Rear wheel alignment device, steering system, vehicle, control method and device

Abstract

A rear wheel alignment device (8) belongs to the technical field of vehicles, including a shell (81), a first sliding body (82), a second sliding body (83) and a driving component (84), the first sliding body (82) and the second sliding body (83) are linked with the tie rod (3). When the tie rod (3) needs to be aligned, the driving component (84) is switched to the first state with larger driving force, and the first sliding body (82) or the second sliding body (83) is driven to slide, and the first sliding body (82) or the second sliding body (83) drives the tie rod (3) to align. When the rear wheel steering system is normal, the first sliding body (82) and the second sliding body (83) slide with the tie rod (3), then the driving component (84) is switched to the second state with smaller driving force, the resistance generated by the first sliding body (82) and the second sliding body (83) is reduced, and the driving safety of the vehicle is improved. Also relates to a rear wheel steering system, a vehicle, a rear wheel alignment control method and a control device.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, and in particular to a rear wheel return device, steering system, vehicle, control method and apparatus. Background Technology

[0002] Rear-wheel steering, as an active chassis control technology, can control the rear wheels to produce a certain tire deflection angle according to the vehicle's dynamic state, thereby improving the vehicle's handling, safety, and comfort.

[0003] Generally speaking, at low speeds, the rear wheels exhibit a deflection angle opposite to that of the front wheels, significantly reducing the vehicle's turning radius, enhancing yaw response, and making the vehicle more agile and maneuverable. At high speeds, the rear wheels exhibit a deflection angle in the same direction as the front wheels, allowing for rapid establishment of lateral force on the rear axle, improving lateral acceleration response, and significantly enhancing vehicle handling stability.

[0004] However, if the rear-wheel steering system malfunctions, it may cause the rear wheels to move uncontrollably, seriously affecting the vehicle's driving safety. Summary of the Invention

[0005] This disclosure provides a rear wheel return-to-center device, a steering system, a vehicle, a control method, and an apparatus. In the rear wheel return-to-center device, a first sliding body and a second sliding body are linked to a tie rod. When the rear wheel steering system fails to properly drive the rear wheels, the driving component in the rear wheel return-to-center device drives the first or second sliding body to slide. The first or second sliding body then acts as the active component, driving the tie rod back to center, thus switching the vehicle from four-wheel steering to front-wheel steering, improving driving safety. The technical solutions for the rear wheel return-to-center device, steering system, vehicle, control method, and apparatus are described below:

[0006] In a first aspect, this disclosure provides a rear wheel return-to-center device, comprising a housing, a first sliding body, a second sliding body, and a drive component. The housing is for fixing to a vehicle. The first and second sliding bodies are located inside the housing and are linked to the tie rod of the rear wheel steering system. The drive component has a first state and a second state, wherein the driving force of the drive component in the first state is greater than the driving force in the second state. In the first state, the drive component drives the first or second sliding body to slide, and the first or second sliding body drives the tie rod to return to center.

[0007] The sliding body (the first sliding body or the second sliding body) is in linkage with the tie rod, and can also be understood as being in transmission connection with the tie rod. The linkage between the sliding body and the tie rod means that the position of the sliding body is associated with the position of the tie rod, and the change in the position of the tie rod will cause the change in the position of the sliding body, and similarly, the change in the position of the sliding body will also cause the change in the position of the tie rod. Therefore, by controlling the driving component to apply a driving force large enough to the sliding body, the sliding body can drive the tie rod to return to the normal position as a driving part. In addition, in the normal rear wheel steering process of the vehicle, the sliding body moves with the tie rod, and will generate a certain resistance to the tie rod or the rear wheel steering driving device.

[0008] The technical solution provided by the present disclosure is that the driving component has the first state and the second state with different driving forces, so that when the rear wheel return device needs to drive the tie rod to return to the normal position, the driving component can be switched to the first state with a larger driving force, so that the driving component outputs sufficient driving force to drive the first sliding body or the second sliding body to slide, and the first sliding body or the second sliding body drives the tie rod to return to the normal position as a driving part.

[0009] In a possible implementation, in the second state, the first sliding body or the second sliding body slides under the driving of the rear wheel steering driving device of the rear wheel steering system or the tie rod. Since the sliding body provides resistance in the normal rear wheel steering process of the vehicle, by switching the driving component to the second state with a smaller driving force, the resistance to the tie rod or the rear wheel steering driving device is reduced, and the energy consumption of the rear wheel steering driving device is reduced.

[0010] In a possible implementation, when the first sliding body and the second sliding body are located at the first position and the second position respectively, the tie rod is in the return state. Therefore, by driving the first sliding body and the second sliding body to slide to the first position and the second position respectively, the tie rod can be driven to return to the normal position. In a possible implementation, the driving component is configured to apply a driving force to the first sliding body towards the first position, and to apply a driving force to the second sliding body towards the second position, and the driving force output by the driving component in the first state is greater than the driving force output by the driving component in the second state. In the first state, under the action of the driving force of the driving component, the first sliding body slides towards the first position or remains at the first position, and the second sliding body slides towards the second position or remains at the second position.

[0011] In a possible implementation, when the first sliding body is located at the first position and the second sliding body is located between the first position and the second position, the tie rod is in the first offset state. Then, when the tie rod needs to be switched from the first offset state to the return state, the driving component is switched to the first state, and the driving component drives the second sliding body to slide to the second position. At the same time, the driving component can also drive the first sliding body to remain at the first position.

[0012] In a possible implementation, when the first sliding body is between the first position and the second position and the second sliding body is at the second position, the tie rod is in the second offset state. Then, when the tie rod needs to be switched from the second offset state to the normal state, the driving component is switched to the first state, and the driving component drives the first sliding body to slide to the first position. Meanwhile, the driving component can also drive the second sliding body to remain at the second position.

[0013] In a possible implementation, one of the first offset state and the second offset state is a left offset state, and the other is a right offset state.

[0014] In a possible implementation, the first sliding body and the second sliding body are sleeved around the tie rod and located between the two first flanges of the tie rod, and when the first sliding body and the second sliding body are at the first position and the second position respectively, the first sliding body and the second sliding body are in contact with the two first flanges respectively.

[0015] In the normal rear wheel steering process, the tie rod moves under the action of the rear wheel steering driving device, and in the movement process of the tie rod, a first flange on the tie rod drives the first sliding body or the second sliding body to slide.

[0016] In the process of driving the tie rod to return to the normal state by the rear wheel return device, the first sliding body or the second sliding body, as a driving part, pushes the tie rod to return to the normal state through the corresponding first flange under the driving force of the driving component.

[0017] In a possible implementation, the rear wheel return device is arranged on the transmission shaft between the rear wheel steering motor and the speed reduction unit. In this way, since the rear wheel return device is located at the input end of the speed reduction unit, the rear wheel return device can drive the tie rod to return to the normal state with smaller driving force. Thus, the driving force required by the rear wheel return device in the first state is reduced, the energy consumption of the rear wheel return device is reduced, the volume of the rear wheel return device is reduced, and the rear wheel return device is more easily arranged.

[0018] In a possible implementation, the rear wheel return device further includes a first lead screw and a first nut, the first lead screw is fixed on the transmission shaft between the rear wheel steering motor and the speed reduction unit of the rear wheel steering system, and the first nut is sleeved around the first lead screw, so that the first nut and the first lead screw form a lead screw nut mechanism or a ball screw mechanism. The first nut has two second flanges, the first sliding body and the second sliding body are located between the two second flanges, and when the first sliding body and the second sliding body are at the first position and the second position respectively, the first sliding body and the second sliding body are in contact with the two second flanges respectively.

[0019] In the normal rear wheel steering process, the rear wheel steering motor drives the transmission shaft to rotate, the transmission shaft drives the first screw rod to rotate, and the first screw rod drives the first nut to slide. In the sliding process of the first nut, the first nut drives the first sliding body or the second sliding body to slide through the second flange. At the same time, the transmission shaft also drives the tie rod to deviate through the reduction unit to realize the steering of the rear wheel.

[0020] In the process of driving the tie rod to return to the normal position by the rear wheel returning device, the first sliding body or the second sliding body is driven to slide the first nut through the corresponding second flange under the driving force of the driving part. In the sliding process of the first nut, the first nut drives the first screw rod to rotate, the first screw rod drives the transmission shaft to rotate, and the transmission shaft drives the tie rod to return to the normal position through the reduction unit.

[0021] In a possible implementation, the transmission shaft includes a first shaft segment, a second shaft segment, and a clutch, the first shaft segment and the second shaft segment are connected through the clutch, the second shaft segment is connected with the reduction unit, and the first screw rod is fixed on the second shaft segment.

[0022] In a possible implementation, the driving force output by the driving part in the second state is 0.

[0023] In a possible implementation, the driving force output by the driving part in the second state is greater than 0, so that in the second state, under the action of the driving force output by the driving part, the first sliding body and the second sliding body are either stable in the first position or the second position, or are in close contact with the first flange or the second flange, and the first sliding body and the second sliding body will not slide uncontrollably.

[0024] In a possible implementation, the driving part includes a first electromagnetic coil and a second electromagnetic coil, the first electromagnetic coil and the second electromagnetic coil are fixed inside the shell, and the first sliding body and the second sliding body are located between the first electromagnetic coil and the second electromagnetic coil.

[0025] In the first state, the first electromagnetic coil and the second electromagnetic coil are energized. The first electromagnetic coil attracts the first sliding body to slide to or keep in the first position, and the second electromagnetic coil attracts the second sliding body to slide to or keep in the second position. In the sliding process of the first sliding body or the second sliding body, the first sliding body or the second sliding body drives the tie rod to return to the normal position.

[0026] In a possible implementation, in the second state, the first electromagnetic coil and the second electromagnetic coil are energized, and the current input is less than the current input in the first state. In this way, the driving force of the driving part in the second state is less than that in the first state.

[0027] In a possible implementation, in the second state, the first electromagnetic coil and the second electromagnetic coil are powered off. In this way, the energy consumption of the driving component can be reduced, and the service life of the driving component can be prolonged. Moreover, the driving force of the driving component in the second state is less than that in the first state.

[0028] In a possible implementation, the driving component includes an electromagnetic valve, which is in communication with a high-pressure gas passage, a low-pressure gas passage and a chamber between the first sliding body and the second sliding body on the vehicle.

[0029] In the first state, the electromagnetic valve communicates the chamber with the high-pressure gas passage, and the high-pressure gas enters the chamber and pushes the first sliding body to slide to or stay at the first position and pushes the second sliding body to slide to or stay at the second position. During the sliding of the first sliding body or the second sliding body, the first sliding body or the second sliding body drives the tie rod to straighten.

[0030] In the second state, the electromagnetic valve communicates the chamber with the low-pressure gas passage, and the high-pressure gas is discharged through the low-pressure gas passage. The driving force acting on the first sliding body and the second sliding body is reduced.

[0031] In a possible implementation, the driving component further includes an elastic member, two ends of the elastic member are respectively in abutment with the first sliding body and the second sliding body. The elastic member can be used to apply a driving force to the first sliding body towards the first position and to the second sliding body towards the second position in the second state. Moreover, since the elastic member does not need to be connected to a power supply, the energy consumption of the driving component in the second state is 0 or very low.

[0032] In a possible implementation, the rear wheel straightening device further includes a brake, which is configured to lock the position of the tie rod after the tie rod is straightened.

[0033] In this way, the position of the tie rod can be locked in the straightened state by the brake, and then the driving component can be switched back to the second state without having to remain in the first state with a larger driving force, thereby reducing the energy consumption of the driving component.

[0034] In a possible implementation, the brake is arranged on a transmission shaft between a rear wheel steering motor and a speed reduction unit of the rear wheel steering system.

[0035] In a possible implementation, the transmission shaft includes a first shaft segment, a second shaft segment and a clutch, the first shaft segment and the second shaft segment are connected through the clutch, the second shaft segment is connected with the speed reduction unit, and the brake is arranged on the second shaft segment.

[0036] In this way, after the clutch is disconnected, the brake can still lock the position of the tie rod.

[0037] In a possible implementation, the driving component further has a third state, the driving force of the driving component in the third state is greater than the driving force in the second state and less than the driving force in the first state. In the third state, the driving component drives the first sliding body and the second sliding body to be kept at the first position and the second position respectively.

[0038] In this way, after the tie rod is returned, the driving component can be controlled to switch from the first state to the third state to reduce the energy consumption of the driving component.

[0039] In a possible implementation, after the tie rod is returned, the driving component is kept in the first state.

[0040] In a second aspect, the present disclosure provides a rear wheel steering system, the rear wheel steering system comprising a rear wheel steering control unit, a rear wheel steering driving device, a tie rod and the rear wheel returning device of any one of the first aspect. The rear wheel steering driving device is in driving connection with the tie rod, and the rear wheel steering control unit is configured to: determine that the tie rod needs to be returned by the rear wheel returning device, and control the driving component to switch to the first state.

[0041] The rear wheel steering control unit comprises one or both of a vehicle control unit and a rear wheel steering electronic control unit.

[0042] The rear wheel steering driving device comprises a rear wheel steering motor, a transmission shaft, a speed reduction unit, a conversion unit and a stroke sensor. The rear wheel steering motor can be a brushless motor. The rear wheel steering motor is connected with the speed reduction unit through the transmission shaft, the speed reduction unit is connected with the conversion unit, the conversion unit is connected with the tie rod, and the conversion unit is used for converting rotation into linear motion of the tie rod, so that the rear wheel steering motor drives the linear motion of the tie rod. The stroke sensor is arranged on the tie rod and is used for detecting the position of the tie rod.

