Plunger type drive-by-wire hand feeling simulator and control method

Abstract

The embodiment of the invention discloses a plunger type drive-by-wire hand feeling simulator and a control mode. The hand feeling simulator comprises a plunger assembly and a plunger barrel assembly. The plunger assembly comprises an input shaft, a torsion bar, a screw rod and a first plunger; the input shaft is of a hollow structure, and a TAS sensor stator is arranged on the input shaft. One end of the torsion bar penetrates through the input shaft and is fixedly connected with the input shaft, and the other end is pressed in an inner ring hole of the screw in an interference manner; the screw is in threaded connection with the first plunger, and a TAS sensor rotor is arranged on the screw; the plunger barrel assembly comprises a plunger barrel, a second plunger and a coil assembly; a first plunger and a second plunger are arranged in the plunger barrel, magnetorheological fluid materials are injected into the plunger barrel, and the first plunger is fixedly connected with the second plunger; a first spring is arranged at one end of the second plunger, and a second spring is arranged at the other end. The use of a motor and a speed reducing mechanism is avoided, the stability of hand feeling simulation is improved, fluctuation is reduced, noise is lowered, the peripheral arrangement of the vehicle does not need to be adjusted, and integration and upgrading are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile wire-controlled steering systems, and in particular to a plunger-type wire-controlled feel simulator and a control method thereof. Background Art

[0002] With the continuous development of automobile steering systems, the wire-controlled steering system has shown a new development direction for the steering industry. The current market is entering the initial promotion stage of wire-controlled steering, but most of the current mainstream solutions use speed reduction mechanisms such as worm gears, synchronous pulleys, planetary gear systems, etc. with motors to achieve the needs of hand feel simulation, and such solutions have the following disadvantages:

[0003] 1. The structural size is too large. Usually, the steering gear installation part on the car is mostly arranged around the traditional column design. The scheme of the reduction mechanism equipped with a motor is usually impossible to arrange, and the vehicle manufacturer is forced to adjust the surrounding area;

[0004] 2. The structure is complex, involving many parts, and the procurement cost of the motor and reduction mechanism is difficult to reduce, resulting in high manufacturing costs;

[0005] 3. Due to the involvement of the deceleration mechanism, the hand feel simulator loses nearly 20% of its mechanical efficiency. At the same time, the hand feel fluctuates significantly, the hand feel is poor, and it is easy to generate noise;

[0006] 4. The control is complex and it is difficult to develop and verify. Summary of the invention

[0007] In order to solve the above technical problems, the present application provides a plunger-type wire-controlled feel simulator and control method, which aims to improve the feel simulation performance of the wire-controlled steering system. Through optimized design, the mechanical efficiency of the wire-controlled steering feel simulation is enhanced, the fluctuation of the simulated feel is effectively reduced, the noise generated during operation is reduced, and the driving comfort is improved. At the same time, the feel simulator has a simple structure and a small size. It does not require adjustments to the surrounding layout of the vehicle, which is convenient for integration and upgrading. The present application utilizes the characteristics of magnetorheological fluid materials to avoid the use of motors and reduction mechanisms, reducing manufacturing costs. The damping force of the feel is accurately controlled by adjusting the magnitude of the current. The control method is simple and intuitive, reducing the difficulty of development and verification. The technical solutions provided by the present application are as follows:

[0008] On the one hand, the present application provides a plunger-type wire-controlled feel simulator, comprising a plunger assembly and a plunger barrel assembly;

[0009] The plunger assembly includes an input shaft, a torsion bar, a screw rod and a first plunger;

[0010] The input shaft is a hollow structure, on which a TAS sensor stator is arranged;

[0011] One end of the torsion bar passes through the input shaft and is fixedly connected thereto, and the other end is press-fitted into the inner circle hole of the screw rod;

[0012] The screw is threadedly connected to the first plunger, and a TAS sensor rotor is arranged on the screw;

[0013] The plunger barrel assembly comprises a plunger barrel, a second plunger and a coil assembly;

[0014] The first plunger and the second plunger are arranged in the plunger barrel, into which magnetorheological fluid material is injected, the coil assembly is sleeved on the outside of the plunger barrel, and the first plunger and the second plunger are fixedly connected;

[0015] The second plunger is provided with a first spring at one end close to the first plunger, and a second spring at the other end.

