CN117719520A - Unit and method for determining a reference vehicle speed of a vehicle - Google Patents
Unit and method for determining a reference vehicle speed of a vehicle Download PDFInfo
- Publication number
- CN117719520A CN117719520A CN202211094322.8A CN202211094322A CN117719520A CN 117719520 A CN117719520 A CN 117719520A CN 202211094322 A CN202211094322 A CN 202211094322A CN 117719520 A CN117719520 A CN 117719520A
- Authority
- CN
- China
- Prior art keywords
- wheel
- current period
- speed
- value
- detection value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000001514 detection method Methods 0.000 claims abstract description 199
- 238000012937 correction Methods 0.000 claims abstract description 62
- 230000008859 change Effects 0.000 claims abstract description 51
- 238000006243 chemical reaction Methods 0.000 claims abstract description 36
- 230000001133 acceleration Effects 0.000 claims description 32
- 238000006073 displacement reaction Methods 0.000 claims description 15
- 238000004422 calculation algorithm Methods 0.000 claims description 13
- 238000001914 filtration Methods 0.000 claims description 11
- 230000002159 abnormal effect Effects 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000008054 signal transmission Effects 0.000 description 4
- 230000001052 transient effect Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- OIGNJSKKLXVSLS-VWUMJDOOSA-N prednisolone Chemical compound O=C1C=C[C@]2(C)[C@H]3[C@@H](O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 OIGNJSKKLXVSLS-VWUMJDOOSA-N 0.000 description 3
- XOFYZVNMUHMLCC-ZPOLXVRWSA-N prednisone Chemical compound O=C1C=C[C@]2(C)[C@H]3C(=O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 XOFYZVNMUHMLCC-ZPOLXVRWSA-N 0.000 description 3
- 241000084490 Esenbeckia delta Species 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000007306 turnover Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Landscapes
- Steering Control In Accordance With Driving Conditions (AREA)
Abstract
The present application relates to a unit and a method for determining a reference vehicle speed of a vehicle, the reference vehicle speed being suitable for calculating a desired rotation angle of a rear wheel, the unit comprising: an acquisition module; a first determination module that determines whether a wheel speed detection value of a corresponding wheel in a current period is normal based on a detection value change rate of the corresponding wheel in the current period relative to a wheel speed detection value in a previous period; a second determination module that determines a wheel speed conversion value based on a wheel speed detection value of the corresponding wheel in the current period; a correction module that corrects a wheel speed conversion value of a corresponding wheel in a current period; a third determination module that determines a reference vehicle speed magnitude in a current period based on a wheel speed correction value of each wheel in the current period; and a fourth determination module that determines a reference vehicle speed direction in the current period based on the wheel direction detection value of each wheel in the current period. The unit and the method provided by the application reduce the problem of the deflection of the rear wheels and improve the steering smoothness of the rear wheels.
Description
Technical Field
The present application relates to the field of rear-wheel steering of vehicles, and more particularly to a unit and method for determining a reference vehicle speed of a vehicle, such reference vehicle speed being suitable for calculating a desired steering angle for a rear wheel of a plurality of wheels of the vehicle.
Background
With the development of modern vehicle technology and the improvement of road conditions, the requirements for comfort, handling and safety of vehicles are increasing, and in order to improve the cornering flexibility of vehicles, the stability of straight running of vehicles, the comfort of vehicles and the like, rear-wheel follow-up steering technology is applied to vehicles. In other words, by utilizing the rear wheel follow-up steering technique, the rear wheels and the front wheels are rotated in opposite directions when the vehicle is at a low speed or has an understeer, so as to achieve the purpose of reducing the turning radius and improving the flexibility of the vehicle, and the rear wheels and the front wheels are rotated in the same direction when the vehicle is in an oversteer, particularly in a high-speed tail flick trend, so as to smoothly change lanes.
In general, an RWS (Rear Wheel Steering: rear wheel steering) control ECU (Electronic Control Unit: electronic control unit) of a vehicle acquires a vehicle speed, a steering wheel angle, a side longitudinal acceleration, a yaw rate, and the like from other relevant ECUs of the vehicle through, for example, a CAN bus for calculating a desired turning angle of a rear wheel adapted to a current running condition of the vehicle, and controls a rear wheel steering device so as to cause the rear wheel to steer to the desired turning angle. The vehicle speed from other related ECUs of the vehicle is typically an average of the wheel speed magnitudes of a plurality of wheels of the vehicle, and the wheel speed magnitudes of the respective wheels are detected by wheel speed sensors associated with the respective wheels of the plurality of wheels to generate wheel speed detection values transmitted in the form of wheel speed signals. On the one hand, there is an error in the wheel speed detection value generated by the wheel speed sensor, and on the other hand, there is a possibility that signal loss or delay occurs during transmission of the wheel speed signal, resulting in unreasonable fluctuation of the wheel speed detection value in the current period relative to the wheel speed detection value in the previous period, whereas the RWS control ECU is liable to cause abrupt change in the desired rotation angle of the rear wheel by calculating the desired rotation angle of the rear wheel based on the vehicle speed calculated based on such wheel speed detection value, reducing driving comfort, and even causing potential safety hazard.
Disclosure of Invention
It is an object of the present application to provide a unit and a method for determining a reference vehicle speed of a vehicle, which is suitable for calculating a desired turning angle of a rear wheel of a plurality of wheels for the vehicle, because such reference vehicle speed is both reasonably representative of the current driving situation of the vehicle and suppresses a desired turning angle abrupt change of the rear wheel by a stationary change of itself.
According to one aspect of the present application, there is provided a unit for determining a reference vehicle speed of a vehicle, the reference vehicle speed being adapted to calculate a desired rotation angle for a rear wheel of a plurality of wheels of the vehicle, wherein the unit comprises: an acquisition module configured to acquire a wheel speed detection value and a wheel direction detection value of a respective wheel in each cycle from a wheel speed sensor associated with the respective wheel of the plurality of wheels; a first determination module configured to determine whether a wheel speed detection value of a corresponding wheel in a current period is normal based on a detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to a wheel speed detection value in a previous period, wherein when the wheel speed detection value of the corresponding wheel in the current period is abnormal, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period; a second determination module configured to determine a wheel speed conversion value of the corresponding wheel in the current period based on the wheel speed detection value of the corresponding wheel in the current period to represent a centroid speed magnitude generated when the wheel speed of the corresponding wheel is converted to a vehicle centroid; a correction module configured to correct a wheel speed conversion value of the corresponding wheel in the current period to generate a wheel speed correction value of the corresponding wheel in the current period; a third determination module configured to determine a reference vehicle speed magnitude in a current period based on a wheel speed correction value of each wheel in the current period; and a fourth determination module configured to determine a reference vehicle speed direction in the current period based on the wheel direction detection value of each wheel in the current period.
Optionally, the acquisition module is configured to: obtaining validity values of wheel speed detection values of respective wheels in each cycle from the wheel speed sensor, and the first determination module is configured to: before determining whether the wheel speed detection value of the corresponding wheel in the current period is normal based on the detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to the wheel speed detection value of the previous period, determining whether the wheel speed detection value of the corresponding wheel in the current period is valid based on the validity value of the wheel speed detection value of the corresponding wheel in the current period, wherein when the wheel speed detection value of the corresponding wheel in the current period is invalid, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period.