[0043] The technical solution provided by the present disclosure is that the rear wheel returning device of the first aspect is applied to the rear wheel steering system, so that when it is determined that the tie rod needs to be returned by the rear wheel returning device, the driving component can be controlled to switch to the first state. In the first state, the driving component drives the first sliding body or the second sliding body to slide, and the first sliding body or the second sliding body drives the tie rod to return as a driving member.

[0044] In a possible implementation, the rear wheel steering system further comprises a left connecting assembly and a right connecting assembly, and two ends of the tie rod are connected with the left connecting assembly and the right connecting assembly respectively.

[0045] The left connecting assembly and the right connecting assembly are respectively configured to connect with the left rear wheel and the right rear wheel. The left connecting assembly comprises a left steering drag link and a left knuckle arm, and the right connecting assembly comprises a right steering drag link and a right knuckle arm. When the cross drag link moves, the cross drag link drives the left rear wheel and the right rear wheel to steer through the left connecting assembly and the right connecting assembly respectively.

[0046] In a possible implementation, the rear wheel steering system further comprises a left rear wheel and a right rear wheel.

[0047] In a possible implementation, the rear wheel steering control unit is further configured to, when determining that the rear wheel alignment device is required to align the cross drag link, control the driving component to switch to or remain in the second state. In the second state, the driving force output by the driving component is smaller, and thus the resistance caused by the first sliding body and the second sliding body can be reduced.

[0048] In a possible implementation, the rear wheel steering control unit is configured to, when determining that the rear wheel steering system is in the first fault state, determine that the rear wheel alignment device is required to align the cross drag link.

[0049] In a possible implementation, the first fault state refers to a state in which the rear wheel steering driving device is unable to drive the cross drag link to align.

[0050] In a possible implementation, the first fault state comprises one or more of the following states: power failure of the rear wheel steering driving device, power failure of a rear wheel steering motor in the rear wheel steering driving device, and sensor failure in the rear wheel steering driving device, wherein the sensor is configured to determine the position of the cross drag link.

[0051] In a possible implementation, when the rear wheel alignment device comprises a brake, after the driving component is controlled to switch to the first state, the rear wheel steering control unit is further configured to, when determining that the cross drag link is in the alignment state, control the brake to lock the position of the cross drag link. In this way, the cross drag link can be maintained in the alignment state.

[0052] In a possible implementation, after the position of the cross drag link is locked by the brake, the rear wheel steering control unit controls the driving component to switch to the second state to reduce the energy consumption of the driving component.

[0053] In a possible implementation, if the rear wheel steering driving device is required to drive the cross drag link to align, after the position of the cross drag link is locked by the brake, the rear wheel steering control unit controls a rear wheel steering motor in the rear wheel steering driving device to be turned off to reduce the energy consumption.

[0054] In a possible implementation, when the driving component has the third state, after the driving component is controlled to switch to the first state, the rear wheel steering control unit is further configured to, when it is determined that the track rod is in the return state, control the driving component to switch to the third state, so as to reduce the energy consumption of the driving component.

[0055] In a possible implementation, the rear wheel steering control unit is further configured to, when it is determined that the rear wheel steering system is in the second fault state, control the rear wheel steering driving device to drive the track rod to return.

[0056] The second fault state refers to a state in which the rear wheel steering system fails but still retains the ability to drive the track rod to return.

[0057] In a possible implementation, the second fault state includes one or more of the following states: the rear wheel steering motor of the rear wheel steering driving device is over-temperature or overloaded, and the rear wheel steering control unit cannot receive the rear wheel angle signal.

[0058] In a possible implementation, the rear wheel steering driving device includes a rear wheel steering motor, a transmission shaft and a reduction unit connected in sequence, and the reduction unit is in transmission connection with the track rod. The transmission shaft includes a first shaft section, a second shaft section and a clutch, and the first shaft section and the second shaft section are connected through the clutch. Before the driving component is controlled to switch to the first state, the rear wheel steering control unit is further configured to control the clutch to be separated. In this way, the mechanical connection between the track rod and the rear wheel steering motor can be disconnected, and the influence of the rear wheel steering motor on the return of the track rod can be avoided.

[0059] In a third aspect, the present disclosure provides a vehicle including the rear wheel return device of any one of the first aspect or the rear wheel steering system of any one of the second aspect.

[0060] In a fourth aspect, the present disclosure provides a control method of a rear wheel return, which is applied to a rear wheel steering control unit of a rear wheel steering system of any one of the second aspect, and includes: if it is determined that the rear wheel return device needs to drive the track rod to return, controlling a driving component to switch to a first state. After the driving component switches to the first state, the driving component drives a first sliding body or a second sliding body to slide, and the second sliding body or the second sliding body drives the track rod to return.

[0061] In a possible implementation, if it is determined that the rear wheel return device does not need to drive the track rod to return, the driving component is controlled to switch to or remain in a second state. In the second state, the driving force output by the driving component is smaller, and therefore, the resistance brought by the first sliding body and the second sliding body can be reduced.

[0062] In a possible implementation, when it is determined that the rear wheel steering system is in the first failure state, it is determined that the rear wheel straightening device needs to drive the track rod to straighten.

[0063] The first failure state refers to a state in which the rear wheel steering driving device cannot drive the track rod to straighten.

[0064] In a possible implementation, the first failure state includes one or more of the following states: power failure of the rear wheel steering driving device, rear wheel steering motor power failure of the rear wheel steering driving device, and sensor failure of the rear wheel steering driving device, wherein the sensor is used to determine the position of the track rod, and the sensor can be a stroke sensor.

[0065] In a possible implementation, when the rear wheel straightening device further includes a brake, after the driving component is controlled to switch to the first state, if it is determined that the track rod is in the straightening state, the brake is controlled to lock the position of the track rod.

[0066] In a possible implementation, after the brake is controlled to lock the position of the track rod, the driving component is controlled to switch to the second state to reduce the energy consumption of the driving component.

[0067] In a possible implementation, if the rear wheel steering driving device drives the track rod to straighten, after the brake is controlled to lock the position of the track rod, the rear wheel steering motor in the rear wheel steering driving device is controlled to be turned off to reduce the energy consumption.

[0068] In a possible implementation, when the driving component has a third state, after the driving component is controlled to switch to the first state, if it is determined that the track rod is in the straightening state, the driving component is controlled to switch to the third state. Since the driving force of the driving component in the third state is smaller than that in the first state, the driving component switching to the third state can reduce the energy consumption of the driving component.

[0069] In a possible implementation, when the rear wheel steering driving device includes a clutch, before the driving component is controlled to switch to the first state, the clutch is controlled to be separated, so that the mechanical connection between the track rod and the rear wheel steering motor is disconnected, and the rear wheel steering motor is prevented from affecting the straightening of the track rod.

[0070] In a possible implementation, the control method further includes: determining that the rear wheel steering system is in a second failure state, and controlling the rear wheel steering driving device to drive the track rod to straighten.

[0071] The second failure state refers to a state in which the rear wheel steering system fails, but still retains the ability to drive the track rod to straighten.

[0072] In a possible implementation, the second fault state comprises one or more of the following states: over-temperature or over-load of the rear wheel steering motor in the rear wheel steering driving device, the rear wheel steering control unit failing to receive the rear wheel steering angle signal.

[0073] In a fifth aspect, the present disclosure provides a rear wheel straightening control device, the control device being located in the rear wheel steering control unit of the rear wheel steering system according to any one of the second aspect, the control device comprising: a determination module configured to determine that the rear wheel straightening device needs to drive the track rod to straighten; and a control module configured to control the driving component to switch to the first state.

[0074] In a possible implementation, the determination module is configured to determine that the rear wheel straightening device needs to drive the track rod to straighten when it is determined that the rear wheel steering system is in the first fault state.

[0075] In a possible implementation, the first fault state comprises one or more of the following states: power failure of the rear wheel steering driving device, power failure of the rear wheel steering motor of the rear wheel steering driving device, sensor failure of the rear wheel steering driving device, and the sensor being configured to determine the position of the track rod.

[0076] In a possible implementation, when the rear wheel straightening device further comprises a brake, after the control module controls the driving component to switch to the first state, the determination module is further configured to determine that the track rod is in the straightening state, and the control module is further configured to control the brake to lock the position of the track rod and control the driving component to switch to the second state.

[0077] In a possible implementation, when the driving component has a third state, after the control module controls the driving component to switch to the first state, the determination module is further configured to determine that the track rod is in the straightening state, and the control module is further configured to control the driving component to switch to the third state.

[0078] In a possible implementation, when the rear wheel steering driving device comprises a clutch, before the control module controls the driving component to switch to the first state, the control module is further configured to control the clutch to be separated.

[0079] In a possible implementation, the determination module is further configured to determine that the rear wheel steering system is in a second fault state, and the control module is further configured to control the rear wheel steering driving device to drive the track rod to straighten.

[0080] In a possible implementation, the second fault state comprises one or more of the following states: over-temperature or over-load of the rear wheel steering motor in the rear wheel steering driving device, and the rear wheel steering control unit failing to receive the rear wheel steering angle signal.

[0081] In a sixth aspect, this disclosure provides a computer-readable storage medium storing at least one instruction, which is loaded and executed by a controller to implement the post-cycle positive control method as described in any of the fourth aspects.

[0082] In a seventh aspect, this disclosure provides a computer program product comprising at least one instruction that is executed by a controller to cause the controller to implement the post-cycle positive control method as described in any of the fourth aspects.

[0083] Eighthly, this disclosure provides a chip including a controller for retrieving and executing instructions stored in a memory, causing an electronic control unit on which the chip is mounted to perform the post-cycle positive control method described in any of the fourth aspects above.

[0084] In one possible implementation, the electronic control unit is the rear wheel steering control unit in the second aspect.

[0085] Ninthly, this disclosure provides another chip, which includes: an input interface, an output interface, a controller, and a memory. The input interface, the output interface, the controller, and the memory are connected through an internal connection path. The controller is used to execute code in the memory. When the code is executed, the controller is used to execute the post-cycle positive control method described in any of the fourth aspects above.

[0086] In a tenth aspect, this disclosure provides an electronic control unit, which includes a controller coupled to a memory. The memory stores at least one instruction, which is loaded and executed by the controller to implement the post-cycle positive control method as described in any of the fourth aspects.

[0087] In one possible implementation, the electronic control unit is the rear wheel steering control unit in the second aspect. Attached Figure Description

[0088] Figure 1 This is a schematic diagram of a steering system provided in an embodiment of this disclosure;

[0089] Figure 2 This is a schematic diagram of a rear-wheel steering system provided in an embodiment of this disclosure;

[0090] Figure 3 This is a schematic diagram illustrating the working process of a rear circulation positive device provided in an embodiment of this disclosure;

[0091] Figure 4 This is a schematic diagram of a rear-wheel steering system provided in an embodiment of this disclosure;

[0092] Figure 5is a schematic diagram of a working process of a rear wheel alignment device provided by an embodiment of the present disclosure;

[0093] Figure 6 is a schematic diagram of a rear wheel steering system provided by an embodiment of the present disclosure;

[0094] Figure 7 is a schematic diagram of a rear wheel steering system provided by an embodiment of the present disclosure;

[0095] Figure 8 is a schematic diagram of a working process of a rear wheel alignment device provided by an embodiment of the present disclosure;

[0096] Figure 9 is a schematic diagram of an air supply system of an air suspension on a vehicle provided by an embodiment of the present disclosure;

[0097] Figure 10 is a schematic diagram of an air supply system of an air suspension on a vehicle provided by an embodiment of the present disclosure;

[0098] Figure 11 is a flowchart of a method for determining a fault handling mode provided by an embodiment of the present disclosure;

[0099] Figure 12 is a flowchart of a fault handling mode 1 provided by an embodiment of the present disclosure;

[0100] Figure 13 is a flowchart of a fault handling mode 1 provided by an embodiment of the present disclosure;

[0101] Figure 14 is a flowchart of a fault handling mode 2 provided by an embodiment of the present disclosure;

[0102] Figure 15 is a flowchart of a fault handling mode 2 provided by an embodiment of the present disclosure;

[0103] Figure 16 is a flowchart of a fault handling mode 2 provided by an embodiment of the present disclosure;

[0104] Figure 17 is a flowchart of a fault handling mode 2 provided by an embodiment of the present disclosure;

[0105] Figure 18 is a flowchart of a control method for rear wheel alignment provided by an embodiment of the present disclosure;

[0106] Figure 19 is a structural schematic diagram of a control device for rear wheel alignment provided by an embodiment of the present disclosure;

[0107] Figure 20 is a schematic diagram of an electronic control unit provided by an embodiment of the present disclosure.

[0108] Legend

[0109] 100, vehicle control unit, 200, steering wheel, 300, steering wheel angle sensor, 400, vehicle speed sensor, 500, yaw rate sensor, 600, lateral acceleration sensor, 700, rear wheel steering ECU;

[0110] 1, rear wheel steering control unit;

[0111] 2, rear wheel steering driving device, 21, rear wheel steering motor, 22, transmission shaft, 221, first shaft section, 222, second shaft section, 223, clutch, 23, speed reduction unit, 231, driving wheel, 232, driven wheel, 233, transmission belt, 24, conversion unit, 241, second nut, 242, second lead screw, 25, stroke sensor;

[0112] 3, tie rod, 31, first flange;

[0113] 4, left connecting assembly, 41, left steering drag link, 42, left steering knuckle arm, 5, right connecting assembly, 51, right steering drag link, 52, right steering knuckle arm, 6, left rear wheel, 7, right rear wheel;

[0114] 8, rear wheel alignment device, 80, chamber, 81, housing, 82, first sliding body, 83, second sliding body, 84, driving component, 841, first electromagnetic coil, 842, second electromagnetic coil, 843, electromagnetic valve, 844, high-pressure gas circuit, 845, low-pressure gas circuit, 846, elastic member, 85, first lead screw, 86, first nut, 861, second flange, 87, brake, 88, sealing ring;

[0115] 9, air supply system, 91, distribution valve, 92, air supply system control unit, 93, high-pressure gas tank, 94, air compressor. DETAILED DESCRIPTION

[0116] The steering system of a vehicle is mainly used to control the yaw and lateral motion of the vehicle. For a front wheel steering vehicle, the driver turns the steering wheel to generate tire cornering angle of the front wheels, and then the vehicle travels along the desired trajectory.

