Dual spool can bus control unit and control method

Abstract

The application relates to a double-valve-core CAN bus control unit which comprises a control end cover and an end cover plate, the control end cover is sealingly installed with the end cover plate, an electro-hydraulic proportional pilot valve assembly and a displacement sensor assembly are integrated on the control end cover, an oil inlet channel and an oil return channel are arranged on the control end cover, a control panel and a connector are arranged on the control end cover, and the displacement sensor assembly is signal-connected to the control panel. The control method can realize multi-mode control, and the control mode is judged according to the working condition in the adaptive control mode; in the manual setting control mode, the displacement closed-loop control mode, the flow closed-loop control mode or the pressure closed-loop control mode can be set. The control unit is used in match with a main valve as an independent electric control unit, the control precision is higher, the control method is more flexible, and the volume is smaller; the main valve core position can be accurately controlled in each control mode, the main valve core can quickly and accurately reach the preset position, and the responsiveness and stability of the main valve are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology for engineering machinery, and in particular to a dual-valve CAN bus control unit and control method. Background Technology

[0002] As a key hydraulic component in construction machinery, electro-hydraulic valves are also evolving towards digitalization and intelligence with the increasing automation and intelligence of construction machinery. Simultaneously, with the rapid development of computer information technology and network communication technology, the digitalization, intelligence, and integration of hydraulic components and complete machine systems have become an inevitable trend. Digital hydraulic products such as digitally controlled electro-hydraulic valves and electro-proportional control variable pumps based on CAN bus and DSP are gradually appearing on the market.

[0003] Traditional dual-valve electro-hydraulic proportional controllers use an external independent controller to output specific voltage or current signals to control the controlled object. Control of dual-valve electro-hydraulic valves is primarily open-loop control, resulting in poor performance. With controller development, constant current drives have gradually emerged, suppressing the influence of load impedance thermal characteristics and enabling closed-loop control with better performance. In the 1970s and 80s, control methods developed into analog and on / off modes. Analog control, based on power amplifiers operating in the linear amplification region, suffers from high power consumption, high temperature rise, and low energy utilization. On / off control primarily uses pulse width modulation (PWM), controlling the controlled object through digital signals output by the controller. PWM-based controllers offer advantages such as flexible control and high efficiency. As the requirements for controlled objects become increasingly demanding, electro-hydraulic valve controllers are evolving towards intelligence and integration. While some CAN bus control units have been successfully developed abroad, domestic CAN bus control units are still immature. There is a huge market demand for low-power, stable, and reliable CAN bus control units. Therefore, developing CAN bus control units is of great significance, promoting the upgrading of proportional controller products and providing important evidence for the intelligent and automated implementation of core hydraulic components.

[0004] Traditional dual-spool electro-hydraulic valves consist of a main valve body and end caps. The main valve body houses the main valve spool, a replenishing valve, and other auxiliary components, while the end cap contains an electro-hydraulic proportional pilot valve. The entire valve system controls the pilot valve spool's reversal via a control signal output from an external controller, thereby controlling the movement of the main valve spool. The movement of the main valve spool is entirely dependent on the external controller's command signals. Since the valve body and end caps of dual-spool electro-hydraulic valves lack integrated sensors, closed-loop control and load-adaptive control are not possible. Existing traditional dual-spool electro-hydraulic valves rely on an external controller to control the main valve spool's movement. Because the main valve lacks integrated sensors and other sensing elements, it can only achieve open-loop control, resulting in low control accuracy and slow response speed. Traditional electro-hydraulic valves passively receive control commands from the overall controller; they cannot automatically switch control programs based on changes in load conditions, exhibiting low flexibility. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a dual-valve-core CAN bus control unit and control method. This control unit is used as an independent electronic control unit matched with the main valve, resulting in higher control precision, more flexible control methods, and a smaller size. Each control mode can achieve closed-loop precise control of the main valve core position, allowing the main valve core to quickly and accurately reach the preset position, effectively improving the responsiveness and stability of the main valve.

[0006] In a first aspect, the present invention provides a dual-valve CAN bus control unit.

