AGV differential steering wheel hydraulic suspension control system

Abstract

The utility model discloses a kind of AGV differential rudder wheel hydraulic suspension control systems, including oil tank, constant pressure variable hydraulic pump, system pressure sensor, slide valve type solenoid valve, two-position four-way solenoid valve, overflow valve, base plate and four sets of parallelly arranged hydraulic execution unit on base plate, each set of hydraulic execution unit includes electro-hydraulic proportional servo valve, double check solenoid valve, oil inlet cavity end pressure sensor, oil return cavity end pressure sensor, energy accumulator, hydraulic rotary joint, hydraulic cylinder and several hydraulic pipelines;The control system solves the problem that AGV differential wheel group driving wheel and ground have not enough adhesion, effectively solves the problem that AGV differential rudder wheel is caused by ground unevenness Driving wheel group skidding problem, so that AGV has omni-directional, full ground adaptability.

Description

Technical Field

[0001] This utility model relates to the field of AGV control equipment technology, and in particular to an AGV differential steering wheel hydraulic suspension control system. Background Technology

[0002] In recent years, my country's manufacturing industry has developed rapidly, and manufacturing production has gradually become automated. To meet the demands of automated and intelligent production, as well as space-efficient production, manufacturing enterprises are placing increasingly higher demands on flexible production and distribution. The handling of extra-long, extra-wide, and heavy-duty workpieces has long been a challenge for manufacturing companies. Traditionally, overhead cranes and RGVs have been used in combination to transfer heavy-duty workpieces, involving multiple transfer steps. The more transfer steps involved, the higher the potential risks and the lower the production efficiency.

[0003] AGVs are now widely used as flexible conveying equipment in manufacturing processes. However, in the production of heavy workpieces, the flatness of the ground often fails to meet the requirements of conventional AGVs for ground travel. Large undulations and uneven ground can easily cause the AGV drive wheels to slip. To meet the requirements of automated transfer of ultra-long, ultra-wide, and heavy-duty workpieces and to ensure the adaptability of the AGV drive wheels to the ground, this invention proposes an AGV differential steering wheel hydraulic suspension control system. This system solves the problem of sufficient adhesion between the AGV differential steering wheel drive wheels and the ground, effectively resolving the slippage problem caused by uneven ground, and giving the AGV omnidirectional, all-terrain adaptability. Utility Model Content

[0004] The purpose of this invention is to address the above-mentioned issues by providing an AGV differential steering wheel hydraulic suspension control system. This control system solves the problem of insufficient adhesion between the AGV differential wheel drive wheel and the ground, effectively resolving the slippage problem of the AGV differential steering wheel drive wheel caused by uneven ground, thus enabling the AGV to have omnidirectional and all-terrain adaptability.

[0005] The specific solution of this utility model is: an AGV differential steering wheel hydraulic suspension control system, including an oil tank, a constant pressure variable hydraulic pump, a system pressure sensor, a spool valve type solenoid valve, a two-position four-way solenoid valve, an overflow valve, a base plate, and four sets of hydraulic actuators connected in parallel on the base plate. Each hydraulic actuator includes an electro-hydraulic proportional servo valve, a double check valve, an inlet pressure sensor, a return pressure sensor, an accumulator, a hydraulic rotary joint, a hydraulic cylinder, and several hydraulic pipelines; the constant pressure variable hydraulic pump is connected to the oil tank via hydraulic pipelines; the spool valve type solenoid valve and the system pressure sensor are connected to the constant pressure variable hydraulic pump via hydraulic pipelines; the spool valve type solenoid valve and the system pressure sensor are connected to the constant pressure variable hydraulic pump via hydraulic pipelines; the spool valve type solenoid valve and the system pressure sensor are connected to the constant pressure variable hydraulic pump via hydraulic pipelines; the spool valve type solenoid valve and the system pressure sensor are connected to the system pressure sensor. A bypass system consisting of a two-position four-way solenoid valve and a relief valve is connected via hydraulic lines; a constant-pressure variable hydraulic pump is connected to the base plate via hydraulic lines; the base plate is connected to the electro-hydraulic proportional servo valve via hydraulic lines; ports A and B of the electro-hydraulic proportional servo valve are respectively connected to double check valves via hydraulic lines; the double check valves are connected to the hydraulic rotary joint on the hydraulic cylinder via hydraulic lines; pressure sensors at the inlet and return ends of the hydraulic cylinder are connected in parallel to the hydraulic lines at the inlet and return ends of the hydraulic cylinder, respectively; the accumulator is connected in parallel to port P of the electro-hydraulic proportional servo valve via hydraulic lines; a multi-hydraulic suspension hydraulic cylinder control system is also provided, which is used for the motion control of the hydraulic cylinders.