[0117] As an active chassis control technology, the rear wheel steering system can control the rear wheels to produce a certain tire deflection angle according to the vehicle dynamics state, which can greatly improve the handling stability, safety and comfort of the vehicle. Generally speaking, in the low-speed driving condition, the rear wheels are controlled to produce a deflection angle opposite to that of the front wheels, so that the turning radius of the vehicle is significantly reduced, the yaw response is enhanced, and the vehicle becomes more sensitive and maneuverable. In the high-speed driving condition, the rear wheels are controlled to produce a deflection angle in the same direction as that of the front wheels, so that the lateral force of the rear axle can be quickly established, the lateral acceleration response is improved, and the handling stability of the vehicle is significantly improved. The active rear wheel steering technology can significantly change the steering characteristics of the vehicle, which has an important influence on vehicle safety.

[0118] In order to better understand the technical solutions provided by the embodiments of the present disclosure, the steering system of the vehicle will be described first as follows:

[0119] As shown in Figure 1 , the steering system of the vehicle includes a vehicle control unit 100, a steering wheel 200, a steering wheel angle sensor 300, a vehicle speed sensor 400, a yaw rate sensor 500, a lateral acceleration sensor 600, a rear wheel steering electronic control unit (ECU) 700 and a rear wheel steering (RWS) system. The rear wheel steering system includes a rear wheel steering driving device 2, a tie rod 3, a left connecting assembly 4, a right connecting assembly 5, a left rear wheel 6 and a right rear wheel 7. In addition, at least one of the vehicle control unit 100 and the rear wheel steering ECU 700 can be considered as a rear wheel steering control unit 1 and belong to the rear wheel steering system.

[0120] The rear wheel steering driving device 2 includes a rear wheel steering motor 21, a transmission shaft 22, a speed reduction unit 23, a conversion unit 24 and a stroke sensor 25.

[0121] The rear wheel steering motor 21 can be a brushless motor. The rear wheel steering motor 21 is connected with the speed reduction unit 23 through the transmission shaft 22, the speed reduction unit 23 is connected with the conversion unit 24, the conversion unit 24 is connected with the tie rod 3, and the conversion unit 24 is used to convert the rotation into the linear motion of the tie rod 3, so that the rear wheel steering motor 21 drives the linear motion of the tie rod 3. The stroke sensor 25 is arranged on the tie rod 3 and is used to detect the position of the tie rod 3, for example, to detect whether the tie rod 3 is in a normal state or a deflection state, and the deflection stroke of the tie rod 3.

[0122] In some examples, as Figure 1As shown, the deceleration unit 23 includes a driving wheel 231 fixed on the transmission shaft 22, a driven wheel 232, and a transmission belt 233 connecting the driving wheel 231 and the driven wheel 232. The diameter of the driving wheel 231 is smaller than that of the driven wheel 232, so that the rotation speed of the driven wheel 232 is smaller than that of the driving wheel 231, achieving deceleration. In addition to the belt deceleration mechanism shown in the figure, in other examples, the deceleration unit 23 can also be selected from a planetary gear deceleration mechanism, etc.

[0123] In some examples, as shown, Figure 1 As shown, the conversion unit 24 includes a second nut 241 and a second lead screw 242. The second lead screw 242 is fixed on the cross rod 3, and the second nut 241 is sleeved on the second lead screw 242. The second nut 241 is arranged on the driven wheel 232 (or understood as the second nut 241 and the driven wheel 232 being the same component). During the rotation of the driven wheel 232 (second nut 241), the second lead screw 242 can be driven to move linearly, and in turn, the cross rod 3 is driven to move linearly. In addition to the lead screw nut mechanism shown in the figure, in other examples, the conversion unit 24 can also be selected from a gear and rack mechanism.

[0124] The two ends of the cross rod 3 are connected with the left rear wheel 6 and the right rear wheel 7 through the left connecting assembly 4 and the right connecting assembly 5, respectively. The left connecting assembly 4 includes a left steering pull rod 41 and a left knuckle arm 42, and the right connecting assembly 5 includes a right steering pull rod 51 and a right knuckle arm 52. When the cross rod 3 moves, the cross rod 3 drives the left rear wheel 6 and the right rear wheel 7 to steer through the left connecting assembly 4 and the right connecting assembly 5, respectively.

[0125] Next, the control logic of the rear wheel steering system is described:

[0126] During normal steering driving, the vehicle control unit 100 receives the steering wheel angle signal from the steering wheel angle sensor 300, the vehicle speed signal from the vehicle speed sensor 400, the yaw angular velocity signal from the yaw angular velocity sensor 500, and the lateral acceleration signal from the lateral acceleration sensor 600, and outputs the rear wheel angle signal to the rear wheel steering ECU 700 after calculation.

[0127] The rear wheel steering ECU 700 controls the actuation of the rear wheel steering motor 21 according to the rear wheel angle signal and the position of the cross rod 3 detected by the stroke sensor 25. The rotation of the rear wheel steering motor 21 is converted into linear motion of the cross rod 3 through the deceleration unit 23 and the conversion unit 24, and the cross rod 3 drives the left rear wheel 6 and the right rear wheel 7 to steer.

[0128] When the rear wheel steering system fails, for example, the rear wheel steering motor 21 rotates uncontrollably, which can cause the rear wheel to move uncontrollably, seriously affecting driving safety. In order to avoid the rear wheel from moving uncontrollably, a mechanical self-locking device is used in the related art to lock the last steering angle position when a failure occurs, to prevent the rear wheel from moving uncontrollably. However, if the last steering angle position where the failure occurs is not the central position, the rear wheel will always have a fixed steering angle, the steering characteristics of the vehicle will change significantly, and the vehicle will still have unexpected steering behavior, which is prone to accidents.

[0129] In view of the above technical problems, the embodiments of the present disclosure provide a rear wheel straightening device 8, which can drive the tie rod 3 to straighten when the rear wheel steering system cannot straighten normally, so that the vehicle is converted from four-wheel steering to front-wheel steering, improving the safety of vehicle driving. And when the rear wheel steering system is normal, the rear wheel straightening device 8 can reduce the driving force for straightening the tie rod 3, to reduce the resistance encountered when the tie rod 3 or the rear wheel steering driving device 2 moves.

[0130] Next, the rear wheel straightening device 8 provided by the embodiments of the present disclosure will be described exemplarily:

[0131] As shown in Figures 2-8 , the rear wheel straightening device 8 includes a housing 81, a first sliding body 82, a second sliding body 83, and a driving component 84. The housing 81 is used to be fixed to the vehicle, the first sliding body 82 and the second sliding body 83 are located inside the housing 81, and are linked with the tie rod 3 of the rear wheel steering system. The driving component 84 has a first state and a second state, and the driving force of the driving component 84 in the first state is greater than that in the second state. In the first state, the driving component 84 drives the first sliding body 82 or the second sliding body 83 to slide, and the first sliding body 82 or the second sliding body 83 drives the tie rod 3 to straighten.

[0132] Among them, the sliding body (the first sliding body 82, the second sliding body 83) is linked with the tie rod 3, which can also be understood as that the sliding body is in transmission connection with the tie rod 3. The sliding body is linked with the tie rod 3, which means that the position of the sliding body is associated with the position of the tie rod 3, and the change of the position of the tie rod 3 will cause the change of the position of the sliding body, and similarly, the change of the position of the sliding body will also cause the change of the position of the tie rod 3. Therefore, by controlling the driving component 84 to apply a large enough driving force to the sliding body, the sliding body can be driven to straighten the tie rod 3 as the driving part.

[0133] In addition, during normal rear wheel steering of the vehicle, the sliding body follows the movement of the tie rod 3 and generates resistance to the tie rod 3 or the rear wheel steering driving device 2. For example, if the driving component 84 always applies a driving force to the sliding body to return the tie rod 3 to the normal state, the rear wheel steering driving device 2 needs to overcome the driving force during driving of the tie rod 3.

[0134] The technical solution provided by the embodiments of the present disclosure sets the driving component 84 to have a first state and a second state with different driving forces, so that when the rear wheel return device 8 needs to drive the tie rod 3 to return to the normal state, the driving component 84 can be switched to the first state with a larger driving force, so that the driving component 84 outputs sufficient driving force to drive the first sliding body 82 or the second sliding body 83 to slide, and the first sliding body 82 or the second sliding body 83 drives the tie rod 3 to return to the normal state as a driving member.

[0135] When the rear wheel return device 8 does not need to drive the tie rod 3 to return to the normal state, the sliding body provides resistance, and the driving component 84 can be switched to the second state with a smaller driving force, so as to reduce the resistance to the tie rod 3 or the rear wheel steering driving device 2 and reduce the energy consumption of the rear wheel steering driving device 2. That is, in the second state, the first sliding body 82 or the second sliding body 83 slides under the driving of the rear wheel steering driving device 2 or the tie rod 3 of the rear wheel steering system.

[0136] The embodiments of the present disclosure do not limit the form of linkage between the sliding body and the tie rod 3, and the following is an exemplary description:

[0137] In some examples, as shown in the middle part of Figure 3 , Figure 5 or Figure 8 , when the first sliding body 82 and the second sliding body 83 are located at the first position and the second position respectively, the tie rod 3 is in the return state. Therefore, the driving component 84 can drive the tie rod 3 to return to the normal state by applying a driving force to the first sliding body 82 towards the first position and applying a driving force to the second sliding body 83 towards the second position, and can keep the tie rod 3 in the return state.

[0138] In some examples, as shown in Figure 3 , Figure 5 or Figure 8As shown in the upper part, when the first slider 82 is in the first position and the second slider 83 is between the first and second positions, the tie rod 3 is in a first offset state. Furthermore, the further the second slider 83 deviates from the second position (or, in other words, the closer it is to the first position), the greater the offset stroke of the tie rod 3. That is, in the first offset state, the first slider 82 is stable in the first position, and the second slider 83 is linked to the tie rod 3. Therefore, if it is necessary to drive the tie rod 3 back to the center position when it is in the first offset state, the drive component 84 is configured to drive the second slider 83 to slide towards the second position in the first state. Simultaneously, the drive component 84 can also be configured to drive the first slider 82 to remain stable in the first position in the first state.

[0139] In some examples, such as Figure 3 , Figure 5 or Figure 8 As shown in the lower part, when the first slider 82 is located between the first and second positions, and the second slider 83 is located in the second position, the tie rod 3 is in a second offset state. Furthermore, the further the first slider 82 deviates from the first position (or, in other words, the closer it is to the second position), the greater the offset stroke of the tie rod 3. That is, in the second offset state, the second slider 83 is stable in the second position, and the first slider 82 is linked with the tie rod 3. Therefore, if it is necessary to drive the tie rod 3 back to the center position when it is in the second offset state, the drive component 84 is configured to drive the first slider 82 to slide towards the first position in the first state. Simultaneously, the drive component 84 can also be configured to drive the second slider 83 to stabilize in the first position in the first state.

[0140] Among them, one of the first offset state and the second offset state is a left offset state, and the other is a right offset state.

[0141] Furthermore, according to the aforementioned description of the steering system, the rear wheel steering motor 21 can drive the tie rod 3 to move. Correspondingly, when the rear wheel return device 8 drives the tie rod 3 to return to center, the tie rod 3 will also drive the rear wheel steering motor 21 to rotate. At this time, the rear wheel steering motor 21 provides resistance to the movement of the tie rod 3. In some cases, the tie rod 3 may even fail to return to center properly because the rear wheel steering motor 21 may not be able to rotate.

[0142] To prevent the rear wheel steering motor 21 from affecting the rear wheel return mechanism 8's drive tie rod 3 for return to center, in some examples, such as Figure 2 , Figure 6 or Figure 7As shown, a clutch 223 can be installed on the drive shaft 22 between the rear wheel steering motor 21 and the reduction unit 23. In this way, before the rear wheel return device 8 drives the tie rod 3 to return to center, the clutch 223 is first disengaged to disconnect the mechanical connection between the tie rod 3 and the rear wheel steering motor 21, so that the rear wheel steering motor 21 will not obstruct the return of the tie rod 3 to center.

[0143] For example, such as Figure 2 As shown, the drive shaft 22 includes a first shaft section 221, a second shaft section 222, and a clutch 223. The first shaft section 221 and the second shaft section 222 are connected by the clutch 223. The second shaft section 222 is connected to the reduction unit 23, and the first shaft section 221 is connected to the rear wheel steering motor 21. Since the clutch 223 needs to be in a closed (or engaged) state when the rear wheel steering system is normal, a normally closed clutch can be selected for the clutch 223.

[0144] Furthermore, the drive component 84 provided in this embodiment can be controlled by the rear wheel steering control unit 1 to switch states, in which case the rear wheel steering control unit 1 is electrically connected to the drive component 84. Additionally, the rear wheel steering control unit 1 can also be electrically connected to the rear wheel steering motor 21, the clutch 223, and the travel sensor 25.

