Vehicle suspension height and magnetorheological damping cooperative control system and method

Abstract

The application discloses a vehicle suspension height and magnetorheological damping cooperative control system and method, and relates to the field of vehicle suspension height and magnetorheological damping cooperative control system, which comprises a suspension mechanical execution unit, a sensing detection unit and a control unit; the suspension mechanical execution unit comprises an elastic support, a movable spring seat, at least two V-shaped or eight-shaped symmetrically distributed racks, gears corresponding to the racks respectively, a driving device for synchronously driving the gears, a mechanical locking mechanism and a magnetorheological damper; the control unit cooperatively controls the driving device and the magnetorheological damper according to vehicle state information collected by the sensing detection unit, with body height adjustment as a slow variable and damping adjustment as a fast variable; the application can improve the passability, comfort and driving stability of the vehicle, and reduce the complexity of the air or hydraulic height adjustment system.

Description

Technical Field

[0001] This invention relates to the field of vehicle suspension technology, specifically to a vehicle suspension height and magnetorheological damping coordinated control system and method. Background Technology

[0002] With the development of automotive intelligence and chassis integration, vehicle height adjustment and suspension damping adjustment are receiving increasing attention. Vehicle height adjustment can adapt to different loads, road conditions, and parking leveling needs, while suspension damping adjustment directly affects vehicle ride comfort, handling stability, and dynamic attitudes such as pitch and roll. Currently, the technical solutions for achieving adjustable vehicle height can be mainly divided into the following categories.

[0003] One type of solution uses air springs, hydraulic cylinders, or hydropneumatic springs to achieve vehicle height adjustment. Air suspension offers good vibration isolation and comfort, but typically requires an air compressor, air tank, and numerous pneumatic lines, and suffers from issues such as airbag aging, poor low-temperature reliability, slow response, and high cost. Hydraulic or hydropneumatic suspensions have higher load-bearing capacity, but their complex structure, high sealing requirements, susceptibility to leakage, and high maintenance costs all contribute to these problems. All of these solutions use fluid media as elastic or pressure-bearing components, which raises concerns about energy consumption, sealing, and reliability over long-term use.

[0004] Another type is the semi-active suspension solution using magnetorheological dampers. Magnetorheological dampers can adjust damping force in milliseconds by changing the excitation current, offering a fast response and making them suitable for suppressing vehicle vibration, pitch, and roll. However, magnetorheological dampers typically only change damping characteristics and cannot directly change vehicle height, thus making it difficult to meet the needs of vehicle height adjustment for load changes, passability adjustments, and high-speed wind resistance reduction. To address this, some technologies have attempted to combine motor-driven height adjustment mechanisms with magnetorheological dampers. However, the electric height adjustment mechanisms in these solutions often use a single lead screw or rack and pinion structure. Without effective load-bearing components, synchronous guidance, and mechanical locking designs, problems such as uneven load, jamming, reverse drive, the need for continuous power to maintain height adjustment, and unreliable position retention under impact loads can easily occur.

[0005] Therefore, current technology lacks a suspension solution that can organically combine vehicle height adjustment and damping adjustment while maintaining structural simplicity and reliability. On the one hand, it aims to avoid the fluid sealing and continuous pressure issues of air and hydraulic systems, allowing mechanical springs to bear the static load. On the other hand, it aims to reliably maintain the height after adjustment without continuous power consumption, and possess anti-eccentric load and anti-jamming capabilities. Simultaneously, it also aims to quickly adjust damping during dynamic driving to suppress vehicle attitude. Therefore, how to synergistically integrate these functions to achieve unified and reliable control of vehicle height and suspension damping remains a pressing technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] Therefore, the purpose of this invention is to provide a vehicle suspension height and magnetorheological damping coordinated control system and method to solve the problems of existing air suspension, hydraulic suspension and simple magnetorheological suspension in terms of complex structure, high cost, energy consumption for height adjustment, and difficulty in balancing dynamic response and vehicle height adjustment.

[0008] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0009] A vehicle suspension height and magnetorheological damping coordinated control system includes a suspension mechanical actuator, a sensing and detection unit, and a control unit.

