Force feedback method, device, vehicle and medium for a steer-by-wire system

Abstract

The present disclosure relates to the technical field of vehicles, in particular to a force feedback method and device of a steer-by-wire system, a vehicle and a medium. The method comprises: obtaining a steering wheel speed, a steering wheel angle and a vehicle speed; determining a steering wheel rotation direction according to the steering wheel speed, and determining a corresponding first basic force according to the steering wheel rotation direction and the steering wheel angle; determining a corresponding first ratio according to the vehicle speed, the first ratio being inversely proportional to the vehicle speed; determining a first feedback torque according to the first basic force and the first ratio; and performing force feedback on the steering wheel according to the first feedback torque. The present disclosure can provide stable hand force feedback for the driver and has stronger robustness.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, and more particularly to a force feedback method, device, vehicle, and medium for a steer-by-wire system. Background Technology

[0002] The development of steer-by-wire technology has enabled the mechanical decoupling of the vehicle's steering wheel from the steering actuator. The steer-by-wire system eliminates the mechanical connection between the steering wheel and the steering actuator, achieving steering function through steer-by-wire. Specifically, sensors detect the steering wheel's rotation angle and transmit it to the Electronic Control Unit (ECU). The ECU then sends commands to the steering actuator, which executes the steering action according to the commands.

[0003] Because the steering wheel lacks the mechanical connection with the steering actuator to transmit force, the driver lacks tactile feedback when operating the steering wheel, and therefore cannot perceive the vehicle's status through tactile feedback, which in turn leads to a decrease in vehicle handling and the driver's sense of security. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this disclosure provides a force feedback method, device, vehicle, and medium for a steer-by-wire system.

[0005] According to a first aspect of the present disclosure, a force feedback method for a steer-by-wire system is provided, comprising:

[0006] Get steering wheel speed, steering wheel angle, and vehicle speed;

[0007] The steering wheel rotation direction is determined based on the steering wheel rotation speed, and the corresponding first basic force is determined based on the steering wheel rotation direction and the steering wheel angle.

[0008] A first ratio is determined based on the vehicle speed, and the first ratio is inversely proportional to the vehicle speed;

[0009] The first feedback torque is determined based on the first basic force and the first ratio.

[0010] Force feedback is applied to the steering wheel based on the first feedback torque.

[0011] Optionally, the method further includes:

[0012] Obtain the rack rotation speed and calculate the rack friction force based on the rack rotation speed;

[0013] The second feedback torque is determined based on the rack friction force and the preset second ratio.

[0014] The step of providing force feedback to the steering wheel based on the first feedback torque includes:

[0015] Force feedback is provided to the steering wheel based on the first feedback torque and the second feedback torque.

[0016] Optionally, calculating the rack friction force based on the rack rotation speed includes:

[0017] The rack friction force is calculated using the following formula:

[0018]

[0019]

[0020]

[0021] Where V is the rotational speed of the rack, and Z is the average deflection of the rack. Let be the first derivative of Z, σ0 be the total stiffness of the rack, σ1 be the damping coefficient of the rack, σ2 be the viscous friction coefficient of the rack, and F be the first derivative of Z. C F is the kinetic friction force of the rack. S V is the static friction force of the rack. S Let G(V) be a preset sliding speed, and F be a preset function of the rack rotation speed. L (V,Z) represents the frictional force of the rack.

[0022] Optionally, the method further includes:

[0023] The rack force is acquired and filtered to obtain a high-frequency rack force;

[0024] A third ratio is determined based on the road feel intensity level set by the user, and the third ratio is proportional to the road feel intensity level.

[0025] The third feedback torque is determined based on the high-frequency rack force and the third ratio.

[0026] The step of providing force feedback to the steering wheel based on the first feedback torque includes:

[0027] Force feedback is provided to the steering wheel based on the first feedback torque and the third feedback torque.

[0028] Optionally, the method further includes:

[0029] The rack force is acquired and filtered to obtain the high-frequency rack force and the low-frequency rack force;

[0030] A third ratio is determined based on the road feel intensity level set by the user, and the third ratio is proportional to the road feel intensity level.

[0031] The target gain is determined based on the low-frequency rack force and the vehicle speed, wherein the target gain is proportional to the low-frequency rack force and the vehicle speed, respectively.