[0016] In some specific embodiments, a plurality of sliders are provided on the outer circumferential surface of the first plunger, a plurality of slide grooves matching with the sliders are provided on the inner circumferential surface of the plunger barrel, and the first plunger slides along the plunger barrel, thereby pushing the magnetorheological fluid material to move.

[0017] In some specific embodiments, the plunger assembly further includes a sliding bearing and a first sealing ring;

[0018] The sliding bearing is press-fitted on one end of the inner ring hole close to the input shaft;

[0019] The first sealing ring is installed on one end of the first plunger close to the second plunger.

[0020] In some specific embodiments, the plunger barrel assembly further includes a second sealing ring and a third sealing ring, wherein the second sealing ring is disposed at an end of the plunger barrel away from the first plunger;

[0021] The third sealing ring is installed on an end of the second plunger close to the first plunger.

[0022] In some specific embodiments, the hand feel simulator further includes a PCBA board, which is fixed on the housing and has a TAS communication interface and a power supply and CAN signal communication interface integrated on the PCBA board;

[0023] The TAS communication interface is fixedly connected to the TAS sensor stator interface;

[0024] The hand feel simulator is connected to the vehicle power supply, vehicle CAN signal and steering actuator CAN signal interface respectively through the power supply and CAN signal communication interface.

[0025] In some specific implementations, the coil assembly includes a power PIN angle, and the power PIN angle is electrically connected to the PCBA board.

[0026] In some specific implementations, the hand feel simulator further includes a shell, a limit cover and an end cover, and the limit cover and the end cover are arranged at both ends of the shell;

[0027] The input shaft passes through the end cover and is fixedly connected thereto;

[0028] One end of the second spring facing away from the second plunger is fixed to the limiting cover.

[0029] In some specific implementations, a cover is provided on the PCBA board, and the cover is matched and fixedly connected with the housing.

[0030] In some specific embodiments, a liquid injection port is provided on the plunger barrel, and a sealing plug is provided on the liquid injection port.

[0031] On the other hand, the present application also provides a control method for a plunger-type wire-controlled feel simulator, comprising:

[0032] Obtaining torque angle information, wherein the torque angle information is collected by a TAS sensor stator and a TAS sensor rotor;

[0033] Obtain vehicle speed information and steering actuator status information;

[0034] Based on the torque angle information, the vehicle speed information and the steering actuator state information, a required hand-feel damping force is obtained;

[0035] Based on the desired hand-feel damping force, the current in the coil assembly is adjusted.

[0036] By adopting the above technical solution, the plunger-type wire-controlled feel simulator and control method provided by the present application have the following beneficial effects:

[0037] 1. The plunger-type wire-control feel simulator provided by the present application has a simple structure and a small size, does not require adjustment of the surrounding layout of the vehicle, and is easy to integrate and upgrade;

[0038] 2. This application utilizes the characteristics of magnetorheological fluid materials to avoid the use of motors and reduction mechanisms, reducing manufacturing costs. At the same time, it avoids the impact of fluctuations in motors and reduction mechanisms, making the hand feel smoother, reducing noise generated during operation, and improving driving comfort;

[0039] 3. The plunger-type wire-controlled feel simulator of the present application has a simplified structural design, which significantly reduces the loss of mechanical efficiency compared to the traditional feel simulator using a motor and a reduction mechanism;

[0040] 4. This application accurately controls the hand-feel damping force by adjusting the magnitude of the current. The control method is simple and intuitive, which reduces the difficulty of development and verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A schematic diagram of a hand feel simulator provided in an embodiment of the present application;