[0010] The suspension mechanical actuator includes an elastic support, a movable spring seat, at least two racks symmetrically distributed in a V-shape or figure-eight shape, gears meshing with the racks respectively, a drive device for synchronously driving the gears, a mechanical locking mechanism, and a magnetorheological damper. The elastic support is supported between the movable spring seat and the vehicle body. The drive device drives the racks and the movable spring seat to rise and fall along the suspension axis direction through the gears to adjust the vehicle body height. The mechanical locking mechanism is used to restrict the reverse movement of the movable spring seat after it reaches the target height, so that the movable spring seat maintains the target height after the drive device is powered off. The magnetorheological damper is used to continuously adjust the damping force according to the damping control signal.

[0011] The control unit coordinates the drive device and the magnetorheological damper based on the vehicle status information collected by the sensing and detection unit, using vehicle height adjustment as a slow variable and damping adjustment as a fast variable.

[0012] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, the two racks are arranged in a V-shape, inverted V-shape, figure-eight shape or inverted figure-eight shape relative to the suspension axis.

[0013] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, the drive device includes a geared motor and a synchronous shaft, wherein the synchronous shaft is meshed with the gear.

[0014] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, the mechanical locking mechanism is at least one of a pawl locking mechanism, a wedge locking mechanism, a friction locking mechanism, an electromagnetic pin locking mechanism, or a worm gear self-locking mechanism. The mechanical locking mechanism locks at least one of the rack, gear, or synchronous shaft after the movable spring seat reaches the target height.

[0015] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, the sensing and detection unit includes a height sensor for detecting the height of the four corners of the vehicle body, a vehicle body inertial measurement unit for detecting the vehicle body attitude, and at least one of vehicle speed signal, wheel speed signal, steering angle signal, and braking signal.

[0016] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, the control unit is configured to calculate the average vehicle height, left-right height difference, front-rear height difference, and diagonal height difference based on the signals from the sensing and detection unit, and thereby determine the target height of each suspension.

[0017] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, under conditions of emergency braking, sharp turning, or high-speed driving, the control unit prioritizes adjusting the damping of the magnetorheological damper and limits or delays the height adjustment driven by the drive device.

[0018] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control system described in this invention, in the conditions of parking, low-speed obstacle crossing, load change, or parking leveling, the control unit controls the drive device to drive the rack for height adjustment. Before height adjustment, if the mechanical locking mechanism is in a locked state, the lock is released first before driving the drive device.

[0019] A method for coordinated control of vehicle suspension height and magnetorheological damping includes the following steps:

[0020] S1. The sensing and detection unit collects signals of the vehicle's four corner heights, body posture, and vehicle driving status.

[0021] S2. The control unit calculates the target vehicle height and target damping based on the height of the four corners and the vehicle posture, and identifies the vehicle operating conditions. When the height adjustment conditions are met, the control unit controls the drive device to drive the rack and movable spring seat to adjust the vehicle height.

[0022] S3. During the vehicle's dynamic driving process, the control unit controls the damping of the magnetorheological damper in real time. After the height is adjusted to the correct position, it controls the mechanical locking mechanism to enter the locking state and stops the output of the drive device.

[0023] As a preferred embodiment of the vehicle suspension height and magnetorheological damping coordinated control method of the present invention, it further includes at least one of the following:

[0024] The first item: In step S1, the vehicle status signals include vehicle speed signals, wheel speed signals, steering wheel angle signals, braking signals, acceleration signals, suspension dynamic deflection signals, and road excitation signals. The vehicle operating conditions identified based on these signals include at least parking conditions, low-speed passing conditions, high-speed cruising conditions, turning conditions, braking conditions, acceleration conditions, load change conditions, and road impact conditions.

[0025] The second item: Step S2 includes: determining the target vehicle height by combining the height mode set by the driver, the current vehicle operating conditions and the road surface level. The target vehicle height includes on-demand height adjustment, standard height and automatic load leveling height; and differential height adjustment of the suspension on the left and right sides or front and rear axles during braking, acceleration or turning.

