阅读说明：本技术 一种基于摇臂悬架的压力-位移综合控制系统及方法 (Pressure-displacement comprehensive control system and method based on rocker arm suspension ) 是由 薛涛 杨勇 金昊龙 宋慧新 徐广龙 陈宇 于 2020-06-17 设计创作，主要内容包括：本发明提供了一种基于摇臂悬架的压力-位移综合控制系统及方法,控制系统包括摇臂悬架、液压系统、角位移传感器、压力传感器及控制器；控制器通过角位移传感器采集到的摇臂悬架的摇臂位置和压力传感器采集到的油腔压力,判断摇臂悬架的状态：处于承载腔静载压力增大方向或者减小方向；控制器根据摇臂悬架的状态控制液压系统推动摇臂旋转到设定的目标位置并协同调节承载腔压力调整到目标压力值,由此完成压力-位移综合控制。本发明能够提高摇臂悬架的控制稳定性、快速性和准确性。(The invention provides a pressure-displacement comprehensive control system and a pressure-displacement comprehensive control method based on a rocker arm suspension, wherein the control system comprises the rocker arm suspension, a hydraulic system, an angular displacement sensor, a pressure sensor and a controller; the controller judges the state of the rocker arm suspension through the rocker arm position of the rocker arm suspension collected by the angular displacement sensor and the oil cavity pressure collected by the pressure sensor: the static load pressure of the bearing cavity is increased or decreased; the controller controls the hydraulic system to push the rocker arm to rotate to a set target position according to the state of the rocker arm suspension and cooperatively adjusts the pressure of the bearing cavity to a target pressure value, so that pressure-displacement comprehensive control is completed. The invention can improve the control stability, rapidity and accuracy of the rocker arm suspension.)

1. A pressure-displacement integrated control system based on a rocker arm suspension is characterized by comprising a rocker arm suspension, a hydraulic system, an angular displacement sensor, a pressure sensor and a controller;

the input end of the controller is connected with the angular displacement sensor and the pressure sensor, and the output end of the controller is connected with the hydraulic system; the angular displacement sensor and the pressure sensor are connected with the rocker arm suspension; the hydraulic system is connected with the rocker arm suspension; the controller judges the state of the rocker arm suspension through the rocker arm position of the rocker arm suspension collected by the angular displacement sensor and the oil cavity pressure collected by the pressure sensor: the bearing cavity static load pressure is in the increasing direction or the decreasing direction; the controller controls the hydraulic system to push the rocker arm to rotate to a set target position according to the state of the rocker arm suspension and cooperatively adjusts the pressure of the bearing cavity to a target pressure value, the target pressure value is a static load pressure value required by the bearing cavity of each suspension under the real-time whole vehicle posture, if the required static load pressure value is smaller than a set threshold value, the target pressure value is a set threshold value, the set threshold value is a pressure value which is used for preventing displacement mutation caused by the change of the bearing cavity when the vertical position is crossed while the pushing force is ensured, and therefore pressure-displacement comprehensive control is completed.

2. The rocker arm suspension based integrated pressure-displacement control system of claim 1, wherein the hydraulic system comprises a hydraulic pump, a pressure-displacement control circuit, and a load feedback circuit;

the pressure-displacement control loop comprises a bidirectional electromagnetic directional valve, a left one-way proportional electromagnetic directional valve and a right one-way proportional electromagnetic directional valve; four oil ports of the bidirectional electromagnetic directional valve are respectively connected with an oil inlet of the right one-way proportional electromagnetic directional valve, an oil inlet of the left one-way proportional electromagnetic directional valve, an oil outlet of the fixed-differential pressure reducing valve and an oil tank; the oil outlet of the left one-way proportional electromagnetic directional valve is connected with oil cavities at the left upper part and the right lower part of the rocker arm suspension; the oil outlet of the right one-way proportional electromagnetic directional valve is connected with oil cavities at the upper right and lower left of the rocker arm suspension;

the load feedback loop comprises a differential pressure type overflow valve, a constant differential pressure reducing valve, a load pressure sensing shuttle valve and a safety valve; an oil inlet of a differential pressure overflow valve is connected with an oil outlet of the hydraulic pump, an oil outlet of the differential pressure overflow valve is connected with an oil inlet of a constant differential pressure reducing valve and an oil tank, and a control oil path of the differential pressure overflow valve is connected with a control oil path of the constant differential pressure reducing valve; three oil ports of the load pressure sensing shuttle valve are respectively connected with an oil control port of the fixed-difference pressure reducing valve, an oil outlet of the left one-way proportional electromagnetic directional valve and an oil outlet of the right one-way proportional electromagnetic directional valve.