Optionally, the acquisition module is configured to: obtaining a steering wheel angle detection value in each cycle from a steering wheel angle sensor associated with a steering wheel of the vehicle; and acquiring a rear wheel steering device displacement detection value in each cycle from a rear wheel steering device displacement sensor associated with a rear wheel steering device of the vehicle; and the second determination module is configured to: the front wheel rotation angle value in the current period is determined based on the steering wheel rotation angle detection value in the current period, the rear wheel rotation angle value in the current period is determined based on the rear wheel rotation device displacement detection value in the current period, and the wheel speed conversion value of the corresponding wheel in the current period is determined based on the front wheel rotation angle value in the current period, the rear wheel rotation angle value in the current period, and the wheel speed detection value of the corresponding wheel in the current period.
Optionally, the acquisition module is configured to: acquiring acceleration detection values of corresponding wheels in each cycle from the wheel speed sensor; and obtaining a yaw-rate detection value in each cycle from a yaw-rate sensor associated with a chassis of the vehicle, and the correction module is configured to: determining an acceleration conversion value of the corresponding wheel in the current period based on the acceleration detection value and the yaw rate detection value of the corresponding wheel in the current period to represent a centroid acceleration magnitude generated when the acceleration of the corresponding wheel is converted to the vehicle centroid; and correcting the wheel speed conversion value of the corresponding wheel in the current period based on the acceleration conversion value of the corresponding wheel in the current period by using a Kalman filtering algorithm.
Optionally, the correction module is configured to: the method includes determining a wheel speed predicted value of a corresponding wheel in a current period based on an acceleration conversion value of the corresponding wheel in the current period using a prediction model of a Kalman filtering algorithm, and determining a wheel speed corrected value of the corresponding wheel in the current period based on the wheel speed conversion value of the corresponding wheel in the current period and the wheel speed predicted value using an update model of the Kalman filtering algorithm, wherein the wheel speed predicted value of the corresponding wheel in the current period is taken as the wheel speed corrected value when the wheel speed detected value of the corresponding wheel in the current period cannot be acquired from the wheel speed sensor by an acquisition model.
Optionally, the third determination module is configured to: calculating a first average value of wheel speed correction values of the plurality of wheels in a current period; and determining a vehicle speed value that changes by the first average value or by the reference vehicle speed magnitude in the last period relative to an acceptable maximum vehicle speed change rate as the reference vehicle speed magnitude in the current period based on the vehicle speed change rate of the first average value relative to the reference vehicle speed magnitude in the last period.
Optionally, the third determination module is configured to: calculating a first average value of wheel speed correction values of the plurality of wheels in a current period; determining whether the wheel speed correction value of each wheel is available for determining a reference vehicle speed magnitude in the current period based on a correction value change rate of the wheel speed correction value of each wheel in the current period relative to the first average value; calculating a second average of all wheel speed correction values usable to determine a reference vehicle speed magnitude in the current period; and determining a vehicle speed value that changes by the second average value or by the reference vehicle speed magnitude in the previous cycle relative to the acceptable maximum vehicle speed change rate as the reference vehicle speed magnitude in the current cycle based on the vehicle speed change rate of the second average value relative to the reference vehicle speed magnitude in the previous cycle.
Optionally, the unit further comprises a speed limiting module configured to: when the calculated reference yaw rate based on the reference vehicle speed magnitude in the current period is larger than the yaw rate detection value in the current period multiplied by the safety coefficient, the vehicle speed value, in which the reference vehicle speed magnitude in the last period is changed with respect to the acceptable maximum vehicle speed change rate, is taken as the reference vehicle speed magnitude in the current period.
Optionally, the fourth determination module is configured to determine the reference vehicle speed direction in the current period by at least one of: when the wheel direction detection values of three or more than three wheels in the current period are positive, judging that the reference vehicle speed direction in the current period is positive; when the wheel direction detection values of three or more than three wheels in the current period are inverse, judging that the reference vehicle speed direction in the current period is inverse; when the wheel direction detection value of two wheels in the current period is positive and the wheel direction detection value of the other two wheels in the current period is negative, using the reference vehicle speed direction in the previous period as the reference vehicle speed direction in the current period; and when the acquisition module cannot acquire the wheel direction detection value of the corresponding wheel in the current period from the wheel speed sensor, taking the wheel direction detection value of the corresponding wheel in the previous period as the wheel direction detection value of the corresponding wheel in the current period.
According to another aspect of the present application, there is provided a method for determining a reference vehicle speed of a vehicle, the reference vehicle speed being adapted to calculating a desired rotation angle for a rear wheel of a plurality of wheels of the vehicle, the method optionally being performed with the above-mentioned unit for determining a reference vehicle speed of a vehicle, wherein the method comprises: obtaining a wheel speed detection value and a wheel direction detection value of a corresponding wheel in each cycle from a wheel speed sensor associated with the corresponding wheel of the plurality of wheels; determining whether the wheel speed detection value of the corresponding wheel in the current period is normal based on the detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to the wheel speed detection value of the previous period, wherein when the wheel speed detection value of the corresponding wheel in the current period is abnormal, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period; determining a wheel speed conversion value of the corresponding wheel in the current period based on the wheel speed detection value of the corresponding wheel in the current period to represent a centroid speed magnitude generated when the wheel speed of the corresponding wheel is converted to a vehicle centroid; correcting the wheel speed conversion value of the corresponding wheel in the current period to generate a wheel speed correction value of the corresponding wheel in the current period; determining a reference vehicle speed in the current period based on the wheel speed correction value of each wheel in the current period; and determining a reference vehicle speed direction in the current period based on the wheel direction detection value of each wheel in the current period.
According to the unit and the method for determining the reference vehicle speed of the vehicle, under the condition that the wheel speed detection value fluctuates due to errors, signal loss or delay of detection of the wheel speed sensor, the reference vehicle speed can still be ensured to be suitable for calculating the expected rotation angle of the rear wheel without obvious step, the deflection problem of the rear wheel caused by the expected rotation angle is reduced, the steering smoothness of the rear wheel is improved, and the safety of the whole vehicle is ensured.
Other features of the present application and its advantages will become apparent from the following detailed description of exemplary embodiments of the present application, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.
FIG. 1 is a schematic block diagram of a unit for determining a reference vehicle speed of a vehicle according to one embodiment of the present application.
FIG. 2 is a schematic illustration of a vehicle having a unit for determining a reference vehicle speed of the vehicle and associated sensors according to one embodiment of the present application.
Fig. 3 is a determination flowchart of a slip determination module of a unit for calculating a reference vehicle speed of a vehicle according to one embodiment of the present application.
Fig. 4 is a judgment flowchart of the validity judgment module of the unit for calculating the reference vehicle speed of the vehicle according to one embodiment of the present application.
Fig. 5 is a schematic diagram of the calculation principle of the second determination module and the correction module of the unit for calculating the reference vehicle speed of the vehicle according to one embodiment of the present application.
FIG. 6 is a flowchart of a method for calculating a reference vehicle speed for a vehicle according to one embodiment of the present application.
Detailed Description
Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.
Techniques, apparatus and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.