[0026] The third aspect: The method also includes a three-layer control strategy architecture, specifically including: an upper-layer operating condition decision layer, used to identify vehicle operating conditions and output target vehicle height, height adjustment priority, and damping control mode; a middle-layer collaborative control layer, used to balance vehicle posture, driving stability, and ride comfort, coordinate the allocation of height adjustment and damping adjustment amounts, and superimpose safety constraints; and a lower-layer execution control layer, used to perform position closed-loop control on the drive device and excitation current closed-loop control on the magnetorheological damper to execute the target vehicle height and target damping force.

[0027] The fourth item: In step S3, the damping of the magnetorheological damper is controlled in real time, including: calculating the target damping force based on the vertical acceleration of the vehicle body, the vertical acceleration of the wheels and the attitude information of the vehicle body, and adjusting the damping by continuously adjusting or adjusting the excitation current in stages;

[0028] Fifthly, the method also includes coordinated control of height and damping: increasing the damping of the magnetorheological damper during height adjustment to suppress vehicle body oscillation; updating the damping control parameters after height adjustment is completed; prioritizing driving stability when height adjustment conflicts with driving stability control; pausing height adjustment under severe operating conditions and only performing rapid damping adjustment.

[0029] Item 6: During the vehicle height adjustment process, limit the adjustment rate of the movable spring seat and the height difference between the left and right sides of the vehicle, and increase the damping of the magnetorheological damper to avoid sudden changes in vehicle height and oscillations;

[0030] Item 7: The control logic for the vehicle operating conditions includes: under normal driving conditions, maintaining the standard vehicle height and adopting comfort or comprehensive damping mode; under high-speed cruising conditions, lowering the vehicle height and increasing damping to improve handling stability; under rough road conditions, raising the vehicle height and dynamically adjusting damping to balance passability and comfort; under emergency braking conditions, limiting or suspending height adjustment and adjusting front and rear suspension damping to suppress pitch; under acceleration conditions, adjusting suspension damping to suppress front-end lift; under cornering conditions, increasing the outer suspension damping and performing lateral height compensation when necessary to reduce body roll; under load change conditions, adjusting the vehicle height back to the reference height through closed-loop control and simultaneously correcting the damping parameters.

[0031] Item 8: When a sensor malfunction, actuator malfunction, or power supply malfunction is detected, the system enters a safety mode: all height adjustment actions are stopped, the movable spring seat is locked in a safe position, and the magnetorheological damper is switched to a preset safety damping value.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. The static load and main elastic support of the vehicle are borne by the helical spring. Compared with pure electromagnetic bearing or hydraulic or oil-gas continuous pressure bearing solutions, there is no need to continuously consume energy to maintain the load, and there is no risk of fluid sealing and leakage. The structure is simple, the reliability is high, and the cost is lower.

[0034] 2. The load on the movable spring seat can be distributed to the racks on both sides, and in conjunction with the synchronous shaft and gears, synchronous guidance and lifting can be achieved, effectively sharing the lateral force, significantly reducing the risk of off-center load, jamming and reverse drive, and improving the smoothness of movement and load-bearing reliability during the height adjustment process.

[0035] 3. After the target height is adjusted to the correct position, the mechanical locking mechanism restricts the rack from moving in the opposite direction or the synchronous shaft from reversing, so that the movable spring seat can reliably maintain the target height even after the geared motor is powered off. This not only reduces the energy consumption caused by the continuous power supply of the motor, but also improves the position holding capability and failure safety under power failure and impact load.

[0036] 4. Closed-loop coordinated control of vehicle height, pitch, roll and damping is achieved through four-corner height sensors, body IMU and VCU (vehicle controller). Vehicle height adjustment is treated as a slow variable and magnetorheological damping adjustment is treated as a fast variable, which takes into account the vehicle's passability, ride comfort and driving stability, so that the vehicle attitude can be better under different working conditions. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0038] Figure 1 This is a system block diagram of a vehicle suspension height and magnetorheological damping coordinated control system according to the present invention;

[0039] Figure 2 This is a schematic diagram of the suspension mechanical actuator of a vehicle suspension height and magnetorheological damping coordinated control system according to the present invention;

[0040] Figure 3 This is a flowchart illustrating the workflow of a vehicle suspension height and magnetorheological damping coordinated control system according to the present invention. Detailed Implementation

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] See Figure 1 and Figure 2 This invention provides a vehicle suspension height and magnetorheological damping coordinated control system, including a suspension mechanical actuator 100, a sensing and detection unit 200, and a control unit 300. In one specific embodiment, each of the four wheels of the vehicle is provided with an independent suspension mechanical actuator 100, and the four suspension mechanical actuators 100 share the same set of sensing and detection units 200 and control unit 300, thereby realizing independent height adjustment of the four wheels and coordinated control of the vehicle's attitude.

