Steering transmission system, method, steering system, controller, medium and vehicle

Abstract

The present invention discloses a steering transmission system, method, steering system, controller, medium and vehicle. The steering transmission system includes a front axle rotating mechanism, a rear axle rotating mechanism and a vibration damping adjustment mechanism; one end of the front axle rotating mechanism and the rear axle rotating mechanism is suitable for connecting different steering output mechanisms; the other end of the front axle rotating mechanism and the rear axle rotating mechanism is suitable for connecting a steering input mechanism; the vibration damping adjustment mechanism is arranged on the rear axle rotating mechanism. In this scheme, when the vehicle has a multi-limit cycle shimmy phenomenon, the vibration damping adjustment mechanism can be controlled to adjust the rear axle rotating mechanism until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a steering transmission system, method, steering system, controller, medium and vehicle. Background Art

[0002] The existing steering transmission system includes two types: a single steering system and a steering transmission system. Compared with the single steering system, the steering transmission system has a more complex structure, which makes it prone to multi-limit cycle oscillation and presents multi-frequency and multi-amplitude characteristics. Multi-limit cycle oscillation will cause the stability of the steering transmission system to change suddenly with parameter changes, making it difficult to control the driving direction, affecting the driving safety and handling stability of the vehicle. Therefore, it is urgent to provide improvements to the steering transmission system to avoid the multi-limit cycle oscillation phenomenon and affect the driving direction of the vehicle. Summary of the invention

[0003] The embodiments of the present invention provide a steering transmission system, method, steering system, controller, medium and vehicle to solve the problem that the existing steering transmission system has a multi-limit cycle shimmy phenomenon and affects the driving direction of the vehicle.

[0004] A steering transmission system comprises a front axle rotation mechanism, a rear axle rotation mechanism and a vibration reduction adjustment mechanism;

[0005] One end of the front axle rotating mechanism and the rear axle rotating mechanism is suitable for connecting to a steering input mechanism; the other end of the front axle rotating mechanism and the rear axle rotating mechanism is suitable for connecting to different steering output mechanisms;

[0006] The vibration damping adjustment mechanism is arranged on the rear axle rotation mechanism.

[0007] Preferably, the vibration damping adjustment mechanism includes a stiffness adjustment unit arranged on the rear axle rotation mechanism.

[0008] Preferably, the vibration reduction adjustment mechanism further includes a damping adjustment unit arranged on the front axle rotation mechanism.

[0009] Preferably, the front axle rotation mechanism comprises a front axle steering tie rod;

[0010] The damping adjustment unit is arranged on the front axle steering tie rod.

[0011] Preferably, the damping adjustment unit includes a magnetorheological shock absorber, an oil shock absorber or a magnetic resistance shock absorber.

[0012] Preferably, the rear axle rotation mechanism comprises a rear axle steering straight tie rod;

[0013] The stiffness adjustment unit is arranged on the rear axle steering tie rod.

[0014] Preferably, the stiffness adjustment unit comprises an air spring, a hydraulic cylinder or an electromagnetic solenoid.

[0015] Preferably, the steering transmission system further comprises a transmission mechanism, wherein the transmission mechanism is connected to the steering input mechanism and is connected to the front axle rotation mechanism and the rear axle rotation mechanism.

[0016] A steering transmission control method, comprising:

[0017] Acquiring first vehicle data;

[0018] When the first vehicle data satisfies a multi-limit cycle shimmy condition, controlling a vibration reduction adjustment mechanism of the steering transmission system to perform a vibration reduction operation;

[0019] Wherein, the steering transmission system is the above-mentioned steering transmission system.

[0020] Preferably, after acquiring the first vehicle data, the steering transmission control method further includes:

[0021] Determining a shimmy evaluation index corresponding to the shimmy dynamics model based on a shimmy dynamics model corresponding to the steering transmission system, wherein the shimmy dynamics model is determined based on the first vehicle data;

[0022] If the shimmy evaluation index is not within a preset threshold range, it is determined that the first vehicle data satisfies a multi-limit cycle shimmy condition.

[0023] Preferably, the shimmy dynamics model is determined based on polynomial fitting equations corresponding to a plurality of system degrees of freedom;

[0024] The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the first vehicle data, and the system degrees of freedom are free variables in the shimmy dynamics model.

[0025] Preferably, the first vehicle data includes chassis data and vehicle data corresponding to the steering transmission system;

[0026] The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom and the vehicle data;

[0027] The dynamic equations corresponding to the plurality of system degrees of freedom are determined based on chassis data corresponding to the steering transmission system.

[0028] Preferably, the polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom, the tire lateral force and the friction torque;

[0029] The tire lateral force and the friction torque are determined based on the whole vehicle data.

[0030] Preferably, the vehicle data includes wheel slip angle, wheel camber angle and tire vertical force;

[0031] The tire lateral force is determined based on the wheel slip angle; and the friction torque is determined based on the wheel camber angle and the tire vertical force.

[0032] Preferably, the shimmy dynamics model corresponding to the steering transmission system is determined based on a variable vector, a first-order derivative of the variable vector, a Jacobian matrix of the steering transmission system at an equilibrium point, and nonlinear multi-order terms corresponding to the variable vector;

[0033] The variable vector is determined based on a plurality of system degrees of freedom and a first-order derivative of a plurality of system degrees of freedom;

[0034] The nonlinear multi-terms are determined based on polynomial fitting equations corresponding to the plurality of system degrees of freedom.

[0035] Preferably, the shimmy evaluation index is a dynamic stability index determined by performing a dynamic balance analysis on the shimmy dynamics model.

[0036] Preferably, the dynamic stability index is the real part of the derivative of the characteristic root corresponding to the pure imaginary root of the Jacobian matrix at the critical vehicle speed with respect to the vehicle speed.

[0037] Preferably, the vibration reduction adjustment mechanism for controlling the steering transmission system to perform vibration reduction operation includes:

[0038] Controlling the vibration reduction adjustment mechanism of the steering transmission system to perform vibration reduction operation based on target parameters;

[0039] The target parameter is determined based on second vehicle data.

[0040] Preferably, the vibration damping adjustment mechanism comprises a stiffness adjustment unit provided on the rear axle rotation mechanism;

[0041] The target parameters include a target stiffness.

[0042] Preferably, the second vehicle data includes vehicle speed;

[0043] The target stiffness is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a first vehicle speed interval to which the vehicle speed belongs.

[0044] Preferably, the vibration reduction adjustment mechanism further comprises a damping adjustment unit arranged on the front axle rotation mechanism;

[0045] The target parameters include target damping.

[0046] Preferably, the second vehicle data includes vehicle speed;

[0047] The target damping is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a second vehicle speed interval to which the vehicle speed belongs.

[0048] A steering system, comprising a steering input mechanism, a steering output mechanism and the above-mentioned steering transmission system;

[0049] The steering input mechanism is connected to the front axle rotation mechanism and the rear axle rotation mechanism;

[0050] The steering output mechanism is connected to the front axle rotation mechanism and the rear axle rotation mechanism.

[0051] Preferably, the steering system further comprises a transmission mechanism, wherein the transmission mechanism is connected to the steering input mechanism and is connected to the front axle rotation mechanism and the rear axle rotation mechanism.

[0052] Preferably, the steering input mechanism comprises a steering wheel, a steering motor and a steering control module;

[0053] The steering wheel is connected to the transmission mechanism;

[0054] The steering motor is connected to the steering wheel and is used to control the rotation of the steering wheel.

[0055] Preferably, the steering output mechanism includes a left front wheel, a right front wheel, a left rear wheel and a right rear wheel;

[0056] The front axle rotating mechanism is connected to the left front wheel and the right front wheel;

[0057] The rear axle rotation mechanism is connected to the left rear wheel and the right rear wheel.

[0058] A vehicle-mounted controller comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned steering transmission control method when executing the computer program.

[0059] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steering transmission control method is implemented.

[0060] A vehicle comprises the above-mentioned steering transmission system, or the above-mentioned steering system, or the above-mentioned on-board controller, or the above-mentioned computer-readable storage medium.

