Steer-by-wire system, control method, and vehicle

Abstract

The application discloses a kind of steer-by-wire systems, control method and vehicle, system includes: with the spindle connected with steering wheel, spindle drive gear set, torsion bar, eccentric shaft, motor and controller;Spindle drive gear set includes the first gear and second gear engaged, first gear is sleeved on the outer surface of spindle, second gear is sleeved on the outer surface of torsion bar, for when spindle rotates, drive torsion bar rotation, the upper and lower ends of torsion bar are connected with the shaft of motor by eccentric shaft, the upper end of torsion bar is also provided with first detector, the lower end of torsion bar is also provided with second detector;When spindle rotates, drive torsion bar rotation, the upper end of torsion bar exists first rotation angle, lower end exists second rotation angle, controller is also used to determine the input angle and input torque of steering wheel based on the transmission ratio of first gear and second gear, the set stiffness of torsion bar, first rotation angle and second rotation angle.The system can accurately obtain the rotation angle and torque of steering wheel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steer-by-wire, in particular to a steer-by-wire system, a control method and a vehicle. BACKGROUND

[0002] The steer-by-wire system is a new generation of steering system developed after the EPS (Electric Power Steering), and has better steering stability than the EPS. Moreover, the steer-by-wire system does not use mechanical connection between the steering wheel and the steering wheel, and completely gets rid of the inherent limitations of the traditional steering system, and the steering control and the road feel feedback of the vehicle are completely transmitted through the circuit signal. However, the steering control signal of the existing steer-by-wire system has the problems of low safety and lack of security. SUMMARY

[0003] The embodiments of the present application provide a steer-by-wire system, a control method and a vehicle, and two detectors are used for verification processing, so as to accurately obtain the steering angle and the torque of the steering wheel, provide stable input for the subsequent control chain based on the steering angle and the torque signal, and improve the safety of the vehicle.

[0004] In the first aspect, an embodiment of the present application provides the following technical scheme:

[0005] A steer-by-wire system comprises a shaft, a shaft transmission gear set, a torsion bar, an eccentric shaft, a motor and a controller. The shaft transmission gear set comprises a first gear and a second gear. The first gear is sleeved on the outer surface of the shaft and is in sliding connection with the shaft. The second gear is sleeved on the outer surface of the torsion bar. The first gear is in engagement with the second gear, and is used to drive the torsion bar to rotate when the shaft rotates. The upper and lower ends of the torsion bar are connected with the eccentric shaft, and the eccentric shaft is connected with the rotating shaft of the motor. When the torsion bar rotates, the upper and lower ends of the torsion bar have rotation angles. The upper end of the torsion bar is provided with a first detector, and the lower end of the torsion bar is provided with a second detector. The first detector and the second detector are in communication connection with the controller. The first detector is used to detect the first rotation angle of the upper end of the torsion bar and send the first rotation angle to the controller. The second detector is used to detect the second rotation angle of the lower end of the torsion bar and send the second rotation angle to the controller. The controller is used to determine the input angle and the input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle.

[0006] Preferably, the rotation angle of the second gear is greater than the rotation angle of the first gear.

[0007] Preferably, the system further comprises: an eccentric shaft clutch, a motor reduction gear set, the upper and lower ends of the torsion bar are rotationally connected with the eccentric shaft through a gear structure, the motor reduction gear set is mechanically connected with the motor, and the eccentric shaft clutch is arranged between the eccentric shaft and the motor reduction gear set; the eccentric shaft clutch is in communication connection with the controller, the motor reduction gear set is connected with the eccentric shaft through the eccentric shaft clutch when the eccentric shaft clutch is powered on, the torsion bar is rotated when the mandrel rotates, and the upper and lower ends of the torsion bar all generate a rotation angle.

[0008] Preferably, the system further comprises: a ball screw shaft clutch, a ball screw and a pulley, the pulley comprises a first transmission shaft, a second transmission shaft and a belt, and the belt is connected to the outer circumferential surfaces of the first transmission shaft and the second transmission shaft; the ball screw shaft clutch is in communication connection with the controller, the ball screw clutch is located between the motor reduction gear set and the first transmission shaft, the ball screw is located on the second transmission shaft, and the second transmission shaft and the ball screw are both sleeved on the outer surface of a raceway extending out of the lower end of the mandrel; the motor reduction gear set is connected with the pulley through the ball screw clutch when the ball screw shaft clutch is powered on, the motor is rotated to drive the motor reduction gear set and the first transmission shaft to rotate, and then the ball screw located on the second transmission shaft is driven to rotate through the belt, and the ball screw and the raceway convert the rotary motion into the axial motion of the mandrel.

