METHOD AND DEVICE FOR CONTROLLING THE PEDALS OF A VEHICLE

Description

[0001] The present invention relates to a method for operating a driver model for controlling a vehicle, a control device, the use of the control device for carrying out a test run for a vehicle and a computer program product.

[0002] In the state of the art, driver models are known, such as algorithms for controlling a vehicle, which use a PI controller to determine a pedal value for adjusting, for example, an accelerator pedal of a vehicle solely as a function of a difference between a current vehicle speed and a predetermined vehicle speed.

[0003] For example, patent US5430645A discloses an on-board robotic system for controlling acceleration, cruising, coasting, braking, and idling of electric vehicles. The system includes a microprocessor with non-volatile memory, a stall detection module, an anti-roll module, a brake trigger, and a switch, as well as several customized sensors and transducers for operating various controls of the electric vehicle.

[0004] The patent DE 4240756 A1 discloses a robot for operating a motor vehicle that is capable of safely stopping the motor vehicle's engine even in the event of an unforeseen malfunction, such as a power failure or an operating error.

[0005] Patent DE4103579 A1 discloses an automatic test vehicle drive system in conjunction with a chassis dynamometer, wherein a table indicating a relationship between the stroke of the accelerator actuator and the engine output torque, as well as a table indicating a relationship between the engine friction power loss and the engine speed, are stored by a teaching process prior to the driving test of the vehicle.

[0006] A driver model operated as described above often leads to erratic adjustments of a vehicle with strong acceleration and a correspondingly unnecessarily high fuel consumption or pollutant emissions.

[0007] The object of the present invention is to at least partially address the problems described above. In particular, the object of the present invention is to provide a driver model that operates a vehicle in a fuel-efficient and low-emission manner.

[0008] The above object is achieved by the patent claims. In particular, the above object is achieved by the subject matter of the respective independent patent claims. Further advantages of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the presented method naturally also apply in connection with the control device according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0009] According to a first aspect of the present invention, a method for operating a driver model for controlling a vehicle for conducting a test run for this vehicle on a test bench is presented. The driver model comprises a vehicle module that determines a pedal position to be set on the vehicle. Furthermore, the vehicle module determines a required power as a proportion of a total power that can be delivered by a drive of the vehicle, wherein the required power corresponds to a power required to move the vehicle at a required speed and / or a required acceleration along a predetermined road course.Furthermore, the presented method provides that a value of a permissible pedal position is assigned to the required power, and the value of the permissible pedal position, in particular an accelerator pedal position, is transferred to the driver model for controlling the vehicle. It is provided that the driver model comprises a control module by means of which a control value for adjusting the accelerator pedal is determined, wherein the control value is dynamically limited by an upper limit value determined based on the value of the permissible pedal position.

[0010] In the context of the present disclosure, a driver model is understood to mean an algorithm used to control a vehicle. In particular, a driver model can be used to control driving functions, such as adjusting the respective pedals of a vehicle.

[0011] The presented method serves in particular to limit the power to be provided by a vehicle in order to avoid unnecessary acceleration jumps, such as those typical when a vehicle is operated by a driver model, for example during a gear change. For this purpose, the presented method provides for the determination of a required power that is determined for a predetermined road course. The predetermined road course can in particular be a road course detected by at least one sensor of the vehicle and / or a road course determined by means of a digital map for a respective route to be traveled. For example, a predetermined road course can be a section of a road for which a vehicle speed to be set is specified according to a predetermined test protocol.

[0012] The required power provided according to the invention is determined or specified as a proportion of the total power potentially deliverable by a vehicle, e.g. in "%".

[0013] The required power provided by the invention is requested from a drive system of a respective vehicle in order to achieve a predetermined acceleration and a predetermined vehicle speed for a given route. To this end, the driver model provided by the invention adjusts the vehicle such that the vehicle provides the required power. For this purpose, a computing unit, using an assignment table or an assignment function, assigns a value of a permissible pedal position to a respectively determined required power, and the value of the permissible pedal position is transferred to the driver model provided by the invention.

[0014] As soon as the driver model receives the value of the permissible pedal position from the vehicle module or determines the value of the permissible pedal position using the vehicle module, the driver model can adjust the respective pedals of the vehicle to be controlled according to the value of the permissible pedal position. For this purpose, for example, the value of the permissible pedal position can be transferred to a pedal control unit so that the pedal control unit moves a respective pedal, in particular an accelerator pedal of the vehicle, at most to a position that corresponds to or essentially corresponds to the value of the permissible pedal position. The position of the pedal essentially corresponds to the value of the permissible pedal position when the pedal is in a position that corresponds to the value of the permissible pedal position plus or minus a predetermined tolerance amount of, for example, 5%, preferably 2%, particularly preferably 0.5%.