[0061] The above-mentioned steering transmission system, method, steering system, controller, medium and vehicle, when determining that the vehicle has a multi-limit cycle shimmy phenomenon based on the first vehicle data, can control the damping adjustment unit to adjust the damping of the front axle rotation mechanism, and / or adjust the stiffness of the rear axle rotation mechanism through the stiffness adjustment unit until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0063] Figure 1 is a schematic diagram of a steering transmission system in one embodiment of the present invention;

[0064] Figure 2 is a flow chart of a steering transmission control method in one embodiment of the present invention;

[0065] Figure 3 is another flow chart of the steering transmission control method in one embodiment of the present invention.

[0066] In the figure: 10, steering input mechanism; 11, steering wheel; 12, steering gear; 20, front axle rotation mechanism; 21, front axle axle; 22, front axle steering tie rod; 23, front axle kingpin; 24, front axle connecting rod; 25, front axle steering knuckle arm; 26, front axle steering straight tie rod; 30, rear axle rotation mechanism; 31, rear axle axle; 32, rear axle steering tie rod; 33, rear axle kingpin; 34, rear axle connecting rod; 35, rear axle steering knuckle arm; 36, rear axle steering straight tie rod; 40, vibration reduction adjustment mechanism; 41, stiffness adjustment unit; 42, damping adjustment unit; 50, transmission mechanism; 51, first vertical arm; 52, middle vertical arm; 53, second vertical arm; 54, first connecting rod; 55, second connecting rod; 61, right front wheel; 62, left front wheel; 63, right rear wheel; 64, left rear wheel. DETAILED DESCRIPTION

[0067] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] The embodiment of the present invention provides a steering transmission system, such as Figure 1 As shown, the steering transmission system includes a front axle rotation mechanism 20, a rear axle rotation mechanism 30 and a vibration reduction adjustment mechanism 40;

[0069] One end of the front axle rotating mechanism 20 and the rear axle rotating mechanism 30 is suitable for connecting to the steering input mechanism 10, and the other end of the front axle rotating mechanism 20 and the rear axle rotating mechanism 30 is suitable for connecting to different steering output mechanisms;

[0070] The vibration damping adjustment mechanism 40 is disposed on the rear axle rotation mechanism 30 .

[0071] As an example, the steering transmission system includes a front axle rotation mechanism 20, a rear axle rotation mechanism 30, and a vibration reduction adjustment mechanism 40. The front axle rotation mechanism 20 is suitable for connecting the steering input mechanism 10 and the two front axle wheels (i.e., one steering output mechanism) to control the rotation of the two front axle wheels. The rear axle rotation mechanism 30 is suitable for connecting the steering input mechanism 10 and the two rear axle wheels (i.e., another steering output mechanism) to control the rotation of the two rear axle wheels. That is to say, the steering input mechanism 10 is connected to one end of the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, and the other ends of the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 are connected to different steering output mechanisms, so that when the driver operates the steering input mechanism 10, the front axle wheels and the rear axle wheels can be controlled to rotate in both directions.

[0072] In this example, the vibration reduction adjustment mechanism 40 is arranged on the rear axle rotation mechanism 30, and the variable parameters of some components in the rear axle rotation mechanism 30 can be adjusted so that the adjusted rear axle rotation mechanism 30 has a vibration reduction effect. In this example, the vibration reduction adjustment mechanism 40 is suitable for being connected to a vehicle-mounted controller. During the driving of the vehicle, the vehicle-mounted controller can obtain the first vehicle data, and evaluate whether the vehicle has a multi-limit cycle shimmy phenomenon based on the first vehicle data; if there is a multi-limit cycle shimmy phenomenon, the vibration reduction adjustment mechanism 40 arranged on the rear axle rotation mechanism 30 is controlled to adjust its variable parameters to target parameters until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon from affecting the driving of the vehicle, thereby ensuring the driving safety and handling stability of the vehicle. The first vehicle data here is the data collected in real time for evaluating whether there is a multi-limit cycle shimmy phenomenon. The target parameter here is the parameter that needs to control the vibration reduction adjustment mechanism 40 to work to slow down the multi-limit cycle shimmy phenomenon.

[0073] In one embodiment, the vibration damping adjustment mechanism 40 includes a stiffness adjustment unit 41 disposed on the rear axle rotation mechanism 30 .

[0074] As an example, the vibration damping adjustment mechanism 40 includes a stiffness adjustment unit 41 disposed on the rear axle rotation mechanism 30, which is used to adjust the stiffness of some components in the rear axle rotation mechanism 30. In this example, the stiffness adjustment unit 41 is suitable for being connected to a vehicle-mounted controller. When the vehicle-mounted controller determines that there is a multi-limit cycle shimmy phenomenon based on the first vehicle data evaluation of the vehicle during the driving of the vehicle, the stiffness adjustment unit 41 can be controlled to adjust the stiffness of the rear axle rotation mechanism 30, and specifically adjust the variable stiffness of the rear axle rotation mechanism 30 to reach a target stiffness that can slow down the multi-limit cycle shimmy phenomenon until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon from affecting the driving of the vehicle, thereby ensuring the driving safety and handling stability of the vehicle. The target stiffness here is the stiffness that needs to control the stiffness adjustment unit 41 to work.

[0075] In one embodiment, the vibration reduction adjustment mechanism 40 further includes a damping adjustment unit 42 disposed on the front axle rotation mechanism 20 .

[0076] As an example, the vibration reduction adjustment mechanism 40 further includes a damping adjustment unit 42 disposed on the front axle rotation mechanism 20, for adjusting the damping of some components in the front axle rotation mechanism 20. In this example, the damping adjustment unit 42 is adapted to be connected to a vehicle-mounted controller. When the vehicle is traveling and the vehicle-mounted controller determines that there is a multi-limit cycle shimmy phenomenon based on the first vehicle data evaluation, the vehicle-mounted controller can not only control the stiffness adjustment unit 41 to adjust the stiffness of the rear axle rotation mechanism 30, but also control the damping adjustment unit 42 to adjust the damping of the front axle rotation mechanism 20, specifically adjusting the variable damping of the front axle rotation mechanism 20 to achieve a target damping that can slow down the multi-limit cycle shimmy phenomenon until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon from affecting the vehicle driving, thereby ensuring the driving safety and handling stability of the vehicle.

[0077] In one embodiment, if Figure 1 As shown, the front axle rotation mechanism 20 includes a front axle steering tie rod 22 ; the damping adjustment unit 42 is arranged on the front axle steering tie rod 22 .

[0078] As an example, the front axle rotation mechanism 20 includes a front axle axle 21, a front axle steering tie rod 22, a front axle kingpin 23, a front axle connecting rod 24, a front axle steering knuckle arm 25 and a front axle steering straight tie rod 26. The two front axle kingpins 23 are suitable for being installed on the right front wheel 61 and the left front wheel 62, so that the right front wheel 61 and the left front wheel 62 can rotate around their corresponding front axle kingpins 23 respectively. The two ends of the front axle axle 21 are respectively connected to the two front axle kingpins 23, and the two ends of the front axle steering tie rod 22 are respectively connected to the two front axle kingpins 23 through the front axle connecting rod 24, so that the two front axle wheels are linked. The first end of the front axle steering knuckle arm 25 is connected to the front axle kingpin 23, and the second end of the front axle steering knuckle arm 25 is connected to the front axle steering tie rod 26. The front axle steering tie rod 26 is connected to the steering input mechanism 10 through the transmission mechanism 50 to transmit the power of the steering input mechanism 10 to the front axle kingpin 23, thereby controlling the rotation of the two front axle wheels. In this example, the damping adjustment unit 42 is provided on the front axle steering tie rod 22. When the vehicle has a multi-limit cycle shimmy phenomenon, the damping of the front axle steering tie rod 22 can be dynamically adjusted by the damping adjustment unit 42. Specifically, the variable damping of the front axle steering tie rod 22 is adjusted to achieve the target damping that can slow down the multi-limit cycle shimmy phenomenon, so that the multi-limit cycle shimmy phenomenon can be slowed down to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0079] In one embodiment, the damping adjustment unit 42 includes a magnetorheological shock absorber, an oil shock absorber or a magnetic resistance shock absorber.