[0006] Furthermore, the slide valve type solenoid valve and system pressure sensor described in this utility model are connected to a constant pressure variable hydraulic pump via hydraulic pipes. According to the pressure value set by the system pressure sensor, the constant pressure variable hydraulic pump automatically adjusts the output pressure and flow rate.

[0007] Furthermore, the two-position four-way solenoid valve and relief valve described in this utility model are also connected to a constant-pressure variable hydraulic pump via a cartridge valve; the two-position four-way solenoid valve and relief valve are used together, and by controlling the two-position four-way solenoid valve, the system pressure of the hydraulic circuit can be controlled and regulated. When the pumping pressure of the constant-pressure variable hydraulic pump exceeds the system set pressure value, the excess hydraulic oil flows back to the oil tank through the relief valve; the two-position four-way solenoid valve is normally closed by default, which can ensure that the hydraulic circuit system is within the set pressure range. When the two-position four-way solenoid valve is energized, it can allow the hydraulic circuit system to quickly depressurize.

[0008] Furthermore, the electro-hydraulic proportional servo valve described in this utility model is connected to a constant-pressure variable hydraulic pump via a base plate. Based on the analog electrical signal fed back by the position sensor built into the hydraulic cylinder, it can quickly respond and automatically adjust the flow and pressure in the input and output hydraulic cylinder pipeline system, thereby controlling the lifting speed of the hydraulic cylinder. The multi-hydraulic suspension hydraulic cylinder control system meets the requirements for the lifting synchronization of multiple hydraulic cylinders based on the position control loop of the electro-hydraulic proportional servo valve at the front end of each hydraulic cylinder, ensuring synchronization accuracy.

[0009] Furthermore, in this utility model, the A port and B port of the electro-hydraulic proportional servo valve in each hydraulic actuator unit are respectively connected to the corresponding double check valve via hydraulic pipelines; the double check valve is connected to the hydraulic rotary joint on the hydraulic cylinder via hydraulic pipelines; the double check valve can prevent hydraulic oil backflow and ensure the normal operation of the pipeline system.

[0010] Furthermore, in this invention, the pressure sensor at the inlet end and the pressure sensor at the return end are connected in parallel to the hydraulic lines at the inlet end and the return end of the hydraulic cylinder, respectively; the accumulator is connected in parallel to the P port of the electro-hydraulic proportional servo valve via a hydraulic line; after feedback and comparison of the analog electrical signals from the pressure sensors at the inlet end and the return end of each hydraulic cylinder, the accumulator automatically compensates for the pressure of the pipeline system at the inlet end of the hydraulic cylinder, thereby ensuring that the hydraulic output pressure is always within the preset value range.

[0011] This utility model has the following advantages:

[0012] 1. This utility model employs a constant-pressure variable-displacement hydraulic pump connected to an oil tank. A spool-type solenoid valve and a system pressure sensor are connected to the constant-pressure variable-displacement hydraulic pump via hydraulic pipes. Based on the pressure value set by the system pressure sensor, it can not only automatically adjust the output pressure and flow rate according to the working load, thereby improving the system's energy utilization rate, but also quickly adjust its output pressure and flow rate when the load changes, rapidly adapting to changes in system operating conditions.

[0013] 2. In this utility model, the two-position four-way solenoid valve and the relief valve are connected to the constant-pressure variable hydraulic pump via a cartridge valve. The two-position four-way solenoid valve and the relief valve work together. By controlling the two-position four-way solenoid valve, the system pressure of the hydraulic circuit can be easily controlled and adjusted. When the pumping pressure of the constant-pressure variable hydraulic pump exceeds the system's set pressure value, the excess hydraulic oil flows back to the oil tank through the relief valve. Furthermore, the two-position four-way solenoid valve is normally closed by default, ensuring that the hydraulic circuit system remains within the set pressure range, thus maintaining pressure. When the two-position four-way solenoid valve is energized, it allows for rapid pressure relief of the hydraulic circuit system, achieving energy saving and emission reduction.