[0007] A dual-valve CAN bus control unit includes a control end cover and an end cover plate. The control end cover and the end cover plate are sealed together. The control end cover has two first mounting holes and two second mounting holes. An electro-hydraulic proportional pilot valve assembly is installed in each of the first mounting holes, and a displacement sensor assembly is installed in each of the second mounting holes. An oil inlet passage and an oil return passage are opened on the control end cover and extend to the first mounting holes. A controller cover plate is provided on the control end cover, and a control board is installed inside the controller cover plate. A connector is provided on the controller cover plate, and the displacement sensor assembly is connected to the control board.

[0008] Optionally, the axes of the two first mounting holes and the two second mounting holes are located in the same plane, and the two first mounting holes are located on both sides of the two second mounting holes.

[0009] Secondly, the present invention provides a dual-valve CAN bus control method.

[0010] A dual-valve CAN bus control method includes a main pump, a flow valve, a directional valve, an actuator cylinder, and the aforementioned dual-valve CAN bus control unit. The main pump supplies oil to two electro-hydraulic proportional pilot valve assemblies. Two working ports of one electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the directional valve, and two working ports of the other electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the flow valve. The two working ports of the directional valve are respectively connected to the large and small chambers of the actuator cylinder. This control method includes:

[0011] Step S1: Set parameters on the host computer;

[0012] Step S2: Set the host computer control mode. If it is the adaptive control mode, then execute steps S3 and S4; if it is the manual control mode, then execute step S5.

[0013] Step S3: Calculate the load value;

[0014] Step S4: Determine whether the load is a tensile load or a resistance load based on the load value in step S3. If it is a tensile load, then execute oil inlet speed control and oil return speed control; if it is a resistance load, then execute oil inlet speed control and oil return pressure control.

[0015] Step S5: Set the control mode of each main valve core to: displacement closed-loop control mode, flow closed-loop control mode, or pressure closed-loop control mode.

[0016] Step S6: Collect data and transmit it to the control board.

[0017] Optionally, when the load value is <0, the current load is a tensile load; when the load value is ≥0, the current load is a resistance load.

[0018] Optionally, one of the two displacement sensor assemblies is used to detect the displacement of the valve core of the flow valve, and the other is used to detect the displacement of the valve core of the reversing valve.

[0019] Optionally, the displacement closed-loop control mode involves performing closed-loop control based on the error between the detected values ​​of the two displacement sensor assemblies and the corresponding actual required displacement values, to obtain a pair of control currents, namely, control current one and control current two, which are used to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies.

[0020] Optionally, the flow closed-loop control mode: based on the error between the real-time flow value of the corresponding valve port and the actual required flow value, closed-loop control is performed to obtain a pair of control currents 1 and 2 applied to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies.

[0021] Optionally, a first integrated temperature and pressure sensor is installed in the oil line entering the large cavity of the actuator cylinder, and a second integrated temperature and pressure sensor is installed in the oil line entering the small cavity of the actuator cylinder.

[0022] Optionally, the pressure closed-loop control mode involves performing closed-loop control based on the error between the pressure values ​​detected by the first integrated temperature and pressure sensor and the second integrated temperature and pressure sensor and the actual required pressure value, to obtain a pair of control currents, namely, control current one and control current two, which are used to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies.

[0023] Optionally, a pressure reducing valve is provided on the oil line supplying oil to the two electro-hydraulic proportional pilot valve assemblies by the main pump, and a compensation valve is provided on the oil line connecting the main pump and the flow valve.

[0024] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0025] 1. This invention designs a dual-valve-core CAN bus electronic control unit, which is used as an independent electronic control unit matched with the main valve. Compared with the original traditional electro-hydraulic valve, the electro-hydraulic valve matched with the CAN bus electronic control unit has higher control accuracy, more flexible control method, and smaller overall valve size.

[0026] 2. The present invention designs a dual-valve-core CAN bus electronic control unit, which integrates an LVDT displacement sensor, enabling closed-loop precise control of the main valve core position, allowing the main valve core to quickly and accurately reach the preset position, thereby improving the responsiveness and stability of the main valve;

[0027] 3. The present invention designs a dual-valve core CAN bus electronic control unit, which integrates a controller and can pre-decode the valve group control program, saving the debugging time of valve group control during the overall machine control.

