Control method and control system for hydraulic suspension with stepless, rapid and real-time adjustable rigidity

Abstract

The invention discloses a hydraulic suspension control method and control system with stepless, rapid and real-time adjustable rigidity, the suspension system receives vehicle information in real time and adjusts the rigidity of a suspension according to the received information, including adjusting the rigidity of the suspension according to the received vehicle roll / pitch angle information or roll / pitch angular velocity information or vertical acceleration information, and adjusting the rigidity of the suspension according to the received vehicle roll / pitch angle information or roll / pitch angular velocity information or vertical acceleration information. According to the received information and the action areas of the rodless cavity and the rod cavity of the shock absorber, the pressure variation required by the rod cavity and the rodless cavity of the shock absorber and the target pressure value of the required rigidity are solved; according to the target pressure value and the pressure variation, the oil pressure of the rod cavity and the oil pressure of the rodless cavity are rapidly adjusted to the target value by controlling the power of a control motor of the oil way and / or the opening degree of a valve, and the rigidity of the suspension is rapidly adjusted to the required rigidity value. According to the method, the oil supply pressure in the shock absorber is adjusted in real time according to the target value and the actual value of the pressure of the shock absorber, so that the pressure value in the shock absorber reaches the required value, and the real-time rapid stepless adjustment of the rigidity is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle suspension systems, and in particular to a hydraulic suspension control method and control system with stepless, rapid and real-time adjustable stiffness. Background Art

[0002] The suspension system is a crucial component of a vehicle, crucially impacting its ride smoothness and handling stability. It elastically connects the vehicle body and wheels, transferring forces and torques between them and continuously absorbing shocks and vibrations during driving.

[0003] There are two main ways to adjust suspension stiffness in automotive suspension systems: one is an air suspension system with air springs, where stiffness is adjusted by adjusting the gas volume inside the air springs. This method is not only costly but also slow to change stiffness, has a long response time, and is inefficient. The other is a hydraulic suspension system with oil-gas springs (such as accumulators), where stiffness is provided by the accumulator. Because the effective volume of the accumulator becomes a fixed value after manufacturing and cannot be changed, the stiffness of a single accumulator is generally not adjustable. To achieve stiffness adjustment, different numbers of accumulators can be connected to achieve different stiffness adjustments. This method can only achieve multi-level adjustment based on the number of accumulators connected, but cannot achieve stepless stiffness adjustment. These two methods are not very effective in improving vehicle comfort.

[0004] At present, the fully hydraulic active suspension system can achieve rapid and stepless adjustment of damping by controlling the opening of the valve connecting the upper and lower chambers of the shock absorber. However, the effect of rapid and stepless adjustment of damping is limited, the adjustable range is small, and the improvement of vehicle comfort is not enough.

[0005] In the current automobile suspension system, there is no effective solution to achieve stepless, rapid and real-time adjustment of shock absorber stiffness, and the effect of improving vehicle comfort is not good enough. Summary of the Invention

[0006] In order to address the shortcomings of current automobile suspension systems in improving vehicle comfort, the applicant provides a hydraulic suspension control method and control system with a rational structure and stepless, rapid and real-time adjustable stiffness. By adjusting the oil supply pressure in the shock absorber in real time, the stiffness can be adjusted in real time and rapidly, thereby improving the comfort of the vehicle.

[0007] The technical solutions adopted in the present invention are as follows: A hydraulic suspension control method with stepless, fast, and real-time adjustable stiffness, wherein the suspension system receives vehicle information in real time and adjusts the stiffness of the suspension according to the received information, at least comprising: Calculating a target value of a total roll / pitch moment or a total vertical force required for a required suspension stiffness based on the received vehicle roll / pitch angle information, roll / pitch angular velocity information, or vertical acceleration information; Distribute the total roll / pitch moment or total vertical force to each wheel according to vehicle speed, vertical acceleration, or roll / pitch angle, and convert the moment into force to obtain the vertical force / roll force / pitch force of each wheel; Based on the effective area of ​​the rodless cavity and the rodless cavity of the wheel shock absorber, as well as the vertical force / roll force / pitch force, the required pressure change of the rodless cavity and the rodless cavity of the shock absorber, and the target pressure value of the required stiffness are calculated; based on the target pressure value and the pressure change, the oil pressure of the rod cavity and the rodless cavity is quickly adjusted to the target value by controlling the power of the control motor of the oil circuit and / or the opening of the valve, so that the suspension stiffness is quickly adjusted to the required stiffness value.