It should be noted that: the various variables and their values described herein are each transformed in the form of signals or data in the various modules, units, and devices to transfer the various variables and their values between the various modules, units, and devices, and thus, for the sake of brevity, the variables and their values themselves will be referred to directly below without reference to the signals or data representing them.
In general, the unit 12 for determining the reference vehicle speed of the vehicle may be integrated in the RWS control ECU 13 as part of the RWS control ECU 13, and the reference vehicle speed will subsequently be suitable for calculating a plurality of wheels, e.g., four wheels (i.e., front wheel: left front wheel W 1 And right front wheel W 2 The method comprises the steps of carrying out a first treatment on the surface of the And a rear wheel: left rear wheel W 3 And right rear wheel W 4 ) The desired rotation angle of the rear wheel (i.e., the rotation angle to be applied).
Referring to fig. 1, the unit 12 generally includes an acquisition module 18, a first determination module 20, a second determination module 22, a correction module 24, a third determination module 26, and a fourth determination module 28 that may communicate.
The acquisition module 18 may be configured to acquire detection values of relevant variables for determining the reference vehicle speed in each cycle from sensors mounted on relevant components of the vehicle through, for example, a CAN bus.
Referring to fig. 2, these sensors, not shown in the drawings, include: and the left front wheel W 1 An associated wheel speed sensor for detecting the left front wheel W in each cycle 1 To generate a wheel speed detection value V 1,detected And its validity value VA 1 Detect left front wheel W 1 To produce an acceleration detection value A 1,detected And detects the left front wheel W 1 To generate a wheel direction detection value D 1 The method comprises the steps of carrying out a first treatment on the surface of the And the right front wheel W 2 An associated wheel speed sensor for detecting the right front wheel W in each cycle 2 To generate a wheel speed detection value V 2,detected And its validity value VA 2 Detect right front wheel W 2 To produce an acceleration detection value A 2,detected And detects the right front wheel W 2 To generate a wheel direction detection value D 2 The method comprises the steps of carrying out a first treatment on the surface of the And the left rear wheel W 3 An associated wheel speed sensor for detecting the left rear wheel W in each cycle 3 To generate a wheel speed detection value V 3,detected And its validity value VA 3 Detect left rear wheel W 3 To produce an acceleration detection value A 3,detected And detects the left rear wheel W 3 To generate a wheel direction detection value D 3 The method comprises the steps of carrying out a first treatment on the surface of the And right rear wheel W 4 An associated wheel speed sensor for detecting the right rear wheel W in each cycle 4 To generate a wheel speed detection value V 4,detected And its validity value VA 4 Detect right rear wheel W 4 To produce an acceleration detection value A 4,detected And detects the right rear wheel W 4 To generate a wheel direction detection value D 4 The method comprises the steps of carrying out a first treatment on the surface of the A steering wheel angle sensor associated with the steering wheel 14 of the vehicle for detecting the angle of rotation of the steering wheel 14 in each cycle to produce a steering wheel angle detection value delta ang Wherein the angle of rotation of the steering wheel 14 is generally due to an operator applying torque to the steering wheel 14 to cause the squareIs deflected relative to its initial position by the steering wheel 14, in which initial position the steering wheel 14 causes the front wheel W 1 、W 2 Returning, in the case where there is a rotation angle of the steering wheel 14, the steering wheel 14 causes the front wheel W to rotate 1 、W 2 Turning; a rear-wheel steering device displacement sensor associated with the rear-wheel steering device 16 of the vehicle for detecting displacement of the rear-wheel steering device 16 in each cycle to produce a rear-wheel steering device 16 displacement detection value y, wherein the displacement of the rear-wheel steering device 16 directly or indirectly refers to a displacement distance of an execution member of the rear-wheel steering device 16 relative to a reference zero position thereof at which the rear-wheel steering device 16 is caused to return the rear wheel, and in the presence of the displacement of the rear-wheel steering device 16, the rear-wheel steering device 16 is caused to return the rear wheel W 3 、W 4 Turning; and a yaw-rate sensor associated with the chassis 17 of the vehicle for detecting a yaw-rate of the vehicle in each cycle to generate a yaw-rate detection value Y aw,detected 。
For simplicity, the subscript i hereinafter denotes the subscripts 1-4 associated with the respective wheel to denote any one of the four wheels.
Returning to fig. 1, the first determination module 20 may include a slip determination module 20a and an optional validity determination module 20b.
Referring to fig. 3, the slip determination module 20a is configured to be based on the corresponding wheel W i Wheel speed detection value V in current period i,detected,T With respect to the wheel speed detection value V in the previous cycle i,detected,T-1 To determine the corresponding wheel W i Wheel speed detection value V in current period i,detected,T Whether or not it is normal, where, when the corresponding wheel W i Wheel speed detection value V in current period i,detected,T When it is abnormal, the wheel speed detection value V of the corresponding wheel in the previous cycle is used i,detected,T-1 As the corresponding wheel W i Wheel speed detection value V in current period i,detected,T I.e. such that V i,detected,T ＝V i,detected,T-1 . In fig. 3, N is the number of wheels.
For example, when the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T With respect to the wheel speed detection value V in the previous cycle 1,detected,T-1 The detected value change rate of (V) 1,detected,T -V 1,detected,T-1 )|/V 1,detected,T-1 When the left front wheel W is smaller than or equal to a first threshold value delta D, the left front wheel W is judged 1 The wheel speed in the current period is normal; when the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T With respect to the wheel speed detection value V in the previous cycle 1,detected,T-1 When the detected value change rate of (2) is greater than the first threshold value DeltaD, the left front wheel W is judged 1 Slip or left front wheel W occurs in the current cycle 1 Wheel speed detection value V in current period 1,detected,T There is abnormal fluctuation, therefore, in the left front wheel W 1 Normal wheel speed detection value V in last cycle 1,detected,T-1 As_pdate\replace\cover left front wheel W 1 Wheel speed detection value V in current period 1,detected,T I.e. such that V 1,detected,T ＝V 1,detected,T-1 . For example, the magnitude of Δd may be calibrated by real vehicle testing. The rate of change of the detected value is the corresponding wheel W i Wheel speed detection value V in current period i,detected,T Subtracting the wheel speed detection value V in the previous cycle i,detected,T-1 Divided by the absolute value of the difference of the corresponding wheel W i Wheel speed detection value V in last cycle i,detected,T-1 。
In addition, if all the wheels have wheel speed detection value V in the current cycle i,detected,T With respect to the wheel speed detection value V in the previous cycle i,detected,T-1 If the detected value change rates of (a) are greater than the first threshold value Δd, indicating that all wheels may slip, the unit 12 may send a failure signal to a failure processing unit (not shown) of the RWS control ECU 13 to cause the RWS control ECU 13 to control the rear-wheel steering device 16 to cause the rear wheels W 3 、W 4 Is returned to normal and remains locked because in this case it is necessary to ensure that the wheels have sufficient drive force to leave a slip zone where all wheels slip.
Referring to fig. 4, the validity judgment module 20b may be executed before the slip judgment module 20a is executed, the validity judgment module 20b being configured to be based on the corresponding wheel W i Wheel speed detection value V in current period i,detected,T Validity value VA of (a) i,T To determine the corresponding wheel W i Wheel speed detection value V in current period i,detected,T Whether or not to be effective, where, when the corresponding wheel W i Wheel speed detection value V in current period i,detected,T When it is invalid, the corresponding wheel W is used i Wheel speed detection value V in last cycle i,detected,T-1 As the corresponding wheel W i Wheel speed detection value V in current period i,detected,T . In fig. 4, N is the number of wheels.