[0080] As an example, the damping adjustment unit 42 can be a magnetorheological shock absorber, an oil shock absorber or a reluctance shock absorber, which can be arranged on the front axle steering tie rod 22 to adjust the variable damping of the front axle steering tie rod 22 to slow down the multi-limit cycle shimmy phenomenon, so as to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0081] In one embodiment, if Figure 1 As shown, the rear axle rotation mechanism 30 includes a rear axle steering straight tie rod 36 ; the stiffness adjustment unit 41 is disposed on the rear axle steering straight tie rod 36 .

[0082] As an example, the rear axle rotation mechanism 30 includes a rear axle shaft 31, a rear axle steering tie rod 32, a rear axle kingpin 33, a rear axle connecting rod 34, a rear axle steering knuckle arm 35 and a rear axle steering straight tie rod 36. The two rear axle kingpins 33 are suitable for being installed on the right rear wheel 63 and the left rear wheel 64, so that the right rear wheel 63 and the left rear wheel 64 can rotate around their corresponding rear axle kingpins 33 respectively. The two ends of the rear axle shaft 31 are respectively connected to the two rear axle kingpins 33, and the two ends of the rear axle steering tie rod 32 are respectively connected to the two rear axle kingpins 33 through the rear axle connecting rod 34, so that the two rear axle wheels are linked. The first end of the rear axle steering knuckle arm 35 is connected to the rear axle kingpin 33, and the second end of the rear axle steering knuckle arm 35 is connected to the rear axle steering straight tie rod 36. The rear axle steering straight tie rod 36 is connected to the steering input mechanism 10 through the transmission mechanism 50 to transmit the power of the steering input mechanism 10 to the rear axle kingpin 33, thereby controlling the rotation of the two rear axle wheels. In this example, the rear axle steering straight tie rod 36 is provided with the stiffness adjustment unit 41. When the vehicle has a multi-limit cycle shimmy phenomenon, the stiffness of the rear axle steering straight tie rod 36 can be dynamically adjusted through the stiffness adjustment unit 41, so that the multi-limit cycle shimmy phenomenon can be slowed down to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0083] In one embodiment, the stiffness adjustment unit 41 includes an air spring, a hydraulic cylinder or an electromagnetic solenoid.

[0084] As an example, the stiffness adjustment unit 41 can be an air spring connected to the rear axle steering tie rod 36. The air spring can dynamically adjust its spring compression to adjust the stiffness of the rear axle steering tie rod 36 to mitigate the multi-limit cycle shimmy phenomenon, so as to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0085] As an example, the stiffness adjustment unit 41 can be a hydraulic cylinder connected to the rear axle steering tie rod 36. The hydraulic cylinder can dynamically adjust its hydraulic pressure to adjust the stiffness of the rear axle steering tie rod 36 to mitigate the multi-limit cycle oscillation phenomenon, so as to avoid the multi-limit cycle oscillation phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0086] As an example, the stiffness adjustment unit 41 may be an electromagnetic solenoid connected to the rear axle steering tie rod 36, which may adjust the stiffness of the rear axle steering tie rod 36 to mitigate the multi-limit cycle oscillation phenomenon, thereby preventing the multi-limit cycle oscillation phenomenon from affecting vehicle driving, thereby ensuring vehicle driving safety and handling stability.

[0087] It is understandable that the stiffness adjustment unit 41 may also be other structures capable of achieving stiffness adjustment except for the air spring, the hydraulic cylinder or the electromagnetic solenoid.

[0088] In one embodiment, the steering transmission system further includes a transmission mechanism 50 , which is suitable for connecting to the steering input mechanism 10 and connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 .

[0089] As an example, the steering transmission system also includes the transmission mechanism 50, which is suitable for being installed on the vehicle body assembly, and is connected to the steering input mechanism 10 for receiving power from the steering input mechanism 10; and the transmission mechanism 50 is also connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, and can transmit power to different steering output mechanisms through the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, so that when the driver operates the steering input mechanism 10, the front axle wheels and the rear axle wheels can be controlled to rotate in both directions.

[0090] As an example, Figure 1 As shown, the transmission mechanism 50 includes a first hanging arm 51, an intermediate hanging arm 52, a second hanging arm 53, a first connecting rod 54 and a second connecting rod 55. The two ends of the first hanging arm 51 are respectively connected to the steering input mechanism 10 and the front axle rotating mechanism 20, that is, the first end of the first hanging arm 51 is connected to the steering input mechanism 10, and the second end of the first hanging arm 51 is connected to the front axle rotating mechanism 20, specifically connected to the front axle steering straight tie rod 26 in the front axle rotating mechanism 20, for transmitting the power of the steering input mechanism 10 to the front axle rotating mechanism 20, so as to drive the two front axle wheels to rotate. The first end of the first drop arm 51 is connected to the steering input mechanism 10; the first end of the first connecting rod 54 is connected to the middle of the first drop arm 51, and the second end of the first connecting rod 54 is connected to the second end of the intermediate drop arm 52; the second end of the second connecting rod 55 is connected to the middle of the intermediate drop arm 52, and the second end of the second connecting rod 55 is connected to the middle of the second drop arm 53; the second end of the second drop arm 53 is connected to the rear axle rotation mechanism 30, so that the power transmitted by the steering input mechanism 10 passes through the first drop arm 51, the first connecting rod 54, the intermediate drop arm 52, the second connecting rod 55 and the second drop arm 53 in sequence, and is connected to the rear axle steering straight pull rod 36 of the rear axle rotation mechanism 30 to drive the two rear axle wheels to rotate.

[0091] In one embodiment, if Figure 2As shown, a steering transmission control method is provided, which can be applied to a vehicle-mounted controller, where the vehicle-mounted controller is a controller installed on a vehicle; the vehicle-mounted controller is connected to the steering transmission system, specifically to the vibration reduction adjustment mechanism 40 of the steering transmission system, and the variable parameters of the vibration reduction adjustment mechanism 40 can be adjusted according to the control of the vehicle-mounted controller. Figure 2 As shown, the steering transmission control method includes:

[0092] S201: Acquire first vehicle data;

[0093] S202: When the first vehicle data satisfies a multi-limit cycle shimmy condition, controlling a vibration reduction adjustment mechanism of a steering transmission system to perform a vibration reduction operation;

[0094] Wherein, the steering transmission system is the steering transmission system in the above embodiment.

[0095] The first vehicle data is vehicle data collected in real time. The multiple limit cycle shimmy condition is a pre-set condition for evaluating whether the multiple limit cycle shimmy phenomenon occurs.

[0096] As an example, during the driving of the vehicle, the on-board controller can obtain first vehicle data through a bus or other communication modules, and then compare the first vehicle data with the multi-limit cycle shimmy condition; if the first vehicle data satisfies the multi-limit cycle shimmy condition, it is determined that the vehicle has a multi-limit cycle shimmy phenomenon, and the vibration reduction adjustment mechanism 40 of the steering transmission system can be controlled to perform a vibration reduction operation. For example, the vibration reduction adjustment mechanism 40 arranged on the rear axle rotation mechanism 30 can be controlled to adjust its variable parameters until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon affecting the driving of the vehicle, thereby ensuring the driving safety and handling stability of the vehicle.

[0097] In one embodiment, if Figure 3 As shown, after acquiring the first vehicle data, the steering transmission control method further includes:

[0098] S301: determining a shimmy evaluation index corresponding to the shimmy dynamics model based on a shimmy dynamics model corresponding to the steering transmission system, wherein the shimmy dynamics model is determined based on the first vehicle data;

[0099] S302: If the shimmy evaluation index is not within a preset threshold range, determining that the first vehicle data satisfies a multi-limit cycle shimmy condition.

[0100] As an example, in step S301, after acquiring the first vehicle data, the onboard controller may determine the shimmy dynamics model corresponding to the steering transmission system based on the first vehicle data, and then analyze and process the shimmy dynamics model corresponding to the steering transmission system to determine the shimmy evaluation index corresponding to the shimmy dynamics model. For example, the onboard controller may perform a derivative or other analysis and processing on the shimmy dynamics model to determine, based on the processing result, a shimmy evaluation index for reflecting whether a multi-limit cycle shimmy phenomenon occurs. The shimmy evaluation index herein is an index value for reflecting whether a multi-limit cycle shimmy phenomenon occurs, which is determined by analyzing and processing the shimmy dynamics model.