[0008] As a further improvement of the above technical solution: During the stiffness adjustment process, the pressure change rates of the rod chamber and the rodless chamber of the shock absorber maintain the same proportional change; when the difference in the change rates of the two exceeds a certain threshold, the suspension controller increases the power of the motor with a slower change rate or reduces the speed of the motor with a faster change rate, or the suspension controller increases the opening of the proportional valve with a slower change rate or reduces the opening of the proportional valve with a faster change rate.

[0009] Control valves are respectively provided on the oil circuits of the rod chamber and the rodless chamber of the shock absorber; when the stiffness increases, the oil flow direction of the control valve flows from the oil tank to the shock absorber; when the stiffness decreases, the oil flow direction of the control valve flows from the shock absorber to the oil tank. After the stiffness reaches the target value, the control valve switches the flow direction.

[0010] When distributing the total roll / pitch moment or total vertical force, the total roll / pitch moment or total vertical force is first distributed to the front and rear axles based on the vehicle speed information to obtain the front axle roll / pitch moment or vertical force and the rear axle roll / pitch moment or vertical force. Then, based on the vehicle speed and vertical acceleration or the roll / pitch angle, the front axle roll / pitch moment or vertical force is distributed to the two front wheels, and the rear axle roll / pitch moment or vertical force is distributed to the two rear wheels. Based on the wheelbase or the distance from the center of mass to the front and rear axles, the roll / pitch moment of each wheel is converted into a roll / pitch force to obtain the vertical force / roll force / pitch force of each wheel.

[0011] The distribution ratio of the front and rear axles is different at different vehicle speeds; at low speeds, the distribution ratio of the front axle is higher than that of the rear axle; at high speeds, the distribution ratio of the front axle is lower than that of the rear axle; in the medium speed range, the distribution ratio of the front and rear axles is almost equal.

[0012] When rolling, the torque distributed to the outer wheel is high and the torque distributed to the inner wheel is small; the larger the roll angle and the higher the vehicle speed, the higher the torque gain of the outer wheel.

[0013] A hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness is controlled by the above-mentioned control method, and includes a shock absorption control module, a suspension controller, an inertial measurement unit, a chassis domain control module, and an operating mode module. A shock absorption control module is provided for each wheel of the vehicle, and the shock absorption control module, the inertial measurement unit, the chassis domain control module, and the operating mode module are respectively connected to the suspension controller. The shock absorption control module provides the suspension controller with pressure value information of the pressure sensor, the inertial measurement unit provides the suspension controller with roll / pitch inclination, roll / pitch angular velocity, and vertical acceleration information, the chassis domain control module provides the suspension controller with vehicle speed information, and the operating mode module provides the suspension controller with vehicle operating mode information; an oil tank and a shock absorber are provided on the shock absorption control module, the rodless cavity of the shock absorber is connected to the oil tank via a lower cavity oil circuit, and the rod cavity is connected to the oil tank via an upper cavity oil circuit.

[0014] As a further improvement of the above technical solution: The lower chamber oil circuit and the upper chamber oil circuit are independently connected to the oil tank. The lower chamber oil circuit and the upper chamber oil circuit are respectively provided with an oil pump, a control valve and an energy accumulator. The oil pump is connected to the control motor. A pressure sensor is provided between the energy accumulator and the oil chamber of the shock absorber. The control motor, the control valve and the pressure sensor are connected to the suspension controller.

[0015] The lower chamber oil circuit and the upper chamber oil circuit are merged into the main oil circuit and connected to the oil tank through the main oil circuit; a main oil pump is provided on the main oil circuit, and the main oil pump is connected to the main control motor ME; the lower chamber oil circuit and the upper chamber oil circuit are respectively provided with a control valve, an energy accumulator, and a proportional valve, and a pressure sensor is provided between the energy accumulator and the oil chamber of the shock absorber, and the main control motor ME, the control valve, the proportional valve, and the pressure sensor are connected to the suspension controller.

