Multi-axle vehicle speed fusion calculation method and related device

Abstract

The invention discloses a multi-axis vehicle speed fusion calculation method and a related device, and relates to the field of vehicle parameter estimation, and the method comprises the steps: obtaining a motor conversion vehicle speed and a driving wheel equivalent vehicle speed, and obtaining a corrected longitudinal acceleration integral vehicle speed, an updated rotating speed weight of a plurality of driven wheels, and a corrected longitudinal acceleration integral vehicle speed weight; based on the updated rotating speed weights of the multiple driven wheels, the rotating speeds of the multiple driven wheels in the current period, the corrected longitudinal acceleration integral vehicle speed weight and the corrected longitudinal acceleration integral vehicle speed, an equivalent vehicle speed is obtained through calculation; based on a preset vehicle speed weight, a preset motor conversion vehicle speed weight, the equivalent vehicle speed and the motor conversion vehicle speed, a fusion transition stage vehicle speed is obtained through calculation; obtaining a target vehicle speed calculation mode; and searching a target vehicle speed corresponding to the target vehicle speed calculation mode from a preset corresponding relation between the vehicle speed calculation mode and the vehicle speed. The method can be suitable for various low-adhesion road conditions, and can accurately calculate the target vehicle speed according to the information of each sensor in different fault states of the vehicle.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle parameter estimation, and in particular to a vehicle speed fusion calculation method and related devices for multi-axle vehicles. Background Art

[0002] In a multi-axle vehicle with wheel speed sensors, the speed calculation method is dynamically adjusted according to the vehicle's driving conditions and the reliability of the sensor to improve the accuracy and stability of the speed estimation. For example, when the vehicle is driving, the average speed method is usually used to calculate the speed. When the vehicle is braking, the maximum speed method is used to calculate the speed. In low adhesion conditions or when the wheel speed sensor is abnormal, the longitudinal acceleration integral of the acceleration sensor is used to calculate the speed.

[0003] The above-mentioned maximum speed method may result in abnormal vehicle speed when some wheel speed sensors output abnormally large values. The above-mentioned average speed method may result in abnormal vehicle speed when some wheel speed sensors have abnormally small values ​​or hardware disconnection. The above-mentioned longitudinal acceleration integration method may result in abnormal vehicle speed due to the deviation of the integral value for a long time due to the wheel speed sensor noise and insufficient or excessive correction of the zero bias effect, which may lead to abnormal vehicle speed.

[0004] In summary, the accuracy of the above method for calculating vehicle speed is low. Summary of the invention

[0005] In view of the above problems, the present application provides a method and a related device for calculating the vehicle speed fusion of a multi-axle vehicle, so as to achieve the purpose of obtaining the vehicle speed with high accuracy. The specific scheme is as follows:

[0006] In a first aspect, the present application provides a method for calculating vehicle speed fusion of a multi-axle vehicle, comprising:

[0007] Based on the fault flags of multiple motors, the equivalent speeds of the motors, and the slip states of the multiple motors, the motor-converted vehicle speeds are obtained;

[0008] Based on the fault flags respectively corresponding to the plurality of driving wheels and the rotation speeds respectively corresponding to the plurality of driving wheels, an equivalent vehicle speed of the driving wheels is calculated;

[0009] Obtaining a corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels;

[0010] Determining initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the respective cycles respectively corresponding to the plurality of driven wheels;

[0011] For any of the driven wheels, if the driven wheel is in a locked state and the initial speed weight of the driven wheel is not 0, determining the locking level of the driven wheel based on the speed of each cycle of the driven wheel;

[0012] If the locking level of at least one of the driven wheels is not 0, based on the longitudinal projections of the mounting points of the plurality of driven wheels in the vehicle body coordinate system and the initial speed weights of the plurality of driven wheels, the updated speed weights corresponding to the plurality of driven wheels are calculated;

[0013] Obtaining a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights respectively corresponding to the plurality of driven wheels;

[0014] Calculating an equivalent vehicle speed based on updated speed weights of the plurality of driven wheels, speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed;

[0015] Calculating the vehicle speed in the fusion transition phase based on a preset vehicle speed weight, a preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed;

[0016] Get the target vehicle speed calculation mode;

[0017] From the correspondence between the preset vehicle speed calculation mode and the vehicle speed, the target vehicle speed corresponding to the target vehicle speed calculation mode is searched, and the vehicle speed is any one of the corrected longitudinal acceleration integral vehicle speed, the equivalent vehicle speed, the motor converted vehicle speed, the fusion transition stage vehicle speed and the driving wheel equivalent vehicle speed.

[0018] In a possible implementation, the obtaining of the vehicle speed calculation mode includes:

[0019] If the fault flags of the plurality of motors, the fault flags corresponding to the plurality of driving wheels, and the fault flags corresponding to the plurality of driven wheels are all FALSE, or if the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to the preset rotation angle threshold and the number of fault flags of the plurality of driven wheels that are TRUE is within a preset range, the vehicle speed calculation mode is determined based on the equivalent vehicle speed;

[0020] If the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to the preset rotation angle threshold value and the number of the fault flags of the plurality of driven wheels being TRUE is greater than the preset range and the fault flags of the plurality of motors are all FALSE, determining that the vehicle speed calculation mode is the second mode;

[0021] If the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is greater than the preset rotation angle threshold and the fault flags of the left driven wheel of the first bridge and the left driven wheel of the fourth bridge among the fault flags of the plurality of motors are both TRUE or the fault flags of the right driven wheel of the first bridge and the right driven wheel of the fourth bridge are both TRUE, and the fault flags of the plurality of motors are not all TRUE, determining that the vehicle speed calculation mode is the second mode;

[0022] If the fault flags of the plurality of motors, the fault flags of the plurality of driving wheels, and the fault flags of the plurality of driven wheels are all TRUE, determining that the vehicle speed calculation mode is the zeroth mode;

[0023] If the fault flags of the plurality of driven wheels are all TRUE, the fault flags of the plurality of motors are all TRUE, and the fault flags of the plurality of driving wheels are all FALSE, it is determined that the vehicle speed calculation mode is the fourth mode.

[0024] In a possible implementation, determining the vehicle speed calculation mode based on the equivalent vehicle speed includes:

[0025] If the equivalent vehicle speed is less than the preset lower boundary of the fusion interval speed, and the slip state of the plurality of motors is no slip, determining that the vehicle speed calculation mode is the second mode;

[0026] If the equivalent vehicle speed is greater than or equal to the preset lower boundary of the fusion interval speed and less than or equal to the preset upper boundary of the fusion interval speed, and the slip state of the plurality of motors is no slip, determining that the vehicle speed calculation mode is the third mode;

[0027] If the equivalent vehicle speed is greater than the preset upper boundary of the fusion interval speed, the vehicle speed calculation mode is determined to be the first mode.

[0028] In a possible implementation, the multiple motors include a first motor and a second motor, and obtaining the motor-converted vehicle speed based on the fault flags of the multiple motors, the motor equivalent speeds, and the slip states of the multiple motors includes:

[0029] If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is greater than or equal to a first preset torque threshold, or the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have different rotation directions, it is determined that the minimum speed of the first motor and the second motor is the equivalent speed;

[0030] If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is less than the first preset torque threshold, determine that the maximum speed of the first motor and the second motor is the equivalent speed;

[0031] Based on the equivalent speed, determining motor speed weights corresponding to the first motor and the second motor respectively;

[0032] If the fault flags of the plurality of motors are all FALSE, obtaining a first speed gradient of the first motor at a plurality of periodic intervals and a second speed gradient of the second motor at a plurality of periodic intervals;

[0033] Determine the maximum value of the first speed gradient and the second speed gradient as the maximum driving speed gradient;

[0034] If the maximum driving speed gradient is greater than or equal to a first preset gradient threshold, determining that the motor speed weights corresponding to the first motor and the second motor are zero;

[0035] If the maximum driving speed gradient is less than the first preset gradient threshold, determining the absolute value of the difference between the speed of the first motor and the speed of the second motor as the front and rear motor speed separation;

[0036] If the speed separation of the front and rear motors is less than the preset speed separation threshold, and the maximum driving speed gradient is less than the first preset gradient threshold, determining that the motor speed weights corresponding to the first motor and the second motor are 1 respectively;

[0037] If the speed separation of the front and rear motors is greater than or equal to a preset speed separation threshold, determining that the motor speed weights corresponding to the first motor and the second motor are zero;

[0038] If the motor speed weights of the first motor are both zero and the motor speed weights of the second motor are both zero, determining that the motor-converted vehicle speed is 0;

[0039] If at least one of the motor speed weight of the first motor and the motor speed weight of the second motor is not zero, the motor-converted vehicle speed is calculated based on the tire rolling radius, the motor-to-wheel end transmission ratio, the driven front axle left wheel angle, the driven front axle right wheel angle, the driven rear axle left wheel angle and the driven rear axle right wheel angle, the motor speed weight of the first motor and the motor speed weight of the second motor.

[0040] In a possible implementation, the plurality of driving wheels include a front axle left driving wheel, a front axle right driving wheel, a rear axle left driving wheel, and a rear axle right driving wheel;

[0041] The calculating the equivalent vehicle speed of the driving wheels based on the fault flags respectively corresponding to the plurality of driving wheels and the rotation speeds respectively corresponding to the plurality of driving wheels comprises:

[0042] For each of the driving wheels, if the fault flag of the driving wheel is TRUE, determining that the driving wheel speed weight of the driving wheel is zero;

[0043] For each of the driving wheels, if the fault flag of the driving wheel is FALSE, determine the absolute value of the difference between the rotation speed of the left driving wheel of the front axle and the rotation speed of the right driving wheel of the front axle, which is the front axle driving wheel rotation speed difference;

[0044] Determine the absolute value of the difference between the rotation speed of the left driving wheel of the rear axle and the rotation speed of the right driving wheel of the rear axle, which is the rear axle driving wheel rotation speed difference;

[0045] If the speed difference of the front axle driving wheels is greater than a preset speed threshold, determining that the driving wheel speed weights corresponding to the left front axle driving wheel and the right front axle driving wheel are zero;

[0046] If the front axle drive wheel speed difference is less than or equal to the preset speed threshold, determining that the drive wheel speed weights corresponding to the front axle left drive wheel and the front axle right drive wheel are 1;

[0047] If the rear axle drive wheel speed difference is greater than the preset speed threshold, determining that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are zero;

[0048] If the rear axle drive wheel speed difference is less than or equal to the preset speed threshold, determining that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are 1;

[0049] Based on the rotation speed of the left driving wheel of the front axle, the driving wheel rotation speed weight of the left driving wheel of the front axle, the rotation speed of the right driving wheel of the front axle and the driving wheel rotation speed weight of the right driving wheel of the front axle, the average longitudinal rotation speed of the front axle is calculated;

[0050] Based on the driving wheel speed weight of the left driving wheel of the rear axle, the driving wheel speed weight of the right driving wheel of the rear axle, the speed of the left driving wheel of the rear axle, and the speed of the right driving wheel of the rear axle, the average longitudinal speed of the rear axle is calculated;

[0051] The driving wheel equivalent vehicle speed is calculated based on the average longitudinal rotation speed of the front axle and the average longitudinal rotation speed of the rear axle.

[0052] In a possible implementation, the plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges;

[0053] The step of obtaining the corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels comprises:

[0054] Get real-time longitudinal acceleration;

[0055] For each cycle, if the vehicle is in a braking state, and the real-time longitudinal acceleration of the vehicle is greater than |a first preset acceleration threshold value| when the gear position of the vehicle is D gear, or the real-time longitudinal acceleration of the vehicle is less than -|a first preset acceleration threshold value| when the gear position of the vehicle is R gear, and the real-time longitudinal acceleration is less than the second preset acceleration threshold value, the initial longitudinal acceleration of the cycle is set to 0;

[0056] Determine the maximum value among the equivalent vehicle speed of each cycle of the left driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the left driven wheel of the fourth bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the fourth bridge, and the vehicle speed before each cycle as the acceleration integration starting point;

[0057] The corrected longitudinal acceleration integrated vehicle speed is calculated based on the acceleration integration starting point and the initial longitudinal acceleration of each cycle.

