Force feedback device based on direct drive motor and magnetic powder damper and control method and control system thereof

Abstract

The invention discloses a force feedback device based on a direct drive motor and a magnetic powder damper and a control method and a control system of the force feedback device, and relates to the technical field of driving simulation. The device comprises a rotary adjusting support, a servo motor, an angle sensor, the magnetic powder damper, a steering column and a PLC which are coaxially arranged; the rotary adjusting support simulates a real cockpit structure and supports the whole device. The angle sensor detects the angle and the angular speed of a steering wheel, and the PLC calculates the needed torque based on the vehicle speed, steering wheel parameters and empirical coefficients and controls the servo motor and the magnetic powder damper to work. The servo motor is used for simulating and generating aligning torque and assisting torque according to the control of the PLC, the magnetic powder damper is controlled to simulate and generate damping torque, and the torque is fed back to a steering wheel through the steering column. According to the scheme, through component division and precise control, the simulation authenticity and response speed are improved, and the method is suitable for driving training, vehicle simulation testing and other scenes.

Description

Technical Field

[0001] This application relates to the field of driving simulation technology, and in particular to a force feedback device and its control method and control system based on a direct drive motor and a magnetic powder damper. Background Technology

[0002] In the scientific research field, driving simulators are widely used in autonomous driving simulation and intelligent cockpit automation testing, gradually becoming a routine method and tool in automotive R&D. They can significantly reduce testing costs, shorten testing cycles, improve the consistency of repeated tests, and safely reproduce extreme and dangerous scenarios in a laboratory environment. In driving simulators, driving controls are an essential component, serving as the core input module for driver-in-the-loop control of the vehicle. Typical simulated driving controls mainly include the steering wheel, accelerator pedal, brake pedal, and gear shift lever, among which the force feedback steering wheel has the most complex structure and function, and is the most critical.

[0003] Force feedback steering wheels need to dynamically adjust the output torque according to the driving environment to accurately simulate the various forces transmitted to the driver's hands by the steering system in a real vehicle. Currently, the mainstream types on the market are gear drive and belt drive: gear drive is inexpensive, but it is prone to "tooth grinding" during transmission, affecting the driving experience, and the gear base is noisy; belt drive avoids the "tooth grinding" problem and reduces noise, but belt pulley slippage can occur, resulting in energy loss and reduced transmission accuracy.

[0004] Therefore, overcoming the shortcomings of existing technologies and providing a solution that can accurately simulate the force of a real driving steering system fed back to the driver's hands through the steering wheel is of great necessity for improving the simulation experience and adapting to diverse experimental scenarios. Summary of the Invention

[0005] The purpose of this application is to provide a force feedback device and its control method and control system based on a direct drive motor and a magnetic powder damper, which can accurately simulate the force of a real driving steering system that is fed back to the driver's hand through the steering wheel.

[0006] To achieve the above objectives, this application provides the following solution:

[0007] In a first aspect, this application provides a force feedback device based on a direct-drive motor and a magnetic powder damper, comprising: a rotary adjustment bracket, a servo motor, an angle sensor, a magnetic powder damper, a steering column, and a PLC; a steering wheel is provided at the end of the steering column, and the servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel are coaxially arranged; the rotary adjustment bracket is fixed to the side wall of the simulated cockpit to simulate the arrangement of the steering wheel transmission structure in a real cockpit and to support the servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel; the servo motor is mounted on the rotary adjustment bracket and is used to generate corresponding torque according to the control command of the PLC to simulate the self-centering torque generated by the wheel returning to center and the assist force applied by the assist motor. The torque is fed back to the driver through the steering column and the steering wheel mounted on the steering column; the angle sensor is used to detect the steering wheel angle and steering wheel angular velocity and transmit them to the PLC for force feedback simulation calculation; the magnetic powder damper is used to generate damping force under the control of the PLC, simulating the damping torque between the friction between components in the real transmission system, and is fed back to the driver through the steering column and the steering wheel mounted on the steering column; the PLC is used to perform force feedback simulation calculation based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients, to obtain the required return torque, assist torque and damping torque, and to control the servo motor to generate return torque and assist torque through the servo driver, and to control the magnetic powder damper to generate damping torque.

[0008] Optionally, it also includes a power supply; the power supply is a 220V power supply used to power the servo driver to drive the servo motor; the power supply also provides a 24V power supply through step-down output to power the PLC, magnetic powder damper and angle sensor.

