METHOD FOR DRIVE CONTROL

Abstract

A method for the drive control of actuators of at least one wheel of a vehicle. The method includes: sensing a desired acceleration; sensing a vehicle velocity of the vehicle; sensing a wheel velocity of the wheel determining a status description of the wheel from the wheel velocity and a wheel acceleration; determining a first value of a target wheel acceleration from the status description, a slip of the wheel, and the desired acceleration; determining a second value of the target wheel acceleration from the wheel velocity, the wheel acceleration and the slip, wherein the second value is a function of correction factors of at least one matrix; and determining a third value of the target wheel acceleration, which value controls the actuators of the at least one wheel, wherein the third value is a function of the first value and of the second value.

Claims

1-11 (canceled)

12. A method for a drive control of actuators of at least one wheel of a vehicle, comprising the following steps: sensing a desired acceleration; sensing a vehicle velocity of the vehicle; sensing a wheel velocity of the wheel; determining a status description of the wheel from the wheel velocity and a wheel acceleration, wherein the status description includes a static description which is a function of the wheel velocity and of the wheel acceleration; determining a first value of a target wheel acceleration from the status description, a slip of the wheel, and the desired acceleration, wherein the slip is a function of the wheel velocity and the vehicle velocity; determining a second value of the target wheel acceleration from the wheel velocity, the wheel acceleration, and the slip, wherein the second value is a function of correction factors of at least one matrix; and determining a third value of the target wheel acceleration, the third value controlling the actuators of the at least one wheel, wherein the third value is a function of the first value and of the second value.

13. The method according to claim 12, wherein the status description of the wheel further includes a dynamic description which is a function of the wheel acceleration and a wheel dynamic.

14. The method according to claim 13, wherein the status description of the wheel further includes a predictive description which is a function of the wheel dynamic.

15. The method according to claim 12, wherein the correction factors of the at least one matrix are sorted by ascending slip and by ascending wheel acceleration, and wherein the at least one matrix includes a first region whose elements have a correction factor of zero.

16. The method according to claim 12, wherein the third value of the target wheel acceleration is a function of a sum of the first value and the second value.

17. The method according to claim 16, wherein the third value is a function of limiting the sum of the first value and the second value.

18. The method according to claim 12, further comprising the following steps: sensing the third value of the target wheel acceleration for at least one situation, wherein the situation includes the wheel velocity, the wheel acceleration, and a wheel dynamic; comparing the third value to a corresponding correction factor of the at least one matrix; and entering an update of the third value into a corresponding element of the at least one matrix when the slip is lower when using the third value than when using the corresponding correction factor of the at least one matrix.

19. A drive control system for a drive control of actuators of at least one wheel of a vehicle, the drive control system comprising: a signal sensing unit configured to sense a wheel velocity of the wheel and to sense a wheel acceleration and/or a wheel dynamic; a further sensing unit configured to sense a desired acceleration and a vehicle velocity of the vehicle; a state determination unit configured to determine a status description of the wheel from the wheel velocity and the wheel acceleration; an action determination unit configured to determine a first value of a target wheel acceleration from the status description, a slip of the wheel, and the desired acceleration, wherein the slip is a function of the wheel velocity and the vehicle velocity; a correction unit including at least one matrix which contains correction factors and configured to determine a second value of the target wheel acceleration; and an actuator control device configured to control the actuators of the at least one wheel based on an operation of the first value with the second value.

20. A vehicle, comprising: a drive control system for a drive control of actuators of at least one wheel of the vehicle, the drive control system including: a signal sensing unit configured to sense a wheel velocity of the wheel and to sense a wheel acceleration and/or a wheel dynamic, a further sensing unit configured to sense a desired acceleration and a vehicle velocity of the vehicle, a state determination unit configured to determine a status description of the wheel from the wheel velocity and the wheel acceleration, an action determination unit configured to determine a first value of a target wheel acceleration from the status description, a slip of the wheel, and the desired acceleration, wherein the slip is a function of the wheel velocity and the vehicle velocity, a correction unit including at least one matrix which contains correction factors and configured to determine a second value of the target wheel acceleration, and an actuator control device configured to control the actuators of the at least one wheel based on an operation of the first value with the second value.