[0015] The value of the permissible pedal position provided according to the invention serves in particular as a limit value beyond which or below which a pedal position to be set by a driver model should or may not be changed.

[0016] Accordingly, the value of the permissible pedal position provided according to the invention acts as a control instance which is superimposed on a respective control system used by a driver model to control a vehicle, such as a PI controller, so that in the event that the driver model specifies a control value which leads to a pedal position which is above or below the value of the permissible pedal position, the control value is automatically replaced by the value of the permissible pedal position or the control value is automatically adjusted in accordance with the value of the permissible pedal position.

[0017] In other words, the presented method limits or throttles the performance of a vehicle depending on the vehicle speed and acceleration required to achieve a certain road course or section of road.

[0018] Using the presented method, a PID controller for controlling a pedal control unit can be dispensed with in one embodiment, and instead a corresponding vehicle or a corresponding pedal control unit can be controlled directly using the values ​​for a permissible pedal position determined according to the invention. Alternatively, it can be provided that a PID controller is used to smooth a plurality of values ​​for a permissible pedal position determined according to the invention.

[0019] In order to use the value of the permissible pedal position provided according to the invention for controlling a vehicle, the value of the permissible pedal position can be transferred to a control module which converts the value of the permissible pedal position into a limit value which is used as the basis for a control process for adjusting a pedal.

[0020] The control module can, for example, be a PI controller or a PID controller designed to determine a control value of a pedal of a vehicle.

[0021] It can be provided that the required power provided according to the invention is provided by adjusting a brake pedal of the vehicle according to a value for a permissible brake pedal position.

[0022] It can further be provided that the upper limit value for the control value of a respective pedal is determined by means of the control module in that, in the event that a power requirement to be provided by the drive of the vehicle increases, the upper limit value of the power requirement is increased accordingly, and in the event that the current power requirement is smaller than a weighted characteristic value which corresponds to a value weighted with a weighting factor of a power requirement immediately preceding the current power requirement, the weighted value is selected as the upper limit value.

[0023] By means of an upper limit value, which is adjusted depending on a current power requirement to be provided by a drive of a vehicle, a dynamic, i.e. continuously adjusted, limitation of a power output of the vehicle can be achieved, so that even during an acceleration process an operating state in which the vehicle is operated in a fuel-inefficient manner or with increased or suboptimal pollutant emissions is avoided.

[0024] It may also be provided that the weighting factor corresponds to a value less than one.

[0025] In particular, the weighting factor can correspond to a value of "0.999".

[0026] It can be provided that a transfer value that is passed to a control module for determining the upper limit value corresponds to a value of the permissible pedal position that has been multiplied by a factor, such as the factor "1.5".

[0027] By using a factored value of the permissible pedal position as a transfer value for determining an upper limit value by a control module, the upper limit value can be formed with a tolerance surcharge, so that the vehicle can also be operated in an operating state which, within a tolerance band specified by a corresponding factor, releases more power than is provided for by the value of the permissible pedal position itself.

[0028] It can further be provided that the control value is limited by a lower limit value, whereby the lower limit value is determined on the basis of the value of the permissible pedal position or the lower limit value is fixed.

[0029] A lower limit can be used to specify the minimum power at which a vehicle will operate for a given power requirement. The lower limit can be determined based on the permissible pedal position, resulting in an upper and lower limit that changes depending on the permissible pedal position.

[0030] It can further be provided that the driver model comprises a target acceleration determination module, by means of which an acceleration performance to be provided by the vehicle is determined by determining a speed difference between a speed required for at least one future point in time and a speed required for a current point in time. Based on the determined speed difference, an acceleration performance required to compensate for the speed difference is determined. It is further provided that the target acceleration determination module transfers the determined acceleration performance to the driver model as the required acceleration performance.

[0031] A speed difference between a required speed for at least one future point in time and a required speed for a current point in time can be used to create a prediction period for which a required acceleration power can be calculated based on the speed difference. With a prediction period of a known or predetermined duration, a speed difference expected at a known point in time—namely, the end of the prediction period—assuming constant vehicle behavior can be transformed into an acceleration power required to overcome the speed difference within the prediction period. A prediction period can, for example, last between 0.001 seconds and 5 seconds, in particular between 0.001 seconds and 2 seconds.