[0058] In a possible implementation, the method further includes:

[0059] Based on the corrected longitudinal acceleration integrated vehicle speed, the preset vehicle speed L1 level upper limit gain, the preset vehicle speed L1 level lower limit gain, and the preset L1 level speed upper and lower limit envelope widths, the vehicle speed L1 level upper limit and the vehicle speed L1 level lower limit are calculated;

[0060] Based on the corrected longitudinal acceleration integrated vehicle speed V ACC , the preset L2 level speed upper limit gain, the preset L2 level speed lower limit gain, the preset L2 level speed upper and lower limit envelope widths, and the L2 level speed upper and lower limit are calculated to obtain the L2 level speed upper and lower limit.

[0061] In a possible implementation, the plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges;

[0062] The determining of initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of each cycle respectively corresponding to the plurality of driven wheels comprises:

[0063] For each of the driven wheels, if the fault flag of the driven wheel is TRUE, determining the initial speed weight of the driven wheel to be 0;

[0064] For each of the driven wheels, if the fault flag of the driven wheel is FALSE, and the difference between the speed of the current cycle of the driven wheel and the speed of the previous cycle is greater than or equal to the preset speed threshold, the initial speed weight of the driven wheel is determined to be 0, otherwise the initial speed weight is determined to be 1.

[0065] In a possible implementation, if the driven wheel is in a locked state and the initial speed weight of the driven wheel is not 0, determining the locking level of the driven wheel based on the speed of each cycle of the driven wheel includes:

[0066] If the vehicle is in a braking state, and the maximum absolute value of the driven wheel turning angle of the plurality of driven wheels is less than the preset turning angle threshold, and the real-time speed V of the vehicle is x The speed is greater than a preset detection speed threshold, and the gear position of the vehicle is D gear or R gear, enabling locking detection;

[0067] For each of the driven wheels, if the fault flag of the driven wheel is FALSE, obtaining the speed drop gradient of the driven wheel at each period interval;

[0068] If the minimum value of the speed drop gradient of the plurality of driven wheels in each period interval is greater than the preset speed drop gradient threshold, the initial locking level of the plurality of driven wheels is determined to be zero; otherwise, the initial locking level of the plurality of driven wheels is determined to be 1;

[0069] For each of the driven wheels, if the rotation speed of the driven wheel is greater than the lower limit of the vehicle speed L1 level and the initial locking level of the driven wheel is zero, determining that the locking level of the driven wheel is zero;

[0070] For each of the driven wheels, if the rotation speed of the driven wheel is greater than or equal to the vehicle speed L2 level lower limit and less than or equal to the vehicle speed L1 level lower limit, determining the locking level of the driven wheel to be 1;

[0071] For each of the driven wheels, if the rotation speed of the driven wheel is less than the lower limit of the vehicle speed L1 level, the locking level of the driven wheel is determined to be 2.

[0072] A second aspect of the present application provides a vehicle speed fusion calculation device for a multi-axle vehicle, comprising:

[0073] A first acquisition module is used to acquire the motor-converted vehicle speed based on the fault flags of the multiple motors, the motor equivalent speeds, and the slip states of the multiple motors;

[0074] A first calculation module, configured to calculate an equivalent vehicle speed of a driving wheel based on fault flags corresponding to a plurality of driving wheels and rotation speeds corresponding to the plurality of driving wheels;

[0075] A second acquisition module is used to obtain a corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels;

[0076] A first determination module, configured to determine initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the respective cycles respectively corresponding to the plurality of driven wheels;

[0077] a second determination module, configured to determine, for any of the driven wheels, a locking level of the driven wheel based on the rotation speed of each cycle of the driven wheel if the driven wheel is in a locked state and the initial rotation speed weight of the driven wheel is not 0;

[0078] A second calculation module is configured to calculate, if the locking level of at least one of the driven wheels is not 0, updated speed weights corresponding to the plurality of driven wheels respectively based on the longitudinal projections of the mounting points of the plurality of driven wheels in the vehicle body coordinate system and the initial speed weights of the plurality of driven wheels;

[0079] A third acquisition module is used to acquire a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights respectively corresponding to the plurality of driven wheels;

[0080] a third calculation module, configured to calculate an equivalent vehicle speed based on the updated speed weights of the plurality of driven wheels, the speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed;

[0081] A fourth calculation module, configured to calculate the vehicle speed in the fusion transition phase based on a preset vehicle speed weight, a preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed;

[0082] A fourth acquisition module, used for acquiring a target vehicle speed calculation mode;

[0083] A search module is used to search for a target vehicle speed corresponding to the target vehicle speed calculation mode from a correspondence between a preset vehicle speed calculation mode and a vehicle speed, wherein the vehicle speed is any one of the corrected longitudinal acceleration integrated vehicle speed, the equivalent vehicle speed, the motor-converted vehicle speed, the fusion transition phase vehicle speed and the drive wheel equivalent vehicle speed.

[0084] A third aspect of the present application provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the method for multi-axle vehicle speed fusion calculation according to the first aspect or any implementation of the first aspect.

[0085] A fourth aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:

[0086] The memory is used to store computer programs;

[0087] The processor is used to execute the computer program so that the electronic device can implement the vehicle speed fusion calculation method for a multi-axle vehicle according to the first aspect or any implementation of the first aspect.

[0088] A fifth aspect of the present application provides a computer storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the method for multi-axle vehicle speed fusion calculation according to the above-mentioned first aspect or any implementation of the first aspect.

[0089] By means of the above technical scheme, the present application provides a method for calculating the vehicle speed fusion of a multi-axis vehicle, obtaining the motor conversion vehicle speed, the equivalent vehicle speed of the driving wheel, the corrected longitudinal acceleration integral vehicle speed, the updated speed weights of multiple driven wheels, and the corrected longitudinal acceleration integral vehicle speed weights; based on the updated speed weights of multiple driven wheels, the current cycle speeds of multiple driven wheels, the corrected longitudinal acceleration integral vehicle speed weights, and the corrected longitudinal acceleration integral vehicle speeds, the equivalent vehicle speed is calculated; based on the preset vehicle speed weights, the preset motor conversion vehicle speed weights, the equivalent vehicle speed, and the motor conversion vehicle speed, the vehicle speed in the fusion transition phase is calculated; the target vehicle speed calculation mode is obtained; from the corresponding relationship between the preset vehicle speed calculation mode and the vehicle speed, the target vehicle speed corresponding to the target vehicle speed calculation mode is searched. The embodiment of the present application can be applied to various low-adhesion road conditions, and under different vehicle fault conditions, the target vehicle speed can be accurately calculated according to the information of each sensor, so as to provide stable and accurate input parameters for vehicle control to the maximum extent. At the same time, the method proposed in this application can ensure that the calculation results are stable and there is no speed jump phenomenon, and the calculation time meets the performance requirements of general vehicle controllers. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0091] Figure 1 A schematic diagram of the architecture of a multi-axle vehicle provided in this application;

[0092] Figure 2 A schematic diagram of input and output of a multi-axle vehicle speed fusion calculation method provided in this application;

[0093] Figure 3 A schematic diagram of a flow chart of a method for calculating vehicle speed fusion of a multi-axle vehicle provided in an embodiment of the present application;

[0094] Figure 4 A schematic diagram of the structure of a vehicle speed fusion calculation device for a multi-axle vehicle provided in an embodiment of the present application;

[0095] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0096] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0097] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0098] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0099] In the related art, the speed of a vehicle can be calculated by the following method.

[0100] The maximum speed method is a method for estimating the reference speed of a vehicle. Its basic principle is to collect the speed signals of multiple wheels of the vehicle in real time and select the maximum value as the reference speed of the vehicle.

[0101] The average speed method is a method of estimating the vehicle's reference speed by calculating the average speed of multiple wheels of the vehicle.

[0102] Acceleration integration method is a method to calculate velocity and displacement by integrating acceleration signals.

[0103] In order to accurately estimate the vehicle speed and provide stable and reliable parameter information for the vehicle chassis control as much as possible, it is necessary to dynamically adjust the weights of different sensor data sources under different working conditions and different road conditions. In related technologies, multi-axle vehicles only distribute signal source weights in a fixed ratio. If some wheel speed sensors output abnormally large values, the maximum speed method will obtain an abnormal speed that is much greater than the actual speed; if some wheel speed sensors have abnormally small values ​​or hardware disconnection, the average speed method will output an abnormal speed that is much less than the actual speed; if the acceleration integration method is used directly, the sensor noise and the lack or excessive correction of the zero bias effect will lead to deviation of the integral value for a long time.

[0104] The wheel angle and yaw rate are not considered in the related art. When the vehicle turns and drives diagonally, the changes in the wheel angle and yaw rate will have a significant impact on the longitudinal speed of the vehicle. However, the methods in the related art usually only focus on the data of the wheel speed sensor and the acceleration sensor, and ignore these important dynamic information, which results in the inability to provide accurate longitudinal speed of the vehicle when the vehicle turns and drives diagonally. On the one hand, it is because the methods in the related art ignore the above dynamic information; on the other hand, the methods in the related art of extreme working conditions do not use sensor information comprehensively, resulting in a certain type of sensor having too much weight in the vehicle speed calculation, resulting in inaccurate speed estimation. Therefore, the vehicle speed estimation algorithm in the related art cannot accurately estimate the vehicle longitudinal speed (referring to the speed of the vehicle in the forward direction in the vehicle body coordinate system) when some wheel speed sensors fail, the driving wheel slips on low-adhesion roads, the driving wheel or driven wheel locks on low-adhesion roads, and the wheel speed sensor has a dead zone. It cannot provide accurate longitudinal speed of the vehicle, that is, the target speed, when the vehicle turns and drives diagonally.

[0105] Based on this, this application aims at the practical problems that the related technologies cannot be applied to low-adhesion road conditions, partial sensor failures, wheel speed sensor dead zones, etc., and proposes a vehicle speed fusion calculation method for multi-axle vehicles. By identifying the current sensor state, vehicle speed, vehicle drive slippage, and vehicle brake lock state, the vehicle speed calculation mode switching or fusion calculation is realized. This application can guarantee the accuracy of target vehicle speed calculation to the greatest extent under conditions such as failure of some wheel speed sensors of the vehicle, slippage on low-adhesion road surfaces, and speed jump caused by vehicle ABS triggering.

[0106] See also Figure 1 , Figure 1 The schematic diagram of the structure of a multi-axle vehicle is shown. The multi-axle vehicle may include: a wheel speed sensor 100, a motor controller 200, a rotation angle sensor 300, an acceleration sensor 400, a vehicle controller 500, a motor 600, a steering mechanism 700, and a braking system 800.

[0107] Wheel speed sensors 100 are important sensors for measuring wheel speed in multi-axle vehicles. They are usually installed on each wheel to monitor the rotation speed of the wheel in real time. The output signal of the wheel speed sensor is usually a pulse signal, and the wheel speed is determined by counting the number of pulses per unit time.

[0108] The wheel speed sensor 100 can provide real-time rotation speed information of the wheel for vehicle speed calculation, anti-lock braking system (ABS), traction control system (TCS), etc.

[0109] The pulse signal output by the wheel speed sensor 100 may be processed by an electronic control unit (ECU) of the vehicle.

[0110] Exemplarily, the wheels in a multi-axle vehicle may include one or more driven wheels (non-driven wheels) and one or more driving wheels (active wheels). Active wheels are wheels that are directly driven by the vehicle's power system, usually connected to an engine or motor to provide the vehicle's driving force. Driven wheels are not directly connected to the power system, and their main function is to support the vehicle's weight and provide steering and braking forces. Therefore, the wheel speed sensor can output the speed of the driven wheels and the speed of the active wheels.

