Method and system for determining vehicle state, and storage medium

Abstract

A method for determining a vehicle state. The vehicle state comprises the rotation speed of a wheel, the longitudinal velocity of a center of mass of a vehicle, the lateral velocity of the center of mass of the vehicle and a slope at which the vehicle is located. The method comprises the following steps: determining the rotation speed of a wheel at the current moment at least on the basis of the stiffness and rotation speed of the wheel at the previous moment and an electric shaft torque of an electric motor, wherein the rotation speed of the wheel at the current moment is used for correcting the received force and rotation speed of the wheel at the next moment; determining the longitudinal velocity of a center of mass of a vehicle and the lateral velocity of the center of mass of the vehicle at the current moment at least on the basis of the received force of the wheel at the current moment, wherein the received force of the wheel at the current moment is at least determined by means of the rotation speed of the wheel at the current moment; and determining a slope at the current moment at least on the basis of the longitudinal velocity of the center of mass of the vehicle and the lateral velocity of the center of mass of the vehicle at the current moment, wherein the slope at the current moment is used for correcting the longitudinal velocity of the center of mass of the vehicle and the lateral velocity of the center of mass of the vehicle at the next moment.

Description

Method, system and storage medium for determining vehicle status Technical Field

[0001] The present application relates to the field of vehicle control, and more particularly to a method for determining a vehicle state, a system for determining a vehicle state, and a computer-readable storage medium. Background Art

[0002] With the development of vehicle intelligence, more and more vehicles have functions such as advanced assisted driving and stability control, which place higher requirements on the accuracy of vehicle status.

[0003] Currently, measurement units such as global positioning systems, inertial measurement units, lidar, and image sensors are commonly used to collect vehicle status signals. Fusion algorithms are then used to process these signals to determine the vehicle's status. However, high-precision measurement units are expensive, while low-cost measurement units, due to their low precision, result in high observation noise, calibration errors, and observation delays.

[0004] Summary of the Invention

[0005] In order to solve or at least alleviate one or more of the above problems, the following technical solutions are provided.

[0006] According to a first aspect of the present application, a method for determining a vehicle state is provided, wherein the vehicle state includes the rotational speed of the wheel, the longitudinal speed and lateral speed of the center of mass of the vehicle, and the slope on which the vehicle is located, the method comprising the following steps: determining the rotational speed of the wheel at a current moment based at least on the stiffness, rotational speed and electric shaft torque of the motor of the wheel at a previous moment, wherein the rotational speed of the wheel at the current moment is used to correct the force and rotational speed of the wheel at the next moment; determining the longitudinal speed and lateral speed of the center of mass of the vehicle at the current moment based at least on the force of the wheel at the current moment, wherein the force of the wheel at the current moment is determined at least by the rotational speed of the wheel at the current moment; and determining the slope at the current moment based at least on the longitudinal speed and lateral speed of the center of mass of the vehicle at the current moment, wherein the slope at the current moment is used to correct the longitudinal speed and lateral speed of the center of mass of the vehicle at the next moment.

[0007] According to the method for determining a vehicle state according to an embodiment of the present application, the electric shaft torque includes a driving torque and a braking torque.

[0008] According to the method for determining the vehicle state described in one embodiment or any one of the above embodiments of the present application, determining the rotational speed of the wheel at the current moment based at least on the stiffness, rotational speed and electric shaft torque of the motor at the previous moment includes: determining the rate of change of the electric shaft rotational speed at the previous moment based on the stiffness, rotational speed and electric shaft torque of the wheel at the previous moment; determining the predicted rotational speed of the wheel at the current moment based on the rate of change of the electric shaft rotational speed at the previous moment and the rotational speed of the wheel at the previous moment; and performing a weighted averaging operation on the predicted rotational speed of the wheel at the current moment and the measured rotational speed of the wheel at the current moment using a filtering algorithm to determine the rotational speed of the wheel at the current moment.

[0009] According to the method for determining the vehicle state described in one embodiment or any one of the above embodiments of the present application, the force acting on the wheel at the current moment is obtained through the following steps: determining the longitudinal slip rate and lateral slip rate of the wheel at the current moment based at least on the rotational speed of the wheel at the current moment; and determining the force acting on the wheel at the current moment based at least on the longitudinal slip rate, lateral slip rate and stiffness of the wheel at the current moment.

[0010] According to the method for determining the vehicle state described in one embodiment or any one of the above embodiments of the present application, determining the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the current moment based at least on the force applied to the wheel at the current moment includes: determining the rate of change of the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the current moment based at least on the force applied to the wheel at the current moment; determining the longitudinal velocity of the center of mass of the vehicle at the current moment based at least on the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm; and determining the lateral velocity of the center of mass of the vehicle at the current moment based at least on the rate of change of the lateral velocity of the center of mass of the vehicle at the current moment using an integration algorithm.

[0011] According to the method for determining the vehicle state described in one embodiment or any one of the above embodiments of the present application, wherein the longitudinal velocity of the center of mass of the vehicle at the current moment is determined based on at least the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm, the method includes: determining the predicted longitudinal velocity of the center of mass of the vehicle at the current moment based on the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment and the longitudinal velocity of the center of mass of the vehicle at the previous moment; determining the longitudinal translational velocity and lateral translational velocity of the wheel at the current moment based on the rotational speed of the wheel at the current moment and the longitudinal slip rate of the wheel at the previous moment; determining the observed longitudinal velocity of the center of mass of the vehicle at the current moment based on vector processing of the longitudinal translational velocity and lateral translational velocity of the wheel at the current moment; and performing a weighted averaging operation on the predicted longitudinal velocity of the center of mass of the vehicle at the current moment and the observed longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm to determine the longitudinal velocity of the center of mass of the vehicle at the current moment.