[0032] It can further be provided that a required acceleration power is determined based on a plurality of speed differences for a plurality of future required speeds. For example, it can be provided that a speed difference and a corresponding acceleration power are determined for each second within a prediction period. It can be provided that a future required speed is determined with a predetermined operating cycle of, for example, 100 milliseconds or 1000 milliseconds. Accordingly, a corresponding acceleration power can be determined for each operating cycle.

[0033] Based on the determined acceleration power, a required power can be determined that must be set on a vehicle to accelerate the vehicle with the determined acceleration power, so that the vehicle reaches the specified speed within the prediction period or minimizes the speed difference. For this purpose, a required power or a corresponding value of a permissible pedal position can be assigned to a respective acceleration power, for example, using an assignment table or an assignment function.

[0034] InIn a second aspect, the presented invention relates to a control device for operating a driver model for controlling a vehicle. To carry out a test run for this vehicle, the control device comprises a driver module configured to operate the driver model. The driver module comprises a vehicle module configured to determine a pedal position to be set on the vehicle. The driver module comprises a demand determination module configured to determine a required power as a proportion of a total power that can be provided by a drive of the vehicle, wherein the required power corresponds to a power that is required to move the vehicle at a required speed and / or a required acceleration along a predetermined route.Furthermore, the driver module comprises an assignment module configured to assign a value of a permissible pedal position to the required power, and a transfer module configured to transfer the value of the permissible pedal position to the driver model for controlling the vehicle. It is provided that the driver module comprises a control module configured to determine a control value for adjusting an accelerator pedal, wherein the control module is configured to dynamically limit the control value by an upper limit and to determine the upper limit based on the value of the permissible pedal position.

[0035] Thus, a method according to the invention brings with it the same advantages as have been described in detail with reference to the device according to the invention.

[0036] It can further be provided that the driver module comprises a target acceleration determination module which is configured to determine an acceleration power to be provided by the vehicle by determining a speed difference between a speed required for at least one future point in time and a speed required for a current point in time and, based on the determined speed difference, determining the acceleration power to be provided to compensate for the speed difference, wherein the driver module is configured to transfer the determined acceleration power to be provided to the driver model as the required acceleration power.

[0037] The target acceleration determination module can determine a required target acceleration performance, for example, using formula (1).

[0038] The following applies corresponds to a required target acceleration performance, a required target speed, "v act " a current speed and "t" the time in [seconds].

[0039] In a third aspect, the presented invention relates to the use of the presented control device for carrying out a test run for a vehicle.

[0040] To carry out a test run, such as a test run for recording vehicle emissions in real operation, the control device presented can control a vehicle to be tested using respectively determined pedal positions or respectively determined speed and / or acceleration values.

[0041] In a fourth aspect, the presented invention relates to a computer program product comprising program code means that configure a computer to perform all steps according to at least one possible embodiment of the presented method when these are executed on the computer.

[0042] The computer program product according to the invention can be implemented as computer-readable instruction code in any suitable programming language, such as JAVA or C++. The computer program product can be stored on a computer-readable storage medium, such as a data disk, a removable drive, a volatile or non-volatile memory, or a built-in memory / processor. The instruction code can program a computer or other programmable devices, such as the control device, in such a way that the desired functions are carried out. Furthermore, the computer program product can be provided in a network, such as the Internet, from which it can be downloaded by a user as needed. The computer program product can be implemented both by means of a computer program, i.e. software, and by means of one or more special electronic circuits, i.e. in hardware, or in any desired hybrid form, i.e.i.e. by means of software components and hardware components.

[0043] Further measures improving the invention will become apparent from the following description of various exemplary embodiments of the invention, which are schematically illustrated in the figures. All features and / or advantages apparent from the claims, the description, or the figures, including structural details and spatial arrangements, may be essential to the invention both individually and in various combinations.

[0044] They show schematically: Figure 1 shows a flowchart of a possible embodiment of the method according to the invention. Figure 2 shows a representation of a possible embodiment of the control device according to the invention. Figure 3 shows a visualization of a possible embodiment of a control module.

[0045] In Fig. 1A process 100 of a possible embodiment of the presented method is shown schematically.

[0046] In a first determination step 101, a pedal position to be set on a vehicle, in this case an accelerator pedal position, is determined by means of a driver module of a driver model that is executed on a computer.

[0047] To determine the accelerator pedal position to be set on the vehicle, the driver module determines, in a second determination step 103, a required power as a proportion of a total power that can be provided by a vehicle's drive. The required power corresponds to the power required to move the vehicle at a required speed, i.e., a speed specified for a given road course, and a required acceleration along the given road course. The required acceleration power can be determined, for example, based on the required speed, for example, by determining a speed difference between a current vehicle speed and a speed required at a known time.The required acceleration corresponds to the acceleration that is needed to reach the required speed at the known time, starting from the current speed at the known time.