[0111] For example, one or more driving wheels include: a left front driving wheel Drvfl, a right front driving wheel Drvfr, a left rear driving wheel Drvrl, and a right rear driving wheel Drvrr; one or more driven wheels include: a left front driven wheel whlfl, a right front driving wheel whlfr, a left rear driving wheel whlrl, and a right rear driving wheel whlrr; then the wheel speed sensor can output the rotation speed n of the left front driving wheel Drvfl Drvfl , the speed of the right front drive wheel Drvfr n Drvfr , the speed of the left rear drive wheel Drvrl n Drvrl and the speed n of the right rear drive wheel Drvrr Drvrr , the speed of the front driven wheel whlfl n whlfl , the speed of the right front drive wheel whlfr n whlfr , the speed of the left rear drive wheel whlrl n whlrl and the speed n of the right rear drive wheel whlrr whlrr .

[0112] The motor controller 200 is one of the core components of a multi-axle vehicle and is used to control the operating state of the motor, including parameters such as the motor speed and torque. The motor controller receives instructions from the vehicle controller and adjusts the output power of the motor, thereby achieving vehicle driving and braking.

[0113] Exemplarily, the motor controller 200 may output the following signals: motor speed, motor torque, fault flag, etc.

[0114] Exemplarily, the motor 600 can provide driving force for the vehicle and is usually installed on a drive shaft of the vehicle.

[0115] It is understandable that the multi-axle vehicle may include one or more motors 600. Exemplarily, the motors in the multi-axle vehicle may include a front drive motor f and a rear drive motor r. Exemplarily, the front drive motor is usually installed at the front of the vehicle and connected to the front wheel drive shaft. It is used to provide driving force for the front wheels to achieve the front wheel drive (FF) or all-wheel drive (AWD) of the vehicle. The rear drive motor is installed at the rear of the vehicle and is usually connected to the rear wheel drive shaft; it is used to provide driving force for the rear wheels to achieve the rear wheel drive (FR) or all-wheel drive (AWD) of the vehicle. In summary, the motor controller 200 can output the speed of the front drive motor, the speed of the rear drive motor, the front drive motor torque, the rear drive motor torque, the front drive motor fault flag, and the rear drive motor fault flag.

[0116] The motor controller 200 can output the driving motor speed n of the front driving motor f f , Fault flag of front drive motor E f , the rear drive motor r's drive motor speed n r , rear drive motor r fault flag E r .

[0117] The rotation angle sensor 300 is used to measure the rotation angle of the wheel relative to the longitudinal axis of the vehicle. It is usually installed in the steering mechanism 700 to monitor the steering angle of the wheel in real time. It can be understood that the wheel includes one or more driven wheels and one or more driving wheels, so the rotation angle sensor 300 can output the driven wheel angle of the driven wheel and the driving wheel angle of the driving wheel.

[0118] For example, one or more driving wheels include: a left front driving wheel Drvfl, a right front driving wheel Drvfr, a left rear driving wheel Drvrl, and a right rear driving wheel Drvrr; one or more driven wheels include: a left front driven wheel whlfl, a right front driving wheel whlfr, a left rear driving wheel whlrl, and a right rear driving wheel whlrr; the turning angle sensor can output the turning angle α of the left front driving wheel Drvfl 2l 、The turning angle α of the right front driving wheel Drvfr 2r 、The turning angle α of the left rear driving wheel Drvrl 3l and the turning angle α of the right rear drive wheel Drvrr 3r 、The rotation angle α of the front driven wheel whlfl fl 、The turning angle α of the right front driving wheel whlfr fr 、The turning angle α of the left rear driving wheel whlrl rl and the turning angle α of the right rear drive wheel whlrr rr .

[0119] Exemplarily, the turning angle sensor 300 is combined with a yaw rate sensor of the vehicle to calculate the turning radius and yaw rate of the vehicle.

[0120] The acceleration sensor 400 is used to measure the longitudinal acceleration A of the vehicle. X And lateral acceleration. It is usually installed on the chassis of the vehicle to monitor the acceleration status of the vehicle in real time.

[0121] The acceleration sensor 400 can provide longitudinal acceleration information of the vehicle for vehicle speed calculation and dynamic control.

[0122] The acceleration sensor 400 can provide lateral acceleration information of the vehicle for vehicle stability control.

[0123] Exemplarily, the multi-axle vehicle further includes a torque sensor, a brake sensor, and a yaw rate sensor.

[0124] For example, the installation location of the torque sensor depends on the vehicle's power system architecture and control requirements. The torque sensor is installed on the output shaft of the motor, usually between the motor and the reducer. The motor torque of the motor can be obtained through the torque sensor, such as the drive motor torque T of the front drive motor. f , the rear drive motor torque T r .

[0125] For example, the yaw rate sensor can obtain the yaw rate The yaw rate is one of the key parameters for vehicle dynamic control, which reflects the rotational motion of the vehicle on the horizontal plane. The yaw rate sensor is usually installed near the center of mass of the vehicle, usually in the middle of the vehicle chassis. Installing it near the center of mass ensures that the yaw rate measured by the sensor best reflects the overall rotational motion of the vehicle, reducing measurement errors caused by uneven vehicle structure and load distribution.

[0126] The vehicle controller 500 is the central control unit of a multi-axle vehicle, responsible for coordinating and managing the various subsystems of the vehicle. It receives signals from sensors, calculates the operating status of the vehicle, and issues control instructions to the motor controller, brake system, etc.

[0127] Exemplarily, the vehicle controller 500 may receive signals from wheel speed sensors, rotation angle sensors, acceleration sensors, etc. The vehicle controller 500 may calculate the real-time speed and dynamic state of the vehicle, issue control instructions to the motor controller, brake system, etc., monitor the fault state of the vehicle, and perform fault diagnosis.

[0128] For example, the vehicle controller 500 can determine whether a driven wheel and a driving wheel have a fault based on signals from a wheel speed sensor, a steering angle sensor, a torque sensor, and a brake sensor, and generate a fault flag.

[0129] For example, one or more driving wheels include: a left front driving wheel Drvfl, a right front driving wheel Drvfr, a left rear driving wheel Drvrl, and a right rear driving wheel Drvrr; one or more driven wheels include: a left front driven wheel whlfl, a right front driving wheel whlfr, a left rear driving wheel whlrl, and a right rear driving wheel whlrr; then the vehicle controller 500 can output the fault flag E of the left front driving wheel Drvfl. Drvfl , Fault flag position E of right front drive wheel Drvfr Drvfr , Fault flag position E of left rear drive wheel Drvrl Drvrl and the fault flag position E of the right rear drive wheel Drvrr Drvrr , Fault flag position E of the front driven wheel whlfl whlfl , Fault flag position E of right front drive wheel whlfr whlfr , Fault flag position E of left rear drive wheel whlrl whlrl And the fault flag position E of the right rear drive wheel whlrr whlrr .

[0130] For example, the vehicle controller 500 may obtain the vehicle gear position G st .

[0131] Exemplarily, the steering mechanism 700 includes a steering column, a steering knuckle, etc., for realizing the steering of the wheels. The steering angle sensor 300 is installed in the steering mechanism.

[0132] Illustratively, the braking system 800 includes, but is not limited to, brakes and ABS (Anti-lock Braking System).

[0133] The principle of the vehicle speed fusion calculation method for a multi-axle vehicle provided in an embodiment of the present application is explained below.

[0134] like Figure 2 As shown, it is a schematic diagram of the input and output of the vehicle speed fusion calculation method for a multi-axle vehicle provided in an embodiment of the present application.

[0135] like Figure 2 As shown, the driving wheel speed: the speed of the left front driving wheel Drvfl n Drvfl , the speed of the right front drive wheel Drvfr n Drvfr , the speed of the left rear drive wheel Drvrl n Drvrl , the speed of the right rear drive wheel Drvrr Drvrr; Driven wheel speed: the speed of the front driven wheel whlfl n whlfl , the speed of the right front drive wheel whlfr n whlfr , the speed of the left rear drive wheel whlrl n whlrl and the speed n of the right rear drive wheel whlrr whlrr , which can be obtained by the wheel speed sensor 100.

[0136] Driving wheel angle: the angle α of the left front driving wheel Drvfl 2l 、The turning angle α of the right front driving wheel Drvfr 2r 、The turning angle α of the left rear driving wheel Drvrl 3l and the turning angle α of the right rear drive wheel Drvrr 3r ; Driven wheel angle: the angle α of the front driven wheel whlfl fl 、The turning angle α of the right front driving wheel whlfr fr 、The turning angle α of the left rear driving wheel whlrl rl and the turning angle α of the right rear drive wheel whlrr rr , which can be obtained by the rotation angle sensor 300.

[0137] Drive motor speed n of front drive motor f , Fault flag of front drive motor E f , the rear drive motor r's drive motor speed n r , rear drive motor r fault flag E r , which can be obtained through the motor controller 200.

[0138] Longitudinal acceleration A X and yaw angular velocity φ can be obtained by the acceleration sensor.

[0139] The vehicle gear position G of the vehicle st It can be obtained through the vehicle controller.

[0140] Left front drive wheel Drvfl fault flag E Drvfl , Fault flag position E of right front drive wheel Drvfr Drvfr , Fault flag position E of left rear drive wheel Drvrl Drvrl , Fault flag position E of right rear drive wheel Drvrr Drvrr , Fault flag position E of the front driven wheel whlfl whlfl , Fault flag position E of right front drive wheel whlfr whlfr , Fault flag position E of left rear drive wheel whlrl whlrl And the fault flag position E of the right rear drive wheel whlrr whlrr , which can be obtained through the vehicle controller.

[0141] The output of the vehicle speed fusion calculation method for multi-axle vehicles provided in the embodiment of the present application is the target vehicle speed V x And the target vehicle speed calculation mode.

[0142] Combine the following Figure 1 and Figure 2 The vehicle speed fusion calculation method for a multi-axle vehicle provided in an embodiment of the present application is explained.

[0143] Reference Figure 3 , Figure 3 A flow chart of a method for calculating the vehicle speed fusion of a multi-axle vehicle provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, a method for calculating vehicle speed fusion of a multi-axle vehicle provided in an embodiment of the present application may include steps S301 to S311, and these steps are described in detail below.

[0144] Step S301: Based on the fault flags of multiple motors, the equivalent speeds of the motors, and the slip states of the multiple motors, obtain the motor-converted vehicle speed V mtrspd .

[0145] The units of vehicle speed and motor speed are different, so converting motor speed to vehicle speed means converting the vehicle speed using motor speed units.

[0146] Exemplarily, the value of the fault flag bit is TRUE or FALSE, wherein the value of the fault flag bit is FALSE, indicating that there is no fault, and the value of the fault flag bit is TRUE, indicating that there is a fault.

[0147] For example, the unit of rotation speed is rpm, the unit of speed is m / s, the unit of rotation angle is deg, the unit of torque is Nm, the unit of angular velocity is deg / s, and the unit of acceleration is m / s. 2 , state and mode are dimensionless enumerations.

[0148] Exemplarily, the present application may be executed once at every preset time interval. Exemplarily, the preset time interval may be determined based on actual conditions, such as 10 ms.

[0149] Exemplarily, the motor equivalent speed is determined based on fault flags of the multiple motors, torques of the multiple motors, and rotations of the multiple motors.

[0150] The reasons why the motor may slip include but are not limited to: low adhesion road surface, excessive vehicle acceleration, tire wear or insufficient tire pressure, and uneven vehicle load distribution.

[0151] Exemplarily, the slipping state may include: no slipping or slipping.

[0152] For example, if the motor has abnormal message loss, resolver failure, etc., the motor speed and torque signal will not be considered as valid information, the motor speed will not be included in the vehicle speed calculation, and the motor fault flag will be TRUE.

[0153] Exemplarily, the multiple motors include a front drive motor and a rear drive motor, and the motor speed weights of the multiple motors can be determined based on the fault flags of the multiple motors. Specifically, the weights can be determined by the following formula:

[0154] , where the motor speed weight of the front drive motor is W fmtr , the motor speed weight of the rear drive motor is W rmtr .

[0155] Step S302: Calculate the equivalent vehicle speed V of the driving wheels based on the fault flags corresponding to the multiple driving wheels and the speeds corresponding to the multiple driving wheels. Drvspd .

[0156] The driving wheel equivalent vehicle speed reflects the actual vehicle speed represented by the driving wheels under specific working conditions, and is usually used in areas such as vehicle power system control, fault diagnosis, and vehicle dynamic control.