[0016] One-way valves are respectively provided on the lower chamber oil circuit and the upper chamber oil circuit, and the one-way valves are provided between the oil pump or the proportional valve and the control valve.

[0017] The beneficial effects of the present invention are as follows: The present invention calculates the vertical force or roll / pitch moment required for real-time stiffness based on the vehicle's vertical acceleration or roll / pitch angle or angular velocity, and distributes it according to the vehicle speed. The target value of the pressure required for stiffness is calculated based on the distributed value and the actual pressure values ​​of the sensors of the rod chamber and rodless chamber of the shock absorber. The power of the motor and / or the opening or switch of the valve are controlled according to the target value and the actual value, and the oil supply pressure in the shock absorber is adjusted in real time to make the pressure value in the shock absorber reach the required value, thereby realizing real-time, rapid and stepless adjustment of stiffness.

[0018] This invention enables real-time, rapid, and stepless adjustment of vehicle stiffness during operation, significantly improving vehicle comfort and stability. This real-time, rapid, and stepless adjustment of stiffness allows for a wider adjustment range, further enhancing vehicle comfort. Furthermore, in the event of vibration or impact during operation, this real-time, rapid, and stepless adjustment of stiffness allows for timely adjustment of the stiffness value, protecting the vehicle and providing further advantages for enhancing vehicle safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the system architecture of the first embodiment of the present invention.

[0020] Figure 2 Schematic diagram of the system architecture of the second embodiment of the present invention.

[0021] Figure 3 Schematic diagram of the control flow of the present invention.

[0022] In the figure: 100, shock absorption control module; 1, oil tank; 2, shock absorber; 21, rodless chamber; 22, rod chamber; 3, lower chamber oil pump; 31, lower chamber oil pump overflow valve; 4, lower chamber check valve; 5, lower chamber accumulator; 6, upper chamber oil pump; 61, upper chamber oil pump overflow valve; 7, upper chamber check valve; 8, upper chamber accumulator; ME1, lower chamber control motor; ME2, upper chamber control motor; 1YA, lower chamber control valve; 2YA, upper chamber control valve; P3, upper chamber pressure sensor; P4, lower chamber pressure sensor; ME, main control motor; 9, main oil pump; 91, main oil pump overflow valve; 3YA, lower chamber proportional valve; 4YA, upper chamber proportional valve; 10. Lower chamber oil circuit; 20. Upper chamber oil circuit; 30. Main oil circuit; 200, suspension controller; 300, inertial measurement unit; 400, chassis domain control module; 500, operation mode module. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0024] The present invention provides a hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness, aiming to achieve stepless, rapid and real-time adjustment of stiffness, improve vehicle comfort, and enhance vehicle stability and safety.

[0025] Example 1 of the control system like Figure 1As shown, the hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness provided by the present invention includes a shock absorption control module 100, a suspension controller 200, an inertial measurement unit 300, a chassis domain control module 400, and an operating mode module 500. A shock absorption control module 100 is provided for each wheel of the vehicle. The shock absorption control module 100, the inertial measurement unit 300, the chassis domain control module 400, and the operating mode module 500 are respectively connected to the suspension controller 200. The shock absorption control module 100 provides the suspension controller 200 with the pressure value information of the pressure sensor, and the inertial measurement unit 300 provides the suspension controller 200 with information such as roll / pitch angle, roll / pitch angular velocity, and vertical acceleration. The chassis domain control module 400 provides the suspension controller 200 with the vehicle speed information, and the operating mode module 500 provides the suspension controller 200 with the vehicle operating mode information. The suspension controller 200 calculates the pressure target value information of the shock absorption control module 100 for each wheel based on the received information, and controls the shock absorption control module 100 to adjust the stiffness based on the pressure target value information so that its pressure value reaches the target value.