[0014] 3. In this utility model, the electro-hydraulic proportional servo valve is connected to a constant-pressure variable hydraulic pump via a base plate. Based on the analog electrical signal fed back by the position sensor built into the hydraulic cylinder, it can quickly respond and automatically adjust the flow and pressure in the input and output hydraulic cylinder pipeline system, thereby controlling the lifting speed of the hydraulic cylinder. For a multi-hydraulic suspension hydraulic cylinder control system, the system meets the requirements for the synchronous lifting of multiple hydraulic cylinders based on the position control loop of the electro-hydraulic proportional servo valve at the front end of each hydraulic cylinder, ensuring more precise synchronization accuracy.

[0015] 4. In this utility model, the A and B ports of the electro-hydraulic proportional servo valve are respectively connected to a double check valve via hydraulic lines; the double check valve is connected to a hydraulic rotary joint on the hydraulic cylinder via hydraulic lines. The double check valve can effectively prevent hydraulic oil backflow and ensure the normal operation of the pipeline system.

[0016] 5. In this utility model, the pressure sensor at the inlet and return oil chambers of the hydraulic cylinder are connected in parallel to the hydraulic lines at the inlet and return oil chambers of the hydraulic cylinder, respectively; the accumulator is connected in parallel to the P port of the electro-hydraulic proportional servo valve via a hydraulic line. After feedback and comparison of the analog electrical signals from the pressure sensors at the inlet and return oil chambers of each hydraulic cylinder, the accumulator can automatically compensate for the pressure in the pipeline system at the inlet oil chamber of the hydraulic cylinder, thereby ensuring that the hydraulic output pressure is always within the preset range, and ensuring that the AGV differential steering wheel drive wheel set has sufficient adhesion to the ground to prevent slippage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the hydraulic principle of this utility model.

[0018] In the diagram: 1-oil tank, 2-constant pressure variable hydraulic pump, 3-system pressure sensor, 4-spool valve type solenoid valve, 5-two-position four-way solenoid valve, 6-relief valve, 7-base plate, 8-electro-hydraulic proportional servo valve, 9-double check valve type solenoid valve, 10-inlet pressure sensor, 11-return pressure sensor, 12-accumulator, 13-hydraulic rotary joint, 14-hydraulic cylinder. Detailed Implementation