[0157] Step S303: Based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to the plurality of driven wheels, and the vehicle speed of each cycle corresponding to the plurality of driven wheels, a corrected longitudinal acceleration integrated vehicle speed V is obtained. ACC .

[0158] The implementation process of step S303 is described below. The method includes the following steps A11 to A14.

[0159] The multiple driven wheels include one bridge left driven wheel, one bridge right driven wheel, four bridge left driven wheels, and four bridge right driven wheels.

[0160] Step A11: Obtain real-time longitudinal acceleration.

[0161] For example, the real-time longitudinal acceleration can be obtained, but the accuracy of the real-time longitudinal acceleration may be low, so correction is required.

[0162] Step A12: For each cycle, if the vehicle is in a braking state, and the real-time longitudinal acceleration is greater than |the first preset acceleration threshold value| when the gear position of the vehicle is D gear, or the real-time longitudinal acceleration is less than -|the first preset acceleration threshold value| when the gear position of the vehicle is R gear, and the real-time longitudinal acceleration is less than the second preset acceleration threshold value, the initial longitudinal acceleration of the cycle is set to 0.

[0163] Exemplarily, the first preset acceleration threshold can be expressed as ARevsThrs Exemplarily, the first preset acceleration threshold may be a positive threshold for detecting a reverse acceleration.

[0164] For example, the second preset acceleration threshold may be determined based on actual conditions, such as 0.15 m / s 2 .

[0165] For example, step A12 may be represented by the following information: when the vehicle is in a braking state and the vehicle gear is in gear D, the real-time longitudinal acceleration A x >A RevsThrs Or the real-time longitudinal acceleration A when the vehicle gear is in R gear x <-A RevsThrs , and V x <0.15m / s 2 , set the initial longitudinal acceleration A X is 0.

[0166] Step A12 is to avoid the influence of the sinusoidal noise generated by the vibration of the vehicle body on the integral of the accelerometer sensor value at the end of braking.

[0167] If the condition in step A12 is met, the initial longitudinal acceleration of the cycle is set to 0, otherwise, the acceleration correction function is not activated.

[0168] Step A13: Determine the maximum value of the equivalent vehicle speed of each cycle of the left driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the left driven wheel of the fourth bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the fourth bridge and the vehicle speed before each cycle as the starting point of acceleration integration.

[0169] For example, the acceleration integration starting point V spdst =max{Equivalent vehicle speed V of the left driven wheel of the first bridge in each cycle flprv , the equivalent vehicle speed V of the right driven wheel of the first bridge in each cycle frprv , the equivalent vehicle speed V of each cycle of the left driven wheel of the four-axle rlprv , the equivalent vehicle speed V of each cycle of the right driven wheel of the fourth bridge rrprv , the vehicle speed V before each cycle xprev}.

[0170] Step A14: Based on the acceleration integration starting point and the initial longitudinal acceleration of each cycle, the corrected longitudinal acceleration integrated vehicle speed V is calculated. ACC .

[0171] For example, the corrected longitudinal acceleration integrated vehicle speed V ACC =V spdst +Σ i=n-m n (AX (i)×△T), where △T is the duration of a cycle. n is the number of cycles of the current time; and m is the window length of the acceleration integration.

[0172] Exemplarily, the value of ΔT may be determined based on actual conditions, such as 0.01s, and the value of m may be determined based on actual conditions, such as m is 10.

[0173] In summary, longitudinal acceleration oscillation correction is achieved through the above steps A11 to A14.

[0174] Step S304: determining initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the respective cycles respectively corresponding to the plurality of driven wheels.

[0175] Exemplarily, the implementation method of step S304 includes the following steps C11 to C12.

[0176] The multiple driven wheels include one bridge left driven wheel, one bridge right driven wheel, four bridge left driven wheels, and four bridge right driven wheels.

[0177] Step C11: for each of the driven wheels, if the fault flag of the driven wheel is TRUE, determine that the initial speed weight of the driven wheel is 0.

[0178] Step C12: For each driven wheel, if the fault flag of the driven wheel is FALSE, and the difference between the speed of the current cycle of the driven wheel and the speed of the previous cycle is greater than or equal to the preset speed threshold n wdiffThrs , determine that the initial speed weight of the driven wheel is 0, otherwise determine that the initial speed weight is 1.

[0179] For example, the difference n diff =n f -n fprev Among them, n f is the speed of the driven wheel in the current cycle; n fprev is the speed of the driven wheel in the previous cycle of the current cycle.

[0180] It is understandable that if n diff > n wdiffThrs , then the wheel speed of the driven wheel is considered abnormal, and the initial speed weight of the corresponding driven wheel is 0; if n diff ≤ n wdiffThrs The wheel speed of the driven wheel is considered to be normal, and the corresponding initial speed weight of the driven wheel is 1.

[0181] In summary, the calculation of the effectiveness of the driven wheel speed is achieved through steps C11 to C12.

[0182] Step S305: for any of the driven wheels, if the driven wheel is in a locked state and the initial speed weight of the driven wheel is not 0, determine the locking level of the driven wheel based on the speed of each cycle of the driven wheel.

[0183] Exemplarily, the implementation of step S305 includes the following steps D11 to D16.

[0184] Step D11: If the vehicle is in a braking state, and the maximum absolute value of the driven wheel rotation angle of the plurality of driven wheels is less than the preset steering judgment angle threshold α TurnThrs , and the vehicle's real-time speed V x If the speed is greater than a preset detection speed threshold and the gear position of the vehicle is D gear or R gear, locking detection is enabled.

[0185] For example, if the vehicle is in gear D, then A X <0&&A X <A LCKThrs Among them, A LCKThrs is the locking judgment enabling deceleration speed threshold. For example, if the vehicle's gear is R gear, then A X >0&&A X >-A LCKThrs .

[0186] Exemplarily, the condition of step D11 may be: the vehicle is in a braking state, and max{|α fl |、|α fr |、|α rl |、|α rr |}<α TurnThrs , and V X >V lckThrs , and in D or R gear.

[0187] Exemplarily, in order to avoid the influence of the vehicle driving and braking mode, speed, and steering state on the locking state detection, when the conditions mentioned in step D11 are met, the locking detection is enabled. Exemplarily, the locking detection is steps D12 to D16. If the conditions mentioned in step D11 are not met, it can jump to step S306.

[0188] Step D12: For each of the driven wheels, if the fault flag of the driven wheel is FALSE, obtain the speed drop gradient of the driven wheel at each periodic interval.

[0189] Exemplarily, the multiple driven wheels include: a left driven wheel on the front axle (i.e., a left driven wheel on the first axle), a right driven wheel on the front axle (i.e., a right driven wheel on the first axle), a left driven wheel on the rear axle (i.e., a left driven wheel on the fourth axle), and a right driven wheel on the rear axle (i.e., a right driven wheel on the fourth axle).

[0190] Exemplarily, the calculation formula for the speed drop gradient of the left driven wheel of the front axle is as follows:

[0191] , where the speed of the left driven wheel of the front axle is n whlfl , the rotation speed of the right driven wheel of the front axle is n whlfr , the speed of the left driven wheel of the rear axle is n whlrl , the speed of the right driven wheel of the rear axle is n whlrr For example, n is the number of cycles of the current time, and m is the window length of the mean filter. For example, the value of m can be 5.

[0192] Exemplarily, the calculation formula for the speed drop gradient of the right driven wheel of the front axle is as follows:

[0193] .

[0194] Exemplarily, the calculation formula for the speed drop gradient of the left driven wheel of the rear axle is as follows:

[0195] .

[0196] Exemplarily, the calculation formula for the speed drop gradient of the right driven wheel of the rear axle is as follows:

[0197] .

[0198] Step D13: If the minimum value of the speed reduction gradient of the plurality of driven wheels in each period interval is greater than the preset speed reduction gradient threshold value n whlgrdThrs , determine that the initial locking levels of the multiple driven wheels are zero, otherwise, determine that the initial locking levels of the multiple driven wheels are 1.

[0199] For example, if min{n whlflgrd 、n whlfrgrd 、n whlrlgrd 、n whlrrgrd}>n whlgrdThrs , then the initial locking level is zero, that is, the locking level of the left driven wheel of the front axle is E fllck =0, locking level of the right driven wheel of the front axle is E frlck =0, locking level of the left driven wheel of the rear axle is E rllck =0, locking level of the right driven wheel of the rear axle is E rrlck =0; if min{n whlflgrd 、n whlfrgrd 、n whlrlgrd 、n whlrrgrd}≤n whlgrdThrs , then the initial locking level is 1, that is, the locking level of the left driven wheel of the front axle is E fllck =1, locking level of the right driven wheel of the front axle is E frlck=1, locking level of the left driven wheel of the rear axle is E rllck =1, locking level of the right driven wheel of the rear axle E rrlck =1.

[0200] Next, it is further determined whether the wheel has a tendency to lock. In the process of detecting whether the wheel has a tendency to lock, the integrated vehicle speed mentioned in step B11 to step B12 needs to be used to draw a double threshold envelope.

[0201] Step D14: For each of the driven wheels, if the speed of the driven wheel is greater than the vehicle speed L1 level lower limit V dwnL1 And the initial locking level of the driven wheel is zero, and it is determined that the locking level of the driven wheel is zero.

[0202] It is understandable that if the speed of the driven wheel is greater than the lower limit V of the vehicle speed L1 level dwnL1 And if the initial locking level of the driven wheel is zero, it is considered that no wheel locking occurs, and the locking level of the driven wheel is determined to be zero.

[0203] Step D15: For each of the driven wheels, if the speed of the driven wheel is greater than or equal to the vehicle speed L2 level lower limit V dwnL2 and is less than or equal to the vehicle speed L1 level lower limit V dwnL1 , determine that the locking level of the driven wheel is 1.

[0204] It is understandable that if the speed of the driven wheel is between V dwnL2 and V dwnL1 If the driven wheel has a locking level of 1, then the locked wheel is considered to have a locking level of 1.

[0205] Step D16: For each of the driven wheels, if the speed of the driven wheel is less than the vehicle speed L1 level lower limit V dwnL2 , determine that the locking level of the driven wheel is 2.

[0206] If the speed of the driven wheel is less than V dwnL2 , it is considered that the driven wheel has secondary locking, and the locking level of the driven wheel is determined to be 2.

[0207] It can be understood that no matter whether the driven wheel has a locking tendency or not, the following step S306 needs to be performed.

[0208] Step S306: If the locking level of at least one of the driven wheels is not 0, based on the longitudinal projections of the mounting points of the multiple driven wheels in the vehicle body coordinate system and the initial speed weights of the multiple driven wheels, the updated speed weights corresponding to the multiple driven wheels are calculated.

[0209] Exemplarily, the locking level of at least one driven wheel is not 0, which means that the locking level of at least one driven wheel is 1 or 2. At this time, the wheel speeds are redistributed according to the wheel speed deviation.

[0210] Exemplarily, the calculation formula of the longitudinal projection of multiple driven wheels is as follows:

[0211] Longitudinal projection V of the left driven wheel of the front axle fl The calculation formula is as follows: .

[0212] For example, the longitudinal projection V of the right driven wheel of the front axle is fr The calculation formula is as follows: .

[0213] For example, the longitudinal projection V of the left driven wheel of the rear axle is rl The calculation formula is as follows: .

[0214] Exemplarily, the longitudinal projection V of the right driven wheel of the rear axle rr The calculation formula is as follows: .

[0215] in, is the yaw angular velocity, L fl , L fr , L rl , L rr are the distances from the Yaw sensor installation point to the installation points of each wheel. For example, the yaw angular velocity adopts a right-hand system, that is, counterclockwise rotation is the positive direction.

[0216] Exemplarily, the formula for calculating the sum of the deviations of the longitudinal speeds of each wheel relative to the longitudinal reference vehicle speed is as follows:

[0217] .

[0218] Exemplarily, the updated speed weight may be calculated based on the deviation ratio, and the calculation formula for calculating the updated speed weight corresponding to each driven wheel is as follows.