3. A pressure-displacement integrated control method based on a rocker arm suspension, which is characterized in that the control system of claim 1 is adopted, and the control method comprises the following steps:

setting a target position of a rocker arm as a target value of position closed-loop control, simultaneously collecting real-time positions of all rocker arms of a whole vehicle to solve a real-time attitude of the whole vehicle, calculating static load pressure values required by all suspension bearing cavities under the corresponding real-time attitude, and taking the static load pressure values as target pressure values of pressure closed-loop control; when the required static load pressure value is smaller than a set threshold value, the target pressure value is the set threshold value, and the set threshold value is a pressure value which ensures the pushing force and prevents displacement mutation caused by the change of the bearing cavity when crossing the vertical position;

when the state of the rocker arm suspension is in a direction of increasing the static load pressure of the bearing cavity, the controller controls the hydraulic system to charge oil to the non-bearing cavity in proportion by taking the received angular displacement and the pressure values of the oil cavity bearing cavity and the non-bearing cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to reach a set target position to complete position closed-loop control; meanwhile, proportional oil drainage is carried out on the bearing cavity by controlling a hydraulic system, the pressure of the bearing cavity is controlled at a target pressure value, and pressure closed-loop control is completed;

When the state of the rocker arm suspension is in a direction of reducing the static load pressure of the bearing cavity, the controller controls the hydraulic system to charge oil to the bearing cavity in proportion by taking the received angular displacement and the pressure values of the oil cavity bearing cavity and the non-bearing cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to a set target position to perform position closed-loop control; meanwhile, the hydraulic system is controlled to discharge oil to the non-bearing cavity in proportion, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches a set target position, the controller controls the hydraulic system to independently perform proportional oil charging or discharging on the bearing cavity and the non-bearing cavity, the pressure of the bearing cavity and the pressure of the non-bearing cavity are adjusted to a target pressure value, and pressure closed-loop control is completed.

4. The rocker arm suspension based integrated pressure-displacement control method of claim 3, wherein the hydraulic system comprises a hydraulic pump, a pressure-displacement control circuit and a load feedback circuit;

the pressure-displacement control loop comprises a bidirectional electromagnetic directional valve, a left one-way proportional electromagnetic directional valve and a right one-way proportional electromagnetic directional valve; four oil ports of the bidirectional electromagnetic directional valve are respectively connected with an oil inlet of the right one-way proportional electromagnetic directional valve, an oil inlet of the left one-way proportional electromagnetic directional valve, an oil outlet of the fixed-differential pressure reducing valve and an oil tank; the oil outlet of the left one-way proportional electromagnetic directional valve is connected with oil cavities at the left upper part and the right lower part of the rocker arm suspension; the oil outlet of the right one-way proportional electromagnetic directional valve is connected with oil cavities at the upper right and lower left of the rocker arm suspension;

The load feedback loop comprises a differential pressure type overflow valve, a constant differential pressure reducing valve, a load pressure sensing shuttle valve and a safety valve; an oil inlet of a differential pressure overflow valve is connected with an oil outlet of the hydraulic pump, an oil outlet of the differential pressure overflow valve is connected with an oil inlet of a constant differential pressure reducing valve and an oil tank, and a control oil path of the differential pressure overflow valve is connected with a control oil path of the constant differential pressure reducing valve; three oil ports of the load pressure sensing shuttle valve are respectively connected with a fixed-difference pressure reducing valve control oil port, a left one-way proportional electromagnetic directional valve oil outlet and a right one-way proportional electromagnetic directional valve oil outlet;

the process of the hydraulic system for proportionally filling or discharging oil to the bearing cavity and the non-bearing cavity is as follows:

when the rocker arm suspension is in a state of clockwise rotation towards the static load pressure increasing direction of the bearing cavity, the controller turns the bidirectional electromagnetic directional valve to the left position and controls the size of the valve port of the left one-way proportional electromagnetic directional valve to perform proportional oil filling on the non-bearing cavity; meanwhile, the controller performs proportional oil drainage on the bearing cavity by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve;

when the rocker arm suspension is in an anticlockwise rotation state towards the static load pressure increasing direction of the bearing cavity, the controller drives the two-way electromagnetic directional valve to the right position and controls the valve port size of the right one-way proportional electromagnetic directional valve to perform proportional oil filling on the non-bearing cavity; meanwhile, the controller performs proportional oil drainage on the bearing cavity by controlling the size of the valve port of the left one-way proportional electromagnetic directional valve;