[0012] According to the method for determining the vehicle state described in one embodiment or any one of the above embodiments of the present application, wherein the lateral velocity of the center of mass of the vehicle at the current moment is determined based on at least the rate of change of the lateral velocity of the center of mass of the vehicle at the current moment using an integral algorithm, the method includes: determining the lateral velocity of the center of mass of the vehicle at the current moment based on the integral of the rate of change of the lateral velocity of the center of mass of the vehicle at the current moment over time and the sum of the lateral velocity of the center of mass of the vehicle at the previous moment.

[0013] According to the method for determining the state of a vehicle described in one embodiment or any one of the above embodiments of the present application, the slope at the current moment is used to correct the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the next moment in the following manner: determining the rate of change of the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the next moment based at least on the slope and yaw angular velocity at the current moment; correcting the longitudinal velocity of the center of mass of the vehicle at the next moment based at least on the rate of change of the longitudinal velocity of the center of mass of the vehicle at the next moment using a filtering algorithm; and correcting the lateral velocity of the center of mass of the vehicle at the next moment based at least on the rate of change of the lateral velocity of the center of mass of the vehicle at the next moment using an integration algorithm.

[0014] According to the method for determining the vehicle state according to one embodiment or any one of the above embodiments of the present application, the method also includes: determining the longitudinal translation correction speed and lateral translation correction speed of the wheel at the current moment based on vector processing of the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment; and using the longitudinal translation correction speed and lateral translation correction speed of the wheel at the current moment to correct the force, longitudinal slip rate and lateral slip rate of the wheel at the next moment.

[0015] According to the method for determining the vehicle state according to one embodiment or any one of the above embodiments of the present application, determining the slope at the current moment based at least on the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment includes: determining the longitudinal slope angle at the current moment based at least on the lateral velocity of the center of mass, the longitudinal velocity of the center of mass and the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment; determining the transverse slope angle at the current moment based at least on the lateral velocity of the center of mass, the longitudinal velocity of the center of mass and the rate of change of the lateral velocity of the center of mass of the vehicle at the current moment; and determining the longitudinal slope angle at the current moment and the transverse slope angle at the current moment as the slope at the current moment.

[0016] According to the method for determining the vehicle state according to one embodiment or any one of the above embodiments of the present application, the method further includes: using a first low-pass filter to process the longitudinal slope angle at the current moment; using a second low-pass filter to process the transverse slope angle at the current moment; wherein the cutoff frequency of the first low-pass filter and the cutoff frequency of the second low-pass filter are adjusted in response to the vehicle being in a transient operating condition or a steady-state operating condition.

[0017] According to the method for determining the state of a vehicle described in one embodiment or any one of the above embodiments of the present application, wherein the cutoff frequency of the first low-pass filter is adjusted in response to the vehicle being in a transient operating condition or a steady-state operating condition, the method includes: determining whether the vehicle is in a transient operating condition or a steady-state operating condition based on one or more of the rate of change of the longitudinal acceleration of the center of mass, the rate of change of the longitudinal velocity of the center of mass, the rate of change of the lateral velocity of the center of mass, and the rate of change of the yaw angular velocity; and adjusting the cutoff frequency of the first low-pass filter in response to the vehicle being determined to be in a transient operating condition or a steady-state operating condition.

[0018] According to the method for determining the state of a vehicle according to one embodiment or any one of the above embodiments of the present application, wherein the cutoff frequency of the second low-pass filter is adjusted in response to the vehicle being in a transient operating condition or a steady-state operating condition, the method includes: determining whether the vehicle is in a transient operating condition or a steady-state operating condition based on one or more of the rate of change of the center of mass lateral acceleration, the rate of change of the center of mass lateral velocity, the rate of change of the center of mass longitudinal velocity, and the rate of change of the yaw angular velocity; and adjusting the cutoff frequency of the second low-pass filter in response to the vehicle being determined to be in a transient operating condition or a steady-state operating condition.

[0019] According to a second aspect of the present application, a system for determining a vehicle status is provided, the system comprising: a memory; a processor coupled to the memory; and a computer program stored on the memory and running on the processor, the execution of the computer program resulting in the execution of the steps of the method for determining a vehicle status according to the first aspect of the present application.

[0020] According to a third aspect of the present application, a computer storage medium is provided, which includes instructions, and when the instructions are executed, the steps of the method for determining a vehicle state according to the first aspect of the present application are executed.

[0021] The scheme for determining the vehicle state according to one or more embodiments of the present application can fully consider the lateral and longitudinal mechanical characteristics of the wheel, the electric shaft torque of the motor, the force applied to the wheel and the slope, thereby realizing early prediction of the vehicle state, reducing or eliminating the time lag of the vehicle state data directly collected by the measurement unit, and forming a closed-loop correction of the wheel speed and a closed-loop correction of the longitudinal velocity and lateral velocity of the center of mass of the vehicle by the slope, so as to obtain high-precision vehicle state data with low latency, and provide robust and reliable input for subsequent advanced driver assistance, stability control and other functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or other aspects and advantages of the present application will become clearer and easier to understand through the following description of various aspects in conjunction with the accompanying drawings, in which the same or similar elements are represented by the same reference numerals. The accompanying drawings include:

[0023] FIG1 shows a flowchart of a method for determining a vehicle state according to one or more embodiments of the present application.

[0024] FIG2 shows a flow chart of a closed-loop correction process for a wheel rotation speed according to one or more embodiments of the present application.

[0025] FIG3 shows a flow chart of a closed-loop correction of the center-of-mass velocity of a vehicle according to one or more embodiments of the present application.

[0026] FIG4 shows a flow chart of a closed-loop correction process for slope according to one or more embodiments of the present application.

