阅读说明：本技术 多轴车辆车姿调节系统 (Multi-axle vehicle posture adjusting system ) 是由 陈轶杰 郑冠慧 张亚峰 高晓东 黄龙 雷强顺 万义强 徐梦岩 赵宁 王乐 代健健 于 2021-01-29 设计创作，主要内容包括：本发明公开了一种多轴车辆车姿调节系统,属于液压机械和机动车应用技术领域。系统中的油气弹簧分为左前、右前、左后、右后四组,每组油气弹簧对应一套蓄能器减振阀组,每组油气弹簧的无杆腔相互连通,有杆腔也相互连通,形成四组平衡悬挂；左前油气弹簧组合的无杆腔与右前油气弹簧组合的有杆腔连通,左前油气弹簧组合的有杆腔与右前油气弹簧组合的无杆腔连通,左后油气弹簧组合的无杆腔与右后油气弹簧组合的有杆腔连通,左后油气弹簧组合的有杆腔与右后油气弹簧组合的无杆腔连通,形成整车抗侧倾互联式平衡悬挂。本发明能够显著提升车辆转弯时的抗侧倾能力,改善执行机构工作环境,提高车姿调节平稳度和精度,有效降低动力单元的功率损耗。(The invention discloses a multi-axis vehicle posture adjusting system, and belongs to the technical field of hydraulic machinery and motor vehicle application. The hydro-pneumatic springs in the system are divided into four groups, namely a left front group, a right front group, a left back group and a right back group, each group of hydro-pneumatic springs corresponds to one energy accumulator damping valve group, rodless cavities of each group of hydro-pneumatic springs are mutually communicated, rod cavities of each group of hydro-pneumatic springs are also mutually communicated, and four groups of balanced suspensions are formed; the rodless cavity of the left front hydro-pneumatic spring combination is communicated with the rodless cavity of the right front hydro-pneumatic spring combination, the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination, and the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination to form the anti-side-tipping interconnected balance suspension of the whole vehicle. The invention can obviously improve the anti-roll capability of the vehicle during turning, improve the working environment of the actuating mechanism, improve the stability and precision of vehicle attitude adjustment and effectively reduce the power loss of the power unit.)

1. The multi-axle vehicle attitude adjusting system comprises a main pressure control valve group, an energy accumulator damping valve group, a load pressure self-feedback attitude adjusting valve group, a system pressure control valve group, an oil-gas spring and a controller; the hydro-pneumatic spring system is characterized in that the hydro-pneumatic springs are divided into four groups, namely a left front group, a right front group, a left rear group and a right rear group, each hydro-pneumatic spring corresponds to one energy accumulator damping valve group, the number of the hydro-pneumatic spring combinations of the left front group, the right front group, the left rear group and the right rear group is the same, rodless cavities of the hydro-pneumatic springs in each group are mutually communicated, rod cavities are mutually communicated, and therefore four groups of balanced suspensions are formed; the rodless cavity of the left front hydro-pneumatic spring combination is communicated with the rodless cavity of the right front hydro-pneumatic spring combination, the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination, and the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination; in addition, the rodless cavities combined by the left front oil-gas spring, the right front oil-gas spring, the left rear oil-gas spring and the right rear oil-gas spring are communicated with the energy accumulator damping valve group to realize a damping and buffering function, so that the anti-side-tipping interconnected balance suspension of the whole vehicle is formed; displacement sensors are respectively arranged on hydro-pneumatic springs at the four farthest end points of the left front part, the right front part, the left rear part and the right rear part of the whole vehicle;

the controller extracts the stroke and internal pressure change values of the hydro-pneumatic spring at each position, respectively calculates the arithmetic mean value and root mean square value of the stroke and pressure change of the hydro-pneumatic spring within a specified time, compares the arithmetic mean value and the root mean square value with the height of the vehicle body at the initial static balance position to obtain the vehicle posture height change quantity in the vehicle driving process, charges or discharges the hydro-pneumatic spring in the corresponding position balance suspension through a main pressure control valve group, a load pressure self-feedback vehicle posture adjusting valve group and a system pressure control valve group according to the set program, and compares the data with a target value in real time by acquiring corresponding displacement sensor data until the required vehicle posture height is reached;

the controller simultaneously extracts the pressure and the stroke change value of each wheel of hydro-pneumatic spring, judges the load state and the road surface condition of a single wheel, and adjusts the damping of the energy accumulator vibration reduction valve group through the load pressure self-feedback vehicle posture adjusting valve group after comparing with the initial damping setting.

2. The multi-axle vehicle attitude adjusting system according to claim 1, wherein the main pressure control valve set is used for detecting and controlling the working pressure of the vehicle attitude adjusting system, receiving the maximum pressure feedback signal of the vehicle attitude adjusting system, and realizing that the pressure of the vehicle attitude adjusting system is only 0.6 Mpa-0.9 Mpa higher than the maximum load pressure all the time.

3. The multi-axle vehicle attitude adjusting system according to claim 2, wherein an energy accumulator is mounted on an Ac oil outlet of the energy accumulator damping valve bank, oil suction ports of the power source and the pump are connected with an oil outlet of an oil tank, a P1 oil inlet of the main pressure control valve bank is connected with an oil outlet of the power source and the pump, and pressure oil at an outlet of the pump enters the system after being regulated by the main pressure control valve bank; the oil outlet P of the main pressure control valve group is simultaneously connected with the pressure control port Pa of each energy accumulator vibration reduction valve group through a pipeline to provide hydraulic control force for damping adjustment; the oil outlet of the main pressure control valve group is also connected with a P oil inlet of the load pressure self-feedback vehicle attitude adjusting valve group through a pipeline to charge oil for the oil-gas spring; the oil outlet A of the load pressure self-feedback vehicle posture adjusting valve group is connected with the balance suspension on the left side, the oil outlet B is connected with the balance suspension on the right side, and the oil return port T is connected with the oil return port of the oil tank.

4. The multi-axle vehicle attitude adjustment system according to claim 3, wherein the load pressure self-feedback attitude adjustment valve group is divided into a front load pressure self-feedback attitude adjustment valve group and a rear load pressure self-feedback attitude adjustment valve group according to the arrangement position, the Ka load pressure feedback port of the front load pressure self-feedback vehicle posture adjusting valve group is connected with the left front balance suspension, the Kb load pressure feedback port is connected with the right front balance suspension, for comparing the left and right front counterbalancing suspension load pressures and forming a pressure feedback loop, a Ka load pressure feedback port of the rear load pressure self-feedback vehicle posture adjusting valve group is connected with the left rear balance suspension, a Kb load pressure feedback port is connected with the right rear balance suspension, the pressure feedback loop is used for comparing the load pressure of the left rear balance suspension and the right rear balance suspension and forming a pressure feedback loop for controlling the lifting stability of the balance suspensions on the two sides.