[0009] Optionally, during force feedback simulation, the servo motor adopts torque mode, and the PLC sends the sum of the return torque and assist torque as the target value to the servo driver, thereby controlling the servo motor to generate the target torque; during autonomous driving simulation, the servo motor adopts angle mode, and the PLC receives the angle value sent by the simulation software and controls the servo driver to control the servo motor to rotate the steering wheel by the corresponding angle according to the corresponding angular velocity.

[0010] Optionally, the PLC drives a servo motor to limit the steering wheel's rotation range to ±540°, achieving a soft-limit effect. When the limit value is reached, the servo motor will apply a limiting torque of 10 N·m to prevent the steering wheel from rotating beyond the limit position.

[0011] Optionally, the end of the steering column can be machined with different types of splines to achieve connection with different steering wheels.

[0012] Optionally, the PLC can change the magnetic field shape inside the magnetic powder damper by adjusting the input current of the magnetic powder damper. The internal magnetic powder will be arranged along the direction of the magnetic field to form a chain structure. The friction in this process will consume energy, thereby slowing down the vibration and movement of the mechanical system and generating a damping torque.

[0013] Secondly, this application provides a control method for a force feedback device based on a direct-drive motor and a magnetic powder damper, comprising the following steps:

[0014] Acquire vehicle speed data, steering wheel angle, and steering wheel angular velocity during simulated driving.

[0015] The angular acceleration of the steering wheel can be calculated by differentiating the angular velocity of the steering wheel.

[0016] Force feedback simulation calculations are performed based on vehicle speed data, steering wheel angle, steering wheel angular velocity, and preset empirical coefficients to obtain the required return torque, assist torque, and damping torque.

[0017] Based on the sum of the return torque and the assist torque, the servo motor is controlled by the servo driver to generate a corresponding torque, simulating the return torque generated by the wheels returning to center on their own and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0018] The current of the magnetic powder damper is adjusted according to the damping torque to generate a corresponding torque, simulating the damping torque between the friction between components in a real transmission system; the corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0019] Alternatively, the restoring torque can be calculated using the following formula:

[0020] T z =K z ·θ+(C z0 +C z1 ·V).

[0021] Among them, T z For the restoring torque, K z C is the angular coefficient of the restoring torque. z0 C is the offset of the return torque as a function of the velocity value. z1 C is the coefficient of the restoring torque speed. z0 and C z1 All are constants, θ is the steering wheel angle, and V is the vehicle speed data.

[0022] The assist torque is calculated using the following formula:

[0023]

[0024] Among them, T t To assist torque, K t To assist the torque angle coefficient, C t0 To determine the offset of the assist torque gain with speed, C t1 To assist the torque-speed coefficient, C t0 and C t1 All are constants, and b is the transmission ratio.

[0025] The damping moment is calculated using the following formula:

[0026] T d =(C d0 +C d1 ·V)·ω.

[0027] Among them, T d For the damping torque, C d0 C is the offset of the damping torque gain with respect to the velocity value. d1 C is the damping torque velocity coefficient. d0 and C d1 All are constants, and ω is the angular velocity of the steering wheel.

[0028] Optionally, when the vehicle speed data is 0-20 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V, the assist torque angle coefficient is -1.25×10 3 V+0.1; When the vehicle speed data is 20-60km / h, the return torque angle coefficient is 3.75×10. 4 V+7.5×10 3 The assist torque angle coefficient is -6.25×10. 4 V+8.75×10 2 When the vehicle speed is 60-100 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V-1.5×10 2 The assist torque angle coefficient is -2.5×10. 3 V+0.2; When the vehicle speed is greater than 100km / h, the return torque angle coefficient is 0.1 and the assist torque angle coefficient is -0.025.

[0029] Thirdly, this application provides a control system for a force feedback device based on a direct-drive motor and a magnetic powder damper, comprising:

[0030] The simulated driving data acquisition module is used to acquire vehicle speed data, steering wheel angle, and steering wheel angular velocity during simulated driving.

[0031] The steering wheel angular velocity calculation module is used to differentiate the steering wheel angular velocity and calculate the steering wheel angular acceleration.

[0032] The force feedback simulation calculation module is used to perform force feedback simulation calculations based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients of the simulated driving, so as to obtain the required return torque, assist torque and damping torque.