When the rocker arm suspension is in a state of rotating clockwise towards the direction of reducing the static load pressure of the bearing cavity, the controller turns the bidirectional electromagnetic directional valve to the left position and controls the size of the valve port of the left one-way proportional electromagnetic directional valve to perform proportional oil filling on the bearing cavity; meanwhile, proportional oil drainage is carried out on the non-bearing cavity by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches the target position, closing the right one-way proportional electromagnetic directional valve, controlling the direction of the two-way electromagnetic directional valve and the opening size of the left one-way proportional electromagnetic directional valve to discharge or charge oil to the bearing cavity until the pressure of the bearing cavity is adjusted to a target pressure value; after the pressure of the bearing cavity is adjusted, closing the left one-way proportional electromagnetic directional valve, and discharging or charging oil to the non-bearing cavity by controlling the direction of the two-way electromagnetic directional valve and the opening size of the right one-way proportional electromagnetic directional valve until the pressure of the non-bearing cavity is also adjusted to a target pressure value;

when the rocker arm suspension is in an anticlockwise rotation state towards the direction of reducing the static load pressure of the bearing cavity, the controller drives the two-way electromagnetic directional valve to the right position and controls the valve port size of the right one-way proportional electromagnetic directional valve to carry out proportional oil filling on the bearing cavity; meanwhile, proportional oil drainage is carried out on the non-bearing cavity by controlling the size of the valve port of the left one-way proportional electromagnetic directional valve, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches the target position, closing the left one-way proportional electromagnetic directional valve, controlling the direction of the two-way electromagnetic directional valve and the opening size of the right one-way proportional electromagnetic directional valve to discharge or charge oil to the bearing cavity until the pressure of the bearing cavity is adjusted to a target pressure value; and after the pressure of the bearing cavity is adjusted, closing the right one-way proportional electromagnetic directional valve, and discharging or charging oil to the non-bearing cavity by controlling the direction of the two-way electromagnetic directional valve and the opening size of the left one-way proportional electromagnetic directional valve until the pressure of the non-bearing cavity is also adjusted to a target pressure value.

Technical Field

The invention relates to the technical field of vehicle traveling systems, in particular to a pressure-displacement comprehensive control system and method based on a rocker arm suspension.

Background

Along with the development of unmanned platform technology, how to improve the adaptability and the trafficability of the unmanned platform to complex terrains gradually becomes an important development direction of a walking system of the unmanned platform, the rocker arm suspension is paid more and more attention with excellent obstacle crossing and trench crossing performance and becomes an urgent part of future unmanned vehicles and manned high-mobility platforms, and the U.S. two vehicle types MULE and CRUSHER relate to the rocker arm suspension technology and have strong obstacle crossing and trench crossing capability by virtue of the rocker arm suspension.

The principle of a rocker arm suspension based on the rack and pinion type is shown in fig. 1. The rack and pinion type rocker arm suspensions on two sides of the vehicle body are composed of a gear shaft, a lower rack assembly, an upper rack assembly, four oil cylinders, a left air cylinder E, a right air cylinder F and the like, and taking the rocker arm suspension on one side as an example, a rocker arm rotating shaft is taken as a center, an upper left oil cylinder hydraulic cavity is A, an upper right oil cylinder hydraulic cavity is B, an upper left oil cylinder hydraulic cavity is C, and a lower right oil cylinder hydraulic cavity is D. When the rocker rotates anticlockwise to drive the gear shaft to rotate anticlockwise, the upper rack assembly meshed with the gear shaft moves leftwards, so that the oil in the A, D hydraulic cavity is subjected to compression pressure to rise, and conversely, when the rocker rotates clockwise, the upper rack assembly moves rightwards, so that the oil in the B, C hydraulic cavity is subjected to compression pressure to rise. The load chamber is A, D when the rocker arm is in the state of FIG. 1(a), i.e., to the right of the centerline, and B, C when the rocker arm is in the state of FIG. 1(b), i.e., to the left of the centerline.

As shown in FIG. 2, when the rocker arm is at different positions, the load F of each wheel is caused by different vehicle postures of the whole vehicle_qUnevenly distributed while loading F_qThe torque arm Lsin alpha of the rocker arm is changed along with the change of the position of the rocker arm, so that a bearing cavity of the rocker arm suspension is caused The pressure changes in real time during the position adjustment process, and the problem of sudden change of the position of the rocker arm caused by the change of the bearing cavity when the rocker arm passes through the vertical position exists, which influences the stability and the accuracy of the position control. In the prior art, only position control is carried out, the rocker arm reaches a target position through oil filling, the target position corresponds to a corresponding pressure value, namely the static load pressure of a bearing cavity of a vehicle posture suspension, and when the oil filling is stopped, the pressure of the bearing cavity cannot reach the corresponding static load pressure, so that the position of the rocker arm is changed, and the position control is not accurate.