For example, when the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T When inactive, it means the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Is not suitable for use, in particular for calculating a reference vehicle speed, and is driven by the left front wheel W 1 Wheel speed detection value V in last cycle 1,detected,T-1 As the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T I.e. such that V 1,detected,T ＝V 1,detected,T-1 . Here, the left front wheel W should be 1 Wheel speed detection value V in current period 1,detected,T Cases considered invalid include: left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Validity value VA of (a) 1,T Lost during signal transmission, but left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Is not necessarily lost in the course of the signal transmission; or left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Validity value VA of (a) 1,T For example 0 instead of 1 to represent the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T There is an error or a serious error.
In addition, when the left front wheel W 1 Wheel speed detection value V of (2) 1,detected,T Has been ineffective asLast for a fault tolerance time T 1 When the unit 12 can send a failure signal to the failure processing unit of the RWS control ECU 13 to cause the RWS control ECU 13 to control the rear-wheel steering device 16 to cause the rear wheels W 3 、W 4 Return to normal and remain locked. In addition, at fault tolerance time T 1 In, if all wheels have wheel speed detection value V in current period i,detected,T Are all invalid, the reference vehicle speed magnitude V calculated in the previous cycle by the direct-use unit 12 O,T-1 I.e. such that V O,T ＝V O,T-1 。
It will be appreciated that, for example, when the slip determination module 20a is determining the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T In the case of being invalid, the left front wheel W 1 Wheel speed detection value V in last cycle 1,detected,T-1 As the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T At the time, the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T With respect to the wheel speed detection value V in the previous cycle 1,detected,T-1 The detected value change rate of (a) will be zero, i.e. less than Δd, and the validity judgment module 20b will judge the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Is normal. Therefore, the judgment of the slip judgment module 20a and the judgment of the validity judgment module 20b do not conflict with each other.
The second determination module 22 is configured to be based on the respective wheel W i Wheel speed detection value V in current period i,detected,T To determine the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T Wherein the wheel speed conversion value is represented in the corresponding wheel W i The magnitude of the centroid velocity generated when the wheel speed of the vehicle is converted to the centroid.
For example, the vehicle may be depicted as a simplified vehicle model as a planar rigid body as shown in fig. 5, the simplified vehicle model reasonably including: from the left front wheel W, e.g. synchronously steered, as shown in figure 2 1 And right front wheel W 2 Synthetic one simplified front wheel SW 1 Said one simplified front wheelSW 1 Is positioned at the center of the left front wheel W 1 Is provided with a wheel center and a right front wheel W 2 The center of the first line segment of the wheel center; from the left rear wheel W, e.g. synchronously steered, as shown in figure 2 3 And right rear wheel W 4 Synthetic one simplified rear wheel SW 2 Said one simplified rear wheel SW 2 The wheel center is positioned at the left rear wheel W 3 Is provided with a wheel center and a right rear wheel W 4 The center of the second line segment of the wheel center; located at the one simplified front wheel SW 1 And said one simplified rear wheel SW 2 A vehicle centroid C therebetween, for example, the vehicle centroid C may be located in connection with the one simplified front wheel SW 1 Is provided, and the one simplified rear wheel SW 2 Third line segment L of the wheel center 3 And (3) upper part.
The unit 12 can obtain the steering wheel angle detection value delta in the current period from the steering wheel angle sensor ang,T To determine the front wheel rotation angle value delta in the current period SF,T For example, it is possible to use a preset transmission ratio K between the angle of rotation of the steering wheel 14 and the angle of rotation of the front wheel 1 I.e. delta SF,T ＝δ ang,T ×K 1 . Front wheel angle delta SF,T May refer to simplifying the front wheels SW when simplifying the vehicle turning 1 Relative to the third line L 3 Included angle of forward extending direction to determine simplified front wheel SW 1 In the wheel speed direction of (a), herein, the front wheel SW is simplified 1 The wheel speed direction of (a) may refer to the left and right front wheels W 1 、W 2 The wheel speed direction of both.
The unit 12 can detect the value y of the displacement of the rear-wheel steering device 16 in the current period by acquiring from the rear-wheel steering device displacement sensor T To determine the rear wheel steering angle value delta in the current period SR,T For example, the preset ratio K between the displacement of the rear-wheel steering device 16 and the rear-wheel steering angle may be used 2 I.e. delta SR,T ＝y T ×K 2 . Rear wheel steering angle delta SR May refer to simplifying rear wheels SW when simplifying a vehicle turn 2 Relative to the third line L 3 Included angle of forward extending direction to determine simplified rear wheel SW 2 In the wheel speed direction of (a), herein, the rear wheel SW is simplified 2 The wheel speed direction of (a) may refer to the left and right rear wheels W 3 、W 4 The wheel speed direction of both.
Then, based on the simplified front wheel SW 1 Wheel speed direction of (1) and simplified rear wheel SW 2 The wheel speed direction of (c) may determine the transient turning center O at the time of simplifying the turning of the vehicle. In other words, the transient turning center O is two straight lines H 1 、H 2 Is a straight line H 1 Through a simplified front wheel SW 1 Is connected with the simplified front wheel SW 1 Extending perpendicularly to the wheel speed direction of the wheel, another straight line H 2 Through a simplified rear wheel SW 2 Is connected with the simplified rear wheel SW 2 Extending perpendicularly in the wheel speed direction. Then, a fourth line segment L connecting the intersection point and the vehicle centroid C 4 As transient turning radius. The third line segment L can then be known based on the specific vehicle design 3 Length of (C), vehicle centroid C and simplified front wheel SW 1 Distance a of the center of wheel of (a), vehicle center of mass C and simplified rear wheel SW 2 Thus, the direction of the centroid velocity tangential to the transient turning radius of the vehicle centroid C and the simplification of the front wheel SW can be determined from the triangle geometry 1 Wheel speed direction of (1) and simplified rear wheel SW 2 Included angle delta of wheel speed direction relative to direction of centroid speed of vehicle centroid C C,T 。
Then, according to the speed analysis method of theoretical mechanics to the plane rigid body, the corresponding wheel W i Wheel speed detection value V in current period i,detected,T In a direction of mass-center speed scaled to the mass center C of the vehicle to determine the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T 。
The correction module 24 is configured to correct the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T To produce the corresponding wheel W i Wheel speed correction value V in current period i,modified,T 。
Optionally, the correction module 24 is configured to be based on the slave respective wheel W i Corresponding wheel W acquired by wheel speed sensor i At the present timeAcceleration detection value A in previous cycle i,detected,T And from yaw rate sensor S 7 The obtained yaw-rate detection value Y aw,detected,T To determine the corresponding wheel W i Acceleration conversion value A in current period i,converted,T Wherein the acceleration conversion value is represented in the corresponding wheel W i The magnitude of the centroid acceleration that occurs when the acceleration of (a) is converted to the centroid of the vehicle.
