Vehicle control system speed determination methods, equipment, devices, media, and vehicles

Abstract

This invention discloses a method, device, apparatus, medium, and vehicle for determining vehicle speed in a vehicle control system. The method includes acquiring the vehicle's mass, air resistance, front wheel steering angle, yaw rate, second-largest wheel speed change over 1 second, and lateral speed at the current sampling moment; the wheel lateral force and first wheel longitudinal force of each wheel at the current sampling moment; the average wheel acceleration of each wheel during the current sampling period; the first characteristic adhesion coefficient and the first adhesion coefficient limit of each wheel at the previous sampling moment; the estimated longitudinal speed change over 1 second and the estimated longitudinal speed of the vehicle at the previous sampling moment; and using all the acquired parameters, calculations are performed to finally determine the estimated lateral speed of the vehicle at the current sampling moment. This invention can be widely applied in the field of data processing technology.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and in particular to a method, device, apparatus, storage medium, and vehicle for determining vehicle speed in a vehicle control system. Background Technology

[0002] Vehicle Motion Control (VMC) is one of the core technologies of autonomous driving. Based on instructions from the decision-making and planning layer, VMC controls the vehicle to travel along a reference trajectory by combining vehicle status and environmental information. To ensure driving safety and comprehensively improve the driving experience, accurate and reliable vehicle speed information is required across all scenarios to achieve refined control of vehicle motion.

[0003] In related technologies, existing speed determination methods have limited coverage of scenarios and are not comprehensive enough, resulting in weak engineering applicability. Furthermore, some speed determination algorithms suffer from low accuracy and insufficient real-time performance. Therefore, there are still technical problems that need to be solved in these related technologies. Summary of the Invention

[0004] The purpose of this invention is to at least partially solve one of the technical problems existing in the prior art.

[0005] Therefore, one objective of this invention is to provide a method, device, apparatus, storage medium, and vehicle for determining vehicle speed in a vehicle control system. This solution can improve the accuracy and real-time performance of speed determination during driving.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted in this embodiment of the invention includes: a vehicle speed determination method for a vehicle control system, comprising the following steps: acquiring the vehicle mass, the air resistance, front wheel steering angle, yaw rate, second largest wheel speed change over 1 second, and lateral speed of the vehicle at the current sampling time, the wheel lateral force and first wheel longitudinal force of each wheel at the current sampling time, the average wheel acceleration of each wheel in the current sampling period, the first characteristic adhesion coefficient and the first adhesion coefficient limit of each wheel at the previous sampling time, the estimated value of the longitudinal speed change over 1 second of the vehicle at the previous sampling time, and the estimated value of the longitudinal speed of the vehicle at the previous sampling time; and based on the air resistance, the vehicle mass, the front wheel steering angle, and the first wheel speed change over 1 second, the vehicle speed determination method for a vehicle control system, comprising the following steps: acquiring the air resistance, the vehicle mass, the front wheel steering angle, and the first wheel speed change over 1 second, and the lateral speed of the vehicle at the current sampling time; and acquiring the lateral force and first wheel longitudinal force of each wheel at the current sampling time; and acquiring the lateral force and first wheel longitudinal force of each wheel at the current sampling period, and acquiring the lateral force and first wheel longitudinal force of each wheel at the current sampling period; ... The longitudinal acceleration of the vehicle at the current sampling time is determined by the longitudinal force of the wheels, the lateral force of the wheels, the change in the second largest wheel speed in 1 second, the yaw rate, and the lateral speed. The first longitudinal acceleration of the vehicle at the current sampling time is determined based on the longitudinal acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient. The observed longitudinal speed of the vehicle at the current sampling time is determined based on the average wheel acceleration of each wheel. The estimated longitudinal speed of the vehicle at the current sampling time is determined based on the observed longitudinal speed, the estimated change in longitudinal speed in 1 second, and the first longitudinal acceleration. The estimated lateral speed of the vehicle at the current sampling time is determined based on the estimated longitudinal speed and the lateral speed.

[0007] In addition, the vehicle speed determination method of the vehicle control system according to the above embodiments of the present invention may also have the following additional technical features:

[0008] Further, in this embodiment of the invention, determining the longitudinal acceleration of the vehicle at the current sampling moment based on the air resistance, the vehicle mass, the front wheel steering angle, the first wheel longitudinal force, the wheel lateral force, the second largest wheel speed change in 1 second, the yaw rate, and the lateral vehicle speed includes: determining the second longitudinal acceleration of the vehicle at the current sampling moment based on the air resistance, the vehicle mass, the front wheel steering angle, the first wheel longitudinal force, and the wheel lateral force; and determining the longitudinal acceleration based on the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the second largest wheel speed change in 1 second.

[0009] Further, in this embodiment of the invention, determining the second longitudinal acceleration of the vehicle at the current sampling moment based on the air resistance, the vehicle mass, the front wheel steering angle, the first wheel longitudinal force, and the wheel lateral force includes: for any one wheel, determining the second wheel longitudinal force based on the front wheel steering angle, the first wheel longitudinal force, and the wheel lateral force; summing the second wheel longitudinal forces of each wheel to obtain the longitudinal force of the vehicle at the current sampling moment; and determining the second longitudinal acceleration of the vehicle based on the longitudinal force, the air resistance, and the vehicle mass.

[0010] Furthermore, in this embodiment of the invention, the air resistance is obtained through the following steps: obtaining the longitudinal speed of the vehicle at the current sampling time; and determining the air resistance based on the longitudinal speed and a preset second calibration value.

[0011] Furthermore, in this embodiment of the invention, the longitudinal force of the first wheel is obtained through the following steps: acquiring the wheel acceleration, wheel radius, wheel-end driving torque, and wheel-end braking torque at the current sampling time; determining the wheel-end net torque based on the wheel-end driving torque and wheel-end braking torque; and determining the longitudinal force of the first wheel based on the wheel acceleration, the wheel radius, and the wheel-end net torque.

[0012] Further, in this embodiment of the invention, determining the longitudinal slope acceleration based on the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed includes: when the vehicle is in a forward-moving state at the current sampling time, inputting the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed into a first formula to obtain the longitudinal slope acceleration; the first formula is:

[0013] V1 = A - VM * VN - ax1,

[0014] When the vehicle is not moving forward at the current sampling time, the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed are input into the second formula to obtain the longitudinal slope acceleration; the second formula is:

[0015] V1 = -A - VM * VN - ax1,

[0016] In the first formula and the second formula, A is the second largest wheel speed change in 1s, VM is the yaw rate of the whole vehicle, VN is the lateral speed of the whole vehicle, and ax1 is the second longitudinal acceleration.

[0017] Further, in this embodiment of the invention, determining the first longitudinal acceleration of the vehicle at the current sampling time based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient includes: determining a second adhesion coefficient limit for each wheel at the current sampling time based on the first adhesion coefficient limit and the longitudinal slope acceleration; determining a second characteristic adhesion coefficient for each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit; determining a second wheel longitudinal force for each wheel at the current sampling time based on the second characteristic adhesion coefficient; and determining the first longitudinal acceleration of the vehicle at the current sampling time based on the second wheel longitudinal force.

[0018] Furthermore, in this embodiment of the invention, determining the second adhesion coefficient limit for each wheel at the current sampling time based on the first adhesion coefficient limit and the longitudinal slope acceleration includes: determining the adhesion coefficient offset for each wheel at the current sampling time based on the longitudinal slope acceleration; and determining the second adhesion coefficient limit based on the adhesion coefficient offset and the first adhesion coefficient limit.

[0019] Furthermore, in this embodiment of the invention, determining the adhesion coefficient offset of each wheel at the current sampling time based on the longitudinal slope acceleration includes: determining the slope offset based on the vehicle speed at the current sampling time and the longitudinal slope acceleration; and determining the adhesion coefficient offset based on the lateral dynamic offset at the current sampling time, the slope offset, and the preset base offset.

[0020] Further, in this embodiment of the invention, determining the second characteristic adhesion coefficient of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit includes: determining the 1s change in wheel acceleration of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the wheel vertical force of each wheel at the current sampling time; determining the predicted wheel acceleration value and the corrected wheel acceleration value of each wheel at the current sampling time based on the 1s change in wheel acceleration, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius; determining the slip ratio of each wheel at the current sampling time based on the predicted wheel acceleration value and the corrected wheel acceleration value; and determining the second characteristic adhesion coefficient based on the slip ratio and the second adhesion coefficient limit.

[0021] Further, in this embodiment of the invention, determining the wheel acceleration change of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the wheel vertical force of each wheel at the current sampling time includes: determining the wheel longitudinal force of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the wheel vertical force; and determining the wheel acceleration change of each wheel at the current sampling time based on the wheel longitudinal force, the wheel radius of each wheel, the wheel net torque of each wheel at the current sampling time, and the wheel moment of inertia of each wheel at the current sampling time.

[0022] Furthermore, in this embodiment of the invention, determining the predicted wheel acceleration value and the corrected wheel acceleration value for each wheel at the current sampling time based on the 1s change in wheel acceleration, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius includes: determining the predicted wheel acceleration value based on the 1s change in wheel acceleration and the wheel acceleration; and determining the corrected wheel acceleration value based on the predicted wheel acceleration value, the wheel speed, and the wheel radius.

[0023] Further, in this embodiment of the invention, determining the slip ratio of each wheel at the current sampling moment based on the predicted wheel acceleration value and the corrected wheel acceleration value includes: determining the wheel acceleration of each wheel at the current sampling moment based on the predicted wheel acceleration value and the corrected wheel acceleration value; determining the calculated wheel speed of each wheel at the current sampling moment based on the wheel acceleration; and determining the slip ratio of each wheel at the current sampling moment based on the calculated wheel speed and the longitudinal vehicle speed of the wheel.

[0024] Further, in this embodiment of the invention, determining the second characteristic adhesion coefficient based on the slip ratio and the second adhesion coefficient limit includes: determining a second characteristic adhesion theoretical coefficient based on the slip ratio and tire stiffness; when the second characteristic adhesion theoretical coefficient is less than or equal to the second adhesion coefficient limit, using the second characteristic adhesion theoretical coefficient as the second characteristic adhesion coefficient; when the second characteristic adhesion theoretical coefficient is greater than the second adhesion coefficient limit, using the second adhesion coefficient limit as the second characteristic adhesion coefficient.