[0043] Figure 2 An exploded diagram of a hand feel simulator provided in an embodiment of the present application;

[0044] Figure 3 A cross-sectional view of a hand feel simulator provided in an embodiment of the present application;

[0045] Figure 4 A schematic diagram of a first plunger and a plunger barrel provided in an embodiment of the present application;

[0046] Figure 5 Principle process of the hand feel simulator provided in the embodiment of the present application Figure 1 ;

[0047] Figure 6 Principle process of the hand feel simulator provided in the embodiment of the present application Figure 2 .

[0048] The following is a supplementary description of the attached drawings:

[0049] 101-input shaft; 102-torsion bar; 103-screw; 104-first plunger; 105-TAS sensor stator; 106-TAS sensor rotor; 107-sliding bearing; 108-first sealing ring;

[0050] 201- plunger barrel; 202- second plunger; 203- coil assembly; 2031- power PIN angle; 204- first spring; 205- second spring; 206- second sealing ring; 207- third sealing ring; 208- sealing plug;

[0051] 301-housing; 302-limiting cover; 303-end cover; 304-PCBA board; 3041-TAS communication interface; 3042-power supply and CAN signal communication interface; 305-cover. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0054] When a numerical range is disclosed herein, the above range is deemed to be continuous and includes the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all sub-ranges included therein. For example, a specified range from "1 to 10" should be deemed to include any and all sub-ranges between a minimum of 1 and a maximum of 10. Exemplary sub-ranges of ranges 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0055] See also Figure 1 and Figure 2 The plunger-type wire-controlled feel simulator provided in the embodiment of the present application includes a plunger assembly and a plunger barrel assembly; the plunger assembly is used to convert the force input by the steering wheel into the output force, and the plunger barrel assembly provides a movement path and space for the plunger assembly. Through the coordinated work of the plunger assembly and the plunger barrel assembly, the plunger-type wire-controlled feel simulator achieves precise force feedback and control.

[0056] The plunger assembly includes an input shaft 101 , a torsion bar 102 , a screw rod 103 and a first plunger 104 .

[0057] The input shaft 101 is a hollow structure, on which a TAS sensor stator 105 is disposed; specifically, the input shaft 101 is connected to the steering wheel of the car to provide the driver with a hand-feel simulated torque; the TAS sensor stator 105 is fixed to one end of the input shaft 101 close to the screw 103 by laser welding.

[0058] One end of the torsion bar 102 passes through the input shaft 101 and is fixedly connected thereto, and the other end is interference fit in the inner circle hole of the screw 103; specifically, the torsion bar 102 and the input shaft 101 are provided with corresponding mounting holes at the end close to the steering wheel, and the torsion bar 102 passes through the input shaft 101 and is fixed to the input shaft 101 by fasteners, and the fasteners include cylindrical pins, bolts and screws, etc.; one end of the torsion bar 102 is splined, and the other end is a cylinder, and the screw 103 is provided with an inner circle hole, and the spline end of the torsion bar 102 is interference fit in the inner circle hole of the screw 103. By interference fit, the spline end of the torsion bar 102 is pressed into the inner circle hole of the screw 103, ensuring a close fit between the two components, reducing relative rotation and sliding, while being able to transmit a larger torque, and providing a stable feel and feedback.

[0059] The screw 103 is threadedly connected to the first plunger 104, on which a TAS sensor rotor 106 is arranged; specifically, an internal thread is arranged in the inner hole of the first plunger 104, which is screwed with the external thread of the screw 103; the TAS sensor rotor 106 is fixed to the end of the screw 103 near one end of the torsion bar 102 by laser welding; the TAS sensor stator 105 and the TAS sensor rotor 106 measure the torque and angle changes of the input shaft 101. The TAS sensor usually includes a fixed coil and a rotatable magnetic sensitive element. When torque is applied, the magnetic sensitive element is driven to rotate, and the magnetic flux inside it changes accordingly. For the magnetoresistor, its resistance value is changed; for the Hall element, the magnetic field affects the voltage signal it generates. As the position of the magnetic sensitive element changes, the generated electrical signal is proportional to the torsion angle and torque. Through the electronic circuit, the analog signal will be converted into a digital signal and transmitted to the vehicle's ECU (electronic control unit) for further analysis and control.