[0019] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0020] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] See Figure 1This utility model relates to a hydraulic suspension control system for an AGV differential steering wheel, comprising an oil tank, a constant-pressure variable-displacement hydraulic pump, a system pressure sensor, a spool-type solenoid valve, a two-position four-way solenoid valve, a relief valve, a base plate, and four sets of hydraulic actuators connected in parallel on the base plate. Each hydraulic actuator includes an electro-hydraulic proportional servo valve, a double check valve, an inlet pressure sensor, a return pressure sensor, an accumulator, a hydraulic rotary joint, a hydraulic cylinder, and several hydraulic lines. The constant-pressure variable-displacement hydraulic pump is connected to the oil tank via hydraulic lines. The spool-type solenoid valve and the system pressure sensor are connected to the constant-pressure variable-displacement hydraulic pump via hydraulic lines. The spool-type solenoid valve and the two-position four-way solenoid valve... A bypass system consisting of a four-way solenoid valve and a relief valve is connected via hydraulic lines; a constant-pressure variable-displacement hydraulic pump is connected to a base plate via hydraulic lines; the base plate is connected to an electro-hydraulic proportional servo valve via hydraulic lines; ports A and B of the electro-hydraulic proportional servo valve are respectively connected to double check-return solenoid valves via hydraulic lines; the double check-return solenoid valves are connected to a hydraulic rotary joint on the hydraulic cylinder via hydraulic lines; pressure sensors at the inlet and return ends of the hydraulic cylinder are connected in parallel on the hydraulic lines at the inlet and return ends of the hydraulic cylinder, respectively; the accumulator is connected in parallel to port P of the electro-hydraulic proportional servo valve via hydraulic lines; a multi-hydraulic suspension hydraulic cylinder control system is also provided, which is used for the motion control of the hydraulic cylinders. Furthermore, the spool-type solenoid valve and system pressure sensor described in this invention are connected to the constant-pressure variable-displacement hydraulic pump via hydraulic lines, and the constant-pressure variable-displacement hydraulic pump automatically adjusts its output pressure and flow rate according to the pressure value set by the system pressure sensor. Furthermore, the two-position four-way solenoid valve and relief valve described in this invention are also connected to a constant-pressure variable hydraulic pump via a cartridge valve. The two-position four-way solenoid valve and relief valve work together; by controlling the two-position four-way solenoid valve, the system pressure of the hydraulic circuit can be controlled and adjusted. When the pumping pressure of the constant-pressure variable hydraulic pump exceeds the system's set pressure value, the excess hydraulic oil flows back to the oil tank through the relief valve. The two-position four-way solenoid valve operates in a normally closed state by default, ensuring that the hydraulic circuit system remains within the set pressure range. When the two-position four-way solenoid valve is energized, it allows for rapid pressure relief of the hydraulic circuit system. Furthermore, the electro-hydraulic proportional servo valve described in this invention is connected to the constant-pressure variable hydraulic pump via a base plate. Based on the analog electrical signal fed back by the position sensor built into the hydraulic cylinder, it can quickly respond and automatically adjust the flow and pressure in the input and output hydraulic cylinder pipeline system, thereby controlling the lifting speed of the hydraulic cylinder. The multi-hydraulic suspension hydraulic cylinder control system, based on the position control loop of the electro-hydraulic proportional servo valve at the front end of each hydraulic cylinder, meets the requirements for the synchronous lifting of multiple hydraulic cylinders, ensuring synchronization accuracy. Furthermore, in this utility model, the A port and B port of the electro-hydraulic proportional servo valve in each hydraulic actuator unit are respectively connected to the corresponding double check valve via hydraulic pipelines; the double check valve is connected to the hydraulic rotary joint on the hydraulic cylinder via hydraulic pipelines; the double check valve can prevent hydraulic oil backflow and ensure the normal operation of the pipeline system.Furthermore, in this invention, the pressure sensor at the inlet end and the pressure sensor at the return end are connected in parallel to the hydraulic lines at the inlet end and the return end of the hydraulic cylinder, respectively; the accumulator is connected in parallel to the P port of the electro-hydraulic proportional servo valve via a hydraulic line; after feedback and comparison of the analog electrical signals from the pressure sensors at the inlet end and the return end of each hydraulic cylinder, the accumulator automatically compensates for the pressure of the pipeline system at the inlet end of the hydraulic cylinder, thereby ensuring that the hydraulic output pressure is always within the preset value range.

[0022] The connection and usage of this utility model will be described in detail below with reference to the accompanying drawings.

[0023] This utility model relates to an AGV differential steering wheel hydraulic suspension control system, such as... Figure 1 As shown, it includes: oil tank 1, constant pressure variable hydraulic pump 2, system pressure sensor 3, spool valve type solenoid valve 4, two-position four-way solenoid valve 5, relief valve 6, base plate 7, electro-hydraulic proportional servo valve 8, double check valve type solenoid valve 9, inlet chamber pressure sensor 10, return chamber pressure sensor 11, accumulator 12, hydraulic rotary joint 13, and hydraulic cylinder 14. The constant pressure variable hydraulic pump 2 is connected to the oil tank 1 via hydraulic pipes; the spool valve type solenoid valve 4 and the system pressure sensor 3 are connected to the constant pressure variable hydraulic pump 2 via hydraulic pipes; the spool valve type solenoid valve 4 is connected to the bypass system (two-position four-way solenoid valve 5 and relief valve 6) via hydraulic pipes; the constant pressure variable hydraulic pump 2 is connected to the base plate 7 via hydraulic pipes; the base plate 7 is connected to the electro-hydraulic proportional servo valve 8 via hydraulic pipes; the A port and B port of the electro-hydraulic proportional servo valve 8 are respectively connected to the double check valve 9 via hydraulic pipes; the double check valve 9 is connected to the hydraulic rotary joint 13 on the hydraulic cylinder 14 via hydraulic pipes; the inlet pressure sensor 10 and the return pressure sensor 11 are respectively connected in parallel on the hydraulic pipes of the inlet and return ends of the hydraulic cylinder 14; the accumulator 12 is connected in parallel to the P port of the electro-hydraulic proportional servo valve 8 via hydraulic pipes.