[0025] Further, in this embodiment of the invention, determining the longitudinal vehicle speed observation value at the current sampling moment based on the average wheel acceleration of each wheel includes: for any wheel, determining the cumulative value of wheel acceleration variance and the wheel acceleration accelerator corresponding to the current wheel at several sampling moments in the current sampling period based on the average wheel acceleration and the first wheel acceleration of the current wheel at several sampling moments in the current sampling period; determining the average wheel acceleration and the cumulative value of wheel acceleration variance based on the wheel acceleration; determining the wheel acceleration confidence level of each wheel based on the first wheel acceleration, the average wheel acceleration, and the cumulative value of wheel acceleration variance; and determining the wheel acceleration confidence level based on the wheel acceleration. The reliability of wheel acceleration for each wheel is determined by the mean wheel acceleration and the cumulative variance of wheel acceleration. The reliability of wheel speed for each wheel is determined based on the reliability of wheel acceleration, wheel acceleration, wheel vertical force, wheel speed and longitudinal speed difference, and wheel acceleration and vehicle acceleration difference. When the vehicle is not in a counter-steering state and not in a handbrake-engaged state, the vehicle speed observation value for the current sampling time is determined based on the reliability of wheel speed for each wheel and the wheel speed of each wheel at the current sampling time. The longitudinal speed observation value for the current sampling time is determined based on the vehicle speed observation value, the upper speed limit, and the lower speed limit.

[0026] Further, in this embodiment of the invention, determining the wheel speed reliability of each wheel based on the wheel acceleration reliability, the wheel acceleration reliability, the wheel vertical force reliability, the wheel speed and longitudinal speed difference reliability, and the wheel acceleration and vehicle acceleration difference reliability includes: for any wheel, taking the minimum reliability among the wheel acceleration reliability, the wheel acceleration reliability, the wheel vertical force reliability, the wheel speed and longitudinal speed difference reliability, and the wheel acceleration and vehicle acceleration difference reliability as the wheel speed reliability of the corresponding wheel.

[0027] Furthermore, in this embodiment of the invention, determining the wheel acceleration confidence level of each wheel based on the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of the wheel acceleration includes determining a first confidence level based on the first wheel acceleration and the mean wheel acceleration; determining a second confidence level based on the cumulative variance of the wheel acceleration; and taking the smaller confidence level between the first confidence level and the second confidence level as the wheel acceleration confidence level.

[0028] Further, in this embodiment of the invention, determining the longitudinal vehicle speed observation value of the whole vehicle at the current sampling time based on the observed vehicle speed value, the upper limit of vehicle speed value, and the lower limit of vehicle speed value includes: when the observed vehicle speed value is greater than the lower limit of vehicle speed value and less than the upper limit of vehicle speed value, using the observed vehicle speed value as the longitudinal vehicle speed observation value of the whole vehicle at the current sampling time; when the observed vehicle speed value is less than or equal to the lower limit of vehicle speed value, using the lower limit of vehicle speed value as the longitudinal vehicle speed observation value of the whole vehicle at the current sampling time; when the observed vehicle speed value is greater than or equal to the upper limit of vehicle speed value, using the upper limit of vehicle speed value as the longitudinal vehicle speed observation value of the whole vehicle at the current sampling time.

[0029] Further, in this embodiment of the invention, the step of determining the estimated longitudinal speed of the vehicle at the current sampling time based on the observed longitudinal speed, the estimated longitudinal speed change over 1 second, and the first longitudinal acceleration is as follows: The observed longitudinal speed change over 1 second at the current sampling time is determined based on the first longitudinal acceleration; when the current sampling time is the i-th time, the estimated longitudinal speed of the vehicle at the corresponding current sampling time is obtained using the following formula:

[0030] VI i =VI i-1 +k 21 *(VJ-VM i-1 )+k 22 *(VK-VI i-1 ),

[0031] Among them, VI i VM represents the estimated longitudinal speed of the vehicle at the current sampling time. i-1 VI is the estimated value of the longitudinal vehicle speed change over 1 second. i-1 The estimated longitudinal vehicle speed at the previous sampling time; VJ is the observed longitudinal vehicle speed change over 1 second, VK is the observed longitudinal vehicle speed; k 21 k is the first calibration coefficient at the current sampling time. 22 is the second calibration coefficient at the current sampling time, i > 1.

[0032] Further, in this embodiment of the invention, determining the longitudinal vehicle speed change in 1s at the current sampling time based on the first longitudinal acceleration includes: when the vehicle is in a forward-moving state at the current sampling time, the longitudinal vehicle speed change in 1s satisfies the following formula:

[0033] VJ = ax² + VM * VN,

[0034] When the vehicle is not moving forward at the current sampling time, the observed value of the longitudinal vehicle speed change over 1 second satisfies the following formula:

[0035] VJ = ax² - VM * VN,

[0036] Where VJ is the observed change in longitudinal vehicle speed over 1 second, ax2 is the first longitudinal acceleration of the vehicle at the current sampling time, VM is the yaw rate of the vehicle at the current sampling time, and VN is the lateral speed of the vehicle at the current sampling time.

[0037] Further, in this embodiment of the invention, determining the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and the estimated lateral speed of the vehicle at the current sampling time includes: determining the longitudinal slip ratio and the second wheel lateral force of each wheel at the current sampling time based on the estimated longitudinal speed and the lateral speed of the vehicle at the current sampling time; determining the second wheel longitudinal force of each wheel at the current sampling time based on the longitudinal slip ratio; determining the lateral acceleration of the vehicle at the current sampling time based on the vehicle mass, the front wheel steering angle, the second wheel longitudinal force, and the second wheel lateral force of each wheel at the current sampling time; determining the lateral speed change of the vehicle in 1 second at the current sampling time based on the lateral acceleration, the estimated longitudinal speed, and the yaw rate; and determining the estimated lateral speed of the vehicle at the current sampling time based on the lateral speed change in 1 second.

[0038] On the other hand, embodiments of the present invention also provide a vehicle speed determination device for a vehicle control system, comprising:

[0039] The first processing unit is used to acquire the vehicle mass, the air resistance, front wheel steering angle, yaw rate, 1s change of the second largest wheel speed and lateral speed of the vehicle at the current sampling time, the wheel lateral force and the first wheel longitudinal force of each wheel at the current sampling time, the average wheel acceleration of each wheel in the current sampling period, the first characteristic adhesion coefficient of each wheel and the first adhesion coefficient limit of each wheel at the previous sampling time, the estimated value of the 1s change of the longitudinal speed of the vehicle at the previous sampling time and the estimated value of the longitudinal speed of the vehicle at the previous sampling time.

[0040] The second processing unit is used to determine the longitudinal slope acceleration of the vehicle at the current sampling time based on the air resistance, the vehicle mass, the front wheel steering angle, the longitudinal force of the first wheel, the lateral force of the wheel, the 1s change of the second largest wheel speed, the yaw rate, and the lateral vehicle speed.

[0041] The third processing unit is used to determine the first longitudinal acceleration of the vehicle at the current sampling time based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient.

[0042] The fourth processing unit is used to determine the longitudinal speed observation value of the whole vehicle at the current sampling time based on the average wheel acceleration of each wheel.

[0043] The fifth processing unit is used to determine the estimated longitudinal speed of the whole vehicle at the current sampling time based on the longitudinal speed observation value, the estimated longitudinal speed change value in 1 second, and the first longitudinal acceleration.

[0044] The sixth processing unit is used to determine the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and the estimated lateral speed of the vehicle at the current sampling time.

[0045] On the other hand, the present invention also provides a vehicle speed determination device for a vehicle control system, comprising:

[0046] At least one processor;

[0047] At least one memory for storing at least one program;

[0048] When the at least one program is executed by the at least one processor, the at least one processor implements the vehicle speed determination method of the vehicle control system as described above.

[0049] In addition, the present invention provides a storage medium storing processor-executable instructions, which, when executed by a processor, are used to perform the vehicle speed determination method of the vehicle control system as described above.

[0050] In addition, the present invention also provides a vehicle, including a vehicle control system speed determination device or a vehicle control system speed determination equipment as described above.

[0051] The advantages and beneficial effects of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention:

[0052] This invention can obtain the vehicle's mass, air resistance, front wheel angle, yaw rate, 1-second change in the second largest wheel speed, and lateral speed at the current sampling moment; the wheel lateral force and first wheel longitudinal force at the current sampling moment; the average wheel acceleration of each wheel during the current sampling period; the first characteristic adhesion coefficient and the first adhesion coefficient limit of each wheel at the previous sampling moment; the estimated 1-second change in the vehicle's longitudinal speed at the previous sampling moment; and the estimated longitudinal speed of the vehicle at the previous sampling moment. Based on air resistance, vehicle mass, front wheel angle, first wheel longitudinal force, wheel lateral force, and second largest wheel speed... The longitudinal acceleration of the vehicle at the current sampling time is determined by the 1-second change in speed, yaw rate, and lateral speed. The first longitudinal acceleration of the vehicle at the current sampling time is determined based on the longitudinal acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient. The observed longitudinal speed of the vehicle at the current sampling time is determined based on the average wheel acceleration of each wheel. The estimated longitudinal speed of the vehicle at the current sampling time is determined based on the observed longitudinal speed, the estimated 1-second change in longitudinal speed, and the first longitudinal acceleration. The estimated lateral speed of the vehicle at the current sampling time is determined based on the estimated longitudinal speed and lateral speed. This invention can improve the accuracy and real-time performance of speed calculation during autonomous driving. Attached Figure Description

[0053] Figure 1 This is a schematic diagram illustrating the steps of a vehicle speed determination method for a vehicle control system in a specific embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of the overall scheme of the vehicle control system speed determination method in another specific embodiment of the present invention;

[0055] Figure 3 This is a schematic diagram of the process for calculating longitudinal slope acceleration in another specific embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of the process for determining the first longitudinal acceleration of the vehicle at the current sampling moment in a specific embodiment of the present invention;

[0057] Figure 5 This is a schematic diagram illustrating the steps of determining the first longitudinal acceleration of the vehicle at the current sampling moment based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient in a specific embodiment of the present invention.

[0058] Figure 6 This is a schematic diagram illustrating the steps of determining the longitudinal speed observation value of the whole vehicle at the current sampling time based on the average wheel acceleration of each wheel in a specific embodiment of the present invention.

[0059] Figure 7This is a flowchart illustrating the process of determining longitudinal vehicle speed observations in another specific embodiment of the present invention;

[0060] Figure 8 This is a schematic diagram illustrating the steps of determining the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and lateral speed of the vehicle at the current sampling time in a specific embodiment of the present invention.

[0061] Figure 9 This is a flowchart illustrating the process of determining the estimated lateral vehicle speed in a specific embodiment of the present invention;

[0062] Figure 10 This is a schematic diagram of the vehicle speed determination device of the vehicle control system in a specific embodiment of the present invention;

[0063] Figure 11 This is a schematic diagram of the vehicle speed determination device in a specific embodiment of the present invention. Detailed Implementation

[0064] The following detailed description, in conjunction with the accompanying drawings, illustrates the principles and processes of the vehicle speed determination method, equipment, device, storage medium, and vehicle in the vehicle control system of the present invention.

