Suspension state determination method and device, electronic equipment and readable storage medium

Abstract

The invention provides a suspension state determination method and device, electronic equipment and a readable storage medium. The method comprises the following steps: acquiring unsprung information of a front axle of a vehicle; according to the axle distance between the front axle and the rear axle, delay information of the front axle and the rear axle passing through the same position is determined, and unsprung information of the rear axle is determined according to the delay information and the unsprung information of the front axle; establishing a sprung motion equation and an unsprung motion equation according to the seven-degree-of-freedom model of the vehicle; establishing a state equation according to the unsprung motion equation, and establishing an observation equation according to the unsprung motion equation, the unsprung information of the front axle and the unsprung information of the rear axle; and performing Kalman filtering processing on the unsprung information of the rear axle according to the state equation and the observation equation, and outputting the optimized unsprung information of the rear axle. The delay of the front axle and the rear axle passing through the same position can be determined by using the axle distance between the front axle and the rear axle, so that the rear axle unsprung information is estimated through the front axle unsprung information, the data acquisition process of the rear axle unsprung information is simplified, and the sensor cost of the rear axle is saved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of vehicle engineering technology, and in particular, to a suspension state determination method, device, electronic device, and readable storage medium. Background Art

[0002] With the rapid development of vehicle control technology, people have higher and higher requirements for vehicle handling stability and ride comfort. When a vehicle is driving on an impact road or a continuously bumpy road, the impact caused by the change in road height will cause discomfort to passengers, affecting the ride comfort of the vehicle and even affecting the vehicle's handling stability and driving safety. Therefore, in order to improve the safety and comfort of vehicle driving, it is very important to accurately estimate the suspension state of the vehicle while driving.

[0003] For suspension state estimation, sensors such as acceleration sensors or height sensors need to be arranged under the front and rear axle springs to obtain suspension motion data.

[0004] However, since directly installing sensors requires physical modifications to the vehicle chassis or suspension, obtaining the status of the entire vehicle through sensors increases manufacturing costs and may also lead to the complication of the vehicle structure and increase additional maintenance costs. Summary of the invention

[0005] In view of the above problems, embodiments of the present invention are proposed to provide a suspension state determination method, device, electronic device and readable storage medium that overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, an embodiment of the present application discloses a method for determining a suspension state, the method comprising:

[0007] Obtain unsprung information of the vehicle's front axle;

[0008] Determining delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle, and determining unsprung information of the rear axle according to the delay information and unsprung information of the front axle;

[0009] The sprung motion equation and the unsprung motion equation are established according to the seven-degree-of-freedom model of the vehicle;

[0010] Establishing a state equation according to the unsprung motion equation, and establishing an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle;

[0011] Kalman filtering is performed on the unsprung information of the rear axle according to the state equation and the observation equation, and optimized unsprung information of the rear axle is output.

[0012] Optionally, the delay information includes a delay duration, and the determining, based on the wheelbase between the front axle and the rear axle, the delay information of the front axle and the rear axle passing through the same position includes:

[0013] Determining a delay time according to the vehicle speed and the wheelbase;

[0014] The determining the unsprung information of the rear axle according to the delay information and the unsprung information of the front axle comprises:

[0015] The unsprung information of the front axle at the first moment is used as the unsprung information of the rear axle at the second moment; wherein, the first moment is before the second moment, and the time difference between the first moment and the second moment is the delay time.

[0016] Optionally, the delay information includes a delay distance, and determining the delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle includes:

[0017] Determine, according to the wheelbase between the front axle and the rear axle, a delay distance for the front axle and the rear axle to pass the same position; the delay distance represents a distance difference between a first travel distance when the front axle reaches the position and a second travel distance when the rear axle reaches the position;

[0018] The determining the unsprung information of the rear axle according to the delay information and the unsprung information of the front axle comprises:

[0019] determining a target driving distance based on the second driving distance and the delay distance;

[0020] A first running distance that is the same as the target running distance is determined, and unsprung information of the front axle at the first running distance is used as unsprung information of the rear axle at the second running distance.

[0021] Optionally, establishing the sprung motion equation and the unsprung motion equation according to the seven-degree-of-freedom model of the vehicle includes:

[0022] According to the seven-degree-of-freedom model of the vehicle, the sprung motion equation and the unsprung motion equation are established in combination with the vehicle parameters;

[0023] Among them, the vehicle parameters include: sprung mass, vertical acceleration of center of mass, suspension damping, suspension stiffness, unsprung displacement, sprung displacement, suspension control force, pitch moment of inertia, pitch angular acceleration, roll moment of inertia, roll angular acceleration, unsprung acceleration, distance from center of mass to front axle, distance from center of mass to rear axle and at least one of tire stiffness; the sprung motion equations include: vertical motion equation at the center of mass of the vehicle body, pitch motion equation of the vehicle body and roll motion equation of the vehicle body; the unsprung motion equations include: four unsprung mass motion equations.

[0024] Optionally, establishing a state equation according to the unsprung motion equation comprises:

[0025] The unsprung velocities and unsprung displacements of the left front, right front, left rear and right rear are selected as state quantities, the sprung velocities, sprung displacements and suspension control forces of the left front, right front, left rear and right rear are selected as control quantities, and the road surface excitations at the four tires are selected as state noise. The state equation is established in combination with the unsprung motion equation.