[0043] See Figure 2 The suspension mechanical actuator 100 includes an elastic support 110, a movable spring seat 120, at least two racks 130 symmetrically distributed in a V-shape or figure-eight shape, gears 140 meshing with the racks 130 respectively, a drive device for synchronously driving the gears 140, a mechanical locking mechanism 150, and a magnetorheological damper 160. The elastic support 110 is supported between the movable spring seat 120 and the vehicle body. The drive device drives the racks 130 and the movable spring seat 120 to rise and fall along the suspension axis direction through the gears 140 to adjust the vehicle body height. The mechanical locking mechanism 150 is used to restrict the reverse movement of the movable spring seat 120 after it reaches the target height, so that the movable spring seat 120 maintains the target height after the drive device is powered off. The magnetorheological damper 160 is used to continuously adjust the damping force according to the damping control signal.

[0044] The sensing and detection unit 200 includes a height sensor for detecting the height of the four corners of the vehicle body, a vehicle inertial measurement unit (IMU) for detecting the vehicle body attitude, and at least one of the following from the vehicle CAN bus: vehicle speed signal, wheel speed signal, steering angle signal, and braking signal.

[0045] The control unit 300 is the VCU (Vehicle Control Unit). The VCU controls the geared motor 170 via a motor driver and the excitation coil current of the magnetorheological damper 160 via a magnetorheological current driver. Based on the vehicle status information collected by the sensing unit 200, the control unit 300 coordinates the control of the drive unit and the magnetorheological damper 160, with vehicle height adjustment as a slow variable and damping adjustment as a fast variable. Specifically, height adjustment involves mechanical motion and has a response time on the order of hundreds of milliseconds, so it is executed as a slow variable under suitable operating conditions. Magnetorheological damping adjustment is achieved by changing the excitation current, with a response time on the order of milliseconds, so it is executed in real time as a fast variable during dynamic driving.

[0046] See Figure 2 The two racks 130 are arranged in a V-shape, inverted V-shape, figure-eight shape or inverted figure-eight shape relative to the suspension axis. In one specific embodiment, the upper ends of the two racks 130 are respectively engaged with the movable spring seat 120 in a separable manner, and the lower ends of the two racks 130 are respectively opened to the left and right sides to form an inverted V-shape arrangement. In another embodiment, the two racks 130 can also be arranged in a V-shape with their upper ends open and their lower ends close together. Regardless of the arrangement, the two racks 130 are symmetrically distributed on both sides of the suspension axis, so that the vertical load on the movable spring seat 120 can be decomposed into components along the directions of the two racks 130. When the movable spring seat 120 is subjected to a vertical load from the vehicle body, the load is decomposed through the inclined surfaces of the two racks 130 into a pressure or tension force along the axial direction of the racks 130, and a component perpendicular to the rack surface. Due to the symmetrical arrangement of the two racks, the lateral components perpendicular to the rack surface cancel each other out, thereby effectively reducing the lateral bending stress of a single rack 130 and improving the resistance to eccentric loads and the smoothness of movement. This symmetrical arrangement is particularly suitable for off-road vehicles and engineering vehicles with large load variations and complex road conditions.

[0047] See Figure 2 The drive unit includes a geared motor 170 and a synchronous shaft 180. The output shaft of the geared motor 170 is connected to the synchronous shaft 180 via a coupling or gear transmission, and the synchronous shaft 180 is meshed with gears 140. When the geared motor 170 rotates, it drives the two gears 140 to rotate synchronously through the synchronous shaft 180. The two gears 140 drive the rack 130 to rotate slowly and open, thereby driving the movable spring seat 120 to rise and fall smoothly along the suspension axis.