Disclosure of Invention

In view of the above, the invention provides a pressure-displacement comprehensive control system and method based on a rocker arm suspension, which improve the control stability, rapidity and accuracy of the rocker arm suspension.

The technical scheme adopted by the invention is as follows:

a pressure-displacement integrated control system based on a rocker arm suspension comprises the rocker arm suspension, a hydraulic system, an angular displacement sensor, a pressure sensor and a controller;

the input end of the controller is connected with the angular displacement sensor and the pressure sensor, and the output end of the controller is connected with the hydraulic system; the angular displacement sensor and the pressure sensor are connected with the rocker arm suspension; the hydraulic system is connected with the rocker arm suspension; the controller judges the state of the rocker arm suspension through the rocker arm position of the rocker arm suspension collected by the angular displacement sensor and the oil cavity pressure collected by the pressure sensor: the bearing cavity static load pressure is in the increasing direction or the decreasing direction; the controller controls the hydraulic system to push the rocker arm to rotate to a set target position according to the state of the rocker arm suspension and cooperatively adjusts the pressure of the bearing cavity to a target pressure value, the target pressure value is a static load pressure value required by the bearing cavity of each suspension under the real-time whole vehicle posture, if the required static load pressure value is smaller than a set threshold value, the target pressure value is a set threshold value, the set threshold value is a pressure value which is used for preventing displacement mutation caused by the change of the bearing cavity when the vertical position is crossed while the pushing force is ensured, and therefore pressure-displacement comprehensive control is completed.

Further, the hydraulic system includes a hydraulic pump, a pressure-displacement control circuit, and a load feedback circuit;

the pressure-displacement control loop comprises a bidirectional electromagnetic directional valve, a left one-way proportional electromagnetic directional valve and a right one-way proportional electromagnetic directional valve; four oil ports of the bidirectional electromagnetic directional valve are respectively connected with an oil inlet of the right one-way proportional electromagnetic directional valve, an oil inlet of the left one-way proportional electromagnetic directional valve, an oil outlet of the fixed-differential pressure reducing valve and an oil tank; the oil outlet of the left one-way proportional electromagnetic directional valve is connected with oil cavities at the left upper part and the right lower part of the rocker arm suspension; the oil outlet of the right one-way proportional electromagnetic directional valve is connected with oil cavities at the upper right and lower left of the rocker arm suspension;

the load feedback loop comprises a differential pressure type overflow valve, a constant differential pressure reducing valve, a load pressure sensing shuttle valve and a safety valve; an oil inlet of a differential pressure overflow valve is connected with an oil outlet of the hydraulic pump, an oil outlet of the differential pressure overflow valve is connected with an oil inlet of a constant differential pressure reducing valve and an oil tank, and a control oil path of the differential pressure overflow valve is connected with a control oil path of the constant differential pressure reducing valve; three oil ports of the load pressure sensing shuttle valve are respectively connected with an oil control port of the fixed-difference pressure reducing valve, an oil outlet of the left one-way proportional electromagnetic directional valve and an oil outlet of the right one-way proportional electromagnetic directional valve.

A pressure-displacement comprehensive control method based on a rocker arm suspension adopts the control system, and comprises the following steps:

setting a target position of a rocker arm as a target value of position closed-loop control, simultaneously collecting real-time positions of all rocker arms of a whole vehicle to solve a real-time attitude of the whole vehicle, calculating static load pressure values required by all suspension bearing cavities under the corresponding real-time attitude, and taking the static load pressure values as target pressure values of pressure closed-loop control; when the required static load pressure value is smaller than a set threshold value, the target pressure value is the set threshold value, and the set threshold value is a pressure value which ensures the pushing force and prevents displacement mutation caused by the change of the bearing cavity when crossing the vertical position;

when the state of the rocker arm suspension is in a direction of increasing the static load pressure of the bearing cavity, the controller controls the hydraulic system to charge oil to the non-bearing cavity in proportion by taking the received angular displacement and the pressure values of the oil cavity bearing cavity and the non-bearing cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to reach a set target position to complete position closed-loop control; meanwhile, proportional oil drainage is carried out on the bearing cavity by controlling a hydraulic system, the pressure of the bearing cavity is controlled at a target pressure value, and pressure closed-loop control is completed;

When the state of the rocker arm suspension is in a direction of reducing the static load pressure of the bearing cavity, the controller controls the hydraulic system to charge oil to the bearing cavity in proportion by taking the received angular displacement and the pressure values of the oil cavity bearing cavity and the non-bearing cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to a set target position to perform position closed-loop control; meanwhile, the hydraulic system is controlled to discharge oil to the non-bearing cavity in proportion, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches a set target position, the controller controls the hydraulic system to independently perform proportional oil charging or discharging on the bearing cavity and the non-bearing cavity, the pressure of the bearing cavity and the pressure of the non-bearing cavity are adjusted to a target pressure value, and pressure closed-loop control is completed.

