Vehicle hydraulic active suspension system and control method thereof

Abstract

The present application belongs to the technical field of vehicle suspension system, more specifically, it relates to a vehicle hydraulic active suspension system, and also relates to a control method of the vehicle hydraulic active suspension system. The vehicle hydraulic active suspension system comprises multiple groups of control components, the oil cylinder of each group of control components is connected with an oil tank (15) through a first pipeline (31), a drain switch valve is arranged on the first pipeline (31), the oil cylinder is connected with an oil pump pipeline (32) through a second pipeline (32), an accumulator and an oil injection switch valve are arranged on the second pipeline (32), an oil pump (16) is arranged on the oil pump pipeline (33), and the oil pump pipeline (33) is connected with the oil tank (15). The suspension system of the present application adopts a single-pump structure, which can realize the key function of a full-active suspension system, ensure reliable performance, simplify system configuration, reduce the number of parts, reduce costs, and at the same time, reduce the occupied space, improve the integration and operation reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of vehicle suspension systems, and more specifically, relates to a vehicle hydraulic active suspension system. This invention also relates to a control method for a vehicle hydraulic active suspension system. Background Technology

[0002] The vehicle suspension system is a key component connecting the vehicle body and the wheels. Its core function is to transmit the force between the vehicle body and the wheels, dampen vibrations caused by uneven road surfaces, balance the vehicle's ride comfort and handling, and directly affect the vehicle's driving safety, stability, and driving experience.

[0003] Early vehicle suspensions mostly employed passive suspension structures, primarily composed of coil springs with fixed stiffness and shock absorbers with fixed damping. Their mechanical characteristics were fixed, allowing them to passively respond to road vibrations without actively adjusting suspension parameters based on real-time road conditions, vehicle driving status, and driving needs. This passive suspension structure had significant technical limitations: while soft springs could improve ride comfort, they resulted in large body roll during high-speed cornering and noticeable pitch during rapid acceleration or braking, severely impacting handling; while stiff springs could improve handling stability, they exacerbated the transmission of road bumps, significantly reducing ride comfort. In short, passive suspensions could not achieve a balance between comfort and handling, failing to meet the high-end dynamic performance demands of modern vehicles.

[0004] To overcome the performance limitations of passive suspension, active suspension technology has gradually developed. Among them, hydraulic active suspension, with its advantages of high-pressure output, high control precision, and fast response speed, has become a core solution for high-end vehicles to achieve ultimate dynamic performance. The development of hydraulic active suspension has undergone a technological evolution from mechanical hydraulic control to electro-hydraulic servo control: early hydraulic suspension could only achieve manual or simple automatic adjustment of vehicle height, without electronic control modules, belonging to the category of semi-active hydraulic suspension, and could not actively output control force to suppress changes in vehicle attitude; with the integration of electronic and hydraulic technologies, electro-hydraulic servo controlled hydraulic active suspension has gradually matured. By setting up high-pressure hydraulic pumps, electro-hydraulic servo valves, hydraulic actuators, and dedicated ECUs, it can achieve real-time closed-loop control of suspension damping, stiffness, and vehicle attitude, improving ride comfort and handling stability.

[0005] While existing hydraulic active suspension technology has solved the core problems of passive suspension, it still has many technical shortcomings that need to be addressed in practical applications, specifically: High system complexity and high cost: Existing hydraulic active suspension requires the integration of core components such as high-pressure hydraulic pumps, precision electro-hydraulic servo valves, high-pressure hydraulic actuators, multi-channel attitude sensors, and dedicated ECUs. The machining precision and assembly requirements of each component are extremely high, and the system integration is difficult, resulting in hardware costs, R&D and calibration costs, and manufacturing costs far exceeding those of traditional passive suspension. This limits its application to only a few top-tier luxury models, hindering widespread adoption. Severe energy loss and low efficiency: High-pressure hydraulic pumps need to operate continuously or at high frequency to maintain system high pressure, consuming a significant amount of vehicle power (engine power for gasoline vehicles, battery power for electric vehicles), significantly reducing fuel economy or the driving range of electric vehicles. Simultaneously, the hydraulic system experiences throttling losses and leakage losses during operation and cannot recover and utilize suspension vibration energy, further reducing system energy utilization efficiency. Poor reliability and high maintenance costs: Hydraulic systems typically operate at pressures as high as 150-300 bar, placing extremely stringent requirements on the cleanliness of high-pressure seals, hydraulic lines, and hydraulic oil. Over long-term use, seals are prone to aging and leakage, and impurities in the hydraulic oil can easily clog precision components such as electro-hydraulic servo valves, leading to decreased system control accuracy and frequent malfunctions. Furthermore, fault diagnosis and repair require specialized equipment and skilled technicians, resulting in short maintenance cycles and high costs, negatively impacting the user experience. Heavy weight and difficult layout: Components such as high-pressure hydraulic pumps, accumulators, hydraulic lines, and hydraulic actuators are relatively heavy, increasing the vehicle's sprung / unsprung weight. This not only deteriorates vehicle acceleration, braking, and handling performance but also occupies significant chassis space, posing a high risk of interference with the layout of steering, braking, and drive systems, thus increasing the difficulty of vehicle chassis design and assembly. Therefore, there is room for improvement in existing hydraulic active suspension systems. Insufficient thermal management and poor performance stability: Hydraulic systems generate a large amount of heat during high-frequency operation and throttling, causing the hydraulic oil temperature to rise rapidly. If heat dissipation is not timely, the hydraulic oil viscosity will decrease, leakage will increase, and the system control accuracy will be reduced. In low-temperature environments, the hydraulic oil viscosity increases dramatically, leading to slower system response and increased energy consumption, further affecting the working stability of the hydraulic active suspension. In addition, the control algorithms of existing hydraulic active suspensions are mostly based on real-time road condition feedback adjustment, lacking advance prediction of road conditions, making it difficult to achieve a "magic carpet" driving experience. At the same time, the coordination and control accuracy between various components is insufficient, and under complex road conditions (such as continuous bumps, sharp curves, and emergency braking), problems such as stiff vehicle posture control and lag response are prone to occur, failing to fully realize the performance advantages of hydraulic active suspension. In summary, existing hydraulic active suspension technology has achieved an upgrade from passive to active, solving the problem of the incompatibility between comfort and handling in traditional passive suspensions. However, it still has technical defects such as system complexity, high cost, high energy consumption, poor reliability, difficult layout, and insufficient performance stability, which limit its widespread application.