[0027] FIG5 shows a block diagram of a system for determining a vehicle state according to one or more embodiments of the present application. DETAILED DESCRIPTION

[0028] The present application is described more fully below with reference to the accompanying drawings, which illustrate exemplary embodiments of the present application. However, the present application may be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. The foregoing embodiments are provided to make the disclosure herein comprehensive and complete, so as to more fully convey the scope of protection of the present application to those skilled in the art.

[0029] In this specification, terms such as "comprise" and "include" indicate that in addition to the units and steps directly and clearly stated in the specification and claims, the technical solution of this application does not exclude the situation where it has other units and steps that are not directly or clearly stated.

[0030] Unless otherwise specified, terms such as "first" and "second" do not indicate the order of units in terms of time, space, size, etc., but are only used to distinguish between units.

[0031] In the context of the present application, the vehicle state may include, but is not limited to, the rotational speed of the wheels, the longitudinal velocity and lateral velocity of the center of mass of the vehicle, and the slope of the vehicle. It should be noted that the solution for determining the vehicle state according to one or more embodiments of the present application may be applied to each wheel of the vehicle to determine the vehicle state for each wheel.

[0032] Hereinafter, various exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings.

[0033] FIG1 shows a flowchart of a method for determining a vehicle state according to one or more embodiments of the present application.

[0034] As shown in FIG1 , in step S101 , the wheel speed at the current moment is determined based at least on the wheel stiffness, speed and motor shaft torque at the previous moment, and the wheel speed at the current moment is used to correct the wheel force and speed at the next moment.

[0035] Alternatively, the wheel stiffness can be obtained by querying a pre-calibrated database or using a pre-trained neural network model. Alternatively, the electric shaft torque can include driving torque and braking torque. For example, the driving torque can be calculated using the motor voltage and current, and the braking torque can be estimated using the brake caliper pressure and friction coefficient.

[0036] Optionally, in step S101, the electric shaft speed change rate at the previous moment can be determined based on the stiffness, speed and electric shaft torque of the wheel at the previous moment, the predicted speed of the wheel at the current moment can be determined based on the electric shaft speed change rate at the previous moment and the speed of the wheel at the previous moment, and a filtering algorithm (for example, a Kalman filtering algorithm) can be used to perform a weighted averaging operation on the predicted speed of the wheel at the current moment and the measured speed of the wheel at the current moment to determine the speed of the wheel at the current moment.

[0037] In one embodiment, the electric shaft speed change rate w_dot can be determined by the following formula (1): Twhl-FxWhlPred*r=J*w_dot Formula (1)

[0038] Wherein, Twhl represents the sum of the driving torque and braking torque of the electric shaft, FxWhlPred represents the longitudinal force of the wheel, r represents the wheel radius, and J represents the sum of the rotational inertia of the wheel and the electric shaft.

[0039] In one embodiment, the longitudinal force FxWhlPred of the wheel can be determined by the following formula (2): FxWhlPred=Fz*SlipLng*Cx Formula (2)

[0040] Wherein, Fz represents the vertical load of the wheel, SlipLng represents the longitudinal slip of the wheel, and Cx represents the longitudinal stiffness of the wheel. Optionally, the longitudinal slip SlipLng of the wheel and the longitudinal stiffness Cx of the wheel can be determined based on at least the rotation speed of the wheel at the last moment.

[0041] In one embodiment, the predicted wheel speed wPred(k) at the current moment can be determined by the following formula (3): wPred(k)=wCorr(k-1)+w_dot*dT Formula (3)

[0042] Where k and k-1 represent the current moment and the previous moment, respectively; wCorr(k-1) represents the wheel speed at the previous moment; w_dot represents the rate of change of the electric shaft speed; and dT represents the derivative of the operation cycle.

[0043] In one embodiment, the Kalman filter algorithm can be used to perform a weighted average operation on the predicted wheel speed wPred(k) and the measured wheel speed wMeas(k) at the current moment by the following formula (4) to determine the wheel speed wCorr(k) at the current moment: wCorr(k) = wPred(k)*i + wMeas(k)*(1-i) Formula (4)

[0044] Wherein, i and 1-i represent weights of weighted average, i∈(0,1). Exemplarily, i can be set to a value greater than 0.9 and less than 1.

[0045] According to one or more embodiments of the present application, the longitudinal slip SlipLng of the wheel, the longitudinal stiffness Cx of the wheel, and the predicted speed wPred(k) of the wheel at the current moment can be determined based on at least the speed wCorr(k-1) of the wheel at the previous moment. Optionally, at the next moment, the speed of the wheel at the current moment determined in step S101 can be implemented as a closed-loop correction value and used as the speed of the wheel at the previous moment to determine the longitudinal slip SlipLng of the wheel, the longitudinal stiffness Cx of the wheel, and the predicted speed of the wheel at the current moment, thereby improving the accuracy of the longitudinal slip SlipLng of the wheel, the longitudinal stiffness Cx of the wheel, and the predicted speed of the wheel at the current moment. According to one or more embodiments of the present application, the torque balance equation as described in the above formula (1) is constructed by the electric shaft torque of the motor and the force on the wheel to determine the electric shaft speed change rate, and the electric shaft speed change rate is used to further predict the speed of the wheel at the current moment, thereby reducing or eliminating the time lag of the wheel speed directly collected by the measurement unit. In addition, the wheel speed at the current moment can be used to correct the force and speed of the wheel at the next moment (for example, refer to the above formula (3)), thereby forming a closed-loop correction of the wheel speed, further improving the accuracy of the wheel speed determined thereby.

[0046] In step S103, the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the current moment are determined based at least on the force applied to the wheel at the current moment, where the force applied to the wheel at the current moment is determined at least by the rotation speed of the wheel at the current moment.