Further, the hydraulic system includes a hydraulic pump, a pressure-displacement control loop, and a load feedback loop;

the pressure-displacement control loop comprises a bidirectional electromagnetic directional valve, a left one-way proportional electromagnetic directional valve and a right one-way proportional electromagnetic directional valve; four oil ports of the bidirectional electromagnetic directional valve are respectively connected with an oil inlet of the right one-way proportional electromagnetic directional valve, an oil inlet of the left one-way proportional electromagnetic directional valve, an oil outlet of the fixed-differential pressure reducing valve and an oil tank; the oil outlet of the left one-way proportional electromagnetic directional valve is connected with oil cavities at the left upper part and the right lower part of the rocker arm suspension; the oil outlet of the right one-way proportional electromagnetic directional valve is connected with oil cavities at the upper right and lower left of the rocker arm suspension;

The load feedback loop comprises a differential pressure type overflow valve, a constant differential pressure reducing valve, a load pressure sensing shuttle valve and a safety valve; an oil inlet of a differential pressure overflow valve is connected with an oil outlet of the hydraulic pump, an oil outlet of the differential pressure overflow valve is connected with an oil inlet of a constant differential pressure reducing valve and an oil tank, and a control oil path of the differential pressure overflow valve is connected with a control oil path of the constant differential pressure reducing valve; three oil ports of the load pressure sensing shuttle valve are respectively connected with a fixed-difference pressure reducing valve control oil port, a left one-way proportional electromagnetic directional valve oil outlet and a right one-way proportional electromagnetic directional valve oil outlet;

the process of the hydraulic system for proportionally filling or discharging oil to the bearing cavity and the non-bearing cavity is as follows:

when the rocker arm suspension is in a state of clockwise rotation towards the static load pressure increasing direction of the bearing cavity, the controller turns the bidirectional electromagnetic directional valve to the left position and controls the size of the valve port of the left one-way proportional electromagnetic directional valve to perform proportional oil filling on the non-bearing cavity; meanwhile, the controller performs proportional oil drainage on the bearing cavity by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve;

when the rocker arm suspension is in an anticlockwise rotation state towards the static load pressure increasing direction of the bearing cavity, the controller drives the two-way electromagnetic directional valve to the right position and controls the valve port size of the right one-way proportional electromagnetic directional valve to perform proportional oil filling on the non-bearing cavity; meanwhile, the controller performs proportional oil drainage on the bearing cavity by controlling the size of the valve port of the left one-way proportional electromagnetic directional valve;

When the rocker arm suspension is in a state of rotating clockwise towards the direction of reducing the static load pressure of the bearing cavity, the controller turns the bidirectional electromagnetic directional valve to the left position and controls the size of the valve port of the left one-way proportional electromagnetic directional valve to perform proportional oil filling on the bearing cavity; meanwhile, proportional oil drainage is carried out on the non-bearing cavity by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches the target position, closing the right one-way proportional electromagnetic directional valve, controlling the direction of the two-way electromagnetic directional valve and the opening size of the left one-way proportional electromagnetic directional valve to discharge or charge oil to the bearing cavity until the pressure of the bearing cavity is adjusted to a target pressure value; after the pressure of the bearing cavity is adjusted, closing the left one-way proportional electromagnetic directional valve, and discharging or charging oil to the non-bearing cavity by controlling the direction of the two-way electromagnetic directional valve and the opening size of the right one-way proportional electromagnetic directional valve until the pressure of the non-bearing cavity is also adjusted to a target pressure value;

when the rocker arm suspension is in an anticlockwise rotation state towards the direction of reducing the static load pressure of the bearing cavity, the controller drives the two-way electromagnetic directional valve to the right position and controls the valve port size of the right one-way proportional electromagnetic directional valve to carry out proportional oil filling on the bearing cavity; meanwhile, proportional oil drainage is carried out on the non-bearing cavity by controlling the size of the valve port of the left one-way proportional electromagnetic directional valve, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches the target position, closing the left one-way proportional electromagnetic directional valve, controlling the direction of the two-way electromagnetic directional valve and the opening size of the right one-way proportional electromagnetic directional valve to discharge or charge oil to the bearing cavity until the pressure of the bearing cavity is adjusted to a target pressure value; and after the pressure of the bearing cavity is adjusted, closing the right one-way proportional electromagnetic directional valve, and discharging or charging oil to the non-bearing cavity by controlling the direction of the two-way electromagnetic directional valve and the opening size of the left one-way proportional electromagnetic directional valve until the pressure of the non-bearing cavity is also adjusted to a target pressure value.