For example, referring still to fig. 5, according to the method of analyzing acceleration of theoretical mechanics to planar rigid body, the corresponding wheel W i The corresponding wheel W should be considered when the acceleration of (C) is converted to the vehicle centroid C i Acceleration vector and vehicle centroid C around corresponding wheel W i Is a rotational acceleration vector omega of the wheel center R Wherein, can be according to the corresponding wheel W i Acceleration detection value A in current period i,detected,T Angle delta of front wheel SF,T Rear wheel steering angle delta SR,T To determine the corresponding wheel W i And wherein the detection value Y can be based on the yaw-rate aw,detected,T Center of mass C of vehicle and simplified front wheel SW 1 Distance a of the center of wheel of (a), vehicle center of mass C and simplified rear wheel SW 2 To determine the distance b of the centre of mass C of the vehicle around the corresponding wheel W i Is a rotational acceleration vector omega of the wheel center R 。
Optionally, the correction module 24 is configured to utilize a Kalman filtering algorithm based on the respective wheel W i Acceleration conversion value A in current period i,converted,T To correct the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T To produce the corresponding wheel W i Wheel speed correction value V in current period i,modified,T 。
Alternatively, the prediction model based on the corresponding wheel W using the Kalman filtering algorithm shown in the following equation (1) i Acceleration conversion value A in current period i,converted,T To determine the corresponding wheel W i Wheel speed predictive value V in current period i,predicted,T ，
Wherein,representing the corresponding wheel W i Wheel speed value corrected by Kalman filtering algorithm in last cycle, i.e. V i,predicted,T -1；V at Representing the corresponding wheel W i The acceleration conversion value in the current period, i.e. A i,converted,T ；P t-1 Representing the corresponding wheel W i Wheel speed covariance of last cycle and covariance of random process error Q; A. b is a coefficient matrix, which can be calibrated by, for example, empirical and real vehicle testing. Accordingly, the corresponding wheel W can be predicted using the prediction model of the Kalman filtering algorithm i Wheel speed average value in current period +.>As the corresponding wheel W i Wheel speed predictive value V in current period i,predicted,T And predicting the corresponding wheel W i Wheel speed covariance in current period +.>
Then, an updated model of the Kalman filtering algorithm using the following formula (2) is based on the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T And wheel speed predictive value V i,predicted,T To determine the corresponding wheel W i The wheel speed correction value in the current period,
wherein R represents the covariance of the measurement error; k (K) t Representing a kalman gain coefficient; y is t ＝CV t Wherein c=1, v t Representing the corresponding wheel W i In the current periodWheel speed conversion value V of (2) i,converted,T The method comprises the steps of carrying out a first treatment on the surface of the I is an identity matrix. Accordingly, the corresponding wheel W can be iteratively updated using the update model of the kalman filter algorithm i Wheel speed average in current periodAs the corresponding wheel W i Wheel speed correction value V in current period i,modified,T Iteratively updating the corresponding wheel W i Wheel speed covariance P in current period t To calculate a wheel speed correction value taking into account a random error and a wheel speed sensor measurement error.
When the acquisition module 18 cannot acquire the corresponding wheel W from the wheel speed sensor i Wheel speed detection value V in current period i,detected,T When, for example, the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T May be lost during the transmission of the signal, but the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Validity value VA of (a) 1,detected,T When it is not necessarily lost during the transmission of the signal, the unit 12 will set the covariance r=0 of the measurement error, for example, to adjust the kalman gain factor K t Is 1 and y t V, i.e t Due to the left front wheel W 1 Wheel speed detection value V in current period 1,detected,T Lost to 0 during signal transmission, so that the left front wheel W 1 Wheel speed average in current period0, in this case, the left front wheel W 1 Wheel speed correction value V in current period 1,modified,T I.e. the left front wheel W calculated from the predictive model of the kalman filter algorithm 1 Wheel speed predictive value V in current period i,predicted,T Representation, i.e. V 1,modified,T ＝V i,predicted,T 。
In addition, if the left front wheel W cannot be acquired by the acquisition module 18 1 Wheel speed detection value V in current period 1,detected,T Has already been provided withLast for a fault tolerance time T 2 The unit 12 may send a failure signal to the failure processing unit of the RWS control ECU 13 to cause the RWS control ECU 13 to control the rear-wheel steering device 16 to cause the rear wheels W 3 、W 4 Return to normal and remain locked.
The third determination module 26 is configured to be based on each wheel W i Wheel speed correction value V in current period i,modified,T To determine the reference vehicle speed magnitude V in the current period O,T 。
Returning to FIG. 1, the third determination module 26 includes an optional available wheel speed determination module 26a and a first speed limit module 26b.
The first speed limit module 26b is configured to: calculating wheel speed correction value V of multiple wheels in current period i,modified,T Is the first average value N of (2) 1 I.e. N 1 ＝(V 1,modified,T +V 2,modified,T +V 3,modified,T +V 4,modified,T ) 4; based on the first average value N 1 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 Vehicle speed change rate of (N) 1 -V O,T-1 )|/V O,T-1 To determine a first average value N 1 Or at the reference vehicle speed magnitude V in the previous cycle O,T-1 The vehicle speed value changed with respect to the acceptable maximum vehicle speed change rate is taken as the reference vehicle speed magnitude V in the current period O,T 。
For example, when the first average value N 1 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 Vehicle speed change rate of (N) 1 -V O,T-1 )|/V O,T-1 When the vehicle speed is equal to or lower than the second threshold value deltae, that is, equal to or lower than the acceptable maximum vehicle speed change rate, this means that the vehicle speed is represented by the first average value N 1 As the reference vehicle speed magnitude V in the current period O,T Is safe; when the first average value N 1 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 When the speed change rate of the vehicle is greater than the second threshold value delta E, the reference speed V in the last period is set according to whether the vehicle is accelerating or decelerating O,T-1 Adding and subtracting the reference vehicle speed V in the last period O,T-1 Multiplied byThe vehicle speed value of the second threshold value deltae is used as the reference vehicle speed magnitude V in the current period O,T I.e. V O,T ＝V O,T-1 X (1±Δe), thereby preventing abrupt change in the desired rotation angle of the rear wheels due to a step in the reference vehicle speed. The vehicle speed change rate is the first average value N 1 Subtracting the reference vehicle speed V in the previous cycle O,T-1 Divided by the reference vehicle speed V in the previous cycle O,T-1 . It is noted that the second threshold ΔE is dependent on the different vehicle speeds, i.e. the different reference vehicle speed magnitudes V in the last cycle O,T-1 A change occurs.