[0101] In this example, after acquiring the first vehicle data, the on-board controller may process the first vehicle data based on a pre-set rule for building a dynamic model to determine the shimmy dynamic model corresponding to the steering transmission system. In this example, the pre-set dynamic model building rule may be a rule determined based on the Lagrange equation, or a rule determined using other algorithms. For example, in the dynamic model building rule determined based on the Lagrange equation, a correlation between the first vehicle data corresponding to multiple system degrees of freedom and the kinetic energy T, potential energy U, entropy E, and generalized force Gk may be established, so that the first vehicle data may be subsequently substituted into the dynamic model building rule to dynamically determine the corresponding shimmy dynamic model of the steering transmission system.

[0102] Among them, the preset threshold range is a preset threshold range corresponding to the shimmy evaluation index for determining whether the vehicle is stable. If the shimmy evaluation index is within the preset threshold range, it means that the vehicle is driving relatively smoothly; if the shimmy evaluation index is not within the preset threshold range, it means that there is a high probability that multiple limit cycle shimmy will occur during the vehicle driving process.

[0103] As an example, in step S302, after determining the shimmy evaluation index corresponding to the shimmy dynamics model, the on-board controller may compare the shimmy evaluation index with a preset threshold range. If the shimmy evaluation index is not within the preset threshold range, it means that the vehicle is very likely to have a multi-limit cycle shimmy phenomenon. Therefore, it is determined that the multi-limit cycle shimmy condition is met, and it is necessary to control the vibration reduction adjustment mechanism 40 of the steering transmission system to perform a vibration reduction operation to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0104] In this example, based on the first vehicle data, a shimmy evaluation index corresponding to the shimmy dynamics model of the steering transmission system is determined, and according to the shimmy evaluation index and shimmy index condition determined in real time, it is evaluated from a dynamic perspective whether a multi-limit cycle shimmy phenomenon occurs, so as to determine whether a vibration reduction operation is required based on the evaluation result, thereby ensuring the driving safety and handling stability of the vehicle.

[0105] In one embodiment, the shimmy dynamics model is determined based on polynomial fitting equations corresponding to a plurality of system degrees of freedom;

[0106] The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the first vehicle data, and the system degrees of freedom are free variables in the shimmy dynamics model.

[0107] As an example, after acquiring the first vehicle data, the on-board controller can determine the specific data corresponding to the model variables in the shimmy dynamics model from the first vehicle data, that is, determine the specific data corresponding to multiple system degrees of freedom; then, based on the specific data corresponding to the multiple system degrees of freedom, construct a polynomial fitting equation corresponding to the multiple system degrees of freedom; then, perform a dynamic balance analysis on the polynomial fitting equation corresponding to the multiple system degrees of freedom, for example, the analysis and processing can be performed using but not limited to the Lyapunov function to determine the shimmy dynamics model of the steering transmission system.

[0108] For example, the first vehicle data includes a plurality of system degrees of freedom associated with a shimmy dynamics model, for example, a plurality of system degrees of freedom q k include α 1 、α 2 , α 3 , α 4 , β 1 , β 2 , c 1 , c 2 and c 3 ,in k = 9, α 1 is the turning angle of the right front wheel 61 around the front axle kingpin 23; α 2 The turning angle of the left front wheel 62 around the front axle kingpin 23; α 3 is the turning angle of the right rear wheel 63 around the rear axle kingpin 33; α 4 are respectively the turning angle of the left rear wheel 64 around the rear axle kingpin 33; β 1 is the roll angle of the front axle rotation mechanism 20; β 2 the roll angle of the rear axle pivot mechanism 30; c 1 , c2 and c 3 are the swing angles of the first drop arm 51, the middle drop arm 52 and the second drop arm 53 around their pivot points, respectively. The steering transmission system corresponds to 9 system degrees of freedom. q k It can be expressed as: Based on the specific data corresponding to the 9 system degrees of freedom, a polynomial fitting equation corresponding to the multiple system degrees of freedom can be constructed; then, a dynamic balance analysis is performed on the polynomial fitting equation corresponding to the 9 system degrees of freedom to determine the corresponding swing dynamics model.

[0109] In one embodiment, the first vehicle data includes chassis data and vehicle data corresponding to the steering transmission system;

[0110] The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom and the vehicle data;

[0111] The dynamic equations corresponding to the plurality of system degrees of freedom are determined based on chassis data corresponding to the steering transmission system.

[0112] The chassis data refers to the data collected by the chassis domain controller, specifically the data collected by the sensor (including but not limited to the angle sensor) connected to the chassis domain controller, which is set on the steering transmission system and is used to collect steering-related data of the steering transmission system. The vehicle data refers to the data collected by the vehicle controller, specifically the data related to the driving state of the vehicle, which is the data corresponding to the variable values ​​in the dynamic equations corresponding to the multiple system degrees of freedom.

[0113] As an example, the vehicle controller can obtain chassis data corresponding to the steering transmission system through a bus or other communication modules, and the chassis data corresponding to the steering transmission system includes multiple system degrees of freedom related to the shimmy dynamics model, for example, multiple system degrees of freedom q k include α 1 、α 2 , α 3 , α 4 , β 1 , β 2 , c 1 , c 2 and c 3 ,in k= 9, α 1 is the turning angle of the right front wheel 61 around the front axle kingpin 23; α 2 The turning angle of the left front wheel 62 around the front axle kingpin 23; α 3 is the turning angle of the right rear wheel 63 around the rear axle kingpin 33; α 4 are respectively the turning angle of the left rear wheel 64 around the rear axle kingpin 33; β 1 is the roll angle of the front axle rotation mechanism 20; β 2 the roll angle of the rear axle pivot mechanism 30; c 1 , c 2 and c 3 are the swing angles of the first vertical arm 51, the middle vertical arm 52 and the second vertical arm 53 around their pivot points, and the multiple system degrees of freedom are q k It can be expressed as:

[0114] .

[0115] In this example, after obtaining the chassis data corresponding to the 9 system degrees of freedom, the on-board controller can establish multiple dynamic equations based on the Lagrange equations of kinetic energy T, potential energy U, entropy E, and generalized force Gk. Specifically, the dynamic equations corresponding to the 9 system degrees of freedom are established as follows: (1)

[0116] (2)

[0117] (3)

[0118] (4)

[0119] Formula (1) is the dynamic equation for the right front wheel 61 to rotate around the front axle kingpin 23, Formula (2) is the dynamic equation for the left front wheel 62 to rotate around the front axle kingpin 23, Formula (3) is the dynamic equation for the right rear wheel 63 to rotate around the rear axle kingpin 33, and Formula (4) is the dynamic equation for the left rear wheel 64 to rotate around the rear axle kingpin 33.

[0120] In formula (1) to formula (4), I w1 is the moment of inertia of the right front wheel 61 rotating around its corresponding front axle kingpin 23, I w2 is the moment of inertia of the left front wheel 62 around the axis of its corresponding front axle kingpin 23, d w1is the steering damping of the right front wheel 61, d w2 is the steering damping of the left front wheel 62, c h1 is the stiffness of the front axle steering tie rod 22, c h2 is the stiffness of the rear axle steering tie rod 32, d h1 is the damping of the front axle steering tie rod 22, d h2 It is the damping of the rear axle steering tie rod 32.

[0121] Since the damping adjustment unit 42 is provided on the front axle steering tie rod 22, the damping of the front axle steering tie rod 22 d h1 It is expressed as the following formula:

[0122] ;

[0123] in d z0 is the constant damping of the front axle steering tie rod 22, d h1 ( v ) is the variable damping of the front axle steering tie rod 22, which is specifically adjusted by the damping adjustment unit 42. The damping adjustment unit 42 may be, but is not limited to, a magnetorheological shock absorber.