Has the advantages that:

1. the pressure-displacement integrated control system can perform position control and coordinate control on the pressure of the bearing cavity, avoids the influence of the pressure change of the bearing cavity on position adjustment and position mutation at a vertical position, greatly improves the stability, accuracy and response speed of the control of the rocker arm suspension, improves the passing capacity of a vehicle on a bad road surface, and provides a foundation for the realization of obstacle crossing of a whole vehicle platform and active control of the suspension;

secondly, when the state of the rocker arm suspension is in the direction of reducing the static load pressure of the bearing cavity, the pressure of the bearing cavity and the pressure of the non-bearing cavity are finally adjusted to a target pressure value, so that vibration reduction can be realized, and the running stability of the whole vehicle is ensured.

2. The load feedback loop can adjust the hydraulic oil output to each branch rocker arm suspension according to the change of the maximum external load during working, simultaneously ensures that the flow is only related to the opening size of each valve in the pressure-displacement control loop, eliminates the mutual influence among the branches and ensures that each branch realizes synchronous control.

Drawings

FIG. 1(a) is a state diagram of forward swing of the rocker arm, and FIG. 1(b) is a state diagram of backward swing of the rocker arm;

FIG. 2 is a force diagram of a rocker arm suspension;

FIG. 3 is a schematic diagram of a pressure-displacement integrated control system based on a rocker arm suspension;

FIG. 4 is a diagram of a pressure-displacement integrated control process based on a rocker arm suspension according to an embodiment;

FIG. 5 is a diagram illustrating a pressure-displacement integrated control process based on the rocker arm suspension according to the second embodiment;

FIG. 6 is a pressure-displacement integrated control process diagram of a rocker arm suspension according to the third embodiment;

FIG. 7 is a flow chart of a pressure-displacement integrated control method based on a rocker arm suspension;

FIG. 8 is a flow chart of step B of the pressure-displacement integrated control method based on the rocker arm suspension;

FIG. 9 is a flow chart of a pressure-displacement integrated control method step C based on the rocker arm suspension;

the hydraulic control system comprises a hydraulic pump 2, a differential pressure type overflow valve 3, a constant differential pressure reducing valve 4, a bidirectional proportional electromagnetic directional valve 5, a left one-way proportional electromagnetic directional valve 6, a right one-way proportional electromagnetic directional valve 7, a load pressure sensing one-way valve 8, a safety valve 9, a hydraulic system 11, a rocker arm suspension 12, an angular displacement sensor 13, a pressure sensor 14 and a controller 15.

Detailed Description

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

The invention provides a pressure-displacement comprehensive control system based on a rocker arm suspension, and as shown in fig. 3, the control system comprises a rocker arm suspension 12, a hydraulic system 11, an angular displacement sensor 13, a pressure sensor 14 and a controller 15.

The input end of the controller 15 is connected with the angular displacement sensor 13 and the pressure sensor 14, and the output end is connected with the hydraulic system 11; the angular displacement sensor 13 and the pressure sensor 14 are connected with the rocker arm suspension 12; the hydraulic system 11 is connected to a rocker arm suspension 12. The controller 15 acquires the rocker arm position of the rocker arm suspension acquired by the angular displacement sensor 13 and the oil chamber pressure acquired by the pressure sensor 14, so as to judge the state of the rocker arm suspension 12: the pressure sensor is arranged in the static load pressure increasing direction or the static load pressure decreasing direction of the bearing cavity, wherein two pressure sensors are required to be arranged to respectively acquire the pressure of the bearing cavity and the pressure of the non-bearing cavity; the controller 15 controls the hydraulic system 11 to push the rocker arm to rotate and cooperatively regulate the pressure of the bearing cavity according to the state of the rocker arm suspension 12, and the pressure-displacement comprehensive control process is completed.

As shown in fig. 7, in step a, a target position of a rocker arm is set as a target value of position closed-loop control, and a real-time position of each rocker arm of the whole vehicle is acquired to calculate a real-time attitude of the whole vehicle, and a static load pressure value required by each suspension bearing cavity corresponding to the real-time attitude is calculated and used as a target pressure value of pressure closed-loop control; when the required static load pressure value is smaller than a set threshold value, setting the static load pressure value as the set threshold value, wherein the set threshold value is a pressure value which ensures the pushing force and prevents the sudden change of displacement caused by the change of the bearing cavity when crossing the vertical position;

The step B and the step C are not divided into a sequence, and only represent two working conditions.