[0006] Existing technology includes a designation titled "A Vehicle and Its Suspension System," with publication number "207523391U." This technology provides a vehicle and its suspension system capable of adapting to various road conditions, achieving optimal vibration reduction, and improving vehicle handling stability and off-road mobility. The suspension system of this invention includes a controller, an accumulator, and lifting cylinders corresponding to each tire. Each lifting cylinder is connected to its corresponding tire via a piston rod. The rodless chamber of each lifting cylinder is connected to the oil portion of the accumulator via an adjustable damping valve. The controller actively regulates oil pressure by controlling the inlet and outlet of the rodless chambers, semi-actively regulates damping by controlling the throttle opening of the adjustable damping valve, and semi-actively regulates stiffness by controlling the charging and discharging of the gas portion of the accumulator. This invention controls large-amplitude vehicle body vibrations at low speeds through oil pressure regulation and can adjust vehicle height to improve handling and off-road performance. It also improves ride comfort by controlling high-frequency, small-amplitude vibrations through damping and stiffness adjustment. However, this technology does not address the technical issues and solutions of this application. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a vehicle hydraulic active suspension system that adopts a single pump structure to achieve the key functions of a fully active suspension system, ensures reliable performance, simplifies system configuration, reduces the number of parts, lowers costs, and at the same time reduces the space occupied by the layout, improves integration and operational reliability.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to a vehicle hydraulic active suspension system, comprising multiple sets of control components. The cylinder of each control component is connected to an oil tank via a first pipeline. An oil drain valve is installed on the first pipeline. The cylinder is connected to an oil pump pipeline via a second pipeline. An accumulator and an oil injection valve are installed on the second pipeline. An oil pump is installed on the oil pump pipeline, and the oil pump pipeline is connected to the oil tank.

[0009] The hydraulic cylinders include a left front hydraulic cylinder, a right front hydraulic cylinder, a left rear hydraulic cylinder, and a right rear hydraulic cylinder; the drain valves include a left front drain valve, a right front drain valve, a left rear drain valve, and a right rear drain valve; the accumulators include a left front accumulator, a right front accumulator, a left rear accumulator, and a right rear accumulator; and the fill valves include a left front fill valve, a right front fill valve, a left rear fill valve, and a right rear fill valve.

[0010] The left front hydraulic cylinder is connected to the oil tank via a first pipeline, on which a left front drain valve is installed. The left front hydraulic cylinder is connected to the oil pump pipeline via a second pipeline, on which a left front accumulator and a left front filler switch are installed. The right front hydraulic cylinder is connected to the oil tank via a first pipeline, on which a right front drain valve is installed. The right front hydraulic cylinder is connected to the oil pump pipeline via a second pipeline, on which a right front accumulator and a right front filler switch are installed.

[0011] The left rear hydraulic cylinder is connected to the oil tank via a first pipeline, on which a left rear drain valve is installed. The left rear hydraulic cylinder is also connected to the oil pump pipeline via a second pipeline, on which a left rear accumulator and a left rear oil filling switch are installed. The right rear hydraulic cylinder is connected to the oil tank via a first pipeline, on which a right rear drain valve is installed. The right rear hydraulic cylinder is also connected to the oil pump pipeline via a second pipeline, on which a right rear accumulator and a right rear oil filling switch are installed.

[0012] The left front spring sits on the left front spring tray, which is an integral part of the left front cylinder. The piston of the left front CDC shock absorber is located inside the left front cylinder, and the piston rod of the left front CDC shock absorber is connected to the vehicle body. The right front spring sits on the right front spring tray, which is an integral part of the right front cylinder. The piston of the right front CDC shock absorber is located inside the right front cylinder, and the piston rod of the right front CDC shock absorber is connected to the vehicle body. The left rear spring sits on the left rear spring tray, which is an integral part of the left rear cylinder. The piston of the left rear CDC shock absorber is located inside the left rear cylinder, and the piston rod of the left rear CDC shock absorber is connected to the vehicle body. The right rear spring sits on the right rear spring tray, which is an integral part of the right rear cylinder. The piston of the right rear CDC shock absorber is located inside the right rear cylinder, and the piston rod of the right rear CDC shock absorber is connected to the vehicle body.