5. The multi-axle vehicle attitude adjusting system according to claim 4, wherein the pressure control valve group is connected to the left front suspension at the Fa end, collects the left front load pressure of the vehicle, is connected to the right front suspension at the Fb end, collects the right front load pressure of the vehicle, is connected to the left rear suspension at the Ra end, collects the left rear load pressure of the vehicle, is connected to the right rear suspension at the Rb end, collects the right rear load pressure of the vehicle, and compares the load pressures in the pressure control valve group, the PLs port outputs the maximum load pressure of the whole vehicle, the PLs port is connected with a pressure feedback LS port of the main pressure valve group, this maximum load pressure is input through the LS port as a control pressure for controlling the maximum actual working pressure of the entire system, the actual working pressure of the whole system is always higher than the maximum load pressure by 0.6-0.9 Mpa.

6. The multi-axle vehicle attitude adjustment system of claim 5, wherein an As outlet port and an Ac outlet port between said accumulator damper valve bank communicate through a damping control valve.

Technical Field

The invention relates to a multi-axis vehicle posture adjusting system, and belongs to the technical field of hydraulic machinery and motor vehicle application.

Background

Along with the continuous improvement of the requirements on the vehicle transport capacity, the running stability, the safety and the comfort in the production operation process, particularly the warehousing and transportation equipment with large load change, a set of vehicle posture adjusting system is required to be added while the hydro-pneumatic spring is matched, the consistency of the vehicle bottom and ground clearance in an empty and full load state and the trafficability of an uneven road surface are ensured by controlling the vehicle body posture, and the dangerous phenomena of side turning and the like of the vehicle under a special operation condition can be effectively avoided so as to meet the requirements of the vehicle on the adaptability of the entire road surface.

Disclosure of Invention

In view of this, the invention provides a multi-axle vehicle posture adjusting system, which can significantly improve the anti-roll capability of a vehicle during turning, improve the working environment of an actuating mechanism, improve the stability and precision of vehicle posture adjustment, and effectively reduce the power loss of a power unit.

A multi-shaft vehicle attitude adjusting system comprises a main pressure control valve group, an energy accumulator damping valve group, a load pressure self-feedback attitude adjusting valve group, a system pressure control valve group, an oil-gas spring and a controller; the hydro-pneumatic springs are divided into four groups, namely a left front group, a right front group, a left back group and a right back group, each group of hydro-pneumatic springs corresponds to one energy accumulator damping valve group, the number of the hydro-pneumatic spring groups in the left front group, the right front group, the left back group and the right back group is the same, rodless cavities and rod cavities of the hydro-pneumatic springs in each group are mutually communicated, and therefore four groups of balanced suspensions are formed; the rodless cavity of the left front hydro-pneumatic spring combination is communicated with the rodless cavity of the right front hydro-pneumatic spring combination, the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination, and the rodless cavity of the left rear hydro-pneumatic spring combination is communicated with the rodless cavity of the right rear hydro-pneumatic spring combination; in addition, the rodless cavities combined by the left front oil-gas spring, the right front oil-gas spring, the left rear oil-gas spring and the right rear oil-gas spring are communicated with the energy accumulator damping valve group to realize a damping and buffering function, so that the anti-side-tipping interconnected balance suspension of the whole vehicle is formed; displacement sensors are respectively arranged on hydro-pneumatic springs at the four farthest end points of the left front part, the right front part, the left rear part and the right rear part of the whole vehicle;

the controller extracts the stroke and internal pressure change values of the hydro-pneumatic spring at each position, respectively calculates the arithmetic mean value and root mean square value of the stroke and pressure change of the hydro-pneumatic spring within a specified time, compares the arithmetic mean value and the root mean square value with the height of the vehicle body at the initial static balance position to obtain the vehicle posture height change quantity in the vehicle driving process, charges or discharges the hydro-pneumatic spring in the corresponding position balance suspension through a main pressure control valve group, a load pressure self-feedback vehicle posture adjusting valve group and a system pressure control valve group according to the set program, and compares the data with a target value in real time by acquiring corresponding displacement sensor data until the required vehicle posture height is reached;

the controller simultaneously extracts the pressure and the stroke change value of each wheel of hydro-pneumatic spring, judges the load state and the road surface condition of a single wheel, and adjusts the damping of the energy accumulator vibration reduction valve group through the load pressure self-feedback vehicle posture adjusting valve group after comparing with the initial damping setting.

Furthermore, the main pressure control valve group is used for detecting and controlling the working pressure of the vehicle posture adjusting system, receiving the maximum pressure feedback signal of the vehicle posture adjusting system and realizing that the pressure of the vehicle posture adjusting system is only 0.6-0.9 MPa higher than the maximum load pressure all the time.

Furthermore, an energy accumulator is arranged on an Ac oil outlet of the energy accumulator vibration reduction valve bank, oil suction ports of a power source and a pump are connected with an oil outlet of an oil tank, a P1 oil inlet of a main pressure control valve bank is connected with the oil outlet of the power source and the pump, and pressure oil at an outlet of the pump enters a system after being regulated by the main pressure control valve bank; the oil outlet P of the main pressure control valve group is simultaneously connected with the pressure control port Pa of each energy accumulator vibration reduction valve group through a pipeline to provide hydraulic control force for damping adjustment; the oil outlet of the main pressure control valve group is also connected with a P oil inlet of the load pressure self-feedback vehicle attitude adjusting valve group through a pipeline to charge oil for the oil-gas spring; the oil outlet A of the load pressure self-feedback vehicle posture adjusting valve group is connected with the balance suspension on the left side, the oil outlet B is connected with the balance suspension on the right side, and the oil return port T is connected with the oil return port of the oil tank.

The load pressure self-feedback car posture adjusting valve group is divided into a front load pressure self-feedback car posture adjusting valve group and a rear load pressure self-feedback car posture adjusting valve group according to the arrangement position, a Ka load pressure feedback port of the front load pressure self-feedback car posture adjusting valve group is connected with the left front balance suspension, a Kb load pressure feedback port is connected with the right front balance suspension and used for comparing the load pressures of the left front balance suspension and the right front balance suspension and forming a pressure feedback loop, a Ka load pressure feedback port of the rear load pressure self-feedback car posture adjusting valve group is connected with the left rear balance suspension, a Kb load pressure feedback port is connected with the right rear balance suspension and used for comparing the load pressures of the left rear balance suspension and the right rear balance suspension and forming a pressure feedback loop and used for controlling the lifting stability of the balance suspensions at two sides.