[0033] The servo motor drive module is used to control the servo motor to generate corresponding torque based on the sum of the self-centering torque and the assist torque, simulating the self-centering torque generated by the wheels returning to center and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0034] The magnetic powder damper drive module is used to adjust the current of the magnetic powder damper according to the damping torque to generate a corresponding torque, simulating the damping torque between the friction of components in a real transmission system; the corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0035] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0036] This application provides a force feedback device and its control method and control system based on a direct-drive motor and a magnetic powder damper. In this force feedback device, a rotary adjustment bracket is fixed to the side wall of a simulated cockpit, simulating the arrangement of the steering wheel transmission structure in a real cockpit, and supporting a servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel. The PLC performs force feedback simulation calculations based on the simulated driving speed data, steering wheel angle, steering wheel angular velocity, and preset empirical coefficients to obtain the required return torque, assist torque, and damping torque. The servo motor generates corresponding torque according to the control commands of the PLC, simulating the return force generated by the wheels returning to center on their own. The torque and assist torque applied by the servo motor and the damping force generated by the magnetic powder damper under the control of the PLC simulate the damping torque between the friction between components in a real transmission system. These torques are fed back to the driver through the steering column and the steering wheel mounted on the steering column. In this application, the transmission structure layout of the real cockpit is simulated by rotating the adjustment bracket. With the coaxial setting of each component, the error and energy loss in the transmission process are effectively reduced, ensuring that the torque generated by the servo motor and the magnetic powder damper can be accurately transmitted to the steering wheel, allowing the driver to obtain a stable and consistent force feedback feeling. Furthermore, through the division of labor and cooperation between the servo motor and the magnetic powder damper, the accurate simulation of torque is achieved. In addition, the PLC, based on a multi-parameter dynamic calculation mechanism, ensures the adaptability of the force feedback, adjusts the magnitude of the assist torque according to the vehicle speed, and dynamically changes the return torque according to the steering operation, making the simulation effect closer to the driving characteristics of a real vehicle. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a force feedback device based on a direct drive motor and a magnetic powder damper, provided as an embodiment of this application.

[0039] Figure 2 This is a schematic diagram of signal transmission and power supply for a force feedback device based on a direct-drive motor and a magnetic powder damper, provided as an embodiment of this application.

[0040] Figure 3 A flowchart illustrating a force feedback device and its control method based on a direct-drive motor and a magnetic powder damper, provided as an embodiment of this application.

[0041] Figure 4 This is a functional block diagram of a force feedback device and its control system based on a direct drive motor and a magnetic powder damper, provided as an embodiment of this application. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0043] In driving simulators, driving controls are an essential component, serving as the primary input module for the driver's on-loop control of the vehicle, used to perform acceleration, deceleration, gear shifting, and steering. It's important to note that the driving kit in a driving simulator differs significantly from that of a real vehicle, primarily in the following two aspects:

[0044] ① The usage environments are different. Taking the steering wheel as an example, the feel of a steering wheel in a real car is based on the chassis suspension structure, such as the camber and caster angles. The force is transmitted from the road surface to the wheels, and then through the transmission system to the steering wheel, generating hand force, which is directly related to the vehicle speed and the steering wheel angle. However, in a driving simulator, there is neither actual vehicle speed nor the friction between the tires and the road surface, and even the steering system no longer exists.

[0045] ②The purposes of use are different. The driving control components of a real vehicle can complete vehicle control through mechanical structure, while the driving control components of a driving simulator need to convert relevant operation inputs into control signals and send them to the simulation software or real-time system. In special cases, they also need to accept the reverse control operation of the simulation software.

[0046] Based on the above analysis, the driving controls in a driving simulator need to meet the following two conditions:

[0047] ① It has a similar feel to actual driving, such as resistance, rebound, and vibration.

[0048] ② It can perform X-axis and Y-axis control and reverse control of vehicles in simulation software.

[0049] Conventional simulated driving controls mainly include the steering wheel, accelerator pedal, brake pedal, and gear shift lever. Among these, the force feedback steering wheel is the most important and complex. A force feedback steering wheel should adjust its output torque according to the driving environment, simulating various forces in the steering system during real-world driving, ultimately manifesting as force feedback to the driver's hands. The main types of force feedback steering wheels on the market are gear-driven and belt-driven. Gear-driven steering is inexpensive, but its disadvantages include the tendency for "tooth grinding" during transmission, affecting the user experience, and the relatively loud noise from the gears inside the base. Belt-driven steering avoids the "tooth grinding" problem of gear-driven steering and reduces noise, but belt slippage leads to energy loss and reduces precision.