[0047] Optionally, the force acting on the wheel at the current moment may include longitudinal force and lateral force, which can be obtained through the following steps: determining the longitudinal slip rate and lateral slip rate of the wheel at the current moment based at least on the rotation speed of the wheel at the current moment, and determining the force acting on the wheel at the current moment based at least on the longitudinal slip rate, lateral slip rate and stiffness of the wheel at the current moment.

[0048] In one embodiment, the longitudinal slip rate SlipLng(k) of the wheel at the current moment can be determined by the following formula (5): SlipLng(k)=(wCorr(k)*r-VxWhl(k-1)) / max(wCorr(k)*r,VxWhl(k-1)) Formula (5)

[0049] Where k and k-1 represent the current moment and the previous moment respectively, wCorr(k) represents the wheel speed at the current moment, r represents the wheel radius, and VxWhl(k-1) represents the longitudinal translation speed of the wheel at the previous moment.

[0050] In one embodiment, the lateral slip rate SlipLat(k) of the wheel at the current moment can be determined by the following formula (6): SlipLat(k)=VyWhl(k-1) / VxWhl(k-1) Formula (6)

[0051] Among them, k and k-1 represent the current moment and the previous moment respectively, VyWhl(k-1) represents the lateral translation speed of the wheel at the previous moment, and VxWhl(k-1) represents the longitudinal translation speed of the wheel at the previous moment.

[0052] Optionally, the force on the wheel at the current moment may include longitudinal force and lateral force. In one embodiment, the longitudinal force FxWhl(k) on the wheel at the current moment may be determined by the following formula (7): FxWhl(k) = Fz(k)*SlipLng(k)*Cx(k) Formula (7)

[0053] Where Fz(k) represents the vertical load of the wheel at the current moment, SlipLng(k) represents the longitudinal slip rate of the wheel at the current moment, and Cx(k) represents the longitudinal stiffness of the wheel at the current moment.

[0054] In one embodiment, the lateral force FyWhl(k) of the wheel at the current moment can be determined by the following formula (8): FyWhl(k)=Fz(k)*MueY(k) Formula (8)

[0055] Where Fz(k) represents the vertical load of the wheel at the current moment, and MueY(k) represents the lateral friction coefficient of the wheel relative to the ground at the current moment.

[0056] Optionally, in step S103, the longitudinal velocity change rate of the center of mass of the vehicle at the current moment and the lateral velocity change rate of the center of mass of the vehicle at the current moment can be determined at least based on the force applied to the wheel at the current moment determined by the rotational speed of the wheel at the current moment, and the longitudinal velocity of the center of mass of the vehicle at the current moment can be determined based at least on the longitudinal velocity change rate of the center of mass of the vehicle at the current moment using a filtering algorithm (for example, a Kalman filtering algorithm), and the lateral velocity of the center of mass of the vehicle at the current moment can be determined based at least on the lateral velocity change rate of the center of mass of the vehicle at the current moment using an integration algorithm.

[0057] In one embodiment, determining the longitudinal velocity of the center of mass of the vehicle at the current moment based on at least the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm may include: determining the predicted longitudinal velocity of the center of mass of the vehicle at the current moment based on the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment and the longitudinal velocity of the center of mass of the vehicle at the previous moment; determining the longitudinal translation velocity and lateral translation velocity of the wheel at the current moment based on the rotational speed of the wheel at the current moment and the longitudinal slip rate of the wheel at the previous moment; determining the observed longitudinal velocity of the center of mass of the vehicle at the current moment based on vector processing of the longitudinal translation velocity and lateral translation velocity of the wheel at the current moment; and performing a weighted averaging operation on the predicted longitudinal velocity of the center of mass of the vehicle at the current moment and the observed longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm to determine the longitudinal velocity of the center of mass of the vehicle at the current moment.

[0058] In one embodiment, the predicted longitudinal velocity of the vehicle's center of mass at the current moment VxVehPred(k) can be determined by the following formula (9): VxVehPred(k)=VxVehCorr(k-1)+dVxVeh / dT(k)*dT Formula (9)

[0059] Where k and k-1 represent the current moment and the previous moment, respectively, VxVehCorr(k-1) represents the longitudinal velocity of the vehicle's center of mass at the previous moment, dVxVeh / dT(k) represents the rate of change of the longitudinal velocity of the vehicle's center of mass at the current moment, and dT represents the derivative of the operation cycle.

[0060] In one embodiment, the observed longitudinal velocity of the vehicle's center of mass at the current moment VxVehMeas(k) can be determined by the following formula (10): VxVehMeas(k)=f(VxWhl(k),VyWhl(k),YawRate(k),WhlStrAng(k)) Formula (10)

[0061] Among them, VxWhl(k) represents the longitudinal translation velocity of the wheel at the current moment, VyWhl(k) represents the lateral translation velocity of the wheel at the current moment, YawRate(k) represents the yaw angular velocity of the vehicle at the current moment, WhlStrAng(k) represents the turning angle of the wheel at the current moment, and f represents vector processing, which is used to translate and rotate the longitudinal translation velocity VxWhl(k) and lateral translation velocity VyWhl(k) of the wheel at the current moment into the longitudinal velocity of the vehicle's center of mass.

[0062] In one embodiment, the vehicle's center-of-mass longitudinal velocity VxVehCorr(k) at the current moment can be determined using the Kalman filter algorithm based on the results of formulas (9) and (10) using the following formula (11): VxVehCorr(k)=VxVehMeas(k)*i+VxVehPred(k)*(1-i) Formula (11)

[0063] Wherein, i and 1-i represent weights of weighted average, i∈(0,1). Exemplarily, i can be set to a value greater than 0 and less than 0.2.