[0060] The plunger barrel assembly includes a plunger barrel 201, a second plunger 202 and a coil assembly 203;

[0061] The plunger barrel 201 is provided with a first plunger 104 and a second plunger 202, into which a magnetorheological fluid material is injected, and a coil assembly 203 is sleeved on the outside of the plunger barrel 201, and the first plunger 104 and the second plunger 202 are fixedly connected; specifically, the magnetorheological fluid material is used as a working medium, filling the cavity between the first plunger 104 and the second plunger 202 and the plunger barrel 201, and when the coil assembly 203 is energized, the magnetic particles in the magnetorheological fluid material quickly form a chain structure along the direction of the magnetic field, so that it changes from a Newtonian fluid to a solid-like state, thereby providing the required torque. By adjusting the current in the coil assembly 203, the torque of the hand feel simulator is controlled, and the stepless adjustment of the braking torque is achieved.

[0062] The second plunger 202 is provided with a first spring 204 at one end close to the first plunger 104, and a second spring 205 at the other end; specifically, after the end of the second plunger 202 close to the first plunger 104 is placed in the first spring 204, the first sealing ring 108 is put on and then installed in the tail of the housing 301, and a mounting groove is provided at the end of the second plunger 202 away from the first plunger 104, one end of the second spring 205 is fixed to the mounting groove, and the other end is pressed by a limit cover 302, and the limit cover 302 is fixed to the housing 301. The active return function of the steering wheel is realized by utilizing the mechanical characteristics of the balance of the compression spring force of the first spring 204 and the second spring 205. The first spring 204 and the second spring 205 balance the resistance generated by the magnetorheological fluid under different magnetic field strengths through their compression force, ensuring that the steering wheel can be smoothly and accurately returned to the center position after turning. The properties of the magnetorheological fluid material can be dynamically adjusted by changing the magnetic field strength, and the first spring 204 and the second spring 205 provide a mechanical method to assist this adjustment, so that the steering wheel's return force can maintain consistency and stability under different driving conditions; at the same time, the use of the spring enhances the stability of the system, especially when driving at high speeds or making sharp turns, the spring can help maintain the stability of the steering wheel and reduce the number of corrections made by the driver; the spring can absorb the impact and vibration in the movement of the plunger caused by changes in the magnetorheological fluid, reduce the noise and vibration of the system, and provide a more comfortable driving experience; the rapid response characteristics of the spring combined with the intelligent adjustment of the magnetorheological fluid can improve the response speed of the steering wheel to the driver's operation and achieve more precise steering control; allowing the system to automatically adjust the return force according to actual driving conditions, thereby improving driving adaptability and comfort.

[0063] In some specific implementations, see Figure 4, a plurality of sliders are arranged on the outer circumferential surface of the first plunger 104, and a plurality of chute grooves cooperating with the sliders are arranged on the inner circumferential surface of the plunger barrel 201, and the first plunger 104 slides along the plunger barrel 201, thereby pushing the magnetorheological fluid material to move. Preferably, the number of sliders and chute grooves is 4, and the sliders are evenly distributed on the outer circumferential surface of the first plunger 104, and the chute grooves are evenly distributed on the inner circumferential surface of the plunger barrel 201. When the first plunger 104 slides along the plunger barrel 201, the cooperation between the sliders and the chute grooves ensures the smooth movement of the first plunger 104 and reduces friction and wear. Through the precise cooperation of the mechanical structure and the intelligent response of the magnetorheological fluid material, precise control of the fluid properties is achieved.