[0050] This application addresses the industry's needs and current technological status regarding force feedback steering wheels, proposing a combination of a direct-drive motor and a magnetic powder damper. Its key feature is that the direct connection between the servo motor and the steering wheel significantly improves the system's response speed and increases the maximum applicable feedback force. The magnetic powder damper, as a supplement, generates adjustable constant torque through current variations, providing a more coherent and nuanced system damping simulation while reducing the complexity of the servo motor control algorithm. Combined with flexible wheel switching and steering wheel counter-control functions, it can effectively handle a wide variety of experimental scenarios.

[0051] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] This application provides a force feedback device based on a direct-drive motor and a magnetic powder damper. In one exemplary embodiment, such as... Figure 1As shown, the system includes: a rotary adjustment bracket, a servo motor, an angle sensor, a magnetic powder damper, a steering column, and a PLC. A steering wheel is mounted at the end of the steering column, and the servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel are coaxially arranged. In one feasible implementation, the steering wheel, steering column, magnetic powder damper, angle sensor, and servo motor are coaxially connected via a coupling. For ease of expansion, the end of the steering column is machined with different types of splines to allow connection to different steering wheels. Through different types of splines, the steering column can be connected to different types of steering wheel surfaces, enabling flexible replacement and control of driving input.

[0053] The rotating adjustment bracket is fixed to the side wall of the simulated cockpit to simulate the layout of the steering wheel transmission structure in a real cockpit, and supports the servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel. The rotating adjustment bracket can be fixed in any position as needed. Unlike a real vehicle, the force feedback device proposed in this embodiment no longer needs to be connected to the steering system below, nor does it rely on the hand force that can be felt by both hands during vehicle movement, which is applied to the tires by the road surface and transmitted upwards to the steering wheel surface. Instead, it directly simulates the steering column torque at different vehicle speeds and steering wheel angles through the servo motor and magnetic powder damper, and transmits it to the hands holding the steering wheel.

[0054] Furthermore, the angle sensor detects the steering wheel angle and angular velocity and transmits them to the PLC for force feedback simulation calculations. The PLC performs force feedback simulation calculations based on the vehicle speed data, steering wheel angle, steering wheel angular velocity, and preset empirical coefficients from the simulated driving, to obtain the required return torque, assist torque, and damping torque. It then controls the servo motor to generate the return torque and assist torque via a servo driver, and controls the magnetic powder damper to generate the damping torque.

[0055] When conducting simulated driving, there must be a virtual scene and a virtual vehicle. The control parameters are input into the vehicle dynamics through the driving control device to calculate the real-time motion state of the controlled virtual vehicle, which includes the vehicle speed data V. The PLC captures the vehicle speed data V sent in 5ms cycles through the UDP communication protocol.

[0056] The angle sensor continuously collects the steering wheel's rotation angle θ and angular velocity ω, and uses a differential calculation algorithm to differentiate the angular velocity to obtain the angular acceleration α. ​​The PLC acquires the rotation angle and angular velocity values ​​at 5ms intervals via the CAN protocol and calculates the angular acceleration.

[0057] The self-centering torque refers to the force exerted by the road surface on the tires when the vehicle is moving and the tires are turning, due to the presence of camber and caster angles. This friction causes the wheels to press against the road surface in a non-perpendicular direction, creating a tendency for the wheels to return to center. This torque is transmitted to the steering wheel through the steering system's physical structure, manifesting as the steering wheel automatically returning to zero. This force is called the self-centering torque T. z If the driver wants to continue controlling the steering wheel, they need to overcome this torque.

[0058] The return torque is positively correlated with the steering wheel angle and vehicle speed, and is defined in this embodiment based on an empirical formula as follows:

[0059] T z =K z ·θ+(C z0 +C z1 ·V).