[0026] Optionally, establishing an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle includes:

[0027] The center of mass vertical acceleration, pitch angular acceleration, roll angular acceleration, the unsprung information of the front axle obtained by the sensor, and the unsprung information of the rear axle obtained according to the delay information are selected as the observed quantities to establish the observation equation.

[0028] Optionally, the unsprung information of the front axle includes front unsprung speed and front unsprung acceleration;

[0029] The obtaining of unsprung information of the front axle of the vehicle includes:

[0030] Acquire the front spring under-acceleration collected by an acceleration sensor installed under the front spring, and obtain the front spring under-speed by integrating the front spring under-acceleration; or

[0031] Acquire height information collected by a height sensor installed on the front suspension, determine the speed and acceleration of the front suspension according to the height information, acquire the speed and acceleration of the front tower top collected by a tower top acceleration sensor, and determine the front unsprung speed and the front unsprung acceleration according to the speed and acceleration of the front suspension and the speed and acceleration of the front tower top.

[0032] In a second aspect, an embodiment of the present application discloses a suspension state determination device, the device comprising:

[0033] An acquisition module, used for acquiring unsprung information of a front axle of a vehicle;

[0034] an estimation module, configured to determine delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle, and determine unsprung information of the rear axle according to the delay information and unsprung information of the front axle;

[0035] A first building block is used to establish a sprung motion equation and an unsprung motion equation according to a seven-degree-of-freedom model of the vehicle;

[0036] A second building block is used to establish a state equation according to the unsprung motion equation, and to establish an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle;

[0037] The correction module is used to perform Kalman filtering on the unsprung information of the rear axle according to the state equation and the observation equation, and output optimized unsprung information of the rear axle.

[0038] In a third aspect, an embodiment of the present application further discloses an electronic device, comprising a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the suspension state determination method described in the first aspect are implemented.

[0039] In a fourth aspect, an embodiment of the present application further discloses a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the suspension state determination method described in the first aspect are implemented.

[0040] In an embodiment of the present application, unsprung information of the front axle of the vehicle is obtained; based on the wheelbase between the front axle and the rear axle, delay information of the front axle and the rear axle passing through the same position is determined, and based on the delay information and the unsprung information of the front axle, the unsprung information of the rear axle is determined; sprung motion equations and unsprung motion equations are established based on a seven-degree-of-freedom model of the vehicle; a state equation is established based on the unsprung motion equation, and an observation equation is established based on the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle; Kalman filtering is performed on the unsprung information of the rear axle based on the state equation and the observation equation, and optimized unsprung information of the rear axle is output. That is, after obtaining the unsprung information of the front axle, the method of the present application can determine the delay of the front axle and the rear axle passing the same position by using the wheelbase between the front axle and the rear axle, thereby estimating the unsprung information of the rear axle by using the front unsprung information, thereby simplifying the data acquisition process of obtaining the unsprung information of the rear axle, and eliminating the need to install sensors under the rear axle spring to determine the rear unsprung information, thereby saving the sensor cost of the rear axle. Furthermore, in order to make the unsprung information of the rear axle determined according to the delay information more accurate, the present application also optimizes the acquired unsprung information of the rear axle based on the vehicle's seven-degree-of-freedom model and Kalman filtering. The unsprung information of the rear axle determined according to the delay information is more accurate, thereby improving the estimation accuracy and stability of the motion state of the rear unsprung axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of the steps of a suspension state determination method provided by an embodiment of the present invention;

[0042] Figure 2 It is a schematic diagram of a seven-degree-of-freedom model provided by an embodiment of the present invention;

[0043] Figure 3 is a block diagram of a suspension state determination device provided by an embodiment of the present invention;

[0044] Figure 4is a block diagram of an electronic device provided by an embodiment of the present invention;

[0045] Figure 5 is a block diagram of another electronic device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0046] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0047] refer to Figure 1 , which shows a suspension state determination method provided by an embodiment of the present application, the method comprising:

[0048] Step 101, obtaining unsprung information of the front axle of the vehicle.

[0049] In an embodiment of the present invention, the unsprung information of the front axle of the vehicle can be directly collected and acquired by a sensor disposed under the front spring. The unsprung information of the front axle of the vehicle may include information such as the front unsprung speed and the front unsprung acceleration. Based on the principle that the rear wheels of the vehicle will inevitably press over the road surface that the front wheels have already pressed when the vehicle is driving, the present application can simply determine the unsprung information of the rear axle based on the collected unsprung information of the front axle, thereby realizing the determination of the suspension state.

[0050] Optionally, step 101 includes:

[0051] Sub-step 1011, obtaining the front unsprung acceleration collected by the acceleration sensor installed under the front spring, and obtaining the front unsprung velocity by integrating the front unsprung acceleration.

[0052] In an embodiment of the present invention, the unsprung information of the front axle can be directly collected by a sensor installed under the front axle spring. For example, an acceleration sensor is installed under the front spring to directly collect the acceleration under the front spring. The acceleration is the rate of change of velocity with time. Therefore, the front unsprung velocity can be obtained by integrating the acceleration.

[0053] Optionally, step 101 includes:

[0054] Sub-step 1012, obtaining height information collected by a height sensor installed on the front suspension, determining the speed and acceleration of the front suspension based on the height information, and obtaining the speed and acceleration of the front tower top collected by the tower top acceleration sensor, and determining the front unsprung speed and the front unsprung acceleration based on the speed and acceleration of the front suspension and the speed and acceleration of the front tower top.