[0145] Among them, the rear wheel steering control unit 1 can be the rear wheel steering ECU 700, the vehicle control unit 100, or both the vehicle control unit 100 and the rear wheel steering ECU 700.

[0146] The present invention does not limit the position of the rear cycle positive device 8. The following is an exemplary description:

[0147] (1) In some examples, such as Figure 2 , Figure 3 or Figures 6-8 As shown, the rear wheel alignment device 8 is installed on the tie rod 3, so the rear wheel alignment device 8 can directly drive the tie rod 3 to return to center.

[0148] For example, such as Figure 2 , Figure 3 or Figures 6-8 As shown, the first sliding body 82 and the second sliding body 83 are ringed around the horizontal tie rod 3. The horizontal tie rod 3 has two first flanges 31, and the first sliding body 82 and the second sliding body 83 are located between the two first flanges 31. Figure 3 and Figure 8 As shown, when the first sliding body 82 and the second sliding body 83 are in the first position and the second position respectively, the first sliding body 82 and the second sliding body 83 are in contact with or abut against the two first flanges 31 respectively.

[0149] The process of the rear wheel steering drive unit 2 driving the tie rod 3 is as follows:

[0150] As shown in the middle part of FIG. 8A, assuming that the tie rod 3 is initially in the return state, the first sliding body 82 and the second sliding body 83 are in contact with the two first flanges 31 respectively. Figure 3 Figure 8 As shown in the middle part of FIG. 8A, assuming that the tie rod 3 is initially in the return state, the first sliding body 82 and the second sliding body 83 are in contact with the two first flanges 31 respectively.

[0151] When it is needed to move the tie rod 3 to the first offset state, as shown in the middle part to the upper part of FIG. 8B, the rear wheel steering drive device 2 drives the tie rod 3 to offset, and in the process of offsetting the tie rod 3, the first flange 31 on the tie rod 3 drives the second sliding body 83 to slide to the first position. At the same time, the first sliding body 82 remains in the first position. Figure 3 When it is needed to move the tie rod 3 to the second offset state, as shown in the middle part to the lower part of FIG. 8B, the rear wheel steering drive device 2 drives the tie rod 3 to offset, and in the process of offsetting the tie rod 3, the first flange 31 on the tie rod 3 drives the first sliding body 83 to slide to the second position. At the same time, the second sliding body 83 remains in the second position.

[0152] Figure 3 From the process of driving the tie rod 3 by the rear wheel steering drive device 2, it can be seen that in the first offset state, the second sliding body 83 hinders the movement of the tie rod 3, and in the second offset state, the first sliding body 82 hinders the movement of the tie rod 3.

[0153] In order to reduce the resistance received by the tie rod 3, in some examples, the driving component 84 can be configured to output a driving force of 0 in the second state.

[0154] In other examples, in order to make the second sliding body 83 tightly contact the corresponding first flange 31 in the process of switching from the first offset state to the return state, and make the first sliding body 82 tightly contact the corresponding first flange 31 in the process of switching from the second offset state to the return state, and avoid uncontrollable sliding of the first sliding body 82 and the second sliding body 83, the driving component 84 can be configured to apply a driving force to the first sliding body 82 in the second state, and apply a driving force to the second sliding body 83 in the second state.

[0155] It should be noted that the purpose of the driving component 84 outputting the driving force in the second state is not to make the sliding body become a driving component to drive the tie rod 3 to move, but to make the first sliding body 82 and the second sliding body 83 not to slide uncontrollably, so that the first sliding body 82 and the second sliding body 83 are either stably in the corresponding first position or second position, or tightly contact the first flange 31. Therefore, the driving force of the driving component 84 in the second state can be much smaller than the driving force in the first state.

[0156] It should be noted that the purpose of the driving component 84 outputting the driving force in the second state is not to make the sliding body become a driving component to drive the tie rod 3 to move, but to make the first sliding body 82 and the second sliding body 83 not to slide uncontrollably, so that the first sliding body 82 and the second sliding body 83 are either stably in the corresponding first position or second position, or tightly contact the first flange 31. Therefore, the driving force of the driving component 84 in the second state can be much smaller than the driving force in the first state.

[0157] ​​The process of the rear wheel return mechanism 8 driving the tie rod 3 to return to center is as follows:

[0158] like Figure 3 (or Figure 8 As shown in the upper part, assuming the tie rod 3 is in the first offset state and the rear wheel centering device 8 needs to drive the tie rod 3 back to center, the drive component 84 switches to the first state. Under the driving force of the drive component 84, the second sliding body 83 slides towards the second position. The second sliding body 83 drives the tie rod 3 back to center through the first flange 31 until it changes to the first offset state. Figure 3 The state shown in the middle section. At the same time, under the driving force of the driving component 84, the first sliding body 82 is stabilized in the first position.

[0159] like Figure 3 (or Figure 8 As shown in the lower part, assuming the tie rod 3 is in the second offset state and the rear wheel centering device 8 needs to drive the tie rod 3 back to center, the drive component 84 switches to the first state. Under the driving force of the drive component 84, the first sliding body 82 slides towards the first position. The first sliding body 82 drives the tie rod 3 back to center through the first flange 31 until it changes to the first offset state. Figure 3 The state shown in the middle section. At the same time, under the driving force of the driving component 84, the second sliding body 83 is stabilized in the second position.

[0160] (2) In other examples, such as Figure 4 As shown, the rear wheel return device 8 is mounted on the drive shaft 22 between the rear wheel steering motor 21 and the reduction unit 23. Since the rear wheel return device 8 is located at the input end of the reduction unit 23, it can drive the tie rod 3 back to center with less driving force. This reduces the driving force required for the rear wheel return device 8 in the first state, lowers its energy consumption, reduces its size, and makes it easier to arrange.

[0161] In some examples, such as Figure 5 As shown, the rear wheel return mechanism 8 includes a first lead screw 85 (or first screw rod) and a first nut 86. The first lead screw 85 is fixed on the drive shaft 22, and the first nut 86 is sleeved around the first lead screw 85. The first lead screw 85 and the first nut 86 form a lead screw-nut mechanism or a ball screw mechanism. The first nut 86 has two second flanges 861, and a first sliding body 82 and a second sliding body 83 are located between the two second flanges 861. When the first sliding body 82 and the second sliding body 83 are respectively in the first position and the second position, the first sliding body 82 and the second sliding body 83 are in contact with or abut against the two second flanges 861.

[0162] Furthermore, in some examples, such as Figure 5As shown, when the transmission shaft 22 comprises the clutch 223, the first screw rod 85 is fixed on the second shaft segment 222.

[0163] The process that the rear wheel steering driving device 2 drives the tie rod 3 is described as follows:

[0164] As shown in the middle part of FIG. 8, Figure 5 As shown in the middle part of FIG. 8,

[0165] When it is needed to offset the tie rod 3 to the first offset state, as shown in the middle part to the upper part of FIG. 8, Figure 5 the rear wheel steering motor 21 drives the transmission shaft 22 to rotate, the transmission shaft 22 drives the first screw rod 85 to rotate, and the first screw rod 85 drives the first nut 86 to slide. In the process that the first nut 86 slides, the first nut 86 drives the first sliding body 82 to slide to the second position through the second flange 861, and the second sliding body 83 remains in the first position. At the same time, the transmission shaft 22 also drives the tie rod 3 to offset to the first offset state through the speed reduction unit 23 and the conversion unit 24.

[0166] When it is needed to offset the tie rod 3 to the second offset state, as shown in the middle part to the lower part of FIG. 8, Figure 5 the rear wheel steering motor 21 drives the transmission shaft 22 to rotate, the transmission shaft 22 drives the first screw rod 85 to rotate, and the first screw rod 85 drives the first nut 86 to slide. In the process that the first nut 86 slides, the first nut 86 drives the first sliding body 82 to slide to the second position through the second flange 861, and the second sliding body 83 remains in the first position. At the same time, the transmission shaft 22 also drives the tie rod 3 to offset to the first offset state through the speed reduction unit 23 and the conversion unit 24.

[0167] From the process that the rear wheel steering driving device 2 drives the tie rod 3, it can be seen that in the first offset state, the second sliding body 83 hinders the sliding of the first nut 86, and in the second offset state, the first sliding body 82 hinders the sliding of the first nut 86.

[0168] In order to reduce the resistance that the first nut 86 receives, in some examples, the driving force that the driving component 84 outputs in the second state can be set to 0.

[0169] In some other examples, in order to make the second sliding body 83 tightly adhere to the corresponding second flange 861 in the process of switching from the first offset state to the back-to-normal state, and make the first sliding body 82 tightly adhere to the corresponding second flange 861 in the process of switching from the second offset state to the back-to-normal state, to avoid uncontrollable sliding of the first sliding body 82 and the second sliding body 83, the driving component 84 can also apply a driving force towards the first position to the first sliding body 82 and apply a driving force towards the second position to the second sliding body 83 in the second state.

[0170] It should be noted that the purpose of the driving component 84 outputting the driving force in the second state is not to make the sliding body become a driving component to drive the first nut 86 to slide, but to make the first sliding body 82 and the second sliding body 83 not uncontrollably slide, so that the first sliding body 82 and the second sliding body 83 are either stably in the corresponding first position or the second position, or tightly adhere to the second flange 861. Therefore, the driving force of the driving component 84 in the second state can be much smaller than the driving force in the first state.

[0171] The process of the rear wheel back-to-normal device 8 driving the tie rod 3 back to normal is as follows:

[0172] As shown in the upper part, Figure 5 assuming that the tie rod 3 is in the first offset state and needs to be driven back to normal by the rear wheel back-to-normal device 8. Then the driving component 84 switches to the first state, and under the action of the driving force of the driving component 84, the second sliding body 83 slides towards the second position, and at the same time drives the first nut 86 to slide towards the central position through the second flange 861, until it changes to the state shown in the middle part. In the process of sliding of the first nut 86, the first nut 86 drives the first lead screw 85 to rotate, the first lead screw 85 drives the transmission shaft 22 to rotate, and the transmission shaft 22 drives the tie rod 3 back to normal through the speed reduction unit 23 and the conversion unit 24. Figure 5

[0173] As shown in the lower part, Figure 5 assuming that the tie rod 3 is in the second offset state and needs to be driven back to normal by the rear wheel back-to-normal device 8. Then the driving component 84 switches to the first state, and under the action of the driving force of the driving component 84, the first sliding body 82 slides towards the first position, and at the same time drives the first nut 86 to slide towards the central position through the second flange 861, until it changes to the state shown in the middle part. In the process of sliding of the first nut 86, the first nut 86 drives the first lead screw 85 to rotate, the first lead screw 85 drives the transmission shaft 22 to rotate, and the transmission shaft 22 drives the tie rod 3 back to normal through the speed reduction unit 23 and the conversion unit 24. Figure 5

[0174] ​​The embodiments of the present disclosure do not limit the implementation of the driving component 84, as long as the driving component 84 can realize the first state and the second state with different driving forces. The implementation of the driving component 84 is exemplarily described as follows:

[0175] (1) In some examples, as shown in Figure 2 、 Figure 3 、 Figure 5 or Figure 6 , the driving component 84 includes a first electromagnetic coil 841 and a second electromagnetic coil 842, which are fixed inside the housing 81, and the first sliding body 82 and the second sliding body 83 are located between the first electromagnetic coil 841 and the second electromagnetic coil 842.

[0176] In some examples, as shown in Figure 2 、 Figure 3 、 Figure 5 or Figure 6 , the first electromagnetic coil 841 and the second electromagnetic coil 842 are respectively located at two ends of the housing 81.

[0177] In some examples, as shown in Figure 2 、 Figure 3 、 Figure 5 or Figure 6 , when the first sliding body 82 is located at the first position, the first electromagnetic coil 841 is in contact with the first sliding body 82, and when the second sliding body 83 is located at the second position, the second electromagnetic coil 842 is in contact with the second sliding body 83.

[0178] The driving component 84 can realize the first state and the second state with different driving forces by changing the size of the input current, or by energizing and de-energizing.

[0179] In the first state, the first electromagnetic coil 841 and the second electromagnetic coil 842 are energized, so that the first electromagnetic coil 841 and the second electromagnetic coil 842 generate electromagnetic force and attract the first sliding body 82 and the second sliding body 83 to slide to (or remain at) the first position and the second position, respectively.

[0180] In some examples, in the second state, the first electromagnetic coil 841 and the second electromagnetic coil 842 are also energized, but the input current is smaller than that in the first state.

[0181] In this way, in the second state, the first electromagnetic coil 841 applies a driving force to the first sliding body 82 towards the first position, and the second electromagnetic coil 842 applies a driving force to the second sliding body 83 towards the second position, so as to ensure that the first sliding body 82 and the second sliding body 83 will not slide uncontrollably.

[0182] In other examples, in the second state, the first electromagnetic coil 841 and the second electromagnetic coil 842 are powered off. In order to also enable the driving component 84 to output driving force in the second state in the case that the first electromagnetic coil 841 and the second electromagnetic coil 842 are powered off, in some examples, as shown in Figure 3 and Figure 5 shown, the driving component 84 further includes an elastic member 846, two ends of the elastic member 846 respectively abut against the first sliding body 82 and the second sliding body 83, and then the elastic member 846 applies driving force to the first sliding body 82 towards the first position and applies driving force to the second sliding body 83 towards the second position. The elastic member 846 can be a spring, which can be referred to as a return spring, and is used to drive the first sliding body 82 to slide to the first position and drive the second sliding body 83 to slide to the second position.