[0028] 4. The CAN bus electronic control unit of the present invention, combined with the parameters of the hydraulic cylinder of the whole machine and the temperature and pressure sensor signal of the main valve port, can perform load condition calculation, realize the adaptive adjustment of the main valve flow and pressure closed-loop control algorithm, and improve the flexibility of main valve control;

[0029] 5. The CAN bus electronic control unit of the present invention is equipped with host computer application software, which can easily set valve parameters and configure control modes, reducing the requirements for users' professional skills and facilitating its widespread application. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the dual-valve CAN bus control unit of the present invention;

[0031] Figure 2 This is a schematic diagram of the control principle of the dual-valve CAN bus control unit of the present invention;

[0032] Figure 3 This is a flowchart of the dual-valve CAN bus control method of the present invention.

[0033] In the attached diagram: 1-End cover plate, 2-Second mounting hole, 3-Second mounting hole, 4-Sealing ring, 5-Control end cover, 6-Control board, 7-Controller cover plate, 8-Connector, 9-Sealing ring, 10-Tension plug, 11-Tension plug, 12-First mounting hole, 13-Sealing ring, 14-Sealing ring, 15-First mounting hole, 16-Tension plug;

[0034] 4.1-Electro-hydraulic proportional pilot valve assembly; 4.2-Electro-hydraulic proportional pilot valve assembly; 4.3-Pressure reducing valve; 4.4-Main pump; 4.5-Compensation valve; 4.6-Flow valve; 4.7-Displacement sensor assembly; 4.8-Directional control valve; 4.9-Displacement sensor assembly; 4.10-First integrated temperature and pressure sensor; 4.11-Actuating cylinder; 4.12-Second integrated temperature and pressure sensor; 4.13-Host computer. Detailed Implementation

[0035] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention, including various details to aid understanding. These details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description. Example 1

[0036] As attached Figure 1 As shown, the dual-valve CAN bus control unit includes a control end cover 5 and an end cover plate 1. The control end cover 5 and the end cover plate 1 are sealed together and equipped with a sealing ring 4. The control end cover 5 has two first mounting holes 12 / 15 and two second mounting holes 2 / 3. Electro-hydraulic proportional pilot valve assemblies 4.1 / 4.2 are respectively installed in the first mounting holes 12 / 15, and displacement sensor assemblies 4.7 / 4.9 are respectively installed in the second mounting holes 2 / 3. The control end cover 5 has an oil inlet passage and an oil return passage that extend to the first mounting holes 12 / 15. The control end cover 5 is equipped with a controller cover plate 7, and a sealing ring 9 is provided between the control end cover 5 and the controller cover plate 7. The controller cover plate 7 is equipped with a control board 6 and a connector 8 for connecting to an external power supply. The displacement sensor assembly signals are connected to the control board 6. Sealing rings 13 and 14 are respectively provided on the control end cover 5 at the positions corresponding to the two second mounting holes 2 / 3 for sealing during the installation of the main valve.

[0037] In this embodiment, the axes of the two first mounting holes and the two second mounting holes are located in the same plane, with the two first mounting holes situated on either side of the two second mounting holes. Unused oil passages leading to the outside are sealed using expansion plugs, such as... Figure 1 The numbers 10, 11, and 16 represent the upward and downward pressure levels. Example 2

[0038] As attached Figure 2 and 3 As shown, the dual-valve CAN bus control method includes a main pump 4.4, a flow valve 4.6, a directional valve 4.8, an actuator cylinder 4.11, and the dual-valve CAN bus control unit in the above embodiment 1. The main pump 4.4 supplies oil to two electro-hydraulic proportional pilot valve assemblies 4.1 and 4.2. The two working ports of one electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the directional valve 4.8, and the two working ports of the other electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the flow valve 4.6. The two working ports of the directional valve 4.8 are respectively connected to the large and small chambers of the actuator cylinder 4.11. This control method includes:

[0039] Step S1: Set the host computer parameters. In the host computer software, set the basic parameters of the main valve and the sensor value range, etc., to match the CAN bus control unit.

[0040] Step S2: Set the upper computer control mode. If it is the adaptive control mode, the control board calculates the working condition based on the detected sensor information and determines the most suitable control mode under the current state, and then executes steps S3 and S4. If it is the manual control mode, it is assumed that the control mode of each main valve core is set, and then steps S5 are executed.