[0009] Preferably, the torsion bar comprises a first sub-section and a second sub-section, the stiffness values of the first section and the lower section are equal, and the second gear is sleeved on the outer surface between the upper section and the lower section.

[0010] In a second aspect, an embodiment of the present application provides the following technical scheme:

[0011] A drive-by-wire steering control method applied to a controller in the drive-by-wire steering system in any one of the first aspect, the method comprising: receiving the first rotation angle sent by the first detector and the second rotation angle sent by the second detector; determining the input angle and input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle.

[0012] Preferably, the input angle and the input torque of the steering wheel are determined based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle, including: judging whether the first rotation angle and the second rotation angle are zero or invalid values; if neither is a zero value nor an invalid value, determining the input angle of the steering wheel based on the transmission ratio of the first gear and the second gear, the first rotation angle and the second rotation angle; determining the input torque of the steering wheel based on the set stiffness of the torsion bar, the transmission ratio, the first rotation angle and the second rotation angle.

[0013] Preferably, the input angle of the steering wheel is determined based on the transmission ratio of the first gear and the second gear, and the first rotation angle and the second rotation angle, including: judging whether the difference between the first rotation angle and the second rotation angle is greater than a preset threshold value; if the difference is greater than the preset threshold value, determining the input angle of the steering wheel by comparing the larger value of the first rotation angle and the second rotation angle with the transmission ratio.

[0014] Preferably, the input torque of the steering wheel is determined based on the set stiffness of the torsion bar, the transmission ratio, the first rotation angle and the second rotation angle, including: comparing the first rotation angle and the second rotation angle; if the first rotation angle is greater than the second rotation angle, determining the input torque of the steering wheel by comparing the product of the first rotation angle and the set stiffness of the torsion bar with the transmission ratio; if the first rotation angle is less than the second rotation angle, determining the input torque of the steering wheel by comparing the product of the second rotation angle and the set stiffness of the torsion bar with the transmission ratio.

[0015] In a third aspect, an embodiment of the present application provides the following technical solution:

[0016] A vehicle, characterized in that it comprises a vehicle body and a steer-by-wire system according to any one of the first aspect, the vehicle body comprising a steering wheel, and the shaft in the steer-by-wire system being connected to the steering wheel.

[0017] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0018] The line control steering system provided by the embodiment of the application, by sleeving the first gear on the outer surface of the mandrel and slidingly connecting the mandrel, sleeving the second gear on the outer surface of the torsion bar, and arranging the first detector and the second detector at the upper and lower ends of the torsion bar respectively, when the driver rotates the steering wheel, the mandrel rotates, drives the first gear and the second gear to rotate, and the torsion bar rotates, since the upper and lower ends of the torsion bar are connected with the motor through the eccentric shaft, no rotation is generated, thus the angle difference between the upper and lower ends of the torsion bar relative to the middle part is generated, the first detector detects the rotation angle of the upper end of the torsion bar, the second detector detects the rotation angle of the lower end of the torsion bar, and the rotation angles are transmitted to the controller, and the input angle and the input torque of the steering wheel are calculated. The two detectors are used for checking and processing in the application, the rotation angle input abnormal problem caused by the detector failure can be effectively avoided, stable input is provided for the subsequent control chain based on the rotation angle and the torque signal, the controller can output the response resistance after receiving the rotation angle and the torque signal, road feeling is simulated by the face resistance, and the driving comfort and safety of the vehicle are improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0020] Figure 1 It is a structural schematic diagram of the line control steering system in the embodiment of the application.

[0021] Figure 2 It is a structural schematic diagram of the axial sliding key groove in the embodiment of the application.

[0022] Figure 3 It is a structural schematic diagram of the first gear and the second gear in the embodiment of the application.

[0023] Figure 4 It is a structural schematic diagram of the line control steering control method in the embodiment of the application.

[0024] Figure 5 It is a structural schematic diagram of the vehicle in the embodiment of the application.

[0025] Reference signs:

[0026] Core shaft 10; core shaft drive gear set 20; torsion bar 30; torsion bar upper end gear set 40; torsion bar lower end gear set 50; first detector 60; second detector 70; eccentric shaft 80; eccentric shaft clutch 90; motor 140; first gear 201; second gear 202; raceway 101; axial sliding key groove 102; eccentric shaft upper end gear set 801; eccentric shaft lower end gear set 802; motor reduction gear set 130; screw shaft clutch 100; ball screw 110; pulley 120. DETAILED DESCRIPTION

[0027] In the online control steering system, the driving intention of the driver is not directly transmitted to the steering machine through mechanical connection, but only through signal forwarding control through the circuit and control, and the core signal is the steering wheel angle. If the steering wheel angle signal is abnormal or lost, the entire system will not work, causing the vehicle to be unable to steer or to steer unexpectedly, and other serious safety accidents. At the same time, the online control steering system is heavy, and due to the presence of the road feel simulator, it often cannot provide enough safe collapse distance for the driver, and will cause certain harm to the driver during the collision.