[0048] The geared motor 170 can be a DC brushed motor, a DC brushless motor, or a stepper motor, and is equipped with a reducer to improve the output torque. The synchronous shaft 180 ensures that the movement of the racks on both sides is strictly synchronized, avoiding jamming, uneven wear, or additional stress caused by asynchronous movement on both sides.

[0049] See Figure 2 The mechanical locking mechanism 150 is located near the rack 130 or the synchronous shaft 180 to restrict the rack 130 from moving in the opposite direction or the synchronous shaft 180 from reversing after the movable spring seat 120 reaches the target height, so that the movable spring seat 120 can reliably maintain the target height after the geared motor 170 is de-energized.

[0050] In one specific embodiment, the mechanical locking mechanism 150 is a ratchet locking mechanism, including a ratchet and a pawl. The ratchet is fixed to the synchronous shaft 180. When the height is adjusted to the correct position, the pawl engages with the tooth groove of the ratchet under the action of spring force, preventing the synchronous shaft 180 from reversing. In another embodiment, the mechanical locking mechanism 150 is a wedge locking mechanism, utilizing the self-locking principle of the inclined surface of the wedge block to achieve unidirectional locking. In yet another embodiment, the mechanical locking mechanism 150 is a friction locking mechanism, limiting the rotation of the synchronous shaft 180 through friction. In yet another embodiment, the mechanical locking mechanism 150 is an electromagnetic pin locking mechanism, controlling the pin to insert into the positioning hole of the rack 130 via an electromagnet. In yet another embodiment, the mechanical locking mechanism 150 is a worm gear self-locking mechanism, utilizing the self-locking characteristics of worm gear transmission to achieve power-off retention. The above types of locking mechanisms can be used individually or in combination. Those skilled in the art can select the appropriate locking method according to actual needs.

[0051] The mechanical locking mechanism 150 can be locked on at least one of the rack 130, gear 140, or synchronous shaft 160. For example, when a ratchet and pawl are provided on the synchronous shaft 160, the locking action directly restricts the reverse rotation of the synchronous shaft 160; when a positioning hole and a pin are provided on the rack 130, the locking action directly restricts the linear movement of the rack. Regardless of the locking point, the effect is to prevent the movable spring seat 120 from moving in the reverse direction after reaching the height, thereby achieving power-off retention.

[0052] The sensing and detection unit 200 includes height sensors, a vehicle IMU (Integrated Measurement Unit), and vehicle CAN bus signals. The height sensors are located at the four corners of the vehicle body to detect the vehicle height at each wheel; these sensors can be displacement sensors, ultrasonic sensors, Hall effect sensors, or photoelectric sensors. The vehicle IMU is mounted near the vehicle's center of gravity to detect attitude information such as pitch angle, roll angle, vertical acceleration, pitch rate, and roll rate. Furthermore, the control unit 300 acquires vehicle speed signals, wheel speed signals, steering angle signals, and braking signals via the CAN bus; these signals are used for operating condition identification and the execution of cooperative control strategies.

[0053] The control unit 300 is configured to calculate the average vehicle height, left-right height difference, front-rear height difference, and diagonal height difference based on signals from the sensor detection unit. The control unit 300 then determines the target height for each suspension based on these height difference calculations. For example, if the left-right height difference exceeds a preset threshold, it indicates vehicle roll or uneven load distribution. The control unit will adjust the target heights of the left front, right front, left rear, and right rear suspensions accordingly to restore the vehicle to a level position. If a diagonal height is detected as too low, such as an increased load on the right rear wheel, the control unit can independently raise the suspension height at that location. This four-corner independent adjustment capability allows the vehicle to adapt to complex load distributions and road conditions.

[0054] See Figure 3 The present invention also provides a method for coordinated control of vehicle suspension height and magnetorheological damping, the method comprising the following steps:

[0055] Step S1: The sensing and detection unit 200 collects vehicle four-corner height, vehicle attitude pitch angle, roll angle, vertical acceleration, and vehicle driving status signals such as vehicle speed, wheel speed, steering angle, and braking signal. These signals are transmitted to the control unit 300 via CAN bus or hardwired connection.