[0048] In an assignment step 105, a value of a permissible accelerator pedal position is assigned to the determined required power. The value of the permissible accelerator pedal position is selected such that, while providing the determined required power, fuel consumption and / or pollutant emissions of the vehicle are minimized.

[0049] In a transfer step 107, the value of the permissible accelerator pedal position is transferred to the driver model for controlling the vehicle. Accordingly, the driver model, for example, controls a pedal control device such that a vehicle pedal is moved no more than the value of the permissible accelerator pedal position. For this purpose, the driver model can, for example, send a corresponding control command that configures the pedal control device to move the pedal according to a characteristic curve specified by the control command or that specifies a corresponding limit value for the pedal control device that limits pedal movement according to the value of the permissible accelerator pedal position.

[0050] The driver module uses a vehicle model to determine a relative demand power using formulas (2) and (3).

[0051] Where: "v dem " is a current target speed in meters per second and where and "P rel" corresponds to a demand performance, P the a required performance, Pmax a maximum performance of a respective vehicle, v the a required speed. The parameters m , Pmax, A 0 , B 0 and C 0 are variables of the function, the acceleration due to gravity g corresponds to 9.81 m / s 2< squared and the angle of inclination is determined by

[0052] In Fig. 2 A control device 200 is shown. The control device 200 includes a driver module 201 configured to operate a driver model.

[0053] The driver module 201 includes a vehicle module 203 configured to determine an accelerator pedal position to be set on the vehicle.

[0054] Furthermore, the driver module 201 comprises a demand determination module 205, which is configured to determine a demand power as a proportion of a total power that can be provided by a drive of the vehicle, wherein the demand power corresponds to a power that is required to move the vehicle at a required speed and / or a required acceleration along a predetermined route.

[0055] Furthermore, the driver module 201 comprises an assignment module 207 which is configured to assign a value of a permissible accelerator pedal position to the required power.

[0056] Furthermore, the driver module 201 comprises a transfer module 209 which is configured to transfer the value of the permissible pedal position to the driver model for controlling the vehicle.

[0057] By means of an interface 211, which can be designed, for example, as a wireless interface or as a wired interface, the control device 200 is in communicative connection with a vehicle or an actuator, such as a pedal actuator, for controlling a vehicle.

[0058] In Fig. 3 A control module 300 is shown. The control module 300 comprises a determination unit 301 for adaptively or dynamically determining an upper limit and a lower limit of a permissible accelerator pedal position.

[0059] As input signals, the determination unit 301 receives a current value of an accelerator pedal position 303 from a pedal pre-control unit and a predefined minimum value function 305, based on which the lower limit is directly determined. The predefined minimum value function 305 can, for example, be a function or an assignment table for determining a minimum position of an accelerator pedal.

[0060] Furthermore, the determination unit 301 determines the upper limit of the permissible accelerator pedal position based on a required power required for a respective road course or route section.

[0061] Furthermore, the control module 300 comprises a PID controller 307, which determines a value 313 for adjusting the accelerator pedal of the vehicle based on a current vehicle acceleration 309 and an acceleration 311 required for the respective road course or section of road.

[0062] The determination unit 301 compares a value 313 determined by the PID controller for adjusting the accelerator pedal with the lower and upper limit values. If the value determined by the PID controller 307 is greater than the upper limit or less than the lower limit, a corresponding movement of the accelerator pedal above the upper limit or below the lower limit is prevented, for example, by replacing the value determined by the PID controller 307 with the upper or lower limit.

[0063] Alternatively, it can be provided that the PID controller 307 is replaced by the determination module or that the PID controller 307 is connected downstream of the determination module in order to smooth values ​​determined by the determination module or to compensate for fluctuations in the values ​​determined by the determination module.

[0064] The upper limit and the lower limit are continuously updated depending on the road layout and a current vehicle speed and / or the current speed of the vehicle.

[0065] The value for adjusting the accelerator pedal can be determined, for example, using the following formulas (4), (5):

[0066] Formula (4) applies to the following condition: u ( t ) ≥ 0.999 y ( t - 1), otherwise formula (5) applies.

[0067] The following applies: " y ( t )" corresponds to a value for setting an accelerator pedal, " u ( t )" an input value, such as a value factored by a factor of in particular 1.5 for adjusting an accelerator pedal, which was determined in a current point in time immediately preceding the adjustment step, "t" corresponds to the time in [seconds], "0.999" a weighting value.