[0055] In the embodiment of the present invention, for sub-steps 1012 to 1041, the unsprung information of the front axle can also be obtained by installing a height sensor between the suspensions to obtain the height information of the front suspension. According to the differential and quadratic differential of the height, the speed and acceleration of the front suspension can be obtained respectively. Furthermore, the speed and acceleration of the tower top can be obtained by sensors installed on the springs, including but not limited to an inertial measurement unit (IMU) or four tower top acceleration sensors, and the speed and acceleration of the front tower top are subtracted from the speed and acceleration of the front suspension to obtain the unsprung speed and unsprung acceleration.

[0056] Step 102, determining the delay information of the front axle and the rear axle passing the same position according to the wheelbase between the front axle and the rear axle, and determining the unsprung information of the rear axle according to the delay information and the unsprung information of the front axle.

[0057] In the embodiment of the present invention, due to the wheelbase between the front axle and the rear axle, there is a delay between the front axle and the rear axle when passing the same position. Therefore, the unsprung information (speed, acceleration) of the front axle can be delayed to serve as the unsprung information of the rear axle, thereby eliminating the device cost and maintenance cost caused by installing sensors on the rear axle.

[0058] Optionally, the delay information includes a delay duration, and step 102 includes:

[0059] Sub-step 1021, determining a delay time according to the vehicle speed and the wheelbase;

[0060] Sub-step 1022, using the unsprung information of the front axle at the first moment as the unsprung information of the rear axle at the second moment; wherein the first moment is before the second moment, and the time difference between the first moment and the second moment is the delay time.

[0061] In the embodiment of the present invention, for sub-steps 1021 and 1022, the method for determining the unsprung information of the rear axle according to the unsprung information of the front axle may be: by determining the delay time length, the delay time length t for the rear axle to reach the same position as the front axle may be determined according to the obtained vehicle speed and the wheelbase between the front axle and the rear axle, and the unsprung information of the rear axle may be indirectly determined according to the determined delay time length t, that is, the unsprung information of the rear axle at the current moment is the unsprung information of the front axle t time ago. That is, by determining the delay time length, the unsprung information of the rear axle may be estimated from the unsprung information of the front axle.

[0062] Optionally, the delay information includes a delay distance, and step 102 includes:

[0063] Sub-step 1023, determining a delay distance for the front axle and the rear axle to pass the same position according to the wheelbase between the front axle and the rear axle; the delay distance represents a distance difference between a first driving distance when the front axle reaches the position and a second driving distance when the rear axle reaches the position;

[0064] Sub-step 1024, determining a target driving distance based on the second driving distance and the delay distance;

[0065] Sub-step 1025, determining a first driving distance that is the same as the target driving distance, and using the unsprung information of the front axle at the first driving distance as the unsprung information of the rear axle at the second driving distance.

[0066] In the embodiment of the present invention, for sub-step 1023 and sub-step 1024, the method for determining the unsprung information of the rear axle based on the unsprung information of the front axle can also be: by delaying the distance, after obtaining the vehicle speed, the first driving distance under the front spring and the second driving distance under the rear spring can be respectively obtained by integrating the vehicle speed.

[0067] For any position, the front axle needs to travel a specific first driving distance to reach the position, and the motion information under the front spring at the first driving distance is saved. When the rear spring reaches the position after a second driving distance, the distance difference between the first driving distance and the second driving distance, i.e., the delay distance, is fixed, and the distance difference is the wheelbase. For example, there is a target position in front of the vehicle, and the distance from the target position to the front axle is x, then the distance from the target position to the rear axle is x plus the wheelbase.

[0068] Due to the existence of the delay distance, when the rear axle reaches the position after traveling the second driving distance, the front axle actually only needs to travel a distance equal to the second driving distance minus the delay distance (wheelbase), that is, the target driving distance, to reach the position.

[0069] Then, for any position corresponding to the second driving distance of the rear axle, the corresponding target driving distance can be obtained by subtracting the delay distance from the second driving distance. If the position reached by the front axle after the first driving distance equal to the target driving distance is the same as the position reached by the rear axle after the second driving distance, the unsprung information of the front axle at the position can be used as the unsprung information of the rear axle at the position.

[0070] The above method for determining the unsprung information of the rear axle is determined by the same delay principle but using different implementation paths. The unsprung motion information of the rear axle can be reflected to a certain extent by determining the delay, but due to the different stiffness and damping of the front and rear axles, as well as the unevenness of the road surface, the unsprung information of the rear axle obtained directly by delay may have the problem of insufficient accuracy. Therefore, the present application further optimizes the obtained unsprung information of the rear axle by Kalman filtering, and improves the accuracy and stability of the unsprung information of the rear axle obtained based on the delay information.

[0071] Step 103: establishing a sprung motion equation and an unsprung motion equation according to the seven-degree-of-freedom model of the vehicle.

[0072] In an embodiment of the present invention, the seven-degree-of-freedom model of the vehicle is used to describe the dynamic motion characteristics of the vehicle, including lateral displacement, longitudinal movement, yaw motion and rotational motion of the four wheels, a total of seven degrees of freedom. This model can more accurately describe the motion characteristics of the vehicle.