[0032] The third feedback torque is determined based on the high-frequency rack force, the third ratio, and the target gain;

[0033] The step of providing force feedback to the steering wheel based on the first feedback torque includes:

[0034] Force feedback is provided to the steering wheel based on the first feedback torque and the third feedback torque.

[0035] According to a second aspect of the present disclosure, a force feedback device for a steer-by-wire system is provided, comprising:

[0036] The data acquisition module is used to acquire steering wheel speed, steering wheel angle, and vehicle speed;

[0037] The first torque determination module is used to determine the steering wheel rotation direction based on the steering wheel rotation speed, and to determine the corresponding first basic force based on the steering wheel rotation direction and the steering wheel angle. It is also used to determine the corresponding first ratio based on the vehicle speed, the first ratio being inversely proportional to the vehicle speed. Furthermore, it is used to determine the first feedback torque based on the first basic force and the first ratio.

[0038] The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque.

[0039] Optionally, the device further includes:

[0040] The second torque determination module is used to obtain the rack rotation speed and calculate the rack friction force based on the rack rotation speed, and determine the second feedback torque based on the rack friction force and a preset second ratio.

[0041] The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque and the second feedback torque.

[0042] Optionally, the device further includes:

[0043] A filtering module is used to acquire rack force and filter rack force to obtain high-frequency rack force and low-frequency rack force;

[0044] The third torque determination module is used to determine a corresponding third ratio based on the road feel intensity level set by the user. The third ratio is proportional to the road feel intensity level. It is also used to determine a target gain based on the low-frequency rack force and the vehicle speed. The target gain is proportional to the low-frequency rack force and the vehicle speed, respectively. It is also used to determine a third feedback torque based on the high-frequency rack force, the third ratio, and the target gain.

[0045] The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque and the third feedback torque.

[0046] According to a third aspect of the present disclosure, a vehicle is provided, including a steer-by-wire system, the steer-by-wire system including a steering wheel, a steering actuator, and a processor, the processor being configured to perform a force feedback method for the steer-by-wire system provided in the first aspect of the present disclosure.

[0047] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement the force feedback method of the steer-by-wire system provided in the first aspect of the present disclosure.

[0048] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0049] This disclosure calculates the first feedback torque based on the steering wheel speed, steering wheel angle, and vehicle speed, and provides force feedback to the steering wheel based on the first feedback torque, thereby providing steering feel feedback to the driver. This allows the driver to perceive the vehicle's steering status through the steering feel, improving driving safety. Moreover, the first feedback torque is not affected by high / low surface friction, and can provide stable hand force feedback to the driver regardless of the road surface, making it more robust.

[0050] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0051] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0052] Figure 1 This is a flowchart illustrating a force feedback method for a steer-by-wire system according to an exemplary embodiment.

[0053] Figure 2 This is a schematic diagram illustrating the rack force variation under different steering wheel rotation directions according to an exemplary embodiment.

[0054] Figure 3 This is a schematic diagram illustrating the determination of a first feedback torque according to an exemplary embodiment.

[0055] Figure 4 This is a schematic diagram illustrating the determination of a third feedback torque according to an exemplary embodiment.

[0056] Figure 5This is a schematic diagram of a force feedback device for a steer-by-wire system according to an exemplary embodiment. Detailed Implementation

[0057] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0058] It should be noted that all actions involving the acquisition of signals, information, or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where the application is located, and with the authorization granted by the owner of the relevant device.

[0059] In view of the technical problems existing in the background art, the present disclosure provides a force feedback method for a steer-by-wire system, which can provide the driver with corresponding hand force feedback, including hand feel and road feel feedback, to improve driving safety. In related technologies, the feedback torque is generally obtained by using an inverse power assist curve based on the rack force of the steer-by-wire system. However, the rack force is strongly correlated with the road surface adhesion coefficient. On high adhesion coefficient roads, such as dry and clean asphalt roads, the obtained hand force is larger, while on low adhesion coefficient roads, such as wet, waterlogged, or snow-covered roads, the obtained hand force is smaller. Therefore, the hand force obtained in this way is easily affected by high / low adhesion road surfaces.

[0060] Figure 1 This is a flowchart illustrating a force feedback method for a steer-by-wire system according to an exemplary embodiment. (Refer to...) Figure 1 The force feedback method of the steer-by-wire system may include steps S101 to S105.