[0064] In one embodiment, determining the current moment's lateral velocity of the vehicle's center of mass based on at least the current moment's rate of change of the vehicle's center of mass lateral velocity using an integral algorithm may include: determining the current moment's lateral velocity of the vehicle's center of mass based on the sum of the current moment's rate of change of the center of mass lateral velocity over time and the vehicle's center of mass lateral velocity at a previous moment. In one embodiment, the current moment's lateral velocity of the vehicle's center of mass VyVeh(k) may be determined using the following formula (12): VyVeh(k) = VyVeh(k-1) + dVyVeh / dT(k)*dT Formula (12)

[0065] Where k and k-1 represent the current moment and the previous moment, respectively. VyVeh(k-1) represents the lateral velocity of the vehicle's center of mass at the previous moment. dVyVeh / dT(k) represents the rate of change of the lateral velocity of the vehicle's center of mass at the current moment. dT represents the derivative of the calculation period.

[0066] Optionally, in one or more embodiments of the present application, after determining the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment, the longitudinal translation correction velocity and the lateral translation correction velocity of the wheel at the current moment can be determined based on the vector processing of the longitudinal velocity and the lateral velocity of the center of mass of the vehicle at the current moment (i.e., refer to the inverse transformation of the above formula (10)), and the longitudinal translation correction velocity and the lateral translation correction velocity of the wheel at the current moment can be used to correct the force, longitudinal slip rate and lateral slip rate of the wheel at the next moment.

[0067] In step S105, the slope at the current moment is determined based at least on the vehicle's center of mass longitudinal velocity and center of mass lateral velocity at the current moment, and the slope at the current moment is used to correct the vehicle's center of mass longitudinal velocity and center of mass lateral velocity at the next moment.

[0068] Optionally, in step S105, the longitudinal slope angle at the current moment can be determined at least based on the vehicle's center of mass lateral velocity, center of mass longitudinal velocity and center of mass longitudinal velocity change rate at the current moment, and the transverse slope angle at the current moment can be determined at least based on the vehicle's center of mass lateral velocity, center of mass longitudinal velocity and center of mass lateral velocity change rate at the current moment, and the longitudinal slope angle at the current moment and the transverse slope angle at the current moment are determined as the slope at the current moment.

[0069] In one embodiment, the longitudinal slope angle SlopAng(k) at the current moment can be determined by the following formula (13): gsin(SlopAng(k))=Ax_Sensor(k)-dVxVeh / dT(k)+VyVeh(k)*YawRate(k) Formula (13)

[0070] Where g represents the acceleration due to gravity, Ax_Sensor(k) represents the current measured value of the longitudinal acceleration, dVxVeh / dT(k) represents the rate of change of the longitudinal velocity of the vehicle's center of mass at the current moment, VyVeh(k) represents the current lateral velocity of the vehicle's center of mass, and YawRate(k) represents the current yaw rate of the vehicle.

[0071] In one embodiment, the current slope angle BankAng(k) can be determined by the following formula (14): gsin(BankAng(k))=Ay_Sensor(k)-dVyVeh / dT(k)-VxVeh(k)*YawRate(k) Formula (14)

[0072] Where g represents the acceleration due to gravity, Ay_Sensor(k) represents the measured value of the lateral acceleration at the current moment, dVyVeh / dT(k) represents the rate of change of the lateral velocity of the vehicle's center of mass at the current moment, VxVeh(k) represents the longitudinal velocity of the vehicle's center of mass at the current moment, and YawRate(k) represents the yaw angular velocity of the vehicle at the current moment.

[0073] Optionally, after determining the longitudinal slope angle and the transverse slope angle at the current moment, a low-pass filter may be performed on the longitudinal slope angle and the transverse slope angle at the current moment. Optionally, the cutoff frequency of the low-pass filter may be adjusted in response to whether the vehicle is in a transient operating condition or a steady-state operating condition. Alternatively, after determining the longitudinal slope angle and the transverse slope angle at the current moment, a recursive least squares method may be performed on the longitudinal slope angle and the transverse slope angle at the current moment. Optionally, the forgetting factor of the recursive least squares method may be adjusted in response to whether the vehicle is in a transient operating condition or a steady-state operating condition.

[0074] In one embodiment, a first low-pass filter can be used to process the longitudinal slope angle at the current moment, and a second low-pass filter can be used to process the transverse slope angle at the current moment, wherein the cutoff frequency of the first low-pass filter and the cutoff frequency of the second low-pass filter are adjusted in response to whether the vehicle is in a transient operating condition or a steady-state operating condition. In one embodiment, whether the vehicle is in a transient operating condition or a steady-state operating condition can be determined based on one or more of the rate of change of the longitudinal acceleration of the center of mass, the rate of change of the longitudinal velocity of the center of mass (which can be determined by the ratio of the change in the longitudinal velocity of the center of mass to the time taken for the change to occur), the rate of change of the lateral velocity of the center of mass, and the rate of change of the yaw rate, and the cutoff frequency of the first low-pass filter is adjusted in response to the vehicle being determined to be in a transient operating condition or a steady-state operating condition. In one embodiment, the vehicle can be determined to be in a transient or steady-state operating condition based on one or more of the rate of change of the center-of-mass lateral acceleration, the rate of change of the center-of-mass lateral velocity (which can be determined by the ratio of the amount of change in the center-of-mass lateral velocity to the time it takes to occur), the rate of change of the center-of-mass longitudinal velocity, and the rate of change of the yaw rate. In response to the determination that the vehicle is in a transient or steady-state operating condition, the cutoff frequency of the second low-pass filter can be adjusted. Similarly, the forgetting factor of the recursive least squares method can also be similarly adjusted based on the vehicle's operating condition.