[0073] The main components of the seven-degree-of-freedom vehicle model include:

[0074] Lateral displacement: the movement of the vehicle in the horizontal direction; Longitudinal displacement: the movement of the vehicle in a straight line; Yaw: the rotation of the vehicle around its vertical axis; Rotational motion of the four wheels: the independent rotation of each wheel.

[0075] By constructing a seven-degree-of-freedom vehicle model, the dynamic behavior of the vehicle can be predicted and analyzed more accurately, which is of great significance for improving the vehicle's handling, safety and comfort, allowing the vehicle to better adapt to various complex driving environments and conditions.

[0076] refer to Figure 2 , Figure 2 A seven-degree-of-freedom model provided by an embodiment of the present application is shown, and the meanings of the parameters in the figure are as follows: m b is the sprung mass, C Si is the suspension damping (C SA , C SB , C SC , C SD are the suspension damping of the left front, right front, left rear and right rear), K Si is the suspension stiffness (ks A ,ks B ,ks C ,ks D are the suspension heights of the left front, right front, left rear, and right rear), Z i is the unsprung displacement (z A 、z B 、z C 、z Dare the unsprung displacements of the left front, right front, left rear, and right rear), Z bi is the sprung displacement (z bA 、z bB 、z bC 、z bD are the sprung displacements of the left front, right front, left rear, and right rear), m i is the unsprung acceleration (m1, m2, m3, and m4 are the unsprung accelerations of the left front, right front, left rear, and right rear, respectively), α is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, kt A , kt B , kt C , kt D are the four tire stiffnesses of the left front, right front, left rear, and right rear, respectively, θ b is the vehicle body pitch angle, is the body roll angle, z b is the vertical displacement of the center of mass of the vehicle body, q A ,q B ,q C ,q D The road surface excitations are at the four tires: left front, right front, left rear, and right rear.

[0077] Optionally, step 103 includes:

[0078] Sub-step 1031, establishing a sprung motion equation and an unsprung motion equation according to a seven-degree-of-freedom model of the vehicle and combining vehicle parameters;

[0079] Among them, the vehicle parameters include: sprung mass, vertical acceleration of center of mass, suspension damping, suspension stiffness, unsprung displacement, sprung displacement, suspension control force, pitch moment of inertia, pitch angular acceleration, roll moment of inertia, roll angular acceleration, unsprung acceleration, distance from center of mass to front axle, distance from center of mass to rear axle and at least one of tire stiffness; the sprung motion equations include: vertical motion equation at the center of mass of the vehicle body, pitch motion equation of the vehicle body and roll motion equation of the vehicle body; the unsprung motion equations include: four unsprung mass motion equations.

[0080] In the embodiment of the present invention, according to the above-mentioned seven-degree-of-freedom model, the sprung motion equation and the unsprung motion equation can be established, wherein the sprung motion equation includes the vertical motion equation at the center of mass of the vehicle body, the vehicle body pitch motion equation and the vehicle body roll motion equation, as follows:

[0081]

[0082] in, is the vertical acceleration of the center of mass, F iis the suspension control force (where i = 1, 2, 3, 4, corresponding to the suspension control forces of the left front, right front, left rear, and right rear, respectively), I p is the pitch moment of inertia, is the pitch angular acceleration, I r is the roll moment of inertia, is the roll angular acceleration, Z wA , Z wB , Z wC , Z wD is the displacement of the center of mass of the four front, rear, left and right wheels, Bf and Br are the front and rear axle track widths, and the other parameters can be referred to Figure 2 Interpretation of the parameters in the seven-degree-of-freedom model.

[0083] The equations of motion for the unsprung mass include the four equations of motion for the unsprung mass, which include the following four equations:

[0084]

[0085] In the above formula, m wA 、m wB 、m wC 、m wD represents the left front unsprung mass, right front unsprung mass, left rear unsprung mass and right rear unsprung mass, Z gA , Z gB , Z gC , Z gD Indicates the road surface excitation at the front, rear, left and right tires. For other parameter definitions, please refer to Figure 2 The interpretation of the parameters in the seven-degree-of-freedom model and the related parameters of the sprung motion equation will not be repeated here.

[0086] Step 104, establishing a state equation according to the unsprung motion equation, and establishing an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle.

[0087] Optionally, step 104 includes:

[0088] In sub-step 1041, the unsprung velocities and unsprung displacements of the left front, right front, left rear and right rear are selected as state quantities, the sprung velocities, sprung displacements and suspension control forces of the left front, right front, left rear and right rear are selected as control quantities, and the road surface excitations at the four tires are selected as state noise, and the state equation is established in combination with the unsprung motion equation.

[0089] In the embodiment of the present invention, the state equation established according to the unsprung motion equation may be:

[0090]

[0091] Among them, the state quantity X is:

[0092]

[0093] That is, the unsprung speed and unsprung displacement of the left front, right front, left rear and right rear are selected as the state quantities, and the control quantity U is:

[0094]

[0095] That is, the sprung speed, sprung displacement and suspension control force of the left front, right front, left rear and right rear are selected as the control variables, W i (i=1, 2, 3, 4) is the state noise. In Kalman filtering, the change of state quantity is described by the state equation. The control quantity is the external input acting on the system, which can affect the change of the system state. In Kalman filtering, the state noise can reflect the uncertainty in the system state equation.