[0060] Among them, T z For the restoring torque, K z C is the angular coefficient of the restoring torque. z0 C is the offset of the return torque as a function of the velocity value. z1 C is the coefficient of the restoring torque speed. z0 and C z1 All are constants, and in this embodiment, they are taken as value C. z0 =0.9, C z1 =0.007, where θ is the steering wheel angle and V is the vehicle speed. The conditions for the return torque to take effect are "the angle and angular velocity are opposite" and "the vehicle speed is greater than 0", and the applied direction is opposite to the angle θ value.

[0061] The assist torque simulates the torque applied by the power steering motor in a real vehicle. Its direction is generally consistent with the driving intention, and its function is to reduce the hand force required to turn the steering wheel, achieving easier steering operation. In reality, the electric power steering strategy is determined through a calibration process; therefore, the assist torque in this embodiment is obtained by fitting the actual vehicle's power steering strategy. The assist torque is calculated according to the following formula:

[0062]

[0063] Among them, T t To assist torque, K t To assist the torque angle coefficient, C t0 To determine the offset of the assist torque gain with speed, C t1 To assist the torque-speed coefficient, C t0 and C t1 All are constants, and in this embodiment, they are taken as value C. t0 =1,C t1=0.01. b is the transmission ratio. The condition for the assist torque to take effect is that "the angle and angular velocity are in the same direction", and the applied direction is the same as the angle θ value.

[0064] Damping torque refers to the torque that resists steering wheel rotation caused by friction and other factors between mechanical transmission components in a vehicle's steering system. It only occurs when the steering wheel has a tendency to rotate or actually rotates. The fitting calculation formula is as follows:

[0065] T d =(C d0 +C d1 ·V)·ω.

[0066] Among them, T d For the damping torque, C d0 C is the offset of the damping torque gain with respect to the velocity value. d1 C is the damping torque velocity coefficient. d0 and C d1 All are constants, and in this embodiment, they are taken as value C. d0 =5×10 4 C d1 =1×10 4 ω is the angular velocity of the steering wheel. The condition for the damping torque to take effect is that "the angular velocity is not 0", and the applied direction is the same as the angular velocity ω.

[0067] The servo motor, mounted on a rotary adjustment bracket, generates corresponding torque according to PLC control commands. This simulates the self-centering torque of the wheels and the assist torque applied by the power steering motor, and is fed back to the driver via the steering column and the steering wheel mounted on it. The magnetic powder damper, controlled by the PLC, generates damping force to simulate the damping torque between components in a real drivetrain. This force is also fed back to the driver via the steering column and the steering wheel mounted on it, ultimately recreating a realistic driving feel.

[0068] Specifically, the PLC adjusts the input current of the magnetic powder damper, thereby altering the internal magnetic field configuration. The internal magnetic powder aligns along the magnetic field direction, forming a chain-like structure. Friction during this process consumes energy, thus mitigating the vibration and motion of the mechanical system and generating a damping torque. By changing the input current, the magnitude of the generated damping torque can be precisely controlled to simulate the system damping torque T of a real vehicle's steering system. d The target value has the advantage of separating the damping torque from the other two torques, avoiding mutual coupling that would reduce the adjustability of the model. Furthermore, since the generation mechanism and corresponding speed of the damping torque using a magnetic powder damper are more similar, using a magnetic powder damper is more delicate and realistic than using a servo motor to simulate the damping torque.

[0069] As an optional implementation method, the parameters in the above three torque calculation formulas can be adjusted according to the different calibration targets of different vehicle models and the different feel of different users, which has high flexibility and adaptability.

[0070] In this embodiment, the PLC drives a servo motor to limit the rotation range of the steering wheel to ±540°, achieving a soft limit effect. When the limit value is reached, the servo motor will apply a limiting torque of 10 N·m to prevent the steering wheel rotation angle from exceeding the limit position.

[0071] In one exemplary embodiment, the force feedback device based on a direct-drive motor and a magnetic powder damper further includes a power supply; as Figure 2 The diagram shown illustrates the signal transmission and power supply of the force feedback device. The power supply is 220V, used to power the servo driver to drive the servo motor. The power supply also outputs 24V through step-down, which is used to power the PLC, magnetic powder damper, and angle sensor.