[0075] It should be noted that the vehicle being in a transient state can be understood as the rate of change of the vehicle's steering wheel angle and / or vehicle speed exceeding the corresponding threshold, and the vehicle being in a steady state can be understood as the rate of change of the vehicle's steering wheel angle and / or vehicle speed not exceeding the corresponding threshold. For example, the threshold for the steering wheel angle can be set to about 1 degree, and the threshold for the rate of change of the vehicle speed can be set to 0.5 m / s. 2 By adjusting the cutoff frequency of the low-pass filter or the forgetting factor of the recursive least squares method, the slope update speed can be accelerated under steady-state conditions (i.e., the weight of the slope history value is reduced and the weight of the current slope value is increased). The slope update speed can be slowed down under transient conditions (i.e., the weight of the slope history value is increased and the weight of the current slope value is reduced), thereby improving the accuracy of the slope.

[0076] The scheme for determining the vehicle state according to one or more embodiments of the present application can fully consider the lateral and longitudinal mechanical characteristics of the wheel, the electric shaft torque of the motor, the force applied to the wheel and the slope, thereby realizing early prediction of the vehicle state, reducing or eliminating the time lag of the vehicle state data directly collected by the measurement unit, and forming a closed-loop correction of the wheel speed and a closed-loop correction of the longitudinal velocity and lateral velocity of the center of mass of the vehicle by the slope, so as to obtain high-precision vehicle state data with low latency, and provide robust and reliable input for subsequent advanced driver assistance, stability control and other functions.

[0077] FIG2 shows a flow chart of a closed-loop correction process for a wheel rotation speed according to one or more embodiments of the present application.

[0078] As shown in FIG2 , in step S201, the longitudinal stiffness of the wheel is determined. Optionally, the longitudinal stiffness of the wheel can be obtained by querying a pre-calibrated database or by using a pre-trained neural network model, wherein the pre-calibrated database or the pre-trained neural network model is generated or trained based on at least the rotational speed of the wheel.

[0079] In step S203, the longitudinal slip ratio of the wheel is determined. Alternatively, the longitudinal slip ratio of the wheel at the current moment can be determined based at least on the rotation speed of the wheel at the current moment by referring to the above formula (5).

[0080] In step S205, the longitudinal force of the wheel is determined. Alternatively, the longitudinal force of the wheel can be determined by referring to the above formula (2).

[0081] In step S207, the predicted rotational speed of the wheel is determined. Alternatively, the predicted rotational speed of the wheel at the current moment can be determined by referring to the above formula (3).

[0082] In step S209, the wheel speed is determined. Optionally, the wheel speed can be determined by performing a weighted average operation on the predicted wheel speed and the measured wheel speed at the current moment using a filtering algorithm with reference to the above formula (4).

[0083] After determining the rotational speed of the wheel at the current moment, at the next moment, the rotational speed of the wheel at the current moment determined in step S209 can be fed back to steps S201, S203 and S207 as the rotational speed of the wheel at the previous moment, thereby realizing closed-loop correction of the longitudinal stiffness in step S201, the longitudinal slip rate in step S203 and the predicted rotational speed of the wheel in step S207, thereby improving the accuracy of the longitudinal stiffness in step S201, the longitudinal slip rate in step S203 and the predicted rotational speed of the wheel in step S207.

[0084] FIG3 shows a flow chart of a closed-loop correction of the center-of-mass velocity of a vehicle according to one or more embodiments of the present application.

[0085] As shown in FIG3 , in step S301 , the wheel slip rate is determined. Alternatively, the longitudinal slip rate and lateral slip rate of the wheel at the current moment can be determined by referring to the above formulas (5) and (6).

[0086] In step S303, the forces acting on the wheels are determined. Alternatively, the longitudinal forces and lateral forces acting on the wheels at the current moment can be determined by referring to the above formulas (7) and (8).

[0087] In step S305 , the longitudinal velocity change rate and the lateral velocity change rate of the center of mass are determined.

[0088] In step S307, the longitudinal velocity of the center of mass is determined based on the rate of change of the longitudinal velocity of the center of mass. Alternatively, the longitudinal velocity of the center of mass of the vehicle at the current moment can be determined by using a filtering algorithm with reference to the above formula (11).

[0089] In step S309, the center-of-mass lateral velocity is determined based on the center-of-mass lateral velocity change rate. Alternatively, the center-of-mass lateral velocity of the vehicle at the current moment may be determined by referring to the above formula (12).

[0090] After determining the longitudinal velocity and lateral velocity of the vehicle's center of mass, at the next moment, the longitudinal velocity and lateral velocity of the vehicle's center of mass determined in step S307 and step S309 respectively can be vector processed to generate the longitudinal translation velocity and lateral translation velocity of the wheel (i.e., refer to the inverse transformation of the above formula (10)), and the generated longitudinal translation velocity and lateral translation velocity of the wheel are fed back to step S301 as the longitudinal translation velocity and lateral translation velocity of the wheel at the previous moment, thereby realizing closed-loop correction of the slip rate of the wheel in step 301, thereby improving the accuracy of the slip rate of the wheel in step S301.

[0091] FIG4 shows a flow chart of a closed-loop correction process for slope according to one or more embodiments of the present application.

[0092] As shown in FIG4 , the slope is determined based on at least the longitudinal velocity and transverse velocity of the center of mass of the vehicle. Optionally, the longitudinal slope angle and transverse slope angle at the current moment can be determined with reference to the above formulas (13) and (14). After the longitudinal slope angle and transverse slope angle are determined, at the next moment, the longitudinal slope angle and transverse slope angle can be fed back to step S305 to determine the longitudinal velocity change rate and transverse velocity change rate of the center of mass of the vehicle at the current moment as the longitudinal slope angle and transverse slope angle at the previous moment, thereby respectively determining the longitudinal velocity and transverse velocity of the center of mass of the vehicle at the current moment using a filtering algorithm and an integral algorithm, thereby achieving closed-loop correction of the longitudinal velocity and transverse velocity of the center of mass of the vehicle by the slope, and improving the accuracy of the longitudinal velocity and transverse velocity of the center of mass of the vehicle.