[0061] In step S101, the steering wheel speed, steering wheel angle, and vehicle speed are obtained.

[0062] For example, the system receives data from sensors, such as steering wheel rotation speed, steering wheel angle, and vehicle speed.

[0063] In step S102, the steering wheel rotation direction is determined based on the steering wheel speed, and the corresponding first basic force is determined based on the steering wheel rotation direction and steering wheel angle.

[0064] For example, first, the direction of steering wheel rotation is determined based on the steering wheel speed, such as determining whether the steering wheel rotates from right to left or from left to right. Then, based on the direction of steering wheel rotation and the steering wheel angle, and according to a first mapping relationship between the direction of steering wheel rotation, the steering wheel angle, and a first basic force, the corresponding first basic force is determined. This first mapping relationship describes the first basic force corresponding to different steering wheel rotation directions and different steering wheel angles.

[0065] In step S103, a first ratio is determined based on the vehicle speed, and this first ratio is inversely proportional to the vehicle speed.

[0066] For example, based on the vehicle speed, a corresponding first ratio is determined according to a second mapping relationship between the vehicle speed and the first ratio. In this second mapping relationship, the vehicle speed is inversely proportional to the first ratio, that is, the higher the vehicle speed, the smaller the first ratio.

[0067] It should be noted that steps S102 and S103 can be executed simultaneously or sequentially, and this disclosure does not limit the execution order of the two.

[0068] In step S104, the first feedback torque is determined based on the first basic force and the first ratio.

[0069] For example, the first basic force is multiplied by the first ratio to obtain the first feedback torque.

[0070] In step S105, force feedback is applied to the steering wheel based on the first feedback torque.

[0071] For example, after determining the first feedback torque, the road feel motor is controlled to generate the same torque as the first feedback torque. The torque generated by the road feel motor is transmitted to the steering wheel, thereby providing steering feel feedback to the driver.

[0072] In some embodiments, to achieve the above process, a first mapping relationship between the steering wheel rotation direction, the steering wheel angle, and the first basic force is preset, as well as a second mapping relationship between the vehicle speed and the first ratio is preset. The first mapping relationship can be set based on the rack force variation curve under different steering wheel rotation directions.

[0073] Figure 2 This is a schematic diagram illustrating the rack force variation under different steering wheel rotation directions according to an exemplary embodiment. The upper curve represents the rack force variation curve when the steering wheel is turned from left to right to the end, and the lower curve represents the rack force variation curve when the steering wheel is turned from right to left to the end. Figure 2It can be seen that the rack force corresponding to the same steering wheel angle may vary under different steering wheel rotation directions. Moreover, when turning the steering wheel to the end, the larger the steering wheel angle, the greater the rack force (the larger the absolute value of the rack force). When turning the steering wheel to the center position, the rack force changes very little.

[0074] Based on the characteristics of the rack force variation, a first mapping relationship is established between the steering wheel rotation direction, steering wheel angle, and the first basic force.

[0075] In some embodiments, the first mapping relationship can be any possible form such as a surface, curve, or table.

[0076] In some embodiments, the first mapping relationship is preset in the processor.

[0077] In some embodiments, the second mapping relationship can be any possible form such as a function, curve, or table.

[0078] In some embodiments, the second mapping relationship is preset in the processor.

[0079] Figure 3 This is a schematic diagram illustrating the determination of a first feedback torque according to an exemplary embodiment. (Refer to...) Figure 3 When determining the first feedback torque, the steering wheel speed, steering wheel angle, and vehicle speed are first obtained. The steering wheel rotation direction is determined based on the steering wheel speed. Based on the steering wheel rotation direction and steering wheel angle, the corresponding first basic force is determined based on the first mapping relationship. Based on the vehicle speed, the corresponding first ratio is determined based on the second mapping relationship. Then, the first basic force and the first ratio are multiplied to obtain the first feedback torque.

[0080] It should be noted that, compared with the rack force and reverse assist curve in related technologies, the first feedback torque in this disclosure is calculated based on the steering wheel speed, steering wheel angle and vehicle speed, and is not affected by high / low surface friction. It can obtain stable hand force regardless of the road surface, so the hand feel feedback is more stable and robust.