[0028] Therefore, the embodiments of the present application provide an online control steering system, a control method and a vehicle, and two detectors are used for verification processing, so as to accurately obtain the steering angle and torque of the steering wheel, provide stable input for the subsequent control chain based on the steering angle and torque signal, and improve the safety of the vehicle.

[0029] The technical scheme of the embodiments of the present application is to solve the above technical problems, and the general idea is as follows:

[0030] An online control steering system, comprising: a core shaft connected with a steering wheel, a core shaft drive gear set, a torsion bar, an eccentric shaft, a motor and a controller; the core shaft drive gear set comprises a first gear and a second gear, the first gear is sleeved on the outer surface of the core shaft and is in sliding connection with the core shaft, the second gear is sleeved on the outer surface of the torsion bar, the first gear is in engagement with the second gear, and the first gear is used to drive the torsion bar to rotate when the core shaft rotates, the upper and lower ends of the torsion bar are connected with the eccentric shaft, and the eccentric shaft is connected with the rotating shaft of the motor; when the torsion bar rotates, the upper and lower ends of the torsion bar both have a rotation angle, the upper end of the torsion bar is further provided with a first detector, the lower end of the torsion bar is further provided with a second detector, the first detector is used to detect the first rotation angle of the upper end of the torsion bar and send the first rotation angle to the controller, the second detector is used to detect the second rotation angle of the lower end of the torsion bar and send the second rotation angle to the controller, and the controller is used to determine the input angle and input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle.

[0031] In order to better understand the above technical scheme, the above technical scheme will be described in detail in combination with the drawings of the specification and the specific embodiments.

[0032] In a first aspect, the embodiments of the present application provide a steer-by-wire system, in particular as shown in the accompanying drawings, the system comprises a spindle 10 connected with a steering wheel, a spindle transmission gear set 20, a torsion bar 30, an eccentric shaft 80, a motor 140 and a controller. Figure 1

[0033] As shown in the accompanying drawings, the spindle transmission gear set 20 comprises a first gear 201 and a second gear 202, the first gear 201 is sleeved on the outer surface of the spindle 10 and is in sliding connection with the spindle 10, the second gear 202 is sleeved on the outer surface of the torsion bar 30, the first gear 201 is engaged with the second gear 202, and the first gear 201 is used to drive the torsion bar 30 to rotate when the spindle 10 rotates, the upper and lower ends of the torsion bar 30 are connected with the eccentric shaft 80, and the eccentric shaft 80 is connected with the motor 140. Figure 2 When the spindle 10 rotates to drive the torsion bar 30 to rotate, the upper and lower ends of the torsion bar 30 both have a rotation angle, the upper end of the torsion bar 30 is further provided with a first detector 60, the lower end of the torsion bar 30 is further provided with a second detector 70, the first detector 60 and the second detector 70 are both in communication connection with the controller, the first detector 60 is used to detect a first rotation angle of the upper end of the torsion bar 30 and send the first rotation angle to the controller, and the second detector 70 is used to detect a second rotation angle of the lower end of the torsion bar 30 and send the second rotation angle to the controller, and the controller is used to determine an input angle and an input torque of the steering wheel based on a transmission ratio of the first gear 201 and the second gear 202, a set stiffness of the torsion bar 30, the first rotation angle and the second rotation angle.

[0034] Optionally, the first detector 60 and the second detector 70 are both torque rotation angle sensors. The upper end of the torsion bar 30 can be the top of the torsion bar 30, and the lower end of the torsion bar 30 can be the bottom of the torsion bar 30.

[0035] In the embodiment, the torsion bar 30 can comprise an upper segment and a lower segment, the stiffness values of the upper segment and the lower segment are equal, and the second gear 202 is sleeved on the outer surface between the upper segment and the lower segment.

[0036] It should be noted that the second gear 202 is generally arranged at the middle position of the torsion bar 30, and due to various reasons such as machining errors, the stiffness curve of the torsion bar 30 has certain fluctuations, thereby causing the torque output to fluctuate. In order to improve the accuracy of the torque output, the diameters and lengths of the upper and lower segments of the torsion bar 30 are adjusted so that the stiffness values of the upper and lower segments are uniform, and are both k. In this way, even if the diameters and lengths of the upper and lower segments of the torsion bar 30 are not uniform, the stiffness values are equal, so that the machining of the size of the torsion bar 30 reduces the torque output fluctuation caused by the fluctuation of the stiffness curve.