21. A non-transitory computer-readable medium on which is stored a program element for a drive control of actuators of at least one wheel of a vehicle, the program element, when executed on a drive control system, causing the drive control system to perform the following steps: sensing a desired acceleration; sensing a vehicle velocity of the vehicle; sensing a wheel velocity of the wheel; determining a status description of the wheel from the wheel velocity and a wheel acceleration, wherein the status description includes a static description which is a function of the wheel velocity and of the wheel acceleration; determining a first value of a target wheel acceleration from the status description, a slip of the wheel, and the desired acceleration, wherein the slip is a function of the wheel velocity and the vehicle velocity; determining a second value of the target wheel acceleration from the wheel velocity, the wheel acceleration, and the slip, wherein the second value is a function of correction factors of at least one matrix; and determining a third value of the target wheel acceleration, the third value controlling the actuators of the at least one wheel, wherein the third value is a function of the first value and of the second value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows a schematic illustration of a vehicle according to one embodiment of the present invention.

[0044] FIG. 2 shows a schematic illustration of a drive control system according to one embodiment of the present invention.

[0045] FIG. 3 shows a schematic illustration of a matrix according to one embodiment of the present invention.

[0046] FIG. 4 shows a flowchart according to one embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0047] FIG. 1 shows a schematic illustration of a vehicle 100 according to one embodiment. The vehicle of the exemplary embodiment shown comprises, without restricting generality, four wheels 120 with brakes 140.

[0048] The brakes 140 are actuated by actuators 490. In one exemplary alternative embodiment, the actuators 490 can also be part of the brakes 140, for example; further embodiments are also possible. The vehicle 100 furthermore comprises actuators 480, which may be part of the powertrain, for example. The vehicle 100 furthermore comprises sensors 150 for a wheel velocity v of each wheel 120, which sensors may, for example, be arranged on the wheel 120 and/or on the axle. The sensors 150 can also provide a wheel acceleration a and/or a wheel dynamic j. Furthermore, the vehicle comprises one or more sensors 160 for a desired acceleration DrvReq, for example from a gas pedal, a joystick, an assistance system (e.g., a cruise control), and/or from further sources. In addition, the vehicle comprises one or more sensors 170 for a vehicle velocity v.sub.GND of the vehicle 100. The signals from the sensors 150, 160, 170 are passed to inputs of a drive control system 190. The signals 485, 495 from the drive control system 190 are passed to the actuators 480, 490.

[0049] FIG. 2 schematically shows details of the drive control system 190 of FIG. 1. Identical reference signs denote identical or similar components. A signal sensing unit 200 configured to sense a wheel velocity v of the wheel 120 and, optionally, to sense a wheel acceleration a and/or a wheel dynamic j, receives, from the sensors 150 for each of the wheels 120, signals 205 of the wheel velocity v of each wheel 120 and, optionally, signals of the wheel acceleration a and/or of the wheel dynamic j. If the signals a and j are not provided by the sensors 150, these signals can be formed, for example by the signal sensing unit 200. The signals v, a, j 215 are passed to a state determination unit 220 which is configured to determine a status description 225 of the wheel or of each wheel 120, from v and a, optionally also from j.

[0050] The signals 305 from the sensors 150, 160, 170 are passed to a further sensing unit 300 which is configured to sense the desired acceleration DrvReq (from the sensor 160) and a vehicle velocity v.sub.GND (from the sensor 170) of the vehicle 100. A slip s can be formed by the sensing unit 300 and/or by downstream components. The slip s can be formed for each of the wheels 120 as a function of the wheel velocity v and the vehicle velocity V.sub.GND. An action determination unit 250 determines a first value 275 of a target wheel acceleration from the status description 225, the slip s of the wheel 120 and the desired acceleration DrvReq. For example, the first value 275 can be selected from a set { accelerate, decelerate, maintain } or can comprise this set. A correction unit 360 determines a second value 375 of the target wheel acceleration from the wheel velocity v, the wheel acceleration a, and the slip s. The correction unit 360 comprises at least one matrix 350, which contains correction factors. The correction factors of the at least one matrix 350 can, for example, be sorted by ascending slip s and by ascending wheel acceleration a. Gaps (e.g., if an entry in the matrix 350 for a particular slip s and/or for a particular wheel acceleration a does not exist) in the matrix 350 can be filled by means of interpolation, for example.