[0081] Furthermore, in some embodiments, the force feedback method of the steer-by-wire system further includes: acquiring the rack rotation speed and calculating the rack friction force based on the rack rotation speed, and determining a second feedback torque based on the rack friction force and a preset second ratio. For example, the second feedback torque is obtained by multiplying the rack friction force by the second ratio.

[0082] Therefore, in step S105, force feedback is applied to the steering wheel based on the first feedback torque and the second feedback torque.

[0083] For example, after determining the first feedback torque and the second feedback torque, the first feedback torque and the second feedback torque are superimposed to obtain the total feedback torque. The road feel motor is controlled to generate the same torque as the total feedback torque. The torque generated by the road feel motor is transmitted to the steering wheel, thereby providing steering feel feedback to the driver.

[0084] Understandably, by adding a second feedback torque, the feedback feel becomes more realistic, simulating the feel of a traditional mechanical steering system.

[0085] In some embodiments, the rack friction force can be calculated using the following formula:

[0086]

[0087]

[0088]

[0089] Where V is the rack rotational speed and Z is the average deflection of the rack. Let be the first derivative of Z, σ0 be the total stiffness of the rack, σ1 be the damping coefficient of the rack, σ2 be the viscous friction coefficient of the rack, and F be the first derivative of Z. C F is the kinetic friction force of the rack. S V is the static friction force of the rack. S V is the preset sliding speed. S It is a very small slip velocity, G(V) is a preset function of the rack rotation speed, and F L (V,Z) represents the frictional force of the rack.

[0090] For example, before calculating the rack friction, first determine the total stiffness σ0, damping coefficient σ1, viscous friction coefficient σ2, and dynamic friction force F of the rack in the steer-by-wire system. C Static friction force F S and the preset sliding speed V S .

[0091] In one example, the values ​​of the above parameters can be as shown in Table 1.

[0092] Table 1

[0093]

[0094] Substitute the values ​​of each parameter in Table 1 into Equations 1 and 2, and calculate Z and Z based on the rack rotation speed V. The rack friction force F was then obtained using Equation 3. L (V,Z).

[0095] Furthermore, in some embodiments, step S105 may also provide force feedback to the steering wheel based on the first feedback torque and the third feedback torque.

[0096] In one implementation, the third feedback torque can be determined through the following steps: acquiring the rack force and filtering it to obtain a high-frequency rack force; determining the corresponding third ratio based on the user-set road feel intensity level; and determining the third feedback torque based on the high-frequency rack force and the third ratio. For example, the high-frequency rack force can be multiplied by the third ratio to obtain the third feedback torque.

[0097] For example, users can set the road feel intensity level based on their own needs. If they want a stronger road feel feedback, they can set a higher road feel intensity level, and vice versa.

[0098] For example, based on the road feel intensity level set by the user, and based on the third mapping relationship between the road feel intensity level and the third ratio, the corresponding third ratio is determined. The third ratio is directly proportional to the road feel intensity level. The higher the road feel intensity level is set, the stronger the road feel feedback the user expects, and the larger the third ratio will be.

[0099] In some embodiments, the third mapping relationship can be any possible form such as a function, curve, or table.

[0100] In some embodiments, the third mapping relationship is preset in the processor.

[0101] After determining the first feedback torque and the third feedback torque, the first feedback torque and the third feedback torque are superimposed to obtain the total feedback torque. The road feel motor is controlled to generate the same torque as the total feedback torque. The torque generated by the road feel motor is transmitted to the steering wheel, thereby providing the driver with steering feel and road feel feedback.

[0102] In the above technical solution, the required third feedback torque is determined based on the user-set road feel intensity level and the high-frequency component of the rack force. Force feedback is then applied to the steering wheel based on the first and third feedback torques, thereby providing road feel feedback to the driver. Furthermore, the third feedback torque can be flexibly adjusted based on the road feel intensity level, thus providing customized hand force feedback to the driver.

[0103] In some embodiments, when the user does not set the road feel intensity level, the corresponding third ratio can be zero, and the resulting third feedback torque is also zero. Therefore, in this case, only the first feedback torque is used for tactile feedback, without including road feel feedback.