[0037]

[0038] ​​The two-stage torsion bars 30 of different sizes can effectively eliminate mechanical errors, further improve the data accuracy, and reduce the fluctuation range of the output data, thereby providing stable input for the subsequent control chain based on the rotation angle and torque signals. The stiffness values of the upper and lower two stages can be set.

[0039] In specific embodiments, as shown in Figure 1 The system can further include an eccentric shaft clutch 90, a motor reduction gear set 130, the upper and lower ends of the torsion bar 30 being rotationally connected to the eccentric shaft 80 through a gear structure, the motor reduction gear set 130 being mechanically connected to the motor 140, and the eccentric shaft clutch 90 being arranged between the eccentric shaft 80 and the motor reduction gear set 130.

[0040] The eccentric shaft clutch 90 is in communication with the controller. When the eccentric shaft clutch 90 is powered, the motor reduction gear set 130 is connected to the eccentric shaft 80 through the eccentric shaft clutch 90. When the mandrel 10 rotates, the torsion bar 30 rotates, and the upper and lower ends of the torsion bar 30 both produce a rotation angle.

[0041] In one embodiment, as shown in Figure 1 The upper and lower ends of the torsion bar 30 are rotationally connected to the eccentric shaft 80 through a gear structure, which can include that the upper end of the torsion bar 30 is provided with a torsion bar upper end gear set 40, the lower end is provided with a torsion bar lower end gear set 50, the upper end of the eccentric shaft 80 is provided with an eccentric shaft upper end gear set 801, and the lower end is provided with an eccentric shaft lower end gear set 802. The torsion bar upper end gear set 40 is engaged with the eccentric shaft upper end gear set 801, and the torsion bar lower end gear set 50 is engaged with the eccentric shaft lower end gear set 802.

[0042] Specifically, when the controller receives a steering signal, the controller controls the eccentric shaft clutch 90 to be powered, and the eccentric shaft clutch 90 is attracted to fixedly connect the eccentric shaft 80 and the motor reduction gear set 130. When the driver rotates the steering wheel, the mandrel 10 rotates, the mandrel 10 rotates synchronously with the first gear 201 in the mandrel transmission gear set 20, thereby driving the second gear 202 in the mandrel transmission gear set 20 to rotate.

[0043] Further, the rotation angle of the second gear 202 is greater than that of the first gear 201, so that the input rotation angle can be amplified, thereby improving the response speed and measurement accuracy of the torque rotation sensor. For example, the transmission ratio of the mandrel transmission gear set 20 is i1(i1>1).

[0044] After the second gear 202 rotates, the upper and lower ends of the torsion bar 30 are connected to the motor 140 through the eccentric shaft 80, and the upper and lower ends do not rotate relative to the middle part, so that a first rotation angle of the upper end of the torsion bar 30 relative to the middle part and a second rotation angle of the lower end of the torsion bar 30 relative to the middle part are generated. The first torque rotation angle sensor detects the first rotation angle θ1 of the upper end of the torsion bar 30, and the second torque sensor detects the second rotation angle θ2 of the lower end of the torsion bar 30, and transmits the values to the controller. The controller calculates the input angle A of the steering wheel and the input torque T based on the set stiffness, the transmission ratio, the first rotation angle θ1 and the second rotation angle θ2.

[0045] In the embodiment, as shown in Figure 1 The system can further include a lead screw shaft clutch 100, a ball screw 110, and a belt pulley 120. The belt pulley 120 includes a first transmission shaft, a second transmission shaft, and a belt connected to the outer circumferential surfaces of the first transmission shaft and the second transmission shaft. The lead screw shaft clutch 100 is in communication with the controller. The ball screw 110 clutch is located between the motor reduction gear set 130 and the first transmission shaft. The ball screw 110 is located on the second transmission shaft. The raceway 101 extending from the lower end of the mandrel 10 penetrates the second transmission shaft and the ball screw 110, so that the second transmission shaft and the ball screw 110 are both sleeved on the outer surface of the raceway 101 extending from the lower end of the mandrel 10.

[0046] When the lead screw shaft clutch 100 is powered on, the motor reduction gear set 130 and the belt pulley 120 are connected by the ball screw 110 clutch. The motor 140 rotates to drive the motor reduction gear set 130 and the first transmission shaft to rotate, and then drives the ball screw 110 located on the second transmission shaft to rotate through the belt. The ball screw 110 and the raceway 101 convert the rotary motion into the axial motion of the mandrel 10.