[0096] Optionally, step 104 includes:

[0097] In sub-step 1042, the center of mass vertical acceleration, the pitch angular acceleration, the roll angular acceleration, the unsprung information of the front axle obtained by the sensor, and the unsprung information of the rear axle obtained according to the delay information are selected as observation quantities to establish the observation equation.

[0098] In the embodiment of the present invention, the observation equation established according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle may be:

[0099]

[0100] in, is the speed under the front spring, which is directly collected by the sensor (integral of the acceleration sensor under the front spring or differential of the height sensor). is the rear unsprung speed obtained by the above-mentioned delayed information method. For the interpretation of other parameters, please refer to the above-mentioned embodiment.

[0101] Among them, the observation quantity Y is:

[0102]

[0103] That is, the vertical acceleration of the center of mass, the pitch angular acceleration, the roll angular acceleration, the unsprung information of the front axle obtained by the sensor, and the unsprung information of the rear axle obtained according to the delay information are used as observation quantities to establish the observation equation.

[0104] Step 105 , performing Kalman filtering on the unsprung information of the rear axle according to the state equation and the observation equation, and outputting optimized unsprung information of the rear axle.

[0105] In the embodiment of the present invention, the unsprung information of the rear axle is processed by Kalman filtering according to the state equation and the observation equation, and the optimized unsprung information of the rear axle can be output. The state quantity can be obtained by performing Kalman filtering according to the above equation:

[0106]

[0107] That is, the optimized unsprung speed and unsprung displacement.

[0108] Specifically, Kalman filtering is a recursive estimation, that is, as long as the estimated value of the state at the previous moment and the observed value of the current state are known, the estimated value of the current state can be calculated, so there is no need to record historical information of observation or estimation. Kalman filtering is mainly divided into two parts: prediction and update. It is necessary to construct the state equation and observation equation of the system, and the initial state of the system is known. In the prediction stage, the filter uses the estimate of the previous state to make an estimate of the current state. In the update stage, the filter uses the observed value of the current state to optimize the predicted value obtained in the prediction stage to obtain a more accurate new estimated value. Combined with the above analysis, in this application, the unsprung information of the rear axle is obtained through the unsprung information of the front axle, and the data collected by the front unsprung sensor is combined as the observation data to optimize the unsprung information of the rear axle, that is, the optimal estimated value at time k-1 is used to predict the state quantity at time k; the state quantity at time k is corrected according to the observed value at time k to obtain the optimal estimated value at time k.

[0109] Furthermore, in the Kalman filtering process, according to the constructed state matrix and observation matrix, the Kalman gain K can be solved by adjusting the values ​​of Q (process noise covariance) and R (measurement noise covariance), where the values ​​of Q and R are obtained according to the actual vehicle calibration. The Kalman gain K is used to fuse the data collected by different sensors and the rear unsprung motion signal obtained by delaying the information, thereby improving the estimation accuracy of the rear unsprung motion state. Different combinations of Q and R values ​​can be considered and adjusted according to the characteristics of specific vehicles and road conditions to obtain the best Kalman gain K, thereby obtaining more accurate rear unsprung motion information.

[0110] In addition, different Q value combinations and R methods can be dynamically adjusted through the root mean square of acceleration directly collected by the sensor under the front spring. The adjustment method is to multiply the Q and R values ​​by a gain q and r respectively. The larger the root mean square, the larger q and the smaller r; the smaller the root mean square, the smaller q and the larger r. The mapping relationship between the root mean square and q, r is confirmed based on the actual vehicle calibration.

[0111] The method of determining the unsprung information of the rear axle through the unsprung information of the front axle can achieve the following beneficial effects: Cost saving and simplified design: By estimating the motion state of the rear unsprung without installing the rear unsprung sensor, the cost and complexity of the system are significantly reduced. The cost of sensor installation and the cost of vehicle structure modification are avoided, simplifying the design and manufacturing process of the system. Improve system reliability and stability: The Kalman filter algorithm is introduced to improve the estimation accuracy and stability of the motion state of the rear unsprung by optimizing the data fusion and processing process. This process not only enables the system to respond to vehicle dynamic changes more accurately, but also reduces the problem of data instability caused by sensor failure or adverse environmental conditions. Improve monitoring and control accuracy: By more accurately estimating the motion state of the rear unsprung, the technical solution can improve the accuracy and efficiency of the vehicle dynamic performance monitoring and control system. This is of great significance to driving safety, comfort and long-term maintenance of the vehicle suspension system.

[0112] In addition, in addition to the method of combining the delay information with the Kalman filter to obtain the rear unsprung information involved in the above-mentioned application, it can also be implemented through other filtering algorithms: for example, extended Kalman filtering (EKF) or data fusion methods based on deep learning to achieve similar multi-parameter estimation. And use model-based predictive control (MPC) or recursive least squares (RLS) algorithms to achieve accurate estimation of more complex states of the dynamic suspension system. Regarding the vehicle model, it can also be designed based on other vehicle dynamic models: that is, different vehicle dynamic models or mathematical modeling methods of the suspension system are used to estimate the motion state of the rear unsprung. For example: the new vehicle dynamic model can take into account more complex parameters and environmental conditions, such as road conditions, load changes, etc., to achieve a more accurate estimation of the motion state of the rear unsprung, and the embodiments of the present application are not limited here.

