A deep-sea underwater electro-hydraulic actuator (EHA) system

Abstract

The application discloses a deep-sea underwater electro-hydraulic actuator (EHA) system. The system is powered by a power source module, the pressure balance between the system oil pressure and the external seawater pressure is controlled by a pressure compensation module, the oil flow and oil pressure are controlled by an integrated valve group module, the control instructions of the control module are executed by an actuator module, and the overall system is cooperatively controlled by the control module. The control system of the application compensates for the unbalanced pressure between the system and the deep-sea high water pressure environment through a pressure compensator, so as to reduce the influence of the deep-sea high water pressure environment, and at the same time, the pressure compensator serves as an oil tank to realize the miniaturization of the system and improve the reliability of the system when working underwater. The application optimizes the installation positions of the elements of the integrated valve group and the internal flow channels, reduces the pressure loss of the fluid in the internal flow channels, and improves the energy utilization efficiency of the deep-sea underwater electro-hydraulic actuator. The application can realize the operation of the asymmetric hydraulic cylinder in four working conditions in the deep sea, and can complete underwater high-precision movement.

Description

TECHNICAL FIELD

[0001] The application relates to an actuator control system and relates to the technical field of transmission and control. BACKGROUND

[0002] An actuator is a core unit for engineering equipment to realize movement and complete work. The actuator is generally divided into an electric actuator and a hydraulic actuator. The hydraulic actuator has the advantages of high power density, high output force and high external water pressure resistance, and thus dominates the field of marine engineering equipment, especially deep-sea application. However, with the increase of the underwater working depth, the hydraulic actuator faces problems such as low efficiency, high energy consumption, difficult maintenance and poor reliability. The deep-sea high water pressure environment tests the pressure resistance and signal stability of the control system, and easily causes leakage of the hydraulic pipeline, which is difficult to maintain effectively. SUMMARY

[0003] In order to solve the problems in the background art, the application provides a deep-sea underwater electro-hydraulic actuator (EHA) system. The application has the advantages of modularity, high integration, high energy utilization efficiency and strong adaptability to deep-sea environment. The application compensates the seawater pressure through a pressure compensation system, controls a variable-speed oil-immersed motor based on a control system, drives a plunger pump to provide pressure oil for an asymmetric hydraulic cylinder, and adjusts the motor speed to realize movement control of the deep-sea underwater electro-hydraulic actuator.

[0004] The technical scheme adopted by the application is as follows:

[0005] The deep-sea underwater electro-hydraulic actuator (EHA) system of the application comprises:

[0006] A power source module is used for power supply of the control system.

[0007] A pressure compensation module is connected with the power source module and is used for pressure balance of the control system oil and external seawater. The pressure compensation module serves as an oil tank of the control system.

[0008] An integrated valve group module is installed between the power source module and the pressure compensation module and is connected with the power source module and the pressure compensation module. The integrated valve group module comprises two balance valves and two overflow valves for oil pressure control.

[0009] An actuator module is installed on the integrated valve group module and is connected with the integrated valve group module. The actuator module comprises an asymmetric hydraulic cylinder.

[0010] A control module is installed on the power source module and the asymmetric hydraulic cylinder and is used for cooperative control of the power source module, the pressure compensation module and the asymmetric hydraulic cylinder of the actuator module.

[0011] The integrated valve group module further comprises a flow matching valve and an integrated valve block, the integrated valve block is installed between the power source module and the pressure compensation module, two balance valves are installed on one side of the integrated valve block and are located inside the power source module, and the flow matching valve and two overflow valves are installed on the other side of the integrated valve block and are located inside the pressure compensation module; the power source module comprises a variable-speed immersed oil motor, a bidirectional plunger pump and a power source shell, the power source shell is installed on the side of the integrated valve block where the two balance valves are located, the two balance valves are located inside the power source shell, the variable-speed immersed oil motor and the plunger pump are installed inside the power source shell, the output shaft of the variable-speed immersed oil motor is connected to the output shaft of the bidirectional plunger pump through a shaft coupling and a spline, and the pump body of the plunger pump is installed at the center of the side of the integrated valve block where the two balance valves are located and is arranged in a spaced manner with the two balance valves; the oil outlet and the oil inlet of the plunger pump are communicated with a first flow channel a and a second flow channel b in the integrated valve block respectively, the first flow channel a is divided into a third flow channel a1 and a fourth flow channel a2, the second flow channel b is divided into a fifth flow channel b1 and a sixth flow channel b2, the third flow channel a1 is communicated with the oil outlet of the overflow valve of the first balance valve and the oil inlet of the one-way valve, the fourth flow channel a2 is communicated with the A port and the C1 port of the flow matching valve, the fifth flow channel b1 is communicated with the oil outlet of the overflow valve of the second balance valve and the oil inlet of the one-way valve, the sixth flow channel b2 is communicated with the B port and the C2 port of the flow matching valve, the oil inlet of the overflow valve of the first balance valve and the oil outlet of the one-way valve are communicated with a seventh flow channel c in the integrated valve block, the oil outlet of the overflow valve of the second balance valve and the oil inlet of the one-way valve are communicated with an eighth flow channel d in the integrated valve block, the seventh flow channel c is divided into a ninth flow channel c1 and a tenth flow channel c2, the eighth flow channel d is divided into an eleventh flow channel d1 and a twelfth flow channel d2, the ninth flow channel c1 and the eleventh flow channel d1 are respectively communicated with the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder of the actuator module, the tenth flow channel c2 is communicated with the oil inlet of the first overflow valve, the twelfth flow channel d2 is communicated with the oil inlet of the second overflow valve, the oil outlets of the two overflow valves are connected and are communicated with the T port of the flow matching valve through a thirteenth flow channel e in the integrated valve block; the pressure compensation module is communicated with the T port of the flow matching valve and the oil supplement port of the bidirectional plunger pump through a fourteenth flow channel f1 and a fifteenth flow channel f2 in the integrated valve block respectively; the control module is installed on the power source shell, and the control module is electrically connected with the variable-speed immersed oil motor and the asymmetric hydraulic cylinder.