[0056] Step S2: The control unit 300 calculates the target vehicle height and target damping based on the height at the four corners and the vehicle's attitude, and determines the final target vehicle height by combining the height mode set by the driver, the current vehicle operating conditions, and the road surface grade. The target vehicle height includes on-demand height adjustment, standard height, and automatic load leveling height. During braking, acceleration, or turning, differential height adjustment is also performed on the suspensions on the left and right sides of the vehicle or the front and rear axles. At the same time, the control unit 300 identifies whether the current operating condition is a parking, low-speed passage, high-speed cruising, turning, braking, acceleration, load change, or road impact condition based on vehicle speed signals, wheel speed signals, steering wheel angle signals, braking signals, acceleration signals, suspension dynamic deflection signals, and road excitation signals.

[0057] Step S3: When the height adjustment conditions are met, the control unit 300 controls the drive device to drive the rack 130 and the movable spring seat 120 to adjust the vehicle height. The height adjustment conditions are: the vehicle speed is lower than a preset threshold, and the amount by which the vehicle height deviates from the target value exceeds the dead zone range. Before adjustment, if the mechanical locking mechanism 150 is in a locked state, the lock is first released, and the reduction motor 170 drives the gears 140 on both sides to rotate synchronously via the synchronous shaft 180, driving the V-shaped rack 130 and the movable spring seat 120 to rise and fall smoothly. During the adjustment process, the control unit 300 limits the adjustment rate of the movable spring seat 120 and the height difference between the left and right sides of the vehicle, and increases the damping of the magnetorheological damper 160 to avoid sudden changes and oscillations in vehicle height.

[0058] Step S4: During vehicle dynamic driving, the control unit 300 controls the damping of the magnetorheological damper 160 in real time. This step is executed as a fast variable in each control cycle and is not limited by height adjustment conditions. The control unit 300 calculates the target damping force based on the vehicle body vertical acceleration, wheel vertical acceleration, and vehicle attitude information, and adjusts the damping in real time by continuously adjusting or stepwise adjusting the excitation current.

[0059] Step S5: During the height adjustment process, the control unit 300 increases the damping of the magnetorheological damper 160 to suppress vehicle body oscillation; after the height adjustment is completed, the control unit 300 updates the damping control parameters; when the height adjustment conflicts with the driving stability control, the control unit 300 prioritizes driving stability; under severe operating conditions, the control unit 300 suspends the height adjustment and only performs rapid adjustment of the damping.

[0060] Step S6: After the height adjustment is complete, the control unit 300 controls the mechanical locking mechanism 150 to enter the locking state and stops the drive device output. Specifically, after the height sensor confirms that the movable spring seat 120 or the vehicle body height has reached the target range and stabilized for a preset time, the control unit 300 triggers the mechanical locking mechanism 150 to perform the locking action, and then stops the output of the reduction motor 170 through the motor driver. Afterwards, even if the reduction motor 170 is de-energized, the movable spring seat 120 can still be mechanically locked at the target height.

[0061] Step S7: When the control unit 300 detects a sensor malfunction, actuator malfunction, or power supply malfunction, the system enters a safety mode: all height adjustment actions are stopped, the movable spring seat 120 is locked in the current safe position, and the magnetorheological damper 160 is switched to the preset safety damping value to ensure that the vehicle can continue to drive in a basically safe posture.

[0062] Furthermore, the control strategy of the present invention adopts a three-layer architecture to achieve orderly coordination between height adjustment and damping adjustment.

[0063] Upper-level operating condition decision layer: Used to identify the current vehicle operating condition and output the target vehicle height, height adjustment priority, and damping control mode, providing a decision basis for the lower-level control.

[0064] The middle layer of the coordinated control layer is used to balance vehicle posture, driving stability and ride comfort, coordinate the allocation of height adjustment and damping adjustment, and superimpose safety constraints during the allocation process to avoid conflicts between height adjustment and stability control.