[0024] This invention utilizes a hydraulic control circuit to ensure sufficient adhesion between the AGV differential wheel drive wheel and the ground, effectively solving the problem of AGV differential steering wheel slippage caused by uneven ground, thus enabling the AGV to have omnidirectional and all-terrain adaptability.

[0025] A constant-pressure variable-displacement hydraulic pump is connected to the oil tank. A spool-type solenoid valve and a system pressure sensor are connected to the constant-pressure variable-displacement hydraulic pump via hydraulic pipes. Based on the pressure value set by the system pressure sensor, the output pressure and flow rate can be automatically adjusted according to the workload, thereby improving the system's energy utilization rate. Furthermore, when the load changes, the output pressure and flow rate can be quickly adjusted to adapt to changes in system operating conditions. In this invention, a two-position four-way solenoid valve and a relief valve are connected to the constant-pressure variable-displacement hydraulic pump via cartridge valves. The two-position four-way solenoid valve and the relief valve work together. By controlling the two-position four-way solenoid valve, the system pressure of the hydraulic circuit can be easily controlled and adjusted. When the pumping pressure of the constant-pressure variable-displacement hydraulic pump exceeds the system's set pressure value, the excess hydraulic oil flows back to the oil tank through the relief valve. Furthermore, the two-position four-way solenoid valve is normally closed by default, ensuring that the hydraulic circuit system maintains pressure within the set pressure range. When the two-position four-way solenoid valve is energized, it allows for rapid pressure release in the hydraulic circuit system, contributing to energy conservation and emission reduction. In this invention, the electro-hydraulic proportional servo valve is connected to a constant-pressure variable hydraulic pump via a base plate. Based on the analog electrical signal fed back by the position sensor built into the hydraulic cylinder, it can quickly respond and automatically adjust the flow and pressure in the input and output hydraulic cylinder pipeline system, thereby controlling the lifting and lowering speed of the hydraulic cylinder. For the multi-hydraulic suspension hydraulic cylinder control system, the system meets the requirements for the synchronous lifting and lowering of multiple hydraulic cylinders based on the position control loop of the electro-hydraulic proportional servo valve at the front end of each hydraulic cylinder, ensuring more precise synchronization accuracy. In this invention, the A and B ports of the electro-hydraulic proportional servo valve are connected to double check valves via hydraulic pipelines. The double check valves are connected to the hydraulic rotary joints on the hydraulic cylinders via hydraulic pipelines. The double check valve effectively prevents hydraulic oil backflow, ensuring the normal operation of the pipeline system. In this invention, the inlet pressure sensor and return pressure sensor are connected in parallel to the hydraulic lines at the inlet and return ends of the hydraulic cylinder, respectively. The accumulator is connected in parallel to the P port of the electro-hydraulic proportional servo valve via a hydraulic line. Through feedback and comparison of the analog electrical signals from the inlet and return pressure sensors of each hydraulic cylinder, the accumulator automatically compensates for the pressure in the pipeline system at the inlet end of the hydraulic cylinder, thereby ensuring that the hydraulic output pressure remains within the preset range and that the AGV differential steering wheel drive wheel assembly has sufficient traction on the ground to prevent slippage.