[0064] In some specific implementations, see Figure 2 and Figure 3 , the plunger assembly also includes a sliding bearing 107 and a first sealing ring 108;

[0065] The sliding bearing 107 is press-fitted by interference fit at one end of the inner ring hole close to the input shaft 101; specifically, the end of the input shaft 101 close to the screw 103 is clearance-fitted with the sliding bearing 9, and the sliding bearing 9 can reduce the friction and wear of the screw 10 during movement, while providing support to ensure that the screw 103 can reciprocate smoothly and accurately; at the same time, the interference fit can ensure that the sliding bearing 107 is stably fixed on the screw 103, reducing the risk of loosening under high load or high-speed movement, reducing the relative movement between the screw 103 and the sliding bearing 107, reducing wear, and extending the service life.

[0066] The first sealing ring 108 is installed at one end of the first plunger 104 close to the second plunger 202 to prevent leakage of the magnetorheological fluid material and prevent external pollutants from entering to keep the system clean.

[0067] For some specific implementations, please continue to refer to Figure 2 and Figure 3 The plunger barrel assembly also includes a second sealing ring 206 and a third sealing ring 207; the second sealing ring 206 is arranged at the end of the plunger barrel 201 away from the first plunger 104; specifically, after the second sealing ring 206 is installed on the plunger barrel 201, the plunger barrel 201 is pressed onto the shell 301 to ensure a tight fit between the plunger barrel 201 and the shell 301. During the pressing process, the second sealing ring 206 is compressed. When the pressure is released, the second sealing ring 206 returns to its original state, thereby forming a seal between the plunger barrel 201 and the shell 301 to prevent leakage of the magnetorheological fluid material.

[0068] The third sealing ring 207 is installed at one end of the second plunger 202 close to the first plunger 104. Specifically, after the end of the second plunger 202 close to the first plunger 104 is placed in the first spring 204, the first sealing ring 108 is put on and then installed in the tail of the housing 301 to prevent leakage of the magnetorheological fluid material.

[0069] For some specific implementations, please continue to refer to Figure 2 and Figure 3 The hand feel simulator further includes a PCBA board 304, which is fixed on the housing 301, and the PCBA board 304 is integrated with a TAS communication interface 3041 and a power supply and CAN signal communication interface 3042;

[0070] The TAS communication interface 3041 is fixedly connected to the TAS sensor stator 105 interface for transmitting sensor data, such as torque and angle information of the steering wheel. Compared with the traditional design, the structure is more compact, avoiding the use of wiring harnesses and reducing costs.

[0071] The hand feel simulator is connected to the vehicle power supply, vehicle CAN signal and steering actuator CAN signal interface through the power supply and CAN signal communication interface 3042, respectively, to ensure that the hand feel simulator can receive power and exchange data with other electronic control units (ECU) of the vehicle.

[0072] For some specific implementations, please continue to refer to Figure 2 and Figure 3 The coil assembly 203 includes a power PIN angle 2031, and the power PIN angle 2031 is electrically connected to the PCBA board 304. Directly connecting the coil assembly 203 to the PCBA board can simplify the assembly process, reduce additional wiring work, and improve production efficiency. Direct connection can reduce the risk of poor contact and improve the stability and reliability of electrical connection.

[0073] For some specific implementations, please continue to refer to Figure 2 and Figure 3 The hand simulator also includes a shell 301, a limit cover 302 and an end cover 303. The limit cover 302 and the end cover 303 are arranged at both ends of the shell 301. Specifically, the shell 301 is the main part of the hand simulator, which is usually made of a solid material to accommodate all internal components of the simulator and protect the components from external influences. The limit cover 302 and the end cover 303 are respectively arranged at both ends of the shell 301 to close the shell, protect the internal components, and provide structural fixation and support. The limit cover 302 can also limit the movement range of the internal components to prevent damage caused by excessive displacement.