[0219] Updated speed weight W of the left driven wheel on the front axle fl The calculation formula is as follows:

[0220] .

[0221] Updated speed weight W of the right driven wheel on the front axle fr The calculation formula is as follows:

[0222] .

[0223] Updated speed weight W of the left driven wheel on the rear axle rlThe calculation formula is as follows:

[0224] .

[0225] Updated speed weight W of the right driven wheel of the rear axle rr The calculation formula is as follows:

[0226] .

[0227] Step S307: obtaining a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights corresponding to the plurality of driven wheels.

[0228] For example, the corrected longitudinal acceleration integrated vehicle speed weight W ACC =1-(W fl +W fr +W rl +W rr ).

[0229] Step S308: Calculate the equivalent vehicle speed V based on the updated speed weights of the plurality of driven wheels, the speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed. whl .

[0230] Exemplary, equivalent vehicle speed .

[0231] Step S309: Based on the preset vehicle speed weight, the preset motor-converted vehicle speed weight, and the equivalent vehicle speed V whl And the motor converted vehicle speed V mtrspd , calculate the vehicle speed V in the fusion transition phase mrg .

[0232] For example, the vehicle speed V is converted by the motor mtrspd The updated speed weight of the equivalent vehicle speed of the driven wheel is used to ensure the smoothness of the vehicle speed during the switching process of the vehicle speed calculation mode.

[0233] For example, the vehicle speed weight W whl The calculation formula is as follows: For example, C is a gain coefficient for adjusting the upward trend of the function curve, and in this embodiment, C=200 is defined. bl is the lower boundary of the fusion interval speed, V bh is the upper boundary of the fusion interval velocity.

[0234] For example, the motor-converted vehicle speed weight W mtr The calculation formula is as follows: mtr =1-W whl .

[0235] Exemplarily, the vehicle speed V in the fusion transition phase mrg =W whl ×V whl + W mtr× V mtrspd .

[0236] Step S310: Obtain the target vehicle speed calculation mode.

[0237] Step S311: Find the target vehicle speed corresponding to the target vehicle speed calculation mode from the preset correspondence between the vehicle speed calculation mode and the vehicle speed, where the vehicle speed is the corrected longitudinal acceleration integrated vehicle speed V ACC , the equivalent vehicle speed V whl , the motor converted vehicle speed V mtrspd , the vehicle speed V in the fusion transition phase mrg and the driving wheel equivalent speed V Drvspd Any one of .

[0238] Exemplarily, vehicle speed calculation mode C mode The corresponding relationship with vehicle speed is as follows:

[0239] Target speed .

[0240] The embodiment of the present application provides a method for calculating the vehicle speed fusion of a multi-axis vehicle, which obtains the motor-converted vehicle speed, the equivalent vehicle speed of the driving wheel, the corrected longitudinal acceleration integral vehicle speed, the updated speed weights of multiple driven wheels, and the corrected longitudinal acceleration integral vehicle speed weight; based on the updated speed weights of multiple driven wheels, the current cycle speeds of multiple driven wheels, the corrected longitudinal acceleration integral vehicle speed weights, and the corrected longitudinal acceleration integral vehicle speed, the equivalent vehicle speed is calculated; based on the preset vehicle speed weight, the preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed, the vehicle speed in the fusion transition stage is calculated; the target vehicle speed calculation mode is obtained; and from the corresponding relationship between the preset vehicle speed calculation mode and the vehicle speed, the target vehicle speed corresponding to the target vehicle speed calculation mode is searched.

[0241] The embodiment of the present application can be applied to various low-adhesion road conditions, and accurately calculate the target vehicle speed according to the information of each sensor under different vehicle fault conditions, providing stable and accurate input parameters for vehicle control to the maximum extent. At the same time, the method proposed in the present application can ensure that the calculation result is stable and there is no speed jump phenomenon, and the calculation time meets the performance requirements of general vehicle controllers.

[0242] In an optional implementation, the integrated vehicle speed may be obtained to draw a dual threshold envelope for subsequent wheel locking judgment. The specific process includes the following steps B11 to B12.

[0243] Step B11: Integrating the vehicle speed V based on the corrected longitudinal acceleration ACC , the preset vehicle speed L1 level speed upper limit gain, the preset vehicle speed L1 level speed lower limit gain, the preset L1 level speed upper and lower limit envelope width, and the vehicle speed L1 level upper limit V is calculated upL1 And the lower limit of vehicle speed L1 level V dwnL1 .

[0244] For example, the vehicle speed L1 level upper limit V upL1 =max{C u1 ×V ACC , V ACC +V TolL1}. Among them, the speed upper limit gain of vehicle speed L1 is C u1 The preset L1 speed upper and lower limit envelope width is V TolL1 .

[0245] For example, the vehicle speed L1 level lower limit V dwnL1 =max{C l1 ×V ACC , V ACC -V TolL1}. Among them, the speed lower limit gain of vehicle speed L1 is C l1 .

[0246] Step B12: Integrating the vehicle speed V based on the corrected longitudinal acceleration ACC , the preset L2 speed upper limit gain, the preset L2 speed lower limit gain, the preset L2 speed upper and lower limit envelope width, and the L2 speed upper and lower limit V are calculated. upL2 And the lower limit of vehicle speed L2 level V dwnL2 .

[0247] For example, the vehicle speed L2 level upper limit V upL2 =max{C u2 ×V ACC , V ACC +V TolL2}. Among them, the speed upper limit gain of vehicle speed L2 is C u2 The preset L2 speed upper and lower limit envelope width is V TolL2 .

[0248] For example, the vehicle speed L2 level lower limit V dwnL2 =max{C l2 ×V ACC , V ACC -V TolL2}. Among them, the speed lower limit gain of vehicle speed L2 is C l2 .

[0249] The process of obtaining the vehicle speed calculation mode is described below. The process includes the following steps E11 to E15.

[0250] Step E11: If the fault flags of the multiple motors, the fault flags corresponding to the multiple driving wheels, and the fault flags corresponding to the multiple driven wheels are all FALSE, or if the minimum value of the absolute values ​​of the steering angles of the multiple driven wheels is less than or equal to the preset steering angle threshold and the number of fault flags of the multiple driven wheels that are TRUE is within a preset range, the vehicle speed calculation mode is determined based on the equivalent vehicle speed.

[0251] For example, the preset turning angle threshold can be α Turn Representation.

[0252] Exemplarily, the preset range may be determined based on actual conditions, which will not be elaborated here. For example, the preset range is [1, 3].

[0253] Exemplarily, determining the vehicle speed calculation mode based on the equivalent vehicle speed includes the following steps E111 to E113.

[0254] In order to avoid the delay in wheel speed sensor acquisition when the vehicle is at low speed and the influence of the dead zone of the wheel speed sensor on the vehicle speed calculation, a fusion calculation will be performed, which can be specifically as shown in steps E111 to E113.

[0255] Step E111: If the equivalent vehicle speed V whl Less than the preset fusion interval speed lower boundary V bl , and the slip state of multiple motors is no slip, determining that the vehicle speed calculation mode is the second mode.

[0256] Step E112: If the equivalent vehicle speed V whl Greater than or equal to the preset fusion interval speed lower limit V bl And less than or equal to the preset fusion interval speed upper boundary V bh , and the slip state of multiple motors is no slip, determining that the vehicle speed calculation mode is the third mode.

[0257] Step E113: If the equivalent vehicle speed V whl Greater than the preset fusion interval speed upper limit V bh , determine that the vehicle speed calculation mode is the first mode.

[0258] Step E12: If the minimum value of the absolute values ​​of the rotation angles of the multiple driven wheels is less than or equal to the preset rotation angle threshold and the number of fault flags of the multiple driven wheels that is TRUE is greater than the preset range and the fault flags of the multiple motors are all FALSE, determine that the vehicle speed calculation mode is the second mode.

[0259] Step E13: If the minimum value of the absolute values ​​of the rotation angles of the multiple driven wheels is greater than the preset rotation angle threshold and the fault flags of the left driven wheel of the first bridge and the left driven wheel of the fourth bridge among the fault flags of the multiple motors are both TRUE or the fault flags of the right driven wheel of the first bridge and the right driven wheel of the fourth bridge are both TRUE, and the fault flags of the multiple motors are not all TRUE, determine that the vehicle speed calculation mode is the second mode.

[0260] Step E14: If the fault flags of the plurality of motors, the fault flags of the plurality of driving wheels, and the fault flags of the plurality of driven wheels are all TRUE, it is determined that the vehicle speed calculation mode is the zeroth mode.

[0261] Step E15: If the fault flags of the plurality of driven wheels are all TRUE, the fault flags of the plurality of motors are all TRUE, and the fault flags of the plurality of driving wheels are all FALSE, it is determined that the vehicle speed calculation mode is the fourth mode.

[0262] In an optional implementation, the plurality of motors include a first motor and a second motor, and step S301 specifically includes the following steps F01 to F11.

[0263] Step F01: If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the torque T of the first motor is f and the second motor T r The sum of the torques is greater than or equal to the first preset torque threshold; or, the fault flags of the multiple motors are all FALSE and the rotation directions of the first motor and the second motor are different, and the minimum speed of the first motor and the second motor is determined to be the equivalent speed.

[0264] Exemplarily, the first preset torque threshold may be T Drvgrd The first preset torque threshold is the minimum effective torque gradient of the motor, which is used to determine whether the motor generates effective positive torque. Exemplarily, the first preset torque threshold is 50Nm.

[0265] Step F01 includes two conditions. One condition is that the fault flags of the first motor and the second motor are both FALSE and the rotation directions of the first motor and the second motor are the same and T f +T r ≥T Drvgrd ; Another condition is: the fault flags of the first motor and the second motor are both FALSE and the rotation directions of the first motor and the second motor are different.

[0266] For example, the equivalent speed n mtr =min{n f , nr}, where the speed of the first motor is n f , the speed of the second motor is n r .

[0267] Step F02: If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is less than the first preset torque threshold, determine that the maximum speed of the first motor and the second motor is the equivalent speed.

[0268] It is understandable that at high torque, the motor speed is slightly higher than the actual vehicle speed due to the slip rate or skidding, so the minimum speed of the first motor and the second motor is determined as the equivalent speed. At low torque, the slip rate has little effect on the motor speed, especially at the beginning, which may be affected by the sensor dead zone. At this time, the maximum speed of the first motor and the second motor is relatively accurate.

[0269] For example, the equivalent speed n mtr =max{n f , n r}.

[0270] Step F03: Based on the equivalent speed, determine the motor speed weights corresponding to the first motor and the second motor respectively.

[0271] Exemplarily, the motor speed weight of the first motor is denoted by W fmtr The motor speed weight of the second motor is represented by W rmtr Characterization. Then the motor speed weight calculation formula is as follows:

[0272] .

[0273] Step F04: If the fault flags of the plurality of motors are all FALSE, a first speed gradient of the first motor at a plurality of cycle intervals and a second speed gradient of the second motor at a plurality of cycle intervals are obtained.

[0274] For example, the first speed gradient n fgrd The calculation formula is as follows:

[0275] .

[0276] For example, the second speed gradient n rgrd The calculation formula is as follows:

[0277] .

[0278] In summary, the speed change rate, i.e., the gradient, is estimated by calculating the difference in motor speed in different time windows.

[0279] Step F05: Determine the maximum value of the first speed gradient and the second speed gradient as the maximum driving speed gradient.

[0280] For example, the maximum drive speed gradient n grd =max{n fgrd , n rgrd}.

[0281] Step F06: If the maximum driving speed gradient is greater than or equal to a first preset gradient threshold, determine that the motor speed weights corresponding to the first motor and the second motor are zero.

[0282] Exemplarily, the first preset gradient threshold is n slipgrd Representation.

[0283] If the maximum driving speed gradient ≥ n slipgrd , it is recognized that the first motor and the second motor are currently slipping, and the speeds of the first motor and the second motor cannot accurately represent the speed of the vehicle, so let W fmtr =0,W rmtr =0.

[0284] Step F07: If the maximum driving speed gradient is less than the first preset gradient threshold, determine the absolute value of the difference between the speed of the first motor and the speed of the second motor as the front and rear motor speed separation.