[0013] The vehicle hydraulic active suspension system is configured to switch between comfort mode, anti-roll mode, anti-pitch mode, and single-point rapid lift / lower mode.

[0014] In comfort mode, the hydraulic active suspension system of the vehicle has the hydraulic pressure in the left front cylinder, right front cylinder, left rear cylinder, and right rear cylinder at the design pressure. The damping force is provided by the left front CDC shock absorber, right front CDC shock absorber, left rear CDC shock absorber, and right rear CDC shock absorber. The hydraulic fluid in the left front CDC shock absorber is not connected to the hydraulic fluid in the left front cylinder, thus decoupling the CDC shock absorber and ensuring the comfort of the system.

[0015] The front left, front right, rear left, and rear right CDC dampers are either single-valve or double-valve CDC dampers. The front left, front right, rear left, and rear right springs are either coil springs or air springs.

[0016] In anti-roll mode, when the vehicle's hydraulic active suspension system tilts to the left, the left front and left rear oil injection valves open, and the oil pump injects oil into the left front and left rear cylinders. The left piston rod rises to support the vehicle body. The right front and right rear oil drain valves open, and the oil in the right front and right rear cylinders flows to the oil tank, causing the pressure to drop. The piston rod descends, pulling the vehicle body to resist its lateral tilt and maintain stability. When the system tilts to the right, the right front and right rear oil injection valves open, and the oil pump injects oil into the right front and right rear cylinders. The piston rod rises to support the vehicle body. The left front and left rear oil drain valves open, and the oil in the left front and left rear cylinders flows to the oil tank, causing the pressure to drop. The left piston rod descends, pulling the vehicle body to resist its lateral tilt and maintain stability.

[0017] In anti-pitch mode, when the vehicle's hydraulic active suspension system accelerates and pitches up, the left and right rear oil injection valves open, and the oil pump injects oil into the left and right rear cylinders. The rear piston rod rises to support the vehicle body. Simultaneously, the front left and front right drain valves open, allowing oil in the left and right front cylinders to flow to the oil tank, reducing pressure. This causes the front piston rod to descend, pulling the vehicle body to resist pitching and maintain stability. Conversely, when decelerating and sinking, the left and right front oil injection valves open, and the oil pump injects oil into the left and right front cylinders. The front piston rod rises to support the vehicle body. Finally, the rear left and right drain valves open, allowing oil in the left and right rear cylinders to flow to the oil tank, reducing pressure. This causes the rear piston rod to descend, pulling the vehicle body to resist pitching and maintain stability. In the single-point rapid lifting / lowering mode, when the left rear suspension rises, the left rear oil injection valve opens, the oil pump injects oil into the left rear cylinder, and the piston rod rises to hold the vehicle body. When the left rear suspension lowers, the left rear drain valve opens, the left rear cylinder drains oil into the oil tank, and the piston rod falls. When the right rear suspension rises, the right rear oil injection valve opens, the oil pump injects oil into the right rear cylinder, and the piston rod rises to hold the vehicle body. When the right rear suspension lowers, the right rear drain valve opens, the right rear cylinder drains oil into the oil tank, and the piston rod falls.

[0018] This invention also relates to a control method for a vehicle hydraulic active suspension system that enables the realization of key functions of a fully active suspension system, ensures reliable performance, simplifies system configuration, reduces the number of parts, lowers costs, and simultaneously reduces the space occupied, improves integration and operational reliability. The control steps of the control method are as follows: S1: In comfort mode, the hydraulic pressure in the cylinder is the design pressure, and the damping force is provided through the CDC damper; the CDC damper is not connected to the hydraulic fluid in the cylinder, thus decoupling the CDC damper and ensuring the comfort of the system. S2: In anti-roll mode, when the system tilts to the left, the oil injection switch valve of the left shock absorber opens, the oil pump injects oil into the left cylinder, the left piston rod rises, and supports the body; the oil drain switch valve of the right side opens, the oil in the right cylinder flows to the oil tank, the pressure drops, the piston rod falls, pulls the body, resists the body's tilting movement, and keeps the body stable. S3: In anti-pitch mode, when accelerating and pitching up, the rear oil injection switch valve opens, the oil pump 16 injects oil into the left oil cylinder, and the rear piston rod rises to support the vehicle body. S4: In single-point rapid lift / lower mode, when the suspension rises, the oil injection switch valve opens, the oil pump injects oil into the oil cylinder, the piston rod rises, and it holds the vehicle body; when the suspension lowers, the oil drain switch valve opens, the oil cylinder drains oil into the oil tank, and the piston rod lowers.