[0041] Step S3: Calculate the load value;

[0042] Step S4: Determine whether the load is a tensile load or a resistance load based on the load value in step S3. If it is a tensile load, then execute oil inlet speed control and oil return speed control; if it is a resistance load, then execute oil inlet speed control and oil return pressure control.

[0043] Step S5: Set the control mode of each main valve core to: displacement closed-loop control mode, flow closed-loop control mode, or pressure closed-loop control mode.

[0044] Step S6: Collect data and transmit it to the control board.

[0045] The control board calculates the load according to formula (1) based on the pressure sensor signal and the actuator parameters:

[0046] (1)

[0047] Where: F—load force, unit N;

[0048] Ph—pressure in the large chamber of the hydraulic cylinder, in bar;

[0049] Pr—Pressure in the small chamber of the hydraulic cylinder, in bar;

[0050] Ah—Equivalent working area of ​​the large cavity of the hydraulic cylinder, in mm. 2 ;

[0051] Ar—Equivalent working area of ​​the small cavity in the hydraulic cylinder, mm 2 ;

[0052] When the load value is <0 (i.e., F < 0), the current load is a tensile load; when the load value is ≥0 (i.e., F ≥ 0), the current load is a resistance load.

[0053] One of the two displacement sensor assemblies 4.7 and 4.9 is used to detect the displacement of the valve core of the flow valve 4.6, and the other is used to detect the displacement of the valve core of the directional valve 4.8.

[0054] When the manual control mode is selected, the displacement closed-loop control mode is as follows: Closed-loop control is performed based on the error between the detection values ​​of the two displacement sensor assemblies 4.7 and 4.9 and the corresponding actual required displacement value to obtain a pair of control currents 1 and 2 applied to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies 4.1 and 4.2.

[0055] When the manual control mode is selected, the flow closed-loop control mode is as follows: Closed-loop control is performed based on the error between the real-time flow value of the corresponding valve port and the actual required flow value to obtain a pair of control currents 1 and 2 applied to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies 4.1 and 4.2.

[0056] Specifically, information from the first integrated temperature and pressure sensor 4.10, the second integrated temperature and pressure sensor 4.12, and the two displacement sensor assemblies 4.7 and 4.9 is collected. The actual flow rate Q at the valve port is calculated according to formula (2), and the error is calculated with the required flow rate Qreq. Flow closed-loop control is then performed, where the valve port temperature is used to correct the flow coefficient Cd.

[0057] (2)

[0058] Where: Q—valve orifice flow rate;

[0059] Cd—Valve orifice flow coefficient;

[0060] A(x) — Valve orifice area;

[0061] P1—Import pressure;

[0062] P2—Export pressure.

[0063] In this embodiment, a first integrated temperature and pressure sensor 4.10 is installed on the oil line entering the large cavity of the actuator cylinder 4.11, and a second integrated temperature and pressure sensor 4.12 is installed on the oil line entering the small cavity of the actuator cylinder 4.11.

[0064] When the manual control mode is selected, the pressure closed-loop control mode is as follows: based on the error between the pressure value detected by the first integrated temperature and pressure sensor 4.10 and the second integrated temperature and pressure sensor 4.12 and the actual required pressure value, closed-loop control is performed to obtain a pair of control currents 1 and 2 applied to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies 4.1 and 4.2.

[0065] A pressure reducing valve 4.3 is installed on the oil line that supplies oil to the two electro-hydraulic proportional pilot valve assemblies from the main pump 4.4, and a compensation valve 4.5 is installed on the oil line that connects the main pump 4.4 and the flow valve 4.6.

[0066] The following is in conjunction with the appendix Figure 2 The schematic diagram provides a detailed explanation of the multi-mode control of the dual-valve CAN bus control unit:

[0067] (1) Adaptive control mode: ① Set the equivalent areas Ah and Ar of the large and small chambers of the cylinder on the host computer 4.13, and set the numerical range of the first temperature and pressure integrated sensor 4.10 and the second temperature and pressure integrated sensor 4.12; ② Set the adaptive control mode on the host computer 4.13; ③ Load calculation: According to the dual valve core CAN bus control unit, the inlet and outlet temperature and pressure signals of the first temperature and pressure integrated sensor 4.10 and the second temperature and pressure integrated sensor 4.12, as well as the valve core displacement signals of the displacement sensor assembly 4.7 and the displacement sensor assembly 4.9 are collected, and the analog signals are converted into digital signals through A / D conversion. The load is calculated according to formula (1); ④ Tension load judgment: the tension load is judged according to the load judgment rules. If it is a tension load, the CAN bus controller will automatically match control mode one. If it is a resistance load, the CAN bus controller will automatically match control mode two; ⑤ The controller outputs control current one and control current two to control the electro-hydraulic proportional pilot valve assembly 4.1 and the electro-hydraulic proportional pilot valve assembly 4.2 reversing valve. At this time, the pilot oil will reach the right side of the flow valve 4.6 and the left / right position of the reversing valve 4.8, so that the oil of the main pump 4.4 reaches the large / small chamber of the oil cylinder 4.11.

[0068] (2) Manual control mode setting: ① Set the equivalent areas Ah and Ar of the large and small chambers of the hydraulic cylinder on the host computer 4.13, and set the value range of the first temperature and pressure integrated sensor 4.10 and the second temperature and pressure integrated sensor 4.12; ② Set the manual control mode on the host computer 4.13;

[0069] If a dual-valve-core displacement closed-loop control mode is set: based on the information from displacement sensor assembly 4.7 and displacement sensor assembly 4.9, and the error with the required displacement, displacement closed-loop control is performed. Finally, control current one and control current two are output to control the electro-hydraulic proportional pilot valve assembly 4.1 and electro-hydraulic proportional pilot valve assembly 4.2 to switch, so that the pilot oil acts on the left / right position of the switching valve 4.8 and the right position of the flow valve 4.6 respectively. The oil from the main pump 4.4 passes through the compensation valve 4.5, the flow valve 4.6, and the switching valve 4.8 to the large / small chamber of the oil cylinder 4.11.

[0070] If a dual-valve-core flow closed-loop control mode is set: calculate the valve port area A(x) based on the information from displacement sensor assembly 4.7 and displacement sensor assembly 4.9; calculate the flow coefficient Cd based on the temperature information from the first temperature and pressure integrated sensor 4.10 and the second temperature and pressure integrated sensor 4.12; calculate the valve port pressure difference ΔP based on the pressure sensor signals from the first temperature and pressure integrated sensor 4.10 and the second temperature and pressure integrated sensor 4.12; calculate the real-time valve port flow Q based on the calculated A(x), Cd, and ΔP according to formula (2); perform flow closed-loop control with the error of the required flow Qreq; and finally output control current one and control current two to control the electro-hydraulic proportional pilot valve assembly 4.1 and electro-hydraulic proportional pilot valve assembly 4.2 to switch, so that the pilot oil acts on the left / right position of the switching valve 4.8 and the right position of the flow valve 4.6 respectively; and the oil from the main pump 4.4 passes through the compensation valve 4.5, the flow valve 4.6, and the switching valve 4.8 to the large / small chamber of the oil cylinder 4.11.

[0071] If a dual-valve-core pressure closed-loop control mode is set: based on the pressure sensor signals from the first integrated temperature and pressure sensor 4.10 and the second integrated temperature and pressure sensor 4.12, the pressure is adjusted against the required pressure for closed-loop control. Finally, control current one and control current two are output to control the electro-hydraulic proportional pilot valve assembly 4.1 and electro-hydraulic proportional pilot valve assembly 4.2 to switch, so that the pilot oil acts on the left / right position of the switching valve 4.8 and the right position of the flow valve 4.6 respectively. The oil from the main pump 4.4 passes through the compensation valve 4.5, the flow valve 4.6, and the switching valve 4.8 to the large / small chamber of the oil cylinder 4.11.

[0072] Compared with existing technologies, the dual-valve CAN bus control unit and control method of the present invention have at least the following advantages:

[0073] 1. This invention designs a dual-valve-core CAN bus electronic control unit, which is used as an independent electronic control unit matched with the main valve. Compared with the original traditional electro-hydraulic valve, the electro-hydraulic valve matched with the CAN bus electronic control unit has higher control accuracy, more flexible control method, and smaller overall valve size.