[0026] Each damping control module 100 includes an oil tank 1 and a shock absorber 2 connected to a wheel. The shock absorber 2 includes a rodless chamber 21 and a rod chamber 22. The rodless chamber 21 is connected to the oil tank 1 via a lower chamber oil passage 10, while the rod chamber 22 is connected to the oil tank 1 via an upper chamber oil passage 20.

[0027] On the lower chamber oil circuit 10, a lower chamber oil pump 3, a lower chamber one-way valve 4, a lower chamber control valve 1YA, and a lower chamber accumulator 5 are sequentially arranged along the direction from the oil tank 1 to the rodless chamber 21. The lower chamber oil pump 3 is connected to the lower chamber control motor ME1 and is controlled by the lower chamber control motor ME1. The suspension controller 200 controls the oil flow in and out of the rodless chamber 21 of the shock absorber 2 by controlling the power of the control motor ME1. The oil in the lower chamber oil circuit 10 can flow back to the oil tank 1 through the overflow circuit. A lower chamber pressure sensor P4 is arranged between the lower chamber accumulator 5 and the rodless chamber 21. The lower chamber pressure sensor P4 is used to monitor the real-time pressure value of the rodless chamber 21 and provide the pressure value to the suspension controller 200 as one of the adjustment bases of the shock absorber 2.

[0028] An upper chamber oil pump 6, an upper chamber check valve 7, an upper chamber control valve 2YA, and an upper chamber accumulator 8 are sequentially arranged along the upper chamber oil circuit 20 from the oil tank 1 to the rod chamber 22. The upper chamber oil pump 6 is connected to and controlled by the upper chamber control motor ME2. The suspension controller 200 controls the flow of oil in and out of the rod chamber 22 of the shock absorber 2 by controlling the power of the control motor ME2. The upper chamber oil pump overflow valve 61 is connected to the oil tank 1 via an overflow circuit, allowing the oil in the upper chamber oil circuit 20 to flow back to the oil tank 1 through the overflow circuit. An upper chamber pressure sensor P3 is arranged between the upper chamber accumulator 8 and the rod chamber 22. The upper chamber pressure sensor P3 is used to monitor the real-time pressure value of the rod chamber 22 and provide the pressure value to the suspension controller 200 as one of the adjustment bases for the shock absorber 2.

[0029] Example 2 of the control system like Figure 2 As shown, different from the first embodiment, the lower chamber oil circuit 10 and the upper chamber oil circuit 20 of each shock absorption control module 100 of this embodiment are not connected to the oil tank 1 separately, but are collected into the main oil circuit 30 and then connected to the oil tank 1 through the main oil circuit 30; the oil pump and the oil pump overflow valve are no longer provided on the lower chamber oil circuit 10 and the upper chamber oil circuit 20, but a main oil pump 9 and a main oil pump overflow valve 91 are provided on the main oil circuit 30, and the main oil pump 9 is connected to the main control motor ME.

[0030] In this embodiment, a lower chamber proportional valve 3YA is provided in the lower chamber oil circuit 10 between the connection point of the main oil circuit 30 and the lower chamber check valve 4. By controlling the opening of the lower chamber proportional valve 3YA, the oil flow in and out of the rodless chamber 21 of the shock absorber 2 is controlled. In the upper chamber oil circuit 20, an upper chamber proportional valve 4YA is provided between the connection point of the main oil circuit 30 and the upper chamber check valve 7. By controlling the opening of the upper chamber proportional valve 4YA, the oil flow in and out of the rod chamber 22 of the shock absorber 2 is controlled.

[0031] like Figure 3 As shown, the suspension controller 200 of the hydraulic suspension control system receives in real time the roll / pitch angle or roll / pitch angular velocity or vertical acceleration information transmitted by the IMU sensor of the inertial measurement unit 300, the vehicle speed information transmitted by the chassis domain control module 400, the vehicle operation mode information transmitted by the operation mode module 500, and the pressure information of the upper cavity pressure sensor P3 and the lower cavity pressure sensor P4 transmitted by the shock absorption control module 100. The suspension controller 200 quickly adjusts the stiffness of the suspension in real time according to the received information. The specific control process is as follows: S1. Based on the received vehicle roll / pitch angle or roll / pitch angular velocity or vertical acceleration, determine a target value of the total roll / pitch moment or total vertical force required for real-time control of the required suspension stiffness in this state, for real-time adjustment of the suspension stiffness.