[0072] As an optional implementation, during force feedback simulation, the servo motor operates in torque mode. The PLC sends the sum of the return torque and assist torque as the target value to the servo driver, thereby controlling the servo motor to generate the target torque. During autonomous driving simulation, the servo motor operates in angle mode. The PLC receives the angle value sent by the simulation software and controls the servo driver to control the servo motor to rotate the steering wheel by the corresponding angle at the corresponding angular velocity. In the case of autonomous driving, when the autonomous driving algorithm controls the lateral movement of the virtual vehicle, the steering wheel needs to rotate by the corresponding angle. Therefore, the steering wheel needs to be controllable in reverse. In this case, the servo motor is set to angle mode, the PLC receives the angle value sent by the simulation software and controls it to rotate to the corresponding position, and the rotation speed can be set.

[0073] This application also provides a method for controlling the force feedback device based on a direct-drive motor and a magnetic powder damper as described above. In an exemplary embodiment, such as Figure 3 As shown, a control method for a force feedback device based on a direct-drive motor and a magnetic powder damper is provided, including the following steps:

[0074] S1. Obtain vehicle speed data, steering wheel angle, and steering wheel angular velocity from the simulated driving.

[0075] S2. Differentiate the angular velocity of the steering wheel to calculate the angular acceleration of the steering wheel.

[0076] S3. Based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients of the simulated driving, perform force feedback simulation calculations to obtain the required return torque, assist torque and damping torque.

[0077] In this embodiment, the corrective torque is calculated according to the following formula:

[0078] T z =K z ·θ+(C z0 +C z1 ·V).

[0079] Among them, T z For the restoring torque, K z C is the angular coefficient of the restoring torque. z0 C is the offset of the return torque as a function of the velocity value. z1 C is the coefficient of the restoring torque speed. z0 and C z1 All are constants, θ is the steering wheel angle, and V is the vehicle speed data.

[0080] The assist torque is calculated using the following formula:

[0081]

[0082] Among them, T t To assist torque, K t To assist the torque angle coefficient, C t0 To determine the offset of the assist torque gain with speed, C t1 To assist the torque-speed coefficient, C t0 and C t1 All are constants, and b is the transmission ratio.

[0083] The damping moment is calculated using the following formula:

[0084] T d =(C d0 +C d1 ·V)·ω.

[0085] Among them, T d For the damping torque, C d0 C is the offset of the damping torque gain with respect to the velocity value. d1 C is the damping torque velocity coefficient. d0 and C d1 All are constants, and ω is the angular velocity of the steering wheel.

[0086] S4. Based on the sum of the return torque and the assist torque, the servo motor is controlled by the servo driver to generate a corresponding torque, simulating the return torque generated by the wheels returning to center on their own and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0087] S5. Adjust the current of the magnetic powder damper according to the damping torque to generate a corresponding torque, simulating the damping torque between the friction of components in a real transmission system; the corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0088] As a specific example, when the vehicle speed is 0-20 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V, the assist torque angle coefficient is -1.25×10 3 V+0.1; When the vehicle speed data is 20-60km / h, the return torque angle coefficient is 3.75×10. 4 V+7.5×10 3 The assist torque angle coefficient is -6.25×10. 4 V+8.75×10 2 When the vehicle speed is 60-100 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V-1.5×10 2 The assist torque angle coefficient is -2.5×10. 3 V+0.2; When the vehicle speed is greater than 100km / h, the return torque angle coefficient is 0.1 and the assist torque angle coefficient is -0.025.

[0089] Compared with the prior art, the technical means provided by the above embodiments of this application have many beneficial effects:

[0090] Firstly, the precise simulation of torque is achieved through the division of labor and cooperation between the servo motor and the magnetic powder damper. The servo motor is specifically responsible for simulating the wheel return torque and the assist torque of the power assist motor, while the magnetic powder damper focuses on simulating the damping torque of the transmission system. This targeted design allows for a more realistic reproduction of the characteristics of different types of torque, avoiding performance compromises when a single component undertakes multiple torque simulations, and significantly improving the realism of force feedback.

[0091] Secondly, the PLC, based on a multi-parameter dynamic calculation mechanism, ensures the adaptability of force feedback. It combines vehicle speed data, steering wheel angle, angular velocity, and preset empirical coefficients from simulated driving to calculate and match torque requirements under different driving conditions in real time. For example, it adjusts the power assist according to changes in vehicle speed and dynamically changes the return force according to steering operations, making the simulation effect closer to the driving characteristics of a real vehicle.