[0124] J w1 is the axial moment of inertia of the front axle wheels (right front wheel 61 and left front wheel 62), J w2 is the axial moment of inertia of the rear axle wheels (right rear wheel 63 and left rear wheel 64), v is the vehicle speed, R w is the rolling radius of the wheel, c wy is the lateral stiffness of the wheel, H 1 is the suspension roll center height of the front axle pivot mechanism 20, H 2 is the suspension roll center height of the rear axle pivot mechanism 30, A caster The caster angle includes the caster angle of the front axle kingpin 23 or the caster angle of the rear axle kingpin 33. c wz is the radial stiffness of the wheel, l 1 is the distance from the intersection of the extension line of the front axle kingpin 23 and the road surface to the wheel symmetry plane, l 2is the distance from the intersection of the extended line of the rear axle kingpin 33 and the road surface to the wheel symmetry plane, B 1 is the front axle track, B 2 is the rear axle track, f is the friction coefficient between the wheel and the ground, e is the tire trail, F wy1 is the tire lateral force of the right front wheel 61, F wy2 is the tire lateral force of the left front wheel 62, F wy3 is the tire lateral force of the right rear wheel 63, F wy4 is the tire lateral force of the left rear wheel 64, M wy1 is the friction torque between the right front wheel 61 and its corresponding front axle kingpin 23, M wy2 is the friction torque between the left front wheel 62 and its corresponding front axle kingpin 23, M wy3 is the friction torque between the right rear wheel 63 and its corresponding rear axle kingpin 33, M wy4 is the friction torque between the left rear wheel 64 and its corresponding rear axle kingpin 33; d z1 The damping of the rear axle steering tie rod 36 is d z2 The damping of the rear axle steering tie rod 36 is c z1 is the stiffness of the front axle steering tie rod 26, c z2 is the stiffness of the rear axle steering tie rod 36

[0125] Since the stiffness adjustment unit 41 is provided on the rear axle steering tie rod 36, the stiffness of the rear axle steering tie rod 36 is c z2 It is expressed as the following formula:

[0126] ;

[0127] in c z0 is the constant stiffness of the rear axle steering tie rod 36, c z2 ( v ) is the variable stiffness of the rear axle steering tie rod 36, which can be adjusted by the stiffness adjustment unit 41. The stiffness adjustment unit 41 can be but is not limited to an air spring, a hydraulic cylinder or an electromagnetic solenoid.

[0128] (5)

[0129] (6)

[0130] Formula (5) is the dynamic equation corresponding to the roll angle of the front axle rotation mechanism 20; Formula (6) is the dynamic equation corresponding to the roll angle of the rear axle rotation mechanism 30.

[0131] I q1 is the moment of inertia of the front axle rotation mechanism 20 around its roll axis, I q2 is the moment of inertia of the rear axle pivot mechanism 30 about its roll axis, d q1 is the suspension roll damping of the front axle pivot mechanism 20, d q2 is the suspension roll damping of the rear axle pivot mechanism 30, c q1 is the roll angle stiffness of the front axle pivot mechanism 20, c q2 is the roll angle stiffness of the rear axle pivot mechanism 30 .

[0132] (7)

[0133] (8)

[0134] (9)

[0135] Formula (7) is the dynamic equation of the first vertical arm 51 rotating around its pivot point, Formula (8) is the dynamic equation of the middle vertical arm 52 rotating around its pivot point, and Formula (9) is the dynamic equation of the second vertical arm 53 rotating around its pivot point.

[0136] I c1 , I c2 and I c3 are the moments of inertia of the first hanging arm 51, the middle hanging arm 52 and the second hanging arm 53 around their upper pivot points, d z is the reverse damping from the first drop arm 51 to the steering input mechanism 10, c z is the inverse stiffness from the first drop arm 51 to the steering input mechanism 10, d l1 is the damping of the first connecting rod 54, d l2 is the damping of the second connecting rod 55, g 1 , g 2and g 3 are the lengths of the first drop arm 51, the middle drop arm 52, the second drop arm 53 and the connection points of the connecting rods, r 1 , r 2 and r 3 are the lengths of the first hanging arm 51, the middle hanging arm 52 and the second hanging arm 53, respectively. h 1 is the distance from the connection point between the front axle steering knuckle arm 25 and the front axle steering straight tie rod 26 to the front axle kingpin 23, h 2 is the distance from the connection point between the rear axle steering knuckle arm 35 and the rear axle steering straight tie rod 36 to the rear axle kingpin 33, c l1 is the stiffness of the first connecting rod 54, c l2 is the stiffness of the second connecting rod 55.

[0137] As an example, after the vehicle controller determines the dynamic equations corresponding to the 9 system degrees of freedom, each of the dynamic equations contains multiple variables. The vehicle controller can directly determine the variable values ​​corresponding to these variables based on the vehicle data, or perform calculations on the vehicle data to indirectly determine the variable values ​​corresponding to these variables; then, the variable values ​​corresponding to the multiple variables are substituted into the dynamic equations corresponding to the 9 system degrees of freedom determined to determine the polynomial fitting equations corresponding to the 9 system degrees of freedom. In other words, the polynomial fitting equation corresponding to each system degree of freedom is the result of substituting the variable values ​​into the dynamic equation, and can be used as the equation determined for solving the dynamic equation based on the vehicle data.

[0138] In this example, the corresponding dynamic equations are constructed based on the chassis data corresponding to the multiple system degrees of freedom, and the dynamic equations are solved using the whole vehicle data. The polynomial fitting equations related to the multiple system degrees of freedom can be quickly obtained, and then the shimmy dynamic model corresponding to the steering transmission system can be determined, so as to dynamically determine the shimmy dynamic model, which helps to ensure the accuracy of the vibration reduction operation.

[0139] In one embodiment, the polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom, the tire lateral force and the friction torque;

[0140] The tire lateral force and the friction torque are determined based on the whole vehicle data.

[0141] As an example, the dynamic equations corresponding to the multiple system degrees of freedom determined by the on-board controller include tire lateral force and friction torque, two key variables that affect the shimmy phenomenon of the steering transmission system. It is necessary to determine the variable values ​​corresponding to these two key variables based on the whole vehicle data collected in real time during the vehicle driving process. It can be determined by direct detection by sensors that directly measure these two key variables, or by collecting other parameters and performing mathematical operations on these parameters. Then, the tire lateral force and friction torque determined based on the whole vehicle data are substituted into the dynamic equations corresponding to the multiple system degrees of freedom for calculation and processing, and the polynomial fitting equations corresponding to the multiple system degrees of freedom are determined, so as to solve the dynamic equations based on the tire lateral force and friction torque determined by the whole vehicle data, and the polynomial fitting equations corresponding to the multiple system degrees of freedom can be quickly determined.

[0142] In one embodiment, the vehicle data includes wheel slip angle, wheel camber angle and tire vertical force;

[0143] The tire lateral force is determined based on the wheel slip angle; and the friction torque is determined based on the wheel camber angle and the tire vertical force.

[0144] As an example, the vehicle data includes the wheel slip angle θ and wheel camber angle collected by the angle sensor set on each wheel. c , and obtain the tire vertical force collected by the force sensor set on each wheel F wz The vehicle controller can use the preset lateral force function to process the input parameter of the wheel slip angle θ to determine the corresponding tire lateral force F wyi (θ); accordingly, the on-board controller uses a preset friction torque function to adjust the wheel camber angle c and tire vertical force F wz These two input parameters are processed to determine the corresponding friction torque M wi ( c, F wz ) to realize the whole vehicle data collected by the sensor, dynamically determine the tire lateral force and friction torque corresponding to each wheel, so as to solve the dynamic equation based on the tire lateral force and friction torque determined by the whole vehicle data, and quickly determine the polynomial fitting equations corresponding to multiple system degrees of freedom.

[0145] In one embodiment, the shimmy dynamics model corresponding to the steering transmission system is determined based on a variable vector, a first-order derivative of the variable vector, a Jacobian matrix of the steering transmission system at an equilibrium point, and nonlinear multi-order terms corresponding to the variable vector;

[0146] The variable vector is determined based on a plurality of system degrees of freedom and a first-order derivative of a plurality of system degrees of freedom;

[0147] The nonlinear multi-terms are determined based on polynomial fitting equations corresponding to a plurality of system degrees of freedom.