[0065] Reference Figure 1 as well as Figure 2 The present invention can provide a method for determining vehicle speed in a vehicle control system. Figure 1 This is a schematic diagram illustrating the steps of the vehicle speed determination method in the vehicle control system of the present invention. Figure 2 This is a schematic diagram of an overall scheme for another vehicle control system speed determination method according to the present invention. Figure 1 In this process, the vehicle speed determination method of the vehicle control system may include, but is not limited to, steps S101-S106.

[0066] S101. Obtain the vehicle mass, air resistance, front wheel steering angle, yaw rate, second largest wheel speed change over 1 second, and lateral speed of the vehicle at the current sampling time, wheel lateral force and first wheel longitudinal force of each wheel at the current sampling time, mean wheel acceleration of each wheel in the current sampling period, first characteristic adhesion coefficient of each wheel and first adhesion coefficient limit of each wheel at the previous sampling time, estimated longitudinal speed change over 1 second of the vehicle at the previous sampling time, and estimated longitudinal speed of the vehicle at the previous sampling time.

[0067] It is understandable that the current sampling period includes the current sampling moment, the previous sampling moment, and several sampling moments prior to the previous sampling moment; the current sampling moment can be the last sampling moment among multiple sampling moments in the current sampling period. Air resistance, front wheel steering angle, yaw rate, second-largest wheel speed change over 1 second, and lateral vehicle speed are vehicle parameters collected or calculated at the current sampling moment; the lateral force of each wheel and the first longitudinal force of each wheel are wheel parameters collected or calculated at the current sampling moment; the average wheel acceleration of each wheel in the current sampling period can be the average wheel acceleration of each wheel in the current sampling period; the estimated longitudinal speed change over 1 second and the estimated longitudinal speed of the entire vehicle are vehicle parameters collected or calculated at the previous sampling moment; the first characteristic adhesion coefficient of each wheel and the first adhesion coefficient limit of each wheel at the previous sampling moment are wheel parameters collected or calculated at the previous sampling moment.

[0068] In some feasible embodiments of the present invention, the processor can first establish a wired connection with the camera equipment or other processors on the vehicle. Through the wired or wireless connection, the processor can acquire the vehicle's mass, the vehicle's air resistance, front wheel steering angle, yaw rate, second largest wheel speed change over 1 second, and lateral speed at the current sampling time, the wheel lateral force and first wheel longitudinal force of each wheel at the current sampling time, the average wheel acceleration of each wheel in the current sampling period, the first characteristic adhesion coefficient of each wheel and the first adhesion coefficient limit of each wheel at the previous sampling time, the estimated value of the longitudinal speed change over 1 second, and the estimated longitudinal speed of the entire vehicle.

[0069] It should be noted that the aforementioned wired connection methods can include connections between mobile devices and the processing module, connections between the processing module and hardware devices, and wired connections between the processing module and other currently known or future-developed devices. The aforementioned wireless connection methods can include, but are not limited to, 3G / 4G / 5G connections, WiFi connections, Bluetooth connections, WiMAX connections, Zigbee connections, UWB (Ultra Wide Band) connections, and other currently known or future-developed wireless connection methods. The energy management module and the battery detection module can be an integrated system or two separate systems that each implement their corresponding functions.

[0070] S102. Based on air resistance, vehicle mass, front wheel steering angle, longitudinal force of the first wheel, lateral force of the wheel, change in the second largest wheel speed in 1 second, yaw rate, and lateral vehicle speed, determine the longitudinal slope acceleration of the vehicle at the current sampling moment.

[0071] It is understood that the first wheel longitudinal force and wheel lateral force in this embodiment refer to the wheel longitudinal force and wheel lateral force corresponding to each wheel respectively. That is, the number of first wheel longitudinal forces required in the data processing of this embodiment is the same as the number of wheels, and the number of wheel lateral forces required is the same as the number of wheels.

[0072] In some feasible embodiments of the present invention, after obtaining air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, wheel lateral force, second largest wheel speed change in 1 second, yaw rate, and lateral vehicle speed, the processor can determine the longitudinal slope acceleration of the vehicle at the current sampling time based on the air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, wheel lateral force, second largest wheel speed change in 1 second, yaw rate, and lateral vehicle speed.

[0073] S103. Determine the first longitudinal acceleration of the vehicle at the current sampling moment based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient.

[0074] It is understandable that any wheel at the previous sampling time can correspond to either a first adhesion coefficient limit or a characteristic adhesion coefficient. In some embodiments, the first adhesion coefficient limits corresponding to any two wheels in the vehicle can be equal. In some embodiments, the first adhesion coefficient limits corresponding to all wheels in the vehicle can be equal. In some embodiments, the first adhesion coefficient limits corresponding to any two wheels in the vehicle can be unequal. The characteristic adhesion coefficient of each wheel can also be equal.

[0075] In some feasible embodiments of the present invention, after obtaining the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient, the processor can determine the first longitudinal acceleration of the whole vehicle at the current sampling time based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient.

[0076] S104. Based on the average wheel acceleration of each wheel, determine the longitudinal speed observation value of the whole vehicle at the current sampling time.

[0077] It is understandable that any wheel can correspond to an average wheel acceleration value in the current sampling period. In other words, the number of average wheel acceleration values ​​needed in the data processing of this embodiment is the same as the number of wheels.

[0078] In some feasible embodiments of the present invention, the processor can first obtain the average wheel acceleration from another processor. After obtaining the average wheel acceleration, the processor can determine the longitudinal speed observation value of the whole vehicle at the current sampling time based on the average wheel acceleration of each wheel.

[0079] S105. Based on the longitudinal speed observation, the estimated longitudinal speed change over 1 second, and the first longitudinal acceleration, determine the estimated longitudinal speed of the vehicle at the current sampling time.

[0080] It is understandable that the longitudinal vehicle speed observation value and the estimated value of the longitudinal vehicle speed change over 1 second can be calculated by another processor through an algorithm; or it can be calculated by the same processor that executes the algorithm for calculating the longitudinal vehicle speed estimate.

[0081] In some feasible embodiments of the present invention, after obtaining the longitudinal vehicle speed observation value, the longitudinal vehicle speed 1s change estimate value, and the first longitudinal acceleration, the processor can determine the longitudinal vehicle speed estimate value of the whole vehicle at the current sampling time based on the longitudinal vehicle speed observation value, the longitudinal vehicle speed 1s change estimate value, and the first longitudinal acceleration.

[0082] S106. Based on the longitudinal speed estimate and the lateral speed estimate, determine the lateral speed estimate of the whole vehicle at the current sampling time.

[0083] In some feasible embodiments of the present invention, after obtaining the longitudinal vehicle speed estimate, the processor can determine the lateral vehicle speed estimate of the whole vehicle at the current sampling time based on the longitudinal vehicle speed estimate and the lateral vehicle speed.

[0084] In summary, this embodiment can obtain the vehicle's mass, air resistance, front wheel steering angle, yaw rate, 1-second change in the second largest wheel speed, and lateral speed at the current sampling moment; the lateral force and longitudinal force of each wheel at the current sampling moment; the average wheel acceleration of each wheel during the current sampling period; the first characteristic adhesion coefficient and the limit of the first adhesion coefficient of each wheel at the previous sampling moment; the estimated 1-second change in the vehicle's longitudinal speed; and the estimated longitudinal speed of the entire vehicle. Based on air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, wheel lateral force, and second largest wheel speed... The longitudinal acceleration of the vehicle at the current sampling moment is determined by the 1-second change, yaw rate, and lateral speed. The first longitudinal acceleration of the vehicle at the current sampling moment is determined based on the longitudinal acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient. The observed longitudinal speed of the vehicle at the current sampling moment is determined based on the average wheel acceleration of each wheel. The estimated longitudinal speed of the vehicle at the current sampling moment is determined based on the observed longitudinal speed, the estimated 1-second change in longitudinal speed, and the first longitudinal acceleration. The estimated lateral speed of the vehicle at the current sampling moment is determined based on the estimated longitudinal speed and the lateral speed. This invention can improve the accuracy and real-time performance of speed calculation during autonomous driving through different algorithms.

[0085] Furthermore, the step of determining the longitudinal slope acceleration of the vehicle at the current sampling moment based on air resistance, vehicle mass, front wheel steering angle, longitudinal force of the first wheel, lateral force of the wheel, change in the second largest wheel speed in 1 second, yaw rate, and lateral vehicle speed may include, but is not limited to, steps S201-S202.

[0086] S201. Based on air resistance, vehicle mass, front wheel steering angle, longitudinal force of the first wheel, and lateral force of the wheel, determine the second longitudinal acceleration of the vehicle at the current sampling moment.

[0087] S202. Determine the longitudinal slope acceleration based on the second longitudinal acceleration, lateral vehicle speed, yaw rate, and the change in the second largest wheel speed over 1 second.

[0088] It is understandable that the second longitudinal acceleration is the longitudinal acceleration calculated through a calibration algorithm, rather than the longitudinal acceleration obtained by direct measurement, and the first wheel longitudinal force is the wheel longitudinal force calculated through a calibration algorithm.

[0089] In some feasible embodiments of the present invention, the processor can determine the first longitudinal acceleration of the vehicle based on air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, and wheel lateral force. After obtaining the second longitudinal acceleration, the processor can determine the longitudinal slope acceleration of the vehicle at the current sampling time based on the first longitudinal acceleration, lateral vehicle speed, yaw rate, and the change in the second largest wheel speed by 1 second.

[0090] Furthermore, the step of determining the second longitudinal acceleration based on air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, and wheel lateral force may include, but is not limited to, steps S211-S213.

[0091] S211. For any wheel, determine the longitudinal force of the second wheel based on the front wheel rotation angle, the longitudinal force of the first wheel, and the lateral force of the wheel.

[0092] S212. Sum the longitudinal forces of the second wheel for each wheel to obtain the longitudinal forces of the entire vehicle.

[0093] S213. Determine the second longitudinal acceleration based on the longitudinal force, air resistance, and vehicle mass.

[0094] It is understandable that the longitudinal force of the second wheel can be the superposition of the longitudinal force of the first wheel and the longitudinal component of the lateral force of the wheel.

[0095] In some feasible embodiments of the present invention, for the front wheels, the processor can determine the longitudinal component of the front wheel force based on the front wheel steering angle and the front wheel lateral force, and then add the longitudinal component of the front wheel force to the first wheel longitudinal force to obtain the second wheel longitudinal force. For the rear wheels, since the rear wheels have no steering angle, their longitudinal component of the force is 0, so the second wheel longitudinal force of the rear wheels is the same as the first wheel longitudinal force. After obtaining the second wheel longitudinal force of each wheel, the processor can sum the second wheel longitudinal forces of all wheels to obtain the longitudinal force of the entire vehicle. After obtaining the longitudinal force of the entire vehicle, the processor can obtain the forward force of the entire vehicle by combining it with air resistance. After obtaining the forward force of the entire vehicle, the processor can determine the final second longitudinal acceleration according to Newton's second law.