[0104] In other embodiments, the third feedback torque can be determined through the following steps: acquiring and filtering the rack force to obtain high-frequency and low-frequency rack forces; determining a corresponding third ratio based on the user-set road feel intensity level; determining a target gain based on the low-frequency rack force and vehicle speed; and determining the third feedback torque based on the high-frequency rack force, the third ratio, and the target gain. The third ratio is proportional to the road feel intensity level, and the target gain is proportional to both the low-frequency rack force and the vehicle speed.

[0105] For example, based on the road feel intensity level set by the user, and based on the third mapping relationship between the road feel intensity level and the third ratio, the corresponding third ratio is determined. The third ratio is directly proportional to the road feel intensity level. The higher the road feel intensity level is set, the stronger the road feel feedback the user expects, and the larger the third ratio will be.

[0106] For example, based on the low-frequency rack force and vehicle speed, a fourth mapping relationship is established between the low-frequency rack force, vehicle speed, and target gain to determine the corresponding target gain. The target gain is proportional to both the low-frequency rack force and vehicle speed. This fourth mapping relationship describes the target gain for different low-frequency rack forces and different vehicle speeds. With a fixed low-frequency rack force, the higher the vehicle speed, the greater the target gain; conversely, with a fixed vehicle speed, the greater the low-frequency rack force, the greater the target gain.

[0107] In some embodiments, the fourth mapping relationship can be any possible form such as a surface or a table.

[0108] In some embodiments, the fourth mapping relationship is preset in the processor.

[0109] In the above technical solution, the third ratio is determined based on the road feel intensity level set by the user, the required target gain is determined based on the low-frequency part of the rack force, and the required third feedback torque is determined based on the third ratio, the target gain, and the high-frequency part of the rack force. On the one hand, the third feedback torque can be flexibly adjusted based on the road feel intensity level, which can provide customized hand force feedback for the driver. On the other hand, the gain control of the third feedback torque based on the low-frequency part of the rack force can obtain more realistic road feel feedback.

[0110] Figure 4 This is a schematic diagram illustrating the determination of a third feedback torque according to an exemplary embodiment. (Refer to...) Figure 4 When determining the third feedback torque, the rack force is first acquired and filtered to obtain the high-frequency rack force and the low-frequency rack force. Based on the road feel intensity level set by the user, the corresponding third ratio is determined based on the third mapping relationship. Based on the low-frequency rack force and the vehicle speed, the target gain is determined based on the fourth mapping relationship. Then, the third ratio, the target gain and the high-frequency rack force are multiplied to obtain the third feedback torque.

[0111] In some embodiments, rack force can be acquired by a sensor.

[0112] In some embodiments, the rack force can be estimated. For example, the output torque of the steering actuator motor is calculated, and the rack force is estimated based on this output torque and the gear ratio from the steering actuator motor to the rack.

[0113]

[0114] Specifically, the three-phase current of the steering actuator motor can be collected by sensors and then converted into D / Q axis current. The D / Q axis inductance, reluctance, and back electromotive force are obtained during motor calibration, and the number of pole pairs is derived from the motor design. The output torque is multiplied by the transmission ratio from the motor to the rack to obtain the rack force.

[0115] In some embodiments, rack force may also be obtained using other existing methods, which are not limited in this disclosure.

[0116] According to the force feedback method of the steer-by-wire system provided in this disclosure, in one specific embodiment, a first feedback torque is determined based on the steering wheel rotation speed, steering wheel angle and vehicle speed, a second feedback torque is determined based on the rack rotation speed, a third feedback torque is determined based on the rack force, road feel intensity level and vehicle speed, and finally, force feedback is applied to the steering wheel based at least on the first feedback torque.

[0117] In some embodiments, force feedback is applied to the steering wheel based on a first feedback torque.

[0118] In some embodiments, force feedback is provided to the steering wheel based on a first feedback torque and a second feedback torque.

[0119] In some embodiments, force feedback is provided to the steering wheel based on a first feedback torque and a third feedback torque.

[0120] In some embodiments, force feedback is provided to the steering wheel based on a first feedback torque, a second feedback torque, and a third feedback torque.