[0047] The ball in the ball screw 110 is in sliding connection with the raceway 101. When the ball screw 110 rotates, the ball slides on the raceway 101 to drive the raceway 101 to move axially, and then converts the rotary motion into the axial motion of the mandrel 10.

[0048] In specific embodiments, if an axial adjustment signal or an active collapse signal is received, the lead screw shaft clutch 100 is powered on, and the motor reduction gear set 130 and the belt pulley 120 are connected by the ball screw 110 clutch. The motor 140 is controlled to operate, so that the motor 140 rotates to drive the motor reduction gear set 130 and the first transmission shaft to rotate, and then drives the ball screw 110 located on the second transmission shaft to rotate through the belt. The raceway 101 is controlled to rotate, so that the mandrel 10 moves axially. In the axial adjustment mode, there is no obstacle at the lower end of the mandrel 10 and other components, and the axial motion of the mandrel 10 can be maximized.

[0049] Further, in order to avoid the core shaft 10 from rotating when it moves axially, as shown in Figure 3 The core shaft 10 is also provided with an axial sliding key groove 102, and the first gear 201 axially slides on the core shaft 10 through the axial sliding key groove 102.

[0050] When the steering system enters the active collapse mode, the working mode is the same as the axial adjustment mode, and the difference is that in the active collapse mode, the core shaft 10 only moves downward, driving the steering wheel away from the driver, thereby reducing the injury to the driver in the collision, and the original state can also be restored after the collision, reducing the maintenance cost caused by the failure.

[0051] It should be noted that the axial adjustment signal can be initiated by the user to adjust the length of the steering wheel axis to meet the needs of drivers of different sizes for the distance between the steering wheel and themselves, and the active collapse signal is sent when the vehicle is in a collision.

[0052] In the embodiment, the controller receives the first rotation angle sent by the first detector 60 and the second rotation angle sent by the second detector 70, and determines the input angle and the input torque of the steering wheel based on the transmission ratio of the first gear 201 and the second gear 202, the set stiffness of the torsion bar 30, the first rotation angle and the second rotation angle.

[0053] Determining the input angle and the input torque of the steering wheel based on the transmission ratio of the first gear 201 and the second gear 202, the set stiffness of the torsion bar 30, the first rotation angle and the second rotation angle can include: judging whether the first rotation angle and the second rotation angle are zero values or invalid values; if neither is a zero value nor an invalid value, determining the input angle of the steering wheel based on the transmission ratio of the first gear 201 and the second gear 202, the first rotation angle and the second rotation angle; determining the input torque of the steering wheel based on the set stiffness of the torsion bar 30, the transmission ratio, the first rotation angle and the second rotation angle.

[0054] For example, the invalid value can be a value exceeding the detection range of the sensor.

[0055] Specifically, determining the input angle of the steering wheel based on the transmission ratio of the first gear 201 and the second gear 202, the first rotation angle and the second rotation angle can include: judging whether the difference between the first rotation angle and the second rotation angle is greater than a preset threshold; if the difference is greater than the preset threshold, determining the input angle of the steering wheel by dividing the larger value of the first rotation angle and the second rotation angle by the transmission ratio.

[0056] The determining the input torque of the steering wheel based on the set stiffness, the transmission ratio, the first rotation angle and the second rotation angle of the torsion bar 30 can comprise: comparing the first rotation angle with the second rotation angle; if the first rotation angle is greater than the second rotation angle, determining the input torque of the steering wheel by dividing the product of the first rotation angle and the set stiffness of the torsion bar 30 by the transmission ratio; and if the first rotation angle is less than the second rotation angle, determining the input torque of the steering wheel by dividing the product of the second rotation angle and the set stiffness of the torsion bar 30 by the transmission ratio.

[0057] Specifically, if the difference between θ1 and θ2 is greater than a preset threshold (e.g., > 20%), it is considered that the system is abnormal, an alarm is prompted, and the controller calculates the driver input angle A = (the larger value of θ1 and θ2) / i1 and synchronously calculates the torque driver input torque T. If θ1 is greater, T = θ1 * k / i1; and if θ2 is greater, T = θ2 * k / i1.

[0058] If the difference between the first rotation angle and the second rotation angle is less than or equal to a preset threshold, the sum of the first rotation angle and the second rotation angle is divided by the product of the transmission ratio and 2 to determine the input angle of the steering wheel. Then, the determining the input torque of the steering wheel based on the set stiffness, the transmission ratio, the first rotation angle and the second rotation angle of the torsion bar 30 can comprise: adding the product of the first rotation angle and the set stiffness to the product of the second rotation angle and the set stiffness, and then dividing the result by the transmission ratio to determine the input torque of the steering wheel.