[0096] Furthermore, air resistance is obtained through steps S221 and S222:

[0097] S221. Obtain the longitudinal speed of the vehicle at the current sampling time.

[0098] S222. Determine the air resistance based on the longitudinal vehicle speed and the preset second calibration value.

[0099] In some feasible embodiments of the present invention, the longitudinal vehicle speed can be measured by a sensor. After obtaining the longitudinal vehicle speed, the processor can determine the air resistance of the entire vehicle using the longitudinal vehicle speed and a preset second calibration value. Specifically, after obtaining the longitudinal vehicle speed, the processor can input the longitudinal vehicle speed into formula (1) to obtain the air resistance of the entire vehicle:

[0100] F2 = T2 * (Vx) 2 (1)

[0101] In formula (1), F2 is the air resistance, T2 is the second calibration value, and Vx is the longitudinal vehicle speed.

[0102] Furthermore, the longitudinal force of the first wheel is obtained through steps S231 and S233:

[0103] S231. Obtain the wheel acceleration, wheel radius, wheel-end driving torque, and wheel-end braking torque at the current sampling moment.

[0104] S232. Determine the net torque at the wheel end based on the wheel end drive torque and the wheel end braking torque.

[0105] S233. Determine the longitudinal force of the first wheel based on the wheel acceleration, wheel radius, and net torque at the wheel end.

[0106] In some feasible embodiments of the present invention, the wheel acceleration, wheel radius, wheel-end driving torque, and wheel-end braking torque at the current sampling moment can all be obtained by corresponding sensors. After obtaining the wheel acceleration, wheel radius, wheel-end driving torque, and wheel-end braking torque at the current sampling moment, the processor can add the wheel-end driving torque and wheel-end braking torque to obtain the wheel-end net torque. After determining the wheel-end net torque, the wheel acceleration, wheel radius, wheel-end net torque, and the preset first calibration value are input into formula (2) for calculation, and the first wheel longitudinal force can be obtained. Formula (2) is as follows:

[0107] F1=L / R-ar*T1 (2)

[0108] In formula (2), F1 is the longitudinal force of the first wheel, L is the net torque at the wheel end, R is the wheel radius, ar is the wheel acceleration, and T1 is the first calibration value.

[0109] Furthermore, the step of determining the longitudinal slope acceleration based on the second longitudinal acceleration, lateral vehicle speed, yaw rate, and the change in the second largest wheel speed by 1 second may include, but is not limited to, step S241 or step S242.

[0110] When the vehicle is moving forward at the current sampling time, the second longitudinal acceleration, lateral speed, yaw rate, and the change in the second largest wheel speed over 1 second are input into formula (3) to obtain the longitudinal slope acceleration; formula (3) is:

[0111] V1=A-VM*VN-ax1 (3)

[0112] When the vehicle is not moving forward at the current sampling time, the second longitudinal acceleration, lateral vehicle speed, yaw rate, and the change in the second largest wheel speed over 1 second are input into formula (4) to obtain the longitudinal slope acceleration; the second formula (4) is:

[0113] V1=-A-VM*VN-ax1 (4)

[0114] In formulas (3) and (4), A is the change in the second largest wheel speed by 1 second, VM is the yaw rate of the whole vehicle, VN is the lateral speed of the whole vehicle, and ax1 is the second longitudinal acceleration.

[0115] For example, refer to Figure 3 The net torque at the wheel end is equal to the sum of the driving torque at the wheel end and the braking torque at the wheel end. Figure 3The longitudinal force 1 of the wheel, also known as the first wheel longitudinal force, is calculated as: Wheel end net torque / Wheel radius - Wheel acceleration * Calibration value 1. Air resistance is calculated as: Calibration value 2 * Estimated longitudinal speed^2. Transforming the longitudinal and lateral forces acting on each wheel into the vehicle's coordinate system yields the resultant longitudinal force of the entire vehicle. According to Newton's second law, dividing the resultant force by the vehicle's mass gives the second longitudinal acceleration ax1. If the vehicle is moving forward, the longitudinal acceleration is: Second largest wheel speed change in 1 second - Yaw rate * Lateral speed - Second longitudinal acceleration ax1; otherwise, the longitudinal acceleration is: - Second largest wheel speed change in 1 second - Yaw rate * Lateral speed - Second longitudinal acceleration ax1. After obtaining the longitudinal acceleration, a smoothing correction can be applied to obtain the final longitudinal acceleration.

[0116] Furthermore, referring to Figure 4 as well as Figure 5 The step of determining the first longitudinal acceleration of the vehicle at the current sampling time based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient includes, but is not limited to, steps S301 to S304.

[0117] S301. Based on the first adhesion coefficient limit and the longitudinal slope acceleration, determine the second adhesion coefficient limit for each wheel at the current sampling time.

[0118] S302. Determine the second characteristic adhesion coefficient of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit.

[0119] S303. Based on the second characteristic adhesion coefficient, determine the second wheel longitudinal force of each wheel at the current sampling time.

[0120] S304. Based on the longitudinal force of the second wheel, determine the first longitudinal acceleration of the whole vehicle at the current sampling moment.

[0121] It is understandable that the second adhesion coefficient limit is the adjusted adhesion coefficient limit for each wheel at the current sampling time; the second adhesion coefficient limit for each wheel can be the same or different. The first adhesion coefficient limit can be the adhesion coefficient limit for each wheel at the previous sampling time; the longitudinal slope acceleration can be the longitudinal slope acceleration of the entire vehicle at the current sampling time. The second characteristic adhesion coefficient is the adjusted characteristic adhesion coefficient for each wheel at the current sampling time. The second wheel longitudinal force can be the wheel longitudinal force calculated at the current sampling time. The first longitudinal acceleration is the longitudinal acceleration determined by parameters such as the adhesion coefficient and the longitudinal slope acceleration.

[0122] In some feasible embodiments of the present invention, the processor can determine the second adhesion coefficient limit for each wheel based on the first adhesion coefficient limit and the longitudinal slope acceleration. After obtaining the second adhesion coefficient limit, the processor can determine the second characteristic adhesion coefficient of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit. After obtaining the second characteristic adhesion coefficient, the processor can determine the second longitudinal force of each wheel at the current sampling time based on the second characteristic adhesion coefficient. After determining the second longitudinal force of each wheel at the current sampling time, the processor can determine the first longitudinal acceleration of the entire vehicle at the current sampling time based on the second longitudinal force. Specifically, after obtaining the second characteristic adhesion coefficient, for any wheel, the processor can use the product of the wheel vertical force of the corresponding wheel and the second characteristic adhesion coefficient as the second longitudinal force of the wheel. After obtaining several second longitudinal forces corresponding to all wheels, the processor determines the longitudinal component of the wheel lateral force of the front wheel based on the front wheel steering angle and the corresponding wheel lateral force of the front wheel, and uses the sum of the second longitudinal force of each wheel and the longitudinal component of the wheel lateral force of the front wheel as the longitudinal resultant force of the entire vehicle. The difference between the longitudinal force and the air resistance of the entire vehicle is taken as the resultant force of the entire vehicle. Given the resultant force and mass of the entire vehicle, the first longitudinal acceleration of the vehicle at the current sampling moment can be obtained according to Newton's second law.

[0123] Furthermore, referring to Figure 4 The step of determining the second adhesion coefficient limit for each wheel at the current sampling time based on the first adhesion coefficient limit and the longitudinal slope acceleration may include, but is not limited to, steps S311 to S312.

[0124] S311. Determine the adhesion coefficient offset of each wheel at the current sampling moment based on the longitudinal slope acceleration.

[0125] S312. Determine the second adhesion coefficient limit based on the adhesion coefficient bias and the first adhesion coefficient limit.

[0126] In some feasible embodiments of the present invention, the processor can determine the adhesion coefficient bias based on the longitudinal slope acceleration. After obtaining the adhesion coefficient bias, the processor can determine the second adhesion coefficient limit for each wheel at the current sampling time based on the adhesion coefficient bias and the first adhesion coefficient limit.

[0127] Furthermore, referring to Figure 4 The step of determining the adhesion coefficient bias of each wheel at the current sampling time based on the longitudinal slope acceleration may include, but is not limited to, steps S321 and S322.

[0128] S321. Determine the slope offset based on the vehicle speed and longitudinal slope acceleration at the current sampling time.

[0129] S322. Determine the adhesion coefficient offset based on the lateral dynamic offset, slope offset, and preset base offset at the current sampling time.

[0130] In some feasible embodiments of the present invention, the processor can obtain the lateral dynamic bias at the current sampling time by using the front axle lateral force measured by the sensor at the current sampling moment, and the corresponding mapping table including lateral dynamic bias and front axle lateral force. The processor can obtain the slope bias at the current sampling moment by using the longitudinal acceleration and the measured longitudinal speed of the vehicle, and the corresponding mapping table including slope bias, longitudinal speed, and slope acceleration. Based on the slope bias, lateral dynamic bias, and a preset base bias, the processor can determine the adhesion coefficient bias at the current sampling moment.

[0131] Furthermore, referring to Figure 4 The step of determining the second characteristic adhesion coefficient of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit may include, but is not limited to, steps S331 to S334.

[0132] S331. Based on the first characteristic adhesion coefficient and the vertical force of each wheel at the current sampling time, determine the change in wheel acceleration of each wheel in 1s at the current sampling time.

[0133] S332. Based on the wheel acceleration change over 1 second, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius, determine the predicted wheel acceleration value and the corrected wheel acceleration value for each wheel at the current sampling time.

[0134] S333. Based on the predicted wheel acceleration value and the corrected wheel acceleration value, determine the slip ratio of each wheel at the current sampling moment.

[0135] S334. Determine the second characteristic adhesion coefficient based on the slip ratio and the second adhesion coefficient limit.

[0136] Understandably, the vertical force on each wheel can be the vertical force at the current sampling moment, which can be measured by sensors. The change in wheel acceleration over 1 second can be the change in wheel acceleration over one second at the previous sampling moment. The wheel acceleration, wheel speed, and wheel radius at the previous sampling moment can be measured by sensors.