Claims

1. A hydraulic suspension control system for an AGV differential steering wheel, characterized in that: The system includes an oil tank, a constant-pressure variable-displacement hydraulic pump, a system pressure sensor, a spool-type solenoid valve, a two-position four-way solenoid valve, a relief valve, a base plate, and four sets of hydraulic actuators connected in parallel on the base plate. Each hydraulic actuator includes an electro-hydraulic proportional servo valve, a double check valve, an inlet pressure sensor, a return pressure sensor, an accumulator, a hydraulic rotary joint, a hydraulic cylinder, and several hydraulic lines. The constant-pressure variable-displacement hydraulic pump is connected to the oil tank via hydraulic lines. The spool-type solenoid valve and the system pressure sensor are connected to the constant-pressure variable-displacement hydraulic pump via hydraulic lines. The spool-type solenoid valve and the two-position four-way solenoid valve and the relief valve form a... The bypass system is connected via hydraulic lines; the constant pressure variable hydraulic pump is connected to the base plate via hydraulic lines; the base plate is connected to the electro-hydraulic proportional servo valve via hydraulic lines; ports A and B of the electro-hydraulic proportional servo valve are connected to double check valves via hydraulic lines; the double check valves are connected to the hydraulic rotary joint on the hydraulic cylinder via hydraulic lines; the pressure sensor at the inlet end and the pressure sensor at the return end are connected in parallel to the hydraulic lines at the inlet end and the return end of the hydraulic cylinder, respectively; the accumulator is connected in parallel to port P of the electro-hydraulic proportional servo valve via hydraulic lines; a multi-hydraulic suspension hydraulic cylinder control system is also provided, which is used for the motion control of the hydraulic cylinders.

2. The AGV differential steering wheel hydraulic suspension control system according to claim 1, characterized in that: The slide valve type solenoid valve and the system pressure sensor are connected to the constant pressure variable hydraulic pump via hydraulic pipes. According to the pressure value set by the system pressure sensor, the constant pressure variable hydraulic pump automatically adjusts the output pressure and flow rate.

3. The AGV differential steering wheel hydraulic suspension control system according to claim 1, characterized in that: The two-position four-way solenoid valve and relief valve are also connected to the constant pressure variable hydraulic pump via a cartridge valve. The two-position four-way solenoid valve and relief valve are used together. By controlling the two-position four-way solenoid valve, the system pressure of the hydraulic circuit can be controlled and regulated. When the pumping pressure of the constant pressure variable hydraulic pump exceeds the system set pressure value, the excess hydraulic oil flows back to the oil tank through the relief valve. The two-position four-way solenoid valve is normally closed by default, which can ensure that the hydraulic circuit system is within the set pressure range. When the two-position four-way solenoid valve is energized, it can allow the hydraulic circuit system to depressurize quickly.

4. The AGV differential steering wheel hydraulic suspension control system according to claim 1, characterized in that: The electro-hydraulic proportional servo valve is connected to the constant pressure variable hydraulic pump via the base plate. Based on the analog electrical signal fed back by the position sensor built into the hydraulic cylinder, it can quickly respond and automatically adjust the flow and pressure in the input and output hydraulic cylinder pipeline system, thereby controlling the lifting speed of the hydraulic cylinder. The multi-hydraulic suspension hydraulic cylinder control system meets the requirements of the lifting synchronization of multiple hydraulic cylinders and ensures synchronization accuracy by using the position control loop of the electro-hydraulic proportional servo valve at the front end of each hydraulic cylinder.

5. The AGV differential steering wheel hydraulic suspension control system according to claim 1, characterized in that: In each hydraulic actuator unit, the A and B ports of the electro-hydraulic proportional servo valve are connected to corresponding double check valves via hydraulic pipelines. The double check valves are connected to the hydraulic rotary joints on the hydraulic cylinders via hydraulic pipelines. The double check valves can prevent hydraulic oil backflow and ensure the normal operation of the pipeline system.

6. The AGV differential steering wheel hydraulic suspension control system according to claim 1, characterized in that: The pressure sensor at the inlet and return oil chambers are connected in parallel to the hydraulic lines at the inlet and return oil chambers of the hydraulic cylinder, respectively. The accumulator is connected in parallel to the P port of the electro-hydraulic proportional servo valve via a hydraulic line. After feedback and comparison of the analog electrical signals from the pressure sensors at the inlet and return oil chambers of each hydraulic cylinder, the accumulator automatically compensates for the pressure in the pipeline system at the inlet oil chamber of the hydraulic cylinder, thereby ensuring that the hydraulic output pressure is always within the preset range.

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