[0019] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The vehicle hydraulic active suspension system of this invention features a structure with multiple sets of control components. Each set of control components is connected to an oil tank via an oil injection line and an oil discharge line. The entire system requires only one oil pump to supply oil to each set of control components and to discharge oil to each set individually. The start and stop of the oil pump are controlled by a control component, as are the opening and closing of the oil drain valve and the oil injection valve. This suspension system, employing a single-pump structure, achieves the key functions of a fully active suspension system, ensuring reliable performance, simplifying system configuration, reducing the number of components, lowering costs, while also reducing space requirements and improving integration and operational reliability. Attached Figure Description

[0020] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a schematic diagram of the structure of the vehicle hydraulic active suspension system described in this invention; Figure 2 This is a schematic diagram of the vehicle hydraulic active suspension system described in the present invention in anti-roll mode; Figure 3 This is a schematic diagram of the vehicle hydraulic active suspension system described in the present invention in anti-pitch mode; Figure 4 This is a schematic diagram of the vehicle hydraulic active suspension system described in the present invention in a single-point rapid lifting / lowering mode; The labels in the attached diagram are as follows: 1-Left front cylinder, 2-Left front spring tray, 3-Left front spring, 4-Left front CDC shock absorber, 5-Left front accumulator, 6-Right front accumulator, 7-Right front CDC shock absorber, 8-Right front spring, 9-Right front spring tray, 10-Right front cylinder, 11-Right front drain valve 4, 12-Left front drain valve 1, 13-Left front filler valve 1, 14-Right front filler valve 2, 15-Oil tank, 16-Oil pump, 17-Left front cylinder 2 - Rear drain valve; 18 - Left rear oil injection valve; 19 - Right rear oil injection valve; 20 - Left rear CDC shock absorber; 21 - Left rear spring; 22 - Left rear spring tray; 23 - Left rear cylinder; 24 - Left rear accumulator; 25 - Right rear accumulator; 26 - Right rear CDC shock absorber; 27 - Right rear spring; 28 - Right rear spring tray; 29 - Right rear cylinder; 30 - Right rear drain valve; 31 - First pipeline; 32 - Second pipeline; 33 - Oil pump pipeline. Detailed Implementation

[0021] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1 - Appendix Figure 4 As shown, this invention relates to a vehicle hydraulic active suspension system, comprising multiple sets of control components. The cylinder of each control component is connected to an oil tank 15 via a first pipeline 31. An oil drain valve is installed on the first pipeline 31. The cylinder is connected to an oil pump pipeline 33 via a second pipeline 32. An accumulator and an oil injection valve are installed on the second pipeline 32. An oil pump 16 is installed on the oil pump pipeline 33, which is also connected to the oil tank 15. This structure addresses the shortcomings of existing technologies by proposing an improved technical solution. In this structural configuration, multiple sets of control components are provided, each connected to the oil tank via an oil injection pipeline and an oil drain pipeline. The entire system requires only one oil pump, enabling separate oil supply and discharge to each control component. The start and stop of the oil pump are controlled by a control component, as are the opening and closing of the oil drain valve and the oil injection valve. The suspension system of the present invention adopts a single pump structure to realize the key functions of a fully active suspension system, ensuring reliable performance, simplifying system configuration, reducing the number of parts, reducing costs, while reducing the space occupied by the layout, improving integration and operational reliability.

[0022] The vehicle hydraulic active suspension system is configured to switch between comfort mode, anti-roll mode, anti-pitch mode, and single-point rapid lift / lower mode.

[0023] In comfort mode, the hydraulic active suspension system of the vehicle has the designed hydraulic pressure in the left front cylinder 1, right front cylinder 10, left rear cylinder 23, and right rear cylinder 29. The damping force is provided by the left front CDC damper 4, right front CDC damper 7, left rear CDC damper 20, and right rear CDC damper 26. The hydraulic fluid in the left front CDC damper 4 is not connected to that in the left front cylinder 1, thus decoupling the CDC damper and ensuring the comfort of the system.

[0024] The front left CDC damper 4, the front right CDC damper 7, the rear left CDC damper 20, and the rear right CDC damper 26 are single-valve or double-valve CDC dampers. The front left spring 3, the front right spring 8, the rear left spring 21, and the rear right spring 27 are coil springs or air springs.

[0025] In anti-roll mode, when the vehicle's hydraulic active suspension system tilts to the left, the left front oil injection valve 13 and the left rear oil injection valve 18 open, and the oil pump 16 injects oil into the left front cylinder 1 and the left rear cylinder 23. The piston rod on the left side rises to support the vehicle body. The right front drain valve 11 and the right rear drain valve 30 open, and the oil in the right front cylinder 10 and the right rear cylinder 29 flows to the oil tank 15. The pressure drops, the piston rod descends, and it pulls the vehicle body to resist the tilt. The system moves to keep the vehicle body stable. When the system tilts to the right, the right front oil injection valve 14 and the right rear oil injection valve 19 open, and the oil pump 16 injects oil into the right front oil cylinder 10 and the right rear oil cylinder 29. The piston rod rises to support the vehicle body. The left front oil drain valve 12 and the left rear oil drain valve 17 open, and the oil in the left front oil cylinder 1 and the left rear oil cylinder 23 flows to the oil tank 15. The pressure drops, and the piston rod on the left side drops to pull the vehicle body and resist the lateral tilt of the vehicle body, keeping the vehicle body stable.