[0059] Specifically, if the difference between θ1 and θ2 is less than or equal to a preset threshold (e.g., ≤ 20%), it is considered that the system is working normally, the controller calculates the driver input angle A = (θ1 + θ2) / (2 * i1) and calculates the torque driver input torque T = (θ1 * k + θ2 * k) / i1. (The angle here is not superimposed, so it needs to be divided by 2. The torque force is superimposed, so it does not need to be divided by 2.)

[0060] If the first rotation angle θ1 and the second rotation angle θ2 are both zero or invalid values, it indicates that the input is lost, which represents that there may be a serious hardware failure, an alarm is prompted, and the vehicle enters a deceleration mode until it stops.

[0061] If one of the first rotation angle θ1 and the second rotation angle θ2 is a zero or invalid value, the input angle of the steering wheel is determined based on the transmission ratio of the first gear 201 and the second gear 202, the first rotation angle and the second rotation angle; and the input torque of the steering wheel is determined based on the set stiffness of the torsion bar 30 and the input angle.

[0062] Specifically, if one of θ1 and θ2 is 0 or invalid, it is determined that a more serious fault anomaly exists in the system, an alarm is given, and the vehicle speed is limited. At the same time, the controller calculates the driver input angle A = (the valid non-0 value of θ1 and θ2) / i1, and calculates the torque driver input torque T = A * K. In this way, the vehicle can still be controlled by one of the angle signals, and the road feedback is shielded, and the driver is physically fed back that the vehicle is abnormal.

[0063] Finally, the controller outputs the input angle and input torque. Since the torsion bar 30 has a function of resisting deformation, when the torsion bar 30 is deformed, the upper end gear set 40 of the torsion bar and the lower end gear set 50 of the torsion bar drive the eccentric shaft 80 to rotate, and the eccentric shaft 80 has been connected with the motor reduction gear set 130 through the eccentric shaft clutch 90, that is, connected with the motor 140 output, and the controller outputs a response resistance after receiving the angle A and torque T signals, that is, the road feeling of the surface resistance is simulated.

[0064] Thus, the steering system can include: a mandrel 10, a mandrel transmission gear set 20, a torsion bar 30, a torsion bar upper end gear set 40, a torsion bar lower end gear set 50, a torsion bar 30 upper end torque angle sensor, a torsion bar 30 lower end torque angle sensor, an eccentric shaft 80, an eccentric shaft clutch 90, a ball screw shaft clutch 100, a ball screw 110, a belt pulley 120, a motor reduction gear set 130, a motor 140, a controller, and a housing (the housing is a basic support structure, not shown), wherein the mandrel 10 is connected with the steering wheel for receiving the driver's operation intention.

[0065] Among them, the torsion bar 30 upper end torque angle sensor, the torsion bar 30 lower end torque angle sensor, the eccentric shaft clutch 90, the ball screw shaft clutch 100 and the controller are connected through a wire harness. The controller receives the whole vehicle input request, selects the axial adjustment mode, the active collapse mode or the normal steering mode:

[0066] If the axial adjustment mode is entered, the controller controls the ball screw 110 clutch to be attracted, and the motor reduction gear set 130 and the belt pulley 120 are connected, and then the motor 140 rotates to drive the motor reduction gear set 130 and the belt pulley 120 to rotate, and then the belt drives the ball screw 110 to rotate, and the ball screw 110 and the raceway 101 at the lower end of the mandrel 10 convert the rotary motion into the axial motion of the mandrel 10, realizing the axial adjustment function of the mandrel 10.

[0067] If the active collapse mode is entered, the controller controls the ball screw 110 clutch to be attracted, and the motor reduction gear set 130 and the belt pulley 120 are connected, and then the motor 140 rotates to drive the motor reduction gear set 130 and the belt pulley 120 to rotate, and then the belt drives the ball screw 110 to rotate, and the ball screw 110 and the raceway 101 at the lower end of the mandrel 10 convert the rotary motion into the axial motion of the mandrel 10, realizing the axial adjustment function of the mandrel 10.

[0068] If entering the normal steering mode, the controller controls the eccentric shaft clutch 90 to be attracted, and the eccentric shaft 80 is fixedly connected with the motor reduction gear set 130. When the driver rotates the steering wheel, the mandrel 10 is rotated, the mandrel 10 is synchronously rotated with the first gear 201, and the second gear 202 is rotated. The upper and lower ends of the torsion bar 30 are not rotated because the upper and lower ends of the torsion bar 30 are connected with the motor 140 through the eccentric shaft 80. Thus, the angle difference between the upper and lower ends of the torsion bar 30 and the middle part is generated. The upper and lower sensors detect the rotation angle θ1 and θ2 values of the upper and lower ends of the torsion bar 30 respectively, and the values are transmitted to the controller to calculate the input angle A of the driver. After the controller receives θ1 and θ2, the input torque T of the driver is calculated in combination with the preset k parameter and the transmission ratio.