[0068] The invention allows for further design principles in addition to the embodiments illustrated. This means that the invention should not be considered limited to the embodiments explained with reference to the figures. List of reference symbols

[0069] 100Process 101First determination step 103Second determination step 105Assignment step 107Transfer step 200Control device 201Driver module 203Vehicle module 205Demand determination module 207Assignment module 209Transfer module 211Interface 300Control module 301Determination unit 303Value of an accelerator pedal position 305Minimal value function 307PID controller 309Value of a current vehicle acceleration 311Required acceleration 313Value for setting the accelerator pedal

Claims

1. Method of operating a driver model for controlling a vehicle to perform a test run for said vehicle, wherein the driver model comprises a vehicle module (203) which determines a pedal position to be set on the vehicle, wherein a required power is determined by means of the vehicle module (203) as a component of a total power which can be provided by a drive system of the vehicle, wherein the required power corresponds to a power required to move the vehicle at a required speed and / or a required acceleration (311) along a predefined road course, and wherein a value (313) of a permissible pedal position is assigned to the required power, and wherein the value (313) of the permissible pedal position is transmitted to the driver model for controlling the vehicle, characterized in that the driver model comprises a control module (300) by means of which a actuating value for adjusting the accelerator pedal is determined, the control value being dynamically limited by an upper limit value which is determined on the basis of the value (313) of the permissible pedal position.

2. Method according to claim 1, characterized in that the control module (300) is used to determine the upper limit value for the actuating value of the pedal by increasing the upper limit value of the power demand accordingly in the event that a power demand to be provided by the drive system of the vehicle increases, and in the event that the current power requirement is less than a weighted characteristic value that corresponds to a value weighted with a weighting factor of a power requirement immediately preceding the current power requirement, the weighted value is selected as the upper limit value.

3. Method according to claim 2, characterized in that a transmitted value which is transmitted to the control module (300) to determine the upper limit value corresponds to a value of the permissible pedal position which was multiplied by a factor.

4. Method according to claim 2 or 3, characterized in that the weighting factor corresponds to a value less than one.

5. Method according to one of claims 1 to 4, characterized in that the control module (300) adjusts the actuating value by means of a PID controller (307).

6. Method according to one of claims 1 to 5, characterized in that the actuating value is limited by a lower limit value, wherein the lower limit value is determined on the basis of the value (313) of the permissible pedal position or the lower limit value is specified.

7. Method according to one of the preceding claims, characterized in that the driver model comprises a target acceleration determination module by means of which an acceleration power to be provided by the vehicle is determined in that a speed difference between a speed required for at least one future time and a speed required for a current time is determined, and an acceleration power required in order to equalise the difference in speed is determined on the basis of the determined difference in speed, and the target acceleration determination module transmits the determined required acceleration power to the driver model as the required acceleration power.

8. Method according to one of the preceding claims, characterized in that the predefined course of the road is a road course registered by means of at least one sensor of the vehicle and / or a road course determined by means of a digital map for a respective route which is to be driven.

9. Control device (200) for operating a driver model for controlling a vehicle, the control device comprising a driver module (201) configured to operate the driver model to perform a test run for that vehicle, wherein the driver module comprising a vehicle module (203) configured to determine a pedal position to be set on the vehicle, whereby the driver module comprises a requirement determination module (205) configured to determine a required power as a component of a total power that can be generated by a drive system of the vehicle, wherein the required power corresponds to a power that is necessary for moving the vehicle at a required speed and / or a required acceleration along a predefined road course, and wherein the driver module comprises an assignment module (207) which is configured to assign a value (313) of a permissible pedal position to the required power, and wherein the driver module comprises a transmitter module (209) configured to transmit the value (313) of the permitted pedal position to the driver model for controlling the vehicle, characterized in that the driver module comprises a control module (300) configured to determine an actuating value for adjusting the accelerator pedal, wherein the control module (300) is configured to dynamically limit the actuating value by an upper limit value, and to determine the upper limit value on the basis of the value (313) of the permissible pedal position.

10. Control device according to claim 9, characterized in that the driver module (201) comprises a target acceleration determination module configured to an acceleration power to be provided by the vehicle in that a difference in speed between a speed required for at least a future time and a speed required for a current time is determined, and using the determined difference in speed to determine the acceleration power required in order to equalise the difference in speed, wherein the driver module (201) is configured to determine the required acceleration power to the driver model as the required acceleration power.

11. Use of a control device (200) according to any one of claims 9 or 10, to carry out a test run for a vehicle.

12. Computer program product comprising program code means which configure a computer to carry out all of the steps according of at least one method of claims 1 to 8 when executed on the computer.