[0032] S2. Based on the received vehicle speed information, the total roll / pitch moment or total vertical force is distributed to the front and rear axles. The distribution ratios of the front and rear axles vary depending on the vehicle speed: at low speeds, the distribution ratio to the front axle is higher than that to the rear axle; at high speeds, the distribution ratio to the front axle is lower than that to the rear axle; at medium speeds, the distribution ratios to the front and rear axles are approximately equal, i.e., the total roll / pitch moment or total vertical force is evenly distributed between the front and rear axles. Take vehicle roll as an example: at low speed (for example, vehicle speed ≤ 30km / h), the roll acceleration is large but the inertia is small, and the steering response is sensitive. The front axle is allocated 65% to 75%, and the rear axle is allocated 25% to 35%. Through such a proportional distribution, the "nodding roll" of the vehicle body during steering can be quickly suppressed, and the steering accuracy can be improved; at high speed (for example, vehicle speed ≥ 80km / h), the roll inertia is large and the centrifugal force continues to act strongly. The front axle is allocated 35% to 45%, and the rear axle is allocated 55% to 65%. Through such a proportional distribution, the overall roll of the vehicle body can be balanced, "tail slip" can be prevented, and high-speed stability can be maintained; in the medium speed range (30-80km / h), the roll characteristics are between the two, and the front and rear axle distribution ratio is close to 50:50. Through such a distribution, both steering response and vehicle stability are taken into account.

[0033] S3. Based on vehicle speed and vertical acceleration or roll / pitch angle, the front axle roll / pitch moment or vertical force is distributed to the two front wheels, and the rear axle roll / pitch moment or vertical force is distributed to the two rear wheels. Based on the wheelbase or the distance from the center of mass to the front and rear axles, the roll / pitch moment of each wheel is converted into roll / pitch force to obtain the vertical force / roll / pitch force of each wheel. Take roll as an example: when rolling, the torque distributed to the outer wheel is high and the torque distributed to the inner wheel is low; the distribution of four-wheel torque is based on the load and dynamic balance of the roll state; when rolling, the load change formula of the inner and outer wheels is ΔF = h*m*a y / B, where h is the height of the center of mass, m is the mass of the vehicle, and a y is the lateral acceleration, and B is the wheelbase; for example, when the vehicle's roll angle is 3°, the load on the outer wheel can be increased by 15% to 20%, while the load on the inner wheel is reduced by the same proportion accordingly; the key adjustment factors are the roll angle and vehicle speed. The larger the roll angle, the higher the torque gain of the outer wheel, and the higher the vehicle speed, the higher the torque gain of the outer wheel; at low speeds, the front axle takes the lead to enhance steering response. For example, when cornering at low speed, the torque of the outer wheel of the front axle is 20% to 30% higher than that of the inner wheel of the front axle to generate a yaw torque to assist steering and reduce understeer; at high speeds, the rear axle takes the lead to stabilize the vehicle body posture. For example, when changing lanes at high speed, the torque of the outer wheel of the rear axle is 25% to 30% higher than that of the inner wheel of the rear axle to offset the rear slip caused by centrifugal force and improve stability.

[0034] S4, according to the effective area of ​​the rodless cavity 21 and the rodless cavity 22 of the shock absorber 2 of each wheel, and the vertical force / rolling force / pitching force of each wheel, according to ΔP=F / A, calculate the pressure increments ΔP31 and ΔP41 required for the rod cavity 22 and the rodless cavity 21 of the shock absorber 2, and then calculate the actual pressure values ​​P3 of the rod cavity 22 and the rodless cavity 21 transmitted by the upper cavity pressure sensor P3 and the lower cavity pressure sensor P4 at the current time. actual1 and P4 actual1 , calculate the pressure value (i.e. target pressure value) P3 required for the current moment of demand stiffness desire1 =P3 actual1 +ΔP31, P4 desire1 =P4 actual1 +ΔP41.