Further, the Fa end of the system pressure control valve group is connected with the left front balance suspension to collect the load pressure of the left front part of the vehicle, the Fb end is connected with the right front balance suspension to collect the load pressure of the right front part of the vehicle, the Ra end is connected with the left rear balance suspension to collect the load pressure of the left rear part of the vehicle, the Rb end is connected with the right rear balance suspension to collect the load pressure of the right rear part of the vehicle, after the load pressures of all parts are compared through the internal pressure of the system pressure control valve group, the maximum load pressure of the whole vehicle is output through the PLs port, the PLs port is connected with the pressure feedback LS port of the main pressure valve group, the maximum load pressure is input through the LS port to be the control pressure for controlling the maximum actual working pressure of the whole system, and the actual working pressure of the whole system is always higher than the maximum load.

Further, an As oil outlet and an Ac oil outlet between the energy accumulator vibration reduction valve groups are communicated through a damping control valve.

Has the advantages that:

compared with the traditional adjusting system, the multi-axle vehicle posture adjusting system creatively provides an interconnected balance suspension structure, can obviously improve the anti-roll capability of the vehicle during turning on the premise of not adding a transverse stabilizer bar, can effectively inhibit the pressure peak value of the single-wheel suspension under the impact action through balanced communication, improves the working environment of an actuating mechanism and improves the reliability. In addition, the traditional vehicle posture adjusting system is usually an open-loop constant-pressure system, while the invention provides a pressure self-feedback adjusting system, each group of oil circuits can adaptively adjust the opening of a throttle valve according to the change of load pressure, the redistribution of flow is realized, and the purpose of improving the stability and precision of vehicle posture adjustment is achieved.

Drawings

FIG. 1 is a schematic diagram of a five-axis vehicle load pressure self-feedback multistage damping adjustable balance suspension and cross-connection type vehicle posture adjusting system;

FIG. 2 is a schematic diagram of a single set of balanced suspension and cross-linked vehicle attitude adjustment system;

FIG. 3 is a schematic diagram of the main pressure control valve assembly;

FIG. 4 is a schematic diagram of an accumulator damper valve bank with a six-stage damping adjustable function;

FIG. 5 is a schematic diagram of a load pressure self-feedback attitude control valve set;

FIG. 6 is a schematic diagram of a one-way flow control valve with load pressure self-feedback function;

FIG. 7 is a schematic diagram of a system pressure control valve;

FIG. 8 is a structural and schematic diagram of a load pressure self-feedback flow regulating valve;

FIG. 9 is a schematic diagram of the overall control logic relationship of the system;

FIG. 10 is a flow chart of a static vehicle attitude and damping adjustment control method;

FIG. 11 is a flow chart of a dynamic vehicle attitude and damping adjustment control method;

fig. 12 is a flow chart of a damping adjustment control method.

Wherein: 1-main pressure control valve group, 2-left front accumulator damping valve group, 3-left front accumulator, 4-left front built-in displacement sensor, 5-left oil-gas spring, 6-front load pressure self-feedback vehicle attitude adjusting valve group, 7-left oil-gas spring, 8-system pressure control valve group, 9-left three oil-gas spring, 10-rear load pressure self-feedback vehicle attitude adjusting valve group, 11-left four oil-gas spring, 12-left rear built-in displacement sensor, 13-left five oil-gas spring, 14-left rear accumulator, 15-left rear accumulator damping valve group, 16-right rear accumulator damping valve group, 17-right rear accumulator, 18-right five oil-gas spring, 19-right rear built-in displacement sensor, 20-right four oil-gas spring, 21-right three oil-gas spring, 22-two right oil-gas springs, 23-one right oil-gas spring, 24-right front built-in displacement sensor, 25-right front accumulator vibration damping valve bank, 26-right front accumulator, 27-oil return filter, 28-power source and pump, 29-oil tank, 30-main oil filter, 31-hydraulic control pilot overflow valve, 32-two-position three-way direction control valve, 33-main pressure sensor, 34-main pressure defibrillation device, 35-one-way valve, 36-large damping two-way flow control valve, 37-large damper, 38-middle damper, 39-middle damping two-way flow control valve, 40-small damper, 41-small damping two-way flow control valve, 42-small damping electric control stop valve, 43-middle damping electric control stop valve, 44-large damping electric control stop valve, 45-A way oil return valve, 46-A way oil drain load pressure self-feedback flow regulating valve, 47-A way hydraulic lock, 48-A way oil charge load pressure self-feedback flow regulating valve, 49-B way hydraulic lock, 50-B way oil charge load pressure self-feedback flow regulating valve, 51-B way oil drain load pressure self-feedback flow regulating valve, 52-B way oil return valve, 53-B way oil charge valve, 54-A way oil charge valve, 55-vehicle posture oil return one-way valve, 56-front throttling defibrillation device, 57-system pressure comparison valve, 58-rear pressure comparison valve, 59-rear throttling defibrillation device, 60-front pressure comparison valve, 61-end cover, 62-valve body, 63-guide spring, 64-valve core, 65-reset spring, 66-top cover, 67-protective ring and 68-O-shaped ring.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The posture adjusting system of the multi-shaft vehicle is generally divided into four groups of a left front group, a right front group, a left rear group and a right rear group, each group consists of oil-gas springs with different numbers, wherein the oil-gas spring combination numbers of the left front group, the right front group, the left rear group and the right rear group are the same, oil-gas spring rodless cavities in each group are mutually communicated, rod cavities are also mutually communicated to form four groups of balanced suspensions, further, the rodless cavity of the left front oil-gas spring combination is communicated with the rod cavity of the right front oil-gas spring combination, the rod cavity of the left front oil-gas spring combination is communicated with the rodless cavity of the right front oil-gas spring combination, the rodless cavity of the left rear oil-gas spring combination is communicated with the rod cavity of the right rear oil-gas spring combination, the rod cavity of the left rear oil-gas spring combination is communicated with the rodless cavity of the right rear oil-gas spring combination, and the rodless cavities of the left front, right front, left rear and right rear, the anti-side-tipping interconnection type balance suspension of the whole vehicle is formed, all parts of the hydraulic system and the hydro-pneumatic suspension are connected through high-pressure hard pipes (or hoses), and the electric control device is connected with the electromagnetic valve bank of the hydraulic system through a cable to provide control signals.

The hydraulic system can select a matched balance suspension and cross interconnection type vehicle posture adjusting system according to the requirements of the vehicle on roll rigidity and load distribution; according to the requirement of the lifting stability of the vehicle, a matched load pressure self-feedback flow regulating valve and a manually-adjusted mechanical flow control valve group can be selected; whether the matched energy accumulator vibration reduction valve set has the multistage damping adjustable function or not can be selected according to the requirements of the vehicle on the adaptability of different road surfaces. A plurality of integrated control valves can be combined randomly by a person skilled in the art according to actual needs to realize the adjustment of the vehicle posture.