Step B, when the state of the rocker arm suspension is in the direction of increasing the static load pressure of the bearing cavity (the cantilever rotates clockwise away from the vertical position or rotates anticlockwise away from the vertical position), as shown in FIG. 8, the controller controls the hydraulic system to charge oil to the non-bearing cavity in proportion by taking the received angular displacement and the pressure values of the oil cavity bearing cavity and the non-bearing cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to reach a set target position to complete position closed-loop control; meanwhile, proportional oil drainage is carried out on the bearing cavity by controlling a hydraulic system, the pressure of the bearing cavity is controlled at a target pressure value, and pressure closed-loop control is completed;

step C, when the state of the rocker arm suspension is in a direction of reducing the static load pressure of the bearing cavity (the cantilever rotates anticlockwise close to the vertical position or rotates clockwise close to the vertical position), as shown in FIG. 9, the controller controls the hydraulic system to charge oil to the bearing cavity in proportion by taking the received angular displacement and the pressure values of the bearing cavity and the non-bearing cavity of the oil cavity as feedback values, and pushes the rocker arm to rotate clockwise or anticlockwise to a set target position to perform position closed-loop control; meanwhile, the hydraulic system is controlled to discharge oil to the non-bearing cavity in proportion, and the pressure of the non-bearing cavity is controlled at a set threshold value; after the rocker arm reaches a set target position, the controller controls the hydraulic system to independently perform proportional oil charging or discharging on the bearing cavity and the non-bearing cavity, the pressure of the bearing cavity and the pressure of the non-bearing cavity are adjusted to a target pressure value, and pressure closed-loop control is completed.

The hydraulic system 11 mainly consists of a hydraulic pump 2, a pressure-displacement control loop and a load feedback loop;

the pressure-displacement control loop mainly comprises a bidirectional electromagnetic directional valve 5, a left one-way proportional electromagnetic directional valve 6 and a right one-way proportional electromagnetic directional valve 7; four oil ports of a bidirectional electromagnetic directional valve 5 in a pressure-displacement control loop of a hydraulic system 11 are respectively connected with an oil inlet of a right one-way proportional electromagnetic directional valve 7, an oil inlet of a left one-way proportional electromagnetic directional valve 6, an oil outlet of a fixed-differential pressure reducing valve 4 and an oil tank; the oil outlet of the left one-way proportional electromagnetic directional valve 6 is connected with an A, D oil chamber of the rocker arm suspension 12; an oil outlet of the right one-way proportional electromagnetic directional valve 7 is connected with an B, C oil chamber of the rocker arm suspension 12; the circuit can realize the switching of oil charging and oil discharging of each cavity of the rocker arm suspension, and complete the direction switching of the position adjustment of the rocker arm and the adjustment of the pressure of each cavity.

The load feedback loop mainly comprises a differential pressure type overflow valve 3, a constant differential pressure reducing valve 4, a load pressure sensing shuttle valve 8 and a safety valve 9; an oil inlet of a differential pressure type overflow valve 3 in a load feedback loop of a hydraulic system 11 is connected with an oil outlet of a hydraulic pump 2, an oil outlet of the differential pressure type overflow valve 3 is connected with an oil inlet of a constant differential pressure reducing valve 4 and an oil tank, and a control oil way of the differential pressure type overflow valve 3 is connected with a control oil way of the constant differential pressure reducing valve 4; three oil ports of the load pressure sensing shuttle valve 8 are respectively connected with a control oil port of the fixed differential pressure reducing valve 4, an oil outlet of the left one-way proportional electromagnetic directional valve 6 and an oil outlet of the right one-way proportional electromagnetic directional valve 7; the circuit can adjust the hydraulic oil output to each branch rocker arm suspension 11 according to the change of the maximum external load during working, simultaneously ensures that the flow is only related to the opening size of each valve in the pressure-displacement control circuit, eliminates the mutual influence among the branches and ensures that each branch realizes synchronous control.

When the bidirectional electromagnetic directional valve 5 is electrified and opened to the left position and the left one-way proportional electromagnetic directional valve 6 is electrified and opened, the A, D cavity of the rocker arm suspension 12 is filled with oil, and the oil filling speed is controlled by the electrified current of the left one-way proportional electromagnetic directional valve 6; when the bidirectional electromagnetic directional valve 5 is electrified and opened to the left position and the right one-way proportional electromagnetic directional valve 7 is opened, the B, C cavity of the rocker arm suspension 12 is drained, and the oil drainage speed is controlled by the electrified current of the right one-way proportional electromagnetic directional valve 7.