[0285] If the maximum driving speed gradient is less than n slipgrd , it is recognized that there is no slippage of the first motor and the second motor at present, and it is necessary to further calculate the speed separation degree n of the front and rear motors diff =|n f -n r |.

[0286] Step F08: If the front and rear motor speed separation is less than the preset speed separation threshold, and the maximum driving speed gradient is less than the first preset gradient threshold, determine that the motor speed weights corresponding to the first motor and the second motor are 1 respectively.

[0287] Exemplarily, the preset speed separation threshold can be expressed as n mdiffThrs Representation.

[0288] If the speed separation of the front and rear motors is n diff <n mdiffThrs And the maximum driving speed gradient n grd <n slipgrd , it is considered that the first motor and the second motor do not slip.

[0289] Step F09: If the speed separation degree of the front and rear motors is greater than or equal to a preset speed separation threshold, determine that the motor speed weights corresponding to the first motor and the second motor are zero.

[0290] If the speed separation of the front and rear motors is n diff ≥n mdiffThrs , it is considered that the first motor and / or the second motor are currently slipping, and the first motor and / or the second motor cannot accurately represent the vehicle speed.

[0291] Step F10: If the motor speed weights of the first motor and the second motor are both zero, determine the motor converted vehicle speed V mtrspd is 0.

[0292] It can be understood that, through steps F01 to F09, multiple motor speed weights of the first motor and multiple motor speed weights of the second motor can be obtained.

[0293] Step F11: If at least one of the motor speed weight of the first motor and the motor speed weight of the second motor is not zero, the motor converted vehicle speed V is calculated based on the tire rolling radius, the motor-to-wheel end transmission ratio, the driving front axle left wheel angle, the driving front axle right wheel angle, the driving rear axle left wheel angle and the driving rear axle right wheel angle, the motor speed weight of the first motor and the motor speed weight of the second motor. mtrspd .

[0294] For example, the motor-converted vehicle speed V is calculated mtrspd The formula is as follows:

[0295] , where r is the tire rolling radius and i is the transmission ratio from the motor to the wheel end.

[0296] In an optional implementation, the plurality of driving wheels include a front axle left driving wheel, a front axle right driving wheel, a rear axle left driving wheel and a rear axle right driving wheel; the implementation method of step S302 includes the following steps G01 to G10.

[0297] Step G01: for each of the driving wheels, if the fault flag of the driving wheel is TRUE, determine that the driving wheel speed weight of the driving wheel is zero.

[0298] Exemplarily, if the fault flag of the driving wheel is FALSE, the driving wheel speed weight of the driving wheel is 1; if the fault flag of the driving wheel is TRUE, the driving wheel speed weight of the driving wheel is 0.

[0299] Step G02: For each of the driving wheels, if the fault flag of the driving wheel is FALSE, determine the absolute value of the difference between the rotation speed of the left driving wheel of the front axle and the rotation speed of the right driving wheel of the front axle, which is the front axle driving wheel rotation speed difference.

[0300] Front axle drive wheel speed difference n Drvfdiff =|n Drvfl -n Drvfr |.n Drvfl is the left wheel speed of the front drive axle, n Drvfr It is the speed of the right wheel of the front drive axle.

[0301] Step G03: Determine the absolute value of the difference between the rotation speed of the left driving wheel of the rear axle and the rotation speed of the right driving wheel of the rear axle, which is the rear axle driving wheel rotation speed difference.

[0302] Since the transfer case may cause the drive wheel to distribute all the driving torque to the low-resistance side when on a dual-road or when one wheel is suspended, causing the wheel speed on one side to be too high, the speed difference between the left and right wheels of the drive axle is used to determine whether there is a fault.

[0303] Transfer Case is an important gear transmission device, usually used in four-wheel drive vehicles or multi-axle drive vehicles. Its main function is to distribute the power output of the transmission to each drive axle.

[0304] Rear axle drive wheel speed difference n Drvrdiff =|n Drvrl -n Drvrr |.n Drvrl is the left wheel speed of the rear drive axle, n Drvrr It is the speed of the right wheel of the rear drive axle.

[0305] Step G04: If the speed difference of the front axle driving wheels is greater than a preset speed threshold, determine that the driving wheel speed weights corresponding to the front axle left driving wheel and the front axle right driving wheel are zero.

[0306] If the front axle drive wheel speed difference n Drvfdiff >Preset speed threshold n DdiffThrs , it is believed that the wheel speed of the front axle drive wheel cannot accurately represent the vehicle speed.

[0307] Step G05: If the front axle drive wheel speed difference is less than or equal to the preset speed threshold, determine that the drive wheel speed weights corresponding to the front axle left drive wheel and the front axle right drive wheel are 1.

[0308] If the front axle driving wheel speed is less than or equal to the preset speed threshold n DdiffThrs , it is believed that the wheel speed of the front axle driving wheel can accurately represent the vehicle speed.

[0309] Step G06: If the rear axle drive wheel speed difference is greater than the preset speed threshold, determine that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are zero.

[0310] Step G07: If the rear axle drive wheel speed difference is less than or equal to the preset speed threshold, determine that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are 1.

[0311] Step G08: Calculate the average longitudinal rotation speed of the front axle based on the rotation speed of the left driving wheel of the front axle, the driving wheel rotation speed weight of the left driving wheel of the front axle, the rotation speed of the right driving wheel of the front axle and the driving wheel rotation speed weight of the right driving wheel of the front axle.

[0312] For example, the average longitudinal speed of the front axle n Drvf The calculation formula is as follows:

[0313] .

[0314] Step G09: Calculate the average longitudinal speed of the rear axle based on the driving wheel speed weight of the left driving wheel of the rear axle, the driving wheel speed weight of the right driving wheel of the rear axle, the speed of the left driving wheel of the rear axle and the speed of the right driving wheel of the rear axle.

[0315] For example, the average longitudinal speed of the rear axle n Drvr The calculation formula is as follows:

[0316] .

[0317] Step G10: Calculate the driving wheel equivalent vehicle speed V based on the average longitudinal speed of the front axle and the average longitudinal speed of the rear axle Drvspd .

[0318] Exemplarily, the calculation formula of the driving wheel equivalent vehicle speed is as follows:

[0319] .

[0320] A method for calculating the fusion speed of a multi-axle vehicle provided in an embodiment of the present application is introduced above. A device for executing the method for calculating the fusion speed of a multi-axle vehicle is introduced below.

[0321] See also Figure 4 , Figure 4 This is a schematic diagram of a structure of a multi-axle vehicle speed fusion calculation device provided in an embodiment of the present application. Figure 4 As shown, the vehicle speed fusion calculation device for a multi-axle vehicle includes:

[0322] A first acquisition module 401 is used to acquire the motor-converted vehicle speed based on the fault flags of the multiple motors, the motor equivalent speeds, and the slip states of the multiple motors;

[0323] A first calculation module 402, configured to calculate an equivalent vehicle speed of a driving wheel based on the fault flags respectively corresponding to the plurality of driving wheels and the rotation speeds respectively corresponding to the plurality of driving wheels;

[0324] The second acquisition module 403 is used to obtain a corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to the plurality of driven wheels, and the vehicle speed of each cycle corresponding to the plurality of driven wheels;

[0325] A first determination module 404 is used to determine initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the plurality of driven wheels in each cycle respectively corresponding to the plurality of driven wheels;

[0326] A second determination module 405 is configured to determine, for any of the driven wheels, a locking level of the driven wheel based on the rotation speed of each cycle of the driven wheel if the driven wheel is in a locked state and the initial rotation speed weight of the driven wheel is not 0;

[0327] A second calculation module 406 is configured to calculate, if the locking level of at least one of the driven wheels is not 0, updated speed weights corresponding to the plurality of driven wheels respectively based on the longitudinal projections of the mounting points of the plurality of driven wheels in the vehicle body coordinate system and the initial speed weights of the plurality of driven wheels;

[0328] A third acquisition module 407 is used to acquire a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights respectively corresponding to the plurality of driven wheels;

[0329] A third calculation module 408, configured to calculate an equivalent vehicle speed based on the updated speed weights of the plurality of driven wheels, the speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed;

[0330] A fourth calculation module 409 is used to calculate the vehicle speed in the fusion transition phase based on a preset vehicle speed weight, a preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed;

[0331] The fourth acquisition module 410 is used to acquire a target vehicle speed calculation mode;

[0332] The search module 411 is used to search for the target vehicle speed corresponding to the target vehicle speed calculation mode from the corresponding relationship between the preset vehicle speed calculation mode and the vehicle speed, and the vehicle speed is any one of the corrected longitudinal acceleration integrated vehicle speed, the equivalent vehicle speed, the motor converted vehicle speed, the fusion transition stage vehicle speed and the driving wheel equivalent vehicle speed.

[0333] In an optional implementation, the fourth acquisition module includes:

[0334] A first determining unit is configured to determine the vehicle speed calculation mode based on the equivalent vehicle speed if the fault flags of the plurality of motors, the fault flags corresponding to the plurality of driving wheels, and the fault flags corresponding to the plurality of driven wheels are all FALSE, or if the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to a preset rotation angle threshold and the number of fault flags of the plurality of driven wheels that are TRUE is within a preset range;

[0335] a second determining unit, configured to determine that the vehicle speed calculation mode is the second mode if the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to the preset rotation angle threshold value and the number of the fault flags of the plurality of driven wheels being TRUE is greater than the preset range and the fault flags of the plurality of motors are all FALSE;

[0336] a third determining unit, configured to determine that the vehicle speed calculation mode is the second mode if the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is greater than the preset rotation angle threshold and the fault flags of the left driven wheel of the first bridge and the left driven wheel of the fourth bridge among the fault flags of the plurality of motors are both TRUE or the fault flags of the right driven wheel of the first bridge and the right driven wheel of the fourth bridge are both TRUE, and the fault flags of the plurality of motors are not all TRUE;

[0337] a fourth determining unit, configured to determine that the vehicle speed calculation mode is a zeroth mode if the fault flags of the plurality of motors, the fault flags of the plurality of driving wheels, and the fault flags of the plurality of driven wheels are all TRUE;

[0338] The fifth determination unit is used to determine that the vehicle speed calculation mode is the fourth mode if the fault flags of the plurality of driven wheels are all TRUE, the fault flags of the plurality of motors are all TRUE, and the fault flags of the plurality of driving wheels are all FALSE.

[0339] In an optional implementation, the first determining unit includes:

[0340] A first determining subunit, configured to determine that the vehicle speed calculation mode is a second mode if the equivalent vehicle speed is less than a preset lower boundary of the fusion interval speed and the slip state of the plurality of motors is no slip;

[0341] A second determination subunit is configured to determine that the vehicle speed calculation mode is a third mode if the equivalent vehicle speed is greater than or equal to the preset fusion interval speed lower boundary and less than or equal to the preset fusion interval speed upper boundary, and the slip state of the plurality of motors is no slip;

[0342] The third determining subunit is configured to determine that the vehicle speed calculation mode is the first mode if the equivalent vehicle speed is greater than the preset upper boundary of the fusion interval speed.