[0026] In anti-pitch mode, when the vehicle's hydraulic active suspension system accelerates and pitches up, the left rear oil injection valve 18 and right rear oil injection valve 19 open, and the oil pump 16 injects oil into the left rear cylinder 23 and right rear cylinder 29. The rear piston rod rises to support the vehicle body. The front left drain valve 11 and front right drain valve 12 open, and the oil in the left front cylinder 1 and right front cylinder 10 flows to the oil tank 15. The pressure drops, and the front piston rod descends to pull the vehicle body and resist the vehicle's pitch. The movement keeps the vehicle body stable; when decelerating and sinking, the left front oil injection switch valve 13 and the right front oil injection switch valve 14 open, and the oil pump 16 injects oil into the left front oil cylinder 1 and the right front oil cylinder 10. The front piston rod rises and supports the vehicle body; the rear left drain switch valve 17 and the right rear drain switch valve 30 open, and the oil in the left rear oil cylinder 23 and the right rear oil cylinder 29 flows to the oil tank 15. The pressure drops, the rear piston rod descends, pulls the vehicle body, resists the pitching motion of the vehicle body, and keeps the vehicle body stable. In the single-point rapid lifting / lowering mode, when the left rear suspension rises, the left rear oil injection valve 18 opens, the oil pump 16 injects oil into the left rear cylinder 23, and the piston rod rises to press against the vehicle body; when the left rear suspension lowers, the left rear drain valve 17 opens, the left rear cylinder 23 drains oil into the oil tank 15, and the piston rod lowers; when the right rear suspension rises, the right rear oil injection valve 19 opens, the oil pump 16 injects oil into the right rear cylinder 29, and the piston rod rises to press against the vehicle body; when the right rear suspension lowers, the right rear drain valve 30 opens, the right rear cylinder 29 drains oil into the oil tank 15, and the piston rod lowers.

[0027] The hydraulic cylinders include a left front hydraulic cylinder 1, a right front hydraulic cylinder 10, a left rear hydraulic cylinder 23, and a right rear hydraulic cylinder 29. The drain valves include a left front drain valve 12, a right front drain valve 11, a left rear drain valve 17, and a right rear drain valve 19. The accumulators include a left front accumulator 5, a right front accumulator 6, a left rear accumulator 24, and a right rear accumulator 25. The oil injection valves include a left front oil injection valve 13, a right front oil injection valve 14, a left rear oil injection valve 18, and a right rear oil injection valve 19.

[0028] The left front cylinder 1 is connected to the oil tank 15 through a first pipeline 31, on which a left front drain valve 12 is installed. The left front cylinder 1 is connected to the oil pump pipeline 33 through a second pipeline 32, on which a left front accumulator 5 and a left front oil injection switch 13 are installed. The right front cylinder 10 is connected to the oil tank 15 through a first pipeline 31, on which a right front drain valve 11 is installed. The right front cylinder 10 is connected to the oil pump pipeline 33 through a second pipeline 32, on which a right front accumulator 6 and a right front oil injection switch 14 are installed.

[0029] The left rear cylinder 23 is connected to the oil tank 15 through a first pipeline 31, on which a left rear drain valve 17 is installed. The left rear cylinder 23 is connected to the oil pump pipeline 33 through a second pipeline 32, on which a left rear accumulator 24 and a left rear oil injection switch 18 are installed. The right rear cylinder 29 is connected to the oil tank 15 through a first pipeline 31, on which a right rear drain valve 30 is installed. The right rear cylinder 29 is connected to the oil pump pipeline 33 through a second pipeline 32, on which a right rear accumulator 25 and a right rear oil injection switch 19 are installed.

[0030] The left front spring 3 sits on the left front spring tray 2. The left front spring tray 2 and the left front cylinder 1 are an integral structure. The piston of the left front CDC shock absorber 4 is located inside the left front cylinder 1, and the piston rod of the left front CDC shock absorber 4 is connected to the vehicle body. The right front spring 8 sits on the right front spring tray 9. The right front spring tray 9 and the right front cylinder 10 are an integral structure. The piston of the right front CDC shock absorber 7 is located inside the right front cylinder 10, and the piston rod of the right front CDC shock absorber 7 is connected to the vehicle body. The left rear spring 21... The left rear spring 27 sits on the left rear spring tray 22, which is an integral structure with the left rear hydraulic cylinder 23. The piston of the left rear CDC shock absorber 20 is located inside the left rear hydraulic cylinder 23, and the piston rod of the left rear CDC shock absorber 20 is connected to the vehicle body. The right rear spring 27 sits on the right rear spring tray 28, which is an integral structure with the right rear hydraulic cylinder 29. The piston of the right rear CDC shock absorber 26 is located inside the right rear hydraulic cylinder 29, and the piston rod of the right rear CDC shock absorber 26 is connected to the vehicle body.

[0031] The vehicle hydraulic active suspension system is configured to switch between comfort mode, anti-roll mode, anti-pitch mode, and single-point rapid lift / lower mode.