[0074] The input shaft 101 passes through the end cover 303 and is fixedly connected thereto; specifically, the input shaft 101 passes through the end cover 303 and is fixed to the end cover 303 by a deep groove ball bearing, thereby ensuring the stable positioning of the input shaft 101 in the housing 301 and reducing friction during movement, while reducing energy loss due to friction and wear, and improving the efficiency and reliability of the entire system.

[0075] The second spring 205 is fixed to the limit cover 302 at one end away from the second plunger 202. The second spring 205 provides a preload force or a restoring force to ensure that the plunger assembly in the hand feel simulator can work stably and provide damping when necessary; the preload force of the second spring 205 can help the simulator maintain its initial position when there is no external force, or help it return to the center position after a steering operation.

[0076] For some specific implementations, please continue to refer to Figure 2 and Figure 3 A cover 305 is provided on the PCBA board 304, and the cover 305 is fixedly connected with the shell 301. The cover 305 can protect the electronic components on the PCBA board 304 and prevent the intrusion of dust, moisture and other pollutants, thereby extending the service life of the electronic components and maintaining stable performance; the fixed connection between the cover 305 and the shell 301 can be achieved in a variety of ways, including screw connection, snap connection, welding or bonding, etc., to ensure that the cover 305 is firmly fixed on the shell to prevent loosening due to vibration or impact.

[0077] In some specific implementations, see Figure 4 The plunger barrel 201 is provided with a liquid injection port, and a sealing plug 208 is provided on the liquid injection port; preferably, the sealing plug 208 can be a sealing screw, and the liquid injection port is an opening on the plunger barrel 201, which is used to inject or discharge the magnetorheological fluid material into the plunger barrel 201; the liquid injection port can also ensure that the gas in the cavity of the plunger barrel 201 is discharged, and prevent the gas from forming bubbles in the magnetorheological fluid, which affects the performance of the magnetorheological fluid and the movement of the plunger. After the gas in the plunger barrel 201 is discharged, the sealing plug 208 is screwed on to close the plunger barrel 201 to form a seal to prevent the magnetorheological fluid from leaking and external contaminants from entering. It can be used in conjunction with a sealing gasket or an O-ring to provide a better sealing effect.

[0078] See also Figure 5 and Figure 6 The embodiment of the present application also provides a control method for a plunger-type wire-controlled feel simulator, comprising:

[0079] Obtaining torque angle information, wherein the torque angle information is collected by a TAS sensor stator and a TAS sensor rotor;

[0080] Obtain vehicle speed information and steering actuator status information;

[0081] Based on the torque angle information, the vehicle speed information and the steering actuator state information, a required hand-feel damping force is obtained;

[0082] Based on the desired hand-feel damping force, the current in the coil assembly is adjusted.

[0083] In some specific implementations, see Figure 5 When the steering wheel turns, the TAS sensor stator 105 and the TAS sensor rotor 106 measure the torque angle information of the input shaft 101 and send the torque angle information to the ECU. The ECU obtains the required hand-feel damping force based on the received torque angle signal, vehicle speed signal (provided by the vehicle CAN), and steering actuator status information (provided by the private CAN); the screw 103 drives the first plunger 104 and the second plunger 202 to move in the plunger barrel 201, thereby pushing the magnetorheological fluid to move, and the magnetorheological fluid produces a damping feel. The ECU controls the current of the coil assembly 203, and the coil assembly 203 generates a corresponding electromagnetic field to change the damping size of the magnetorheological fluid and control the hand-feel damping. Among them, the hand-feel damping force = the center diameter of the screw thread × tan (screw lead angle + equivalent friction angle) × (magnetorheological fluid damping + first spring stiffness × first spring deformation + second spring stiffness × second spring deformation + first plunger and plunger barrel friction + second plunger and housing friction) / 2 + screw thread friction torque.