[0183] In this way, the first electromagnetic coil 841 and the second electromagnetic coil 842 do not need to be kept in the powered-on state all the time, which reduces energy consumption and improves the service life of the driving component 84.

[0184] (2) In some examples, the driving component 84 can also be a pneumatic driving component, which communicates with the chamber 80 between the first sliding body 82 and the second sliding body 83 and is capable of changing the driving force on the first sliding body 82 and the second sliding body 83 by changing the air pressure in the chamber 80, so as to realize different first states and second states.

[0185] In some examples, as shown in Figure 7 and Figure 8 shown, the driving component 84 includes an electromagnetic valve 843, which respectively communicates with a high-pressure gas circuit 844, a low-pressure gas circuit 845 on the vehicle, and the chamber 80 between the first sliding body 82 and the second sliding body 83.

[0186] In the first state, the electromagnetic valve 843 communicates the chamber 80 with the high-pressure gas circuit 844, and then the high-pressure gas flows into the chamber 80 through the high-pressure gas circuit 844 and pushes the first sliding body 82 or the second sliding body 83 to slide to the first position and the second position, respectively, and in the process of sliding, the first sliding body 82 or the second sliding body 83 drives the tie rod 3 to return to normal.

[0187] In the second state, the electromagnetic valve 843 communicates the chamber 80 with the low-pressure gas circuit 845, and then the high-pressure gas is discharged through the low-pressure gas circuit 845.

[0188] In some examples, after the chamber 80 is communicated with the low-pressure gas circuit 845, the gas in the chamber 80 is still capable of applying driving force to the first sliding body 82 towards the first position and applying driving force to the second sliding body 83 towards the second position, so as to ensure that the first sliding body 82 and the second sliding body 83 do not slide uncontrollably.

[0189] In some examples, the chamber 80 is communicated with the low-pressure air path 845 when the electromagnetic valve 843 is not powered, and the chamber 80 is communicated with the high-pressure air path 844 when the electromagnetic valve 843 is powered. In this way, the electromagnetic valve 843 can be powered for a small amount of time, which is conducive to reducing energy consumption.

[0190] In some examples, the chamber 80 is communicated with the low-pressure air path 845 when the electromagnetic valve 843 is not powered, and the chamber 80 is communicated with the high-pressure air path 844 when the electromagnetic valve 843 is powered. In this way, the electromagnetic valve 843 can be powered for a small amount of time, which is conducive to reducing energy consumption.

[0191] The embodiments of the present disclosure do not limit the sources of the high-pressure air path 844 and the low-pressure air path 845 on the vehicle. In some examples, the high-pressure air path 844 and the low-pressure air path 845 can be a separate air supply system arranged for the rear wheel alignment device 8.

[0192] In some examples, the high-pressure air path 844 and the low-pressure air path 845 can also reuse the air path of the air supply system 9 of the air suspension on the vehicle, without the need to arrange a separate air supply system.

[0193] Next, the air supply system 9 of the air suspension is exemplarily described.

[0194] As shown in Figure 9 The air supply system 9 includes a distribution valve 91, a high-pressure air path 844, a low-pressure air path 845, and an air supply system control unit 92. The high-pressure air path 844 has a high-pressure air tank 93, the low-pressure air path 845 is communicated with the atmosphere, and the air compressor 94 is arranged on the low-pressure air path 845. The air supply system control unit 92 is electrically connected with the air compressor 94 and the distribution valve 91 respectively.

[0195] The distribution valve 91 is communicated with the high-pressure air path 844, the low-pressure air path 845, and four air springs, and is used to communicate the high-pressure air path 844 or the low-pressure air path 845 with the four air springs. In addition, when the air pressure in the high-pressure air tank 93 is low, the air compressor 94 can be started and pressurized to the high-pressure air tank 93 through the distribution valve 91, or directly supply air to the four air springs.

[0196] The electromagnetic valve 843 provided by the embodiments of the present disclosure can be communicated with the high-pressure air path 844 and the low-pressure air path 845 of the air supply system 9, and communicated with the chamber 80 in the rear wheel alignment device 8. The electromagnetic valve 843 can be referred to as a two-position three-way electromagnetic valve.

[0197] In some examples, as shown in Figure 10As shown, the electromagnetic valve 843 can also be integrated with the distribution valve 91.

[0198] In some examples, in order to ensure the sealing of the chamber 80, as shown, a sealing ring 88 can be arranged between the first sliding body 82 and the housing 81, and between the second sliding body 83 and the housing 81, and a sealing ring 88 can be arranged between the first sliding body 82 and the tie rod 3, and between the second sliding body 83 and the tie rod 3. Figure 8

[0199] In addition, for the case where the rear wheel alignment device 8 is arranged on the transmission shaft 22 between the rear wheel steering motor 21 and the speed reduction unit 23, a sealing ring 88 can be arranged between the first sliding body 82 and the first nut 86, and between the second sliding body 83 and the first nut 86.

[0200] After the tie rod 3 is aligned by the rear wheel alignment device 8, it is also necessary to keep the tie rod 3 in the aligned state, so that the vehicle can be stably operated in the front wheel steering mode.

[0201] The embodiments of the present disclosure do not limit the implementation manner of keeping the tie rod 3 in the aligned state, and in some examples, the driving component 84 can be kept in the first state, so that the tie rod 3 is limited in the aligned state under the action of the driving force output by the driving component 84 in the first state.

[0202] In other examples, as shown, the rear wheel alignment device 8 further includes a brake 87, which is configured to lock the position of the tie rod 3 after the tie rod 3 is aligned.That is, the driving component 84 is used to drive the tie rod 3 to switch from the offset state to the aligned state, and the brake 87 is used to lock the position of the tie rod 3, so that the tie rod 3 is kept in the aligned state. The brake 87 can be an electromagnetic multi-plate brake. Figure 6 In this way, after the brake 87 locks the position of the tie rod 3, the driving component 84 can be switched to the second state, so as to reduce the energy consumption of the driving component 84. For example, when the driving component 84 includes a first electromagnetic coil 841 and a second electromagnetic coil 842, after the brake 87 locks the position of the tie rod 3, the first electromagnetic coil 841 and the second electromagnetic coil 842 can be switched from the energized state to the de-energized state.

[0203] The embodiments of the present disclosure do not limit the position where the brake 87 is arranged, and in some examples, as shown,

[0204] Figure 6 ​As shown in the figure, the brake 87 is arranged on the transmission shaft 22 between the rear wheel steering motor 21 and the speed reduction unit 23 of the rear wheel steering system, so when the brake 87 is braked, the transmission shaft 22 is locked and cannot rotate, and correspondingly, the speed reduction unit 23 and the conversion unit 24 cannot act, and the position of the tie rod 3 is locked.

[0205] Further, as shown in the figure, the brake 87 can be arranged on the second shaft section 222, so that after the clutch 223 is separated, the brake 87 can still lock the position of the tie rod 3. Figure 6

[0206] Of course, in other examples, the brake 87 can also be arranged on the first shaft section 221, and for this case, the clutch 223 needs to be controlled to be engaged first, and then the brake 87 can lock the position of the tie rod 3.

[0207] It should be noted that the brake 87 can also be considered to belong to the rear wheel steering driving device 2.

[0208] In addition to the above technical solutions of arranging the brake 87, in order to reduce the energy consumption of the driving part 84, in other examples, the driving part 84 can also be arranged to have a third state, and the driving force of the driving part 84 in the third state is greater than that in the second state and less than that in the first state. The driving part 84 is configured to drive the first sliding body 82 to remain in the first position and drive the second sliding body 83 to remain in the second position in the third state.

[0209] For example, when the driving part 84 includes a first electromagnetic coil 841 and a second electromagnetic coil 842, the currents flowing through the first electromagnetic coil 841 and the second electromagnetic coil 842 in the first state are greater than the currents flowing through the first electromagnetic coil 841 and the second electromagnetic coil 842 in the third state, so that the energy consumption of the driving part 84 in the third state is lower than that in the first state. Wherein, the currents flowing through the first electromagnetic coil 841 and the second electromagnetic coil 842 in the third state are greater than the currents flowing through the first electromagnetic coil 841 and the second electromagnetic coil 842 in the second state.

[0210] Next, the control logic of the tie rod 3 returning to the normal position is exemplarily described:

[0211] When the rear wheel steering system fails, in order to avoid the rear wheel from deflecting unexpectedly, the tie rod 3 needs to be controlled to return to the normal position, so that the vehicle is converted from four-wheel steering to front-wheel steering.

[0212] ​The return of the tie rod 3 can be driven by the rear wheel return device 8 or by the rear wheel steering drive device 2. Therefore, when the rear wheel steering system fails, it is necessary to determine whether the tie rod 3 is returned by the rear wheel return device 8 or by the rear wheel steering drive device 2.

[0213] In some examples, the failure state of the rear wheel steering system includes a first failure state and a second failure state.

[0214] The first failure state refers to a state in which the rear wheel steering drive device 2 cannot drive the tie rod 3 to return. When the rear wheel steering system is in the first failure state, it is determined that the tie rod 3 needs to be returned by the rear wheel return device 8. The first failure state can include a first sub-state and a second sub-state. The first sub-state refers to a state in which the rear wheel steering drive device 2 loses power, for example, the power supply of the rear wheel steering drive device 2 fails, or the rear wheel steering motor 21 of the rear wheel steering drive device 2 loses power. The second sub-state refers to a state in which the power of the rear wheel steering drive device 2 is normal, but the position of the tie rod 3 cannot be determined, for example, the sensor in the rear wheel steering drive device 2 for determining the position (or state) of the tie rod 3 fails, which can be a travel sensor 25.

[0215] The second failure state refers to a state in which the rear wheel steering system fails, but can still drive the tie rod 3 to return. When the rear wheel steering system is in the second failure state, the tie rod 3 can be driven to return by the rear wheel steering drive device 2 without the need for the rear wheel return device 8 to drive the tie rod 3 to return. In some examples, the second failure state includes a state in which the rear wheel steering motor 21 of the rear wheel steering drive device 2 is over-temperature or over-load, but has not lost power. In other examples, the second failure state includes a state in which the rear wheel steering control unit 1 cannot receive the rear wheel turning angle signal, for example, the communication between the rear wheel steering ECU 700 and the vehicle control unit 100 fails. In this state, the rear wheel steering control unit 1 cannot determine the required offset of the tie rod 3, but the rear wheel steering control unit 1 can control the tie rod 3 to return.

[0216] For ease of description, driving the tie rod 3 to return by the rear wheel return device 8 is referred to as failure handling mode 2, and driving the tie rod 3 to return by the rear wheel steering drive device 2 is referred to as failure handling mode 1.

[0217] Next, the rear wheel steering system will be described in conjunction with Figure 11 The flow of determining which failure handling mode to use is described as follows:

[0218] In step 1101, the rear wheel steering control unit 1 reads the failure information of the rear wheel steering system, and determines the failure handling mode to be used according to the read failure information.

[0219] In step 1102, it is determined whether the rear wheel steering motor 21 is overloaded or overheated. If so, fault handling mode 1 is adopted.

[0220] In step 1103, it is determined whether the communication of the rear wheel steering system is faulty (e.g., the rear wheel steering control unit 1 cannot receive the rear wheel angle signal). If so, it is determined to adopt fault handling mode 1.

[0221] In step 1104, it is determined whether the power supply of the rear wheel steering system is faulty. If so, fault handling mode 2 is adopted.

[0222] In step 1105, it is determined whether the stroke sensor 25 is faulty. If so, fault handling mode 2 is adopted.

[0223] In step 1106, it is determined whether the rear wheel steering motor 21 of the rear wheel steering system has a power failure (such as loss of power). If so, it is determined to adopt fault handling mode 2.

[0224] If it is determined that there are no faults in the rear wheel steering system, then normal rear wheel steering control is performed.

[0225] The following section, using the specific implementation of the rear cycle positive device 8 as an example, explains the processing flow of fault handling mode 1 and fault handling mode 2:

[0226] Fault handling mode 1:

[0227] like Figure 12 As shown, for the implementation of the rear wheel return device 8 excluding the brake 87, the fault handling mode 1 processing flow is as follows:

[0228] In step 1201, the rear wheel steering motor 21 actuates to return to the zero position. Since the rear wheel steering system may switch from the second fault state to the first fault state during the process of the rear wheel steering motor 21 returning to the zero position, steps 1202 and 1203 are executed during the operation of the rear wheel steering motor 21.

[0229] In step 1202, it is determined whether the stroke sensor 25 is normal. If it is not normal, switch to fault handling mode 2.

[0230] In step 1203, it is determined whether the rear wheel steering motor 21 has a power failure (loss of power). If so, switch to fault handling mode 2.

[0231] In step 1204, it is determined whether the tie rod 3 is centered. If it is not centered, the rear wheel steering motor 21 is controlled to continue to operate. If it is centered, the process ends.

[0232] like Figure 13As shown, for the implementation of the rear wheel return device 8 including the brake 87, the fault handling mode 1 processing flow is as follows:

[0233] The processing procedures for steps 1301 to 1303 are the same as those for steps 1201 to 1203, and will not be repeated here.

[0234] In step 1304, it is determined whether the tie rod 3 is centered. If it is not centered, the rear wheel steering motor 21 is controlled to continue to operate. If it is centered, the process proceeds to step 1305.

[0235] In step 1305, the brake 87 is locked, which locks the tie rod 3 in the return-to-center position. Afterwards, the rear wheel steering motor 21 can be turned off to reduce power consumption.