The system principle is illustrated below by taking a five-axis vehicle posture adjusting system as an example, as shown in fig. 1, the multi-axis vehicle posture adjusting system of the invention mainly comprises a main pressure control valve group 1, a left front accumulator damping valve group 2, a left front accumulator 3, a left front built-in displacement sensor 4, a left hydro-pneumatic spring 5, a front load pressure self-feedback vehicle posture adjusting valve group 6, a left hydro-pneumatic spring 7, a system pressure control valve group 8, a left three hydro-pneumatic springs 9, a rear load pressure self-feedback vehicle posture adjusting valve group 10, a left four hydro-pneumatic spring 11, a left rear built-in displacement sensor 12, a left five hydro-pneumatic spring 13, a left rear accumulator 14, a left rear accumulator damping valve group 15, a right rear accumulator damping valve group 16, a right rear accumulator 17, a right five hydro-pneumatic spring 18, a right rear built-in displacement sensor 19, a right four hydro-pneumatic spring 20, a right three hydro-pneumatic spring 21, a right two hydro-pneumatic spring 22, a right hydro-, a right front built-in displacement sensor 24, a right front accumulator damping valve group 25, a right front accumulator 26, an oil return filter 27, a power source and pump 28 and an oil tank 29. The left front built-in displacement sensor 4 is installed inside the left hydro-pneumatic spring 5, the left rear built-in displacement sensor 12 is installed inside the left five hydro-pneumatic spring 13, the right front built-in displacement sensor 24 is installed inside the right hydro-pneumatic spring 23, the right rear built-in displacement sensor 19 is installed inside the right five hydro-pneumatic spring 18, the displacement sensors can also be externally arranged at the suspension swing arm, namely, the hydro-pneumatic springs at the four farthest end points of the left front, the right front, the left rear and the right rear of the whole vehicle are respectively provided with the displacement sensors, so that the posture precision adjustment is convenient, and all the built-in displacement sensors are connected with a system controller through led-out control lines. The left front energy accumulator 3 is arranged on an Ac oil outlet of the left front energy accumulator damping valve group 2; the left rear energy accumulator 14 is arranged on an Ac oil outlet of the left rear energy accumulator damping valve group 15; the right rear energy accumulator 17 is installed on an Ac oil outlet of the right rear energy accumulator damping valve group 16, the right front energy accumulator 26 is installed on an Ac oil outlet of the right front energy accumulator damping valve group 25, and it should be noted that when the energy accumulators are connected with the corresponding energy accumulator damping valve groups, the energy accumulators can be connected with the valve groups through pipelines for convenience of arrangement, but the lengths of the pipelines should be reduced as much as possible, and pressure loss is reduced. An oil suction port of the power source and pump 28 is connected with an oil outlet of the oil tank 29, an oil inlet of P1 of the main pressure control valve group 1 is connected with an oil outlet of the power source and pump 28, and pressure oil at an outlet of the pump enters the system after being regulated by the main pressure control valve group 1. The oil outlet P of the main pressure control valve group 1 is simultaneously connected with the Pa control ports of the left front energy accumulator damping valve group 2, the left rear energy accumulator damping valve group 15, the right rear energy accumulator damping valve group 16 and the right front energy accumulator damping valve group 25 through pipelines to provide hydraulic control force for damping adjustment; the oil outlet P of the main pressure control valve group 1 is also connected with the oil inlet P of the front load pressure self-feedback turning posture adjusting valve group 6 and the rear load pressure self-feedback turning posture adjusting valve group 10 through pipelines to charge oil for the oil-gas spring. The rodless cavity of the left hydro-pneumatic spring 5 is connected with the rodless cavity of the left hydro-pneumatic spring 7 through a pipeline to form a left front balance suspension, and then is connected with an As oil outlet of the left front energy accumulator damping valve group 2, and the left front balance suspension is damped and the damping magnitude of the left front balance suspension is adjusted through the left front energy accumulator damping valve group 2; the rodless cavities of the left three oil-gas springs 9, the rodless cavities of the left four oil-gas springs 11 and the rodless cavities of the left five oil-gas springs 13 are connected through pipelines to form a left rear balanced suspension, and then are connected with the As oil outlet of the left rear energy accumulator damping valve group 15, and the left rear balanced suspension is damped and the damping magnitude of the damping is adjusted through the left rear energy accumulator damping valve group 15; the rodless cavity of the right hydro-pneumatic spring 23 is connected with the rodless cavity of the right hydro-pneumatic spring 22 through a pipeline to form a right front balance suspension, and then is connected with an As oil outlet of a right front energy accumulator damping valve group 25, and the right front balance suspension is damped and the damping magnitude of the right front balance suspension is adjusted through the right front energy accumulator damping valve group 25; the rodless cavities of the three right hydro-pneumatic springs 21, the rodless cavities of the four right hydro-pneumatic springs 20 and the rodless cavities of the five right hydro-pneumatic springs 18 are connected through pipelines to form a rear right balanced suspension, and then are connected with the As oil outlet of the rear right energy accumulator damping valve group 16, and the rear right balanced suspension is damped and the damping magnitude of the rear right balanced suspension is adjusted through the rear right energy accumulator damping valve group 16. The rod cavity of the left hydro-pneumatic spring 5 is connected with the rod cavity of the left hydro-pneumatic spring 7 through a pipeline and then connected with the right front balance suspension; the rod cavity of the right hydro-pneumatic spring 23 is connected with the rod cavity of the right hydro-pneumatic spring 22 through a pipeline and then connected with the left front balance suspension; the rod cavities of the left three hydro-pneumatic springs 9, the rod cavities of the left four hydro-pneumatic springs 11 and the rod cavities of the left five hydro-pneumatic springs 13 are connected through pipelines and then connected with the right rear balance suspension; the rod cavities of the right three hydro-pneumatic springs 21, the rod cavities of the right four hydro-pneumatic springs 20 and the rod cavities of the right five hydro-pneumatic springs 18 are connected through pipelines and then connected with the left rear balance suspension. The A oil outlet of the front load pressure self-feedback car posture adjusting valve group 6 is connected with a left front balance suspension, the B oil outlet is connected with a right front balance suspension, the T oil return port is connected with an oil return port of the oil tank 29, the Ka port is connected with the left front balance suspension, the Kb port is connected with the right front balance suspension, the Ka port and the Kb port serve as load pressure feedback interfaces of the valve group, an internal pressure feedback loop is formed by collecting load pressures of the left front balance suspension and the right front balance suspension, and the stability of suspension lifting of two sides is controlled. The A oil-out of back load pressure self feedback car appearance governing valve group 10 hangs continuously with left back balance, the B oil-out hangs continuously with right back balance, the T oil return opening passes through the T oil return opening of main pressure control valves 1 and links to each other with oil tank 29 oil return opening, Ka mouthful links to each other with left back balance, Kb mouthful links to each other with right back balance, Ka mouthful and Kb mouthful load pressure feedback interface as the valves, hang load pressure formation internal pressure feedback return circuit through gathering left back and right back balance, the stationarity that the control both sides hung the lift. The Fa end of a system pressure control valve group 8 is connected with a left front balance suspension to collect load pressure at the left front part of a vehicle, the Fb end is connected with a right front balance suspension to collect load pressure at the right front part of the vehicle, the Ra end is connected with a left rear balance suspension to collect load pressure at the left rear part of the vehicle, the Rb end is connected with a right rear balance suspension to collect load pressure at the right rear part of the vehicle, after the load pressure at each part is compared with the internal pressure of the system pressure control valve group 8, the maximum load pressure of the whole vehicle is output through a PLs port, the PLs port is connected with a pressure feedback LS port of a main pressure valve group 1, the maximum load pressure is input through the LS port to be control pressure for controlling the maximum actual working pressure of the whole system, so that the actual working pressure of the whole system is always higher than the maximum load pressure by 0.6-. The As oil outlet and the Ac oil outlet of the left front energy accumulator damping valve group 2, the left rear energy accumulator damping valve group 15, the right rear energy accumulator damping valve group 16 and the right front energy accumulator damping valve group 25 are communicated through damping flow control valves.