[0084] In some specific implementations, see Figure 6 When the steering wheel is not in the neutral position, the current of the control coil assembly 203 is controlled to achieve active return. The required active return force is calculated as follows:

[0085] Active return force (left turn state) = screw thread diameter × tan (screw lead angle + equivalent friction angle) × (first spring stiffness × first spring deformation - second spring stiffness × second spring deformation - first plunger and plunger barrel friction - second plunger and housing friction - magnetorheological fluid damping) / 2 - screw thread friction torque.

[0086] Active return force (right turn state) = screw thread diameter × tan (screw lead angle + equivalent friction angle) × (second spring stiffness × second spring deformation - first spring stiffness × first spring deformation - first plunger and plunger barrel friction - second plunger and housing friction - magnetorheological fluid damping) / 2 - screw thread friction torque.

[0087] In some specific embodiments, when the hand simulator is powered off, no current flows in the coil assembly 203. In the absence of an electromagnetic field, the damping characteristics of the magnetorheological fluid will be reduced to a minimum, that is, in a zero magnetic field damping state. The first spring 204 and the second spring 205 return to an initial compression state, so that the mechanical structure of the hand simulator returns to a preset neutral equilibrium position. In the neutral equilibrium state, the hand simulator does not require additional force to maintain its position, thereby realizing the neutral position maintenance function.

[0088] In some specific embodiments, the present application also includes a variable end soft limit, which is intended to reduce the impact on the mechanical end when the input shaft speed of the hand feel simulator is fast, and to adapt to the requirements of different transmission ratios and different vehicles for the number of steering wheel turns, and to apply a certain damping torque to the steering wheel within the function activation range. When the steering wheel position enters the soft limit end travel position, the current of the ECU control coil assembly 203 increases rapidly, causing the electromagnetic field magnetic flux to increase rapidly, the hand feel damping instantly reaches the preset damping peak, and the steering wheel cannot be turned, so as to adapt to different driving conditions and protect the mechanical structure of the hand feel simulator.

[0089] In some specific embodiments, the present application also includes a mechanical limit at the end of the steering angle, which refers to a redundant mechanical limit set to prevent software function abnormalities under the premise of the soft limit. The mechanical limit at the end of the steering angle is a supplement to the soft limit controlled by the software, providing an additional physical protection measure. This double protection ensures that even if the software control fails, the steering wheel will not be excessively rotated. The implementation method is: when the steering wheel rotates, the first plunger 104 and the second plunger 202 push the magnetorheological fluid to flow, and the housing 301 and the limit cover 302 limit the axial displacement of the second plunger 202, thereby limiting the rotation angle of the steering wheel. The distance between the end face of the second plunger 202 close to one end of the first plunger 104 and the limit end face of the housing 301 is equal to the distance between the end face of the second plunger 202 close to one end of the limit cover 302 and the limit cover 302, and the distance = the screw lead × the number of turns on one side of the steering wheel. By adjusting the number of turns of the steering wheel, the setting of the mechanical limit can be adjusted. By combining the mechanical limit with the soft limit, a dual protection mechanism is provided. The soft limit is achieved by the ECU controlling the electromagnetic field and the damping characteristics of the magnetorheological fluid, while the mechanical limit limits the rotation angle of the steering wheel through the physical structure to prevent excessive rotation caused by software malfunction, thereby protecting the safety of the driver and the vehicle.

[0090] The plunger-type wire-controlled feel simulator provided in the embodiment of the present application adopts a redundant design, and all signals are designed in dual paths. When one signal is lost or fails, the normal operation of the feel simulator can be guaranteed.