[0093] Exemplarily, the cross slope angle can be used to determine the cross slope gravity acceleration component, thereby determining the rate of change of the vehicle's center of mass lateral velocity, so as to determine the vehicle's center of mass lateral velocity by means of the above formula (12). Exemplarily, the longitudinal slope angle can be used to determine the longitudinal slope gravity acceleration component, thereby determining the rate of change of the vehicle's center of mass longitudinal velocity, so as to determine the vehicle's predicted center of mass longitudinal velocity by means of the above formula (9), so as to determine the vehicle's center of mass longitudinal velocity using the above formula (11) using a filtering algorithm.

[0094] FIG5 shows a block diagram of a system for determining a vehicle state according to one or more embodiments of the present application.

[0095] As shown in Figure 5, the system 50 for determining the vehicle status includes a communication unit 510, a memory 520 (for example, a non-volatile memory such as flash memory, ROM, hard disk drive, magnetic disk, optical disk), a processor 530, and a computer program 540 stored on the memory 520 and executable on the processor 530.

[0096] The communication unit 510 serves as a communication interface and is configured to establish a communication connection between the task scheduling system 50 and an external device or network (eg, a cloud, a mobile terminal, etc.).

[0097] The memory 520 stores a computer program 540 executable by the processor 530. Furthermore, the memory 520 may store data generated when the processor 530 executes the computer program (e.g., wheel rotation speed, longitudinal and lateral velocity of the vehicle's center of mass, slope, etc.), and data or commands received from the outside via the communication unit 510.

[0098] The processor 530 is configured to execute the computer program 540 to implement the method for determining the vehicle state according to one or more embodiments of the present application.

[0099] According to one or more embodiments of the present application, the system for determining the vehicle state can fully consider the lateral and longitudinal mechanical characteristics of the wheel, the electric shaft torque of the motor, the force applied to the wheel and the slope, thereby realizing early prediction of the vehicle state, reducing or eliminating the time lag of the vehicle state data directly collected by the measurement unit, and forming a closed-loop correction of the wheel speed and the slope to the longitudinal velocity and lateral velocity of the vehicle's center of mass, so as to obtain high-precision vehicle state data with low latency, and provide robust and reliable input for subsequent advanced driver assistance, stability control and other functions.

[0100] In the applicable situation, the combination of hardware, software or hardware and software can be used to realize the various embodiments provided by the application. Moreover, in the applicable situation, without departing from the scope of the application, the various hardware components and / or software components set forth herein can be combined into a composite component comprising software, hardware and / or both. In the applicable situation, without departing from the scope of the application, the various hardware components and / or software components set forth herein can be divided into a subcomponent comprising software, hardware or both. In addition, in the applicable situation, it is contemplated that the software component can be implemented as a hardware component, and vice versa.

[0101] Software according to the present application (such as program code and / or data) can be stored on one or more computer storage media. It is also contemplated that the software identified herein can be implemented using one or more general or special computers and / or computer systems, networked and / or otherwise. Where applicable, the order of the various steps described herein can be changed, combined into composite steps and / or divided into sub-steps to provide the features described herein.

[0102] The embodiments and examples set forth herein are provided to best illustrate embodiments according to the present application and its specific applications, and thereby enable those skilled in the art to make and use the present application. However, those skilled in the art will appreciate that the above description and examples are provided for ease of illustration and example only. The descriptions set forth are not intended to be exhaustive of all aspects of the present application or to limit the present application to the precise forms disclosed.

Claims

1. A method for determining a vehicle state, characterized in that The vehicle state includes the rotation speed of the wheels, the longitudinal speed of the center of mass of the vehicle, the lateral speed of the center of mass of the vehicle, and the slope of the vehicle. The method includes the following steps: Determine the rotation speed of the wheel at a current moment based at least on the stiffness and rotation speed of the wheel at a previous moment and the electric shaft torque of the motor, wherein the rotation speed of the wheel at the current moment is used to correct the force and rotation speed of the wheel at a next moment; Determine the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment at least based on the force applied to the wheel at the current moment, wherein the force applied to the wheel at the current moment is determined at least by the rotation speed of the wheel at the current moment; as well as The slope at the current moment is determined based at least on the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment, and the slope at the current moment is used to correct the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the next moment. 2 . The method according to claim 1 , wherein the electric shaft torque comprises a driving torque and a braking torque.

3. The method according to claim 1, wherein determining the rotation speed of the wheel at the current moment based on at least the stiffness and rotation speed of the wheel at the previous moment and the electric shaft torque of the motor comprises: Determine the rate of change of the electric shaft speed at the last moment based on the stiffness and speed of the wheel and the electric shaft torque of the motor at the last moment; Determining the predicted rotation speed of the wheel at the current moment based on the electric shaft rotation speed change rate at the previous moment and the rotation speed of the wheel at the previous moment; as well as A weighted average operation is performed on the predicted rotation speed of the wheel at the current moment and the measured rotation speed of the wheel at the current moment by using a filtering algorithm to determine the rotation speed of the wheel at the current moment.

4. The method according to claim 1, wherein the force of the wheel at the current moment is obtained by the following steps: Determining a longitudinal slip ratio and a lateral slip ratio of the wheel at the current moment based at least on the rotation speed of the wheel at the current moment; and The force of the wheel at the current moment is determined based on at least the longitudinal slip rate, the lateral slip rate and the stiffness of the wheel at the current moment.