[0051] The output signals 275, 375 of the action determination unit 250 and of the correction unit 360 are passed to an actuator control device 400. A summing unit 420 can sum the values of the output signals 275, 375 and/or form, for each wheel 120, a signal which is a function of the output signals 275, 375. A limiting unit 440 can limit the output signals of the summing unit 420, e.g., by means of a functional and/or plausibility check. The algorithms of these checks can, for example, take into account a maximum output of the powertrain 480 and/or of the brakes 490, 140. The algorithms of these checks can, for example, take into account functional relationships of the wheels 120, e.g., (mechanical and/or electronic) differentials. The output signals 485, 495 of the actuator control device 400 are passed to the powertrain 480 or the brakes 490, 140.

[0052] The drive control system 190 can optionally comprise a learning unit 450. In this case, the learning unit 450 can acquire one or more third values 485, 495 for at least one situation. The situation can comprise the wheel velocity v, the wheel acceleration a and, optionally, the wheel dynamic j. The learning unit 450 can compare the third value 485, 495 to the corresponding correction factor of the at least one matrix 350. Furthermore, if the slip s is lower when using the third value 485, 495 than when using the corresponding correction factor of the at least one matrix 350, an update of the third value 485, 495 can be entered into the corresponding element of the at least one matrix 350. This allows the learning unit 450 to learn from the practice of the drive control of this vehicle 100 and to thus improve the control system. Alternatively, or additionally, further options for updating the one matrix 350 can be implemented.

[0053] The components of the drive control system 190 can be realized as hardware, software, and/or from a combination of hardware and software. The components can be distributed spatially or realized in a single control device.

[0054] FIG. 3 schematically shows a matrix 350 according to one embodiment. The elements of the matrix 350 comprise correction factors that can contribute to forming the third value 375 for a respective wheel 120. The correction factors of the at least one matrix 350 are sorted by ascending slip s (e.g., horizontally) and by ascending wheel acceleration a (e.g., vertically). The matrix 350 can have a first region 351 whose elements have a correction factor of zero. The further regions of the matrix 350 can, for example, be characterized as follows: [0055] Region 352: slip s is lower, wheel acceleration is about zero; [0056] Region 353: slip s is lower, wheel acceleration is greater; [0057] Region 354: slip s is about zero, wheel acceleration is greater; [0058] Region 355: slip s is greater, wheel acceleration is greater; [0059] Region 356: slip s is greater, wheel acceleration is about zero; [0060] Region 357: slip S is greater, wheel acceleration is lower; [0061] Region 358: slip s is about zero, wheel acceleration is lower; [0062] Region 359: slip s is lower, wheel acceleration is lower.

[0063] The elements of the matrix can have an equidistant distance of the slip values and/or wheel acceleration values and/or other distance functions. Correction factors between the elements can be interpolatable.

[0064] FIG. 4 shows a flowchart 500 according to one embodiment. The method starts in a step 502. In a step 504, a desired acceleration DrvReq (see FIG. 2) is sensed. In a step 506, a vehicle velocity v.sub.GND of the vehicle 100 is sensed. In a step 508, a wheel velocity v of the wheel 120 is sensed. Steps 504, 506, 508 can be performed substantially in parallel.

[0065] In a step 510, a status description 225 of the wheel 120 is determined from the wheel velocity v and a wheel acceleration a. The status description 225 comprises a static description 226 which is a function of the wheel velocity v and the wheel acceleration a. In a step 512, a first value 275 of a target wheel acceleration is determined from the status description 225, a slip s of the wheel 120 and the desired acceleration DrvReq. Here, the slip s is a function of the wheel velocity v and the vehicle velocity v.sub.GND. In a step 514, a second value 375 of the target wheel acceleration is determined from the wheel velocity v, the wheel acceleration a and the slip s, wherein the second value is a function of correction factors of at least one matrix 350. Steps 510, 512 and step 514 can be performed substantially in parallel.

[0066] In a step 516, a third value 585, 595 of the target wheel acceleration is determined, which value controls the actuators 580, 590 of the at least one wheel 120, wherein the third value 585, 595 is a function of the first value 275 and of the second value 375. Steps 502 to 516 can be repeated regularly, e.g., periodically, e.g., every 1 ms, 2 ms, 5 ms, and/or with another periodicity or cycle time.