[0069] By providing a column structure that is compact, has a long collapse distance and a rotation angle redundancy function, for use in a steer-by-wire system, the steer-by-wire system proposed in the application can effectively avoid abnormal rotation angle input caused by detector failure, and the use of two detectors for verification processing and two sections of different size torsion bars 30 eliminates mechanical errors, further improves data accuracy, and reduces the fluctuation range of output data, providing stable input for subsequent control chains based on rotation angle and torque signals.

[0070] In summary, the steer-by-wire system provided by the embodiments of the application simultaneously uses two detectors for verification processing to accurately obtain the rotation angle and torque of the steering wheel, provides stable input for subsequent control chains based on rotation angle and torque signals, and improves vehicle safety.

[0071] In a second aspect, based on the same inventive concept, the embodiments of the application provide a steer-by-wire control method applied to the controller of the steer-by-wire system of any one of the preceding first aspect. Specifically, as shown in Figure 4 The method comprises the following steps S101 to S102:

[0072] Step S101, receiving the first rotation angle sent by the first detector and the second rotation angle sent by the second detector;

[0073] Step S102, determining the input angle and input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle.

[0074] As an optional embodiment, the input angle and input torque of the steering wheel are determined based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle, including: judging whether the first rotation angle and the second rotation angle are zero values ​​or invalid values; if neither is zero value nor invalid value, determining the input angle of the steering wheel based on the transmission ratio of the first gear and the second gear, the first rotation angle and the second rotation angle; determining the input torque of the steering wheel based on the set stiffness of the torsion bar, the transmission ratio, the first rotation angle and the second rotation angle.

[0075] As an optional embodiment, the input angle of the steering wheel is determined based on the transmission ratio of the first gear and the second gear, the first rotation angle and the second rotation angle, including: judging whether the difference between the first rotation angle and the second rotation angle is greater than a preset threshold; if the difference is greater than the preset threshold, comparing the larger value of the first rotation angle and the second rotation angle with the transmission ratio to determine the input angle of the steering wheel.

[0076] As an optional embodiment, the input torque of the steering wheel is determined based on the set stiffness of the torsion bar, the transmission ratio, the first rotation angle and the second rotation angle, including: comparing the first rotation angle and the second rotation angle; if the first rotation angle is greater than the second rotation angle, multiplying the product of the first rotation angle and the set stiffness of the torsion bar by the transmission ratio to determine the input torque of the steering wheel; if the first rotation angle is less than the second rotation angle, multiplying the product of the second rotation angle and the set stiffness of the torsion bar by the transmission ratio to determine the input torque of the steering wheel.

[0077] An embodiment of the present invention provides a wire-controlled steering control method, the implementation principle and technical effects of which are the same as those of the aforementioned system embodiment. For the sake of brief description, for matters not mentioned in the method embodiment, reference may be made to the corresponding contents in the aforementioned system embodiment.

[0078] In a fourth aspect, based on the same inventive concept, this embodiment provides a vehicle 500, such as Figure 5 As shown, it includes a vehicle body 501 and a steer-by-wire system 502 as described in the first aspect above, which is installed in the vehicle body.

[0079] The vehicle body 501 includes a steering wheel. The core shaft in the wire-controlled steering system 502 is connected to the steering wheel. The wire-controlled steering system is used to respond to the control of the steering wheel and perform axial control on the steering wheel through the core shaft.

[0080] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0081] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0082] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A module that specifies functions in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction module, which is implemented in the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0085] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that the appended claims include all such modifications and variations as fall within the scope of the present application.

[0086] It is apparent that those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. Thus, it is intended that the application include all such modifications and alterations insofar as they come within the scope of the claims or the equivalents thereof.