In addition, the optional available wheel speed determination module 26a is configured to be able to be based on each wheel W in advance i Wheel speed correction value V in current period i,modified,T Relative to the first average value N 1 Determining the rate of change of correction value for each wheel W i Whether or not the wheel speed correction value of (2) can be used to determine the reference vehicle speed magnitude V in the current period O,T The method comprises the steps of carrying out a first treatment on the surface of the Calculating all reference vehicle speed magnitudes V available for determining a current period O,T Second average value N of wheel speed correction values of (2) 2 The method comprises the steps of carrying out a first treatment on the surface of the Based on the second average value N 2 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 Is determined at a second average value N by reference to the rate of change of vehicle speed 2 Or at the reference vehicle speed magnitude V in the previous cycle O,T-1 The vehicle speed value changed with respect to the acceptable maximum vehicle speed change rate is taken as the reference vehicle speed magnitude V in the current period O,T 。
For example, when the left front wheel W 1 Wheel speed correction value V in current period 1,modified,T Relative to the first average value N 1 Correction value change rate (V) 1,modified,T -N 1 )|/N 1 When the left front wheel W is smaller than or equal to a third threshold value delta F, the left front wheel W is judged 1 Is a wheel speed correction value V 1,modified,T Can be used to determine the reference vehicle speed magnitude V in the current period O,T The method comprises the steps of carrying out a first treatment on the surface of the When the left front wheel W 1 Wheel speed correction value V in current period 1,modified,T Relative to the first average value N 1 When the change rate of the correction value is greater than the third threshold value delta F, the left part is judgedFront wheel W 1 Is a wheel speed correction value V 1,modified,T Is not usable for determining the reference vehicle speed magnitude V in the current period O,T . The rate of change of the correction value is the corresponding wheel W i Wheel speed correction value V in current period i,modified,T Subtracting the first average value N 1 Divided by the first average N 1 。
When the wheel speed correction value of only one wheel is relative to the first average value N 1 When the change rate of the correction value of (2) is larger than the third threshold value delta F, calculating a second average value N by using the average value of the wheel speed correction values of the other three wheel speeds 2 . Alternatively, when the wheel speed correction values of two or more wheels are relative to the first average N 1 If the rate of change of the correction value of (a) is greater than the third threshold value deltaf, the reference vehicle speed V calculated in the previous cycle by the direct-use unit 12 is used O,T-1 I.e. V O,T ＝V O,T-1 As this means that there are more wheels that are about to slip severely.
Then, when the second average value N 2 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 Vehicle speed change rate of (N) 2 -V O,T-1 )|/V O,T-1 When the average value is less than or equal to a second threshold value delta E, the average value N is the second average value N 2 As the reference vehicle speed magnitude V in the current period O,T The method comprises the steps of carrying out a first treatment on the surface of the When the second average value N 2 Relative to the reference vehicle speed magnitude V in the last cycle O,T-1 When the speed change rate of the vehicle is greater than the second threshold value delta E, the reference speed V in the last period is set according to whether the vehicle is accelerating or decelerating O,T-1 Adding and subtracting the reference vehicle speed V in the last period O,T-1 The vehicle speed value multiplied by the second threshold value deltae is used as the reference vehicle speed magnitude V in the current period O,T I.e. V O,T ＝V O,T-1 X (1±Δe), thereby preventing abrupt change in the desired rotation angle of the rear wheels due to a step in the reference vehicle speed. The vehicle speed change rate is the second average value N 2 Subtracting the reference vehicle speed V in the previous cycle O,T-1 Divided by the reference vehicle speed V in the previous cycle O,T-1 。
Optionally, unit 12 may also include a second speed limit module 30 executed after first speed limit module 26b configured to further verify a reference vehicle speed magnitude V in the current period based on a kinetic model as shown in equations (3) - (5) below O,T Determining whether a desired rotation angle of the rear wheel is safe and reliable:
wherein alpha is i The slip angle of the four wheels; k (k) i Tire cornering stiffness for four wheels; beta is the slip angle of the vehicle centroid; gamma is the yaw rate to be calculated; u (u) c Is the driving speed, namely the reference speed V in the current period O,T Is a longitudinal component of (2); m is the mass of the vehicle; a and b are the distances of the vehicle centroid and the front and rear axles, respectively, i.e. the vehicle centroid and the simplified front wheel SW as described above 1 Distance a of the center of wheel of (a), and center of mass of vehicle and simplified rear wheel SW 2 Is the distance b of the wheel center; i is the rotational inertia of the vehicle around a vertical axis; m is yaw moment.
M can be calculated by formula (4):
M＝(c/2)(F x1 -F x2 +F x3 -F x4 ) (4)
wherein F is xi For longitudinal forces of four wheels, the driving force distribution value of the whole vehicle power driving module derived from IMCU (intelligent motion control unit 12:Intelligent Motion Control Unit) associated with the driving motor, c is the left front wheel W 1 Is provided with a wheel center and a right front wheel W 2 Is the distance between the wheel centers.
Slip angle alpha of four wheels i The relationship with the steering angle can be expressed by the formula (5):
wherein V is the lateral speed of the vehicle, namely the reference vehicle speed V in the current period O,T Side of (2)A directional component; delta i Is the corner of four wheels.
For convenience of verification, it is assumed that the vehicle is running at a constant speed in steady state in the current period, i.eAt the same time v=0, β=0 can be ensured, and therefore, the reference vehicle speed magnitude V in the current period can be based O,T Reversely calculating a reference yaw rate Y, comparing whether the calculated reference yaw rate Y is greater than a yaw rate detection value Y in the current period aw,detected,T Multiplying by a safety factor delta G, when gamma is less than or equal to Y aw,detected,T X ΔG, the reference vehicle speed V in the current period is determined O,T The reliability is high, and the method can be used for calculating the expected rotation angle of the rear wheel. When gamma > Y aw,detected,T X ΔG, the reference vehicle speed V in the current period is determined O,T The calculation of the desired rotation angle of the rear wheels may cause the vehicle to turn too much so as to turn over, in this case, at the reference vehicle speed magnitude V in the last cycle O,T-1 The vehicle speed value changed with respect to the acceptable maximum vehicle speed change rate is taken as the reference vehicle speed magnitude V in the current period O,T I.e. V O,T ＝V O,T-1 ×(1±ΔE)。
It will be appreciated that, for example, when the first speed limit module 26b is determining the reference vehicle speed V in the previous cycle O,T-1 The vehicle speed value changed with respect to the acceptable maximum vehicle speed change rate is taken as the reference vehicle speed magnitude V in the current period O,T The second speed limit module 30 will determine the reference vehicle speed V in the current period O,T Can be used to calculate the desired rotation angle of the rear wheel. Therefore, the judgment of the first speed limit module 26b and the judgment of the second speed limit module 30 do not conflict with each other.
The fourth determination module 28 is configured to, on a per wheel W basis i Determining a reference vehicle speed direction D in a current period from a wheel direction detection value Di in the current period O,T 。
For example, the fourth determination module 28 is configured to determine the reference vehicle speed direction D in the current period by at least one of O,T : when a plurality of wheels W i Wheel direction detection value D of three or more wheels in the current cycle i,T For positive, judge the reference vehicle speed direction D in the current period O , T Is positive; wheel direction detection value D when three or more than three wheels among the plurality of wheels are in the current cycle i,T If the vehicle speed is the inverse value, judging the reference vehicle speed direction D in the current period O,T Is the opposite; when a plurality of wheels W i Wheel direction detection value D of two wheels in current cycle i,T Positive and the wheel direction detection value D of the other two wheels in the current period i,T In the reverse case, the direct-use unit 12 calculates the reference vehicle speed direction D in the previous cycle O,T-1 D is O,T ＝D O,T-1 The method comprises the steps of carrying out a first treatment on the surface of the When corresponding wheel W i Wheel direction detection value D in current period i Lost during signal transmission such that the acquisition module 18 cannot acquire the corresponding wheel W from the wheel speed sensor i Wheel direction detection value D in current period i,T When the corresponding wheel W is directly used i Wheel direction detection value D in last cycle i,T-1 Namely D i,T ＝D i,T-1 The method comprises the steps of carrying out a first treatment on the surface of the When the acquisition module 18 cannot acquire the corresponding wheel W from the wheel speed sensor i Wheel direction detection value D in current period i,T Has been continued for a fault tolerance time T 3 When the unit 12 can send a failure signal to the failure processing unit of the RWS control ECU 13 to cause the RWS control ECU 13 to control the rear-wheel steering device 16 to cause the rear wheels W 3 、W 4 Return to normal and remain locked.