[0035] For the control system of embodiment 1, according to P3 desire1 And the real-time pressure value P3 measured by the upper chamber pressure sensor P3 actual The difference between the upper chamber and the motor ME2 controls the power (speed and torque) according to P4. desire1 And the real-time pressure value P4 measured by the lower chamber pressure sensor P4 actual The difference between the two controls the power (speed and torque) of the lower chamber control motor ME1, so that the actual pressure of the rod chamber 22 and the rodless chamber 21 (upper chamber pressure sensor P3 and lower chamber pressure sensor P4) can quickly and stably reach the target value P3. desire1 and P4 desire1 , so that the suspension stiffness can be adjusted quickly and stably to the stiffness value required in this state.

[0036] For the control system of the second embodiment, according to P3 desire1 And the real-time pressure value P3 measured by the upper chamber pressure sensor P3 actual The difference between the upper chamber proportional valve 4YA and the lower chamber proportional valve 4YA controls the opening of the upper chamber proportional valve 4YA. desire1 And the real-time pressure value P4 measured by the lower chamber pressure sensor P4 actual The difference between the two controls the opening of the lower chamber proportional valve 3YA and the power (speed and torque) of the total control motor ME, so that the actual pressure of the rod chamber 22 and the rodless chamber 21 (upper chamber pressure sensor P3 and lower chamber pressure sensor P4) can quickly and stably reach the target value P3. desire1 and P4 desire1 , so that the suspension stiffness can be adjusted quickly and stably to the stiffness value required in this state.

[0037] In step S4, in order to ensure that the vehicle body height remains unchanged, the pressure change rates of the rod chamber 22 and the rodless chamber 21 (upper chamber pressure sensor P3 and lower chamber pressure sensor P4) must maintain the same proportional change. When the difference in the change rates between the two exceeds a certain threshold, the suspension controller 200 increases the power of the motor with a slower change rate or reduces the power of the motor with a faster change rate according to the actual situation (Example 1), or the suspension controller 200 increases the opening of the proportional valve with a slower change rate or reduces the opening of the proportional valve with a faster change rate according to the actual situation (Example 2); in order to ensure that the vehicle body height remains unchanged, the lower chamber control valve 1YA and the upper chamber control valve 2YA must be controlled to be in a non-powered state (the state in the figure is the non-powered state). At this time, the lower chamber control valve 1YA and the upper chamber control valve 2YA are closed, and the oil flow direction of the control valve is from the oil tank 1 to the shock absorber 2, ensuring that the oil in the oil tank 1 can smoothly enter the shock absorber 2; the oil pressure of the rod chamber 22 and the rodless chamber 21 of the shock absorber 2 reaches the target value P3 desire1 and P4 desire1 Afterwards, the suspension controller 200 controls the lower cavity control motor ME1 and the upper cavity control motor ME2 to stop outputting power. At this time, the pressure of the shock absorber 2 can be maintained, so that the suspension is maintained at the required stiffness value.

[0038] In step S4, if the stiffness of the suspension needs to be reduced and the pressure of the shock absorber 2 needs to be reduced, the suspension controller 200 calculates the pressure value (ie, target pressure value) P3 required for the stiffness at the current moment. desire2 =P3 actual2 -ΔP32, P4 desire2 =P4 actual2 -ΔP42, based on the calculated target pressure value P3 desire2 、P4 desire2 The actual pressure value P3 measured by the upper chamber pressure sensor P3 and the lower chamber pressure sensor P4 actual and P4 actualThe lower chamber control valve 1YA and the upper chamber control valve 2YA are controlled to open (powered state), so that the oil flow direction of the lower chamber control valve 1YA and the upper chamber control valve 2YA is changed to flow from the shock absorber 2 to the oil tank 1; at the same time, in order to maintain the height of the shock absorber 2 unchanged, the pressure change rates of the rod chamber 22 and the rodless chamber 21 (upper chamber pressure sensor P3 and lower chamber pressure sensor P4) must be guaranteed to change in the same proportion. When the difference in the change rates of the two exceeds a certain threshold, the suspension controller 200 controls the opening and closing of the lower chamber control valve 1YA and the upper chamber control valve 2YA according to the actual situation (Example 1), or the suspension controller 200 increases the opening of the proportional valve with a slower change rate or decreases the opening of the proportional valve with a faster change rate according to the actual situation (Example 2). After the oil pressure of the shock absorber 2 reaches the target value, the lower chamber control valve 1YA and the upper chamber control valve 2YA are closed (switched to the non-powered state) to maintain the pressure of the shock absorber 2, and thus maintain the stiffness at the required value.