[0137] In some feasible embodiments of the present invention, the processor can acquire the vertical force of each wheel at the current sampling moment through a sensor. After obtaining the vertical force, the processor can determine the 1-second change in wheel acceleration of each wheel at the current sampling moment based on the first characteristic adhesion coefficient of the previous sampling moment and the vertical force of the wheel at the current sampling moment. After obtaining the 1-second change in wheel acceleration, the processor can determine the predicted value and the corrected value of wheel acceleration at the current sampling moment based on the 1-second change in wheel acceleration, the wheel acceleration of the previous sampling moment, the wheel speed at the current sampling moment, and the wheel radius. Then, the processor can determine the slip ratio of each wheel at the current sampling moment based on the predicted value and the corrected value of wheel acceleration. Finally, the processor can determine the second characteristic adhesion coefficient at the current sampling moment based on the slip ratio and the second adhesion coefficient limit at the current sampling moment.

[0138] Furthermore, referring to Figure 4 The step of determining the change in wheel acceleration 1s for each wheel based on the first characteristic adhesion coefficient and the vertical force of the wheel may include, but is not limited to, steps S341 to S342.

[0139] S341. Based on the first characteristic adhesion coefficient and the wheel vertical force, determine the longitudinal force of each wheel at the current sampling moment.

[0140] S342. Based on the longitudinal force of the wheel, the wheel radius of each wheel, the net wheel torque of each wheel at the current sampling time, and the wheel moment of inertia of each wheel at the current sampling time, determine the change in wheel acceleration over 1 second.

[0141] It is understandable that the longitudinal force of the wheel can be the longitudinal force of the wheel at the current sampling moment, and the net torque and moment of inertia of the wheel can be the net torque and moment of inertia of the wheel at the current sampling moment.

[0142] In some feasible embodiments of the present invention, the processor can determine the longitudinal force of the wheel based on the first characteristic adhesion coefficient and the vertical force of the wheel. Then, the processor can determine the change in wheel acceleration per second based on the longitudinal force of the wheel, the wheel radius, the net torque of the wheel, and the moment of inertia of the wheel. Specifically, the processor can use the product of the first characteristic adhesion coefficient and the vertical force of the wheel as the longitudinal force of the wheel. After obtaining the longitudinal force of the wheel, the processor can input the longitudinal force of the wheel, the wheel radius, the net torque of the wheel, and the moment of inertia of the wheel into formula (5) to obtain the change in wheel acceleration per second. Formula (5) is:

[0143] At=(L1-R*Ft) / w (5)

[0144] In formula (5), At is the change in wheel acceleration over 1 second, L1 is the net torque of the wheel, R is the wheel radius, w is the wheel moment of inertia, and Ft is the longitudinal force of the wheel.

[0145] Furthermore, referring to Figure 4 The step of determining the predicted wheel acceleration value and the corrected wheel acceleration value for each wheel at the current sampling time based on the wheel acceleration change over 1 second, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius may include, but is not limited to, steps S351 and S352.

[0146] S351. Determine the predicted value of wheel acceleration based on the 1s change in wheel acceleration and the wheel acceleration itself.

[0147] S352. Determine the wheel acceleration correction value based on the predicted wheel acceleration value, wheel speed, and wheel radius.

[0148] In some feasible embodiments of the present invention, reference is made to Figure 4 The processor can determine the predicted wheel acceleration value based on the 1-second change in wheel acceleration and the wheel acceleration at the previous sampling time. Then, the processor can determine the corrected wheel acceleration value based on the predicted wheel acceleration value, wheel speed, and wheel radius.

[0149] Furthermore, referring to Figure 4 The step of determining the slip ratio of each wheel at the current sampling moment based on the predicted wheel acceleration value and the corrected wheel acceleration value may include, but is not limited to, steps S361 to S363.

[0150] S361. Based on the predicted wheel acceleration value and the corrected wheel acceleration value, determine the wheel acceleration of each wheel at the current sampling moment.

[0151] S362. Based on the wheel acceleration, determine the calculated wheel speed of each wheel at the current sampling moment.

[0152] S363. Based on the calculated wheel speed and longitudinal vehicle speed, determine the slip ratio of each wheel at the current sampling moment.

[0153] In some feasible embodiments of the present invention, the processor can determine the wheel acceleration of each wheel at the current sampling moment based on the predicted wheel acceleration value and the corrected wheel acceleration value. Then, based on the wheel acceleration, the calculated wheel speed of each wheel at the current sampling moment is determined. Finally, based on the calculated wheel speed and the longitudinal vehicle speed of the wheel, the slip ratio of each wheel at the current sampling moment is determined. Specifically, for any wheel, by inputting the predicted wheel acceleration value, the corrected wheel acceleration value, and the preset sixth calibration value into formula (6), the wheel acceleration of each wheel at the current sampling moment can be obtained. Formula (6) is:

[0154] As=Ap+Aq*T6 (6)

[0155] In formula (6), As is the wheel acceleration, Ap is the predicted wheel acceleration, Aq is the corrected wheel acceleration, and T6 is the preset sixth calibration value. After obtaining the wheel acceleration of each wheel, for any given wheel, the product of the wheel acceleration and the wheel radius is used as the calculated wheel speed. For any given wheel, the ratio of the calculated wheel speed to the longitudinal vehicle speed is used as the wheel slip ratio at the current sampling time.

[0156] Furthermore, referring to Figure 4 The step of determining the second characteristic adhesion coefficient based on the slip ratio and the second adhesion coefficient limit may include, but is not limited to, steps S371 and S372, or steps S371 and S373.

[0157] S371. Determine the theoretical coefficient of the second characteristic adhesion based on the slip ratio and tire stiffness.

[0158] S372. When the theoretical coefficient of the second characteristic adhesion is less than or equal to the limit of the second adhesion coefficient, the theoretical coefficient of the second characteristic adhesion shall be used as the second characteristic adhesion coefficient.

[0159] S373. When the theoretical coefficient of the second characteristic adhesion is greater than the limit of the second adhesion coefficient, the limit of the second adhesion coefficient shall be used as the second characteristic adhesion coefficient.

[0160] In some feasible embodiments of the present invention, the processor can determine the second characteristic adhesion theoretical coefficient based on the slip ratio and tire stiffness. After obtaining the second characteristic adhesion theoretical coefficient, if the second characteristic adhesion theoretical coefficient is less than or equal to the second adhesion coefficient limit, the processor can use the second characteristic adhesion theoretical coefficient as the second characteristic adhesion coefficient. If the second characteristic adhesion theoretical coefficient is greater than the second adhesion coefficient limit, the processor can use the second adhesion coefficient limit as the second characteristic adhesion coefficient.

[0161] It should be noted that the wheel acceleration of each wheel at the previous sampling moment mentioned in step S351 can be calculated using the same calculation logic as steps S351, S352, S361, S362, S363, S371, S372 and S373, or it can be directly measured by testing.

[0162] Furthermore, referring to Figure 6 as well as Figure 7 The step of determining the longitudinal speed observation value of the whole vehicle at the current sampling time based on the average wheel acceleration of each wheel may include, but is not limited to, steps S401 to S407.

[0163] S401. For any wheel, based on the mean wheel acceleration and the first wheel acceleration corresponding to several sampling moments in the current sampling period, determine the cumulative value of wheel acceleration variance and the wheel acceleration corresponding to several sampling moments in the current sampling period.

[0164] S402. Based on the wheel jerk, determine the mean value of the wheel jerk and the cumulative value of the wheel jerk variance.

[0165] S403. Determine the reliability of the wheel acceleration for each wheel based on the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration.

[0166] S404. Determine the reliability of the wheel jerk for each wheel based on the wheel jerk, the mean wheel jerk, and the cumulative variance of the wheel jerk.

[0167] S405. Determine the wheel speed reliability of each wheel based on the reliability of wheel acceleration, wheel acceleration, wheel vertical force, wheel speed and longitudinal vehicle speed difference, and wheel acceleration and vehicle acceleration difference.

[0168] S406. When the vehicle is not in a counter-steering state and is not in a handbrake state, determine the vehicle speed observation value at the current sampling time based on the wheel speed confidence of each wheel and the wheel speed of each wheel at the current sampling time.

[0169] S407. Based on the observed vehicle speed, the upper limit of vehicle speed, and the lower limit of vehicle speed, determine the longitudinal speed observed value of the whole vehicle at the current sampling time.

[0170] It is understandable that the cumulative variance of wheel acceleration can be the sum of the squared differences between the wheel acceleration and the mean wheel acceleration at all sampling moments in the current sampling period. For example, the 10 sampling moments include ten wheel accelerations, X1-X10. X11 is the mean wheel acceleration, and the cumulative variance of wheel acceleration is (X1-X11). 2 +(X2-X11) 2 +(X3-X11) 2 +....+(X10-X11) 2 Similarly, the cumulative variance of wheel jerkers over 10 sampling times includes ten wheel jerkers from Y1 to Y10. Y11 is the mean of the wheel jerkers, and the cumulative variance of wheel jerkers is (Y1 - Y11). 2 +(Y2-Y11) 2 +(Y3-Y11) 2 +....+(Y10-Y11) 2 .

[0171] In some feasible embodiments of the present invention, the wheel acceleration can be obtained by differentiating the first wheel acceleration with the wheel acceleration at the previous sampling moment, and the cumulative variance of wheel acceleration can be calculated by the first wheel acceleration and the mean wheel acceleration corresponding to one sampling moment of the current sampling period for the current wheel. The mean wheel acceleration can be the average of the wheel accelerations corresponding to several sampling moments in the current sampling period. After obtaining the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration, the processor can determine the reliability of the wheel acceleration for each wheel using the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration. After obtaining the wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration, the processor can determine the reliability of the wheel acceleration based on the wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration. After obtaining the wheel acceleration confidence level and the wheel acceleration confidence level, the processor can determine the wheel speed confidence level of each wheel through five confidence levels: wheel acceleration confidence level, wheel acceleration confidence level, wheel vertical force confidence level, wheel speed and longitudinal vehicle speed difference confidence level, and wheel acceleration and vehicle acceleration difference confidence level.

[0172] Understandably, the reliability of the wheel vertical force can be obtained by looking up the wheel vertical force of each wheel in a table, the reliability of the difference between wheel speed and longitudinal vehicle speed can be obtained by looking up the difference between wheel speed and longitudinal vehicle speed of each wheel in a table, and the reliability of the difference between wheel acceleration and vehicle acceleration can be obtained by looking up the difference between wheel acceleration and vehicle acceleration of each wheel in a table.

[0173] Furthermore, the step of determining the wheel speed reliability of each wheel based on the reliability of wheel acceleration, wheel acceleration jerk, wheel vertical force, wheel speed and longitudinal vehicle speed difference, and wheel acceleration and vehicle acceleration difference can specifically include:

[0174] For any given wheel, the minimum reliability among wheel acceleration reliability, wheel acceleration reliability, wheel vertical force reliability, wheel speed and longitudinal vehicle speed difference reliability, and wheel acceleration and vehicle acceleration difference reliability is taken as the wheel speed reliability of the corresponding wheel.