[0148] As an example, the first vehicle data includes chassis data corresponding to the steering transmission system, the chassis data includes multiple system degrees of freedom related to the shimmy dynamics model, and the onboard controller can determine based on the multiple system degrees of freedom and the first-order derivatives of the multiple system degrees of freedom. For example, 9 system degrees of freedom are determined from the first vehicle data q k and the first-order derivatives corresponding to the 9 system degrees of freedom , based on 9 system degrees of freedom q k and its corresponding first-order derivative , determine the variable vector X ,Right now Then, based on the polynomial fitting equations corresponding to the 9 system degrees of freedom, the steering transmission system is determined at the equilibrium point X The Jacobian matrix J at 0 ( v ) and nonlinear multi-terms ; Finally, based on the variable vector X, the first-order derivative of the variable vector , Steering transmission system at the balance point X 0's Jacobian matrix J( v ) and nonlinear multi-terms , determine its corresponding swing dynamics model The steering transmission system here is at the balance point X 0's Jacobian matrix J( v ) can be understood as a polynomial fitting equation corresponding to multiple system degrees of freedom. In solving the equation, its relationship with the vehicle speed at the equilibrium point X0 is determined. v The associated Jacobian matrix J( v ). The nonlinear multi-term here It can be understood as the speed of the vehicle v Related vector containing variables X The nonlinear multi-terms can be specifically based on the 9 system degrees of freedom q k The constructed kinetic equation is fitted to determine the quadratic nonlinear multi-term or cubic nonlinear multi-term.

[0149] In one embodiment, the shimmy evaluation index is a dynamic stability index determined by performing a dynamic balance analysis on the shimmy dynamics model.

[0150] As an example, after determining the shimmy dynamics model corresponding to the steering transmission system, the on-board controller can perform a dynamic balance analysis on the shimmy dynamics model to obtain a dynamic stability index that reflects whether the dynamics of the steering transmission system is stable. The dynamic stability index can effectively reflect whether the vehicle has shimmy.

[0151] As an example, after determining the power stability index of the steering transmission system, the on-board controller may compare the power stability index with a preset threshold range; if the power stability index is within the preset threshold range, it means that the power of the steering transmission system is relatively stable, and the shimmy phenomenon that occurs is small, and it can be determined that it does not meet the multi-limit cycle shimmy condition; conversely, if the power stability index is not within the preset threshold range, it means that the power of the steering transmission system is unstable, and the shimmy phenomenon of the steering transmission system is more obvious, and there is a high probability that the multi-limit cycle shimmy phenomenon occurs, and it can be determined that it meets the multi-limit cycle shimmy condition.

[0152] In one embodiment, the dynamic stability index is the real part of the derivative of the characteristic root corresponding to the pure imaginary root of the Jacobian matrix at the critical vehicle speed with respect to the vehicle speed.

[0153] As an example, after determining the shimmy dynamics model corresponding to the steering transmission system, the on-board controller may calculate the Jacobian matrix J( v ) is derived to obtain the Jacobian matrix J( v )'s pure imaginary root ± oh The characteristic root corresponding to i M At critical speed v c Speed v The derivative of the Jacobian matrix is ​​determined by the real part of the derivative as the vibration evaluation index. In this example, the vehicle controller performs a derivative process on the Jacobian matrix to determine the Jacobian matrix J( v )'s pure imaginary root ± oh The characteristic root corresponding to i M At critical speed v c Speed v The derivative of is as follows:

[0154] ;

[0155] in, is the Jacobian matrix J( v )'s pure imaginary root ± oh The characteristic root corresponding to i M At critical speed v c Speed v The derivative of; critical speed vc for The speed of the vehicle at the time; X L 、X R are the Jacobian matrix J( v )'s pure imaginary root ± oh The first eigenvector and the second eigenvector corresponding to i, where the first eigenvector is a 1×18 eigenvector and the second eigenvector is a 18×1 eigenvector.

[0156] The preset threshold range may be a preset error range for evaluating whether a multi-limit cycle oscillation phenomenon occurs. The preset threshold range may be an error range close to 0 and may be represented by σ, for example, σ=0-10 -8 .

[0157] As an example, the vehicle controller determines the Jacobian matrix J( v )'s pure imaginary root ± oh The characteristic root corresponding to i M At critical speed v c Speed v The derivative of , then the real part of the derivative can be compared with the preset threshold range; if the real part of the derivative is within the preset threshold range, it means that the shimmy phenomenon of the steering transmission system is small, and it can be determined that it does not meet the multi-limit cycle shimmy condition; on the contrary, if the real part of the derivative is not within the preset threshold range, it means that the shimmy phenomenon of the steering transmission system is more obvious, and it is very likely that the multi-limit cycle shimmy phenomenon occurs, and it can be determined that it meets the multi-limit cycle shimmy condition.

[0158] In one embodiment, the vibration reduction adjustment mechanism 40 controlling the steering transmission system performs vibration reduction operation, including:

[0159] Controlling the vibration reduction adjustment mechanism 40 of the steering transmission system to perform vibration reduction operation based on the target parameter;

[0160] Wherein, the target parameter is determined based on the second vehicle data.

[0161] As an example, when the vehicle controller determines that the vehicle has a multi-limit cycle shimmy phenomenon when the first vehicle data satisfies the multi-limit cycle shimmy condition, it first dynamically determines the target parameters required to overcome the multi-limit cycle shimmy phenomenon based on the second vehicle data; controls the vibration reduction adjustment mechanism 40 of the steering transmission system to perform a vibration reduction operation based on the target parameters, specifically adjusting the variable parameters of the vibration reduction adjustment mechanism 40 on the rear axle rotation mechanism 30 to the target parameters to complete a vibration reduction operation. The second vehicle data here is data collected in real time for determining the target parameters.

[0162] In this example, after each vibration reduction operation is completed, the on-board controller can evaluate whether the multi-limit cycle shimmy condition is satisfied based on the re-collected first vehicle data. If satisfied, the vibration reduction operation needs to be performed again; otherwise, if not satisfied, it is determined that the multi-limit cycle shimmy of the steering transmission system disappears and there is no need to perform the vibration reduction operation again. For example, based on the re-collected first vehicle data, the Jacobian matrix J( v )'s pure imaginary root ± oh The characteristic root corresponding to i M At critical speed v cs Speed v The real part of the derivative of is , the critical speed here v cs For the s The critical speed of the steering transmission system calculated by the second optimization; the real part of the derivative is compared with the preset threshold range σ; if the real part of the derivative is not within the preset threshold range σ, it means that the shimmy phenomenon of the steering transmission system is more obvious, and there is a high probability that the multi-limit cycle shimmy phenomenon occurs, and the vibration reduction operation needs to be performed again; on the contrary, if the real part of the derivative is within the preset threshold range σ, then , it is determined that the shimmy phenomenon of the steering transmission system disappears and there is no need to perform the vibration reduction operation again.

[0163] In one embodiment, the vibration damping adjustment mechanism 40 includes a stiffness adjustment unit 41 disposed on the rear axle rotation mechanism 30;

[0164] The target parameters include a target stiffness.

[0165] As an example, the vehicle controller is connected to the stiffness adjustment unit 41. During the driving of the vehicle, when the vehicle evaluation determines that the multi-limit cycle oscillation phenomenon occurs based on the first vehicle data, the vehicle controller can dynamically determine the target stiffness based on the second vehicle data, and then control the stiffness adjustment unit 41 set on the rear axle rotation mechanism 30 to adjust the variable stiffness of the rear axle rotation mechanism 30 to reach the target stiffness that can slow down the multi-limit cycle oscillation phenomenon... and so on, until the multi-limit cycle oscillation phenomenon disappears, so as to avoid the multi-limit cycle oscillation phenomenon affecting the driving of the vehicle, thereby ensuring the driving safety and handling stability of the vehicle. In this example, the target stiffness is the stiffness that needs to be controlled by the stiffness adjustment unit 41 to adjust this time, specifically, the stiffness determined based on the first vehicle data for adjusting the stiffness of the rear axle rotation mechanism 30 (especially the rear axle steering straight tie rod 36) to achieve the stiffness of the vibration reduction effect.

[0166] In one embodiment, the second vehicle data includes vehicle speed;

[0167] The target stiffness is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a first vehicle speed interval to which the vehicle speed belongs.