FIG. 2 is a schematic diagram of a single set of balanced suspension and cross-linked vehicle attitude adjustment system. The rodless cavity of the first left hydro-pneumatic spring 5 is connected with the rodless cavity of the second left hydro-pneumatic spring 7 through a pipeline to form a left front balance suspension; the rodless cavity of the right hydro-pneumatic spring 23 is connected with the rodless cavity of the right hydro-pneumatic spring 22 through a pipeline to form a right front balanced suspension, the effect of the balanced suspension is mainly used for balancing the internal pressure of each wheel suspension cylinder, the phenomenon of overload impact is avoided, and the system reliability is improved. For example, when the piston rod of the left hydro-pneumatic spring 5 is impacted to contract, the height of the vehicle body at the corresponding position is increased due to the impact of the hydro-pneumatic spring piston rod, and simultaneously, the pressure in the rodless cavity of the left hydro-pneumatic spring 5 is increased suddenly, when the vehicle is not suspended in a balanced manner, the vehicle body is only increased suddenly at the position, so that the vehicle posture is rocked, even the vehicle frame is twisted, and the axle and other parts of the vehicle suspension are damaged. When the vehicle adopts balanced suspension, because the rodless cavities of the front hydro-pneumatic spring and the rear hydro-pneumatic spring are communicated with each other, high-pressure oil in the rodless cavity of the left hydro-pneumatic spring 5 can be pressed into the rodless cavity of the left hydro-pneumatic spring 7, and the pressure in the rodless cavity of the left hydro-pneumatic spring 7 rises, so that the piston rod of the hydro-pneumatic spring can be driven to extend out in a follow-up manner, the balance of the vehicle body on the same side rises, the torsion of the vehicle frame is reduced, and the. The rod cavity of the left hydro-pneumatic spring 5 is connected with the rod cavity of the left hydro-pneumatic spring 7 through a pipeline and then is connected with the right front balance suspension to form cross interconnection; the rod cavity of the right hydro-pneumatic spring 23 and the rod cavity of the right hydro-pneumatic spring 22 are connected with the left front balance suspension through pipelines to form cross interconnection. The cross-linking function is mainly to reduce the excessive deflection of the vehicle body caused by uneven loads on the left side and the right side of the vehicle. For example, when the vehicle turns right, the left side of the unassembled cross-connected vehicle is subjected to large stress, the hydro-pneumatic spring piston rod is contracted, the vehicle body can generate large side inclination, and the vehicle can generate side overturning in severe cases; and the vehicle of assembly cross interconnection, when the left side atress was great, the hydro-pneumatic spring piston rod shrink, and left side hydro-pneumatic spring does not have the pole intracavity pressure and risees, and high-pressure oil gets into the right side along cross interconnection system and has the pole chamber, and the right side hydro-pneumatic spring is owing to there is the pole chamber pressure to rise, and the piston rod shrink for the passive compression of right side hydro-pneumatic spring causes the decline of right side automobile body certain degree, reduces the angle that the automobile body heeled, reduces the risk that the vehicle turned on one. It should be noted that the number of hydro-pneumatic springs included in the single set of balanced suspensions and cross-connects is related to the actual condition of the vehicle, and those skilled in the art can group the springs according to the actual load distribution of the vehicle.

Fig. 3 is a schematic diagram of a main pressure control valve assembly. The main pressure control valve group 1 is composed of a main oil filter 30, a pilot operated overflow valve 31, a two-position three-way directional control valve 32, a main pressure sensor 33, a main pressure defibrillation device 34 and a one-way valve 35. The main oil filter 30 is sequentially connected with the two-position three-way directional control valve 32 from an oil inlet P1 port to an oil outlet P port of the main pressure control valve group 1, the oil outlet of the two-position three-way directional control valve 32 is connected with the check valve 35 in series and then is connected with a T1 port of the main pressure control valve group 1, oil return is facilitated, oil liquid of an oil tank is prevented from flowing backwards, a pressure port of the two-position three-way directional control valve 32 is connected with the oil inlet P port of the main pressure control valve group 1 and is connected with the main pressure sensor 33, and system working pressure is conveniently; the hydraulic control pilot overflow valve 31 is connected in parallel with the two-position three-way directional control valve 32 and used for controlling the working pressure of the system, a hydraulic pilot control port of the hydraulic control pilot overflow valve 31 is reset in the same direction as the pressure of the valve core spring and is connected with an LS port of the main pressure control valve group 1 and used for receiving a system maximum pressure feedback signal, the system pressure entering the hydraulic control pilot overflow valve 31 is equal to the sum of the pressure of the hydraulic pilot control port and the back pressure spring force of the internal valve core, and therefore the purpose that the system pressure is only 0.6-0.9 MPa higher than the maximum load pressure all the time is achieved.