[0091] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A plunger-type wire-controlled feel simulator, characterized in that: Includes a plunger assembly and a plunger barrel assembly; The plunger assembly comprises an input shaft (101), a torsion bar (102), a screw rod (103) and a first plunger (104); The input shaft (101) is a hollow structure, on which a TAS sensor stator (105) is arranged; One end of the torsion bar (102) passes through the input shaft (101) and is fixedly connected thereto, and the other end is interference fit into the inner ring hole of the screw rod (103); The screw (103) is threadedly connected to the first plunger (104), and a TAS sensor rotor (106) is arranged on the screw; The plunger barrel assembly comprises a plunger barrel (201), a second plunger (202) and a coil assembly (203); The first plunger (104) and the second plunger (202) are arranged in the plunger barrel (201), and magnetorheological fluid material is injected therein; the coil assembly (203) is sleeved on the outside of the plunger barrel (201), and the first plunger (104) and the second plunger (202) are fixedly connected; The second plunger (202) is provided with a first spring (204) at one end close to the first plunger (104), and a second spring (205) at the other end.

2. A plunger-type wire-controlled feel simulator according to claim 1, characterized in that: A plurality of sliding blocks are arranged on the outer circumferential surface of the first plunger (104), and a plurality of sliding grooves matching with the sliding blocks are opened on the inner circumferential surface of the plunger barrel (201). The first plunger (104) slides along the plunger barrel (201), thereby pushing the magnetorheological fluid material to move.

3. The plunger-type wire-controlled feel simulator according to claim 1, characterized in that: The plunger assembly also includes a sliding bearing (107) and a first sealing ring (108); The sliding bearing (107) is press-fitted into one end of the inner ring hole close to the input shaft (101); The first sealing ring (108) is installed on one end of the first plunger (104) close to the second plunger (202).

4. The plunger-type wire-controlled feel simulator according to claim 1, characterized in that: The plunger barrel assembly further comprises a second sealing ring (206) and a third sealing ring (207), wherein the second sealing ring (206) is arranged at an end of the plunger barrel (201) away from the first plunger (104); The third sealing ring (207) is installed on an end of the second plunger (202) close to the first plunger (104).

5. The plunger-type wire-controlled feel simulator according to claim 1, characterized in that: The hand feel simulator further comprises a PCBA board (304), the PCBA board (304) being fixed on the housing (301), and the PCBA board (304) being integrated with a TAS communication interface (3041) and a power supply and CAN signal communication interface (3042); The TAS communication interface (3041) is fixedly connected to the TAS sensor stator (105) interface; The hand feel simulator is connected to the vehicle power supply, vehicle CAN signal and steering actuator CAN signal interface respectively through the power supply and CAN signal communication interface (3042).

6. A plunger-type wire-controlled feel simulator according to claim 5, characterized in that: The coil assembly (203) comprises a power PIN angle (2031), and the power PIN angle (2031) is electrically connected to the PCBA board (304).

7. The plunger-type wire-controlled feel simulator according to claim 1, characterized in that: The hand feel simulator further comprises a housing (301), a limiting cover (302) and an end cover (303), wherein the limiting cover (302) and the end cover (303) are arranged at two ends of the housing (301); The input shaft (101) passes through the end cover (303) and is fixedly connected thereto; One end of the second spring (205) facing away from the second plunger (202) is fixed to the limiting cover (302).

8. The plunger-type wire-controlled feel simulator according to claim 5, characterized in that: The PCBA board (304) is provided with a cover (305), and the cover (305) is matched and fixedly connected to the housing (301).

9. The plunger-type wire-controlled feel simulator according to claim 1, characterized in that: The plunger barrel (201) is provided with a liquid injection port, and a sealing plug (208) is provided on the liquid injection port.

10. A control method for a plunger-type wire-controlled feel simulator, characterized in that: include: Obtaining torque angle information, wherein the torque angle information is collected by a TAS sensor stator (105) and a TAS sensor rotor (106); Obtain vehicle speed information and steering actuator status information; Based on the torque angle information, the vehicle speed information and the steering actuator state information, a required hand-feel damping force is obtained; Based on the required hand-feel damping force, the current in the coil component (203) is adjusted.

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