[0092] Third, the structural design enhances the reliability of force feedback. The rotating adjustment bracket simulates the transmission structure of a real cockpit, and the coaxial arrangement of various components effectively reduces errors and energy loss during transmission, ensuring that the torque generated by the servo motor and magnetic powder damper can be accurately transmitted to the steering wheel, allowing the driver to obtain a stable and consistent force feedback experience.

[0093] Fourth, the refined control method improves the response speed. By differentiating the steering wheel angular velocity to obtain angular acceleration, the precision of torque calculation is further optimized. Combined with the servo driver's precise control of the servo motor and the magnetic powder damper's rapid response through current adjustment of damping, the entire system can quickly follow the driver's operation changes, achieving real-time force feedback and enhancing the immersive experience of simulated driving.

[0094] In summary, the technical solutions provided by the above embodiments of this application have comprehensive advantages in simulation realism, control precision, and response speed, which can provide a force feedback experience that is highly close to reality for simulated driving, and are suitable for various scenarios such as driver training and vehicle simulation testing.

[0095] Based on the same inventive concept, embodiments of this application also provide a control system for implementing the control method described above. In an exemplary embodiment, such as... Figure 4 As shown, a control system for a force feedback device based on a direct-drive motor and a magnetic powder damper is provided, including the following functional modules:

[0096] The simulated driving data acquisition module is used to acquire vehicle speed data, steering wheel angle, and steering wheel angular velocity during simulated driving.

[0097] The steering wheel angular velocity calculation module is used to differentiate the steering wheel angular velocity and calculate the steering wheel angular acceleration.

[0098] The force feedback simulation calculation module is used to perform force feedback simulation calculations based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients of the simulated driving, so as to obtain the required return torque, assist torque and damping torque.

[0099] The servo motor drive module is used to control the servo motor to generate corresponding torque based on the sum of the self-centering torque and the assist torque, simulating the self-centering torque generated by the wheels returning to center and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0100] The magnetic powder damper drive module is used to adjust the current of the magnetic powder damper according to the damping torque to generate a corresponding torque, simulating the damping torque between the friction of components in a real transmission system; the corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

[0101] certainly, Figure 4 The architecture shown is merely exemplary; it can be omitted as needed when implementing different functionalities. Figure 4 One or at least two components of the system shown.

[0102] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A force feedback device based on a direct-drive motor and a magnetic powder damper, characterized in that, include: The system comprises a rotary adjustment bracket, a servo motor, an angle sensor, a magnetic powder damper, a steering column, and a PLC. A steering wheel is mounted at the end of the steering column. The servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel are coaxially arranged. The rotary adjustment bracket is fixed to the side wall of the simulated cockpit to simulate the arrangement of the steering wheel transmission structure in a real cockpit and to support the servo motor, angle sensor, magnetic powder damper, steering column, and steering wheel. The servo motor, mounted on the rotary adjustment bracket, generates corresponding torque according to the control commands of the PLC, simulating the self-centering torque generated by the wheels returning to center and the assist torque applied by the power steering motor, and feeds this feedback to the driver through the steering column and the steering wheel mounted on the steering column. The angle sensor is used to detect the steering wheel angle and steering wheel angular velocity and transmit them to the PLC for force feedback simulation calculation; the magnetic powder damper is used to generate damping force under the control of the PLC, simulating the damping torque between the friction of components in a real transmission system, and is fed back to the driver through the steering column and the steering wheel mounted on the steering column; the PLC is used to perform force feedback simulation calculation based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients to obtain the required return torque, assist torque and damping torque, and controls the servo motor to generate return torque and assist torque through the servo driver, and controls the magnetic powder damper to generate damping torque.

2. The force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 1, characterized in that, It also includes a power supply; the power supply is a 220V power supply used to power the servo driver to drive the servo motor; the power supply also outputs a 24V power supply through step-down, used to power the PLC, magnetic powder damper and angle sensor.

3. The force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 1, characterized in that, When performing force feedback simulation, the servo motor adopts torque mode. The PLC sends the sum of the return torque and the assist torque as the target value to the servo driver, thereby controlling the servo motor to generate the target torque. When performing autonomous driving simulation, the servo motor adopts angle mode. The PLC receives the angle value sent by the simulation software and controls the servo driver to control the servo motor to rotate the steering wheel by the corresponding angle according to the corresponding angular velocity.

4. The force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 1, characterized in that, The PLC drives the servo motor to limit the steering wheel's rotation range to ±540°, achieving a soft-limit effect. When the limit value is reached, the servo motor will apply a limiting torque of 10 N·m to prevent the steering wheel from rotating beyond the limit position.