[0343] In an optional implementation, the plurality of motors include a first motor and a second motor, and the first acquisition module includes:

[0344] a fourth determination subunit, configured to determine that the minimum speed of the first motor and the second motor is the equivalent speed if the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is greater than or equal to a first preset torque threshold, or if the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have different rotation directions;

[0345] a fifth determination subunit, configured to determine that the maximum speed of the first motor and the second motor is the equivalent speed if the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is less than the first preset torque threshold;

[0346] a sixth determining subunit, configured to determine motor speed weights corresponding to the first motor and the second motor respectively based on the equivalent speed;

[0347] A first acquisition subunit is configured to acquire a first speed gradient of the first motor at multiple periodic intervals and a second speed gradient of the second motor at multiple periodic intervals if the fault flags of the multiple motors are all FALSE;

[0348] a seventh determining subunit, configured to determine a maximum value of the first speed gradient and the second speed gradient as a maximum driving speed gradient;

[0349] an eighth determination subunit, configured to determine that the motor speed weights corresponding to the first motor and the second motor respectively are zero if the maximum driving speed gradient is greater than or equal to a first preset gradient threshold;

[0350] a ninth determination subunit, configured to determine, if the maximum driving speed gradient is less than the first preset gradient threshold, an absolute value of a difference between a speed of the first motor and a speed of the second motor as a front and rear motor speed separation degree;

[0351] a tenth determining subunit, configured to determine that the motor speed weights corresponding to the first motor and the second motor are 1 if the speed separation degree of the front and rear motors is less than the preset speed separation threshold and the maximum driving speed gradient is less than the first preset gradient threshold;

[0352] an eleventh determining subunit, configured to determine that the motor speed weights corresponding to the first motor and the second motor respectively are zero if the speed separation degree of the front and rear motors is greater than or equal to a preset speed separation threshold;

[0353] A twelfth determination subunit, configured to determine that the motor-converted vehicle speed is 0 if the motor speed weights of the first motor and the motor speed weights of the second motor are both zero;

[0354] The first calculation subunit is used to calculate the motor-converted vehicle speed based on the tire rolling radius, the motor-to-wheel end transmission ratio, the driving front axle left wheel angle, the driving front axle right wheel angle, the driving rear axle left wheel angle and the driving rear axle right wheel angle, the motor speed weight of the first motor and the motor speed weight of the second motor if at least one of the motor speed weight of the first motor and the motor speed weight of the second motor is not zero.

[0355] In an optional implementation, the plurality of driving wheels include a front axle left driving wheel, a front axle right driving wheel, a rear axle left driving wheel, and a rear axle right driving wheel; and the first calculation module includes:

[0356] a sixth determining unit, configured to determine, for each of the driving wheels, if the fault flag of the driving wheel is TRUE, that the driving wheel speed weight of the driving wheel is zero;

[0357] a seventh determination unit, for each of the driving wheels, if the fault flag of the driving wheel is FALSE, determining an absolute value of a difference between a rotation speed of the left driving wheel of the front axle and a rotation speed of the right driving wheel of the front axle as a front axle driving wheel rotation speed difference;

[0358] an eighth determination unit, configured to determine an absolute value of a difference between a rotation speed of a left driving wheel of the rear axle and a rotation speed of a right driving wheel of the rear axle, as a rear axle driving wheel rotation speed difference;

[0359] A ninth determining unit, configured to determine that the driving wheel speed weights corresponding to the left driving wheel and the right driving wheel of the front axle are zero if the front axle driving wheel speed difference is greater than a preset speed threshold;

[0360] a tenth determining unit, configured to determine that the driving wheel speed weights corresponding to the left driving wheel and the right driving wheel of the front axle are 1 if the front axle driving wheel speed difference is less than or equal to the preset speed threshold;

[0361] an eleventh determining unit, configured to determine that the driving wheel speed weights corresponding to the left driving wheel and the right driving wheel of the rear axle are zero if the rear axle driving wheel speed difference is greater than the preset speed threshold;

[0362] A twelfth determining unit is used to determine that the driving wheel speed weights corresponding to the left driving wheel and the right driving wheel of the rear axle are 1 if the rear axle driving wheel speed difference is less than or equal to the preset speed threshold;

[0363] a first calculation unit, configured to calculate an average longitudinal rotation speed of the front axle based on the rotation speed of the left driving wheel of the front axle, the driving wheel rotation speed weight of the left driving wheel of the front axle, the rotation speed of the right driving wheel of the front axle, and the driving wheel rotation speed weight of the right driving wheel of the front axle;

[0364] a second calculation unit, configured to calculate an average longitudinal speed of the rear axle based on the driving wheel speed weight of the left driving wheel of the rear axle, the driving wheel speed weight of the right driving wheel of the rear axle, the speed of the left driving wheel of the rear axle, and the speed of the right driving wheel of the rear axle;

[0365] The third calculation unit is used to calculate the driving wheel equivalent vehicle speed based on the average longitudinal rotation speed of the front axle and the average longitudinal rotation speed of the rear axle.

[0366] In an optional implementation, the plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges; and the second acquisition module includes:

[0367] A first acquisition unit, used for acquiring real-time longitudinal acceleration;

[0368] a setting unit, configured to set, for each cycle, an initial longitudinal acceleration of the cycle to 0 if the vehicle is in a braking state and the real-time longitudinal acceleration of the vehicle is greater than |a first preset acceleration threshold value| when the gear position of the vehicle is the D gear or the real-time longitudinal acceleration of the vehicle is less than -|a first preset acceleration threshold value| when the gear position of the vehicle is the R gear, and the real-time longitudinal acceleration is less than a second preset acceleration threshold value;

[0369] A fourteenth determining unit is used to determine the maximum value among the equivalent vehicle speed of each cycle of the left driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the left driven wheel of the fourth bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the fourth bridge, and the vehicle speed before each cycle as the acceleration integration starting point;

[0370] The fourth calculation unit is used to calculate the corrected longitudinal acceleration integrated vehicle speed based on the acceleration integration starting point and the initial longitudinal acceleration of each cycle.

[0371] In an optional implementation, the method further includes:

[0372] a fifth calculation module, configured to calculate the vehicle speed L1 level upper limit and the vehicle speed L1 level lower limit based on the corrected longitudinal acceleration integrated vehicle speed, a preset vehicle speed L1 level upper limit gain, a preset vehicle speed L1 level lower limit gain, and a preset L1 level speed upper and lower limit envelope width;

[0373] A sixth calculation module is used to calculate the vehicle speed V based on the corrected longitudinal acceleration integral ACC , the preset L2 level speed upper limit gain, the preset L2 level speed lower limit gain, the preset L2 level speed upper and lower limit envelope widths, and the L2 level speed upper and lower limit are calculated to obtain the L2 level speed upper and lower limit.

[0374] In an optional implementation, the plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges; and the first determining module includes:

[0375] A fifteenth determining unit is configured to determine, for each of the driven wheels, if the fault flag of the driven wheel is TRUE, that the initial speed weight of the driven wheel is 0;

[0376] The sixteenth determination unit is used to determine, for each of the driven wheels, that the initial speed weight of the driven wheel is 0 if the fault flag of the driven wheel is FALSE and the difference between the speed of the current cycle and the speed of the previous cycle is greater than or equal to a preset speed threshold, otherwise the initial speed weight is determined to be 1.

[0377] In an optional implementation, the second determining module includes:

[0378] The enabling unit is used to, if the vehicle is in a braking state, and the maximum absolute value of the driven wheel rotation angle of the plurality of driven wheels is less than a preset steering judgment angle threshold, and the real-time vehicle speed V x The speed is greater than a preset detection speed threshold, and the gear position of the vehicle is D gear or R gear, enabling locking detection;

[0379] A second acquisition unit is used for acquiring, for each of the driven wheels, a speed drop gradient of the driven wheel at each periodic interval if the fault flag of the driven wheel is FALSE;

[0380] a seventeenth determining unit, configured to determine that the initial locking levels of the plurality of driven wheels are zero if the minimum value of the speed decrease gradient of the plurality of driven wheels at each period interval is greater than a preset speed decrease gradient threshold, and otherwise, determine that the initial locking levels of the plurality of driven wheels are 1;

[0381] An eighteenth determining unit, configured to determine, for each of the driven wheels, that the locking level of the driven wheel is zero if the rotation speed of the driven wheel is greater than the lower limit of the vehicle speed L1 level and the initial locking level of the driven wheel is zero;

[0382] A nineteenth determining unit is configured to determine, for each of the driven wheels, if the rotation speed of the driven wheel is greater than or equal to the vehicle speed L2 level lower limit and less than or equal to the vehicle speed L1 level lower limit, that the locking level of the driven wheel is 1;

[0383] The twentieth determining unit is configured to determine, for each of the driven wheels, that the locking level of the driven wheel is 2 if the rotation speed of the driven wheel is less than the lower limit of the vehicle speed L1 level.

[0384] The present application also provides an electronic device in an embodiment. Figure 5 As shown, it shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiment of the present application. The electronic device in the embodiment of the present application may include but is not limited to fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, etc. Figure 5 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0385] like Figure 5 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage device 508 to a random access memory (RAM) 503. When the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 503. The processing device 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0386] Typically, the following devices may be connected to the I / O interface 505: an input device 506 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 507 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 508 including, for example, a memory card, a hard disk, etc.; and a communication device 509. The communication device 509 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 5 An electronic device having various devices is shown, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.

[0387] Also provided in an embodiment of the present application is a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any one of the vehicle speed fusion calculation methods for a multi-axle vehicle provided in an embodiment of the present application.

[0388] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any one of the vehicle speed fusion calculation methods for a multi-axle vehicle provided in an embodiment of the present application.

[0389] It should also be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

[0390] Through the description of the above implementation mode, the technicians in the field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation mode in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, a U disk, a mobile hard disk, a ROM, a RAM, a disk or an optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, a training device, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0391] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0392] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, training device, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

Claims

1. A method for calculating the vehicle speed fusion of a multi-axle vehicle, characterized in that: include: Based on the fault flags of multiple motors, the equivalent speeds of the motors, and the slip states of the multiple motors, the motor-converted vehicle speeds are obtained; Based on the fault flags respectively corresponding to the plurality of driving wheels and the rotation speeds respectively corresponding to the plurality of driving wheels, an equivalent vehicle speed of the driving wheels is calculated; Obtaining a corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels; Determining initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the respective cycles respectively corresponding to the plurality of driven wheels; For any of the driven wheels, if the driven wheel is in a locked state and the initial speed weight of the driven wheel is not 0, determining the locking level of the driven wheel based on the speed of each cycle of the driven wheel; If the locking level of at least one of the driven wheels is not 0, based on the longitudinal projections of the mounting points of the plurality of driven wheels in the vehicle body coordinate system and the initial speed weights of the plurality of driven wheels, the updated speed weights corresponding to the plurality of driven wheels are calculated; Obtaining a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights respectively corresponding to the plurality of driven wheels; Calculating an equivalent vehicle speed based on updated speed weights of the plurality of driven wheels, speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed; Calculating the vehicle speed in the fusion transition phase based on a preset vehicle speed weight, a preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed; Get the target vehicle speed calculation mode; From the correspondence between the preset vehicle speed calculation mode and the vehicle speed, the target vehicle speed corresponding to the target vehicle speed calculation mode is searched, and the vehicle speed is any one of the corrected longitudinal acceleration integral vehicle speed, the equivalent vehicle speed, the motor converted vehicle speed, the fusion transition stage vehicle speed and the driving wheel equivalent vehicle speed.

2. The vehicle speed fusion calculation method for multi-axle vehicles according to claim 1 is characterized in that: The vehicle speed calculation mode is obtained, including: If the fault flags of the plurality of motors, the fault flags corresponding to the plurality of driving wheels, and the fault flags corresponding to the plurality of driven wheels are all FALSE, or if the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to the preset rotation angle threshold and the number of fault flags of the plurality of driven wheels that are TRUE is within a preset range, the vehicle speed calculation mode is determined based on the equivalent vehicle speed; If the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is less than or equal to the preset rotation angle threshold value and the number of the fault flags of the plurality of driven wheels being TRUE is greater than the preset range and the fault flags of the plurality of motors are all FALSE, determining that the vehicle speed calculation mode is the second mode; If the minimum value of the absolute values ​​of the rotation angles of the plurality of driven wheels is greater than the preset rotation angle threshold and the fault flags of the left driven wheel of the first bridge and the left driven wheel of the fourth bridge among the fault flags of the plurality of motors are both TRUE or the fault flags of the right driven wheel of the first bridge and the right driven wheel of the fourth bridge are both TRUE, and the fault flags of the plurality of motors are not all TRUE, determining that the vehicle speed calculation mode is the second mode; If the fault flags of the plurality of motors, the fault flags of the plurality of driving wheels, and the fault flags of the plurality of driven wheels are all TRUE, determining that the vehicle speed calculation mode is the zeroth mode; If the fault flags of the plurality of driven wheels are all TRUE, the fault flags of the plurality of motors are all TRUE, and the fault flags of the plurality of driving wheels are all FALSE, it is determined that the vehicle speed calculation mode is the fourth mode.