Fig. 4 is a schematic diagram of an accumulator damping valve bank with a six-stage damping adjustable function. The energy accumulator vibration reduction valve group 2 is a three-group parallel six-stage damping adjustable control system consisting of a large damping two-way flow control valve 36, a large damper 37, a large damping electric control stop valve 44, a middle damper 38, a middle damping two-way flow control valve 39, a middle damping electric control stop valve 43, a small damper 40, a small damping two-way flow control valve 41 and a small damping electric control stop valve 42, wherein the large damping electric control stop valve 44, the middle damping electric control stop valve 43 and the small damping electric control stop valve 42 are identical in structure and are usually two-position two-way cartridge valves, and the large damping two-way flow control valve 36, the middle damping two-way flow control valve 39 and the small damping two-way flow control valve 41 are identical. The large damper 37, the large damping two-way flow control valve 36 and the large damping electric control stop valve 44 are sequentially connected to form a large damping control oil path; the middle damper 38, the middle damping two-way flow control valve 39 and the middle damping electric control stop valve 43 are sequentially connected to form a middle damping control oil path; the small damper 40, the small damping two-way flow control valve 41 and the small damping electric control stop valve 42 are sequentially connected to form a small damping control oil path. Each two-way flow control valve comprises a control port and two oil outlets of As and Ac, the As and Ac ports are also oil outlets of the energy accumulator damping valve group, the control port is connected with an electric control stop valve, the As port in the two oil outlets is connected with the group of hydro-pneumatic springs, the Ac port is connected with an energy accumulator, and the electric control stop valve is connected with system pressure through an oil inlet Pa port of the energy accumulator damping valve group; when the control port of the two-way flow control valve is communicated with system pressure oil through the electric control stop valve, the As oil outlet and the Ac oil outlet are disconnected, so that the energy accumulator and the oil-gas spring cannot be communicated, and rigid locking is formed. It should be noted that the present invention can realize the adjustment of 6 damping characteristics by the respective on-off control of the large, medium and small damping electrically controlled stop valves, and it is not obvious for a person skilled in the art that the specific number of the damping control oil passages can also be determined by the actual use condition of the vehicle, and the parameter matching of the specific damper is also related to the actual use condition and requirement of the vehicle, and can be flexibly configured. The difference in orifice diameter between the large damper 37 and the medium damper 38, and the difference in orifice diameter between the medium damper 38 and the small damper 40 are not more than 2 mm.

Fig. 5 is a schematic diagram of a load pressure self-feedback vehicle attitude adjusting valve set. The front load pressure self-feedback vehicle posture adjusting valve group 6 and the rear load pressure self-feedback vehicle posture adjusting valve group 10 have the same structural principle, and the front load pressure self-feedback vehicle posture adjusting valve group 6 is specifically explained below. The front load pressure self-feedback vehicle posture adjusting valve group 6 consists of an A-way oil return valve 45, an A-way oil drain flow adjusting valve 46, an A-way hydraulic lock 47, an A-way oil charge flow adjusting valve 48, a B-way hydraulic lock 49, a B-way oil charge flow adjusting valve 50, a B-way oil drain flow adjusting valve 51, a B-way oil return valve 52, a B-way oil charge valve 53, an A-way oil charge valve 54 and a vehicle posture oil return one-way valve 55, is divided into an A-way oil circuit and a B-way oil circuit, and can be connected with different oil gas springs or balanced suspensions.

The A path oil filling flow regulating valve 48, the A path oil discharging flow regulating valve 46, the B path oil filling flow regulating valve 50 and the B path oil discharging flow regulating valve 51 are all one-way flow regulating valves with load pressure self-feedback function, the basic principle and the structural form are the same, as shown in figure 6, only when in use, the flow of the oil in different directions is controlled through different connection modes and combinations, a valve core and a valve body in the one-way flow regulating valve are both in a conical structure, the angle of the oblique angle of the valve body is slightly larger, the purpose is to realize the one-way flow regulating function, the one-way flow regulating valve P2 is an input end, the P1 is an output end, the oil inlet and the oil outlet in a controlled oil path are respectively connected, the K1 and the K2 are two external pressure control ends, the K2 end and the valve core spring pressure are reset in the same direction, the K1 end controls the flow regulating valve, when the load self-feedback control device is used, the ends K1 and K2 are respectively connected with corresponding load pressure according to requirements, and the opening degree of the flow valve is controlled through the load self pressure to form load self-feedback control.

The A-way oil discharge flow regulating valve 46 and the A-way oil charge flow regulating valve 48 are reversely connected in parallel to form a bidirectional flow regulating valve group, namely, the input end P2 of the A-way oil discharge flow regulating valve 46 is connected with the output end P1 of the A-way oil charge flow regulating valve 48, the output end P1 of the A-way oil discharge flow regulating valve 46 is connected with the input end P2 of the A-way oil charge flow regulating valve 48, the control end K1 of the A-way oil discharge flow regulating valve 46 and the control end K2 of the A-way oil charge flow regulating valve 48 are communicated with the end Ka of the load connected with the A-way through an internal oil circuit of the valve group to form a self-feedback control oil circuit of load pressure, the control end K2 of the A-way oil discharge flow regulating valve 46 and the control end K1 of the A-way oil charge flow regulating valve 48 are connected with the end Kb of the B-way through an internal oil circuit of the valve group to form another self-feedback control oil circuit of, when the load is reduced, the flow of the load on the A path is reduced; if the load of the path A is smaller than the load of the path B on the opposite side of the same axis, the flow of the load of the path A is reduced when the load of the path A rises, and the flow of the load of the path A is increased when the load of the path A falls.

The B-path oil discharge flow regulating valve 51 and the B-path oil filling flow regulating valve 50 are reversely connected in parallel to form a bidirectional flow regulating valve group, namely, the input end P2 of the B-path oil discharge flow regulating valve 51 is connected with the output end P1 of the B-path oil filling flow regulating valve 50, the output end P1 of the B-path oil discharge flow regulating valve 51 is connected with the input end P2 of the B-path oil filling flow regulating valve 50, the control end K1 of the B-path oil discharge flow regulating valve 51 and the control end K2 of the B-path oil filling flow regulating valve 50 are connected with the end Kb of the load connected with the B-path through an internal oil circuit of the valve group to form a load pressure self-feedback control oil circuit of one path, the control end K2 of the B-path oil discharge flow regulating valve 51 and the control end K1 of the B-path oil filling flow regulating valve 50 are connected with the end Ka of the load connected with the A-path through an internal oil circuit to form a load pressure self-feedback, when the load is reduced, the flow of the load on the B path is reduced; if the load on the B path is smaller than the load on the A path, the flow of the load on the B path is reduced when the load on the B path rises, and the flow of the load on the B path is increased when the load on the B path falls.