Referring to fig. 6, the method for determining the reference vehicle speed of the vehicle accordingly comprises the steps of:
s1001. from the corresponding wheel W of the plurality of wheels i The associated wheel speed sensor acquires the corresponding wheel W i Wheel speed detection value V in each cycle i,detected,T And wheel direction detection value D i,T ；
S1002 based on corresponding wheel W i Wheel speed detection value V in current period i,detected,T With respect to the wheel speed detection value V in the previous cycle i,detected,T-1 Is detected by (a)Value change rate to determine corresponding wheel W i Wheel speed detection value V in current period i,detected,T Whether or not it is normal, where, when the corresponding wheel W i Wheel speed detection value V in current period i,detected,T In case of abnormality, the corresponding wheel W i Wheel speed detection value V in last cycle i,detected,T-1 As a wheel speed detection value V of the corresponding wheel in the current cycle i,detected,T ；
S1003 based on corresponding wheel W i Wheel speed detection value V in current period i,detected,T To determine the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T To indicate that the corresponding wheel W i The mass center speed magnitude generated when the wheel speed of the vehicle is converted to the mass center;
s1004, correcting the corresponding wheel W i Wheel speed conversion value V in current period i,converted,T To produce the corresponding wheel W i Wheel speed correction value V in current period i,modified,T ；
S1005 based on each wheel W i Wheel speed correction value V in current period i,modified,T To determine the reference vehicle speed magnitude V in the current period O,T The method comprises the steps of carrying out a first treatment on the surface of the And
s1006 based on each wheel W i Wheel direction detection value D in current period i,T To determine the reference vehicle speed direction D in the current period O,T 。
The method for determining a reference vehicle speed of a vehicle provided in the present application is intended to be performed with a unit for determining a reference vehicle speed of a vehicle, so that the features of the unit and the features of the method described herein may correspond to each other, be combined, and be interchanged.
In addition, the unit 12 for determining the reference vehicle speed of the vehicle and the respective sensors described above actually each include a memory and a processor. In one aspect, the memory may store various executable instructions and parameters thereof. The memory may include an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of memory include: portable computer disks, hard disks, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static Random Access Memory (SRAM), portable compact disk read-only memory (CD-ROM), digital Versatile Disks (DVD), memory sticks, floppy disks, mechanical coding devices, punch cards or in-groove structures such as punch cards or grooves having instructions stored thereon, and any suitable combination of the foregoing. On the other hand, when the executable instructions and parameters thereof are executed by a processor, means are produced for accomplishing the functions/acts specified in the steps described in the specification and flowchart and/or block diagram block or blocks in the figures.
The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of units, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based units which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. It is well known to those skilled in the art that implementation by hardware, implementation by software, and implementation by a combination of software and hardware are all equivalent.
Although some specific embodiments of the present application have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present application. The scope of the application is defined by the appended claims.
Claims (10)
1. A unit (12) for determining a reference vehicle speed of a vehicle, the reference vehicle speed being adapted to calculating a desired rotation angle for a rear wheel of a plurality of wheels of the vehicle, wherein the unit (12) comprises:
an acquisition module (18) configured to acquire a wheel speed detection value and a wheel direction detection value of a respective wheel in each cycle from a wheel speed sensor associated with the respective wheel of the plurality of wheels;
a first determination module (20) configured to determine whether the wheel speed detection value of the corresponding wheel in the current period is normal based on a detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to the wheel speed detection value of the previous period, wherein when the wheel speed detection value of the corresponding wheel in the current period is abnormal, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period;
A second determination module (22) configured to determine a wheel speed conversion value of the corresponding wheel in the current period based on the wheel speed detection value of the corresponding wheel in the current period to represent a centroid speed magnitude generated when the wheel speed of the corresponding wheel is converted to the vehicle centroid;
a correction module (24) configured to correct the wheel speed conversion value of the corresponding wheel in the current period to generate a wheel speed correction value of the corresponding wheel in the current period;
a third determination module (26) configured to determine a reference vehicle speed magnitude in a current period based on a wheel speed correction value of each wheel in the current period; and
a fourth determination module (28) is configured to determine a reference vehicle speed direction in the current period based on the wheel direction detection value of each wheel in the current period.
2. The unit (12) of claim 1, wherein the acquisition module (18) is configured to:
acquiring validity values of wheel speed detection values of respective wheels in each cycle from the wheel speed sensor, and
the first determination module (20) is configured to:
before determining whether the wheel speed detection value of the corresponding wheel in the current period is normal based on the detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to the wheel speed detection value of the previous period, determining whether the wheel speed detection value of the corresponding wheel in the current period is valid based on the validity value of the wheel speed detection value of the corresponding wheel in the current period, wherein when the wheel speed detection value of the corresponding wheel in the current period is invalid, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period.
3. The unit (12) according to claim 1 or 2, wherein the acquisition module (18) is configured to:
obtaining a steering wheel angle detection value in each cycle from a steering wheel angle sensor associated with a steering wheel (14) of the vehicle; and
acquiring a rear-wheel steering device displacement detection value in each cycle from a rear-wheel steering device displacement sensor associated with a rear-wheel steering device (16) of the vehicle; and is also provided with
The second determination module (22) is configured to:
the front wheel rotation angle value in the current period is determined based on the steering wheel rotation angle detection value in the current period, the rear wheel rotation angle value in the current period is determined based on the rear wheel rotation device displacement detection value in the current period, and the wheel speed conversion value of the corresponding wheel in the current period is determined based on the front wheel rotation angle value in the current period, the rear wheel rotation angle value in the current period, and the wheel speed detection value of the corresponding wheel in the current period.
4. A unit (12) according to claim 3, wherein the acquisition module (18) is configured to:
acquiring acceleration detection values of corresponding wheels in each cycle from the wheel speed sensor; and
acquiring a yaw rate detection value in each cycle from a yaw rate sensor associated with a chassis (17) of the vehicle, and
The correction module (24) is configured to:
determining an acceleration conversion value of the corresponding wheel in the current period based on the acceleration detection value and the yaw rate detection value of the corresponding wheel in the current period to represent a centroid acceleration magnitude generated when the acceleration of the corresponding wheel is converted to the vehicle centroid; and
the wheel speed conversion value of the corresponding wheel in the current period is corrected based on the acceleration conversion value of the corresponding wheel in the current period by using a Kalman filtering algorithm.
5. The unit (12) of claim 4, wherein the correction module (24) is configured to:
determining a wheel speed predicted value of the corresponding wheel in the current period based on the acceleration conversion value of the corresponding wheel in the current period by using a prediction model of a Kalman filtering algorithm, and
a wheel speed correction value of the corresponding wheel in the current period is determined based on the wheel speed conversion value and the wheel speed prediction value of the corresponding wheel in the current period by using an update model of a Kalman filtering algorithm, wherein when the wheel speed detection value of the corresponding wheel in the current period cannot be acquired from the wheel speed sensor by an acquisition module (18), the wheel speed prediction value of the corresponding wheel in the current period is taken as the wheel speed correction value.