[0121] Figure 5 This is a schematic diagram illustrating a force feedback device for a steer-by-wire system according to an exemplary embodiment. (Refer to...) Figure 5 The force feedback device 500 of the steer-by-wire system includes:

[0122] The data acquisition module 501 is used to acquire steering wheel speed, steering wheel angle and vehicle speed;

[0123] The first torque determination module 502 is used to determine the steering wheel rotation direction based on the steering wheel rotation speed, and to determine the corresponding first basic force based on the steering wheel rotation direction and the steering wheel angle. It is also used to determine the corresponding first ratio based on the vehicle speed, wherein the first ratio is inversely proportional to the vehicle speed. Furthermore, it is used to determine the first feedback torque based on the first basic force and the first ratio.

[0124] The force feedback module 503 is used to provide force feedback to the steering wheel based on the first feedback torque.

[0125] Optionally, the force feedback device 500 of the steer-by-wire system further includes:

[0126] The second torque determination module is used to obtain the rack rotation speed and calculate the rack friction force based on the rack rotation speed, and determine the second feedback torque based on the rack friction force and a preset second ratio.

[0127] The force feedback module 503 is used to provide force feedback to the steering wheel based on the first feedback torque and the second feedback torque.

[0128] Optionally, the second torque determination module is used to calculate the rack friction force using the following formula:

[0129]

[0130]

[0131]

[0132] Where V is the rotational speed of the rack, and Z is the average deflection of the rack. Let be the first derivative of Z, σ0 be the total stiffness of the rack, σ1 be the damping coefficient of the rack, σ2 be the viscous friction coefficient of the rack, and F be the first derivative of Z. C F is the kinetic friction force of the rack. S V is the static friction force of the rack. S Let G(V) be a preset sliding speed, and F be a preset function of the rack rotation speed. L (V,Z) represents the frictional force of the rack.

[0133] Optionally, the force feedback device 500 of the steer-by-wire system also includes a filtering module and a third torque determination module.

[0134] In some implementations, the filtering module is used to acquire the rack force and filter the rack force to obtain a high-frequency rack force;

[0135] The third torque determination module is used to determine a corresponding third ratio value based on the road feel intensity level set by the user, wherein the third ratio value is proportional to the road feel intensity level, and is also used to determine a third feedback torque based on the high-frequency rack force and the third ratio value.

[0136] The force feedback module 503 is used to provide force feedback to the steering wheel based on the first feedback torque and the third feedback torque.

[0137] In some other implementations, the filtering module is used to acquire the rack force and filter the rack force to obtain high-frequency rack force and low-frequency rack force;

[0138] The third torque determination module is used to determine a corresponding third ratio based on the road feel intensity level set by the user, wherein the third ratio is proportional to the road feel intensity level; it is also used to determine a target gain based on the low-frequency rack force and the vehicle speed, wherein the target gain is proportional to the low-frequency rack force and the vehicle speed, respectively; and it is also used to determine a third feedback torque based on the high-frequency rack force, the third ratio, and the target gain.

[0139] The force feedback module 503 is used to provide force feedback to the steering wheel based on the first feedback torque and the third feedback torque.

[0140] Regarding the force feedback device 500 of the steer-by-wire system in the above embodiments, the specific methods by which each module performs its operation have been described in detail in the embodiments of the force feedback method of the steer-by-wire system, and will not be elaborated here.

[0141] This disclosure also provides a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the steps of the force feedback method for the steer-by-wire system provided in this disclosure.

[0142] This disclosure also provides a chip including a processor and an interface, the processor being configured to read instructions to execute the steps of the force feedback method for the steer-by-wire system provided in this disclosure.

[0143] This disclosure also provides a vehicle, which may be a hybrid vehicle, a non-hybrid vehicle, an electric vehicle, a fuel cell vehicle, or other types of vehicle. The vehicle may be an autonomous vehicle, a semi-autonomous vehicle, or a non-autonomous vehicle.

[0144] The vehicle provided in this disclosure includes a steer-by-wire system, which may include a steering wheel, a steering actuator, and a processor configured to perform the steps of the force feedback method of the steer-by-wire system provided in this disclosure.

[0145] In some embodiments, the steer-by-wire system further includes multiple sensors for collecting data such as steering wheel speed, steering wheel angle, and rack speed.

[0146] In some embodiments, the steering actuator includes a rack.

[0147] In some embodiments, the processor may be an electronic control unit (ECU) of a steer-by-wire system, used to control the steering actuator according to the rotation of the steering wheel and to provide force feedback to the steering wheel.