[0032] In the structure of the present invention, as Figure 1 As shown, in comfort mode, the hydraulic active suspension system operates at the design pressure in the left front cylinder 1, right front cylinder 10, left rear cylinder 23, and right rear cylinder 29. Damping force is provided through the left front CDC damper 4, right front CDC damper 7, left rear CDC damper 20, and right rear CDC damper 26. The hydraulic fluid in the left front CDC damper 4 is not connected to that in the left front cylinder 1, thus decoupling the CDC dampers and ensuring system comfort. In comfort mode, components such as the oil tank and oil pump do not require intervention.

[0033] The front left CDC damper 4, the front right CDC damper 7, the rear left CDC damper 20, and the rear right CDC damper 26 are single-valve or double-valve CDC dampers. The front left spring 3, the front right spring 8, the rear left spring 21, and the rear right spring 27 are coil springs or air springs.

[0034] In the structure of the present invention, as Figure 2As shown, in anti-roll mode, when the vehicle's hydraulic active suspension system tilts to the left, the left front oil injection valve 13 and the left rear oil injection valve 18 open, and the oil pump 16 injects oil into the left front cylinder 1 and the left rear cylinder 23. The piston rod on the left side rises to support the vehicle body. The right front oil drain valve 11 and the right rear oil drain valve 30 open, and the oil in the right front cylinder 10 and the right rear cylinder 29 flows to the oil tank 15. The pressure drops, the piston rod descends, and it pulls the vehicle body to resist the side tilt of the vehicle body. The system tilts to the right to maintain vehicle stability. When the system tilts to the right, the right front oil injection valve 14 and the right rear oil injection valve 19 open, and the oil pump 16 injects oil into the right front cylinder 10 and the right rear cylinder 29. The piston rod rises to support the vehicle body. The left front oil drain valve 12 and the left rear oil drain valve 17 open, and the oil in the left front cylinder 1 and the left rear cylinder 23 flows to the oil tank 15. The pressure drops, and the left piston rod descends to pull the vehicle body, resisting the tilting motion and keeping the vehicle body stable. In anti-roll mode, the vehicle's roll state can be determined by collecting data on the steering wheel angle, the vehicle's roll angle, and lateral acceleration. When the collected signal value exceeds a certain threshold, the controller determines that the vehicle is in a roll state and controls the opening of the solenoid valve and the start of the oil pump to put the suspension system into anti-roll mode to reduce the vehicle's roll angle and improve overall vehicle safety.

[0035] In the structure of the present invention, as Figure 3 As shown, in anti-pitch mode, when the vehicle's hydraulic active suspension system accelerates and pitches up, the left rear oil injection valve 18 and the right rear oil injection valve 19 open, and the oil pump 16 injects oil into the left rear cylinder 23 and the right rear cylinder 29. The rear piston rod rises to support the vehicle body. The front left drain valve 11 and the front right drain valve 12 open, and the oil in the left front cylinder 1 and the right front cylinder 10 flows to the oil tank 15. The pressure drops, and the front piston rod descends to pull the vehicle body and resist the vehicle's pitching. During pitching motion, the vehicle body remains stable. When decelerating and sinking, the left front oil injection valve 13 and right front oil injection valve 14 open, and the oil pump 16 injects oil into the left front cylinder 1 and right front cylinder 10. The front piston rod rises, supporting the vehicle body. The rear left drain valve 17 and right rear drain valve 30 open, and the oil in the left rear cylinder 23 and right rear cylinder 29 flows to the oil tank 15, reducing pressure. The rear piston rod descends, pulling the vehicle body to resist pitching motion and maintain stability. In anti-pitch mode, the vehicle's pitch state is determined by collecting signals from the brake pedal, vehicle speed, pitch angle, pitch angular velocity, or angular acceleration. When the collected signal value exceeds a certain threshold, the controller determines that the vehicle is in a pitch state and controls the opening of the solenoid valve and the start of the oil pump to put the suspension system into anti-pitch mode to reduce the vehicle's pitch angle and improve overall vehicle safety.

[0036] In the structure of the present invention, as Figure 4As shown, in the single-point rapid lifting / lowering mode of the vehicle's hydraulic active suspension system, when the left rear suspension rises, the left rear oil injection valve 18 opens, the oil pump 16 injects oil into the left rear cylinder 23, and the piston rod rises to press against the vehicle body; when the left rear suspension lowers, the left rear drain valve 17 opens, the left rear cylinder 23 drains oil into the oil tank 15, and the piston rod lowers; when the right rear suspension rises, the right rear oil injection valve 19 opens, the oil pump 16 injects oil into the right rear cylinder 29, and the piston rod rises to press against the vehicle body; when the right rear suspension lowers, the right rear drain valve 30 opens, the right rear cylinder 29 drains oil into the oil tank 15, and the piston rod lowers. In the single-point rapid lifting / lowering mode, the vehicle's single-point rapid lifting / lowering mode can be actively controlled by the user, such as through a mobile app or central control screen, to demonstrate the function. Alternatively, this can be achieved proactively through algorithms. When the vehicle detects obstacles, potholes, or speed bumps on one side ahead, the suspension control system can actively control the wheels to raise or lower, thereby reducing impact, improving vehicle comfort, and preventing damage to vehicle components. Obstacle detection can be achieved through methods such as pre-aiming or front-mounted radar.