[0236] Fault handling mode 2:

[0237] like Figure 14 As shown, for the implementation of the drive component 84 including the first electromagnetic coil 841 and the second electromagnetic coil 842, and the rear wheel return device 8 excluding the brake 87, the processing flow of fault handling mode 2 is as follows:

[0238] In step 1401, clutch 223 disengages. This disconnects the rear wheel steering motor 21 from the reduction unit 23, and the rear wheel steering motor 21 no longer affects the movement of the rear wheel return mechanism 8 driving the tie rod 3.

[0239] In step 1402, the rear wheel steering motor 21 is de-energized. This reduces energy consumption and prevents the rear wheel steering motor 21 from rotating uncontrollably.

[0240] In step 1403, the electromagnetic coils are energized. That is, the drive component 84 switches to the first state, and the first electromagnetic coil 841 and the second electromagnetic coil 842 are energized. Under the magnetic attraction of the first electromagnetic coil 841 and the second electromagnetic coil 842, the horizontal pull rod 3 gradually returns to the center position.

[0241] In step 1404, it is determined whether the tie rod 3 has returned to its upright position. It should be noted that this determination can be made by the travel sensor 25. In the event of a malfunction of the travel sensor 25, the tie rod 3 can be determined to return to its upright position after a target duration of energization of the first electromagnetic coil 841 and the second electromagnetic coil 842. For example, this target duration can be 3s-10s. If it is determined that the tie rod 3 has not returned to its upright position, the electromagnetic coils are kept energized. If it is determined that the tie rod 3 has returned to its upright position, the process proceeds to step 1405.

[0242] In step 1405, the electromagnetic coil remains energized. In some examples, the current energizing the electromagnetic coil in step 1405 is the same as the current energizing the electromagnetic coil in step 1403; that is, the drive component 84 remains in the first state in step 1405. In other examples, the current energizing the electromagnetic coil in step 1405 is less than the current energizing the electromagnetic coil in step 1403; that is, the drive component 84 remains in the third state in step 1405, and in the first state in step 1403.

[0243] like Figure 15 As shown, for the implementation of the drive component 84 including a first electromagnetic coil 841 and a second electromagnetic coil 842, and the rear wheel return-to-center device 8 including a brake 87, the processing flow of fault handling mode 2 is as follows:

[0244] The processing procedures for steps 1501 to 1503 are the same as those for steps 1401 to 1403, and will not be repeated here.

[0245] In step 1504, it is determined whether the tie rod 3 has returned to its upright position. It should be noted that this determination can be made by the travel sensor 25. In the event of a malfunction of the travel sensor 25, the tie rod 3 can be determined to return to its upright position after a target duration of energization of the first electromagnetic coil 841 and the second electromagnetic coil 842. For example, this target duration can be 3s-10s. If it is determined that the tie rod 3 has not returned to its upright position, the electromagnetic coils are kept energized. If it is determined that the tie rod 3 has returned to its upright position, the process proceeds to step 1505.

[0246] In step 1505, the brake 87 is locked, thus locking the horizontal tie rod 3 in the return-to-center state. Afterwards, the first electromagnetic coil 841 and the second electromagnetic coil 842 can be de-energized, thereby reducing the power consumption of the drive component 84.

[0247] like Figure 16 As shown, for the implementation of the drive component 84 including the solenoid valve 843, the fault handling mode 2 processing flow is as follows:

[0248] In step 1601, clutch 223 disengages. This disconnects the rear wheel steering motor 21 from the reduction unit 23, and the rear wheel steering motor 21 no longer affects the movement of the rear wheel return mechanism 8 driving the tie rod 3.

[0249] In step 1602, the rear wheel steering motor 21 is de-energized. This reduces energy consumption and prevents the rear wheel steering motor 21 from rotating uncontrollably.

[0250] In step 1603, the electromagnetic valve 843 is energized. The chamber 80 of the rear wheel straightening device 8 is communicated with the high-pressure gas circuit 844, and under the action of high-pressure gas, the first sliding body 82 or the second sliding body 83 drives the track rod 3 to straighten.

[0251] In step 1604, the pressure is locked. The chamber 80 of the rear wheel straightening device 8 is kept in communication with the high-pressure gas circuit 844, and under the action of high-pressure gas, the first sliding body 82 and the second sliding body 83 are kept in the first position and the second position respectively, and the track rod 3 is kept in the straightening state.

[0252] As shown in Figure 17 For the implementation mode of the electromagnetic valve 843 multiplexing the air suspension supply system 9, the processing flow of the fault handling mode 2 is as follows:

[0253] In step 1701, the clutch 223 is separated. In this way, the rear wheel steering motor 21 is disconnected with the speed reduction unit 23, and the rear wheel steering motor 21 will not affect the movement of the track rod 3 driven by the rear wheel straightening device 8.

[0254] In step 1702, the rear wheel steering motor 21 is de-energized. In this way, the energy consumption is reduced, and the uncontrolled rotation of the rear wheel steering motor 21 is prevented.

[0255] In step 1703, the electromagnetic valve 843 is energized.

[0256] In step 1704, it is determined whether the pressure of the high-pressure gas tank 93 reaches the threshold value. If the threshold value is reached, the processing of step 1705 is executed, and if the threshold value is not reached, the processing of step 1707 is executed.

[0257] In step 1705, the electromagnetic valve 843 is connected to the high-pressure gas tank 93, and then the high-pressure gas flows into the chamber 80 of the rear wheel straightening device 8 through the electromagnetic valve 843, and under the action of high-pressure gas, the first sliding body 82 or the second sliding body 83 drives the track rod 3 to straighten.

[0258] In step 1706, the pressure is locked. The chamber 80 of the rear wheel straightening device 8 is communicated with the high-pressure gas tank 93 or the working air compressor 94, and under the action of high-pressure gas, the first sliding body 82 and the second sliding body 83 are kept in the first position and the second position respectively, and the track rod 3 is kept in the straightening state.

[0259] In step 1707, the electromagnetic valve 843 is connected to the air compressor 94.

[0260] In step 1708, the air compressor 94 is started, and the high-pressure gas in the air compressor 94 flows into the chamber 80 of the rear wheel straightening device 8 through the electromagnetic valve 843, and under the action of high-pressure gas, the first sliding body 82 or the second sliding body 83 drives the track rod 3 to straighten.

[0261] It should be noted that when the tie rod 3 is in the straightening state, the rear wheels are also straightened. The straightening state can also be referred to as a centering state.

[0262] The embodiments of the present disclosure also provide a rear wheel steering system, which comprises a rear wheel steering control unit 1, a rear wheel steering driving device 2, a tie rod 3 and a rear wheel straightening device 8, as shown in Figure 2 、 Figure 4 、 Figure 6 and Figure 7 The rear wheel steering driving device 2 is in driving connection with the tie rod 3.

[0263] The rear wheel steering control unit 1 can comprise at least one of a whole vehicle control unit 100 and a rear wheel steering ECU 700.

[0264] The rear wheel steering driving device 2 comprises a rear wheel steering motor 21, a transmission shaft 22, a speed reduction unit 23, a conversion unit 24 and a stroke sensor 25. The rear wheel steering motor 21 can be a brushless motor. The rear wheel steering motor 21 is connected with the speed reduction unit 23 through the transmission shaft 22. The speed reduction unit 23 is connected with the conversion unit 24. The conversion unit 24 is connected with the tie rod 3. The conversion unit 24 is used to convert rotation into linear motion of the tie rod 3, so as to realize driving the tie rod 3 to move by the rear wheel steering motor 21. The stroke sensor 25 is arranged on the tie rod 3. The stroke sensor 25 is used to detect the position of the tie rod 3.

[0265] In some examples, the rear wheel steering system further comprises a left connecting assembly 4 and a right connecting assembly 5. Two ends of the tie rod 3 are connected with the left connecting assembly 4 and the right connecting assembly 5 respectively.

[0266] The left connecting assembly 4 and the right connecting assembly 5 are respectively used to connect with a left rear wheel 6 and a right rear wheel 7. The left connecting assembly 4 comprises a left steering drag link 41 and a left steering knuckle arm 42. The right connecting assembly 5 comprises a right steering drag link 51 and a right steering knuckle arm 52. When the tie rod 3 moves, the tie rod 3 drives the left rear wheel 6 and the right rear wheel 7 to steer through the left connecting assembly 4 and the right connecting assembly 5 respectively.

[0267] In some examples, the rear wheel steering system further comprises the left rear wheel 6 and the right rear wheel 7.

[0268] The specific implementation modes of the rear wheel steering driving device 2, the tie rod 3, the left connecting assembly 4, the right connecting assembly 5, the left rear wheel 6, the right rear wheel 7 and the rear wheel straightening device 8 can be referred to the foregoing content, which will not be described here.

[0269] In some examples, the rear wheel steering control unit 1 is configured to determine that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten, and control the driving component 84 to switch to the first state. In the first state, the driving component 84 drives the first sliding body 82 or the second sliding body 83 to slide, and the first sliding body 82 or the second sliding body 83 drives the tie rod 3 to straighten.

[0270] The embodiments of the present disclosure do not limit the state of the rear wheel steering system in which the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten. In some examples, the rear wheel steering control unit 1 is configured to determine that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten when it is determined that the rear wheel steering system is faulty. That is, as long as the rear wheel steering system is faulty, it is determined that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten.

[0271] In other examples, it can also be that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten only when it is determined that the rear wheel steering system is in a certain faulty state. The following is an exemplary illustration:

[0272] In some examples, the faulty state of the rear wheel steering system includes a first faulty state and a second faulty state.

[0273] The first faulty state refers to a state in which the rear wheel steering driving device 2 cannot drive the tie rod 3 to straighten. When the rear wheel steering system is in the first faulty state, the rear wheel steering control unit 1 can determine that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten. The first faulty state can include a first sub-state and a second sub-state. The first sub-state refers to a state in which the rear wheel steering driving device 2 loses power (loses power), for example, a power failure of the rear wheel steering driving device 2, or a power failure (loses power) of the rear wheel steering motor 21. The second sub-state refers to a state in which the rear wheel steering driving device 2 has normal power, but cannot determine the position of the tie rod 3, for example, a sensor failure of the rear wheel steering driving device 2, which is used to determine the position of the tie rod 3. The sensor can be a stroke sensor 25.

[0274] The second faulty state refers to a state in which the rear wheel steering system is faulty, but can still drive the tie rod 3 to straighten. When the rear wheel steering system is in the second faulty state, the rear wheel steering control unit 1 can be configured to control the rear wheel steering driving device 2 to drive the tie rod 3 to straighten. In some examples, the second faulty state includes a state in which the rear wheel steering motor 21 of the rear wheel steering driving device 2 is over-temperature or over-load, but has not lost power. In other examples, the second faulty state includes a state in which the rear wheel steering control unit 1 cannot receive the rear wheel steering angle signal.

[0275] After the rear wheel return device 8 or the rear wheel steering drive device 2 drives the tie rod 3 back to center, it is also necessary to keep the tie rod 3 in the returned state. The following is an illustrative example of how to keep the tie rod 3 in the returned state:

[0276] In some examples, when the rear wheel return device 8 includes a brake 87, after the rear wheel steering control unit 1 determines that the tie rod 3 is in the return state, it controls the brake 87 to lock the position of the tie rod 3, so that the tie rod 3 remains in the return state under the action of the brake 87.

[0277] When the tie rod 3 is driven back to center by the rear wheel return device 8, after the brake 87 locks the position of the tie rod 3, the rear wheel steering control unit 1 can control the drive component 84 in the rear wheel return device 8 to switch to a second state, for example, by controlling the first electromagnetic coil 841 and the second electromagnetic coil 842 to be de-energized. This reduces the energy consumption of the drive component 84.

[0278] When the tie rod 3 is driven back to center by the rear wheel steering drive device 2, after the brake 87 locks the position of the tie rod 3, the rear wheel steering control unit 1 can control the rear wheel steering motor 21 to shut down, so as to reduce the energy consumption of the rear wheel steering motor 21.

[0279] In some examples, when the drive unit 84 is in the third state, after the rear wheel steering control unit 1 determines that the tie rod 3 is in the return-to-center state, it controls the drive unit 84 to switch to the third state so that the tie rod 3 remains in the return-to-center state and reduces the power consumption of the drive unit 84. For example, by reducing the current in the first electromagnetic coil 841 and the second electromagnetic coil 842.

[0280] In some examples, after the rear wheel steering control unit 1 determines that the tie rod 3 is in the return-to-center state, it can also control the drive component 84 to remain in the first state so that the tie rod 3 remains in the return-to-center state. For example, the current in the first electromagnetic coil 841 and the second electromagnetic coil 842 is kept constant. As another example, high-pressure gas is always supplied to the chamber 80 between the first slider 82 and the second slider 83.

[0281] In addition, such as Figure 6 As shown, in the case where the drive shaft 22 has a clutch 223, in order to prevent the rear wheel steering motor 21 from obstructing the rear wheel return device 8 from driving the tie rod 3 back to center, the rear wheel steering control unit 1 is also configured to control the clutch 223 to disengage before the control drive component 84 switches to the first state.

[0282] This disclosure also provides a rear wheel steering control method, which is applied in the rear wheel steering control unit 1 of the rear wheel steering system, such as... Figure 18 As shown, the control methods include:

[0283] In step 1801, it is determined that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten.

[0284] The embodiments of the present disclosure do not limit the state of the rear wheel steering system in which the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten. In some examples, the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten when it is determined that the rear wheel steering system is faulty. That is, as long as the rear wheel steering system is faulty, the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten.

