Active hydraulic interconnection suspension system and control method

Abstract

The invention relates to an active hydraulic interconnection suspension system and a control method, the active hydraulic interconnection suspension system comprises a plurality of hydraulic units and a loop control unit, the loop control unit comprises a first loop control assembly and a second loop control assembly, the first hydraulic unit is connected with the first loop control assembly, and the second hydraulic unit is connected with the second loop control assembly. The first hydraulic unit is connected with the first loop control assembly, the second hydraulic unit is connected with the second loop control assembly, the third hydraulic unit is connected with the second loop control assembly, the fourth hydraulic unit is connected with the first loop control assembly, and the first hydraulic unit and the second hydraulic unit are symmetrically arranged on the two sides of the suspension. The third hydraulic unit and the fourth hydraulic unit are symmetrically arranged on the two sides of the suspension. The first hydraulic unit and the third hydraulic unit are arranged on the same side, and the second hydraulic unit and the fourth hydraulic unit are arranged on the same side. The invention provides a novel active hydraulic interconnection suspension system, so that the active hydraulic interconnection suspension can actively resist roll or pitch.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle suspensions, and in particular, to an active hydraulic interconnected suspension system and a control method thereof. Background Art

[0002] A vehicle suspension system includes a force transmission connection device between a vehicle frame (or a unitized body) and an axle (or a wheel), which is used to transmit the vertical reaction force, longitudinal reaction force, and lateral reaction force acting on the wheel by the road surface, as well as the torque generated therefrom, to the vehicle frame (or the unitized body) to ensure the normal driving of the vehicle. With the development of the automotive industry, users' demands for the ride comfort, handling stability, and safety of vehicles are increasing day by day. Specifically, when the vehicle is making a sharp turn, the anti-roll configuration of the hydraulic interconnected suspension can reduce the roll angle and improve the safety under extreme steering conditions. When braking or accelerating suddenly, the anti-pitch configuration can effectively reduce the pitch angle and keep the vehicle stable. When vertical vibration occurs, the anti-vertical vibration configuration can reduce the vibration transmitted to the vehicle body and enhance the ride comfort of the vehicle.

[0003] However, the traditional passive hydraulic interconnected suspension system has limitations. For example, although the anti-roll configuration can effectively suppress roll, its suppression effect on pitch and vertical vibration is limited. Similarly, the anti-pitch configuration and the anti-vertical vibration configuration also have similar limitations.

[0004] For example, CN107297997A discloses a vehicle suspension system and a motor vehicle. The first hydraulic branch pipe and the second hydraulic branch pipe of the vehicle suspension system are both connected to the first hydraulic cylinder and the second hydraulic cylinder, the third hydraulic branch pipe and the fourth hydraulic branch pipe are both connected to the third hydraulic cylinder and the fourth hydraulic cylinder, both ends of the first hydraulic main pipe are respectively connected to the first hydraulic branch pipe and the third hydraulic branch pipe, both ends of the second hydraulic main pipe are respectively connected to the second hydraulic branch pipe and the fourth hydraulic branch pipe, a first reversing valve is arranged in the first hydraulic branch pipe and the second hydraulic branch pipe, a second reversing valve is arranged in the third hydraulic branch pipe and the fourth hydraulic branch pipe, and a third reversing valve is arranged in the first hydraulic main pipe and the second hydraulic main pipe. In this patent, the first hydraulic cylinder, the second hydraulic cylinder, the third hydraulic cylinder, and the fourth hydraulic cylinder are always in an interconnected state, and the damping valves arranged in the pipeline will affect each other, the control of the damping valves is not precise enough, and multiple reversing valves are used, and multiple modes are switched frequently, resulting in a relatively high cost.

[0005] For another example, CN108944327A discloses a double-layer automatically adjustable suspension applicable to hilly and mountainous areas. A lower suspension hydraulic function unit is provided at each of the four corner parts of the lower-layer hydraulic independent adjustment suspension. First horizontal sensors are provided in the middle of the four beams of the lower suspension. Each lower suspension hydraulic function unit is independently controlled and the level of the lower suspension is adjusted in real time according to the monitoring data of each first horizontal sensor; the upper-layer hydraulic synchronous interconnection suspension is fixedly arranged on the upper part of the lower suspension. The upper suspension hydraulic function unit is divided into two groups, namely the upper suspension front frame hydraulic function unit and the upper suspension rear frame hydraulic function unit, and a synchronous motor is provided in each group; second horizontal sensors are provided in the middle of the cross beams on both sides of the upper suspension, and a pair of hydraulic cylinders on the front and rear sides of the lower suspension are synchronously controlled. In this technical solution, each hydraulic cylinder is independently controlled, and the working mode on different terrains is realized by adjusting the vehicle frame. However, this technical solution is only applicable to the terrain of hilly and mountainous areas, and for flat ordinary roads, the effects of its automatic anti-pitching and anti-roll still need to be strengthened.

[0006] The present invention relates to a hydraulic interconnection suspension system, aiming to significantly improve the ride comfort, handling stability and safety of a vehicle through its configurations for anti-roll, anti-pitch and anti-vertical vibration.

[0007] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, although the applicant has studied a large number of documents and patents when making the present invention, all details and content are not listed in detail due to space limitations. However, this does not mean that the present invention does not possess the features of these prior arts. On the contrary, the present invention already possesses all the features of the prior arts, and the applicant reserves the right to add relevant prior arts in the background art. Summary of the Invention

[0008] Traditional passive hydraulic interconnection suspension systems have some limitations in suppressing vehicle roll, pitch and vertical vibration. For example, a suspension system with an anti-roll configuration can effectively reduce vehicle roll, but has limited effects on suppressing pitch and vertical vibration. Similarly, suspension systems with anti-pitch configurations and anti-vertical vibration configurations also have similar limitations. These traditional suspension systems cannot fully meet the stability and comfort requirements of vehicles under various road conditions.

[0009] Aiming at the deficiencies of the prior art, the present invention provides an active hydraulically interconnected suspension system from the first aspect, which includes a plurality of hydraulic units and a circuit control unit. The circuit control unit includes a first circuit control component and a second circuit control component. The first hydraulic unit is connected to the first circuit control component through a first hydraulic branch and a second hydraulic branch respectively. The second hydraulic unit is connected to the second circuit control component through a third hydraulic branch and a fourth hydraulic branch respectively. The third hydraulic unit is connected to the second circuit control component through a fifth hydraulic branch and a sixth hydraulic branch respectively. The fourth hydraulic unit is connected to the first circuit control component through a seventh hydraulic branch and an eighth hydraulic branch respectively. Among them, the first hydraulic unit and the second hydraulic unit are symmetrically arranged on both sides of the suspension, and the third hydraulic unit and the fourth hydraulic unit are symmetrically arranged on both sides of the suspension; and the first hydraulic unit and the third hydraulic unit are arranged on the same side, and the second hydraulic unit and the fourth hydraulic unit are arranged on the same side.

[0010] According to a preferred embodiment, the hydraulic unit includes an actuator, a rebound adjustable damping valve, a compression adjustable damping valve, an accumulator and a switch solenoid valve. The upper chamber of the actuator is connected to the rebound adjustable damping valve, and the lower chamber of the actuator is connected to the compression adjustable damping valve. The rebound adjustable damping valve is communicated with the compression adjustable damping valve, and the compression adjustable damping valve is connected to the accumulator. A switch solenoid valve is arranged between the hydraulic branch connected to the rebound adjustable damping valve and the hydraulic branch connected to the accumulator.

[0011] According to a preferred embodiment, when the vehicle is in a non-roll state and a non-pitch state, the first circuit control component and the second circuit control component are in a normally closed state; when the vehicle is in a roll state or a pitch state, the first circuit control component and the second circuit control component are in an open state, and the first hydraulic unit is communicated with the fourth hydraulic unit, and the second hydraulic unit is communicated with the third hydraulic unit, so that each hydraulic unit generates an upward or downward acting force on the vehicle body to prevent the suspension from rolling or pitching.

[0012] According to a preferred embodiment, the first circuit control component includes a first circuit control normally closed valve, and the second circuit control component includes a second circuit control normally closed valve. The first circuit control normally closed valve is respectively communicated with the first hydraulic branch, the second hydraulic branch, the seventh hydraulic branch and the eighth hydraulic branch; the second circuit control normally closed valve is respectively communicated with the third hydraulic branch, the fourth hydraulic branch, the fifth hydraulic branch and the sixth hydraulic branch. The first circuit control normally closed valve controls the communication between the first hydraulic branch and the eighth hydraulic branch, and the second hydraulic branch and the seventh hydraulic branch; the second circuit control normally closed valve controls the communication between the third hydraulic branch and the sixth hydraulic branch, and the fourth hydraulic branch and the fifth hydraulic branch.

[0013] According to a preferred embodiment, the first loop control component includes a fifth solenoid valve and a sixth solenoid valve, and the second loop control component includes a seventh solenoid valve and an eighth solenoid valve. The fifth solenoid valve is respectively communicated with the second hydraulic branch and the seventh hydraulic branch; the sixth solenoid valve is respectively communicated with the first hydraulic branch and the eighth hydraulic branch; the seventh solenoid valve is respectively communicated with the third hydraulic branch and the sixth hydraulic branch; the eighth solenoid valve is respectively communicated with the fourth hydraulic branch and the fifth hydraulic branch.

[0014] According to a preferred embodiment, when the vehicle is in a roll state, the actuators in the first hydraulic unit and the third hydraulic unit move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuator increases, so that the first hydraulic unit and the third hydraulic unit generate an upward acting force relative to the vehicle body. At the same time, the actuators in the second hydraulic unit and the fourth hydraulic unit move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuator increases, so that the second hydraulic unit and the fourth hydraulic unit generate a downward acting force relative to the vehicle body. Under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-roll moment.

[0015] According to a preferred embodiment, when the vehicle is in a pitch state, the actuators in the first hydraulic unit and the second hydraulic unit move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuator increases, so that the first hydraulic unit and the second hydraulic unit generate an upward acting force relative to the vehicle body. At the same time, the actuators in the third hydraulic unit and the fourth hydraulic unit move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuator increases, so that the third hydraulic unit and the fourth hydraulic unit generate a downward acting force relative to the vehicle body. Under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-pitch moment.

[0016] The present invention provides a control method for an active hydraulic interconnected suspension system from a second aspect. The method includes: when the vehicle is in a non-roll state and a non-pitch state, the first loop control component and the second loop control component are in a normally closed state;

[0017] When the vehicle is in a roll state or a pitch state, the first loop control component and the second loop control component are in an open state, the first hydraulic unit is communicated with the fourth hydraulic unit, and the second hydraulic unit is communicated with the third hydraulic unit, so that each hydraulic unit generates an upward or downward acting force on the vehicle body to prevent the suspension from rolling or pitching; wherein, the active hydraulic interconnected suspension system includes a plurality of hydraulic units and a loop control unit, the loop control unit includes a first loop control component and a second loop control component, the first hydraulic unit is respectively connected with the first loop control component through a first hydraulic branch and a second hydraulic branch, the second hydraulic unit is respectively connected with the second loop control component through a third hydraulic branch and a fourth hydraulic branch, the third hydraulic unit is respectively connected with the second loop control component through a fifth hydraulic branch and a sixth hydraulic branch, the fourth hydraulic unit is respectively connected with the first loop control component through a seventh hydraulic branch and an eighth hydraulic branch, the first hydraulic unit and the second hydraulic unit are symmetrically arranged on both sides of the suspension, and the third hydraulic unit and the fourth hydraulic unit are symmetrically arranged on both sides of the suspension; and the first hydraulic unit and the third hydraulic unit are arranged on the same side, and the second hydraulic unit and the fourth hydraulic unit are arranged on the same side.

[0018] According to a preferred embodiment, the method further includes: when the vehicle is in a roll state, controlling the actuators in the first hydraulic unit and the third hydraulic unit to move downward respectively, the oil pressure difference between the upper and lower chambers of the actuator increases, so that the first hydraulic unit and the third hydraulic unit generate an upward acting force relative to the vehicle body, and at the same time controlling the actuators in the second hydraulic unit and the fourth hydraulic unit to move upward respectively, the oil pressure difference between the upper and lower chambers of the actuator increases, so that the second hydraulic unit and the fourth hydraulic unit generate a downward acting force relative to the vehicle body, and under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-roll moment.

[0019] According to a preferred embodiment, the method further includes: when the vehicle is in a pitch state, controlling the actuators in the first hydraulic unit and the second hydraulic unit to move downward respectively, the oil pressure difference between the upper and lower chambers of the actuator increases, so that the first hydraulic unit and the second hydraulic unit generate an upward acting force relative to the vehicle body, and at the same time controlling the actuators in the third hydraulic unit and the fourth hydraulic unit to move upward respectively, the oil pressure difference between the upper and lower chambers of the actuator increases, so that the third hydraulic unit and the fourth hydraulic unit generate a downward acting force relative to the vehicle body, and under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-pitch moment. Description of the Drawings

[0020] Figure 1 is a schematic connection structure diagram of the active hydraulic interconnected suspension system provided by the present invention;

[0021] Figure 2 is a schematic connection structure diagram of another preferred active hydraulic interconnected suspension system provided by the present invention;

[0022] Figure 3 It is a schematic structural diagram of the actuator of the active hydraulically interconnected suspension system provided by the present invention;

[0023] Figure 4 It is a schematic logic diagram of the control method of the active hydraulically interconnected suspension system provided by the present invention;

[0024] Figure 5 It is a schematic flow diagram of the control method of the active hydraulically interconnected suspension system provided by the present invention.

[0025] List of reference numerals

[0026] 100: First hydraulic unit; 200: Second hydraulic unit; 300: Third hydraulic unit; 400: Fourth hydraulic unit; 500: First loop control component; 600: Second loop control component; 101: Piston rod; 102: Guide sleeve; 103: Upper chamber; 104: Oil passage; 105: Lower chamber; 106: Cylinder bottom; 107: First accumulator; 108: First hydraulic branch; 109: Second hydraulic branch; 110: First switch solenoid valve; 111: Second switch solenoid valve; 112: Second accumulator; 113: Third hydraulic branch; 114: Fourth hydraulic branch; 115: Fifth hydraulic branch; 116: Sixth hydraulic branch; 117: Third accumulator; 118: Third switch solenoid valve; 119: Fourth switch solenoid valve; 120: Seventh hydraulic branch; 121: Eighth hydraulic branch; 122: Fourth accumulator; 123: First loop control normally closed valve; 124: Second loop control normally closed valve; 125: Fifth switch solenoid valve; 126: Sixth switch solenoid valve; 127: Seventh switch solenoid valve; 128: Eighth switch solenoid valve; 210: First actuator; 220: Second actuator; 230: Third actuator; 240: Fourth actuator; 301: First rebound adjustable damping valve; 302: Second rebound adjustable damping valve; 303: Third rebound adjustable damping valve; 304: Fourth rebound adjustable damping valve; 401: First compression adjustable damping valve; 402: Second compression adjustable damping valve; 403: Third compression adjustable damping valve; 404: Fourth compression adjustable damping valve; 501: Integrated valve block; 502: Rebound valve main valve; 503: Rebound adjustable valve; 504: Upper chamber oil port; 505: Compression valve main valve; 506: Lower chamber oil port; 507: Compression adjustable valve. Detailed implementation manners

[0027] The following is a detailed description with reference to the accompanying drawings.

[0028] The present invention explains some terms.

[0029] Hydraulic unit: In an automotive suspension system, it refers to a component that includes hydraulic components and actuators, used to control the damping force and stiffness of the suspension to adapt to different driving conditions and improve ride comfort.

[0030] Circuit control unit: A key component in the suspension system, responsible for managing and controlling the hydraulic flow between hydraulic units to ensure that the suspension system can be adjusted according to the vehicle's dynamic response.

[0031] Actuator: An actuating element in the suspension system, usually a hydraulic cylinder, which changes the stroke and stiffness of the suspension through hydraulic action to adjust the vehicle's dynamic performance.

[0032] Rebound adjustable damping valve: A type of valve in the suspension system that controls the flow resistance of the liquid during the rebound process after the end of the compression stroke of the suspension, thereby adjusting the rebound damping force of the suspension.

[0033] Compression adjustable damping valve: Another type of valve in the suspension system that controls the flow resistance of the liquid during the compression stroke of the suspension and adjusts the compression damping force of the suspension to adapt to different road surfaces and driving conditions.

[0034] Accumulator: An energy storage element in the suspension system that can store the pressure energy of hydraulic oil and release it when needed to help the suspension system respond quickly and provide a smooth driving experience.

[0035] Switch solenoid valve: A control element in the suspension system that controls the flow path and flow rate of hydraulic oil through electromagnetic action to achieve rapid adjustment of the suspension damping force.

[0036] Embodiment 1

[0037] Traditional passive hydraulically interconnected suspension systems have limitations. For example, although the anti-roll configuration can effectively suppress roll, its suppression effect on pitch and vertical vibrations is limited. Similarly, the anti-pitch configuration and the anti-vertical vibration configuration also have similar limitations.

[0038] The present invention provides an active hydraulically interconnected suspension system, including a plurality of hydraulic units and a circuit control unit. As Figure 1 shown, the circuit control unit includes a first circuit control component 500 and a second circuit control component 600. The hydraulic units include a first hydraulic unit 100, a second hydraulic unit 200, a third hydraulic unit 300, and a fourth hydraulic unit 400. The first hydraulic unit 100 and the second hydraulic unit 200 are symmetrically arranged on both sides of the suspension. The third hydraulic unit 300 and the fourth hydraulic unit 400 are symmetrically arranged on both sides of the suspension. And the first hydraulic unit 100 and the third hydraulic unit 300 are arranged on the same side. The second hydraulic unit 200 and the fourth hydraulic unit 400 are arranged on the same side.

[0039] As Figure 1 and Figure 2 shown, the first hydraulic unit 100 is respectively connected to the first circuit control assembly 500 through the first hydraulic branch 108 and the second hydraulic branch 109. The second hydraulic unit 200 is respectively connected to the second circuit control assembly 600 through the third hydraulic branch 113 and the fourth hydraulic branch 114. The third hydraulic unit 300 is respectively connected to the second circuit control assembly 600 through the fifth hydraulic branch 115 and the sixth hydraulic branch 116. The fourth hydraulic unit 400 is respectively connected to the first circuit control assembly 500 through the seventh hydraulic branch 120 and the eighth hydraulic branch 121.

[0040] As Figure 1 and Figure 2 shown, each hydraulic unit includes an actuator, a rebound adjustable damping valve, a compression adjustable damping valve, an accumulator and a switching solenoid valve. The oil passage 104 of the actuator is separated by a piston into an upper chamber 103 and a lower chamber 105. Preferably. A seal is provided on the piston. The upper chamber 103 and the lower chamber 105 can only be communicated or disconnected through the first hydraulic branch 109 and the second hydraulic branch 109.

[0041] The lower chamber 105 is a chamber including a cylinder bottom 106. The upper chamber 103 is a chamber provided with a piston rod 101. A guide sleeve 102 is provided at the opening of the upper chamber 103 for restricting the moving direction of the piston rod 101. The upper chamber 103 of the actuator is connected to the rebound adjustable damping valve. The lower chamber 105 of the actuator is connected to the compression adjustable damping valve. The rebound adjustable damping valve and the compression adjustable damping valve are communicated or disconnected through a switching solenoid valve. The compression adjustable damping valve is connected to the accumulator. A switching solenoid valve is provided between the hydraulic branch connected to the rebound adjustable damping valve and the hydraulic branch connected to the accumulator.

[0042] Figure 3 shows the structure of another first actuator 210. Taking the structure of the first actuator 210 as an example, the structures of each actuator are described. As Figure 3 shown, an integrated valve block 501 and a rebound valve main valve 502 are provided in the upper chamber oil port 504 of the first actuator 210, and a rebound adjustable valve 503 is provided outside the upper chamber oil port 504. A compression valve main valve 505 is provided in the lower chamber oil port 506 of the first actuator 210, and a compression adjustable valve 507 is provided outside the lower chamber oil port 506. A first switching solenoid valve 110 is provided between the rebound adjustable valve 503 and the compression adjustable valve 507. The compression adjustable valve 507 outside the lower chamber oil port 506 is connected to the first accumulator 107.

[0043] Both the main compression valve 505 and the main return valve 502 are check valve structures. When the hydraulic oil flows out of the first actuator 210 into the hydraulic circuit, the check valve is in a closed state. When the hydraulic oil flows from the hydraulic circuit into the first actuator 210, the check valve can open, and the hydraulic oil can quickly flow back into the first actuator 210.

[0044] The structures of the respective hydraulic units of the present invention are described as follows.

[0045] The first hydraulic unit 100 includes a first actuator 210, a first return adjustable damping valve 301, a first compression adjustable damping valve 401, a first accumulator 107, and a first switch solenoid valve 110. The upper chamber 103 of the first actuator 210 is connected to the first return adjustable damping valve 301 through a pipeline. The lower chamber 105 of the first actuator 210 is connected to the first compression adjustable damping valve 401 through a pipeline. The first return adjustable damping valve 301 communicates with the first compression adjustable damping valve 401 through a pipeline. The first compression adjustable damping valve 401 is connected to the first accumulator 107 through a pipeline. A first switch solenoid valve 110 is provided between the first hydraulic branch 108 connected to the first return adjustable damping valve 301 and the second hydraulic branch 109 connected to the first accumulator 107.

[0046] When the upper chamber 103 is compressed, the hydraulic oil in the first actuator 210 flows out of the upper chamber 103, passes through the first return adjustable damping valve 301, enters the first hydraulic branch 108, and finally flows to the second hydraulic branch 109 connected to the first accumulator 107 and flows into the first accumulator 107. At the same time, the hydraulic oil flows back through the pipeline from the first accumulator 107, enters the first compression adjustable damping valve 401, and then flows into the lower chamber 105 of the first actuator 210 through the pipeline. Through the opening and closing control of the first switch solenoid valve 110, the hydraulic oil can flow from the first hydraulic branch 108 to the second hydraulic branch 109, or this passage can be cut off.

[0047] When the lower chamber 105 is compressed, the hydraulic oil in the first actuator 210 flows out of the lower chamber 105, passes through the first compression adjustable damping valve 401, and enters the first accumulator 107. At the same time, the hydraulic oil enters the first hydraulic branch 108 from the second hydraulic branch 109 through the first accumulator 107. The hydraulic oil flows back from the first return adjustable damping valve 301 and enters the upper chamber 103 of the first actuator 210 through the pipeline connected thereto. The first switch solenoid valve 110 controls the flow of the hydraulic oil from the second hydraulic branch 109 to the first hydraulic branch 108 to ensure that the return path of the hydraulic oil can be closed or opened when needed.

[0048] The entire circuit controls the flow of hydraulic oil between the upper and lower chambers of the first actuator 210 through the mutual cooperation of different hydraulic branches, the first rebound adjustable damping valve 301, the first compression adjustable damping valve 401, the first accumulator 107, and the first switching solenoid valve 110, achieving precise control of the hydraulic system. The outflowing hydraulic oil enters the first accumulator 107 after the pressure is adjusted by the first rebound adjustable damping valve 301 and the first compression adjustable damping valve 401 respectively, and then returns to the cavity of the first actuator 210 through the first accumulator 107 and the corresponding first rebound adjustable damping valve 301 and first compression adjustable damping valve 401 during the return flow to achieve pressure balance and energy storage and release.

[0049] As Figure 1 shown, the second hydraulic unit 200 includes a second actuator 220, a second rebound adjustable damping valve 302, a second compression adjustable damping valve 402, a second accumulator 112, and a second switching solenoid valve 111. The upper chamber 103 of the second actuator 220 is connected to the second rebound adjustable damping valve 302. The lower chamber 105 of the second actuator 220 is connected to the second compression adjustable damping valve 402. The second rebound adjustable damping valve 302 communicates with the second compression adjustable damping valve 402. The second compression adjustable damping valve 402 is connected to the second accumulator 112. A second switching solenoid valve 111 is provided between the third hydraulic branch 113 connected to the second rebound adjustable damping valve 302 and the fourth hydraulic branch 114 connected to the second accumulator 112.

[0050] Similarly, when the upper chamber of the second actuator 220 is compressed, the hydraulic oil flows out of the upper chamber, passes through the second rebound adjustable damping valve 302 and enters the third hydraulic branch 113, and finally flows to the fourth hydraulic branch 114 connected to the second accumulator 112 and flows into the second accumulator 112. At the same time, the hydraulic oil returns through the pipeline from the second accumulator 112, enters the second compression adjustable damping valve 402, and then flows into the lower chamber of the second actuator 220 through the pipeline. Through the opening and closing control of the second switching solenoid valve 111, the hydraulic oil can flow from the third hydraulic branch 113 to the fourth hydraulic branch 114, or this passage can be cut off.

[0051] When the lower chamber of the second actuator 220 is compressed, the hydraulic oil in the second actuator 220 flows out of the lower chamber, passes through the second compression adjustable damping valve 402 and enters the second accumulator 112. At the same time, the hydraulic oil enters the third hydraulic branch 113 from the second accumulator 112 through the fourth hydraulic branch 114.

[0052] The hydraulic oil flows back from the second restoring adjustable damping valve 302 and enters the upper chamber of the second actuator 220 through the pipeline connected thereto. The second switch solenoid valve 111 controls the flow of the hydraulic oil from the fourth hydraulic branch 114 to the third hydraulic branch 113 to ensure that the return path of the hydraulic oil can be closed or opened when needed.

[0053] Through the mutual cooperation of different hydraulic branches, the second restoring adjustable damping valve 302, the second compression adjustable damping valve 402, the second accumulator 112, and the second switch solenoid valve 111 in the entire circuit, the flow of the hydraulic oil between the upper and lower chambers of the second actuator 220 is controlled, achieving precise control of the hydraulic system. The outflowing hydraulic oil enters the second accumulator 112 after the pressure is adjusted by the second restoring adjustable damping valve 302 and the second compression adjustable damping valve 402 respectively, and when flowing back, it returns to the cavity of the second actuator 220 through the second accumulator 112 and the corresponding second restoring adjustable damping valve 302 and second compression adjustable damping valve 402 to achieve pressure balance and energy storage and release.

[0054] As Figure 1 shown, the third hydraulic unit 300 includes a third actuator 230, a third restoring adjustable damping valve 303, a third compression adjustable damping valve 403, a third accumulator 117, and a third switch solenoid valve 118. The upper chamber 103 of the third actuator 230 is connected to the third restoring adjustable damping valve 303. The lower chamber 105 of the third actuator 230 is connected to the third compression adjustable damping valve 403. The third restoring adjustable damping valve 303 communicates with the third compression adjustable damping valve 403. The third compression adjustable damping valve 403 is connected to the third accumulator 117. A third switch solenoid valve 118 is provided between the fifth hydraulic branch 115 connected to the third restoring adjustable damping valve 303 and the sixth hydraulic branch 116 connected to the third accumulator 117.

[0055] Similarly, when the upper chamber of the third actuator 230 is compressed, the hydraulic oil flows out from the upper chamber, passes through the third restoring adjustable damping valve 303 and enters the fifth hydraulic branch 115, and finally flows to the sixth hydraulic branch 116 connected to the third accumulator 117 and flows into the third accumulator 117. At the same time, the hydraulic oil flows back from the third accumulator 117 through the pipeline, enters the third compression adjustable damping valve 403, and then flows into the lower chamber of the third actuator 230 through the pipeline. Through the opening and closing control of the third switch solenoid valve 118, the hydraulic oil can flow from the fifth hydraulic branch 115 to the sixth hydraulic branch 116, or this passage can be cut off.

[0056] When the lower chamber of the third actuator 230 is compressed, the hydraulic oil in the third actuator 230 flows out of the lower chamber, passes through the third compression adjustable damping valve 403 and enters the third accumulator 117. At the same time, the hydraulic oil enters the fifth hydraulic branch 115 from the third accumulator 117 through the sixth hydraulic branch 116. The hydraulic oil flows back through the third return adjustable damping valve 303 and enters the upper chamber of the third actuator 230 through the pipeline connected thereto. The third switch solenoid valve 118 controls the flow of the hydraulic oil from the sixth hydraulic branch 116 to the fifth hydraulic branch 115 to ensure that the return path of the hydraulic oil can be closed or opened when needed.

[0057] The entire circuit controls the flow of the hydraulic oil between the upper and lower chambers of the third actuator 230 through the mutual cooperation of different hydraulic branches, the third return adjustable damping valve 303, the third compression adjustable damping valve 403, the third accumulator 117 and the third switch solenoid valve 118, achieving precise control of the hydraulic system. The outflowing hydraulic oil enters the third accumulator 118 after the pressure is adjusted by the third return adjustable damping valve 303 and the third compression adjustable damping valve 403 respectively, and then returns to the chamber of the third actuator 230 through the third accumulator 118 and the corresponding third return adjustable damping valve 303 and third compression adjustable damping valve 403 during the return process to achieve pressure balance and energy storage and release.

[0058] As Figure 1 shown, the fourth hydraulic unit 400 includes a fourth actuator 240, a fourth return adjustable damping valve 304, a fourth compression adjustable damping valve 404, a fourth accumulator 122 and a fourth switch solenoid valve 119. The upper chamber 103 of the fourth actuator 240 is connected to the fourth return adjustable damping valve 304. The lower chamber 105 of the fourth actuator 240 is connected to the fourth compression adjustable damping valve 404. The fourth return adjustable damping valve 304 is communicated with the fourth compression adjustable damping valve 404. The fourth compression adjustable damping valve 404 is connected to the fourth accumulator 122. A fourth switch solenoid valve 119 is provided between the seventh hydraulic branch 120 connected to the fourth return adjustable damping valve 304 and the eighth hydraulic branch 121 connected to the fourth accumulator 122.

[0059] Similarly, when the upper chamber of the fourth actuator 240 is compressed, the hydraulic oil flows out of the upper chamber, passes through the fourth return adjustable damping valve 304 and enters the seventh hydraulic branch 120, and finally flows to the eighth hydraulic branch 121 connected to the fourth accumulator 112 and flows into the fourth accumulator 122. At the same time, the hydraulic oil returns through the pipeline, enters the fourth compression adjustable damping valve 404, and then flows into the lower chamber of the fourth actuator 240 through the pipeline. Through the opening and closing control of the fourth switch solenoid valve 119, the hydraulic oil can flow from the seventh hydraulic branch 120 to the eighth hydraulic branch 121 or the passage can be cut off.

[0060] When the lower chamber of the fourth actuator 240 is compressed, the hydraulic oil in the fourth actuator 240 flows out of the lower chamber, passes through the fourth compression adjustable damping valve 404 and enters the fourth accumulator 122. At the same time, the hydraulic oil enters the seventh hydraulic branch 120 from the fourth accumulator 122 through the eighth hydraulic branch 121, and enters the fourth rebound adjustable damping valve 304. The hydraulic oil flows back from the fourth rebound adjustable damping valve 304, and enters the upper chamber of the fourth actuator 240 through the pipeline connected thereto. The fourth switch solenoid valve 119 controls the flow of the hydraulic oil from the eighth hydraulic branch 121 to the seventh hydraulic branch 120, ensuring that the return path of the hydraulic oil can be closed or opened when needed.

[0061] The entire circuit controls the flow of the hydraulic oil between the upper and lower chambers of the fourth actuator 240 through the mutual cooperation of different hydraulic branches, the fourth rebound adjustable damping valve 304, the fourth compression adjustable damping valve 404, the fourth accumulator 122, and the fourth switch solenoid valve 119, realizing the precise control of the hydraulic system. The outflowing hydraulic oil enters the fourth accumulator 122 after the pressure is adjusted by the fourth rebound adjustable damping valve 304 and the fourth compression adjustable damping valve 404 respectively, and then returns to the cavity of the fourth actuator 240 through the fourth accumulator 122 and the corresponding fourth rebound adjustable damping valve 304 and fourth compression adjustable damping valve 404 during the return process to achieve pressure balance and energy storage and release.

[0062] There are two ways to set the circuit control unit. As Figure 1 shown, the first circuit control component 500 includes a first circuit control normally closed valve 123. The second circuit control component 600 includes a second circuit control normally closed valve 124. The first circuit control normally closed valve 123 is respectively communicated with the first hydraulic branch 108, the second hydraulic branch 109, the seventh hydraulic branch 120, and the eighth hydraulic branch 121. The second circuit control normally closed valve 124 is respectively communicated with the third hydraulic branch 113, the fourth hydraulic branch 114, the fifth hydraulic branch 115, and the sixth hydraulic branch 116.

[0063] As Figure 2 shown, the first circuit control component 500 includes a fifth switch solenoid valve 125 and a sixth switch solenoid valve 126. The second circuit control component 600 includes a seventh switch solenoid valve 127 and an eighth switch solenoid valve 128. The fifth switch solenoid valve 125 is respectively communicated with the second hydraulic branch 109 and the seventh hydraulic branch 120. The sixth switch solenoid valve 126 is respectively communicated with the first hydraulic branch 108 and the eighth hydraulic branch 121. The seventh switch solenoid valve 127 is respectively communicated with the third hydraulic branch 113 and the sixth hydraulic branch 116. The eighth switch solenoid valve 128 is respectively communicated with the fourth hydraulic branch 114 and the fifth hydraulic branch 115.

[0064] InFigure 1 Among them, the first circuit control normally closed valve 123 and the second circuit control normally closed valve 124 in the circuit control unit belong to reversing valves. The number is small, but the valve system is relatively complex.

[0065] In Figure 2 Among them, the fifth switching solenoid valve 125, the sixth switching solenoid valve 126, the seventh switching solenoid valve 127, and the eighth switching solenoid valve 128 in the circuit control unit belong to switching valves. Although the number increases, the valve block integration is easier.

[0066] As Figure 4 shown, the electronic control unit ECU (Electronic Control Unit) is respectively connected to each rebound adjustable damping valve, each compression adjustable damping valve, each switching solenoid valve, and each circuit control normally closed valve through signal lines to transmit control signals. The electronic control unit ECU is responsible for controlling and coordinating various electronic systems, including but not limited to the engine management system, automatic transmission control, anti-lock braking system (ABS), traction control, stability control, and adaptive or active suspension systems.

[0067] When the vehicle is in a non-roll state and a non-pitch state, that is, in a normal state, the first circuit control assembly 500 and the second circuit control assembly 600 are in a normally closed state.

[0068] Specifically, as Figure 1 and Figure 4 shown, the first switching solenoid valve 110, the second switching solenoid valve 111, the third switching solenoid valve 118, and the fourth switching solenoid valve 119 are all in an open state when not energized. The first circuit control normally closed valve 123 and the second circuit control normally closed valve 124 are in a normally closed state when not energized. The first hydraulic branch 108 is only connected to the second hydraulic branch 109. The third hydraulic branch 113 is only connected to the fourth hydraulic branch 114. The fifth hydraulic branch 115 is connected to the sixth hydraulic branch 116. The seventh hydraulic branch 120 is connected to the eighth hydraulic branch 121.

[0069] As Figure 1 and Figure 4 shown, when the vehicle is in a roll state or a pitch state, the first circuit control normally closed valve 123 and the second circuit control normally closed valve 124 are in an open state. The first hydraulic unit 100 is connected to the fourth hydraulic unit 400, and the second hydraulic unit 200 is connected to the third hydraulic unit 300, so that each hydraulic unit generates an upward or downward force on the vehicle body to prevent the suspension from rolling or pitching.

[0070] Specifically, when the vehicle is in a roll state or a pitch state, the first switching solenoid valve 110, the second switching solenoid valve 111, the third switching solenoid valve 118, and the fourth switching solenoid valve 119 are energized and in a closed state. The fifth switching solenoid valve 125, the sixth switching solenoid valve 126, the seventh switching solenoid valve 127, and the eighth switching solenoid valve 128 are open.

[0071] The first loop control normally closed valve 123 and the second loop control normally closed valve 124 are energized and in an open state. The first hydraulic branch 108 is only connected to the eighth hydraulic branch 121, the second hydraulic branch 109 is only connected to the seventh hydraulic branch 120, the third hydraulic branch 113 is only connected to the sixth hydraulic branch 116, and the fourth hydraulic branch 114 is only connected to the fifth hydraulic branch 115.

[0072] When the vehicle is in a roll state, the first actuator 210 and the third actuator 230 in the first hydraulic unit 100 and the third hydraulic unit 300 move downward respectively. The oil pressure difference between the upper and lower chambers of each actuator and the area difference between the upper chamber and the lower chamber increase, causing the first hydraulic unit 100 and the third hydraulic unit 300 to generate an upward force relative to the vehicle body. At the same time, the second actuator 220 and the fourth actuator 240 in the second hydraulic unit 200 and the fourth hydraulic unit 400 move upward respectively, and the oil pressure difference between the upper and lower chambers of each actuator increases, causing the second hydraulic unit 200 and the fourth hydraulic unit 400 to generate a downward force relative to the vehicle body. Under the combined action of the upward force and the downward force, an anti-roll moment is formed on the vehicle body.

[0073] Specifically, as Figure 1 and Figure 4 shown, when the vehicle is in a roll state, when the pistons of the first actuator 210 and the third actuator 230 move downward, the volume of the upper chambers 103 of the first actuator 210 and the third actuator 230 increases. The oil in the fourth accumulator 122 and the second accumulator 112 flows out and is replenished into the upper chambers 103 of the first actuator 210 and the third actuator 230. The oil pressure in the upper chambers 103 of the first actuator 210 and the third actuator 230 decreases. The volume of the lower chambers 105 of the first actuator 210 and the third actuator 230 decreases, and the oil in the lower chambers 105 of the first actuator 210 and the third actuator 230 flows out and enters the first accumulator 107 and the third accumulator 117. The oil pressure in the lower chambers 105 of the first actuator 210 and the third actuator 230 increases. Due to the oil pressure difference between the upper and lower chambers of the first actuator 210 and the third actuator 230 and the area difference between the upper chamber and the lower chamber, an upward force is generated on the vehicle body. At the same time, due to the oil pressure difference between the upper and lower chambers of the second actuator 220 and the fourth actuator 240, a downward force is generated on the vehicle body. An anti-roll moment is formed on the vehicle body, inhibiting the roll tendency of the vehicle, and the vehicle body tends to return to a normal state from the roll state.

[0074] When the vehicle is in a pitching state, as Figure 1 and Figure 4 shown, the first actuators 210 and 220 in the first hydraulic unit 100 and the second hydraulic unit 200 move downward respectively. The oil pressure difference between the upper and lower chambers of the first actuators 210 and 220 and the area difference between the upper chamber and the lower chamber increase, causing the first hydraulic unit 100 and the second hydraulic unit 200 to generate an upward acting force relative to the vehicle body. At the same time, the third actuators 230 and 240 in the third hydraulic unit 300 and the fourth hydraulic unit 400 move upward respectively. The oil pressure difference between the upper and lower chambers of the third actuators 230 and 240 increases, and the area difference between the upper chamber and the lower chamber increases, causing the third hydraulic unit 300 and the fourth hydraulic unit 400 to generate a downward acting force relative to the vehicle body. Under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-pitching moment.

[0075] Specifically, as Figure 1 and Figure 4 shown, when the pistons of the first actuators 210 and 220 move downward on an uneven road surface or during an emergency braking pitching tendency, the volume of the lower chambers 105 of the first actuators 210 and 220 decreases, and the oil flows out and enters the first accumulator 107 and the third accumulator 117. The oil pressure in the lower chambers 105 of the first actuators 210 and 220 increases, the volume of the upper chambers 103 of the first actuators 210 and 220 increases, and the oil in the first accumulator 107 and the third accumulator 117 flows out and replenishes the upper chambers 103 of the first actuators 210 and 220. The oil pressure in the upper chambers 103 of the first actuators 210 and 220 decreases. Due to the oil pressure difference between the upper and lower chambers of the first actuators 210 and 220 and the area difference between the upper chamber and the lower chamber, an upward acting force will be generated on the vehicle body. At the same time, due to the oil pressure difference between the upper and lower chambers of the third actuators 230 and 240 and the area difference between the upper chamber and the lower chamber, a downward acting force will be generated on the vehicle body, forming an anti-pitching moment on the vehicle body to suppress the pitching tendency of the vehicle, and the vehicle body tends to return to the normal state from the pitching state.

[0076] Apply the Figure 3 same type of actuators shown in Figure 2 to the active hydraulic interconnected suspension system in

[0077] When in a non-roll and non-pitch state, the first switch solenoid valve 110, the second switch solenoid valve 111, the third switch solenoid valve 118, and the fourth switch solenoid valve 119 are opened, and the fifth switch solenoid valve 125, the sixth switch solenoid valve 126, the seventh switch solenoid valve 127, and the eighth switch solenoid valve 128 are closed, so that the first hydraulic circuit 108 is communicated with the second hydraulic circuit 109, the third hydraulic branch 113 is communicated with the fourth hydraulic branch 114, the fifth hydraulic branch 115 is communicated with the sixth hydraulic branch 116, and the seventh hydraulic branch 120 is communicated with the eighth hydraulic branch 121.

[0078] When the vehicle's wheel passes over a bump, the piston in the first actuator 210 is compressed, and the hydraulic fluid in the lower chamber 105 of the first actuator 210 flows out and enters the compression valve main valve 505. The compression valve main valve 505 is provided with small holes and valve plates. The hydraulic fluid flows out through the small holes and the opened valve plates, generating throttling, forming a damping force, and attenuating vibrations. At the same time, the magnitude of the current of the compression adjustable valve 507 can be changed to change the size of the hydraulic fluid flowing out of the small holes and change the compression damping force value. A part of the hydraulic fluid flows back to the upper chamber 103 of the first actuator 210, and a part of the hydraulic fluid enters the accumulator 107.

[0079] When the vehicle's wheel passes over a pothole, the piston of the first actuator 210 is stretched, and the hydraulic fluid in the upper chamber 103 of the first actuator 210 flows out, passes through the oil passage 104 and enters the rebound valve main valve 502. The rebound valve main valve 502 has small holes and valve plates. The hydraulic fluid flows out through the small holes and the opened valve plates, generating throttling, forming a damping force, and attenuating vibrations. At the same time, the magnitude of the current of the rebound adjustable valve 503 can be changed to change the size of the hydraulic fluid flowing out of the small holes and change the rebound damping force value. A part of the hydraulic fluid enters the lower chamber 105 of the actuator. At the same time, the accumulator 107 has hydraulic fluid flowing out to supplement the lower chamber 105.

[0080] When the vehicle is in a roll and pitch state, the first switch solenoid valve 110, the second switch solenoid valve 111, the third switch solenoid valve 118, and the fourth switch solenoid valve 119 are closed. At this time, in Figure 2 the shown active hydraulic interconnected suspension system, the fifth switch solenoid valve 125, the sixth switch solenoid valve 126, the seventh switch solenoid valve 127, and the eighth switch solenoid valve 128 are opened. At this time, if in Figure 1 the shown active hydraulic interconnected suspension system, the first circuit control normally closed valve 123 and the second circuit control normally closed valve 124 are electrified and in an open state. The first hydraulic branch 108 is communicated with the eighth hydraulic branch 121, the second hydraulic branch 109 is communicated with the seventh hydraulic branch 120, the third hydraulic branch 113 is communicated with the sixth hydraulic branch 116, and the fourth hydraulic branch 114 is communicated with the fifth hydraulic branch 115.

[0081] When the vehicle turns, the pistons of the first actuator 210 and the third actuator 230 move downward, and the pistons of the second actuator 220 and the fourth actuator 240 move upward. The oil in the lower chamber of the first actuator 210 flows out, enters the main compression valve 505, and generates a damping force after flowing through the small hole and the valve plate. The oil in the upper chamber of the fourth actuator 240 flows out, enters the main rebound valve 502, and generates a damping force after flowing through the small hole and the valve plate. All the oil finally enters the accumulator 107 to attenuate the roll sway. The volumes of the upper chambers of the first actuator 210 and the lower chambers of the fourth actuator 240 increase, and the oil in the accumulator 122 flows out and enters the main rebound valve 502 of the upper chamber of the first actuator 230 and the main compression valve 505 of the lower chamber of the fourth actuator 340. The check valve on the main compression valve 505 opens, and the oil quickly flows back into the first actuator 210 and the fourth actuator 240 to replenish the oil in the corresponding actuators.

[0082] When the vehicle brakes, the pistons of the first actuator 210 and the second actuator 220 move downward, and the pistons of the third actuator 230 and the fourth actuator 240 move upward. The oil in the lower chamber of the first actuator 210 flows out and enters the chamber of the main compression valve 505, and generates a damping force after flowing through the small hole and the valve plate. The oil in the upper chamber of the fourth actuator 240 flows out and enters the chamber of the main rebound valve 502, and generates a damping force after flowing through the small hole and the valve plate. All the oil finally enters the accumulator 107 to attenuate the pitch vibration. The volumes of the upper chambers of the first actuator 210 and the lower chambers of the fourth actuator 240 increase, and the oil in the fourth accumulator 122 flows out and enters the chamber of the main rebound valve 502 of the upper chamber of the first actuator 21 and the chamber of the main compression valve 505 of the lower chamber of the fourth actuator 240. The check valve on the main rebound valve 502 opens, and the oil quickly flows back into the first actuator 210 and the fourth actuator 240 to replenish the oil in each actuator.

[0083] Meanwhile, the present invention can change the size of the small hole through which the oil flows out by changing the current magnitude of the compression adjustable valve 507, thereby changing the compression damping force value.

[0084] The present invention can also change the size of the small hole through which the oil flows out by changing the current magnitude of the rebound adjustable valve 503, thereby changing the rebound damping force value.

[0085] Embodiment 2

[0086] This embodiment is a further improvement of Embodiment 1, and the repeated content will not be elaborated.

[0087] This embodiment provides a control method for an active hydraulically interconnected suspension system, as Figure 5 shown.

[0088] S1: In the initial state of the system, the electronic control unit ECU controls each switch solenoid valve to be in the first state, that is, in the normally open state.

[0089] S2: Obtain vehicle speed signal, vehicle body acceleration signal and steering wheel angle signal.

[0090] The electronic control unit ECU obtains the vehicle speed signal, vehicle body acceleration signal and steering wheel angle signal through various sensors of the vehicle's speed measurement system.

[0091] S3: Identify vehicle stiffness, damping and mass parameters.

[0092] The electronic control unit ECU receives the original signals collected by the sensors, and performs signal processing and filtering to eliminate noise and interference and extract useful information.

[0093] The electronic control unit ECU analyzes and calculates the processed sensor data to estimate the vehicle's stiffness, damping and mass parameters. Stiffness refers to the degree of elastic deformation of the suspension system when subjected to a certain force; damping refers to the degree of energy dissipation of the suspension system during vibration; the mass parameter refers to the total mass and distribution of the vehicle.

[0094] S4: Evaluate the main mode of the vehicle at this time according to the proportion of the modal energy method.

[0095] The steps for the electronic control unit ECU to judge the main mode include steps S41 to S43.

[0096] S41: Determine the energy distribution of different modes based on the modal energy method.

[0097] The modal energy method (Motion-mode Energy Method, MEM) is a method for analyzing the motion modal energy of a vehicle based on linear modal theory. This method can calculate and analyze the energy of each motion mode of an object in real time. The kinetic energy and potential energy of the vehicle in a certain motion mode can be calculated in real time through the displacement, speed, mass, mass moment of inertia, stiffness, etc. of the vehicle in this motion mode. The sum of the kinetic energy and potential energy of the motion mode is defined as the modal energy in this motion mode. The ratio of the modal energy in this motion mode to the sum of all modal energies is called the modal energy ratio. By comparing the motion modal energies and energy ratios in each motion mode, the contribution of each motion mode to the vehicle motion can be understood.

[0098] For a two - axis four - wheel seven - degree - of - freedom vehicle model, there are seven motion modes named according to their modal vibration modes. According to whether the body or the wheels play a dominant role in the modal vibration mode, the motion modes can be further divided into body - dominated motion modes and wheel - dominated motion modes. Generally, according to the order of the vehicle's natural frequencies, the body motion modes dominate in the first three motion modes, and the wheel motion modes dominate in the last four motion modes. The energy of the motion modes can be measured during the vehicle's motion, and the calculation units in the measurement and calculation process must be the same for comparison. The kinetic energy in the motion modes is regarded as a scalar that can be compared among different motion modes. The method of measuring the energy of the motion modes in real - time is called the modal energy method. The motion of the vehicle in each state is a modal superposition of the vehicle state vector. The physical motion of the vehicle in three - dimensional coordinates is converted into seven motion modes in seven - dimensional coordinates, and each motion mode in this seven - dimensional coordinate has a vector component in the form of velocity and displacement. The vector component represents the ratio of this motion mode in the total motion modes of the vehicle.

[0099] The energy in one motion mode will not be exchanged with other motion modes. Its energy will only be continuously converted between the kinetic energy and potential energy of this motion mode, and finally will decrease to zero due to the action of damping. In this way, according to the transfer of energy, the motion of the vehicle can be decoupled into seven motion modes, and their energies can be calculated.

[0100] On the basis of determining the energy distribution, the electronic control unit ECU determines the vehicle vibration mode according to the modal frequency and modal form.

[0101] S42: Conduct modal frequency analysis.

[0102] Modal frequency: Each mode has a specific natural frequency. Through spectrum analysis, it can be determined which frequency corresponds to the main mode.

[0103] Usually, the pitch mode, roll mode, and vertical mode have different natural frequencies. For example, the frequency of the pitch mode is usually lower, while the frequency of the vertical mode is higher.

[0104] S43: Conduct modal shape analysis.

[0105] Modal shape: The modal shape describes the deformation mode of the vehicle during vibration and can be obtained through finite element analysis (FEA) simulation or other experimental methods.

[0106] Preferably, the storage module connected to the electronic control unit ECU stores the deformation sample data of the vehicle during vibration in each mode. The deformation sample data during vibration in each mode is real data obtained by installing the active hydraulic interconnected suspension system of the present invention on various vehicle suspensions and through a large number of experiments.

[0107] The electronic control unit ECU compares the deformation data of the main mode during vibration with the deformation sample data in the storage module, and selects the mode associated with the deformation sample data with a matching degree greater than 90% as the vibration mode.

[0108] For example, the mode shape of the pitch mode shows a relatively large relative displacement between the front and rear ends of the vehicle; the mode shape of the roll mode shows a relatively large relative displacement between the left and right sides of the vehicle; the mode shape of the vertical mode shows a relatively large vertical displacement of the entire vehicle.

[0109] Preferably, the association relationships between each mode and the mode frequency and mode shape are stored in tabular form. After determining the energy distribution of the current mode of the vehicle, inputting the mode frequency and mode shape of the main mode with an energy distribution ratio of 60% into the table can select the corresponding vibration mode.

[0110] More preferably, inputting the mode frequency and mode shape of the main mode with an energy distribution ratio of 60% into the table, in the case where there is no exactly matching data, select the mode with a mode frequency difference less than the difference threshold and a mode shape similarity greater than the similarity threshold as the vibration mode. The difference threshold is 5 - 10%. The similarity threshold is 5 - 10%.

[0111] Such an evaluation step can help the electronic control unit ECU identify the most important modes in the vehicle vibration system for corresponding control and adjustment. The ECU can optimize the control strategy of the suspension system according to the energy proportion of the main mode to reduce the influence of the main mode vibration and improve the handling performance and riding comfort of the vehicle.

[0112] For example, the steps of one method for determining the vibration mode are as follows. The following content is only an example and does not represent the only implementation method.

[0113] S411: Data collection and preprocessing.

[0114] Install sensors: Install accelerometers and displacement sensors at key parts of the vehicle to collect vibration data.

[0115] Data synchronization: Ensure the time synchronization of all sensor data for accurate modal analysis.

[0116] S412: Application of the modal energy method.

[0117] Use the modal energy method to analyze the collected data to determine the energy distribution of each mode. For example, if the energy proportion of the main mode is 60%, then the energy proportion of the secondary mode is 40%.

[0118] S413: Modal frequency and shape analysis.

[0119] Spectrum analysis: Determine the natural frequencies of each mode through spectrum analysis.

[0120] Modal shape acquisition: Use FEA or other experimental methods to obtain modal shape data and store it in the storage module of the electronic control unit (ECU).

[0121] S414: Modal matching and selection.

[0122] Data comparison: Compare the measured modal deformation data with the tabular sample data in the storage module.

[0123] Select mode: Select the mode with a matching degree greater than 90% as the current vibration mode. If there is no completely matching mode, select the mode with a modal frequency difference less than 10% and a modal shape similarity greater than 10%.

[0124] S415: Control strategy optimization.

[0125] According to the identified main mode, adjust the control parameters of the suspension system, such as damping force and spring stiffness, to reduce the vibration influence of the main mode.

[0126] Implement control strategy: The electronic control unit (ECU) adjusts the suspension system in real time according to the optimized parameters to improve the vehicle's handling performance and ride comfort.

[0127] S416: Result verification.

[0128] After implementing the above control strategy, verify the control effect by collecting and analyzing vibration data again. Compare the data before and after implementation, evaluate the effectiveness of the control strategy, and make further adjustments if necessary.

[0129] S5: If the pitch mode or roll mode is the main mode and the acceleration exceeds the threshold, switch the solenoid valve from the first state to the second state.

[0130] When the vehicle is in a rolling state, the first actuators 210 and 230 in the first hydraulic unit 100 and the third hydraulic unit 300 move downward respectively, and the oil pressure difference between the upper and lower chambers of each actuator increases, causing the first hydraulic unit 100 and the third hydraulic unit 300 to generate an upward force relative to the vehicle body. At the same time, the second actuators 220 and 240 in the second hydraulic unit 200 and the fourth hydraulic unit 400 move upward respectively, and the oil pressure difference between the upper and lower chambers of each actuator increases and the area difference between the upper chamber and the lower chamber, causing the second hydraulic unit 200 and the fourth hydraulic unit 400 to generate a downward force relative to the vehicle body. Under the combined action of the upward force and the downward force, the vehicle body forms an anti-roll moment.

[0131] When the vehicle is in a pitching state, the first actuator 210 and the second actuator 220 in the first hydraulic unit 100 and the second hydraulic unit 200 move downward respectively, and the oil pressure difference between the upper and lower chambers of each actuator increases, causing the first hydraulic unit 100 and the second hydraulic unit 200 to generate an upward acting force relative to the vehicle body. At the same time, the third actuator 230 and the fourth actuator 240 in the third hydraulic unit 300 and the fourth hydraulic unit 400 move upward respectively, and the oil pressure difference between the upper and lower chambers of each actuator and the difference between the area of the upper chamber and the area of the lower chamber increase, causing the third hydraulic unit 300 and the fourth hydraulic unit 400 to generate a downward acting force relative to the vehicle body. Under the combined action of the upward acting force and the downward acting force, the vehicle body forms an anti-pitching moment.

[0132] S6: If the vertical mode is the main mode, maintain the state of the switch solenoid valve as the first state, that is, maintain the normally open state.

[0133] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also fall within the scope of the disclosure of the present invention and within the protection scope of the present invention. Those skilled in the art should understand that the specification and drawings of the present invention are illustrative and do not constitute a limitation on the claims. The protection scope of the present invention is defined by the claims and their equivalents. The specification of the present invention contains multiple inventive concepts. Phrases such as "preferably", "according to a preferred embodiment", or "optionally" indicate that the corresponding paragraphs disclose an independent inventive concept. The applicant reserves the right to file divisional applications based on each inventive concept.

Claims

1. An active hydraulic interconnected suspension system, comprising a plurality of hydraulic units and a circuit control unit, characterized in that: The loop control unit comprises a first loop control component (500) and a second loop control component (600), The first hydraulic unit (100) is connected to the first circuit control component (500) through the first hydraulic branch (108) and the second hydraulic branch (109), respectively. The second hydraulic unit (200) is connected to the second circuit control component (600) through the third hydraulic branch (113) and the fourth hydraulic branch (114), respectively. The third hydraulic unit (300) is connected to the second circuit control component (600) via the fifth hydraulic branch (115) and the sixth hydraulic branch (116), respectively. The fourth hydraulic unit (400) is connected to the first circuit control component (500) via the seventh hydraulic branch (120) and the eighth hydraulic branch (121), respectively. Wherein, the first hydraulic unit (100) and the second hydraulic unit (200) are symmetrically arranged on both sides of the suspension, and the third hydraulic unit (300) and the fourth hydraulic unit (400) are symmetrically arranged on both sides of the suspension; Furthermore, the first hydraulic unit (100) and the third hydraulic unit (300) are arranged on the same side, and the second hydraulic unit (200) and the fourth hydraulic unit (400) are arranged on the same side.

2. The active hydraulic interconnected suspension system according to claim 1, characterized in that: The hydraulic unit includes an actuator, a return adjustable damping valve, a compression adjustable damping valve, an accumulator and a switch solenoid valve. The upper chamber (103) of the actuator is connected to the return adjustable damping valve, the lower chamber (105) of the actuator is connected to the compression adjustable damping valve, and the return adjustable damping valve is in communication with the compression adjustable damping valve. The compression adjustable damping valve is connected to the accumulator, A switch solenoid valve is arranged between the hydraulic branch connected to the return adjustable damping valve and the hydraulic branch connected to the accumulator.

3. The active hydraulic interconnected suspension system according to claim 1 or 2, characterized in that: When the vehicle is in a non-rolling state and a non-pitch state, the first loop control component (500) and the second loop control component (600) are in a normally closed state; When the vehicle is in a roll state or a pitch state, the first circuit control component (500) and the second circuit control component (600) are in an open state, the first hydraulic unit (100) is connected to the fourth hydraulic unit (400), and the second hydraulic unit (200) is connected to the third hydraulic unit (300), so that each hydraulic unit generates an upward or downward force on the vehicle body to prevent the suspension from rolling or pitching.

4. The active hydraulic interconnected suspension system according to claim 3, characterized in that: The first circuit control component (500) includes a first circuit control normally closed valve (123), and the second circuit control component (600) includes a second circuit control normally closed valve (124). The first circuit control normally closed valve (123) is respectively connected to the first hydraulic branch (108), the second hydraulic branch (109), the seventh hydraulic branch (120) and the eighth hydraulic branch (121); The second circuit control normally closed valve (124) is respectively connected to the third hydraulic branch (113), the fourth hydraulic branch (114), the fifth hydraulic branch (115) and the sixth hydraulic branch (116).

5. The active hydraulic interconnected suspension system according to claim 3, characterized in that: The first circuit control component (500) includes a fifth switch solenoid valve (125) and a sixth switch solenoid valve (126), and the second circuit control component (600) includes a seventh switch solenoid valve (127) and an eighth switch solenoid valve (128). The fifth switch solenoid valve (125) is respectively connected to the second hydraulic branch (109) and the seventh hydraulic branch (120); The sixth switch solenoid valve (126) is respectively connected to the first hydraulic branch (108) and the eighth hydraulic branch (121); The seventh switch solenoid valve (127) is respectively connected to the third hydraulic branch (113) and the sixth hydraulic branch (116); The eighth switch solenoid valve (128) is communicated with the fourth hydraulic branch (114) and the fifth hydraulic branch (115) respectively.

6. The active hydraulic interconnected suspension system according to any one of claims 1 to 5, characterized in that: When the vehicle is in a roll state, The actuators in the first hydraulic unit (100) and the third hydraulic unit (300) move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the first hydraulic unit (100) and the third hydraulic unit (300) generate an upward force relative to the vehicle body. At the same time, the actuators in the second hydraulic unit (200) and the fourth hydraulic unit (400) move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the second hydraulic unit (200) and the fourth hydraulic unit (400) generate a downward force relative to the vehicle body. Under the combined effect of the upward force and the downward force, the vehicle body forms an anti-roll moment.

7. The active hydraulic interconnected suspension system according to any one of claims 1 to 6, characterized in that: When the vehicle is in a pitching state, The actuators in the first hydraulic unit (100) and the second hydraulic unit (200) move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the first hydraulic unit (100) and the second hydraulic unit (200) generate an upward force relative to the vehicle body. At the same time, the actuators in the third hydraulic unit (300) and the fourth hydraulic unit (400) move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the third hydraulic unit (300) and the fourth hydraulic unit (400) generate a downward force relative to the vehicle body. Under the combined effect of the upward force and the downward force, the vehicle body forms an anti-pitch moment.

8. A control method for an active hydraulic interconnected suspension system, characterized in that: The method comprises: when the vehicle is in a non-rolling state and a non-pitch state, the first loop control component (500) and the second loop control component (600) are in a normally closed state; When the vehicle is in a roll state or a pitch state, the first circuit control component (500) and the second circuit control component (600) are in an open state, the first hydraulic unit (100) is connected to the fourth hydraulic unit (400), and the second hydraulic unit (200) is connected to the third hydraulic unit (300), so that each hydraulic unit generates an upward or downward force on the vehicle body to prevent the suspension from rolling or pitching; The active hydraulic interconnected suspension system comprises a plurality of hydraulic units and a circuit control unit, wherein the circuit control unit comprises a first circuit control component (500) and a second circuit control component (600). The first hydraulic unit (100) is connected to the first circuit control component (500) through the first hydraulic branch (108) and the second hydraulic branch (109), respectively. The second hydraulic unit (200) is connected to the second circuit control component (600) through the third hydraulic branch (113) and the fourth hydraulic branch (114), respectively. The third hydraulic unit (300) is connected to the second circuit control component (600) via the fifth hydraulic branch (115) and the sixth hydraulic branch (116), respectively. The fourth hydraulic unit (400) is connected to the first circuit control component (500) via the seventh hydraulic branch (120) and the eighth hydraulic branch (121), respectively. The first hydraulic unit (100) and the second hydraulic unit (200) are symmetrically arranged on both sides of the suspension, and the third hydraulic unit (300) and the fourth hydraulic unit (400) are symmetrically arranged on both sides of the suspension; Furthermore, the first hydraulic unit (100) and the third hydraulic unit (300) are arranged on the same side, and the second hydraulic unit (200) and the fourth hydraulic unit (400) are arranged on the same side.

9. The control method of the active hydraulic interconnected suspension system according to claim 8, characterized in that: The method further comprises: When the vehicle is in a roll state, The actuators in the first hydraulic unit (100) and the third hydraulic unit (300) are controlled to move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the first hydraulic unit (100) and the third hydraulic unit (300) generate an upward force relative to the vehicle body. At the same time, the actuators in the second hydraulic unit (200) and the fourth hydraulic unit (400) are controlled to move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the second hydraulic unit (200) and the fourth hydraulic unit (400) generate a downward force relative to the vehicle body. Under the combined effect of the upward force and the downward force, the vehicle body forms an anti-roll moment.

10. The control method of the active hydraulic interconnected suspension system according to claim 8 or 9, characterized in that: The method further comprises: When the vehicle is in a pitching state, The actuators in the first hydraulic unit (100) and the second hydraulic unit (200) are controlled to move downward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the first hydraulic unit (100) and the second hydraulic unit (200) generate an upward force relative to the vehicle body. At the same time, the actuators in the third hydraulic unit (300) and the fourth hydraulic unit (400) are controlled to move upward respectively, and the oil pressure difference between the upper and lower chambers of the actuators increases, so that the third hydraulic unit (300) and the fourth hydraulic unit (400) generate a downward force relative to the vehicle body. Under the combined effect of the upward force and the downward force, the vehicle body forms an anti-pitch moment.

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