When the bidirectional electromagnetic directional valve 5 is electrified and opened to the right position and the right one-way proportional electromagnetic directional valve 7 is electrified and opened, the B, C cavity of the rocker arm suspension 12 is filled with oil, and the oil filling speed is controlled by the electrified current of the right one-way proportional electromagnetic directional valve 7; when the bidirectional electromagnetic directional valve 5 is electrified and is turned to the right position and the left one-way proportional electromagnetic directional valve 6 is opened, the A, D cavity of the rocker arm suspension 12 is drained, and the oil drainage speed is controlled by the electrified current of the left one-way proportional electromagnetic directional valve 6.

In the working process, the load pressure sensing shuttle valve 8 feeds the maximum load pressure of all the branch arms of the rocker arm suspension 12 of the whole vehicle back to the differential pressure type overflow valve 3 through a control oil way, the flow returned to the oil tank is regulated by the change of the size of a throttling port of the differential pressure type overflow valve 3, the flow entering each branch arm of the rocker arm suspension 12 is ensured to change along with the change of the load size, and the energy consumption is reduced; meanwhile, the change of the throttle orifice of the fixed-differential pressure reducing valve 4 plays a role of pressure compensation (series pressure compensation) on the oil inlet of the pressure-displacement control loop, so that the pressure difference of the inlet and the outlet of the pressure-displacement control loop is basically kept unchanged, and the flow entering the rocker arm suspension 12 is only related to the sizes of the valve ports of the bidirectional electromagnetic directional valve 5, the left one-way proportional electromagnetic directional valve 6 and the right one-way proportional electromagnetic directional valve 7.

The specific control and adjustment process is implemented as shown in fig. 4, 5 and 6, wherein (r) and (r) are continuous adjustment processes. When the position of the rocker arm is adjusted, if the initial state is shown as a in fig. 4, the bearing cavity of the rocker arm suspension is A, D, and the non-bearing cavity is B, C, wherein firstly, the adjustment process is that the position of the rocker arm suspension rotates clockwise towards the direction of reducing the static load pressure of the bearing cavity, the controller turns the two-way electromagnetic directional valve 5 to the left, controls the size of the valve port of the left one-way proportional electromagnetic directional valve 6 to perform proportional oil filling on the bearing cavity A, D, pushes the rocker arm to rotate clockwise towards the target position, and performs position closed-loop control; meanwhile, in the position closed-loop control process, the pressure of the non-bearing cavity B, C is increased due to the compression of the piston, proportional oil drainage is carried out on the non-bearing cavity B, C by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve 7, the pressure of the non-bearing cavity is controlled at a set threshold value, the threshold value is set to be 2MPa in the embodiment, on one hand, enough driving force is ensured in the rocker arm adjusting process, and on the other hand, the phenomenon that the rocker arm displaces due to the sudden change of the bearing cavity when the rocker arm is close; after the rocker arm reaches the target position, taking the static load pressure required by the calculated corresponding suspension bearing cavity A, D under the vehicle posture as a target pressure value (if the calculated value is less than 2MPa, the static load pressure is set as 2MPa), closing the right one-way proportional electromagnetic directional valve 7, and controlling the direction of the two-way electromagnetic directional valve 5 and the opening size of the left one-way proportional electromagnetic directional valve 6 to drain or fill oil into the bearing cavity A, D until the pressure of the bearing cavity is adjusted to the target pressure value; after the pressure of the bearing cavity is adjusted, the left one-way proportional electromagnetic directional valve 6 is closed, the oil is drained or filled into the non-bearing cavity B, C by controlling the direction of the two-way electromagnetic directional valve 5 and the opening size of the right one-way proportional electromagnetic directional valve 7 until the pressure of the non-bearing cavity is adjusted to a target pressure value, and finally pressure closed-loop control is completed.

The adjustment process is that the position of the rocker arm suspension rotates clockwise towards the static load pressure increasing direction of the bearing cavity, the bearing cavity is changed into B, C after the rocker arm crosses the vertical state, the non-bearing cavity is changed into A, D, at the moment, the controller turns the two-way electromagnetic directional valve 5 to the left position and controls the size of the valve port of the left one-way proportional electromagnetic directional valve 6 to perform proportional oil filling on the non-bearing cavity A, D, and the rocker arm rotates clockwise to reach the target position to complete position closed-loop control; meanwhile, in the process of position closed-loop control, because the pressure of the piston compression bearing cavity B, C rises, proportional oil drainage is carried out on the bearing cavity B, C by controlling the size of the valve port of the right one-way proportional electromagnetic directional valve 7, the pressure of the bearing cavity is controlled by taking the static load pressure of the suspension bearing cavity B, C calculated by the corresponding vehicle posture as a target pressure value, and pressure closed-loop control is completed.