[0168] As an example, when the vehicle controller determines that a vibration reduction operation is required, the vehicle speed may be obtained, and the vehicle speed may be compared with the lower speed threshold and the upper speed threshold corresponding to different first speed intervals to determine the first speed interval to which the vehicle speed interval belongs; and then the polynomial fitting coefficient corresponding to the first speed interval is obtained. A ci , B ci , C ci and D ci , then, based on the vehicle speed v and the polynomial fitting coefficient corresponding to the first vehicle speed interval A ci , B ci , C ci and D ci , determine the target stiffness as follows:

[0169] ;

[0170] in, v is the vehicle speed, c z2 ( v ) is the target stiffness of the rear axle steering tie rod 36, A ci , B ci , C ci and D ci are the polynomial fitting coefficients of the stiffness-velocity equation, v c(j-1) and v cj For the i A lower speed threshold and an upper speed threshold for a first speed interval.

[0171] In one embodiment, the vibration reduction adjustment mechanism 40 further includes a damping adjustment unit 42 disposed on the front axle rotation mechanism 20;

[0172] The target parameters include target damping.

[0173] As an example, the vehicle controller is connected to the damping adjustment unit 42. During the driving of the vehicle, when the vehicle evaluation determines that the multi-limit cycle oscillation phenomenon occurs based on the first vehicle data, the vehicle controller can dynamically determine the target damping based on the second vehicle data, and then control the damping adjustment unit 42 set on the front axle rotation mechanism 20 to adjust the variable damping of the front axle rotation mechanism 20 to achieve the target damping that can slow down the multi-limit cycle oscillation phenomenon... and so on, until the multi-limit cycle oscillation phenomenon disappears, so as to avoid the multi-limit cycle oscillation phenomenon affecting the driving of the vehicle, thereby ensuring the driving safety and handling stability of the vehicle. In this example, the target damping is the damping that needs to be controlled by the damping adjustment unit 42 to adjust this time, specifically the damping determined based on the first vehicle data for adjusting the front axle rotation mechanism 20 (especially the front axle steering tie rod 22) to achieve the damping effect.

[0174] In one embodiment, the second vehicle data includes vehicle speed;

[0175] The target damping is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a second vehicle speed interval to which the vehicle speed belongs.

[0176] As an example, when the vehicle controller determines that a vibration reduction operation is required, it needs to first obtain the vehicle speed, and can compare the vehicle speed with the lower speed threshold and the upper speed threshold corresponding to different second speed intervals to determine the second speed interval to which the vehicle speed interval belongs; then obtain the polynomial fitting coefficient corresponding to the second speed interval A di , B di , C di and D di , then, based on the vehicle speed v and the polynomial fitting coefficient corresponding to the second vehicle speed interval A di , B di , C di and D di , determine the target damping as follows:

[0177] ;

[0178] in, v is the vehicle speed, d h1 ( v ) is the target damping of the front axle steering tie rod 22, A di , Bdi , C di and D di are the polynomial fitting coefficients of the damping-velocity equation, v d(j-1) and v d(j+1) For the i A lower speed threshold and an upper speed threshold for a second speed interval.

[0179] In this example, the polynomial fitting coefficients are coefficients determined based on the polynomial fitting equations corresponding to the plurality of system degrees of freedom. For example, the polynomial fitting coefficients are determined based on the first point set ( v i , c z2 ( v i )) and the second point set ( v j , d h1 ( v j ))Sure, v i is the first speed, c z2 ( v i ) is a target stiffness determined based on the first vehicle speed, specifically a target stiffness determined by calculating dynamic equations corresponding to a plurality of system degrees of freedom based on the first vehicle speed; v j is the second speed, d h1 ( v j ) is a target damping determined based on the second vehicle speed, specifically, a target damping determined by calculating the dynamic equations corresponding to a plurality of system degrees of freedom based on the second vehicle speed; the first point set ( v i , c z2 ( v i )) and the second point set ( v j , d h1 ( v j )) satisfies the following formula:

[0180] ;

[0181] in, and are the polynomial fitting coefficients in the same point set, corresponding to A, B, C and D in the above formula respectively. is the result of analyzing the polynomial fitting coefficients in the first set of points, The result of analyzing the polynomial fitting coefficients in the second point set is and When a preset condition is met (for example, less than a preset threshold), it can be determined that the fitting of the polynomial fitting coefficients is completed.

[0182] In this embodiment, when the steering transmission system exhibits multi-limit cycle oscillation, bifurcation may occur in a plurality of different vehicle speed intervals. Therefore, during the vibration reduction operation of the damping adjustment unit 42 and / or the stiffness adjustment unit 41, it is necessary to first determine the corresponding first vehicle speed interval and / or second vehicle speed interval according to the vehicle speed, and dynamically determine the corresponding target stiffness and / or target damping based on the polynomial fitting coefficients corresponding to the first vehicle speed interval and / or the second vehicle speed interval in combination with the vehicle speed, thereby achieving effective vibration reduction in a plurality of vehicle speed intervals and ensuring the vibration reduction effect.

[0183] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0184] In one embodiment, a steering system is provided, comprising a steering input mechanism 10, a steering output mechanism and the steering transmission system in the above embodiment;

[0185] The steering input mechanism 10 is connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30;

[0186] The steering output mechanism is connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 .

[0187] As an example, the steering system includes a steering input mechanism 10, a steering output mechanism and a steering transmission system, and the steering transmission system includes a front axle rotation mechanism 20, a rear axle rotation mechanism 30 and a vibration reduction adjustment mechanism 40. The steering input mechanism 10 is connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 for transmitting power; the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 are connected to the steering output mechanism for controlling the steering output mechanism to steer. Since the rear axle rotation mechanism 30 is provided with the vibration reduction adjustment mechanism 40, when the vehicle is evaluated to have a multi-limit cycle shimmy phenomenon based on the first vehicle data, the vibration reduction adjustment mechanism 40 can be controlled to adjust its variable parameters to target parameters until the multi-limit cycle shimmy phenomenon disappears, so as to avoid the multi-limit cycle shimmy phenomenon affecting the vehicle driving, thereby ensuring the vehicle driving safety and handling stability.

[0188] In one embodiment, the steering system further includes a transmission mechanism 50 , which is suitable for connecting to the steering input mechanism 10 and connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 .

[0189] As an example, the steering system also includes the transmission mechanism 50, which is suitable for being installed on the vehicle body assembly, and is connected to the steering input mechanism 10 for receiving power from the steering input mechanism 10; and the transmission mechanism 50 is also connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, and can transmit power to different steering output mechanisms through the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, so that when the driver operates the steering input mechanism 10, the front axle wheels and the rear axle wheels can be controlled to rotate in both directions.

[0190] In one embodiment, the steering input mechanism 10 includes a steering wheel 11, a steering motor and a steering control module;

[0191] The steering wheel 11 is connected to the transmission mechanism 50;

[0192] The steering motor is connected to the steering wheel 11;

[0193] The steering control module is connected to the steering motor.

[0194] As an example, the steering input mechanism 10 includes a steering wheel, a steering motor and a steering control module. The steering wheel 11 is connected to the transmission mechanism 50 through a steering gear 12. A user can operate the steering wheel for steering control so that the transmission mechanism 50 transmits power to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30; the steering motor is connected to the steering wheel, and the steering motor is connected to the steering control module through a connecting harness. The steering control module can control the steering of the steering wheel according to user operation, and then transmit power to the transmission mechanism 50; or, based on an intelligent control system, intelligent control of the steering wheel is realized, and then power is transmitted to the transmission mechanism 50.

[0195] like Figure 1 As shown, the steering input mechanism 10 includes a steering wheel 11 and a steering gear 12 connected to the steering wheel 11, and the steering gear 12 is connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30 through the transmission mechanism 50, so that the front axle rotation mechanism 20 drives the two front axle wheels to rotate, and the rear axle rotation mechanism 30 drives the two rear axle wheels to rotate, so as to achieve the purpose of dual steering control.

[0196] In one embodiment, the steering output mechanism includes a left front wheel 62, a right front wheel 61, a left rear wheel 64 and a right rear wheel 63;

[0197] The front axle rotation mechanism 20 is connected to the left front wheel 62 and the right front wheel 61;

[0198] The rear axle rotation mechanism 30 is connected to the left rear wheel 64 and the right rear wheel 63 .