[0039] The present invention calculates the vertical force or roll / pitch moment required for real-time stiffness based on the vehicle's vertical acceleration or roll / pitch angle or angular velocity, distributes it according to the vehicle speed, calculates the target value of the pressure required for stiffness based on the distributed value and the actual pressure values ​​of the sensors in the rod chamber 22 and rodless chamber 21 of the shock absorber 2, controls the motor power and / or valve opening or switch based on the target value and actual value, and adjusts the oil supply pressure in the shock absorber 2 in real time so that the pressure value in the shock absorber 2 reaches the required value, thereby achieving real-time, rapid, and stepless adjustment of stiffness. The present invention achieves real-time, rapid, and stepless adjustment of stiffness during vehicle operation, greatly improving the comfort and stability of the vehicle. The real-time, rapid, and stepless adjustment of stiffness has a wider adjustable range and a better effect on improving vehicle comfort. Moreover, when vibration or impact occurs during vehicle operation, the real-time, rapid, and stepless adjustment of stiffness can timely adjust the stiffness value, thereby protecting the vehicle and having greater advantages in improving vehicle safety.

[0040] The above description is an explanation of the present invention, not a limitation of the present invention. The present invention may be modified in any form without violating the spirit of the present invention.

Claims

1. A hydraulic suspension control method with stepless, rapid, and real-time adjustable stiffness, characterized by: The suspension system (200) receives vehicle information in real time and adjusts the stiffness of the suspension according to the received information, including at least: Calculating a target value of a total roll / pitch moment or a total vertical force required for a required suspension stiffness based on the received vehicle roll / pitch angle information, roll / pitch angular velocity information, or vertical acceleration information; Distribute the total roll / pitch moment or total vertical force to each wheel according to vehicle speed, vertical acceleration, or roll / pitch angle, and convert the moment into force to obtain the vertical force / roll force / pitch force of each wheel; According to the effective areas of the rodless chamber (21) and the rod chamber (22) of the shock absorber (2) of the wheel, as well as the vertical force / rolling force / pitching force, the required pressure change of the rod chamber (22) and the rodless chamber (21) of the shock absorber (2) and the target pressure value of the required stiffness are calculated; according to the target pressure value and the pressure change, the oil pressure of the rod chamber (22) and the rodless chamber (21) is quickly adjusted to the target value by controlling the power of the control motor of the oil circuit and / or the opening of the valve, so that the suspension stiffness is quickly adjusted to the required stiffness value.

2. The method for controlling a hydraulic suspension with stepless, rapid, and real-time stiffness adjustment according to claim 1, characterized in that: During the stiffness adjustment process, the pressure change rates of the rod chamber (22) and the rodless chamber (21) of the shock absorber (2) maintain the same proportional change; when the difference between the change rates of the two exceeds a certain threshold, the suspension controller (200) increases the power of the motor with a slower change rate or reduces the speed of the motor with a faster change rate, or the suspension controller (200) increases the opening of the proportional valve with a slower change rate or reduces the opening of the proportional valve with a faster change rate.

3. The hydraulic suspension control method with stepless, rapid and real-time adjustable stiffness according to claim 1, characterized in that: Control valves are respectively provided on the oil paths of the rod chamber (22) and the rodless chamber (21) of the shock absorber (2); when the stiffness increases, the oil of the control valve flows from the oil tank (1) to the shock absorber (2); when the stiffness decreases, the oil of the control valve flows from the shock absorber (2) to the oil tank (1); after the stiffness reaches the target value, the control valve switches the flow direction.