[0065] The bottom-level execution control layer is used to perform closed-loop position control on the drive device to accurately execute the target vehicle height; and to perform closed-loop excitation current control on the magnetorheological damper 160 to accurately execute the target damping force.

[0066] Specifically, the collaborative control logic under different vehicle operating conditions is as follows:

[0067] When the vehicle is driving normally, maintain the standard vehicle height and use comfort mode or combined mode damping; when the vehicle is cruising at high speed, lower the vehicle height, increase damping, and improve handling stability; when the vehicle is driving on rough roads, raise the vehicle height and dynamically adjust damping to balance passability and comfort; when the vehicle brakes suddenly, limit or suspend height adjustment and adjust the front and rear suspension damping to suppress pitch; when the vehicle is accelerating, maintain the current height and adjust the suspension damping to suppress front lift; when the vehicle is turning, perform left and right height compensation, increase the damping of the outer suspension, and reduce body roll; when the vehicle load changes, adjust back to the reference height through closed-loop control and simultaneously correct the damping parameters; when the vehicle is raising or lowering, limit the adjustment rate and left and right height difference, and increase damping to avoid sudden changes and oscillations in the vehicle body.

[0068] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A vehicle suspension height and magnetorheological damping coordinated control system, characterized in that, It includes a suspension mechanical actuator (100), a sensing and detection unit (200), and a control unit (300). The suspension mechanical actuator (100) includes an elastic support (110), a movable spring seat (120), at least two racks (130) symmetrically distributed in a V-shape or figure-eight shape, gears (140) respectively meshing with the racks (130), a drive device for synchronously driving the gears (140), a mechanical locking mechanism (150), and a magnetorheological damper (160); the elastic support (110) is supported between the movable spring seat (120) and the vehicle body. The drive device drives the rack (130) and the movable spring seat (120) to rise and fall along the suspension axis direction via the gear (140) to adjust the vehicle height. The mechanical locking mechanism (150) is used to restrict the reverse movement of the movable spring seat (120) after it reaches the target height, so that the movable spring seat (120) maintains the target height after the drive device is powered off. The magnetorheological damper (160) is used to continuously adjust the damping force according to the damping control signal. The control unit (300) coordinates the drive device and the magnetorheological damper (160) based on the vehicle status information collected by the sensing and detection unit (200), with vehicle height adjustment as a slow variable and damping adjustment as a fast variable.

2. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 1, characterized in that, The two racks (130) are arranged in a V-shape, inverted V-shape, figure-eight shape or inverted figure-eight shape relative to the suspension axis.

3. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 2, characterized in that, The drive device includes a geared motor (170) and a synchronous shaft (180), the synchronous shaft (180) being meshed with the gear (140).

4. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 3, characterized in that, The mechanical locking mechanism (150) is at least one of a pawl locking mechanism, a wedge locking mechanism, a friction locking mechanism, an electromagnetic pin locking mechanism, or a worm gear self-locking mechanism. The mechanical locking mechanism (150) locks at least one of the rack (130), gear (140), or synchronous shaft (180) after the movable spring seat (120) reaches the target height.

5. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 1, characterized in that, The sensing and detection unit (200) includes a height sensor for detecting the height of the four corners of the vehicle body, a vehicle body inertial measurement unit for detecting the vehicle body attitude, and at least one of vehicle speed signal, wheel speed signal, steering angle signal, and braking signal.

6. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 1, characterized in that, The control unit (300) is configured to calculate the average height of the vehicle body, the left-right height difference, the front-rear height difference, and the diagonal height difference based on the signals from the sensing unit (200), and thereby determine the target height of each suspension.

7. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 1, characterized in that, In the event of emergency braking, sharp turns, or high-speed driving, the control unit (300) prioritizes adjusting the damping of the magnetorheological damper (160) and limits or delays the height adjustment driven by the drive device.

8. The vehicle suspension height and magnetorheological damping coordinated control system according to claim 1, characterized in that, When the vehicle is parked, passing through obstacles at low speed, experiencing load changes, or leveling while parked, the control unit (300) controls the drive device to drive the rack (130) for height adjustment. Before height adjustment, if the mechanical locking mechanism (150) is in a locked state, the lock is released first before driving the drive device.