[0037] This invention also relates to a control method for a vehicle hydraulic active suspension system that enables the realization of key functions of a fully active suspension system, ensures reliable performance, simplifies system configuration, reduces the number of parts, lowers costs, and simultaneously reduces the space occupied, improves integration and operational reliability. The control steps of the control method are as follows: S1: In comfort mode, the hydraulic pressure in the cylinder is the design pressure, and the damping force is provided through the CDC damper; the CDC damper is not connected to the hydraulic fluid in the cylinder, thus decoupling the CDC damper and ensuring the comfort of the system. S2: In anti-roll mode, when the system tilts to the left, the oil injection switch valve of the left shock absorber opens, the oil pump 16 injects oil into the left cylinder, the piston rod of the left side rises, and supports the body; the oil drain switch valve of the right side opens, the oil in the right cylinder flows to the oil tank 15, the pressure drops, the piston rod drops, pulls the body, resists the body's tilting movement, and keeps the body stable. S3: In anti-pitch mode, when accelerating and pitching up, the rear oil injection switch valve opens, the oil pump 16 injects oil into the left oil cylinder, and the rear piston rod rises to support the vehicle body. S4: In single-point rapid lift / lower mode, when the suspension rises, the oil injection switch valve opens, the oil pump 16 injects oil into the oil cylinder, the piston rod rises, and it holds the vehicle body; when the suspension lowers, the oil drain switch valve opens, the oil cylinder drains oil into the oil tank, and the piston rod lowers.

[0038] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A vehicle hydraulic active suspension system, characterized in that: It includes multiple sets of control components. The cylinder of each control component is connected to the oil tank (15) through the first pipeline (31). A drain valve is installed on the first pipeline (31). The cylinder is connected to the oil pump pipeline (32) through the second pipeline (32). An accumulator and an oil injection valve are installed on the second pipeline (32). An oil pump (16) is installed on the oil pump pipeline (33). The oil pump pipeline (33) is connected to the oil tank (15).

2. The vehicle hydraulic active suspension system according to claim 1, characterized in that: The hydraulic cylinders include a left front hydraulic cylinder (1), a right front hydraulic cylinder (10), a left rear hydraulic cylinder (23), and a right rear hydraulic cylinder (29). The drain valves include a left front drain valve (12), a right front drain valve (11), a left rear drain valve (17), and a right rear drain valve (30). The accumulators include a left front accumulator (5), a right front accumulator (6), a left rear accumulator (24), and a right rear accumulator (25). The oil injection switches include a left front oil injection valve (13), a right front oil injection valve (14), a left rear oil injection valve (18), and a right rear oil injection valve (19).

3. The vehicle hydraulic active suspension system according to claim 2, characterized in that: The left front cylinder (1) is connected to the oil tank (15) through a first pipeline (31). A left front drain valve (12) is installed on the first pipeline (31). The left front cylinder (1) is connected to the oil pump pipeline (33) through a second pipeline (32). A left front accumulator (5) and a left front oil injection switch (13) are installed on the second pipeline (32). The right front cylinder (10) is connected to the oil tank (15) through a first pipeline (31). A right front drain valve (11) is installed on the first pipeline (31). The right front cylinder (10) is connected to the oil pump pipeline (33) through a second pipeline (32). A right front accumulator (6) and a right front oil injection switch (14) are installed on the second pipeline (32).

4. The vehicle hydraulic active suspension system according to claim 3, characterized in that: The left rear cylinder (23) is connected to the oil tank (15) through a first pipeline (31). A left rear oil drain valve (17) is installed on the first pipeline (31). The left rear cylinder (23) is connected to the oil pump pipeline (33) through a second pipeline (32). A left rear accumulator (24) and a left rear oil injection switch (18) are installed on the second pipeline (32). The right rear cylinder (29) is connected to the oil tank (15) through a first pipeline (31). A right rear oil drain valve (30) is installed on the first pipeline (31). The right rear cylinder (29) is connected to the oil pump pipeline (33) through a second pipeline (32). A right rear accumulator (25) and a right rear oil injection switch (19) are installed on the second pipeline (32).

5. The vehicle hydraulic active suspension system according to claim 4, characterized in that: The left front spring (3) sits on the left front spring tray (2). The left front spring tray (2) and the left front cylinder (1) are an integral structure. The piston of the left front CDC damper (4) is located inside the left front cylinder (1), and the piston rod of the left front CDC damper (4) is connected to the vehicle body. The right front spring (8) sits on the right front spring tray (9). The right front spring tray (9) and the right front cylinder (10) are an integral structure. The piston of the right front CDC damper (7) is located inside the right front cylinder (10), and the piston rod of the right front CDC damper (7) is connected to the vehicle body. The left rear spring (2) 1) The left rear spring tray (22) sits on the left rear spring tray (22) and the left rear cylinder (23) are integrated structures. The piston of the left rear CDC damper (20) is located in the left rear cylinder (23), and the piston rod of the left rear CDC damper (20) is connected to the vehicle body. The right rear spring (27) sits on the right rear spring tray (28). The right rear spring tray (28) and the right rear cylinder (29) are integrated structures. The piston of the right rear CDC damper (26) is located in the right rear cylinder (29), and the piston rod of the right rear CDC damper (26) is connected to the vehicle body.