4. The method for controlling a hydraulic suspension with stepless, rapid, and real-time stiffness adjustment according to claim 1, characterized in that: When distributing the total roll / pitch moment or total vertical force, the total roll / pitch moment or total vertical force is first distributed to the front and rear axles based on the vehicle speed information to obtain the front axle roll / pitch moment or vertical force and the rear axle roll / pitch moment or vertical force. Then, based on the vehicle speed and vertical acceleration or the roll / pitch angle, the front axle roll / pitch moment or vertical force is distributed to the two front wheels, and the rear axle roll / pitch moment or vertical force is distributed to the two rear wheels. Based on the wheelbase or the distance from the center of mass to the front and rear axles, the roll / pitch moment of each wheel is converted into a roll / pitch force to obtain the vertical force / roll force / pitch force of each wheel.

5. The method for controlling a hydraulic suspension with stepless, rapid, and real-time stiffness adjustment according to claim 4, characterized in that: The distribution ratio of the front and rear axles is different at different vehicle speeds; at low speeds, the distribution ratio of the front axle is higher than that of the rear axle; at high speeds, the distribution ratio of the front axle is lower than that of the rear axle; in the medium speed range, the distribution ratio of the front and rear axles is almost equal.

6. The method for controlling a hydraulic suspension with stepless, rapid, and real-time stiffness adjustment according to claim 4, characterized in that: When rolling, the torque distributed to the outer wheel is high and the torque distributed to the inner wheel is small; the larger the roll angle and the higher the vehicle speed, the higher the torque gain of the outer wheel.

7. A hydraulic suspension control system with stepless, rapid, and real-time adjustable stiffness, characterized by: The control method according to claim 1 is used for control, comprising a shock absorption control module (100), a suspension controller (200), an inertial measurement unit (300), a chassis domain control module (400), and an operating mode module (500), wherein each wheel of the vehicle is provided with a shock absorption control module (100), the shock absorption control module (100), the inertial measurement unit (300), the chassis domain control module (400), and the operating mode module (500) are respectively connected to the suspension controller (200), and the shock absorption control module (100) provides the suspension controller (200) with the pressure value of the pressure sensor. The inertial measurement unit (300) provides the suspension controller (200) with information on roll / pitch inclination, roll / pitch angular velocity, and vertical acceleration; the chassis domain control module (400) provides the suspension controller (200) with vehicle speed information; and the operation mode module (500) provides the suspension controller (200) with vehicle operation mode information; an oil tank (1) and a shock absorber (2) are provided on the shock absorption control module (100); a rodless cavity (21) of the shock absorber (2) is connected to the oil tank (1) through a lower cavity oil circuit (10), and a rod cavity (22) is connected to the oil tank (1) through an upper cavity oil circuit (20).

8. The hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness according to claim 7, characterized in that: The lower chamber oil circuit (10) and the upper chamber oil circuit (20) are independently connected to the oil tank (1). An oil pump, a control valve and an energy accumulator are respectively provided on the lower chamber oil circuit (10) and the upper chamber oil circuit (20). The oil pump is connected to the control motor. A pressure sensor is provided between the energy accumulator and the oil chamber of the shock absorber (2). The control motor, the control valve and the pressure sensor are connected to the suspension controller.

9. The hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness according to claim 7, characterized in that: The lower chamber oil circuit (10) and the upper chamber oil circuit (20) are combined into a main oil circuit (30) and connected to the oil tank (1) through the main oil circuit (30); a main oil pump (9) is provided on the main oil circuit (30), and the main oil pump (9) is connected to the main control motor ME; a control valve, an energy accumulator, and a proportional valve are provided on the lower chamber oil circuit (10) and the upper chamber oil circuit (20), respectively; a pressure sensor is provided between the energy accumulator and the oil chamber of the shock absorber (2); the main control motor ME, the control valve, the proportional valve, and the pressure sensor are connected to the suspension controller.

10. The hydraulic suspension control system with stepless, rapid and real-time adjustable stiffness according to claim 7 or 8, characterized in that: One-way valves are respectively provided on the lower chamber oil circuit (10) and the upper chamber oil circuit (20), and the one-way valves are provided between the oil pump or the proportional valve and the control valve.

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