[0175] For example, for any wheel, let the wheel acceleration confidence level be c, the wheel acceleration confidence level be d, the wheel vertical force confidence level be e, the wheel speed and longitudinal vehicle speed difference confidence level be f, and the wheel acceleration and vehicle acceleration difference confidence level be g, where e < d < c < f < g. Then the wheel speed confidence level for any wheel is e. It can be understood that the wheel speed confidence levels for other wheels can be calculated in the same way.

[0176] Furthermore, referring to Figure 7The step of determining the reliability of the wheel acceleration of each wheel based on the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of wheel acceleration may include, but is not limited to, steps S411 to S413.

[0177] S411. Determine the first confidence level based on the first wheel acceleration and the average wheel acceleration.

[0178] S412. Determine the second confidence level based on the cumulative value of the wheel acceleration variance.

[0179] S413. The lower of the first and second confidence levels is taken as the confidence level of the wheel acceleration.

[0180] In some feasible embodiments of the present invention, the processor can calculate a difference between the first wheel acceleration and the mean wheel acceleration, and then determine a first confidence level by looking up the difference in a table; simultaneously, the processor can determine a second confidence level by looking up the cumulative variance of the wheel acceleration in a table. Finally, the smaller of the first confidence level and the second confidence level is taken as the wheel acceleration confidence level.

[0181] Furthermore, referring to Figure 7 The step of determining the longitudinal speed observation of the whole vehicle at the current sampling time based on the observed speed, the upper limit of the speed, and the lower limit of the speed can include any one of steps S421, S422, or S423.

[0182] S421. When the observed vehicle speed is greater than the lower limit of the vehicle speed and less than the upper limit of the vehicle speed, the observed vehicle speed shall be used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time.

[0183] S422. When the observed vehicle speed is less than or equal to the lower limit of vehicle speed, the lower limit of vehicle speed shall be used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time.

[0184] S423. When the observed vehicle speed is greater than or equal to the upper limit of vehicle speed, the upper limit of vehicle speed shall be used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time.

[0185] In some feasible embodiments of the present invention, the upper limit of vehicle speed can be determined by the longitudinal acceleration of the vehicle measured by the sensor and whether the vehicle is in a starting state. When the vehicle is in a starting state, the upper limit of vehicle speed can be obtained by looking up a table. When the vehicle is not in a starting state and the longitudinal acceleration of the vehicle measured by the sensor is greater than a preset value, the upper limit of vehicle speed is 100 m / s. When the longitudinal acceleration of the vehicle measured by the sensor is less than or equal to the preset value and the lateral speed is less than a preset threshold, and the vehicle is on a non-rough road, the upper limit of vehicle speed is the minimum wheel speed among all wheels. When the longitudinal acceleration of the vehicle measured by the sensor is less than or equal to the preset value and the lateral speed is less than a preset threshold, and the vehicle is not on a non-rough road, the upper limit of vehicle speed is the second minimum wheel speed among all wheels.

[0186] The lower speed limit can be determined by several parameters: minimum wheel speed, overall vehicle speed, longitudinal speed change per second (LTV), and the LTV of all four wheel speeds. Specifically, the threshold is obtained by looking up the difference between the minimum wheel speed and the overall vehicle speed in a table. The difference in LTV is equal to the difference between the longitudinal speed change per second and the average LTV change of all four wheel speeds. The timer's count can vary with this difference. When the timer's count is greater than the threshold, the lower speed limit equals the average speed of all four wheels. When the timer's count is greater than the threshold, the lower speed limit is 0. When the lateral speed is low, the lower speed limit is the second highest wheel speed among all wheel speeds.

[0187] Furthermore, referring to Figure 7 The step of determining the estimated longitudinal speed of the whole vehicle at the current sampling time based on the longitudinal speed observation, the estimated longitudinal speed change over 1 second, and the first longitudinal acceleration may include, but is not limited to, steps S431 and S432.

[0188] S431. Based on the first longitudinal acceleration, determine the observed value of the longitudinal vehicle speed change over 1 second at the current sampling time.

[0189] S432. When the current sampling time is the i-th time, the estimated longitudinal speed of the whole vehicle at the current sampling time is obtained by formula (7):

[0190] VI i =VI i-1 +k 21 *(VJ-VM i-1 )+k 22 *(VK-VI i-1 (7)

[0191] In formula (7), VI i VM represents the estimated longitudinal speed of the vehicle at the current sampling time. i-1 VI is the estimated value of the longitudinal vehicle speed change over 1 second. i-1The estimated longitudinal vehicle speed at the previous sampling time. VJ is the observed change in longitudinal vehicle speed over 1 second, and VK is the observed longitudinal vehicle speed. k 21 k is the first calibration coefficient at the current sampling time. 22 is the second calibration coefficient at the current sampling time, i > 1.

[0192] In some feasible embodiments of the present invention, the first calibration coefficient and the second calibration coefficient at the current sampling time can be determined by a first set of formulas. The first set of formulas includes:

[0193] m 11 =p 11 (k-1)+T7

[0194] m 12 =p 11 (k-1)*t+p 12 (k-1)+T8

[0195] m 21 =p 11 (k-1)*t+p 21 (k-1)

[0196] m 22 =p 21 (k-1)*t+p 12 (k-1)*t+p 22 (k-1)

[0197] m d =m 11 *m 22 +m 11 *T10+T9*m 22 +T9*T10-m 12 *m 21

[0198] k11=(m 11 *m 22 +m 11 *T10-m 12 *m 21 ) / m d

[0199] k12=(m 12 *T9) / m d

[0200] k 21 =(m 21 *T 10 ) / m d

[0201] k 22 =-m 21 *m12 +m 22 *m 11 +m 22 *T9

[0202] In the first set of formulas, m 11 The initial value is T11, m 12 The initial value is T12, m 21 The initial value is T13, m 22 The initial value is T14. T7-T14 are all preset values. After calculating the estimated longitudinal vehicle speed at the current sampling time, p... 11 (k-1), p 12 (k-1), p 13 (k-1), p 14 (k-1) are updated to p respectively. 11 (k), p 12 (k), p 13 (k) and p 14 (k). Where p 11 (k), p 12 (k), p 13 (k) and p 14 (k) is calculated from the second set of formulas, which are:

[0203] p 11 (k)=m 11 -k 11 *m 11 -k 12 *m 21

[0204] p 12 (k)=m 12 -k 11 *m 12 -k 12 *m 22

[0205] p 13 (k)=m 21 -k 21 *m 11 -k 22 *m 21

[0206] p 14 (k)=m 22 -k 21 *m 12 -k 22 *m 22

[0207] Furthermore, referring to Figure 7The step of determining the longitudinal vehicle speed change 1s observation value at the current sampling time based on the first longitudinal acceleration may include, but is not limited to, step S441 or step S442.

[0208] S441. When the vehicle is moving forward at the current sampling time, the observed value of the longitudinal speed change over 1 second satisfies formula (8):

[0209] VJ=ax2+VM*VN (8)

[0210] S442. When the vehicle is not moving forward at the current sampling time, the observed value of the longitudinal speed change over 1 second satisfies formula (9):

[0211] VJ = ax² - VM * VN (9)

[0212] In formulas (8) and (9), VJ is the observed value of the longitudinal vehicle speed change over 1 second, ax2 is the first longitudinal acceleration of the vehicle at the current sampling time, VM is the yaw rate of the vehicle at the current sampling time, and VN is the lateral vehicle speed of the vehicle at the current sampling time.

[0213] Furthermore, referring to Figure 8 The step of determining the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and lateral speed of the vehicle at the current sampling time may include, but is not limited to, steps S501 to S505.

[0214] S501. Based on the estimated longitudinal speed and lateral speed of the vehicle at the current sampling time, determine the longitudinal slip ratio of each wheel and the second wheel lateral force of each wheel at the current sampling time.

[0215] S502. Based on the longitudinal slip ratio, determine the second wheel longitudinal force of each wheel at the current sampling time.

[0216] S503. Determine the lateral acceleration of the vehicle at the current sampling time based on the vehicle mass, front wheel angle, longitudinal force of the second wheel, and lateral force of the second wheel of each wheel at the current sampling time.

[0217] S504. Based on the estimated lateral acceleration, longitudinal speed, and yaw rate, determine the lateral speed change of the vehicle in 1 second at the current sampling time.

[0218] S505. Based on the lateral speed change over 1 second, determine the estimated lateral speed of the vehicle at the current sampling time.

[0219] In some feasible embodiments of the present invention, reference is made to Figure 9The processor can calculate the longitudinal wheel speeds of the four wheels based on the estimated longitudinal vehicle speed and the front wheel steering angle. Based on these longitudinal wheel speeds and the estimated longitudinal vehicle speeds, it determines the longitudinal slip ratio of each wheel. Simultaneously, the processor can determine the wheel yaw angle based on the estimated longitudinal and lateral vehicle speeds. After obtaining the wheel yaw angle and longitudinal slip ratio, the processor can calculate the third longitudinal force of each wheel at the current sampling moment using the longitudinal slip ratio and the vertical force of each wheel. Simultaneously, it determines the lateral adhesion coefficient using the wheel yaw angle and a preset third calibration value. After obtaining the lateral adhesion coefficient, the processor can determine the second wheel lateral force based on the lateral adhesion coefficient and the vertical force of each wheel. Then, the processor can determine the lateral component force of the front wheels based on the front wheel steering angle and the third wheel longitudinal force. Then, the processor can determine the total lateral force of the entire vehicle based on the lateral component force and the second wheel lateral force. Finally, the processor can determine the calculated lateral acceleration of the entire vehicle at the current sampling moment based on the total lateral force, the vehicle mass, and Newton's second law. Finally, based on the calculated lateral acceleration, longitudinal vehicle speed, and yaw angle, the lateral speed change over 1 second is determined, and the lateral speed change over 1 second at the current sampling time is integrated in the time domain to obtain the estimated lateral speed of the vehicle at the current sampling time.