9. A method for coordinated control of vehicle suspension height and magnetorheological damping, applied to a coordinated control system for vehicle suspension height and magnetorheological damping as described in any one of claims 1-8, characterized in that, Includes the following steps: S1, The sensing and detection unit (200) collects signals of vehicle height at four corners, vehicle body posture and vehicle driving status; S2. The control unit (300) calculates the target vehicle height and target damping based on the height of the four corners and the vehicle posture, and identifies the vehicle operating conditions. When the height adjustment conditions are met, the control unit drives the rack (130) and the movable spring seat (120) to adjust the vehicle height. S3. During the dynamic driving process of the vehicle, the control unit (300) controls the damping of the magnetorheological damper (160) in real time. After the height is adjusted to the correct position, it controls the mechanical locking mechanism (150) to enter the locking state and stops the output of the drive device.

10. The method for coordinated control of vehicle suspension height and magnetorheological damping according to claim 9, characterized in that, It also includes at least one of the following: The first item: In step S1, the vehicle status signals include vehicle speed signals, wheel speed signals, steering wheel angle signals, braking signals, acceleration signals, suspension dynamic deflection signals, and road excitation signals. The vehicle operating conditions identified based on these signals include at least parking conditions, low-speed passing conditions, high-speed cruising conditions, turning conditions, braking conditions, acceleration conditions, load change conditions, and road impact conditions. The second item: Step S2 includes: determining the target vehicle height by combining the height mode set by the driver, the current vehicle operating conditions and the road surface level. The target vehicle height includes on-demand height adjustment, standard height and automatic load leveling height; and differential height adjustment of the suspension on the left and right sides or front and rear axles during braking, acceleration or turning. The third item: The method also includes a three-layer control strategy architecture, specifically including: an upper working condition decision layer, used to identify vehicle working conditions and output target vehicle height, height adjustment priority and damping control mode; a middle collaborative control layer, used to take into account vehicle posture, driving stability and ride comfort, coordinate the allocation of height adjustment amount and damping adjustment amount, and superimpose safety constraints; and a bottom execution control layer, used to perform position closed-loop control on the drive device and excitation current closed-loop control on the magnetorheological damper (160) to execute the target vehicle height and target damping force. Fourth item: In step S3, the damping of the magnetorheological damper (160) is controlled in real time, including: calculating the target damping force based on the vertical acceleration of the vehicle body, the vertical acceleration of the wheel and the attitude information of the vehicle body, and adjusting the damping by continuously adjusting or adjusting the excitation current in stages. Fifthly: The method also includes coordinated control of height and damping: increasing the damping of the magnetorheological damper (160) during height adjustment to suppress vehicle body oscillation; updating the damping control parameters after height adjustment is completed; prioritizing driving stability when height adjustment conflicts with driving stability control; pausing height adjustment under severe operating conditions and only performing rapid damping adjustment. Item 6: During the vehicle height adjustment process, the adjustment rate of the movable spring seat (120) and the height difference between the left and right sides of the vehicle body are limited, and the damping of the magnetorheological damper (160) is increased to avoid sudden changes in vehicle height and oscillations; Item 7: The control logic for the vehicle operating conditions includes: under normal driving conditions, maintaining the standard vehicle height and adopting comfort or comprehensive damping mode; under high-speed cruising conditions, lowering the vehicle height and increasing damping to improve handling stability; under rough road conditions, raising the vehicle height and dynamically adjusting damping to balance passability and comfort; under emergency braking conditions, limiting or suspending height adjustment and adjusting front and rear suspension damping to suppress pitch; under acceleration conditions, adjusting suspension damping to suppress front-end lift; under cornering conditions, increasing the outer suspension damping and performing lateral height compensation when necessary to reduce body roll; under load change conditions, adjusting the vehicle height back to the reference height through closed-loop control and simultaneously correcting the damping parameters. Item 8: When a sensor malfunction, actuator malfunction, or power supply malfunction is detected, the system enters a safety mode: all height adjustment actions are stopped, the movable spring seat (120) is locked in a safe position, and the magnetorheological damper (160) is switched to a preset safety damping value.

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