[0148] The processor can be any conventional processor, such as a commercially available CPU. The processor can also include devices such as Field Programmable Gate Arrays (FPGAs), Systems on Chips (SoCs), Application Specific Integrated Circuits (ASICs), or combinations thereof.

[0149] In another exemplary embodiment, a computer program product is also provided, comprising a computer program executable by a programmable device, the computer program having a code portion for performing the force feedback method of the above-described steer-by-wire system when executed by the programmable device.

[0150] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of this disclosure. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0151] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A force feedback method for a steer-by-wire system, characterized in that, include: Get steering wheel speed, steering wheel angle, and vehicle speed; The steering wheel rotation direction is determined based on the steering wheel rotation speed, and the corresponding first basic force is determined based on the steering wheel rotation direction and the steering wheel angle. A first ratio is determined based on the vehicle speed, and the first ratio is inversely proportional to the vehicle speed; The first feedback torque is determined based on the first basic force and the first ratio. Force feedback is applied to the steering wheel based on the first feedback torque; The method further includes: The rack force is acquired and filtered to obtain the high-frequency rack force and the low-frequency rack force; A third ratio is determined based on the road feel intensity level set by the user, and the third ratio is proportional to the road feel intensity level. The target gain is determined based on the low-frequency rack force and the vehicle speed, wherein the target gain is proportional to the low-frequency rack force and the vehicle speed, respectively. The third feedback torque is determined based on the high-frequency rack force, the third ratio, and the target gain; The step of providing force feedback to the steering wheel based on the first feedback torque includes: Force feedback is provided to the steering wheel based on the first feedback torque and the third feedback torque.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the rack rotation speed and calculate the rack friction force based on the rack rotation speed; The second feedback torque is determined based on the rack friction force and the preset second ratio. The step of providing force feedback to the steering wheel based on the first feedback torque includes: Force feedback is provided to the steering wheel based on the first feedback torque and the second feedback torque.

3. The method according to claim 2, characterized in that, The calculation of rack friction based on rack rotation speed includes: The rack friction force is calculated using the following formula: in, V The rotational speed of the rack, Z The average deflection of the rack. for Z The first derivative, σ 0 represents the total stiffness of the rack. σ 1 represents the damping coefficient of the rack. σ 2 is the coefficient of viscous friction of the rack. F C The dynamic friction force of the rack is... F S The static friction force of the rack is... V S The preset sliding speed, For a preset function of the rack rotation speed, The frictional force of the rack is denoted as .

4. A force feedback device for a steer-by-wire system, characterized in that, include: The data acquisition module is used to acquire steering wheel speed, steering wheel angle, and vehicle speed; The first torque determination module is used to determine the steering wheel rotation direction based on the steering wheel rotation speed, and to determine the corresponding first basic force based on the steering wheel rotation direction and the steering wheel angle. It is also used to determine the corresponding first ratio based on the vehicle speed, the first ratio being inversely proportional to the vehicle speed. Furthermore, it is used to determine the first feedback torque based on the first basic force and the first ratio. The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque; A filtering module is used to acquire rack force and filter rack force to obtain high-frequency rack force and low-frequency rack force; The third torque determination module is used to determine a corresponding third ratio based on the road feel intensity level set by the user. The third ratio is proportional to the road feel intensity level. It is also used to determine a target gain based on the low-frequency rack force and the vehicle speed. The target gain is proportional to the low-frequency rack force and the vehicle speed, respectively. It is also used to determine a third feedback torque based on the high-frequency rack force, the third ratio, and the target gain. The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque and the third feedback torque.

5. The apparatus according to claim 4, characterized in that, The device further includes: The second torque determination module is used to obtain the rack rotation speed and calculate the rack friction force based on the rack rotation speed, and determine the second feedback torque based on the rack friction force and a preset second ratio. The force feedback module is used to provide force feedback to the steering wheel based on the first feedback torque and the second feedback torque.

6. A vehicle, characterized in that, include: A steer-by-wire system, comprising a steering wheel, a steering actuator, and a processor, the processor being configured to perform a force feedback method of the steer-by-wire system according to any one of claims 1-3.

7. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the program instructions are executed by the processor, they implement the force feedback method of the steer-by-wire system as described in any one of claims 1-3.

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