5. The method according to claim 1, wherein determining the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the current moment based at least on the force of the wheel at the current moment comprises: Determine the longitudinal velocity change rate and the lateral velocity change rate of the center of mass of the vehicle at the current moment based at least on the force applied to the wheel at the current moment; Determine the longitudinal velocity of the center of mass of the vehicle at the current moment based on at least the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment using a filtering algorithm; as well as The center-of-mass lateral velocity of the vehicle at the current moment is determined by using an integration algorithm based at least on the rate of change of the center-of-mass lateral velocity of the vehicle at the current moment.

6. The method according to claim 5, wherein determining the longitudinal velocity of the center of mass of the vehicle at the current moment based on at least the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment by using a filtering algorithm comprises: Determining a predicted longitudinal velocity of the center of mass of the vehicle at the current moment based on the rate of change of the longitudinal velocity of the center of mass of the vehicle at the current moment and the longitudinal velocity of the center of mass of the vehicle at the previous moment; Determining the longitudinal translation speed and the lateral translation speed of the wheel at the current moment based on the rotation speed of the wheel at the current moment and the longitudinal slip rate of the wheel at the previous moment; Determining the observed center-of-mass longitudinal velocity of the vehicle at the current moment based on vector processing of the longitudinal translation velocity and the lateral translation velocity of the wheel at the current moment; as well as A weighted average operation is performed on the predicted longitudinal velocity of the center of mass of the vehicle at the current moment and the observed longitudinal velocity of the center of mass of the vehicle at the current moment by using a filtering algorithm to determine the longitudinal velocity of the center of mass of the vehicle at the current moment.

7. The method according to claim 5, wherein determining the lateral velocity of the center of mass of the vehicle at the current moment based on at least the rate of change of the lateral velocity of the center of mass of the vehicle at the current moment by using an integral algorithm comprises: The lateral velocity of the center of mass of the vehicle at the current moment is determined based on the sum of the integral of the rate of change of the lateral velocity of the center of mass at the current moment over time and the lateral velocity of the center of mass of the vehicle at the previous moment.

8. The method according to claim 5, wherein the slope at the current moment is used to correct the longitudinal velocity and lateral velocity of the center of mass of the vehicle at the next moment by: Determine a longitudinal velocity change rate and a lateral velocity change rate of the center of mass of the vehicle at a next moment based at least on the slope and the yaw rate at the current moment; Correcting the longitudinal velocity of the center of mass of the vehicle at the next moment based on at least the rate of change of the longitudinal velocity of the center of mass of the vehicle at the next moment using a filtering algorithm; and The center-of-mass lateral velocity of the vehicle at the next moment is corrected based on at least the rate of change of the center-of-mass lateral velocity of the vehicle at the next moment by using an integration algorithm.

9. The method according to claim 6 or 7, wherein the method further comprises: Determine the longitudinal translation correction speed and the lateral translation correction speed of the wheel at the current moment based on vector processing of the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment; and The longitudinal translation correction speed and the lateral translation correction speed of the wheel at the current moment are used to correct the force, longitudinal slip rate and lateral slip rate of the wheel at the next moment.

10. The method according to claim 1, wherein determining the slope at the current moment based on at least the longitudinal velocity of the center of mass and the lateral velocity of the center of mass of the vehicle at the current moment comprises: Determining the longitudinal slope angle at a current moment based at least on the vehicle's center-of-mass lateral velocity, center-of-mass longitudinal velocity, and center-of-mass longitudinal velocity change rate at a current moment; Determining the cross slope angle at the current moment based at least on the center-of-mass lateral velocity, the center-of-mass longitudinal velocity, and the rate of change of the center-of-mass lateral velocity of the vehicle at the current moment; as well as The longitudinal slope angle at the current moment and the transverse slope angle at the current moment are determined as the slope at the current moment.

11. The method according to claim 10, wherein the method further comprises: Processing the longitudinal slope angle at the current moment by using a first low-pass filter; Processing the cross slope angle at the current moment by using a second low-pass filter; The cutoff frequency of the first low-pass filter and the cutoff frequency of the second low-pass filter are adjusted in response to the vehicle being in a transient operating condition or a steady-state operating condition.

12. The method according to claim 11, wherein adjusting the cutoff frequency of the first low-pass filter in response to the vehicle being in a transient operating condition or a steady-state operating condition comprises: Determining that the vehicle is in a transient operating condition or a steady-state operating condition based on one or more of a rate of change of the longitudinal acceleration of the center of mass, a rate of change of the longitudinal velocity of the center of mass, a rate of change of the lateral velocity of the center of mass, and a rate of change of the yaw rate; and A cutoff frequency of the first low pass filter is adjusted in response to a determination that the vehicle is in a transient operating condition or a steady state operating condition.

13. The method according to claim 11, wherein adjusting the cutoff frequency of the second low-pass filter in response to the vehicle being in a transient operating condition or a steady-state operating condition comprises: Based on the rate of change of the center of mass lateral acceleration, the rate of change of the center of mass lateral velocity, and the center of mass longitudinal velocity One or more of the rate of change, the rate of change of the yaw rate, and the vehicle being in a transient state or a steady state; and A cutoff frequency of the second low pass filter is adjusted in response to the vehicle being determined to be in a transient operating condition or a steady state operating condition.

14. A system for determining a vehicle state, characterized in that The system comprises: Memory; a processor coupled to the memory; and A computer program stored on the memory and running on the processor, the running of the computer program causing the method for determining the state of a vehicle according to any one of claims 1 to 13 to be performed.

15. A computer-readable storage medium, characterized in that: The computer storage medium includes instructions that, when executed, perform a method for determining a vehicle state according to any one of claims 1-13.

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