[0113] This application uses a method combining delayed information and Kalman filtering to effectively estimate the motion state of the rear unsprung by using the motion information of the front unsprung and the sprung without installing a rear unsprung sensor. This method can not only significantly reduce the cost of the system, but also improve the practicality of the system, and is suitable for a variety of vehicle dynamic performance monitoring and control application scenarios.

[0114] In summary, in the embodiment of the present application, the unsprung information of the front axle of the vehicle is obtained; based on the wheelbase between the front axle and the rear axle, the delay information of the front axle and the rear axle passing the same position is determined, and the unsprung information of the rear axle is determined based on the delay information and the unsprung information of the front axle; the sprung motion equation and the unsprung motion equation are established according to the seven-degree-of-freedom model of the vehicle; the state equation is established according to the unsprung motion equation, and the observation equation is established according to the sprung motion equation, the unsprung information of the front axle and the unsprung information of the rear axle; the unsprung information of the rear axle is subjected to Kalman filtering according to the state equation and the observation equation, and the optimized unsprung information of the rear axle is output. That is, after obtaining the unsprung information of the front axle, the method of the present application can determine the delay of the front axle and the rear axle passing the same position by using the wheelbase between the front axle and the rear axle, thereby estimating the unsprung information of the rear axle by using the front unsprung information, thereby simplifying the data acquisition process of obtaining the unsprung information of the rear axle, and eliminating the need to install sensors under the rear axle spring to determine the rear unsprung information, thereby saving the sensor cost of the rear axle. Furthermore, in order to make the unsprung information of the rear axle determined according to the delay information more accurate, the present application also optimizes the acquired unsprung information of the rear axle based on the vehicle's seven-degree-of-freedom model and Kalman filtering. The unsprung information of the rear axle determined according to the delay information is more accurate, thereby improving the estimation accuracy and stability of the motion state of the rear unsprung axle.

[0115] refer to Figure 3 , which shows a suspension state determination device 20 provided in an embodiment of the present application, comprising:

[0116] An acquisition module 201 is used to acquire unsprung information of a front axle of a vehicle;

[0117] an estimation module 202, configured to determine delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle, and determine unsprung information of the rear axle according to the delay information and unsprung information of the front axle;

[0118] A first building module 203 is used to establish a sprung motion equation and an unsprung motion equation according to a seven-degree-of-freedom model of the vehicle;

[0119] A second building module 204 is used to establish a state equation according to the unsprung motion equation, and to establish an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle;

[0120] The correction module 205 is used to perform Kalman filtering on the unsprung information of the rear axle according to the state equation and the observation equation, and output optimized unsprung information of the rear axle.

[0121] Optionally, the delay information includes a delay duration, and the estimation module includes:

[0122] A first determination submodule, used to determine a delay time according to a vehicle speed and the wheelbase of the vehicle;

[0123] The first estimation submodule is used to use the unsprung information of the front axle at a first moment as the unsprung information of the rear axle at a second moment; wherein the first moment is before the second moment, and the time difference between the first moment and the second moment is the delay time.

[0124] Optionally, the delay information includes a delay distance, and the estimation module includes:

[0125] A second determination submodule is used to determine a delay distance for the front axle and the rear axle to pass the same position according to the wheelbase between the front axle and the rear axle; the delay distance represents a distance difference between a first driving distance when the front axle reaches the position and a second driving distance when the rear axle reaches the position;

[0126] a corresponding distance submodule, configured to determine a target driving distance based on the second driving distance and the delay distance;

[0127] The second estimation submodule is used to determine a first driving distance that is the same as the target driving distance, and use the unsprung information of the front axle at the first driving distance as the unsprung information of the rear axle at the second driving distance.

[0128] Optionally, the first building block includes:

[0129] The first construction submodule is used to establish the sprung motion equation and the unsprung motion equation according to the seven-degree-of-freedom model of the vehicle and in combination with the vehicle parameters;

[0130] Among them, the vehicle parameters include: sprung mass, vertical acceleration of center of mass, suspension damping, suspension stiffness, unsprung displacement, sprung displacement, suspension control force, pitch moment of inertia, pitch angular acceleration, roll moment of inertia, roll angular acceleration, unsprung acceleration, distance from center of mass to front axle, distance from center of mass to rear axle and at least one of tire stiffness; the sprung motion equations include: vertical motion equation at the center of mass of the vehicle body, pitch motion equation of the vehicle body and roll motion equation of the vehicle body; the unsprung motion equations include: four unsprung mass motion equations.

[0131] Optionally, the second building block includes:

[0132] The second construction submodule is used to select the unsprung velocities and unsprung displacements of the left front, right front, left rear and right rear as state quantities, the sprung velocities, sprung displacements and suspension control forces of the left front, right front, left rear and right rear as control quantities, and the road surface excitations at the four tires as state noise, and establish a state equation in combination with the unsprung motion equation.

[0133] Optionally, the second building block includes:

[0134] The third construction submodule is used to select the center of mass vertical acceleration, pitch angular acceleration, roll angular acceleration, unsprung information of the front axle obtained by sensor measurement, and unsprung information of the rear axle obtained according to delay information as observation quantities to establish the observation equation.

[0135] Optionally, the unsprung information of the front axle includes front unsprung speed and front unsprung acceleration;

[0136] The acquisition module comprises:

[0137] The first acquisition submodule is used to acquire the front spring under-acceleration collected by the acceleration sensor installed under the front spring, and obtain the front spring under-speed by integrating the front spring under-acceleration;

[0138] The second acquisition submodule is used to acquire height information collected by a height sensor installed on the front suspension, determine the speed and acceleration of the front suspension according to the height information, and acquire the speed and acceleration of the front tower top collected by the tower top acceleration sensor, and determine the front unsprung speed and the front unsprung acceleration according to the speed and acceleration of the front suspension and the speed and acceleration of the front tower top.