[0285] In other examples, the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten only when the rear wheel steering system is in certain faulty states. The following is an exemplary illustration:

[0286] In some examples, the faulty states of the rear wheel steering system include a first faulty state and a second faulty state.

[0287] The first faulty state refers to a state in which the rear wheel steering drive device 2 cannot drive the tie rod 3 to straighten. When the rear wheel steering system is in the first faulty state, the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten. The first faulty state can include a first sub-state and a second sub-state. The first sub-state refers to a state in which the rear wheel steering drive device 2 loses power (or power loss), for example, the power supply of the rear wheel steering drive device 2 is faulty, or the rear wheel steering motor 21 of the rear wheel steering drive device 2 loses power. The second sub-state refers to a state in which the rear wheel steering drive device 2 has normal power, but cannot determine the position of the tie rod 3, for example, the sensor of the rear wheel steering drive device 2 for determining the position of the tie rod 3 is faulty, and the sensor can be a travel sensor 25.

[0288] The second faulty state refers to a state in which the rear wheel steering system is faulty, but can still drive the tie rod 3 to straighten. When the rear wheel steering system is in the second faulty state, the rear wheel steering drive device 2 can be controlled to drive the tie rod 3 to straighten, without the need for the rear wheel straightening device 8 to drive the tie rod 3 to straighten. In some examples, the second faulty state includes a state in which the rear wheel steering motor 21 of the rear wheel steering drive device 2 is over-temperature or over-load, but has not lost power. In other examples, the second faulty state includes a state in which the rear wheel steering control unit 1 cannot receive the rear wheel angle signal.

[0289] In step 1802, the driving component 84 is controlled to switch to the first state.

[0290] After the driving component 84 is switched to the first state, the driving component 84 drives the first sliding body 82 or the second sliding body 83 to slide, and the second sliding body 83 or the second sliding body 83 drives the tie rod 3 to straighten.

[0291] Of course, if it is determined that the tie rod 3 needs to be returned by the rear wheel returning device 2, the rear wheel returning device 2 returns the tie rod 3.

[0292] After the tie rod 3 is returned by the rear wheel returning device 8 or the rear wheel steering driving device 2, it is also necessary to keep the tie rod 3 in the returned state. Hereinafter, the implementation of keeping the tie rod 3 in the returned state is exemplarily described.

[0293] In some examples, when the rear wheel returning device 8 further comprises a brake 87, after it is determined that the tie rod 3 is in the returned state, the brake 87 is controlled to lock the position of the tie rod 3. Thus, under the action of the brake 87, the tie rod 3 is kept in the returned state.

[0294] For the case that the tie rod 3 is returned by the rear wheel returning device 8, after the brake 87 locks the position of the tie rod 3, the driving component 84 can be controlled to switch to the second state, for example, the first electromagnetic coil 841 and the second electromagnetic coil 842 are controlled to be powered off, so as to reduce the power consumption of the driving component 84.

[0295] For the case that the tie rod 3 is returned by the rear wheel steering driving device 2, after the brake 87 locks the position of the tie rod 3, the rear wheel steering motor 21 can be controlled to be powered off, so as to reduce the power consumption of the rear wheel steering motor 21.

[0296] In some examples, when the driving component 84 has a third state, after it is determined that the tie rod 3 is in the returned state, the driving component 84 is controlled to switch to the third state, so as to keep the tie rod 3 in the returned state and reduce the power consumption of the driving component 84. For example, the current in the first electromagnetic coil 841 and the second electromagnetic coil 842 is reduced.

[0297] In some examples, after it is determined that the tie rod 3 is in the returned state, the driving component 84 can also be controlled to keep in the first state, so as to keep the tie rod 3 in the returned state. For example, the current in the first electromagnetic coil 841 and the second electromagnetic coil 842 is kept unchanged. For another example, the chamber 80 between the first sliding body 82 and the second sliding body 83 is kept always connected to the high-pressure gas.

[0298] In addition, as shown in Figure 6 For the case that the transmission shaft 22 has the clutch 223, in order to avoid the rear wheel steering motor 21 affecting the tie rod 3 returned by the rear wheel returning device 8, before the driving component 84 is controlled to switch to the first state, the clutch 223 is controlled to be separated.

[0299] It should be noted that the detailed content of the control method of the rear wheel returning can refer to the foregoing related content of the rear wheel returning device 8 and the rear wheel steering system.

[0300] The embodiments of the present disclosure also provide a rear wheel straightening control device. The control device is located in a rear wheel steering control unit 1 of a rear wheel steering system, as shown in the figure. The control device comprises: Figure 19

[0301] A determination module 1901 is configured to determine that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten.

[0302] A control module 1902 is configured to control the driving component 84 to switch to the first state.

[0303] In some examples, the determination module 1901 is configured to determine that the rear wheel straightening device 8 needs to drive the tie rod 3 to straighten when it is determined that the rear wheel steering system is in a first fault state.

[0304] The first fault state comprises one or more of the following states: power failure of the rear wheel steering driving device 2, power failure of the rear wheel steering motor 21 of the rear wheel steering driving device 2, and sensor failure of the rear wheel steering driving device 2, which is used to determine the position of the tie rod 3.

[0305] In some examples, when the rear wheel straightening device 8 further comprises a brake 87, after the control module 1902 controls the driving component 84 to switch to the first state, the determination module 1901 is further configured to determine that the tie rod 3 is in a straightening state. The control module 1902 is further configured to control the brake 87 to lock the position of the tie rod 3, and control the driving component 84 to switch to the second state.

[0306] In some examples, when the driving component 84 has a third state, after the control module 1902 controls the driving component 84 to switch to the first state, the determination module 1901 is further configured to determine that the tie rod 3 is in a straightening state. The control module 1902 is further configured to control the driving component 84 to switch to the third state.

[0307] In some examples, when the rear wheel steering driving device 2 comprises a clutch 223, before the control module 1902 controls the driving component 84 to switch to the first state, the control module 1902 is further configured to control the clutch 223 to separate.

[0308] In some examples, the determination module 1901 is further configured to determine that the rear wheel steering system is in a second fault state.

[0309] The control module 1902 is further configured to control the rear wheel steering driving device 2 to drive the tie rod 3 to straighten.

[0310] The second fault state comprises one or more of the following states: over-temperature or overload of the rear wheel steering motor 21 of the rear wheel steering driving device 2, and the rear wheel steering control unit 1 being unable to receive a rear wheel steering angle signal.

[0311] ​The embodiments of the present disclosure further provide an electronic control unit, comprising a controller, and a memory coupled with the controller, wherein the memory stores at least one instruction loaded and executed by the controller to implement the rear wheel turning control method.

[0312] The electronic control unit can be the rear wheel turning control unit 1.

[0313] Referring to Figure 20 , Figure 20 A structure diagram of an electronic control unit 2000 provided by the embodiments of the present disclosure is shown. Figure 20 The electronic control unit 2000 shown can be the rear wheel turning control unit 1.

[0314] As Figure 20 shown, the electronic control unit 2000 comprises at least one processor 2001 (or referred to as a controller), a memory 2002, and at least one communication interface 2003.

[0315] The processor 2001 is, for example, a central processing unit (CPU), a digital signal processor (DSP), a network processor (NP), a graphics processing unit (GPU), a neural-network processing units (NPU), a data processing unit (DPU), a microcontroller, or one or more integrated circuits used to implement embodiments of the present disclosure. For example, the processor 2001 includes an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or other programmable logic device, transistor logic, a hardware component, or any combination thereof. The PLD is, for example, a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. It can implement or execute various logical blocks, modules, and circuits described in connection with the disclosure of the embodiments of the present disclosure. The processor 2001 can also be a combination of implementing computing functions, such as including one or more microcontroller combinations, a combination of a DSP and a microcontroller, and the like.

[0316] In some examples, the electronic control unit 2000 also includes a bus. The bus is used to transmit information between the components of the electronic control unit 2000. The bus can be a peripheral component interconnect (PCI) bus or a PCIe bus, an extended industry standard architecture (EISA) bus, or the like. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 20 In the figure, only one thick line is used to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0317] The memory 2002 is, for example, a read-only memory (ROM) or other type of static storage device that can store static information and instructions; a random access memory (RAM), or other type of dynamic storage device that can store information and instructions; a flash memory or other optical disk storage, including a compact disc read-only memory (CD-ROM), a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, and the like; a magnetic storage device or other magnetic storage device, including a magnetic disk storage or other magnetic storage devices; or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a computer, but is not limited to. The memory 2002 is, for example, independently present and connected to the processor 2001 through a bus. The memory 2002 can also be integrated with the processor 2001.

[0318] The communication interface 2003 uses any transceiver-like mechanism for communicating with other devices or a communication network, which can be an Ethernet, a radio access network (RAN), a wireless local area network (WLAN), and the like. The communication interface 2003 can include a wired communication interface and can also include a wireless communication interface. Specifically, the communication interface 2003 can be an Ethernet interface, a fast Ethernet (FE) interface, a gigabit Ethernet (GE) interface, an asynchronous transfer mode (ATM) interface, a WLAN interface, a cellular network communication interface, or a combination thereof. The Ethernet interface can be an optical interface, an electrical interface, or a combination thereof. In the embodiments of the present disclosure, the communication interface 2003 can be used for the electronic control unit 2000 to communicate with other devices.

[0319] In some examples, the processor 2001 can include one or more CPUs, such as the CPU0 and the CPU1 shown in FIG. 1. Each of these processors can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions). Figure 20

[0320] In some examples, the electronic control unit 2000 can include multiple processors, such as the processor 2001 and the processor 2002 shown in FIG. 1. Each of these processors can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).​Figure 20 Each of these processors can be a single-core controller or a multiple-core controller. A processor here can refer to one or more devices, circuits, and / or processing cores for processing data, such as computer program instructions.

[0321] In some examples, the electronic control unit 2000 can also include an output device and an input device. The output device is in communication with the processor 2001 and can display information in a variety of ways. For example, the output device can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device is in communication with the processor 2001 and can receive user input in a variety of ways. For example, the input device can be a mouse, a keyboard, a touch screen device, or a sensor device, etc.

[0322] In some examples, the memory 2002 is configured to store program code 2010 for implementing the embodiments of the present disclosure, and the processor 2001 can execute the program code 2010 stored in the memory 2002. One or more software modules can be included in the program code 2010. Alternatively, the processor 2001 itself can also store program codes or instructions for implementing the embodiments of the present disclosure.

[0323] wherein, Figure 18 The steps performed by the control method for rear wheel alignment correction shown above are completed by the integrated logic circuit of the processor 2001 or the instructions in the form of software. The steps of the method disclosed in combination with the embodiments of the present disclosure can be directly embodied as hardware controllers for execution, or executed by a combination of hardware and software modules in the controller. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the memory, and the controller reads the information in the memory, and combines the hardware to complete the steps of the above method. To avoid repetition, it will not be described in detail here.

[0324] The embodiments of the present disclosure further provide another electronic control unit, which can be the rear wheel steering control unit 1. The electronic control unit comprises a transceiver, a memory and a controller. The transceiver, the memory and the controller communicate with each other through internal connection paths. The memory is configured to store instructions. The controller is configured to execute the instructions stored in the memory to control the transceiver to receive signals and control the transceiver to send signals. When the controller executes the instructions stored in the memory, the controller executes the control method of the rear wheel steering.

[0325] It should be understood that the controller described above can be a central controller, and can also be other general-purpose controllers, digital signal controllers, ASICs, FPGAs or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose controller can be a microcontroller or any conventional controller, etc. It is worth noting that the controller can be an advanced RISC machine (ARM) architecture controller.

[0326] Further, in some examples, the memory described above can include read-only memory and random access memory, and provide instructions and data to the controller. The memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0327] The memory can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, and not limitation, many forms of RAM can be used. For example, a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), a double data rate synchronous DRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchlink DRAM (SLDRAM), and a direct Rambus RAM (DR RAM) can be used.

[0328] The embodiment of the present disclosure further provides a computer readable storage medium, and at least one instruction is stored in the computer readable storage medium. The instruction is loaded and executed by a controller, so that the controller implements the rear wheel turning control method.

[0329] The embodiment of the present disclosure further provides a computer program product, when the computer program product is executed by an electronic control unit (such as the rear wheel turning control unit 1), the electronic control unit can execute the corresponding steps and / or processes in the above method embodiment.

[0330] The embodiment of the present disclosure further provides a chip, and the chip includes a controller. The controller is used to call and run instructions stored in a memory, so that an electronic control unit (such as the rear wheel turning control unit 1) installed with the chip executes the rear wheel turning control method.

[0331] The embodiment of the present disclosure further provides another chip, and the chip includes an input interface, an output interface, a controller and a memory. The input interface, the output interface, the controller and the memory are connected through internal connection paths. The controller is used to execute code in the memory. When the code is executed, the controller is used to execute the rear wheel turning control method.

[0332] In the embodiments described above, the entire or part of the embodiments can be realized by one or more of software, hardware, firmware or any combination thereof. When realized by software, the entire or part of the embodiments can be realized as a computer program product. The computer program product includes one or more computer instructions. When loaded and executed by a computer (electronic control unit), the computer program instructions cause the processes or functions described in the embodiments of the present disclosure to be performed entirely or partially. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transferred from one website site, computer, server or data center to another website site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, Solid State Disk) and the like.

[0333] In order to clearly illustrate the interchangeability of hardware and software, the steps and components of the embodiments have been described in the above description in general terms. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present disclosure.