[0220] In addition, refer to Figure 10 ,and Figure 1Corresponding to the method described above, embodiments of the present invention also provide a vehicle speed determination device for a vehicle control system. This device may include a first processing unit 1001, a second processing unit 1002, a third processing unit 1003, a fourth processing unit 1004, a fifth processing unit 1005, and a sixth processing unit 1006. The first processing unit 1001 can be used to acquire the following data: vehicle mass, air resistance, front wheel steering angle, yaw rate, second-largest wheel speed change over 1 second, and lateral speed at the current sampling time; wheel lateral force and first wheel longitudinal force at the current sampling time; average wheel acceleration of each wheel during the current sampling period; first characteristic adhesion coefficient and first adhesion coefficient limit of each wheel at the previous sampling time; estimated longitudinal speed change over 1 second at the previous sampling time; and estimated longitudinal speed of the vehicle at the previous sampling time. The second processing unit 1002 can be used to determine the longitudinal acceleration of the vehicle at the current sampling time based on air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, wheel lateral force, second largest wheel speed change over 1 second, yaw rate, and lateral vehicle speed. The third processing unit 1003 can be used to determine the first longitudinal acceleration of the vehicle at the current sampling time based on the longitudinal acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient. The fourth processing unit 1004 can be used to determine the observed longitudinal vehicle speed at the current sampling time based on the average wheel acceleration of each wheel. The fifth processing unit 1005 can be used to determine the estimated longitudinal vehicle speed at the current sampling time based on the observed longitudinal vehicle speed, the estimated longitudinal speed change over 1 second, and the first longitudinal acceleration. The sixth processing unit 1006 can be used to determine the estimated lateral vehicle speed at the current sampling time based on the estimated longitudinal vehicle speed and the lateral vehicle speed.

[0221] It should be noted that the acquisition unit can be any integrated circuit unit or microprocessor unit obtained by integrating a chip with processing functions and its peripheral circuits using existing integration technology. Similarly, the first processing unit and the second processing unit can also be any integrated circuit module or microprocessor module obtained by integrating a chip with processing functions and its peripheral circuits using existing integration technology. Furthermore, the first processing unit and the second processing unit may include one or more memories. These memories can be used to store the specific algorithm for determining vehicle speed in the vehicle control system of this invention, and the "1s" mentioned in this invention refers to one second.

[0222] In some embodiments of the present invention, the specific device connection methods and device settings between the first processing unit 1001 and the second processing unit 1002, the second processing unit 1002 and the third processing unit 1003, the third processing unit 1003 and the fourth processing unit 1004, the fourth processing unit 1004 and the fifth processing unit 1005, and the fifth processing unit 1005 and the sixth processing unit 1006 are not limited.

[0223] It should be noted that the content of the above-described vehicle control system speed determination method embodiments is applicable to the vehicle control system speed determination device embodiments. The specific functions implemented by the vehicle control system speed determination device embodiments are the same as those of the above-described vehicle control system speed determination method embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described vehicle control system speed determination method embodiments.

[0224] and Figure 1 Corresponding to the method, this embodiment of the invention also provides a vehicle speed determination device for a vehicle control system, the specific structure of which can be referred to Figure 11 ,include:

[0225] At least one processor 1011;

[0226] At least one memory 1012 is used to store at least one program;

[0227] When at least one program is executed by at least one processor, a method for determining vehicle speed in a vehicle control system is implemented by at least one processor.

[0228] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0229] and Figure 1 Corresponding to the method described above, embodiments of the present invention also provide a computer-readable storage medium storing processor-executable instructions, which, when executed by a processor, are used to perform a vehicle speed determination method for a vehicle control system.

[0230] The contents of the above-described vehicle control system speed determination method embodiments are all applicable to this storage medium embodiment. The specific functions implemented by this storage medium embodiment are the same as those of the above-described vehicle control system speed determination method embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described vehicle control system speed determination method embodiments.

[0231] Furthermore, the present invention also provides a vehicle, which may include a vehicle speed determination device or a vehicle speed determination apparatus for a front-mounted vehicle control system. Specifically, the vehicle may be a private car, such as a sedan, SUV, MPV, or pickup truck. The vehicle may also be a commercial vehicle, such as a van, bus, small truck, or large semi-trailer. The vehicle may be a gasoline-powered vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it may be a hybrid vehicle or a pure electric vehicle.

[0232] The contents of the above-described vehicle control system speed determination device or system embodiments are all applicable to this vehicle embodiment. The specific functions implemented in this vehicle embodiment are the same as those of the above-described vehicle control system speed determination device or system embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described vehicle control system speed determination device or system embodiments.

[0233] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0234] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0235] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0236] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable programs for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can retrieve and execute a program from or in conjunction with such a program execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with a program execution system, apparatus, or device.

[0237] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0238] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable program execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0239] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0240] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0241] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A method for determining vehicle speed in a vehicle control system, characterized in that, Includes the following steps: The system acquires the following data: vehicle mass, air resistance, front wheel steering angle, yaw rate, second largest wheel speed change over 1 second, and lateral speed at the current sampling time; wheel lateral force and first wheel longitudinal force at the current sampling time; mean wheel acceleration of each wheel during the current sampling period; first characteristic adhesion coefficient and first adhesion coefficient limit of each wheel at the previous sampling time; estimated longitudinal speed change over 1 second and estimated longitudinal speed of the vehicle at the previous sampling time. Based on the air resistance, the vehicle mass, the front wheel steering angle, the longitudinal force of the first wheel, the lateral force of the wheel, the 1s change of the second largest wheel speed, the yaw rate, and the lateral vehicle speed, determine the longitudinal slope acceleration of the vehicle at the current sampling time. Based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient, the first longitudinal acceleration of the vehicle at the current sampling time is determined; Based on the average wheel acceleration of each wheel, determine the longitudinal speed observation value of the whole vehicle at the current sampling time; Based on the longitudinal vehicle speed observation value, the estimated value of the longitudinal vehicle speed change over 1 second, and the first longitudinal acceleration, the estimated value of the longitudinal vehicle speed of the whole vehicle at the current sampling time is determined. Based on the estimated longitudinal speed and the estimated lateral speed of the vehicle at the current sampling time, the estimated lateral speed of the vehicle at the current sampling time is determined.

2. The vehicle speed determination method for a vehicle control system according to claim 1, characterized in that, The determination of the vehicle's longitudinal acceleration at the current sampling moment based on the air resistance, vehicle mass, front wheel steering angle, first wheel longitudinal force, wheel lateral force, second largest wheel speed change over 1 second, yaw rate, and lateral vehicle speed includes: The second longitudinal acceleration of the vehicle at the current sampling moment is determined based on the air resistance, the vehicle mass, the front wheel steering angle, the longitudinal force of the first wheel, and the lateral force of the wheel. The longitudinal slope acceleration is determined based on the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the change in the second largest wheel speed by 1 second.

3. The vehicle speed determination method for a vehicle control system according to claim 2, characterized in that, The step of determining the second longitudinal acceleration of the vehicle at the current sampling moment based on the air resistance, the vehicle mass, the front wheel steering angle, the first wheel longitudinal force, and the wheel lateral force includes: For any given wheel, the longitudinal force of the second wheel is determined based on the front wheel steering angle, the longitudinal force of the first wheel, and the lateral force of the wheel. The longitudinal force of the second wheel for each wheel is summed to obtain the longitudinal force of the entire vehicle at the current sampling time; The second longitudinal acceleration of the vehicle is determined based on the longitudinal force of the vehicle, the air resistance, and the mass of the vehicle.

4. The vehicle speed determination method for a vehicle control system according to claim 3, characterized in that, The air resistance is obtained through the following steps: Obtain the longitudinal speed of the vehicle at the current sampling time; The air resistance is determined based on the longitudinal vehicle speed and a preset second calibration value.

5. The vehicle speed determination method for a vehicle control system according to claim 3, characterized in that, The longitudinal force of the first wheel is obtained through the following steps: Obtain the wheel acceleration, wheel radius, wheel-end driving torque, and wheel-end braking torque at the current sampling moment; The wheel-end net torque is determined based on the wheel-end drive torque and wheel-end braking torque. The longitudinal force of the first wheel is determined based on the wheel acceleration, the wheel radius, and the net torque at the wheel end.

6. The vehicle speed determination method for a vehicle control system according to claim 2, characterized in that, The step of determining the longitudinal slope acceleration based on the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed includes: When the vehicle is moving forward at the current sampling moment, the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed are input into the first formula to obtain the longitudinal slope acceleration; the first formula is: V1 = A - VM * VN - ax1, When the vehicle is not moving forward at the current sampling time, the second longitudinal acceleration, the lateral vehicle speed, the yaw rate, and the 1-second change in the second largest wheel speed are input into the second formula to obtain the longitudinal slope acceleration; the second formula is: V1 = -A - VM * VN - ax1, In the first formula and the second formula, A is the second largest wheel speed change in 1s, VM is the yaw rate of the whole vehicle, VN is the lateral speed of the whole vehicle, and ax1 is the second longitudinal acceleration.

7. The vehicle speed determination method for a vehicle control system according to claim 1, characterized in that, The step of determining the first longitudinal acceleration of the vehicle at the current sampling moment based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient includes: Based on the first adhesion coefficient limit and the longitudinal slope acceleration, determine the second adhesion coefficient limit for each wheel at the current sampling time; Based on the first characteristic adhesion coefficient and the second adhesion coefficient limit, determine the second characteristic adhesion coefficient of each wheel at the current sampling time; Based on the second characteristic adhesion coefficient, determine the fourth wheel longitudinal force of each wheel at the current sampling time; Based on the longitudinal force of the fourth wheel, the first longitudinal acceleration of the vehicle at the current sampling moment is determined.

8. The vehicle speed determination method for a vehicle control system according to claim 7, characterized in that, The step of determining the second adhesion coefficient limit for each wheel at the current sampling time based on the first adhesion coefficient limit and the longitudinal slope acceleration includes: Based on the longitudinal slope acceleration, determine the adhesion coefficient bias of each wheel at the current sampling moment; The second adhesion coefficient limit is determined based on the adhesion coefficient bias and the first adhesion coefficient limit.

9. The vehicle speed determination method for a vehicle control system according to claim 8, characterized in that, The step of determining the adhesion coefficient bias of each wheel at the current sampling moment based on the longitudinal slope acceleration includes: The slope offset is determined based on the vehicle speed at the current sampling time and the longitudinal slope acceleration. The adhesion coefficient offset is determined based on the lateral dynamic offset at the current sampling time, the slope offset, and the preset base offset.

10. The vehicle speed determination method for a vehicle control system according to claim 7, characterized in that, The step of determining the second characteristic adhesion coefficient of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the second adhesion coefficient limit includes: Based on the first characteristic adhesion coefficient and the vertical force of each wheel at the current sampling time, determine the change in wheel acceleration of each wheel in 1 second at the current sampling time; Based on the wheel acceleration change over 1 second, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius, determine the predicted wheel acceleration value and the corrected wheel acceleration value for each wheel at the current sampling time. Based on the predicted wheel acceleration value and the corrected wheel acceleration value, determine the slip ratio of each wheel at the current sampling moment; The second characteristic adhesion coefficient is determined based on the slip ratio and the second adhesion coefficient limit.