[0199] As an example, the steering output mechanism includes a left front wheel 62, a right front wheel 61, a left rear wheel 64 and a right rear wheel 63; the front axle rotation mechanism 20 is connected to the left front wheel 62 and the right front wheel 61, and is used to control the rotation of the two front axle wheels. The rear axle rotation mechanism 30 is connected to the left front wheel 62 and the right front wheel 61, and is used to control the rotation of the two rear axle wheels. The transmission mechanism 50 is installed on the vehicle body assembly, and the transmission mechanism 50 is connected to the steering input mechanism 10, and is connected to the front axle rotation mechanism 20 and the rear axle rotation mechanism 30, and is used to transmit power. That is, the steering input mechanism 10 is connected to the front axle rotation mechanism 20 through the transmission mechanism 50, and is connected to the rear axle rotation mechanism 30 through the transmission mechanism 50, so that when the driver operates the steering input mechanism 10, the front axle wheels and the rear axle wheels can be controlled to rotate in both directions.

[0200] In one embodiment, a vehicle-mounted controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steering transmission control method in the above embodiment is implemented, for example Figure 2 S201-S202 shown are not described here again to avoid repetition.

[0201] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steering transmission control method in the above embodiment is implemented, for example Figure 2 S201-S202 shown are not described here again to avoid repetition.

[0202] In one embodiment, a vehicle is provided, comprising the above-mentioned steering transmission system, or the above-mentioned steering system, or the above-mentioned on-board controller, or the above-mentioned computer-readable storage medium.

[0203] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0204] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0205] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A steering transmission system, characterized in that: It includes a front axle rotating mechanism, a rear axle rotating mechanism and a vibration reduction adjustment mechanism; One end of the front axle rotating mechanism and the rear axle rotating mechanism is suitable for connecting to a steering input mechanism, and the front axle rotating mechanism comprises a front axle steering tie rod; The other ends of the front axle rotating mechanism and the rear axle rotating mechanism are suitable for connecting different steering output mechanisms; the rear axle rotating mechanism includes a rear axle steering straight tie rod; The vibration damping adjustment mechanism comprises a stiffness adjustment unit arranged on the rear axle rotation mechanism, and the stiffness adjustment unit is arranged on the rear axle steering straight tie rod; The vibration reduction adjustment mechanism further includes a damping adjustment unit arranged on the front axle rotation mechanism, and the damping adjustment unit is arranged on the front axle steering tie rod.

2. The steering transmission system according to claim 1, characterized in that: The damping adjustment unit includes a magnetorheological shock absorber, an oil shock absorber or a magnetic resistance shock absorber.

3. The steering transmission system according to claim 1, characterized in that: The stiffness adjustment unit includes an air spring, a hydraulic cylinder or an electromagnetic solenoid.

4. The steering transmission system according to claim 1, characterized in that: The steering transmission system further comprises a transmission mechanism, which is used to be connected to the steering input mechanism and to be connected to the front axle rotation mechanism and the rear axle rotation mechanism.

5. A steering transmission control method, characterized in that: include: Acquiring first vehicle data; When the first vehicle data satisfies a multi-limit cycle shimmy condition, controlling a vibration reduction adjustment mechanism of the steering transmission system to perform a vibration reduction operation; Wherein, the steering transmission system is the steering transmission system according to any one of claims 1 to 4.

6. The steering transmission control method according to claim 5, characterized in that: After acquiring the first vehicle data, the steering transmission control method further includes: Determining a shimmy evaluation index corresponding to the shimmy dynamics model based on a shimmy dynamics model corresponding to the steering transmission system, wherein the shimmy dynamics model is determined based on the first vehicle data; If the shimmy evaluation index is not within a preset threshold range, it is determined that the first vehicle data satisfies a multi-limit cycle shimmy condition.

7. The steering transmission control method according to claim 6, characterized in that: The shimmy dynamics model is determined based on polynomial fitting equations corresponding to a plurality of system degrees of freedom; The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the first vehicle data, and the system degrees of freedom are free variables in the shimmy dynamics model.

8. The steering transmission control method according to claim 7, characterized in that: The first vehicle data includes chassis data and vehicle data corresponding to the steering transmission system; The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom and the vehicle data; The dynamic equations corresponding to the plurality of system degrees of freedom are determined based on chassis data corresponding to the steering transmission system.

9. The steering transmission control method according to claim 8, characterized in that: The polynomial fitting equations corresponding to the plurality of system degrees of freedom are determined based on the dynamic equations corresponding to the plurality of system degrees of freedom, the tire lateral force and the friction torque; The tire lateral force and the friction torque are determined based on the whole vehicle data.

10. The steering transmission control method according to claim 9, characterized in that: The vehicle data includes wheel slip angle, wheel camber angle and tire vertical force; The tire lateral force is determined based on the wheel slip angle; and the friction torque is determined based on the wheel camber angle and the tire vertical force.

11. The steering transmission control method according to claim 7, characterized in that: The shimmy dynamics model corresponding to the steering transmission system is determined based on a variable vector, a first-order derivative of the variable vector, a Jacobian matrix of the steering transmission system at an equilibrium point, and nonlinear multi-order terms corresponding to the variable vector; The variable vector is determined based on a plurality of system degrees of freedom and a first-order derivative of a plurality of system degrees of freedom; The nonlinear multi-terms are determined based on polynomial fitting equations corresponding to the plurality of system degrees of freedom.

12. The steering transmission control method according to claim 11, characterized in that: The shimmy evaluation index is a dynamic stability index determined by performing a dynamic balance analysis on the shimmy dynamics model.

13. The steering transmission control method according to claim 12, characterized in that: The dynamic stability index is the real part of the derivative of the characteristic root corresponding to the pure imaginary root of the Jacobian matrix at the critical vehicle speed with respect to the vehicle speed.

14. The steering transmission control method according to claim 5, characterized in that: The vibration reduction adjustment mechanism of the steering transmission system is controlled to perform vibration reduction operation, including: Controlling the vibration reduction adjustment mechanism of the steering transmission system to perform vibration reduction operation based on target parameters; The target parameter is determined based on second vehicle data.

15. The steering transmission control method according to claim 14, characterized in that: The vibration damping adjustment mechanism includes a stiffness adjustment unit arranged on the rear axle rotation mechanism; The target parameters include a target stiffness.

16. The steering transmission control method according to claim 15, characterized in that: The second vehicle data includes vehicle speed; The target stiffness is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a first vehicle speed interval to which the vehicle speed belongs.

17. The steering transmission control method according to claim 15, characterized in that: The vibration reduction adjustment mechanism further includes a damping adjustment unit arranged on the front axle rotation mechanism; The target parameters include target damping.

18. The steering transmission control method according to claim 17, characterized in that: The second vehicle data includes vehicle speed; The target damping is determined based on the vehicle speed and a plurality of polynomial fitting coefficients corresponding to a second vehicle speed interval to which the vehicle speed belongs.

19. A steering system, characterized in that: It comprises a steering input mechanism, a steering output mechanism and a steering transmission system according to any one of claims 1 to 3; The steering input mechanism is connected to the front axle rotation mechanism and the rear axle rotation mechanism; The steering output mechanism is connected to the front axle rotation mechanism and the rear axle rotation mechanism.

20. The steering system according to claim 19, characterized in that The steering system further comprises a transmission mechanism, which is connected to the steering input mechanism and to the front axle rotation mechanism and the rear axle rotation mechanism.

21. The steering system according to claim 20, characterized in that The steering input mechanism includes a steering wheel, a steering motor and a steering control module; The steering wheel is connected to the transmission mechanism; The steering motor is connected to the steering wheel and is used to control the rotation of the steering wheel.

22. The steering system according to claim 20, characterized in that The steering output mechanism includes a left front wheel, a right front wheel, a left rear wheel and a right rear wheel; The front axle rotating mechanism is connected to the left front wheel and the right front wheel; The rear axle rotation mechanism is connected to the left rear wheel and the right rear wheel.

23. A vehicle-mounted controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steering transmission control method according to any one of claims 5 to 18 is implemented.

24. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steering transmission control method according to any one of claims 5 to 18 is implemented.

25. A vehicle, characterized in that: It comprises the steering transmission system according to any one of claims 1 to 4, or the steering system according to any one of claims 19 to 22, or the on-board controller according to claim 23, or the computer-readable storage medium according to claim 24.

Images