The inlet of the A path oil filling valve 54 is connected with the inlet of the B path oil filling valve 53, and then is connected with the input end P port of the front load pressure self-feedback vehicle posture adjusting valve group 6 through the internal oil path of the valve group to form an oil supply end of A, B two oil paths; the oil outlet of the a-way oil return valve 45 is connected with the oil outlet of the B-way oil return valve 52, then is connected with the vehicle posture oil return one-way valve 55 in series, and is connected with the oil return T port of the front load pressure self-feedback vehicle posture adjusting valve group 6 through the internal oil way of the valve group to form oil return ends of A, B two oil ways. The purpose of the tandem vehicle attitude oil return check valve 55 is to prevent oil in the oil tank from flowing backwards to influence the normal operation of the system.

The A path hydraulic lock 47, the two-way flow regulating valve group and the A path oil filling valve 54 are sequentially connected in series to form an A path oil inlet path, and the A path hydraulic lock 47, the two-way flow regulating valve group and the A path oil return valve 45 are sequentially connected in series to form an A path oil return path; the B-path hydraulic lock 49, the two-way flow regulating valve set and the B-path oil filling valve 53 are sequentially connected in series to form a B-path oil inlet path, and the B-path hydraulic lock 49, the two-way flow regulating valve set and the B-path oil return valve 52 are sequentially connected in series to form a B-path oil return path. The path a hydraulic lock 47, the path a oil filling valve 54, the path a oil return valve 45, the path B hydraulic lock 49, the path B oil filling valve 53, and the path B oil return valve 52 are two-position two-normally closed electromagnetic valves, and are powered on when oil is required to be filled or drained, so as to reduce power loss.

Fig. 7 is a schematic diagram of the system pressure control valve 8. The system pressure control valve 8 is comprised of a front throttle defibrillation device 56, a system pressure comparison valve 57, a rear pressure comparison valve 58, a rear throttle defibrillation device 59, and a front pressure comparison valve 60. Two input ends Fa and Fb of the front pressure comparison valve 60 are respectively connected with hydro-pneumatic springs or balance suspensions on two sides of the front part of the vehicle; two input terminals Ra and Rb of the rear pressure comparison valve 58 are connected to hydro-pneumatic springs on both sides of the rear of the vehicle, respectively. The output of the front pressure comparison valve 60 is connected in series with the front-throttle defibrillation device 56 and then to one input of the system pressure comparison valve 57, and the output of the rear pressure comparison valve 58 is connected in series with the rear-throttle defibrillation device 59 and then to the other input of the system pressure comparison valve 57. After the load pressures at the two sides of the front part are compared by a front pressure comparison valve 60, the higher pressure is subjected to noise reduction and defibrillation by a front throttling defibrillation device 56 and enters one input end of a system pressure comparison valve 57, after the load pressures at the two sides of the rear part are compared by a rear pressure comparison valve 58, the higher pressure is subjected to noise reduction and defibrillation by a rear throttling defibrillation device 59 and enters the other input end of the system pressure comparison valve 57, the two higher load pressures at the front and the rear part pass through the system pressure comparison valve 57 and are compared to find the maximum load of the vehicle, the maximum load is transmitted to a PLs port of a system pressure control valve 8 through the output end of the system pressure comparison valve 57 and then is connected with a pressure feedback LS port of a main pressure control valve bank 1, and the maximum load pressures are subjected to noise reduction and defibrillation by a main pressure defibrillation device 34 and then are input to a, the real-time correlation between the actual working pressure of the system and the highest load of the system is realized, and the pressure loss caused by the no-load of the system is reduced.

Fig. 8 is a structure and a schematic diagram of a load pressure self-feedback flow control valve, and the structures of all the load pressure self-feedback flow control valves in the system are the same. The load pressure self-feedback flow regulating valve consists of an end cover 61, a valve body 62, a guide spring 63, a valve core 64, a return spring 65, a top cover 66, a protective ring 67 and an O-shaped ring 68. The valve can be an external independent flow regulating device, and can also be embedded in the valve bank to form a component of the valve bank. The valve core 64 is assembled in a central hole of the valve body 62, a conical surface sealing structure is adopted, one end of the valve body 62 is provided with an end cover 61, the other end of the valve body 62 is provided with a top cover 66, the central hole of the end cover 61 is a K1 control end of the load pressure self-feedback flow regulating valve, the central hole of the top cover 66 is a K2 control end of the load pressure self-feedback flow regulating valve, a K1 control end and a K2 control end are opposite and are positioned on the axis of the valve core 64, two protection rings 67 are respectively arranged on two sides of an O-shaped ring 68 and are assembled in a sealing groove of the end cover 61 and are matched with a guide column of the valve core 64 to isolate a pressure medium of the K1 control end and a P1 output end, and the. The control end of K1, the output end of P1 and the guide spring 63 are all arranged at one end with a large diameter of the conical valve core 64, and are supported and limited by the end cover 61, the function of the end cover is to provide locking pressure of the valve core 64 and simultaneously play a role of guiding the valve core 62, and the rigidity and the precompression of the guide spring 63 are related to the working pressure of the system. An O-ring 68 and a protection ring 67 distributed on two sides of the O-ring are also assembled in the sealing groove of the valve body 62, and are matched with the valve core 64 for isolating the pressure medium of the control end of the K2 and the input end P2, and the top cover 66 is used as a supporting limit of the return spring 65 and is connected to the other end of the valve body 62. The K2 control end, the input end P2 and the return spring 65 are all arranged at one end of the small diameter of the conical valve core 64, the return spring 65 is arranged in an inner hole of a guide column at the end of the small diameter of the valve core 64, the function of the return spring is to provide balanced pressure difference between the control ends K1 and K2, the function of the return spring is to provide pre-thrust for opening the valve core 64, and the rigidity and the pre-compression amount of the return spring 65 are related to the working pressure of the system. When the valve core 64 normally works, the valve core 64 is pressed onto the valve body 62 under the action of the guide spring 63, and when the oil pressure flows from P1 to P2, the valve core 64 is locked due to the pressure difference, a passage is cut off, and the flow rate cannot be regulated; when the oil pressure flows from P2 to P1, the pressure difference pushes the valve core 64 to move, a passage is opened, the valve core 64 is controlled to move to a required force balance position through the comparison of the pressure of the K1 end and the pressure of the K2 end, a fixed annular gap throttling channel is formed at the conical surface between the valve core 64 and the valve body 62, the throttling area is in direct proportion to the evolution of the pressure difference between the load pressure and the system pressure, and the throttling effect is generated on the flowing oil. The taper hole of the valve body 62 has a slightly larger angle than the taper of the valve core 64 of the cone valve, so that the valve core 64 can be smoothly locked under the one-way action.