6. The vehicle hydraulic active suspension system according to claim 4, characterized in that: In the comfort mode, the hydraulic active suspension system of the vehicle has the design pressure of the oil in the left front cylinder (1), right front cylinder (10), left rear cylinder (23), and right rear cylinder (29). The damping force is provided by the left front CDC damper (4), right front CDC damper (7), left rear CDC damper (20), and right rear CDC damper (26). The oil in the left front CDC damper (4) is not connected to the oil in the left front cylinder (1), thereby decoupling the CDC damper and ensuring the comfort of the system.

7. The vehicle hydraulic active suspension system according to claim 4, characterized in that: In the anti-roll mode, when the vehicle hydraulic active suspension system tilts to the left, the left front oil injection valve (13) and the left rear oil injection valve (18) open, and the oil pump (16) injects oil into the left front cylinder (1) and the left rear cylinder (23). The piston rod on the left side rises to support the vehicle body. The right front drain valve (11) and the right rear drain valve (30) open, and the oil in the right front cylinder (10) and the right rear cylinder (29) flows to the oil tank (15). The pressure drops, the piston rod falls, and it pulls the vehicle body to resist the tilt of the vehicle body. The movement keeps the vehicle body stable. When the system tilts to the right, the right front oil injection switch valve (14) and the right rear oil injection switch valve (19) open, the oil pump (16) injects oil into the right front oil cylinder (10) and the right rear oil cylinder (29), the piston rod rises, and supports the vehicle body. The left front drain oil switch valve (12) and the left rear oil injection switch valve (18) open, the oil in the left front oil cylinder (1) and the left rear oil cylinder (23) flows to the oil tank (15), the pressure drops, the left piston rod drops, pulls the vehicle body, resists the side tilt of the vehicle body, and keeps the vehicle body stable.

8. The vehicle hydraulic active suspension system according to claim 4, characterized in that: In anti-pitch mode, when the vehicle's hydraulic active suspension system accelerates and pitches up, the left rear oil injection valve (18) and right rear oil injection valve (19) open, and the oil pump (16) injects oil into the left rear cylinder (23) and right rear cylinder (29). The rear piston rod rises to support the vehicle body. The front left drain valve (11) and front right drain valve (12) open, and the oil in the left front cylinder 1 and right front cylinder (10) flows to the oil tank (15). The pressure drops, and the front piston rod descends to pull the vehicle body and resist the pitching motion of the vehicle body. When the vehicle body moves, it keeps the vehicle body stable. When the vehicle body decelerates and sinks, the left front oil injection switch valve (13) and the right front oil injection switch valve (14) are opened, and the oil pump (16) injects oil into the left front oil cylinder (1) and the right front oil cylinder (10). The piston rod at the front rises and supports the vehicle body. The rear left drain switch valve (17) and the right rear drain switch valve (30) are opened, and the oil in the left rear oil cylinder (23) and the right rear oil cylinder (29) flows to the oil tank (15). The pressure drops, the piston rod at the rear drops, pulls the vehicle body, resists the pitching motion of the vehicle body, and keeps the vehicle body stable.

9. The vehicle hydraulic active suspension system according to claim 4, characterized in that: In the single-point rapid lifting / lowering mode of the vehicle hydraulic active suspension system, when the left rear suspension rises, the left rear oil injection switch valve (18) opens, the oil pump (16) injects oil into the left rear cylinder (23), the piston rod rises, and presses against the vehicle body; when the left rear suspension lowers, the left rear drain switch valve (17) opens, the left rear cylinder (23) drains oil into the oil tank (15), and the piston rod lowers; when the right rear suspension rises, the right rear oil injection switch valve (19) opens, the oil pump (16) injects oil into the right rear cylinder (29), the piston rod rises, and presses against the vehicle body; when the right rear suspension lowers, the right rear drain switch valve (30) opens, the right rear cylinder (29) drains oil into the oil tank (15), and the piston rod lowers.

10. The control method for a vehicle hydraulic active suspension system according to claim 4, characterized in that: S1: In comfort mode, the hydraulic pressure in the cylinder is the design pressure, and the damping force is provided through the CDC damper; the CDC damper is not connected to the hydraulic fluid in the cylinder, thus decoupling the CDC damper and ensuring the comfort of the system. S2: In anti-roll mode, when the system tilts to the left, the oil injection switch valve of the left shock absorber opens, the oil pump (16) injects oil into the left cylinder, the piston rod of the left side rises and supports the body; the oil drain switch valve of the right side opens, the oil in the right cylinder flows to the oil tank (15), the pressure drops, the piston rod drops, pulls the body, resists the body's tilting movement, and keeps the body stable. S3: In anti-pitch mode, when accelerating and pitching up, the rear oil injection switch valve opens, the oil pump 16 injects oil into the left oil cylinder, and the rear piston rod rises to support the vehicle body. S4: In single-point rapid lifting / lowering mode, when the suspension rises, the oil injection switch valve opens, the oil pump (16) injects oil into the oil cylinder, the piston rod rises, and it holds the body; when the suspension lowers, the oil drain switch valve opens, the oil cylinder drains oil into the oil tank, and the piston rod falls.

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