[0139] In summary, in the embodiment of the present application, the unsprung information of the front axle of the vehicle is obtained; based on the wheelbase between the front axle and the rear axle, the delay information of the front axle and the rear axle passing the same position is determined, and the unsprung information of the rear axle is determined based on the delay information and the unsprung information of the front axle; the sprung motion equation and the unsprung motion equation are established according to the seven-degree-of-freedom model of the vehicle; the state equation is established according to the unsprung motion equation, and the observation equation is established according to the sprung motion equation, the unsprung information of the front axle and the unsprung information of the rear axle; the unsprung information of the rear axle is subjected to Kalman filtering according to the state equation and the observation equation, and the optimized unsprung information of the rear axle is output. That is, after obtaining the unsprung information of the front axle, the method of the present application can determine the delay of the front axle and the rear axle passing the same position by using the wheelbase between the front axle and the rear axle, thereby estimating the unsprung information of the rear axle by using the front unsprung information, thereby simplifying the data acquisition process of obtaining the unsprung information of the rear axle, and eliminating the need to install sensors under the rear axle spring to determine the rear unsprung information, thereby saving the sensor cost of the rear axle. Furthermore, in order to make the unsprung information of the rear axle determined according to the delay information more accurate, the present application also optimizes the acquired unsprung information of the rear axle based on the vehicle's seven-degree-of-freedom model and Kalman filtering. The unsprung information of the rear axle determined according to the delay information is more accurate, thereby improving the estimation accuracy and stability of the motion state of the rear unsprung axle.

[0140] Figure 4A block diagram of an electronic device 600 is shown according to an exemplary embodiment. For example, the electronic device 600 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0141] Reference Figure 4 , the sub-device 600 may include one or more of the following components: a processing component 602 , a memory 604 , a power component 606 , a multimedia component 608 , an audio component 610 , an input / output (I / O) interface 612 , a sensor component 614 , and a communication component 616 .

[0142] The processing component 602 generally controls the overall operation of the electronic device 600, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 602 may include one or more processors 620 to execute instructions to complete all or part of the steps of the above-mentioned method. In addition, the processing component 602 may include one or more modules to facilitate the interaction between the processing component 602 and other components. For example, the processing component 602 may include a multimedia module to facilitate the interaction between the multimedia component 608 and the processing component 602.

[0143] The memory 604 is used to store various types of data to support the operation of the electronic device 600. Examples of such data include instructions for any application or method operating on the electronic device 600, contact data, phone book data, messages, pictures, multimedia, etc. The memory 604 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0144] The power supply component 606 provides power to the various components of the electronic device 600. The power supply component 606 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the electronic device 600.

[0145] The multimedia component 608 includes a screen that provides an output interface between the electronic device 600 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 608 includes a front camera and / or a rear camera. When the electronic device 600 is in an operating mode, such as a shooting mode or a multimedia mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and the rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0146] The audio component 610 is used to output and / or input audio signals. For example, the audio component 610 includes a microphone (MIC), and when the electronic device 600 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode, the microphone is used to receive an external audio signal. The received audio signal can be further stored in the memory 604 or sent via the communication component 616. In some embodiments, the audio component 610 also includes a speaker for outputting audio signals.

[0147] I / O interface 612 provides an interface between processing component 602 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include but are not limited to: a home button, a volume button, a start button, and a lock button.

[0148] The sensor assembly 614 includes one or more sensors for providing various aspects of status assessment for the electronic device 600. For example, the sensor assembly 614 can detect the open / closed state of the electronic device 600, the relative positioning of the components, such as the display and keypad of the electronic device 600, and the sensor assembly 614 can also detect the position change of the electronic device 600 or a component of the electronic device 600, the presence or absence of contact between the user and the electronic device 600, the orientation or acceleration / deceleration of the electronic device 600, and the temperature change of the electronic device 600. The sensor assembly 614 may include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 614 may also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 614 may also include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0149] The communication component 616 is used to facilitate wired or wireless communication between the electronic device 600 and other devices. The electronic device 600 can access a wireless network based on a communication standard, such as WiFi, a carrier network (such as 2G, 3G, 4G or 5G), or a combination thereof. In an exemplary embodiment, the communication component 616 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 616 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0150] In an exemplary embodiment, the electronic device 600 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components to implement the suspension state determination method provided in the embodiments of the present application.

[0151] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 604 including instructions, and the instructions can be executed by a processor 620 of an electronic device 600 to perform the above method. For example, the non-transitory storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a tape, a floppy disk, an optical suspension state determination device, etc.

[0152] Figure 5 A block diagram of an electronic device 700 is shown according to an exemplary embodiment. For example, the electronic device 700 can be provided as a server. Figure 5 The electronic device 700 includes a processing component 722, which further includes one or more processors, and a memory resource represented by a memory 732 for storing instructions executable by the processing component 722, such as an application. The application stored in the memory 732 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 722 is configured to execute instructions to perform a suspension state determination method provided in an embodiment of the present application.