[0012] The pressure compensation module adopts a skin bag type pressure compensator, the body of the pressure compensator is installed on the other side of the integrated valve block where the flow matching valve and the two overflow valves are located, the flow matching valve and the two overflow valves are located in the hydraulic oil filled in the pressure compensator, and the pressure compensator serves as an oil tank of the control system to supply oil.

[0013] The actuator module further comprises a connecting member, which comprises a sub-valve block and two steel pipes, the cylinder body of the asymmetric hydraulic cylinder is installed on the side of the integrated valve block through the sub-valve block, and the two steel pipes are installed on the cylinder body of the asymmetric hydraulic cylinder and respectively communicate the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder with the ninth flow channel c1 and the eleventh flow channel d1 inside the integrated valve block.

[0014] The control module comprises a displacement sensor, a composite transmission cable group, an oil-immersed sealed cabin, a main controller and a motor driver, the displacement sensor is installed on the piston rod of the asymmetric hydraulic cylinder, the oil-immersed sealed cabin is installed on the power source shell through screw threads, and the main controller and the motor driver are installed inside the oil-immersed sealed cabin through bolts; the composite transmission cable comprises a direct current cable, a controller area network (CAN) first bus communication cable and a second bus communication cable, the main controller is electrically connected to the CAN communication interface of the displacement sensor and the CAN communication interface of the motor driver through the second CAN communication interface and the second bus communication cable, and the main controller is electrically connected to an external host computer through the first CAN communication interface and the first bus communication cable; the direct current cable is a direct current power supply, which respectively supplies power to the main controller and the motor driver; the oil-immersed sealed cabin is connected to a pressure compensation module inside, and the motor driver is electrically connected to a variable-speed oil-immersed motor.

[0015] The main controller is internally integrated with a trajectory planning algorithm, a state observation algorithm and a position control algorithm, the host computer sends a control instruction to the main controller through the first bus communication cable, the main controller receives the running state of the asymmetric hydraulic cylinder obtained by the displacement sensor and the running state of the variable-speed oil-immersed motor obtained by the motor driver through the second bus communication cable, the motion state of the asymmetric hydraulic cylinder comprises displacement and speed information of the piston rod, and the running state of the variable-speed oil-immersed motor comprises motor speed and torque information; after the host computer sends a position control instruction, the main controller obtains an expected trajectory according to a preset trajectory instruction and through the trajectory planning algorithm, the expected trajectory comprises an expected position, an expected speed and an expected acceleration, the running state of the variable-speed oil-immersed motor and the asymmetric hydraulic cylinder and the expected trajectory are processed by the state observation algorithm to obtain two cavity pressure values of the asymmetric hydraulic cylinder and an external load force, after receiving a speed instruction, the two cavity pressure values of the asymmetric hydraulic cylinder and the external load force are processed by the position control algorithm to obtain an expected speed of the variable-speed oil-immersed motor, which is then transmitted to the variable-speed oil-immersed motor for speed control through the pulse width modulation (PWM) modulation of the motor driver, after the control is completed, the main controller transmits the real-time running state of the variable-speed oil-immersed motor and the asymmetric hydraulic cylinder to the host computer for display and real-time state monitoring.

[0016] The control system drives the plunger pump by the variable speed oil-immersed motor, controls the hydraulic oil flow direction of the asymmetric hydraulic cylinder, and realizes four working conditions of the asymmetric hydraulic cylinder, including resistance retracting condition, overrun retracting condition, resistance extending condition and overrun extending condition.

