step 306, the unit 208 receives, via the bus system 106, status information regarding the state of the brake system. This information is provided by the control unit 104. In general, the assistance system of

12 driving 102 and the brake control 104, could also use state information such as the states "inactive", "restart", "ready", "not activatable", "activated", "finished", "error" , etc., to compensate for the state configuration ("machine state") of the driver assistance system 102 or the brake system 104. Such an exchange of status information is, among other things, advantageous from the point of view of The status information received from the unit 208 may be transmitted in a form appropriate to the computing unit 204 which may take into account the brake control status information to determine the indications relating to the Alternatively or additionally, the unit 204 or 206 can also determine this status information to use the indications transmitted by the bus 106. By way of example, from the information of FIG. state, it will be possible to determine the moment at which the indications of In step 308, the supply unit 206 takes the indications transmitted by the calculation unit 204 relating to the path and the speed, and makes them available to the brake control 104 via the control unit. This control data 114 can be actively sent to the brake control 104 or the brake controller 104 can request the data 114 from the driver assistance system 102. The step 308 can also be sent to the brake control 104. comprise providing status information to the control unit 104. Because of the simple state information concerning the driver assistance system 102, additional control information can also be transmitted in this manner. If, for example, the brake system is designed to perform different braking modes, step 308 may include providing a predefined indication of one of these different braking modes. The indication may for example relate to one of the different braking modes of the brake system, such as "comfort mode" and "emergency mode".

The method 310 ends with the receipt of the indications relating to the path and the speed, by the brake control 104. FIG. 4 schematically shows the main components according to the invention of an example embodiment of the control system. 116. The control system 116 comprises a control data reception unit 402, a state data transmission / reception unit 404 and a calculation unit 406. An example of operation of the control unit 116 will be given below with reference to the flowchart of FIG. 5. In principle, the control system 116 controls the brake system based on the data received from the driver assistance system 102, via the bus 106 (step 500). In step 502, the computing unit 406 calculates a state of the brake system as well as the status information representing this state from the sensor data received from a vehicle sensor system, not shown in FIG. the figures. This information is provided to the other vehicle systems, such as the driver assistance system 102, by an input / output unit 404 and the bus system 106. In the unit 504, the receiving unit 402 receives the data 114 (see FIG. 1) through the vehicle interface represented by the bus 106 from the driver assistance system 102. The data includes an indication of a path to be traveled to a set point and an indication. speed on the journey. In step 506, the receiving unit receives the state information of the driver assistance system 102 with additional data relating for example to the execution of a certain braking mode.

In step 508, the calculation unit 406 calculates one or more internal setpoint values 120 from the received target values 114 and, if appropriate, information received by the unit 404 (see FIG. 1). In step 510, these internal control variables 120, are provided by the longitudinal control facility 116, to other installations of the brake control.

14 104, such as, for example, the coordinator 118 shown in FIG. 1. Starting from the internal setpoints 120 which can for example represent an acceleration, the coordinator 118 calculates, for example, the forces to be supplied or the braking and / or motor and provides this information (arrow 122, Figure 1). Internal regulation of the brake system to respect the internal set point value 120 is then carried out in a manner known per se. The process sketched in FIG. 5 ends with the entry into the internal regulation loop (step 512).

For the internal control of the brake, it should be noted that the input data 114 comprise in particular the path and the target speed, whereas the transmission 120 of the control unit 116 comprises, for example, an acceleration of setpoint. This acceleration can be adapted quickly to the speed path setpoint value 114 by the control unit 116, since this control loop implemented solely in the brake control 104 will react faster than a necessary tuning. in the current systems, between the driver assistance system and the brake control, via the internal bus system of the vehicle. The methods described above can be performed for example several times, successively, for a parking path. The residual path transmitted by the bus can relate for example to the same setpoint, with each time modified target speeds. The invention is not limited to the embodiments described and the aspects highlighted. Moreover, a large number of variants are possible within the scope of the invention.

15 NOMENCLATURE

100 vehicle control 102 driver assistance system 104 brake control 106 CAN bus 108, 110 parking assistance subsystem component 112 parking stop component PS 114 route and speed indications 116 installation of longitudinal control 118 brake coordinator 120 control data 122 torque 202 receiving unit 204 calculation unit 206 control data output unit 208 status data operating unit 210 data memory 300-310 operating process steps of the PS 112 component 402 control data reception unit 404 state data transmission / reception unit 406 calculation unit 500-512 operating steps of the control unit 11625

Claims (1)

CLAIMS 1 °) A method applied by a driving assistance system for controlling a brake system by a vehicle interface, characterized by the following steps: - determining an indication of a path to travel to a set point, - determining an indication of a speed for the path, and - providing the indications thus determined for the path and speed via the vehicle interface, to a control unit for controlling the brake system. Method according to claim 1, characterized in that the path to be traveled is determined on the basis of distance data of the objects in the vehicle environment, which are available in the assistance subsystem. the parking assistance system and / or the journey to be traveled which is at least one segment of a parking distance calculated by the parking assistance subsystem. Method according to claim 1, characterized in that the speed of the journey to be traveled is a set speed of at least one segment of the parking path calculated by the parking assistance subsystem. Method according to Claim 1, characterized by another step of receiving status information concerning a state of the brake system, via the interface of the vehicle, determining the route indications and / or the method of claim 1, characterized in that the brake system is designed to execute different braking modes, and - Furthermore by the step of providing a predefined indication of one of the different braking modes by the vehicle interface to the control unit providing control of the brake system. 6) A method applied in a control unit of a brake system, characterized by the following steps: - receiving an indication of a path to be traveled to a set point and an indication of the speed relating to the route, transmitted by the vehicle interface, * the information being provided by a driving assistance system for controlling the brake system, and - controlling the brake system according to the information received on the path and the speed. The method of claim 6, characterized by the step of: providing status information regarding a state of the brake system through the interface to the driver assistance system. 8 °) computer program for implementing the method according to any one of claims 1 to 7, when the computer program is executed by a programmable computer installation. 9 °) Driver assistance system designed to control a brake system via a vehicle interface, characterized by the following components: - an installation for determining an indication of the journey to be made to a vehicle set point, 18 - an installation for determining an indication of the speed relating to the journey, and - an installation for providing the specified indications of the path and speed, via the vehicle interface for a brake system control unit . 10 °) Control unit of a brake system, characterized by the following components: - an installation for receiving an indication of the path to be traveled to a set point, and an indication of a speed for the journey to be traveled by means of a vehicle interface, * indications being provided by a driving assistance system for controlling the brake system, and - an installation for controlling the brake system on the basis of the indications received concerning the ride and speed. Vehicle control comprising: - a communications network connecting a plurality of separate vehicle control systems and having at least one vehicle interface; - a driving assistance system according to claim 9; and - a control unit for controlling a vehicle. a brake system according to claim 10.