[0153] The electronic device 700 may also include a power supply component 726 configured to perform power management of the electronic device 700, a wired or wireless network interface 750 configured to connect the electronic device 700 to a network, and an input / output (I / O) interface 758. The electronic device 700 may operate based on an operating system stored in the memory 732, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™ or the like.

[0154] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0155] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for determining a suspension state, characterized in that: The method comprises: Obtain unsprung information of the vehicle's front axle; Determining delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle, and determining unsprung information of the rear axle according to the delay information and unsprung information of the front axle; The sprung motion equation and the unsprung motion equation are established according to the seven-degree-of-freedom model of the vehicle; Establishing a state equation according to the unsprung motion equation, and establishing an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle; Kalman filtering is performed on the unsprung information of the rear axle according to the state equation and the observation equation, and optimized unsprung information of the rear axle is output.

2. The method according to claim 1, characterized in that The delay information includes the delay duration; The step of determining the delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle includes: Determining a delay time according to the vehicle speed and the wheelbase; The determining the unsprung information of the rear axle according to the delay information and the unsprung information of the front axle comprises: The unsprung information of the front axle at the first moment is used as the unsprung information of the rear axle at the second moment; wherein, the first moment is before the second moment, and the time difference between the first moment and the second moment is the delay time.

3. The method according to claim 1, characterized in that The delay information includes a delay distance; The step of determining the delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle includes: Determine, according to the wheelbase between the front axle and the rear axle, a delay distance for the front axle and the rear axle to pass the same position; the delay distance represents a distance difference between a first travel distance when the front axle reaches the position and a second travel distance when the rear axle reaches the position; The determining the unsprung information of the rear axle according to the delay information and the unsprung information of the front axle comprises: determining a target driving distance based on the second driving distance and the delay distance; A first running distance that is the same as the target running distance is determined, and unsprung information of the front axle at the first running distance is used as unsprung information of the rear axle at the second running distance.

4. The method according to claim 1, characterized in that: The method of establishing the sprung motion equation and the unsprung motion equation according to the seven-degree-of-freedom model of the vehicle includes: According to the seven-degree-of-freedom model of the vehicle, the sprung motion equation and the unsprung motion equation are established in combination with the vehicle parameters; Among them, the vehicle parameters include: sprung mass, vertical acceleration of center of mass, suspension damping, suspension stiffness, unsprung displacement, sprung displacement, suspension control force, pitch moment of inertia, pitch angular acceleration, roll moment of inertia, roll angular acceleration, unsprung acceleration, distance from center of mass to front axle, distance from center of mass to rear axle and at least one of tire stiffness; the sprung motion equations include: vertical motion equation at the center of mass of the vehicle body, pitch motion equation of the vehicle body and roll motion equation of the vehicle body; the unsprung motion equations include: four unsprung mass motion equations.

5. The method according to claim 4, characterized in that The establishing of the state equation according to the unsprung motion equation comprises: The unsprung velocities and unsprung displacements of the left front, right front, left rear and right rear are selected as state quantities, the sprung velocities, sprung displacements and suspension control forces of the left front, right front, left rear and right rear are selected as control quantities, and the road surface excitations at the four tires are selected as state noise. The state equation is established in combination with the unsprung motion equation.

6. The method according to claim 4, characterized in that The establishing of the observation equation according to the sprung motion equation, the unsprung information of the front axle and the unsprung information of the rear axle comprises: The center of mass vertical acceleration, pitch angular acceleration, roll angular acceleration, the unsprung information of the front axle obtained by the sensor, and the unsprung information of the rear axle obtained according to the delay information are selected as the observed quantities to establish the observation equation.

7. The method according to claim 1, characterized in that The unsprung information of the front axle includes the front unsprung speed and the front unsprung acceleration; The obtaining of unsprung information of the front axle of the vehicle includes: Acquire the front spring under-acceleration collected by an acceleration sensor installed under the front spring, and obtain the front spring under-speed by integrating the front spring under-acceleration; or Acquire height information collected by a height sensor installed on the front suspension, determine the speed and acceleration of the front suspension based on the height information, acquire the speed and acceleration of the front tower top collected by a tower top acceleration sensor, and determine the front unsprung speed and the front unsprung acceleration based on the speed and acceleration of the front suspension and the speed and acceleration of the front tower top.

8. A suspension state determination device, characterized in that: The device comprises: An acquisition module, used for acquiring unsprung information of a front axle of a vehicle; an estimation module, configured to determine delay information of the front axle and the rear axle passing through the same position according to the wheelbase between the front axle and the rear axle, and determine unsprung information of the rear axle according to the delay information and unsprung information of the front axle; A first building block is used to establish a sprung motion equation and an unsprung motion equation according to a seven-degree-of-freedom model of the vehicle; A second building block is used to establish a state equation according to the unsprung motion equation, and to establish an observation equation according to the sprung motion equation, the unsprung information of the front axle, and the unsprung information of the rear axle; The correction module is used to perform Kalman filtering on the unsprung information of the rear axle according to the state equation and the observation equation, and output optimized unsprung information of the rear axle.

9. An electronic device, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a program or an instruction that can be run on the processor, and when the program or the instruction is executed by the processor, the steps of the suspension state determination method according to any one of claims 1 to 7 are implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a program or an instruction, and when the program or the instruction is executed by the processor, the steps of the suspension state determination method according to any one of claims 1 to 7 are implemented.

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