3. The method for calculating the vehicle speed fusion of a multi-axle vehicle according to claim 2, characterized in that: The determining the vehicle speed calculation mode based on the equivalent vehicle speed includes: If the equivalent vehicle speed is less than the preset lower boundary of the fusion interval speed, and the slip state of the plurality of motors is no slip, determining that the vehicle speed calculation mode is the second mode; If the equivalent vehicle speed is greater than or equal to the preset lower boundary of the fusion interval speed and less than or equal to the preset upper boundary of the fusion interval speed, and the slip state of the plurality of motors is no slip, determining that the vehicle speed calculation mode is the third mode; If the equivalent vehicle speed is greater than the preset upper boundary of the fusion interval speed, the vehicle speed calculation mode is determined to be the first mode.

4. The vehicle speed fusion calculation method for multi-axle vehicles according to claim 1, characterized in that: The multiple motors include a first motor and a second motor, and obtaining the motor-converted vehicle speed based on the fault flags of the multiple motors, the motor equivalent speeds, and the slip states of the multiple motors includes: If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is greater than or equal to a first preset torque threshold, or the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have different rotation directions, it is determined that the minimum speed of the first motor and the second motor is the equivalent speed; If the fault flags of the plurality of motors are all FALSE and the first motor and the second motor have the same rotation direction, and the sum of the torque of the first motor and the torque of the second motor is less than the first preset torque threshold, determine that the maximum speed of the first motor and the second motor is the equivalent speed; Based on the equivalent speed, determining motor speed weights corresponding to the first motor and the second motor respectively; If the fault flags of the plurality of motors are all FALSE, obtaining a first speed gradient of the first motor at a plurality of periodic intervals and a second speed gradient of the second motor at a plurality of periodic intervals; Determine the maximum value of the first speed gradient and the second speed gradient as the maximum driving speed gradient; If the maximum driving speed gradient is greater than or equal to a first preset gradient threshold, determining that the motor speed weights corresponding to the first motor and the second motor are zero; If the maximum driving speed gradient is less than the first preset gradient threshold, determining the absolute value of the difference between the speed of the first motor and the speed of the second motor as the front and rear motor speed separation; If the speed separation of the front and rear motors is less than a preset speed separation threshold, and the maximum driving speed gradient is less than the first preset gradient threshold, determining that the motor speed weights corresponding to the first motor and the second motor are 1 respectively; If the speed separation degree of the front and rear motors is greater than or equal to the preset speed separation threshold, determining that the motor speed weights corresponding to the first motor and the second motor are zero; If the motor speed weights of the first motor are both zero and the motor speed weights of the second motor are both zero, determining that the motor-converted vehicle speed is 0; If at least one of the motor speed weight of the first motor and the motor speed weight of the second motor is not zero, the motor-converted vehicle speed is calculated based on the tire rolling radius, the motor-to-wheel end transmission ratio, the driven front axle left wheel angle, the driven front axle right wheel angle, the driven rear axle left wheel angle and the driven rear axle right wheel angle, the motor speed weight of the first motor and the motor speed weight of the second motor.

5. The vehicle speed fusion calculation method for multi-axle vehicles according to claim 1, characterized in that: The plurality of driving wheels include a front axle left driving wheel, a front axle right driving wheel, a rear axle left driving wheel and a rear axle right driving wheel; The calculating the equivalent vehicle speed of the driving wheels based on the fault flags respectively corresponding to the plurality of driving wheels and the rotation speeds respectively corresponding to the plurality of driving wheels comprises: For each of the driving wheels, if the fault flag of the driving wheel is TRUE, determining that the driving wheel speed weight of the driving wheel is zero; For each of the driving wheels, if the fault flag of the driving wheel is FALSE, determine the absolute value of the difference between the rotation speed of the left driving wheel of the front axle and the rotation speed of the right driving wheel of the front axle, which is the front axle driving wheel rotation speed difference; Determine the absolute value of the difference between the rotation speed of the left driving wheel of the rear axle and the rotation speed of the right driving wheel of the rear axle, which is the rear axle driving wheel rotation speed difference; If the speed difference of the front axle driving wheels is greater than a preset speed threshold, determining that the driving wheel speed weights corresponding to the left front axle driving wheel and the right front axle driving wheel are zero; If the front axle drive wheel speed difference is less than or equal to the preset speed threshold, determining that the drive wheel speed weights corresponding to the front axle left drive wheel and the front axle right drive wheel are 1; If the rear axle drive wheel speed difference is greater than the preset speed threshold, determining that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are zero; If the rear axle drive wheel speed difference is less than or equal to the preset speed threshold, determining that the drive wheel speed weights corresponding to the rear axle left drive wheel and the rear axle right drive wheel are 1; Based on the rotation speed of the left driving wheel of the front axle, the driving wheel rotation speed weight of the left driving wheel of the front axle, the rotation speed of the right driving wheel of the front axle and the driving wheel rotation speed weight of the right driving wheel of the front axle, the average longitudinal rotation speed of the front axle is calculated; Based on the driving wheel speed weight of the left driving wheel of the rear axle, the driving wheel speed weight of the right driving wheel of the rear axle, the speed of the left driving wheel of the rear axle, and the speed of the right driving wheel of the rear axle, the average longitudinal speed of the rear axle is calculated; The driving wheel equivalent vehicle speed is calculated based on the average longitudinal rotation speed of the front axle and the average longitudinal rotation speed of the rear axle.

6. The method for calculating the vehicle speed fusion of a multi-axle vehicle according to any one of claims 1 to 5, characterized in that: The plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges; The step of obtaining the corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels comprises: Get real-time longitudinal acceleration; For each cycle, if the vehicle is in a braking state, and the real-time longitudinal acceleration of the vehicle is greater than |a first preset acceleration threshold value| when the gear position of the vehicle is D gear, or the real-time longitudinal acceleration of the vehicle is less than -|a first preset acceleration threshold value| when the gear position of the vehicle is R gear, and the real-time longitudinal acceleration is less than the second preset acceleration threshold value, the initial longitudinal acceleration of the cycle is set to 0; Determine the maximum value among the equivalent vehicle speed of each cycle of the left driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the first bridge, the equivalent vehicle speed of each cycle of the left driven wheel of the fourth bridge, the equivalent vehicle speed of each cycle of the right driven wheel of the fourth bridge, and the vehicle speed before each cycle as the acceleration integration starting point; The corrected longitudinal acceleration integrated vehicle speed is calculated based on the acceleration integration starting point and the initial longitudinal acceleration of each cycle.

7. The method for calculating the vehicle speed fusion of a multi-axle vehicle according to claim 6, characterized in that: Also includes: Based on the corrected longitudinal acceleration integrated vehicle speed, the preset vehicle speed L1 level upper limit gain, the preset vehicle speed L1 level lower limit gain, and the preset L1 level speed upper and lower limit envelope widths, the vehicle speed L1 level upper limit and the vehicle speed L1 level lower limit are calculated; Based on the corrected longitudinal acceleration integrated vehicle speed, the preset L2 level speed upper limit gain, the preset L2 level speed lower limit gain, and the preset L2 level speed upper and lower limit envelope widths, the L2 level speed upper limit and the L2 level speed lower limit are calculated.

8. The vehicle speed fusion calculation method for multi-axle vehicles according to claim 7 is characterized in that: The plurality of driven wheels include a left driven wheel on one bridge, a right driven wheel on one bridge, a left driven wheel on four bridges, and a right driven wheel on four bridges; The determining of initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of each cycle respectively corresponding to the plurality of driven wheels comprises: For each of the driven wheels, if the fault flag of the driven wheel is TRUE, determining the initial speed weight of the driven wheel to be 0; For each of the driven wheels, if the fault flag of the driven wheel is FALSE, and the difference between the speed of the current cycle of the driven wheel and the speed of the previous cycle is greater than or equal to the preset speed threshold, the initial speed weight of the driven wheel is determined to be 0, otherwise the initial speed weight is determined to be 1.

9. The method for calculating the vehicle speed fusion of a multi-axle vehicle according to claim 8, characterized in that: If the driven wheel is in a locked state and the initial speed weight of the driven wheel is not 0, determining the locking level of the driven wheel based on the speed of each cycle of the driven wheel includes: If the vehicle is in a braking state, and the maximum value of the absolute values ​​of the driven wheel turning angles of the plurality of driven wheels is less than a preset steering judgment angle threshold, and the real-time speed of the vehicle is greater than a preset detection speed threshold, and the gear position of the vehicle is D gear or R gear, locking detection is enabled; For each of the driven wheels, if the fault flag of the driven wheel is FALSE, obtaining the speed drop gradient of the driven wheel at each period interval; If the minimum value of the speed drop gradient of the plurality of driven wheels in each period interval is greater than the preset speed drop gradient threshold, the initial locking level of the plurality of driven wheels is determined to be zero; otherwise, the initial locking level of the plurality of driven wheels is determined to be 1; For each of the driven wheels, if the rotation speed of the driven wheel is greater than the lower limit of the vehicle speed L1 level and the initial locking level of the driven wheel is zero, determining that the locking level of the driven wheel is zero; For each of the driven wheels, if the rotation speed of the driven wheel is greater than or equal to the vehicle speed L2 level lower limit and less than or equal to the vehicle speed L1 level lower limit, determining the locking level of the driven wheel to be 1; For each of the driven wheels, if the rotation speed of the driven wheel is less than the lower limit of the vehicle speed L1 level, the locking level of the driven wheel is determined to be 2.

10. A vehicle speed fusion calculation device for multi-axle vehicles, characterized in that: include: A first acquisition module is used to acquire the motor-converted vehicle speed based on the fault flags of the multiple motors, the motor equivalent speeds, and the slip states of the multiple motors; A first calculation module, configured to calculate an equivalent vehicle speed of a driving wheel based on fault flags corresponding to a plurality of driving wheels and rotation speeds corresponding to the plurality of driving wheels; A second acquisition module is used to obtain a corrected longitudinal acceleration integrated vehicle speed based on the longitudinal acceleration of each cycle, the equivalent vehicle speed of each cycle corresponding to each of the plurality of driven wheels, and the vehicle speed of each cycle corresponding to each of the plurality of driven wheels; A first determination module, configured to determine initial speed weights of the plurality of driven wheels based on the fault flags respectively corresponding to the plurality of driven wheels and the speeds of the respective cycles respectively corresponding to the plurality of driven wheels; a second determination module, configured to determine, for any of the driven wheels, a locking level of the driven wheel based on the rotation speed of each cycle of the driven wheel if the driven wheel is in a locked state and the initial rotation speed weight of the driven wheel is not 0; A second calculation module is configured to calculate, if the locking level of at least one of the driven wheels is not 0, updated speed weights corresponding to the plurality of driven wheels respectively based on the longitudinal projections of the mounting points of the plurality of driven wheels in the vehicle body coordinate system and the initial speed weights of the plurality of driven wheels; A third acquisition module is used to acquire a corrected longitudinal acceleration integrated vehicle speed weight based on the updated speed weights respectively corresponding to the plurality of driven wheels; a third calculation module, configured to calculate an equivalent vehicle speed based on the updated speed weights of the plurality of driven wheels, the speeds of the plurality of driven wheels in the current cycle, the corrected longitudinal acceleration integrated vehicle speed weight, and the corrected longitudinal acceleration integrated vehicle speed; A fourth calculation module, configured to calculate the vehicle speed in the fusion transition phase based on a preset vehicle speed weight, a preset motor-converted vehicle speed weight, the equivalent vehicle speed, and the motor-converted vehicle speed; A fourth acquisition module, used for acquiring a target vehicle speed calculation mode; A search module is used to search for a target vehicle speed corresponding to the target vehicle speed calculation mode from a correspondence between a preset vehicle speed calculation mode and a vehicle speed, wherein the vehicle speed is any one of the corrected longitudinal acceleration integrated vehicle speed, the equivalent vehicle speed, the motor-converted vehicle speed, the fusion transition phase vehicle speed and the drive wheel equivalent vehicle speed.

Images