It should be noted that the compression rate of the O-ring 68 in cooperation with the valve core 64 generally needs to be controlled to be 16% -20%, and the pre-tightening force value of the guide spring 63 should be greater than that of the return spring 65, so as to ensure that the valve core is effectively locked to avoid an internal leakage phenomenon; the axes of the P1 output and P2 inputs are designed to be generally perpendicular to the axis of the spool 64; the K1 control port and the pilot spring 63 serve to decrease the opening degree of the spool 64, and the K2 control port and the return spring 65 serve to increase the opening degree of the spool 64.

FIG. 9 is a schematic diagram of the general control logic relationship of the vehicle attitude control system of the present invention. The system uses a motor (or an engine) and a pump as power sources to provide high-pressure power, uses an oil-gas suspension as an execution element, and acquires the maximum working load of each wheel as the actual working pressure of the system through a system internal pressure self-feedback system so as to achieve the purpose of saving energy of the system; the controller downloads information such as vehicle speed and the like through a bus, collects parameters such as hydro-pneumatic suspension pressure, displacement and speed, calculates parameters such as hydro-pneumatic spring displacement change by combining a system algorithm, adjusts damping and rigidity characteristics of the hydro-pneumatic suspension in real time and vehicle height to form closed-loop control, and improves vehicle trafficability, operation stability and comfort. Meanwhile, when the height of the vehicle body is adjusted, the flow of each part of the system is controlled through the internal pressure self-feedback system, the lifting stability of the vehicle is kept, the flow of each wheel position is reasonably distributed, and the purpose of stable lifting is achieved.

FIG. 10 is a flow chart of a static vehicle attitude and damping adjustment control method. The method comprises the following steps:

the first step is as follows: when a driver pulls a corresponding adjusting button, the system enters a self-checking state, and whether the vehicle can enter a vehicle posture and damping static adjusting program is judged by acquiring a vehicle speed signal;

the second step is that: when the vehicle speed is less than 10km/h, judging that the regulation requirement is met, entering a next static regulation program, and when the vehicle speed is more than 10km/h, judging that the regulation requirement is not met, entering a dynamic regulation program;

the third step: the system collects pressure signals of each wheel of hydro-pneumatic spring and position signals of the oil cylinder;

the fourth step: the system judges whether the pressure of the single wheel exceeds the limit or not according to the pressure information, if the pressure exceeds the limit, the system initial damping is set to be heavy-load cross-country damping, if the pressure does not exceed the limit, the system initial damping is set to be no-load cross-country damping, and the system initial damping is matched with the sprung mass and the suspension stiffness of the vehicle according to a relative damping coefficient of 0.25;

the fifth step: the system adjusts the static height of the vehicle posture according to the action requirement input by the driver, judges whether the vehicle posture height is in place or not by acquiring displacement signals of the wheel displacement oil cylinders in real time, finishes the adjustment if the vehicle posture height is in place, and returns to the third step if the vehicle posture height is not in place.

FIG. 11 is a flow chart of a dynamic vehicle attitude and damping adjustment control method, which is implemented as follows:

the first step is as follows: when a driver pulls a corresponding adjusting button, the system enters a self-checking state, and whether the vehicle can enter a vehicle posture and damping dynamic adjusting program is judged by acquiring a vehicle speed signal;

the second step is that: when the vehicle speed is more than 10km/h, judging that the regulation requirement is met, entering a next dynamic regulation program, and when the vehicle speed is less than 10km/h, judging that the regulation requirement is not met, entering a static regulation program;

the third step: taking a specified driving distance of 500m as a sampling period, and calculating sampling time according to the sampling period;

the fourth step: the system respectively carries out dynamic adjustment of the posture of the vehicle body and semi-active adjustment of the damping in the sampling time;

when the vehicle body posture is dynamically adjusted, the system extracts the stroke and the internal pressure change of each wheel of hydro-pneumatic spring according to the sampling frequency of 20Hz-30Hz, respectively calculates the arithmetic mean value and the root mean square value of the stroke and the pressure change of the hydro-pneumatic spring within the set time, compares the arithmetic mean value and the root mean square value with the vehicle body height at the initial static balance position to obtain the vehicle posture height variation caused by the influence of factors such as suspension temperature rise and the like in the vehicle driving process, finally executes corresponding adjusting action according to the set program setting, and compares the data of the corresponding displacement sensor with a target value in real time until the required vehicle posture height is reached;

when damping semi-active adjustment is carried out, the system extracts stroke changes of each wheel of hydro-pneumatic springs in sampling time according to the sampling frequency of 20Hz-30Hz, power spectral density data processing is carried out in a frequency domain to judge the grade of the road surface, and damping characteristics are optimized according to the grade of the road surface; the system simultaneously extracts pressure changes of each wheel of hydro-pneumatic springs within sampling time according to the sampling frequency of 20Hz-30Hz, judges whether the vehicle is in a no-load or heavy-load state according to whether the single-wheel load is overloaded, judges whether initial damping setting meets requirements or not by combining the load state of the vehicle and the optimized damping characteristic, if so, the system is finished, and if not, the system opens and closes a corresponding damping control valve and selects a corresponding damping size.

The method is characterized in that a small damping mode is adopted on a good high-frequency road surface, a large damping mode is adopted on a low-frequency and large-fluctuation dirt road surface and a cross-country road surface, and a suspension damping force value is adjusted to enable a vehicle to reach an ideal running state.

Fig. 12 is a flow chart of a damping adjustment control method, which implements the following steps:

the first step is as follows: collecting load signals of each wheel of hydro-pneumatic spring after the system is electrified;

the second step is that: the system judges whether the pressure of the single wheel exceeds the limit or not through the load signal, if the pressure exceeds the limit, the system initial damping is set to be heavy-load cross-country damping, if the pressure does not exceed the limit, the system initial damping is set to be no-load cross-country damping, and the system initial damping is matched with the sprung mass and the suspension stiffness of the vehicle according to a relative damping coefficient of 0.25;

the third step: the system collects a vehicle speed signal, takes a specified driving distance of 500m as a sampling period, and calculates sampling time according to the sampling period;

the fourth step: the system extracts stroke changes of each wheel of hydro-pneumatic spring in sampling time according to the sampling frequency of 20Hz-30Hz, performs power spectral density data processing in a frequency domain to judge the grade of the road surface, and optimizes the damping characteristic according to the grade of the road surface; the system simultaneously extracts the pressure change of each wheel of hydro-pneumatic spring in sampling time according to the sampling frequency of 20Hz-30Hz, and judges whether the vehicle is in a no-load or heavy-load state according to whether the single-wheel load is overloaded;

the fifth step: the system judges whether the initial damping setting meets the requirements or not by combining the vehicle load state and the optimized damping characteristic, if so, the system is ended, if not, the system opens and closes the corresponding damping control valve, and selects the corresponding damping size.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.