11. The vehicle speed determination method for a vehicle control system according to claim 10, characterized in that, The step of determining the 1-second change in wheel acceleration of each wheel at the current sampling time based on the first characteristic adhesion coefficient and the vertical force of each wheel at the current sampling time includes: Based on the first characteristic adhesion coefficient and the wheel vertical force, determine the longitudinal force of each wheel at the current sampling moment; The wheel acceleration change over 1 second is determined based on the longitudinal force of the wheel, the wheel radius of each wheel, the net wheel torque of each wheel at the current sampling time, and the wheel moment of inertia of each wheel at the current sampling time.

12. The vehicle speed determination method for a vehicle control system according to claim 10, characterized in that, The process of determining the predicted wheel acceleration value and the corrected wheel acceleration value for each wheel at the current sampling time based on the 1-second change in wheel acceleration, the wheel acceleration of each wheel at the previous sampling time, the wheel speed of each wheel at the current sampling time, and the wheel radius includes: The predicted value of wheel acceleration is determined based on the change in wheel acceleration over 1 second and the wheel acceleration of each wheel at the previous sampling time. The wheel acceleration correction value is determined based on the predicted wheel acceleration value, the wheel speed, and the wheel radius.

13. The vehicle speed determination method for a vehicle control system according to claim 12, characterized in that, The step of determining the slip ratio of each wheel at the current sampling moment based on the predicted wheel acceleration value and the corrected wheel acceleration value includes: Based on the predicted wheel acceleration value and the corrected wheel acceleration value, determine the wheel acceleration of each wheel at the current sampling time; Based on the wheel acceleration of each wheel at the current sampling time, determine the calculated wheel speed of each wheel at the current sampling time; Based on the calculated wheel speed and the longitudinal vehicle speed of the wheel, the slip ratio of each wheel at the current sampling moment is determined.

14. The vehicle speed determination method for a vehicle control system according to claim 10, characterized in that, Determining the second characteristic adhesion coefficient based on the slip ratio and the second adhesion coefficient limit includes: The second characteristic adhesion theoretical coefficient is determined based on the slip ratio and tire stiffness. When the second characteristic adhesion theoretical coefficient is less than or equal to the second adhesion coefficient limit, the second characteristic adhesion theoretical coefficient shall be used as the second characteristic adhesion coefficient. When the second characteristic adhesion theoretical coefficient is greater than the second adhesion coefficient limit, the second adhesion coefficient limit is used as the second characteristic adhesion coefficient.

15. The vehicle speed determination method for a vehicle control system according to claim 1, characterized in that, The process of determining the longitudinal vehicle speed observation value at the current sampling time based on the average wheel acceleration of each wheel includes: For any wheel, based on the mean wheel acceleration and the first wheel acceleration corresponding to several sampling moments in the current sampling period, determine the cumulative value of wheel acceleration variance and the wheel acceleration corresponding to several sampling moments in the current sampling period. Based on the wheel jerk, determine the mean wheel jerk and the cumulative variance of the wheel jerk; The reliability of the wheel acceleration for each wheel is determined based on the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of the wheel acceleration. The reliability of the wheel accelerometer for each wheel is determined based on the wheel accelerometer, the mean wheel accelerometer, and the cumulative variance of the wheel accelerometer. Based on the reliability of the wheel acceleration, the reliability of the wheel acceleration, the reliability of the wheel vertical force, the reliability of the difference between wheel speed and longitudinal vehicle speed, and the reliability of the difference between wheel acceleration and vehicle acceleration, the reliability of the wheel speed of each wheel is determined. When the vehicle is not in a counter-steering state and is not in a handbrake state, the vehicle speed observation value at the current sampling time is determined based on the reliability of the wheel speed of each wheel and the wheel speed of each wheel at the current sampling time. Based on the observed vehicle speed, the upper limit of vehicle speed, and the lower limit of vehicle speed, the longitudinal vehicle speed observed at the current sampling time is determined.

16. The vehicle speed determination method for a vehicle control system according to claim 15, characterized in that, The determination of the wheel speed reliability of each wheel based on the wheel acceleration reliability, wheel acceleration reliability, wheel vertical force reliability, wheel speed and longitudinal vehicle speed difference reliability, and wheel acceleration and vehicle acceleration difference reliability includes: For any wheel, the minimum reliability among the wheel acceleration reliability, wheel acceleration reliability, wheel vertical force reliability, wheel speed and longitudinal vehicle speed difference reliability, and wheel acceleration and vehicle acceleration difference reliability is taken as the wheel speed reliability of the corresponding wheel.

17. The vehicle speed determination method for a vehicle control system according to claim 15, characterized in that, The step of determining the reliability of the wheel acceleration of each wheel based on the first wheel acceleration, the mean wheel acceleration, and the cumulative variance of the wheel acceleration includes: The first confidence level is determined based on the first wheel acceleration and the average wheel acceleration. The second confidence level is determined based on the cumulative variance of the wheel acceleration. The lower of the first confidence level and the second confidence level is taken as the confidence level of the wheel acceleration.

18. The vehicle speed determination method for a vehicle control system according to claim 15, characterized in that, The step of determining the longitudinal vehicle speed observation value of the whole vehicle at the current sampling time based on the vehicle speed observation value, the upper limit of vehicle speed, and the lower limit of vehicle speed includes: When the observed vehicle speed value is greater than the lower limit of vehicle speed and less than the upper limit of vehicle speed, the observed vehicle speed value is used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time. When the observed vehicle speed is less than or equal to the lower limit of vehicle speed, the lower limit of vehicle speed shall be used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time. When the observed vehicle speed value is greater than or equal to the upper limit of vehicle speed, the upper limit of vehicle speed is used as the longitudinal vehicle speed observed value of the whole vehicle at the current sampling time.

19. The vehicle speed determination method for a vehicle control system according to claim 1, characterized in that, The step of determining the estimated longitudinal speed of the vehicle at the current sampling time based on the observed longitudinal speed, the estimated longitudinal speed change over 1 second, and the first longitudinal acceleration includes: Based on the first longitudinal acceleration, determine the observed value of the longitudinal vehicle speed change over 1 second at the current sampling time; When the current sampling time is time i, the estimated longitudinal vehicle speed of the whole vehicle at the corresponding current sampling time is obtained by the following formula: WE i =VI i-1 +k 21 *(VJ-VM i-1 )+k 22 *(VK-VI i-1 ), Among them, VI i VM represents the estimated longitudinal speed of the vehicle at the current sampling time. i-1 VI is the estimated value of the longitudinal vehicle speed change over 1 second. i-1 The estimated longitudinal vehicle speed at the previous sampling time; VJ is the observed longitudinal vehicle speed change over 1 second, VK is the observed longitudinal vehicle speed; k 21 k is the first calibration coefficient at the current sampling time. 22 is the second calibration coefficient at the current sampling time, i > 1.

20. The vehicle speed determination method for a vehicle control system according to claim 19, characterized in that, The step of determining the longitudinal vehicle speed change over 1 second at the current sampling time based on the first longitudinal acceleration includes: When the vehicle is moving forward at the current sampling time, the observed value of the longitudinal vehicle speed change over 1 second satisfies the following formula: VJ = ax² + VM * VN, When the vehicle is not moving forward at the current sampling time, the observed value of the longitudinal vehicle speed change over 1 second satisfies the following formula: VJ = ax² - VM * VN, Where VJ is the observed change in longitudinal vehicle speed over 1 second, ax2 is the first longitudinal acceleration of the vehicle at the current sampling time, VM is the yaw rate of the vehicle at the current sampling time, and VN is the lateral speed of the vehicle at the current sampling time.

21. The vehicle speed determination method for a vehicle control system according to claim 1, characterized in that, The step of determining the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and the estimated lateral speed of the vehicle at the current sampling time includes: Based on the estimated longitudinal speed and lateral speed of the vehicle at the current sampling time, the longitudinal slip ratio of each wheel and the second wheel lateral force of each wheel at the current sampling time are determined; the second wheel lateral force is obtained by the lateral adhesion coefficient and the wheel vertical force of each wheel. Based on the longitudinal slip ratio, determine the third wheel longitudinal force of each wheel at the current sampling time; The lateral acceleration of the vehicle at the current sampling time is determined based on the vehicle mass, the front wheel angle, the longitudinal force of the third wheel, and the lateral force of the second wheel of each wheel at the current sampling time. Based on the lateral acceleration, the estimated longitudinal vehicle speed, and the yaw rate, determine the lateral speed change of the entire vehicle in 1 second at the current sampling time; Based on the lateral speed change over 1 second, the estimated lateral speed of the vehicle at the current sampling time is determined.

22. A vehicle speed determination device for a vehicle control system, characterized in that, include: The first processing unit is used to acquire the vehicle mass, the air resistance, front wheel steering angle, yaw rate, 1s change of the second largest wheel speed and lateral speed of the vehicle at the current sampling time, the wheel lateral force and the first wheel longitudinal force of each wheel at the current sampling time, the average wheel acceleration of each wheel in the current sampling period, the first characteristic adhesion coefficient of each wheel and the first adhesion coefficient limit of each wheel at the previous sampling time, the estimated value of the 1s change of the longitudinal speed of the vehicle at the previous sampling time and the estimated value of the longitudinal speed of the vehicle at the previous sampling time. The second processing unit is used to determine the longitudinal slope acceleration of the vehicle at the current sampling time based on the air resistance, the vehicle mass, the front wheel steering angle, the longitudinal force of the first wheel, the lateral force of the wheel, the 1s change of the second largest wheel speed, the yaw rate, and the lateral vehicle speed. The third processing unit is used to determine the first longitudinal acceleration of the vehicle at the current sampling time based on the longitudinal slope acceleration, the first adhesion coefficient limit, and the first characteristic adhesion coefficient. The fourth processing unit is used to determine the longitudinal speed observation value of the whole vehicle at the current sampling time based on the average wheel acceleration of each wheel. The fifth processing unit is used to determine the estimated longitudinal speed of the whole vehicle at the current sampling time based on the longitudinal speed observation value, the estimated longitudinal speed change value in 1 second, and the first longitudinal acceleration. The sixth processing unit is used to determine the estimated lateral speed of the vehicle at the current sampling time based on the estimated longitudinal speed and the estimated lateral speed of the vehicle at the current sampling time.

23. A vehicle speed determination device for a vehicle control system, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the vehicle speed determination method of the vehicle control system as described in any one of claims 1-21.

24. A computer-readable storage medium storing processor-executable instructions, characterized in that, The processor-executable instructions, when executed by the processor, are used to perform the vehicle speed determination method of the vehicle control system as described in any one of claims 1-21.

25. A vehicle testing device, characterized in that, This includes the vehicle control system speed determination device as described in claim 22 or the vehicle control system speed determination equipment as described in claim 23.

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