6. The unit (12) according to any one of claims 1 to 5, wherein the third determination module (26) is configured to:
calculating a first average value of wheel speed correction values of the plurality of wheels in a current period; and
the vehicle speed value that changes by the first average value or by the reference vehicle speed magnitude in the last period with respect to the acceptable maximum vehicle speed change rate is determined as the reference vehicle speed magnitude in the current period based on the vehicle speed change rate of the first average value with respect to the reference vehicle speed magnitude in the last period.
7. The use unit (12) according to any one of claims 1 to 5, wherein the third determination module (26) is configured to:
calculating a first average value of wheel speed correction values of the plurality of wheels in a current period;
determining whether the wheel speed correction value of each wheel is available for determining a reference vehicle speed magnitude in the current period based on a correction value change rate of the wheel speed correction value of each wheel in the current period relative to the first average value;
calculating a second average of all wheel speed correction values usable to determine a reference vehicle speed magnitude in the current period; and
the vehicle speed value that changes by the second average value or by the reference vehicle speed magnitude in the previous cycle with respect to the acceptable maximum vehicle speed change rate is determined as the reference vehicle speed magnitude in the current cycle based on the vehicle speed change rate of the second average value with respect to the reference vehicle speed magnitude in the previous cycle.
8. The unit (12) according to claim 6 or 7, wherein the unit (12) further comprises a speed limiting module (30), the speed limiting module (30) being configured to:
when the calculated reference yaw rate based on the reference vehicle speed magnitude in the current period is larger than the yaw rate detection value in the current period multiplied by the safety coefficient, the vehicle speed value, in which the reference vehicle speed magnitude in the last period is changed with respect to the acceptable maximum vehicle speed change rate, is taken as the reference vehicle speed magnitude in the current period.
9. The unit (12) for determining a reference vehicle speed of a vehicle according to any one of claims 1 to 8, wherein the fourth determination module (28) is configured to determine the reference vehicle speed direction in the current period by at least one of:
when the wheel direction detection values of three or more than three wheels in the current period are positive, judging that the reference vehicle speed direction in the current period is positive;
when the wheel direction detection values of three or more than three wheels in the current period are inverse, judging that the reference vehicle speed direction in the current period is inverse;
when the wheel direction detection value of two wheels in the current period is positive and the wheel direction detection value of the other two wheels in the current period is negative, using the reference vehicle speed direction in the previous period as the reference vehicle speed direction in the current period; and
When the acquisition module (18) cannot acquire the wheel direction detection value of the corresponding wheel in the current period from the wheel speed sensor, the wheel direction detection value of the corresponding wheel in the previous period is taken as the wheel direction detection value of the corresponding wheel in the current period.
10. A method for determining a reference vehicle speed of a vehicle, the reference vehicle speed being adapted to calculating a desired rotation angle for a rear wheel of a plurality of wheels of the vehicle, the method being optionally performed with a unit (12) for determining a reference vehicle speed of a vehicle according to any one of claims 1 to 9, wherein the method comprises:
obtaining a wheel speed detection value and a wheel direction detection value of a corresponding wheel in each cycle from a wheel speed sensor associated with the corresponding wheel of the plurality of wheels;
determining whether the wheel speed detection value of the corresponding wheel in the current period is normal based on the detection value change rate of the wheel speed detection value of the corresponding wheel in the current period relative to the wheel speed detection value of the previous period, wherein when the wheel speed detection value of the corresponding wheel in the current period is abnormal, the wheel speed detection value of the corresponding wheel in the previous period is taken as the wheel speed detection value of the corresponding wheel in the current period;
Determining a wheel speed conversion value of the corresponding wheel in the current period based on the wheel speed detection value of the corresponding wheel in the current period to represent a centroid speed magnitude generated when the wheel speed of the corresponding wheel is converted to a vehicle centroid;
correcting the wheel speed conversion value of the corresponding wheel in the current period to generate a wheel speed correction value of the corresponding wheel in the current period;
determining a reference vehicle speed in the current period based on the wheel speed correction value of each wheel in the current period; and
the reference vehicle speed direction in the current period is determined based on the wheel direction detection value of each wheel in the current period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211094322.8A CN117719520A (en) | 2022-09-08 | 2022-09-08 | Unit and method for determining a reference vehicle speed of a vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211094322.8A CN117719520A (en) | 2022-09-08 | 2022-09-08 | Unit and method for determining a reference vehicle speed of a vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117719520A true CN117719520A (en) | 2024-03-19 |
Family
ID=90200278
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211094322.8A Pending CN117719520A (en) | 2022-09-08 | 2022-09-08 | Unit and method for determining a reference vehicle speed of a vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117719520A (en) |
-
2022
- 2022-09-08 CN CN202211094322.8A patent/CN117719520A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3805057A1 (en) | Method for controlling stability of vehicle, and device | |
| US8515619B2 (en) | Motion control unit for vehicle based on jerk information | |
| JP4019813B2 (en) | Physical quantity estimation device, road friction state estimation device, steering angle neutral point estimation device, and air pressure drop estimation device | |
| CN101657345B (en) | Device and method for estimating frictional condition of ground contact surface of wheel | |
| JPH1035443A (en) | Apparatus for presuming car body speed and coefficient of friction on road surface | |
| CN112455538B (en) | Vehicle rear wheel control method, device, vehicle and storage medium | |
| CN109866709B (en) | Vehicle driving wheel control system and vehicle driving wheel control method using the same | |
| Rubin et al. | Vehicle yaw stability control using rear active differential via sliding mode control methods | |
| US11485372B2 (en) | Standalone-type rear wheel steering control apparatus and method thereof | |
| JP6428497B2 (en) | Vehicle control device | |
| JP3271956B2 (en) | Road surface friction coefficient estimation device for vehicles | |
| CN117719520A (en) | Unit and method for determining a reference vehicle speed of a vehicle | |
| JP5251176B2 (en) | Vehicle running state estimation device | |
| JP3271964B1 (en) | Road surface friction coefficient estimation device for vehicles | |
| JP2013517988A (en) | Vehicle path tracking system and method | |
| CN116279523B (en) | Four-wheel steering driving electric automobile state estimation method | |
| JP2010155473A (en) | Turning behavior detection device, turning behavior detecting method, and yaw rate estimating method | |
| JP4862348B2 (en) | In-wheel motor control device | |
| JP2009149201A (en) | Vehicle control device | |
| CN115848384A (en) | Distributed-drive longitudinal speed determination method, device, equipment and medium | |
| Tan et al. | Vehicle Parameters Estimation Under Braking and Steering Condition Based on EKF Observer | |
| CN115675635A (en) | Control method and system for front wheel and rear wheel, electronic device, storage medium and vehicle | |
| KR20230091217A (en) | Tire friction limit estimator and method for controll torque-vectoring using the same | |
| CN116161102A (en) | Drive-by-wire steering control method and device and electronic equipment | |
| CN116279508A (en) | Road surface adhesion coefficient estimation method and medium based on rapid convergence SCKF and self-adaptive tire rigidity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |