Multi-mode servo suspension system of high-rigidity wheeled vehicle and regulation and control method

Abstract

The invention provides a multi-mode servo suspension system suitable for a high-rigidity wheeled vehicle of a new energy automobile and a regulation and control method, and relates to the technical field of multi-mode suspensions.The system comprises a chassis, a suspension structure connected to the chassis and wheels connected to the suspension structure, and the suspension structure comprises a hydraulic actuator, a hydraulic control system and a servo control system; an inerter assembly and a hydraulic oil path system; two damping oil ways are further connected between the two-position three-way valves in the two hydraulic oil ways, and a variable damper and a pneumatic one-way valve are connected in each damping oil way. A pneumatic system; and a control system. Quick switching of the suspension system in passive, semi-active and active modes is achieved by adjusting the valve position and the on-off condition of the hydraulic element and adjusting the damping of the variable damper, and the control system can preview elevation information of a road surface, vehicle body posture information and a vehicle running state and feed back the information to the central controller, so that the control system can control the vehicle running state. And a proper suspension mode is selected, so that the all-road-condition working performance of the suspension system is further improved.

Description

Technical Field

[0001] This invention relates to the field of multimodal suspension technology for new energy vehicles, specifically to a multimodal servo suspension system and control method for high-rigidity wheeled vehicles. Background Technology

[0002] With the increasing development and growing usage of new energy vehicles, people's demands for them are no longer limited to environmental protection, energy conservation, and low operating costs. They are also gradually pursuing a higher quality driving experience, greater ride comfort, and longer vehicle lifespan. Research has found that the battery life of new energy vehicles is closely related to the vehicle's driving stability and shock absorption performance.

[0003] While traditional pneumatic tires offer ride comfort, they also negatively impact driving safety and handling stability. According to traffic management statistics, most tire-related traffic accidents are related to driving with low tire pressure or tire blowouts. Furthermore, due to limitations in tire pressure and tire contact patch characteristics, pneumatic tires have limited load-bearing capacity, making them prone to blowouts when overloaded. Therefore, in military and special transport applications, pneumatic tires are rarely used in frontline operations, with tracked vehicles being more commonly employed. However, tracked vehicles lack flexibility, affecting their mobility. To balance flexibility and blowout resistance, research into high-rigidity wheels has been continuously deepening. In recent years, with advancements in the automotive industry, more and more vehicles are adopting wheels with higher rigidity, such as solid, non-pneumatic wheels. These wheels combine blowout resistance with the flexibility of wheeled vehicles, attracting widespread attention.

[0004] However, high-rigidity wheels have significantly higher tire stiffness than traditional pneumatic tires, resulting in more direct vibration transmission when exposed to road impacts and thus increased vehicle vibration. Traditional suspension systems are difficult to adapt effectively to high-rigidity wheels, limiting their further application. Therefore, developing high-performance suspension systems is crucial for promoting the widespread adoption of high-rigidity wheels.

[0005] The automotive suspension system is a core component affecting ride comfort and handling performance. Existing suspension systems are mainly divided into three categories: passive suspension, semi-active suspension, and active suspension. Active suspension actively outputs force through hydraulic actuators, effectively isolating road vibrations and possessing optimal damping performance. However, it suffers from high energy consumption, limited response speed, and difficulty in continuously adapting to high-load conditions, limiting its application. Semi-active suspension mitigates vibration transmission by adjusting damping force, balancing comfort and handling. However, it requires high reliability from variable damping elements and has limited damping effect under harsh road conditions, thus not yet being widely adopted. Passive suspension has a simple structure and low cost, but its fixed damping parameters make it difficult to adapt to extreme conditions, restricting vehicle safety and handling performance. In summary, existing suspension systems still have many shortcomings, further hindering the widespread application of high-rigidity wheels.

[0006] In particular, existing vehicles generally use a single type of suspension system, and each type of suspension has obvious shortcomings. Lower-end models mostly use passive suspension, while some high-end models offer semi-active suspension, but their damping performance is still insufficient; active suspension has not yet achieved large-scale vehicle application. Currently, there is a lack of a system solution integrating three suspension modes, thus failing to fully adapt to the diverse damping requirements of high-rigidity wheeled vehicles in various driving scenarios. Furthermore, there is a lack of effective methods to coordinate multiple suspension modes for rapid switching and scenario adaptation; in addition, existing systems have not systematically evaluated the applicability boundaries of various suspension modes, limiting their vehicle performance. Summary of the Invention

[0007] To address the shortcomings of the prior art, the present invention aims to provide a multimodal servo suspension system and control method for high-rigidity wheeled vehicles. This system enables rapid switching between passive, semi-active, and active modes of the suspension system, and switches to the appropriate suspension mode based on vehicle driving information. This solves the problem that a single type of suspension in the prior art cannot adapt to the vibration reduction requirements of diverse driving scenarios.

[0008] Specifically, on one hand, the present invention provides a multimodal servo suspension system for high-rigidity wheeled vehicles suitable for new energy vehicles, comprising a chassis, a suspension structure connected to the chassis, and a plurality of wheels connected to the suspension structure, wherein the suspension structure includes: Hydraulic actuator: Its top is fixed to the chassis, and its bottom is rotatably mounted on the connecting structure for connecting the chassis and the wheels; Inertia container assembly: It includes an upper spring, an inertia container and a lower spring, which are sleeved on the outside of the hydraulic actuator. The inertia container is located between the upper spring and the lower spring and can float up and down. Hydraulic circuit system: It is mounted on the chassis and includes an oil tank, a hydraulic pump connected to the oil tank, a hydraulic valve block connected to the hydraulic pump, and a first accumulator connected to the hydraulic valve block. The hydraulic valve block is also connected to a servo valve, which connects to two hydraulic circuits. Both hydraulic circuits include a two-position two-way valve and a two-position three-way valve, and both hydraulic circuits are connected to a hydraulic actuator. One of the circuits is connected to a second accumulator, which contains a liquid chamber and a gas chamber, as well as an elastic diaphragm to separate the liquid chamber and the gas chamber. The two-position three-way valves in the two hydraulic circuits are also connected to two damping circuits, each of which is connected to a variable damper and a branch check valve. Pneumatic system: It is mounted on the chassis and connected to the second accumulator to provide air pressure to the gas chamber of the second accumulator; Control system: It is mounted on the chassis and includes a central controller, a road surface advance sensor and a vehicle attitude sensor that are electrically connected to the central controller. The road surface advance sensor is located at the front of the chassis bottom to collect the elevation information of the road surface ahead. The central controller is also electrically connected to the hydraulic system and the pneumatic system, and realizes the switching between passive mode, semi-active mode and active mode of the vehicle by controlling the hydraulic system and the pneumatic system.

[0009] Furthermore: the pneumatic system includes an air pump and a pneumatic valve block connected to the air pump. The pneumatic valve block is connected to several pneumatic branches. Each pneumatic branch is equipped with an adjustable pressure relief valve. The first end of the adjustable pressure relief valve is connected to the pneumatic valve block through a pneumatic check valve, and the second end is connected to the gas chamber of the second accumulator.

[0010] Furthermore, the hydraulic circuit system also includes a relief valve, a hydraulic filter, and a main line check valve. The hydraulic pump is connected to the hydraulic valve block through the hydraulic filter and the main line check valve. The first end of the relief valve is connected to the pipeline between the hydraulic pump and the hydraulic filter, and the second end is connected to the oil tank.

[0011] Furthermore: the suspension structure includes a front control arm for connecting the front wheels to the chassis and a rear axle for connecting the rear wheels to the chassis; wherein, there are two sets of front control arms, which are fixedly installed on both sides of the chassis respectively, and each set of front control arms is equipped with a hydraulic actuator, and the rear axle is equipped with two hydraulic actuators.

[0012] Furthermore: The hydraulic actuator inside the inertial container assembly on the rear axle is replaced with a telescopic rod. The top of the telescopic rod is fixedly connected to the chassis, and the bottom is fixedly installed on the rear axle. The top of the hydraulic actuator on the rear axle is fixedly connected to the chassis, and the bottom is rotatably installed on the rear axle.

[0013] The present invention also provides a method for controlling a multimodal servo suspension system for a high-rigidity wheeled vehicle, comprising the following steps: S1: Initialize the suspension system and data acquisition: The central controller controls the hydraulic pump to continuously supply oil to the first accumulator until the internal pressure of the first accumulator reaches the set threshold. If the internal pressure does not reach the set threshold, the hydraulic pump continues to supply oil to replenish the pressure. The road surface pre-aiming sensor collects road surface elevation information and obtains the chassis ground clearance, while the vehicle body attitude sensor obtains vehicle body attitude information. S2: The central controller receives the collected road surface elevation information, chassis ground clearance information, and vehicle posture information, and obtains basic vehicle data information and vehicle driving status information. S3: Calculate the ground clearance suitable for vehicle driving based on the information obtained in S2 and select the suspension mode. Control the pneumatic system to change the air pressure inside the gas chamber of the second accumulator, and then adjust the ground clearance of the chassis through the hydraulic actuator. The suspension modes include: passive mode, semi-active mode, and active mode; the central controller controls the hydraulic and pneumatic systems to put the vehicle into the corresponding suspension mode. S4: During vehicle operation, the central controller monitors whether there is a sudden change in the vehicle's driving status. If a sudden change occurs, the central controller controls the vehicle to enter active mode. S5: After entering active mode, if the vehicle's driving status does not change suddenly within the set time, then continue to execute S2; S6: After completing the driving, the suspension system enters the termination procedure.

[0014] Furthermore: The steps to enable passive mode include: Based on the vehicle's basic data, chassis ground clearance, and vehicle driving status, the fixed damping values ​​of the compression and rebound circuits of each hydraulic actuator are determined. The central controller converts the damping values ​​of the compression and rebound circuits of each hydraulic actuator into control signals for the variable damper and sets a fixed output.

[0015] Furthermore, the steps to activate semi-active mode include: The central controller combines vehicle driving status information, road elevation information, and vehicle dynamics data, and also incorporates the seven-degree-of-freedom dynamics formula of the whole vehicle with variable damping suspension. The vehicle dynamics data is substituted into the formula and solved inversely to calculate the damping value corresponding to each hydraulic actuator. The central controller converts the damping value of each hydraulic actuator into a control signal for the variable damper, thereby enabling continuous adjustment of the damping value of each hydraulic actuator.

[0016] Furthermore: The steps to activate active mode include: The central controller combines vehicle driving status information, road elevation information, and vehicle body posture information, and, based on the relationship between the vehicle body posture information and the kinematics of the vehicle suspension, calculates the extension and retraction of each hydraulic actuator. The extension / retraction amount of each hydraulic actuator is used as the reference signal for the servo valve to control each hydraulic actuator, and the actual extension / retraction displacement of each hydraulic actuator is used as the output signal. The central controller calculates and outputs the control signal of the servo valve through an improved error-tracking model-free adaptive control algorithm, thereby realizing closed-loop control of each hydraulic actuator. Indicates the first Servo valve control signal at all times Indicates the first The actual extension and retraction displacement of the hydraulic actuator at all times. Indicates the first Reference signal at time, Indicates the first Servo valve control signal at all times Indicates the first The actual extension and retraction displacement of the hydraulic actuator at all times. Indicates the first Reference signal at time; ; in, These are the weighting coefficients. Step size factor As a weighting factor, As a weighting factor, It is the first step in the actual control process Time-varying parameters at time t, It is the first Time-varying parameters at time t, yes The estimated value, for The estimated value, The time-varying weighting coefficients and the algorithm for estimating the time-varying parameters are as follows: ; in, This represents the actual change in extension and retraction displacement of the hydraulic actuator at adjacent time points. ; To enhance the estimation algorithm's ability to track time-varying parameters, reset conditions are designed: ,when or or ; in, Indicates the step size coefficient. It is a very small positive number. yes The initial value.

[0017] Furthermore: After activating the active mode, the hydraulic pump is no longer limited by the set threshold of the internal pressure of the first accumulator and continues to work to supply oil to the suspension system.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The multi-modal servo suspension system for high-rigidity wheeled vehicles disclosed in this invention achieves rapid switching between passive, semi-active, and active modes by adjusting the valve positions and on / off states of hydraulic components such as two-position two-way valves, two-position three-way valves, and servo valves, combined with adjusting the damping magnitude of the variable damper. Simultaneously, a control system is also included. This control system can anticipate road elevation information, vehicle posture information, and vehicle driving status, and feed this information back to the central controller to select the appropriate suspension mode. This further enhances the all-road performance of the suspension system, thereby meeting the vibration reduction requirements of high-rigidity wheeled vehicles in different driving scenarios, thus improving the driving experience and ride comfort. Especially when applied to new energy vehicles, the higher quality vibration reduction effect can extend battery life.

[0019] 2. The multi-modal servo suspension system for high-rigidity wheeled vehicles disclosed in this invention configures two suspension springs with different stiffnesses and installs an inertia container between the two suspension springs. At the same time, it uses a second accumulator to couple the pneumatic system with the hydraulic system, ensuring that the suspension system has both excellent vehicle load-bearing capacity and flexible ground clearance, and can effectively filter out the transmission of medium and high frequency vibrations caused by road surface excitation during driving.

[0020] 3. The multimodal servo suspension system for high-rigidity wheeled vehicles disclosed in this invention collects vehicle posture data through vehicle attitude sensors and, based on the dynamic relationship between the suspension and the vehicle body, provides feedback control over the extension and contraction of hydraulic actuators in active mode and the damping of hydraulic actuators in semi-active mode, thereby achieving precise control of the suspension system in active and semi-active modes. Simultaneously, the central controller monitors changes in vehicle body data in real time to determine if there are sudden changes in vehicle stability. Once a sudden change is detected, the system automatically switches to active mode, actively outputting actuators to enhance vehicle handling and stability under sudden conditions, thereby ensuring vehicle driving safety. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention; Figure 2 This is a schematic diagram of the servo suspension system structure excluding the chassis in the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention. Figure 3 This is a schematic diagram of the hydraulic branch system in the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention. Figure 4 This is a schematic diagram of the hydraulic pump in the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention; Figure 5This is a schematic diagram of the rear axle structure in the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention; Figure 6 This is a schematic diagram of the pneumatic system in the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention; Figure 7 This is a schematic diagram of the hydraulic control principle of the multimodal servo suspension system for high-rigidity wheeled vehicles of the present invention; Figure 8 This is a schematic diagram of the overall operation flow of the control method for the multimodal servo suspension system of the high-rigidity wheeled vehicle of the present invention. Figure 9 This is a schematic diagram of the operation flow of a preferred embodiment of the control method for the multimodal servo suspension system of a high-rigidity wheeled vehicle of the present invention.

[0022] In the attached drawings, the following reference numerals are used: 1. Wheel; 2. Front control arm; 3. Chassis; 4. Hydraulic actuator; 401. Front upper suspension spring; 402. Front suspension inertia container; 403. Front lower suspension spring; 404. Front hydraulic actuator; 5. Hydraulic circuit system; 501. Oil tank; 502. Hydraulic pump; 503. Relief valve; 504. Hydraulic filter; 505. Main circuit check valve; 506. Hydraulic valve block; 507. First accumulator; 508. Servo valve; 509. Two-position two-way valve; 510. Two-position three-way valve. 511. Valve; 512. Variable damper; 513. Branch check valve; 514. Second accumulator; 6. Pneumatic system; 601. Air pump; 602. Pneumatic check valve; 603. Pneumatic valve block; 604. Adjustable pressure relief valve; 7. Rear axle; 8. Telescopic rod; 801. Rear wheel upper suspension spring; 802. Rear wheel suspension inertia container; 803. Rear wheel lower suspension spring; 9. Rear wheel hydraulic actuator; 10. Control system; 1001. Road surface pre-aiming sensor; 1002. Vehicle body attitude sensor; 1003. Central controller. Detailed Implementation

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] like Figure 1 and Figure 2 As shown, this invention provides a preferred embodiment of a multimodal servo suspension system for high-rigidity wheeled vehicles suitable for new energy vehicles. The system includes wheels 1, a chassis 3, two front control arms 2 connecting the front wheels 1 to the chassis 3, and a rear axle 7 connecting the rear wheels 1 to the chassis 3. A hydraulic actuator 4 is fixedly connected to the chassis 3. The hydraulic actuator 4 includes a front wheel hydraulic actuator 404 and a rear wheel hydraulic actuator 9. The top of the front wheel hydraulic actuator 404 is fixedly connected to the chassis 3, and its bottom is rotatably mounted on the front control arms 2. The top of the rear wheel hydraulic actuator 9 is fixedly connected to the chassis 3, and its bottom is rotatably mounted on the rear axle 7. The wheels 1 are high-rigidity wheels.

[0025] like Figure 3 As shown, the system also includes an inertia container assembly, which includes a front wheel suspension inertia container assembly and a rear wheel suspension inertia container assembly. The front wheel suspension inertia container assembly includes a front wheel suspension inertia container 402 disposed outside the front wheel hydraulic actuator 404. The upper and lower parts of the front wheel suspension inertia container 402 are respectively provided with a front wheel upper suspension spring 401 and a front wheel lower suspension spring 403. The front wheel suspension inertia container 402 can float up and down between the front wheel upper suspension spring 401 and the front wheel lower suspension spring 403.

[0026] like Figure 5 As shown, the rear wheel suspension inertia container assembly includes a rear wheel suspension inertia container 802 disposed outside the telescopic rod 8. The upper and lower parts of the rear wheel suspension inertia container 802 are respectively provided with an upper rear wheel suspension spring 801 and a lower rear wheel suspension spring 803. The rear wheel suspension inertia container 802 can float up and down between the upper rear wheel suspension spring 801 and the lower rear wheel suspension spring 802. The bottom of the telescopic rod 8 is fixedly mounted on the rear axle 7, and the top is fixedly connected to the chassis 3. The reason why the hydraulic actuators, suspension inertia container assembly, and other structures at the rear wheels are slightly different from those at the front wheels is mainly to adapt to the mainstream automotive structures currently on the market.

[0027] Combination Figure 4 , Figure 6 and Figure 7 As shown, the system also includes a hydraulic circuit system 5 and a pneumatic system 6, both of which are mounted on the chassis 3.

[0028] The hydraulic circuit system 5 includes an oil tank 501, a hydraulic pump 502 connected to the oil tank, a hydraulic filter 504 connected to the hydraulic pump 502, a main line check valve 505 connected to the hydraulic filter 504, a hydraulic valve block 506 connected to the main line check valve 505, and a first accumulator 507 connected to the hydraulic valve block 506. An overflow valve 503 is connected to the pipeline between the hydraulic pump 502 and the hydraulic filter 504. The other end of the overflow valve 503 is connected to the oil tank 501 to return excess oil to the oil tank 501.

[0029] The hydraulic valve block 506 is also connected to the servo valve 508, which is connected to two hydraulic circuits. Both hydraulic circuits include a two-position two-way valve 509 and a two-position three-way valve 510, and both hydraulic circuits are connected to the hydraulic actuator 4. One of the circuits is connected to a second accumulator 513, which has a liquid chamber and a gas chamber, as well as an elastic diaphragm to separate the liquid chamber and the gas chamber. The two-position three-way valves 510 in the two hydraulic circuits are also connected to two damping circuits. Each damping circuit is connected to a variable damper 511 and a branch check valve 512.

[0030] The pneumatic system 6 includes an air pump 601 and a pneumatic valve block 603 connected to the air pump 601. The pneumatic valve block 603 has four starting branches, each of which is connected to a pneumatic check valve 602. The pneumatic check valve 602 is connected to an adjustable pressure relief valve 604, which is connected to a second accumulator 513 to provide air pressure to the air chamber of the second accumulator 513, thereby transmitting the pre-charge pressure through the elastic diaphragm.

[0031] The system also includes a control system 10, which is also mounted on the chassis 3. The control system 10 includes a central controller 1003, a road surface pre-aiming sensor 1001 and a vehicle body attitude sensor 1002, which are electrically connected to the central controller 1003. The road surface pre-aiming sensor 1001 is located at the front end of the bottom of the chassis 3 to collect the elevation information of the road surface ahead. The central controller 1003 is also electrically connected to the hydraulic oil circuit system 5 and the pneumatic system 6, and switches between the vehicle's passive mode, semi-active mode and active mode by controlling the hydraulic oil circuit system 5 and the pneumatic system 6.

[0032] The front upper suspension spring 401 and the front lower suspension spring 403, and the rear upper suspension spring 801 and the rear lower suspension spring 803 have different stiffnesses. Their stiffness is set according to the actual vehicle weight distribution and suspension damping requirements; for example, let the weight of the high-stiffness wheel 1 be... The weight that the wheels can bear is The acceleration due to gravity is The spring stiffnesses are respectively The spring compressions are respectively The maximum extension of hydraulic actuator 4 is recorded as follows: Then it needs to satisfy , , Considering the suspension damping requirements, the vertical acceleration of the high-rigidity wheel 1 during road travel is denoted as... Then it needs to satisfy After meeting the above requirements, select a suitable spring stiffness setting standard. In general, the upper suspension springs are selected with lower stiffness, while the lower suspension springs are selected with higher stiffness. The choice of spring stiffness is based on the need to cope with the filtering requirements of road excitation at more frequencies.

[0033] The front wheel suspension inertia container 402 and the rear wheel suspension inertia container 802 convert the vertical motion of the high-rigidity wheel 1 into inertial resistance force. The selection of the rotational inertia of the inertia container is based on suppressing the spring compression and rebound amplitude. When the suspension moves up and down, it drives the two ends of the inertia container, generating relative linear motion. This linear motion is converted into rotational motion through the ball screw pair. This, in turn, drives the flywheel to rotate at high speed, generating angular acceleration α, which requires the application of a torque. According to the rotational form of Newton's second law, this torque is proportional to the angular acceleration, i.e., M=Jα, where J is the rotational inertia. This required torque acts in the opposite direction on the suspension, manifesting as a force that opposes the vertical motion of wheel 1, thereby suppressing the spring compression and rebound amplitude and effectively isolating the vibration transmission between the wheel and the vehicle body.

[0034] This invention also provides a method for controlling a multimodal servo suspension system for high-rigidity wheeled vehicles, such as... Figure 8 As shown, it includes the following steps: S1: Initialize the suspension system and acquire data: The central controller 1003 controls the hydraulic pump 502 to continuously supply oil to the first accumulator 507 until the internal pressure of the first accumulator 507 reaches the set threshold. If the internal pressure does not reach the set threshold, the hydraulic pump 502 continues to supply oil to replenish the pressure.

[0035] The road surface pre-aiming sensor 1001 collects road surface elevation information and obtains the ground clearance of the chassis 3, while the vehicle body attitude sensor 1002 obtains vehicle body attitude information.

[0036] S2: The central controller 1003 receives the collected road surface elevation information, chassis ground clearance information and vehicle posture information, and obtains basic vehicle data information and vehicle driving status information.

[0037] S3: Calculate the ground clearance suitable for vehicle driving based on the information obtained in S2 and select the suspension mode. Control the pneumatic system 6 to change the air pressure inside the gas chamber of the second accumulator 513, and then adjust the ground clearance of the chassis 3 through the hydraulic actuator 4.

[0038] The suspension modes include: passive mode, semi-active mode and active mode; the central controller 1003 controls the hydraulic oil circuit system 5 and the pneumatic system 6 to put the vehicle into the corresponding suspension mode.

[0039] The suspension system switches between passive, semi-active, and active modes using hydraulic components such as servo valve 508, two-position two-way valve 509, two-position three-way valve 510, and variable damper 511. The specific switching methods are as follows: 1. Passive Mode: The central controller 1003 outputs a control signal to set the two-position two-way valve 509 to the shut-off position, the two-position three-way valve 510 to the A / T connection position, and the servo valve 508 to the middle position. At the same time, the input signal of the variable damper 511 is fixed, that is, the damping value provided by the variable damper 511 is a constant value. For the two variable dampers 511 on the same hydraulic branch, their damping values ​​are different to ensure that the damping value of the hydraulic actuator 4 corresponding to the hydraulic branch is different during compression or rebound motion.

[0040] The specific steps to enable passive mode include: Based on the vehicle's basic data, the ground clearance of the chassis 3, and the vehicle's driving status, the fixed damping values ​​of the compression circuit and rebound circuit of each hydraulic actuator 4 are determined respectively.

[0041] The central controller 1003 converts the damping values ​​of the compression circuit and rebound circuit of each hydraulic actuator 4 into control signals for the variable damper 511 and sets a fixed output.

[0042] Passive mode: The 2-position 2-way valve 509 is in the off position, the 2-position 3-way valve 510 is in the A / T connection position, and the servo valve 508 is in the neutral position. That is, the two oil circuits of the hydraulic actuator 4 form a loop through the 2-position 3-way valve 510, the variable damper 511, and the branch check valve 512. When the hydraulic actuator 4 actuates, due to the action of the branch check valve 512, the hydraulic actuator 4 extends through one of the variable dampers 511 and retracts through the other variable damper 511. When the damping values ​​provided by the two variable dampers 511 are different, the speeds of the hydraulic actuator 4's extension and retraction will differ, thus meeting the vibration reduction requirements of the actual vehicle in passive mode. Since the oil volume in the rod chamber is different from that in the rodless chamber, this oil difference is stored or replenished through the second accumulator.

[0043] In passive mode, the input signals of the two variable dampers 511 are fixed and have different values ​​to ensure that the damping value of the hydraulic actuator 4 corresponding to the hydraulic branch is different during compression or rebound. In passive mode, the suspension has the highest reliability, the least loss of each component of the entire suspension system, and the lowest energy consumption, but the corresponding vibration reduction effect is the worst.

[0044] II. Semi-active mode: The central controller 1003 outputs a control signal to set the two-position two-way valve 509 to the shut-off position, the two-position three-way valve 510 to the A / T connection position, and the servo valve 508 to the middle position. At the same time, the input signal of the variable damper 511 is calculated in real time by the algorithm of the central controller 1003. That is, the damping magnitude provided by the variable damper 511 is calculated in real time by the algorithm of the central controller 1003. In order to reduce the calculation load of the central controller 1003, in the semi-active mode, the input signals of the two variable dampers 511 on the same hydraulic branch can be the same.

[0045] The specific steps to enable semi-active mode include: The central controller 1003 combines the vehicle's driving status, forward road surface information, and vehicle attitude information, and also incorporates the seven-degree-of-freedom dynamics formula for the entire vehicle with variable suspension damping. It then substitutes the vehicle attitude information into the formula and performs an inverse solution to calculate the damping value corresponding to each hydraulic actuator 4. The vehicle has seven degrees of freedom, including the vertical axis of the vehicle body. , looking up Lateral tilt Movement and vertical movement of the four wheels (front left) , right front Left rear Right rear ).

[0046] For vehicle body weight; The moment of inertia of the vehicle body during pitch; The moment of inertia due to vehicle roll; , , , For the mass of the wheel; , , , This refers to the suspension spring stiffness; , , , The damping value for hydraulic actuator 4; , , , For tire stiffness; , , , For road surface excitation; For pitch lever arm; It is the tilt arm.

[0047] Vertical movement of the vehicle body: .

[0048] Vehicle pitch motion: .

[0049] Body roll motion: .

[0050] Left front wheel movement: .

[0051] Right front wheel movement: .

[0052] Left front wheel movement: .

[0053] Left front wheel movement: .

[0054] The central controller 1003 converts the damping value of each hydraulic actuator 4 into a control signal for the variable damper 511, thereby realizing continuous adjustment of the damping value of each hydraulic actuator 4.

[0055] Semi-active mode: The two-position two-way valve 509 is in the off position, the two-position three-way valve 510 is in the A / T connection position, and the servo valve is in the neutral position, consistent with the passive mode. In semi-active mode, the damping value provided by the variable damper 511 is not fixed, that is, its input signal is continuously variable, and the specific value is calculated in real time by the central controller in combination with vehicle status and other information.

[0056] In semi-active mode, the input signals of the two variable dampers 511 can be the same. In semi-active mode, the suspension system reliability is the weakest, the loss of the variable damper 511 is relatively high, the energy consumption is slightly higher than that in passive mode but much lower than that in active mode, and the vibration reduction effect is between the two.

[0057] III. Active Mode: The central controller 1003 outputs a control signal to set the two-position two-way valve 509 to the flow position, the two-position three-way valve 510 to the A / P connection position, and the variable damper 511 to close. The hydraulic pump 502 starts working and supplies pressure to the main hydraulic circuit. The input signals of each servo valve 508 are calculated in real time by the algorithm of the central controller 1003. The servo valves 508 control the actuation output of each hydraulic actuator 4, thereby realizing the active suppression of road vibration transmission by each hydraulic actuator 4.

[0058] The specific steps to activate the active mode include: the central controller 1003 combines the vehicle driving status, the pre-aimed road surface information and the vehicle body attitude information, and at the same time, it uses the vehicle body attitude information and the kinematic relationship of the whole vehicle suspension to back-calculate the extension and retraction of each hydraulic actuator 4.

[0059] The extension and retraction of each hydraulic actuator 4 is used as a reference signal for the servo valve 508 to control the hydraulic actuator 4, and the actual extension and retraction displacement of the hydraulic actuator 4 is used as the output signal. The central controller 1003 calculates and outputs the control signal of the servo valve 508 by improving the error tracking model-free adaptive control algorithm, thereby realizing the closed-loop control of each hydraulic actuator 4.

[0060] The advantages of the improved error tracking model-free adaptive control algorithm are that, as a model-free control method, it does not require the establishment of a mathematical model of the controlled system, has a smaller computational load and better control effect; the introduction of an error tracking term gives it better anti-interference performance.

[0061] The central controller 1003 judges vehicle stability by monitoring changes in vehicle body posture data, dynamic data, steering wheel control data, vehicle braking data, and pre-aiming road elevation information in real time. When a sudden change occurs in vehicle stability, such as sudden braking, sudden turning, or body roll at high speed, the active mode quickly intervenes, and the hydraulic pump 502 is no longer limited by the internal pressure of the first accumulator 507, and continues to work to supply oil to the suspension system.

[0062] The determination of vehicle driving status mainly includes changes in observable data during vehicle driving, such as vehicle speed V, anticipated road surface grade, and increases or decreases in vehicle speed.

[0063] When the active mode is enabled, the improved error tracking model-free adaptive control algorithm is as follows: Indicates the first The timing servo valve 508 control signal, Indicates the first The actual extension and retraction displacement of the hydraulic actuator 4 at all times. Indicates the first Reference signal at time, Indicates the first The timing servo valve 508 control signal, Indicates the first The actual extension and retraction displacement of the hydraulic actuator 4 at all times. Indicates the first Reference signal at time; ; in, These are the weighting coefficients. Step size factor As a weighting factor, As a weighting factor, It is the first step in the actual control process Time-varying parameters at time t, It is the first Time-varying parameters at time t, yes The estimated value, for The estimated value, The time-varying weighting coefficients and the algorithm for estimating the time-varying parameters are as follows: ; in, This represents the actual change in extension and retraction displacement of the hydraulic actuator 4 at adjacent moments. ; To enhance the estimation algorithm's ability to track time-varying parameters, reset conditions are designed: ,when or or ; in, Indicates the step size coefficient. It is a very small positive number. yes The initial value.

[0064] Active mode: The 2-position 2-way valve 509 is in the flow position, the 2-position 3-way valve 510 is in the A / P connection position, and the variable damper 511 is closed. At this time, no hydraulic oil flows through the variable damper 511 or the branch check valve 512. The hydraulic pump 502 and the first accumulator 507 supply pressure to the main hydraulic circuit. The input signals of each servo valve are calculated in real time by the central controller algorithm. In active mode, it is equivalent to a servo valve controlling an asymmetric hydraulic actuation system. At this time, the reliability of the suspension system is between passive and semi-active, with the highest energy consumption and the best vibration reduction effect.

[0065] The stiffness of the front upper suspension spring 401 is less than that of the front lower suspension spring 403, and the stiffness of the rear upper suspension spring 801 is less than that of the rear lower suspension spring 803. The values ​​are set according to the actual vehicle weight distribution and suspension compression stroke. The selection of the two spring stiffnesses is based on the need to cope with the filtering requirements of road excitation at more frequencies. The inertia containers of the front and rear suspensions convert the vertical motion of the high-stiffness wheels into inertial resistance. The selection of the rotational inertia of the inertia containers is based on suppressing the spring compression and rebound amplitude.

[0066] Lower stiffness suspension springs can effectively isolate road surfaces with high frequency and small undulations; higher stiffness suspension springs are mainly designed for road surfaces with low frequency and large undulations.

[0067] The inertia containers in the front and rear suspensions convert the vertical motion of the high-rigidity wheels into inertial resistance. When road undulations cause the wheels to have a large vertical acceleration, the inertia containers provide inertial resistance, which on the one hand suppresses the transmission of wheel vibration to the vehicle body, and on the other hand couples the two springs to make the transmission of spring force between the two springs smoother.

[0068] The advantages of the improved error tracking model-free adaptive control algorithm are that, as a model-free control method, it does not require the establishment of a mathematical model of the controlled system, has a smaller computational load and better control effect; the introduction of an error tracking term gives it better anti-interference performance.

[0069] In passive or semi-active suspension mode, the ground clearance of chassis 3 can be adjusted by pneumatic system 6. By pressurizing each pneumatic branch through air pump 601 and cooperating with adjustable pressure relief valve 604, the internal pressure of second accumulator 513 is regulated, thereby changing the internal pressure of hydraulic actuator 4, which changes the extension length of hydraulic rod in hydraulic actuator 4. This, in conjunction with the compression or rebound of suspension springs, raises or lowers the ground clearance of chassis 3. For changes in ground clearance in passive mode, the input signal of variable damper 511 needs to be adjusted simultaneously. When the internal pressure of second accumulator 513 increases and the ground clearance of chassis 3 increases, the input signal of variable damper 511 in compression circuit is reduced to reduce compression damping, while the input signal of variable damper 511 in rebound circuit is increased to increase rebound damping. When the internal air pressure of the second accumulator 513 increases, the stiffness of the air chamber inside the second accumulator 513 increases, which causes the hydraulic actuator 4 to need to overcome greater resistance during the compression process. Therefore, the damping magnitude of the variable damper 511 in the compression circuit is reduced so that the damping values ​​of the suspension system before and after height adjustment are close.

[0070] S4: During vehicle operation, the central controller 1003 monitors whether the vehicle's driving status changes abruptly. If a change occurs, the central controller 1003 controls the vehicle to enter active mode.

[0071] Specifically, whether the vehicle's driving state changes abruptly is mainly determined by the central controller 1003 through real-time monitoring of changes in vehicle body posture data, steering wheel control data, vehicle braking data, and pre-aimed road surface elevation information, thereby predicting whether the vehicle's stability changes abruptly. When the vehicle's stability changes abruptly, the active mode quickly intervenes, and the hydraulic pump 502 is no longer limited by the internal pressure of the first accumulator 507, and continues to work to supply oil to the suspension system.

[0072] S5: After entering active mode, if the vehicle's driving status does not change suddenly within the set time, then continue executing S2.

[0073] S6: After completing the driving, the suspension system enters the termination procedure.

[0074] The following example, using a preferred embodiment, illustrates the principle of the suspension system control method of the present invention: like Figure 9 As shown, a specific embodiment of a multimodal servo suspension control method for high-stiffness wheeled vehicles is presented, which includes the following steps: S1: Initialize the vehicle suspension system and monitor the ground clearance of the chassis 3; the central controller 1003 acquires basic vehicle data, real-time vehicle driving status, and pre-aimed road surface information to classify it from A to E, with the smoothness gradually decreasing from A to E.

[0075] The pre-aiming road surface device acquires road surface elevation information X, and calculates the road surface unevenness ΔX based on the elevation information X. Let the maximum extension of the hydraulic actuator 4 be L. Then, the road surface grade is classified as follows: When The road surface is classified as Grade E, which represents the worst road surface suitable for vehicle travel, with a speed limit of 20 km / h. The road surface is classified as Class D, with a speed limit of 40 km / h; when The road surface is classified as Class C, with a speed limit of 60 km / h; when The road surface is classified as Class B, with a speed limit of 80 km / h; when 0 ≤ ΔX ≤ 0.2L, the road surface is classified as Class A, with a speed limit of 120 km / h; the initialization of the suspension system includes actions such as starting the hydraulic pump 502 and the air pump 601, and the suspension system is in passive mode during the initialization process.

[0076] S2: The central controller 1003 receives the collected road surface elevation information, chassis ground clearance information and vehicle posture information, and obtains basic vehicle data information and vehicle driving status information.

[0077] S3: Calculate the appropriate ground clearance for vehicle operation based on the information obtained in S2 and select the suspension mode. Control the pneumatic system to change the internal air pressure of the second accumulator gas chamber, and then adjust the ground clearance of the chassis through the hydraulic actuator 4.

[0078] The suspension modes include passive mode, semi-active mode, and active mode; the central controller controls the hydraulic and pneumatic systems to put the vehicle into the corresponding suspension mode.

[0079] S31: The central controller 1003 obtains the ground clearance of the chassis 3. When the ground clearance is not within the set range, the internal pressure of the small second accumulator 513 is adjusted through the pneumatic system 6, thereby adjusting the ground clearance of the chassis 3. The suspension mode is selected according to the driving speed V and the anticipated road surface level, including active mode, semi-active mode and passive mode.

[0080] S32: When 0≤V≤20Km / h and road surface grade E, activate active mode.

[0081] The road surface pre-aiming device acquires the road surface elevation information X ahead of the vehicle. The central controller 1003 combines the driving speed V and the elevation information X to calculate the extension and retraction amount Δpi of each hydraulic actuator 4, where i is the number of the hydraulic actuator 4, i=1, 2, 3, 4, corresponding to the left front, right front, right rear, and left rear wheels respectively. Therefore, ,in It is a piecewise function, which divides the vehicle speed into segments according to the magnitude of the value. Each segment corresponds to a coefficient, the value of which is determined experimentally.

[0082] The central controller 1003 acquires the vehicle's position and posture data during the current driving process, and controls the extension and retraction of each hydraulic actuator 4 by Δdi based on the feedback of the vehicle's position and posture data. The position and posture data includes the vertical displacement of the vehicle body, pitch angle, roll angle, and the extension and retraction of each hydraulic actuator 4 at the current moment. The acquired data is substituted into the vehicle position and posture calculation formula to back-calculate the extension and retraction of each hydraulic actuator 4 by Δdi when the vehicle's position and posture reach a stable state at the next moment.

[0083] If the extension and retraction data Δpi and Δdi of each hydraulic actuator 4 are aligned in the next control cycle, then the extension and retraction of each hydraulic actuator 4 in the next control cycle is Δpi + Δdi.

[0084] Each extension and retraction amount is used as a reference signal for the servo valve 508 to control the hydraulic actuator 4, and the actual extension and retraction displacement of the hydraulic actuator 4 is used as the output signal. The central controller 1003 calculates and outputs the control signal of the servo valve 508 through an improved error tracking model-free adaptive control algorithm, thereby realizing the closed-loop control of each hydraulic actuator 4.

[0085] S33: When 0≤V≤80Km / h and road surface grade A, B, C, or D, activate semi-active mode.

[0086] S331: When 0≤V≤40Km / h and road surface levels A, B, C, and D, a semi-active suspension control algorithm based on road elevation information fusion with vehicle dynamics control is adopted. The road surface pre-aiming device acquires the road surface elevation information X ahead of the vehicle, and then determines the elevation based on the change in elevation information X. Given the driving speed V, calculate the damping value qi of each hydraulic actuator 4, where i is the number of the hydraulic actuator 4, i=1, 2, 3, 4, corresponding to the left front, right front, right rear, and left rear wheels respectively; the value of qi is calculated using a fuzzy control algorithm. , The fuzzy control rules are formulated based on the actual vehicle model and actual test data.

[0087] The central controller 1003 acquires the real-time dynamics data of the vehicle at the current moment, and controls the damping value ci of each hydraulic actuator 4 based on the feedback of the vehicle dynamics data. The real-time dynamics data of the vehicle includes the vertical acceleration of the vehicle body, pitch acceleration, roll acceleration, extension and contraction of each hydraulic actuator 4 at the current moment and its rate of change. The acquired data is substituted into the vehicle dynamics calculation formula to back-calculate the damping value ci of each hydraulic actuator 4 at the next moment.

[0088] If the damping values ​​qi and ci of each hydraulic actuator 4 are aligned in the next control cycle, then the damping value of each hydraulic actuator 4 in the next control cycle is (qi+ci) / 2.

[0089] The central controller 1003 converts the damping value of each hydraulic actuator 4 into a control signal for the variable damper 511, thereby realizing continuous adjustment of the damping value of each hydraulic actuator 4.

[0090] S332: When 40≤V≤80km / h and road surface is classified as A, B, or C, considering the relatively high vehicle speed, the actual density of road elevation information obtained by the road surface pre-aiming device is low, making it difficult to meet the vehicle control requirements. However, the road surface smoothness is relatively good for A and B grade roads, and the maximum speed on C grade roads does not exceed 60km / h. Therefore, a semi-active suspension control algorithm based on vehicle dynamics control is adopted. The central controller 1003 acquires the real-time dynamics data of the vehicle at the current moment, and controls the damping value ci of each hydraulic actuator 4 based on the feedback of the vehicle dynamics data; in the next control cycle, the damping value of each hydraulic actuator 4 is ci.

[0091] Determine the vehicle's driving status. If the driving status changes, proceed to step S31; otherwise, re-execute step S322.

[0092] S34: When V≥80Km / h and road surface grade A, activate passive mode.

[0093] Based on the vehicle's basic data and the ground clearance of the chassis 3, the input signals of the variable dampers 511 in each hydraulic branch are set.

[0094] Vehicle dynamics data is recorded to assist the optimization algorithm in optimizing the set values ​​of compression damping and rebound damping in subsequent processes. The acquired data is then substituted into the vehicle dynamics calculation formula to back-calculate the damping value ci of each hydraulic actuator 4. Here, the damping value ci includes compression damping and rebound damping. The vehicle's stable state is recorded. Within a certain period of time, the damping value ci of each hydraulic actuator 4 is generally set according to the recording capability of the central controller 1003. Taking the recorded data of a certain hydraulic actuator 4 as an example, abnormal data of compression damping and rebound damping are removed respectively, and the remaining data are averaged to finally obtain the optimized compression damping and rebound damping.

[0095] S4: The central controller 1003 detects whether the vehicle's driving state changes abruptly. If a change occurs, it runs the suspension active mode intervention program and jumps to S32; otherwise, it continues to the next step.

[0096] S5: After entering active mode, if the vehicle's driving status does not change suddenly within the set time, then continue executing S2.

[0097] S6: Has the vehicle completed the driving process? If the driving process continues, proceed to S31. If the driving process is completed, the suspension system enters the termination program setting, maintains the suspension system working state until the vehicle stops, the suspension system enters the stop program setting, the suspension system enters the passive mode, the adjustable pressure relief valve 604 regulates the pressure of the second accumulator 513 to the initial pressure, and the hydraulic pump 502 and air pump 601 stop working.

[0098] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multimodal servo suspension system for a high-rigidity wheeled vehicle, comprising a chassis (3), a suspension structure connected to the chassis (3), and a plurality of wheels (1) connected to the suspension structure, characterized in that, The suspension structure includes: Hydraulic actuator (4): Its top is fixed to the chassis (3), and its bottom is rotatably mounted on the connecting structure for connecting the chassis (3) and the wheel (1); Inertia container assembly: It includes an upper spring, an inertia container and a lower spring sleeved on the outside of the hydraulic actuator (4), the inertia container being located between the upper spring and the lower spring and being able to float up and down; Hydraulic circuit system (5): It is mounted on the chassis (3) and includes an oil tank (501), a hydraulic pump (502) connected to the oil tank, a hydraulic valve block (506) connected to the hydraulic pump (502), and a first accumulator (507) connected to the hydraulic valve block (506). The hydraulic valve block (506) is also connected to a servo valve (508). The servo valve (508) connects two hydraulic circuits, and both hydraulic circuits include a two-position two-way valve (509) and a... Two-position three-way valves (510) are provided, and both hydraulic circuits are connected to the hydraulic actuator (4). One of the circuits is connected to a second accumulator (513). The second accumulator (513) is provided with a liquid chamber and a gas chamber, as well as an elastic diaphragm for separating the liquid chamber and the gas chamber. Two damping circuits are also connected between the two-position three-way valves (510) in the two hydraulic circuits. Each damping circuit is connected to a variable damper (511) and a branch check valve (512). Pneumatic system (6): It is mounted on the chassis (3) and connected to the second accumulator (513) to provide air pressure to the gas chamber of the second accumulator (513); Control system (10): It is set on the chassis (3) and includes a central controller (1003), a road surface pre-aiming sensor (1001) and a vehicle body attitude sensor (1002) which are electrically connected to the central controller (1003). The road surface pre-aiming sensor (1001) is set at the front end of the bottom of the chassis (3) to collect the elevation information of the road surface ahead. The central controller (1003) is also electrically connected to the hydraulic oil circuit system (5) and the pneumatic system (6) and realizes the switching of the vehicle passive mode, semi-active mode and active mode by controlling the hydraulic oil circuit system (5) and the pneumatic system (6).

2. The multimodal servo suspension system for high-rigidity wheeled vehicles as described in claim 1, characterized in that: The pneumatic system (6) includes an air pump (601) and a pneumatic valve block (603) connected to the air pump (601). The pneumatic valve block (603) is connected to several pneumatic branches. Each pneumatic branch is equipped with an adjustable pressure relief valve (604). The first end of the adjustable pressure relief valve (604) is connected to the pneumatic valve block (603) through a pneumatic check valve (602), and the second end is connected to the gas chamber of the second accumulator (513).

3. The multimodal servo suspension system for high-rigidity wheeled vehicles as described in claim 1, characterized in that: The hydraulic circuit system (5) also includes a relief valve (503), a hydraulic filter (504) and a main line check valve (505). The hydraulic pump (502) is connected to the hydraulic valve block (506) through the hydraulic filter (504) and the main line check valve (505). The first end of the relief valve (503) is connected to the pipeline between the hydraulic pump (502) and the hydraulic filter (504), and the second end is connected to the oil tank (501).

4. The multimodal servo suspension system for high-rigidity wheeled vehicles as described in claim 1, characterized in that: The suspension structure includes a front swing arm (2) for connecting the front wheel (1) to the chassis (3) and a rear axle (7) for connecting the rear wheel (1) to the chassis (3); wherein, the front swing arm (2) is provided in two sets, which are fixedly installed on both sides of the chassis (3), and each set of front swing arms (2) is provided with a hydraulic actuator (4), and the rear axle (7) is provided with two hydraulic actuators (4).

5. The multimodal servo suspension system for high-rigidity wheeled vehicles as described in claim 4, characterized in that: Replace the hydraulic actuator (4) inside the inertial container assembly on the rear axle (7) with a telescopic rod (8). The top of the telescopic rod (8) is fixedly connected to the chassis (3), and the bottom is fixedly installed on the rear axle (7). The top of the hydraulic actuator (4) on the rear axle (7) is fixedly connected to the chassis (3), and the bottom is rotatably installed on the rear axle (7).

6. A method for controlling a multimodal servo suspension system for a high-rigidity wheeled vehicle as described in any one of claims 1 to 5, characterized in that: It includes the following steps: S1: Initialize the suspension system and data acquisition: The central controller (1003) controls the hydraulic pump (502) to continuously supply oil to the first accumulator (507) until the internal pressure of the first accumulator (507) reaches the set threshold. Once the internal pressure does not reach the set threshold, the hydraulic pump (502) continues to supply oil to replenish the pressure. The road surface pre-aiming sensor (1001) collects road surface elevation information and obtains the ground clearance of the chassis (3), while the vehicle body attitude sensor (1002) obtains vehicle body attitude information; S2: The central controller (1003) receives the collected road elevation information, chassis (3) ground clearance information and vehicle posture information, and obtains vehicle basic data information and vehicle driving status information. S3: Calculate the ground clearance suitable for vehicle driving based on the information obtained in S2 and select the suspension mode. Control the pneumatic system (6) to change the air pressure inside the gas chamber of the second accumulator (513), and then adjust the ground clearance of the chassis (3) through the hydraulic actuator (4). The suspension modes include: passive mode, semi-active mode and active mode; the central controller (1003) controls the hydraulic oil circuit system (5) and the pneumatic system (6) to put the vehicle into the corresponding suspension mode; S4: During vehicle operation, the central controller (1003) monitors whether the vehicle's driving status changes abruptly. If a change occurs, the central controller (1003) controls the vehicle to enter active mode. S5: After entering active mode, if the vehicle's driving status does not change suddenly within the set time, then continue to execute S2; S6: After completing the driving, the suspension system enters the termination procedure.

7. The control method for the multimodal servo suspension system of a high-rigidity wheeled vehicle as described in claim 6, characterized in that: The steps to enable passive mode include: Based on the vehicle's basic data, the ground clearance of the chassis (3), and the vehicle's driving status, the fixed damping values ​​of the compression and rebound circuits of each hydraulic actuator (4) are determined. The central controller (1003) converts the damping values ​​of the compression circuit and rebound circuit of each hydraulic actuator (4) into control signals of the variable damper (511) and fixes the output.

8. The control method for the multimodal servo suspension system of a high-rigidity wheeled vehicle as described in claim 6, characterized in that: The steps to enable semi-active mode include: The central controller (1003) combines vehicle driving status information, road elevation information and vehicle dynamics data, and combines the vehicle's seven-degree-of-freedom dynamics formula with variable damping suspension. It then substitutes the vehicle dynamics data into the formula and solves it inversely to calculate the damping value corresponding to each hydraulic actuator (4). The central controller (1003) converts the damping value of each hydraulic actuator (4) into the control signal of the variable damper (511) to realize the continuous adjustment of the damping value of each hydraulic actuator (4).

9. The control method for the multimodal servo suspension system of a high-rigidity wheeled vehicle as described in claim 6, characterized in that: The steps to enable active mode include: The central controller (1003) combines vehicle driving status information, road elevation information and vehicle body posture information, and calculates the extension and retraction of each hydraulic actuator (4) based on the relationship between vehicle body posture information and vehicle suspension kinematics. The extension and retraction of each hydraulic actuator (4) is used as the reference signal for the servo valve (508) to control each hydraulic actuator (4), and the actual extension and retraction displacement of each hydraulic actuator (4) is used as the output signal. The central controller (1003) calculates and outputs the control signal of the servo valve (508) through an improved error tracking model-free adaptive control algorithm, thereby realizing the closed-loop control of each hydraulic actuator (4). Indicates the first The timing servo valve (508) control signal, Indicates the first The actual extension and retraction displacement of the hydraulic actuator (4) at any given time. Indicates the first Reference signal at time, Indicates the first The timing servo valve (508) control signal, Indicates the first The actual extension and retraction displacement of the hydraulic actuator (4) at any given time. Indicates the first Reference signal at time; ； in, These are the weighting coefficients. Step size factor As a weighting factor, As a weighting factor, It is the first step in the actual control process Time-varying parameters at time t, It is the first Time-varying parameters at time t, yes The estimated value, for The estimated value, The time-varying weighting coefficients and the algorithm for estimating the time-varying parameters are as follows: ； in, The actual extension and retraction displacement of the hydraulic actuator (4) at adjacent moments is the change in displacement. ; To enhance the estimation algorithm's ability to track time-varying parameters, reset conditions are designed: ,when or or ; in, Indicates the step size coefficient. It is a very small positive number. yes The initial value.

10. The control method for the multimodal servo suspension system of a high-rigidity wheeled vehicle as described in claim 6, characterized in that: After the active mode is activated, the hydraulic pump (502) is no longer limited by the set threshold of the internal pressure of the first accumulator (507) and continues to work to supply oil to the suspension system.

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