Claims

1. A steer-by-wire system, characterized in that: include: A spindle connected to the steering wheel, a spindle transmission gear set, a torsion bar, an eccentric shaft, a motor, and a controller; The spindle transmission gear set includes a first gear and a second gear, the first gear is sleeved on the outer surface of the spindle and is slidably connected to the spindle, the second gear is sleeved on the outer surface of the torsion bar, the first gear and the second gear are meshed with each other, and are used to drive the torsion bar to rotate when the spindle rotates, the upper and lower ends of the torsion bar are connected to the eccentric shaft, and the eccentric shaft is connected to the rotating shaft of the motor; When the torsion bar rotates, there are rotation angles at both the upper and lower ends of the torsion bar. A first detector is also provided at the upper end of the torsion bar, and a second detector is also provided at the lower end of the torsion bar. The first detector and the second detector are both communicatively connected to the controller. The first detector is used to detect the first rotation angle of the upper end of the torsion bar and send it to the controller, and the second detector is used to detect the second rotation angle of the lower end of the torsion bar and send it to the controller. The controller is used to determine the input angle and input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle and the second rotation angle.

2. The system according to claim 1, wherein A rotation angle of the second gear is greater than a rotation angle of the first gear.

3. The system according to claim 1, wherein: Also includes: An eccentric shaft clutch and a motor reduction gear set, wherein the upper and lower ends of the torsion bar are rotationally connected to the eccentric shaft through a gear structure, the motor reduction gear set is mechanically connected to the motor, and the eccentric shaft clutch is arranged between the eccentric shaft and the motor reduction gear set; The eccentric shaft clutch is in communication with the controller. When the eccentric shaft clutch is energized, the motor reduction gear set and the eccentric shaft are connected by suction through the eccentric shaft clutch, and the torsion bar is driven to rotate when the core shaft rotates.

4. The system according to claim 3, wherein: Also includes: A screw shaft clutch, a ball screw and a pulley, wherein the pulley includes a first transmission shaft, a second transmission shaft and a belt, and the belt is connected to the outer circumference of the first transmission shaft and the second transmission shaft; The screw shaft clutch is in communication with the controller, the ball screw clutch is located between the motor reduction gear set and the first transmission shaft, the ball screw is located on the second transmission shaft, and the second transmission shaft and the ball screw are both sleeved on the outer surface of the raceway extending from the lower end of the core shaft; When the screw shaft clutch is energized, the motor reduction gear set and the pulley are connected by attraction through the ball screw clutch. The rotation of the motor drives the motor reduction gear set and the first transmission shaft to rotate, and then drives the ball screw on the second transmission shaft to rotate through the belt. The ball screw and the raceway convert the rotational motion into axial motion of the core shaft.

5. The system according to claim 1, wherein: The torsion bar includes an upper section and a lower section, the upper section and the lower section have the same stiffness value, and the second gear is sleeved on the outer surface between the upper section and the lower section.

6. A steer-by-wire control method, characterized in that: A controller used in a steer-by-wire system according to any one of claims 1 to 5, wherein the method comprises: receiving a first rotation angle sent by the first detector and a second rotation angle sent by the second detector; An input angle and an input torque of a steering wheel are determined based on a transmission ratio between the first gear and the second gear, a set stiffness of the torsion bar, the first rotation angle, and the second rotation angle.

7. The method according to claim 6, wherein The determining of the input angle and input torque of the steering wheel based on the transmission ratio of the first gear and the second gear, the set stiffness of the torsion bar, the first rotation angle, and the second rotation angle includes: determining whether the first rotation angle and the second rotation angle are zero or invalid values; If neither of them is a zero value nor an invalid value, determining an input angle of the steering wheel based on the transmission ratio of the first gear and the second gear, the first rotation angle, and the second rotation angle; An input torque of a steering wheel is determined based on a set stiffness of a torsion bar, the transmission ratio, the first rotation angle, and the second rotation angle.

8. The method according to claim 7, wherein The determining the input angle of the steering wheel based on the transmission ratio of the first gear and the second gear, the first rotation angle, and the second rotation angle includes: Determining whether a difference between the first rotation angle and the second rotation angle is greater than a preset threshold; If the difference is greater than a preset threshold, the larger value of the first rotation angle and the second rotation angle is compared with the transmission ratio to determine the input angle of the steering wheel.

9. The method according to claim 8, wherein The determining of the input torque of the steering wheel based on the set stiffness of the torsion bar, the transmission ratio, the first rotation angle, and the second rotation angle includes: comparing the first rotation angle with the second rotation angle; If the first rotation angle is greater than the second rotation angle, multiplying the product of the first rotation angle and the set stiffness of the torsion bar by the transmission ratio to determine the input torque of the steering wheel; If the first rotation angle is smaller than the second rotation angle, the product of the second rotation angle and the set stiffness of the torsion bar is divided by the transmission ratio to determine the input torque of the steering wheel.

10. A vehicle, characterized in that: include: A vehicle body and a steer-by-wire system according to any one of claims 1 to 5, wherein the vehicle body comprises a steering wheel, and the core shaft in the steer-by-wire system is connected to the steering wheel.

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