[0074] 2. The present invention designs a dual-valve-core CAN bus electronic control unit, which integrates an LVDT displacement sensor, enabling closed-loop precise control of the main valve core position, allowing the main valve core to quickly and accurately reach the preset position, thereby improving the responsiveness and stability of the main valve;

[0075] 3. The present invention designs a dual-valve core CAN bus electronic control unit, which integrates a controller and can pre-decode the valve group control program, saving the debugging time of valve group control during the overall machine control.

[0076] 4. The CAN bus electronic control unit of the present invention, combined with the parameters of the hydraulic cylinder of the whole machine and the temperature and pressure sensor signal of the main valve port, can perform load condition calculation, realize the adaptive adjustment of the main valve flow and pressure closed-loop control algorithm, and improve the flexibility of main valve control;

[0077] 5. The CAN bus electronic control unit of the present invention is equipped with host computer application software, which can easily set valve parameters and configure control modes, reducing the requirements for users' professional skills and facilitating its widespread application.

[0078] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A dual-valve CAN bus control method, characterized in that, The system includes a main pump, flow valve, directional valve, actuator cylinder, and dual-valve CAN bus control unit. The dual-valve CAN bus control unit includes a control end cover and an end cover plate. The control end cover and the end cover plate are sealed together. The control end cover has two first mounting holes and two second mounting holes. An electro-hydraulic proportional pilot valve assembly is installed in each of the two first mounting holes, and a displacement sensor assembly is installed in each of the two second mounting holes. The control end cover has an oil inlet passage and an oil return passage that extend to the first mounting holes. A controller cover plate is installed on the control end cover, and a control board is installed inside the controller cover plate. A connector is installed on the controller cover plate, and the displacement sensor assembly is connected to the control board. One of the two displacement sensor assemblies is used to detect the displacement of the valve core of the flow valve, and the other is used to detect the displacement of the valve core of the reversing valve. The main pump supplies oil to the two electro-hydraulic proportional pilot valve assemblies, wherein the two working ports of one electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the directional valve, and the two working ports of the other electro-hydraulic proportional pilot valve assembly are respectively connected to the two ends of the flow valve. The two working ports of the directional valve are respectively connected to the large chamber and the small chamber of the actuator cylinder. The control method includes: Step S1: Set parameters on the host computer; Step S2: Set the host computer control mode. If it is the adaptive control mode, then execute steps S3 and S4; if it is the manual control mode, then execute step S5. Step S3: Calculate the load value; Step S4: Determine whether the load is a tensile load or a resistance load based on the load value in step S3. If it is a tensile load, then execute oil inlet speed control and oil return speed control; if it is a resistance load, then execute oil inlet speed control and oil return pressure control. Step S5: Set the control mode of each main valve core to: displacement closed-loop control mode, flow closed-loop control mode, or pressure closed-loop control mode. Step S6: Collect data and transmit it to the control board; in, The displacement closed-loop control mode: based on the error between the detection value of the two displacement sensor assemblies and the corresponding actual required displacement value, closed-loop control is performed to obtain a pair of control currents 1 and 2 used to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies. The flow closed-loop control mode: based on the error between the real-time flow value of the corresponding valve port and the actual required flow value, closed-loop control is performed to obtain a pair of control currents 1 and 2 applied to control the opening of the two electro-hydraulic proportional pilot valve assemblies. A first integrated temperature and pressure sensor is installed on the oil line entering the large chamber of the actuator cylinder, and a second integrated temperature and pressure sensor is installed on the oil line entering the small chamber of the actuator cylinder. The pressure closed-loop control mode is as follows: closed-loop control is performed based on the error between the pressure value detected by the first integrated temperature and pressure sensor and the second integrated temperature and pressure sensor and the actual required pressure value, to obtain a pair of control currents 1 and 2 used to control the opening degree of the two electro-hydraulic proportional pilot valve assemblies.

2. The control method as described in claim 1, characterized in that, When the load value is less than 0, the current load is a tensile load; when the load value is greater than or equal to 0, the current load is a resistance load.

3. The control method as described in claim 1, characterized in that, The axes of the two first mounting holes and the two second mounting holes are located in the same plane, and the two first mounting holes are located on both sides of the two second mounting holes.

4. The control method as described in claim 1, characterized in that, A pressure reducing valve is installed on the oil line that supplies oil from the main pump to the two electro-hydraulic proportional pilot valve assemblies, and a compensation valve is installed on the oil line connecting the main pump and the flow valve.

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