5. The force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 1, characterized in that, The end of the steering column is machined with different types of splines to achieve connection with different steering wheels.

6. The force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 1, characterized in that, The PLC adjusts the input current of the magnetic powder damper to change the shape of the magnetic field inside the damper. The internal magnetic powder will arrange itself along the direction of the magnetic field to form a chain structure. The friction in this process will consume energy, thereby slowing down the vibration and movement of the mechanical system and generating a damping torque.

7. A control method for a force feedback device based on a direct-drive motor and a magnetic powder damper, characterized in that, include: Acquire vehicle speed, steering wheel angle, and steering wheel angular velocity data during simulated driving; The angular acceleration of the steering wheel is calculated by differentiating the angular velocity of the steering wheel. Based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients of the simulated driving, force feedback simulation calculations are performed to obtain the required return torque, assist torque and damping torque; Based on the sum of the self-centering torque and the assist torque, the servo motor is controlled by the servo driver to generate a corresponding torque, simulating the self-centering torque generated by the wheels returning to center and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column. The current of the magnetic powder damper is adjusted according to the damping torque to generate a corresponding torque, simulating the damping torque between the friction of components in a real transmission system. The corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

8. The control method of the force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 7, characterized in that, The corrective torque is calculated using the following formula: T z =K z ·θ+(C z0 +C z1 ·v); Among them, T z For the restoring torque, K z C is the angular coefficient of the restoring torque. z0 C is the offset of the return torque as a function of the velocity value. z1 C is the coefficient of the restoring torque speed. z0 and C z1 All are constants, θ is the steering wheel angle, and V is the vehicle speed data; The assist torque is calculated using the following formula: Among them, T t To assist torque, K t To assist the torque angle coefficient, C t0 To determine the offset of the assist torque gain with speed, C t1 To assist the torque-speed coefficient, C t0 and C t1 All are constants, and b is the transmission ratio. The damping moment is calculated using the following formula: T d =(C d0 +C d1 ·V)·ω; Among them, T d For the damping torque, C d0 C is the offset of the damping torque gain with respect to the velocity value. d1 C is the damping torque velocity coefficient. d0 and C d1 All are constants, and ω is the angular velocity of the steering wheel.

9. The control method of the force feedback device based on a direct-drive motor and a magnetic powder damper according to claim 8, characterized in that, When the vehicle speed is between 0-20 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V, the assist torque angle coefficient is -1.25×10 3 V+0.1; When the vehicle speed data is 20-60km / h, the return torque angle coefficient is 3.75×10. 4 V+7.5×10 3 The assist torque angle coefficient is -6.25×10. 4 V+8.75×10 2 When the vehicle speed is 60-100 km / h, the return torque angle coefficient is 7.5 × 10⁻⁶. 4 V-1.5×10 2 The assist torque angle coefficient is -2.5×10. 3 V+0.2; When the vehicle speed is greater than 100km / h, the return torque angle coefficient is 0.1 and the assist torque angle coefficient is -0.

025.

10. A control system for a force feedback device based on a direct-drive motor and a magnetic powder damper, characterized in that, include: The simulated driving data acquisition module is used to acquire vehicle speed data, steering wheel angle, and steering wheel angular velocity during simulated driving. The steering wheel angular velocity calculation module is used to calculate the angular acceleration of the steering wheel by differentiating the steering wheel angular velocity. The force feedback simulation calculation module is used to perform force feedback simulation calculations based on the vehicle speed data, steering wheel angle, steering wheel angular velocity and preset empirical coefficients of the simulated driving, to obtain the required return torque, assist torque and damping torque; The servo motor drive module is used to control the servo motor to generate a corresponding torque based on the sum of the self-centering torque and the assist torque, thereby simulating the self-centering torque generated by the wheel returning to center and the assist torque applied by the assist motor; the corresponding torque generated by the servo motor is fed back to the driver through the steering column and the steering wheel mounted on the steering column. The magnetic powder damper drive module is used to adjust the current of the magnetic powder damper according to the damping torque, so as to generate a corresponding torque and simulate the damping torque between the friction of components in a real transmission system. The corresponding torque generated by the magnetic powder damper is fed back to the driver through the steering column and the steering wheel mounted on the steering column.

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