[0334] The computer program code for implementing the method of the embodiments of the present disclosure can be written in one or more programming languages. These computer program codes can be provided to a general-purpose computer, a special-purpose computer, or other programmable controller, so that when the program codes are executed by the computer or other programmable controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the computer, partially on the computer, as a separate software package, partially on the computer and partially on a remote computer, or entirely on a remote computer or server.

[0335] In the context of the embodiments of the present disclosure, the computer program code or related data can be carried by any appropriate carrier to enable the device, apparatus or controller to perform the various processes and operations described above. Examples of the carrier include a signal, a computer readable medium, etc. Examples of the signal can include electrical, optical, radio, sound or other forms of propagated signals, such as carrier waves, infrared signals, etc.

[0336] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and module can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0337] In several embodiments provided in the present disclosure, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be indirect coupling or communication connection through some interfaces, devices or modules, and can also be electrical, mechanical or other forms of connection.

[0338] The modules described as separate components can or can not be physically separated, and the components shown as modules can or can not be physical modules, that is, they can be located in one place, or can be distributed to a plurality of network modules. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment of the present disclosure.

[0339] In addition, each functional module in each embodiment of the present disclosure can be integrated into a processing module, or each module can exist physically, or two or more modules can be integrated into one module. The above integrated module can be realized in the form of hardware or in the form of software functional module.

[0340] In the present disclosure, the terms "first", "second", and the like are used to distinguish between the same items or similar items with substantially the same function and should be understood that there is no logical or time sequence relationship between "first", "second", "nth", and the like, and the quantity and execution order are not limited. It should also be understood that although the following description uses the terms first, second, and the like to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another.

[0341] It should also be understood that in various embodiments of the present disclosure, the size of the serial number of each process does not mean the execution order, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure.

[0342] In the present disclosure, the term "at least one" means one or more, and the term "multiple" in the present disclosure means two or more.

[0343] It should be understood that the words “example” and / or “exemplary” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described in this specification as “example” and / or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words “example” and / or “exemplary” is intended to present concepts in a concrete fashion. As used in this specification and the appended drawings, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean that X employs A or B or both A and B. In addition, the words “a” and “an” as used in this specification does not

[0344] It should also be understood that, depending on the specific context, the word “comprise” or variations such as “comprises” or “comprising” will be understood to encompass the terms “include” or “including” and the phrase “consist of’ or variations such as “consists of’ or “consisting of’.

[0345] It should also be understood that the phrase “if determined” or “if detected [stated condition or event]” can be interpreted to mean “upon determining” or “in response to determining” or “upon detecting” or “in response to detecting” [stated condition or event], depending on the context.

[0346] It should be understood that a determination of B according to A does not mean that B is determined only according to A, but B can also be determined according to A and / or other information.

[0347] It should also be understood that the description throughout this specification uses “one embodiment”, “an embodiment”, “some embodiments” and “a possible implementation” to mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation is included in at least one embodiment of the disclosure. Thus, appearances of the phrases “in one embodiment” or “in an embodiment”, “in some embodiments” or “in one possible implementation”, at various places in the specification are not necessarily referring to the same embodiment or implementation. Furthermore, the particular features, structures or characteristics can be combined in any suitable manner in one or more embodiments.

[0348] The above description is merely illustrative of the exemplary embodiments of this disclosure, and is not intended to limit the scope of the disclosure. Any modification, equivalent replacement, improvement, and the like made within the principles of the disclosure should be included in the scope of the disclosure.

Claims

1. A rear cycle positive device, characterized in that, The rear wheel return device includes a housing (81), a first sliding body (82), a second sliding body (83), and a drive component (84). The housing (81) is used to secure it to the vehicle; The first sliding body (82) and the second sliding body (83) are located inside the housing (81). The first sliding body (82) and the second sliding body (83) are located between two flanges. The first sliding body (82) and the second sliding body (83) are linked with the tie rod (3) of the rear wheel steering system. When the first sliding body (82) and the second sliding body (83) are respectively in the first position and the second position, the first sliding body (82) and the second sliding body (83) are respectively in contact with the two flanges, and the tie rod (3) is in the return state. The driving component (84) is configured to apply a driving force toward the first position to the first sliding body (82) and a driving force toward the second position to the second sliding body (83). The driving component (84) has a first state and a second state, wherein the driving force of the driving component (84) in the first state is greater than the driving force in the second state. In the first state, the driving component (84) drives the first sliding body (82) to slide to the first position or drives the second sliding body (83) to slide to the second position, and the first sliding body (82) or the second sliding body (83) drives the crossbar (3) to return to the center position through the corresponding flange; In the second state, the first slider (82) is located in the first position, and the second slider (83) slides between the first position and the second position following the corresponding flange; or, the second slider (83) is located in the second position, and the first slider (82) slides between the first position and the second position following the corresponding flange.

2. The rear cycle positive device according to claim 1, characterized in that, The first sliding body (82) and the second sliding body (83) are looped around the horizontal tie rod (3), and the horizontal tie rod (3) has the two flanges.

3. The rear cycle positive device according to claim 1, characterized in that, The rear wheel return mechanism also includes a first lead screw (85) and a first nut (86). The first lead screw (85) is fixed on the transmission shaft (22) between the rear wheel steering motor (21) and the reduction unit (23) of the rear wheel steering system, and the first nut (86) is looped around the first lead screw (85). The first nut (86) has the two flanges.

4. The rear cycle positive device according to claim 3, characterized in that, The drive shaft (22) includes a first shaft section (221), a second shaft section (222), and a clutch (223), wherein the first shaft section (221) and the second shaft section (222) are connected by the clutch (223); The second shaft segment (222) is connected to the reduction unit (23), and the first lead screw (85) is fixed on the second shaft segment (222).

5. The rear cycle positive device according to claim 1, characterized in that, The driving component (84) includes a first electromagnetic coil (841) and a second electromagnetic coil (842). The first electromagnetic coil (841) and the second electromagnetic coil (842) are fixed inside the housing (81), and the first sliding body (82) and the second sliding body (83) are located between the first electromagnetic coil (841) and the second electromagnetic coil (842); In the first state, the first electromagnetic coil (841) and the second electromagnetic coil (842) are energized, and the first electromagnetic coil (841) and the second electromagnetic coil (842) attract the first sliding body (82) and the second sliding body (83) respectively.

6. The rear cycle positive device according to claim 5, characterized in that, In the second state, the first electromagnetic coil (841) and the second electromagnetic coil (842) are de-energized.

7. The rear cycle positive device according to claim 1, characterized in that, The drive component (84) includes a solenoid valve (843); The solenoid valve (843) is connected to the high-pressure air circuit (844), the low-pressure air circuit (845) on the vehicle, and the chamber (80) between the first sliding body (82) and the second sliding body (83); In the first state, the solenoid valve (843) connects the chamber (80) to the high-pressure gas path (844), and in the second state, the solenoid valve (843) connects the chamber (80) to the low-pressure gas path (845).

8. The rear cycle positive device according to any one of claims 5-7, characterized in that, The driving component (84) further includes an elastic element (846), the two ends of which abut against the first sliding body (82) and the second sliding body (83), respectively.

9. The rear cycle positive device according to any one of claims 1-7, characterized in that, The rear wheel centering device also includes a brake (87) configured to lock the position of the tie rod (3) after the tie rod (3) has been centered.

10. The rear cycle positive device according to claim 9, characterized in that, The brake (87) is mounted on the drive shaft (22) between the rear wheel steering motor (21) and the reduction unit (23) of the rear wheel steering system.

11. The rear cycle positive device according to claim 10, characterized in that, The drive shaft (22) includes a first shaft section (221), a second shaft section (222), and a clutch (223), wherein the first shaft section (221) and the second shaft section (222) are connected by the clutch (223); The second shaft segment (222) is connected to the reduction unit (23), and the brake (87) is disposed on the second shaft segment (222).

12. The rear cycle positive device according to any one of claims 1-7, characterized in that, The driving component (84) also has a third state, wherein the driving force of the driving component (84) in the third state is greater than the driving force in the second state and less than the driving force in the first state; In the third state, the driving component (84) drives the first slider (82) and the second slider (83) to remain in the first position and the second position, respectively.

13. A rear-wheel steering system, characterized in that, The rear wheel steering system includes a rear wheel steering control unit (1), a rear wheel steering drive device (2), a tie rod (3), and a rear wheel return device (8) as described in any one of claims 1-12. The rear wheel steering drive device (2) is connected to the tie rod (3) in a transmission connection; The rear wheel steering control unit (1) is configured as follows: It is determined that the rear wheel return device (8) needs to drive the tie rod (3) to return to center; Control the drive component (84) to switch to the first state.

14. The rear-wheel steering system according to claim 13, characterized in that, The rear wheel steering control unit (1) is configured to: when it is determined that the rear wheel steering system is in a first fault state, determine that the rear wheel return device (8) needs to drive the tie rod (3) to return to center; The first fault state includes one or more of the following states: The power supply to the rear wheel steering drive unit (2) failed; The rear wheel steering motor (21) of the rear wheel steering drive device (2) is experiencing a power failure; The sensor in the rear wheel steering drive unit (2) is faulty; the sensor is used to determine the position of the tie rod (3).

15. The rear-wheel steering system according to claim 13 or 14, characterized in that, When the rear wheel return device (8) includes a brake (87), after the control of the drive unit (84) switches to the first state, the rear wheel steering control unit (1) is further configured to: Ensure that the tie rod (3) is in the alignment state; Control the brake (87) to lock the position of the tie rod (3); Control the drive component (84) to switch to the second state.

16. The rear-wheel steering system according to claim 13 or 14, characterized in that, When the drive unit (84) is in the third state, after the control of the drive unit (84) to switch to the first state, the rear wheel steering control unit (1) is further configured to: Ensure that the tie rod (3) is in the alignment state; Control the drive component (84) to switch to the third state.

17. The rear-wheel steering system according to claim 13 or 14, characterized in that, The rear wheel steering control unit (1) is also configured to: The rear wheel steering system is determined to be in a second fault state; The rear wheel steering drive device (2) is controlled to drive the tie rod (3) back to center; The second fault state includes one or more of the following states: The rear wheel steering motor (21) of the rear wheel steering drive device (2) is overheated or overloaded; The rear wheel steering control unit (1) cannot receive the rear wheel steering angle signal.

18. The rear-wheel steering system according to claim 13 or 14, characterized in that, The rear wheel steering drive device (2) includes a rear wheel steering motor (21), a drive shaft (22) and a reduction unit (23) connected in sequence, and the reduction unit (23) is connected to the tie rod (3) in a transmission connection. The drive shaft (22) includes a first shaft section (221), a second shaft section (222), and a clutch (223), wherein the first shaft section (221) and the second shaft section (222) are connected by the clutch (223); Before the control of the drive component (84) is switched to the first state, the rear wheel steering control unit (1) is also configured to control the clutch (223) to disengage.

19. A vehicle, characterized in that, The vehicle includes a rear wheel return device (8) as described in any one of claims 1-12 or a rear wheel steering system as described in any one of claims 13-18.

20. A control method for a positive rear cycle, characterized in that, The control method is applied in the rear wheel steering control unit (1) of the rear wheel steering system as described in any one of claims 13-18, and the control method includes: It is determined that the rear wheel return device (8) needs to drive the tie rod (3) to return to center; Control the drive component (84) to switch to the first state.

21. The control method according to claim 20, characterized in that, The determination that the rear wheel return-to-center device (8) needs to drive the tie rod (3) to return to center includes: When it is determined that the rear wheel steering system is in a first fault state, it is determined that the rear wheel return device (8) needs to drive the tie rod (3) to return to center. The first fault state includes one or more of the following states: The power supply to the rear wheel steering drive unit (2) failed; The rear wheel steering motor (21) of the rear wheel steering drive device (2) is experiencing a power failure; The sensor in the rear wheel steering drive unit (2) is faulty; the sensor is used to determine the position of the tie rod (3).

22. The control method according to claim 20 or 21, characterized in that, When the rear wheel return device (8) includes a brake (87), after the control method switches the drive component (84) to the first state, it further includes: Ensure that the tie rod (3) is in the alignment state; Control the brake (87) to lock the position of the tie rod (3); Control the drive component (84) to switch to the second state.

23. The control method according to claim 20 or 21, characterized in that, When the drive component (84) is in the third state, after controlling the drive component (84) to switch to the first state, the control method further includes: Ensure that the tie rod (3) is in the alignment state; Control the drive component (84) to switch to the third state.

24. The control method according to claim 20 or 21, characterized in that, When the rear wheel steering drive unit (2) includes a clutch (223), before the control method switches the drive component (84) to the first state, the control method further includes: Control the clutch (223) to disengage.

25. The control method according to claim 20 or 21, characterized in that, The control method further includes: The rear wheel steering system is determined to be in a second fault state; The rear wheel steering drive device (2) is controlled to drive the tie rod (3) back to center; The second fault state includes one or more of the following states: The rear wheel steering motor (21) of the rear wheel steering drive device (2) is overheated or overloaded; The rear wheel steering control unit (1) cannot receive the rear wheel steering angle signal.

26. A control device for a positive rear cycle, characterized in that, The control device is located in the rear wheel steering control unit (1) of the rear wheel steering system as described in any one of claims 13-18, and the control device includes: The determination module is used to determine whether the rear wheel return device (8) needs to drive the tie rod (3) to return to center. The control module is used to control the drive component (84) to switch to the first state.

27. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which is loaded and executed by the controller to implement the post-cycle positive control method as described in any one of claims 20-25.

28. A computer program product, characterized in that, The computer program product includes at least one instruction that is executed by a controller to cause the controller to implement the positive control method for the back cycle as described in any one of claims 20-25.

Images