[0017] In the resistance retracting condition, the pressure of the rod cavity of the asymmetric hydraulic cylinder is higher than that of the rodless cavity, the plunger pump driven by the variable speed oil-immersed motor sucks oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the first balance valve, generates control pressure at the control port of the overflow valve of the second balance valve, so that the overflow valve of the second balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the first balance valve flows into the rod cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the first overflow valve, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder is controlled through the second overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder flows back to the oil inlet of the plunger pump through the overflow valve of the second balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the A port of the flow matching valve, generates high control pressure at the C1 port of the flow matching valve, the hydraulic oil flowing out of the rodless cavity of the asymmetric hydraulic cylinder flows to the B port of the flow matching valve, generates low control pressure at the C2 port of the flow matching valve, so that the A port of the flow matching valve is closed and the B port and the T port are open, the excess hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder returns to the pressure compensator through the B port and the T port of the flow matching valve, and the unmatched flow is compensated.

[0018] In the resistance retracting condition, the pressure of the rod cavity of the asymmetric hydraulic cylinder is higher than that of the rodless cavity, the plunger pump driven by the variable speed oil-immersed motor sucks oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the first balance valve, generates control pressure at the control port of the overflow valve of the second balance valve, so that the overflow valve of the second balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the first balance valve flows into the rod cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the first overflow valve, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder is controlled through the second overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder flows back to the oil inlet of the plunger pump through the overflow valve of the second balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the A port of the flow matching valve, generates low control pressure at the C1 port of the flow matching valve, the hydraulic oil flowing out of the rodless cavity flows to the B port of the flow matching valve, generates high control pressure at the C2 port of the flow matching valve, so that the B port of the flow matching valve is closed and the A port and the T port are open, the excess hydraulic oil at the oil outlet of the plunger pump returns to the pressure compensator through the A port and the T port of the flow matching valve, and the unmatched flow is compensated.

[0019] In the resistance extension working condition, the pressure in the rod cavity of the asymmetric hydraulic cylinder is lower than the pressure in the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the second balance valve, and control pressure is generated at the control port of the overflow valve of the first balance valve, so that the overflow valve of the first balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the second balance valve flows into the rodless cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the second overflow valve, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder is controlled through the first overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the first balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the B port of the flow matching valve, and high control pressure is generated at the C2 port of the flow matching valve, the hydraulic oil flowing out of the rod cavity of the asymmetric hydraulic cylinder flows to the A port of the flow matching valve, and low control pressure is generated at the C1 port of the flow matching valve, so that the B port of the flow matching valve is closed and the A port and the T port are open, and the hydraulic oil in the pressure compensator flows into the oil inlet of the plunger pump through the A port and the T port of the flow matching valve, so as to compensate for the unmatched flow.

[0020] In the resistance extension working condition, the pressure in the rod cavity of the asymmetric hydraulic cylinder is lower than the pressure in the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the second balance valve, and control pressure is generated at the control port of the overflow valve of the first balance valve, so that the overflow valve of the first balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the second balance valve flows into the rodless cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the second overflow valve, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder is controlled through the first overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the first balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the B port of the flow matching valve, and high control pressure is generated at the C2 port of the flow matching valve, the hydraulic oil flowing out of the rod cavity of the asymmetric hydraulic cylinder flows to the A port of the flow matching valve, and low control pressure is generated at the C1 port of the flow matching valve, so that the B port of the flow matching valve is closed and the A port and the T port are open, and the hydraulic oil in the pressure compensator flows into the oil inlet of the plunger pump through the A port and the T port of the flow matching valve, so as to compensate for the unmatched flow.

[0021] The application realizes the balance of system oil pressure and external seawater pressure through a pressure compensator, and simultaneously supplies oil to the hydraulic system as an oil tank to reduce the overall volume of the equipment; the optimized design of the integrated valve block is realized through the optimization of the relative installation relationship of elements and fluid mechanics simulation by Fluent software, and the energy utilization efficiency is improved; the anti-electromagnetic interference of the system is improved and the control performance of the system is improved through the use of CAN2.0 bus communication in the form of differential digital quantity to transfer data, and the design of the modular pressure-resistant oil-immersed control system.

[0022] The application integrates the core elements of the hydraulic system together, and uses a power cable to replace the hydraulic pipeline to transfer energy. While retaining the advantages of the hydraulic system, the problem of poor reliability caused by the complex hydraulic pipeline is effectively avoided, and the application has the characteristics of high integration, miniaturization and distributed installation, and the advantages of more convenient maintenance, and has a wide application prospect in the field of deep-sea equipment.

[0023] The application has the following beneficial effects:

[0024] 1. Compared with the traditional land electro-hydraulic actuator system, the application compensates the unbalanced pressure between the electro-hydraulic actuator and the deep-sea high water pressure environment through a pressure compensator, so as to reduce the influence of the deep-sea high water pressure environment on the hydraulic system, and simultaneously the pressure compensator supplies oil to the electro-hydraulic actuator as an oil tank, realizes the miniaturization of the electro-hydraulic actuator, and improves the reliability of the electro-hydraulic actuator system when working underwater.

[0025] 2. The application optimizes the installation positions of the elements of the integrated valve group, and realizes the optimization of the internal flow channel of the integrated valve block through fluid mechanics simulation by Fluent software, reduces the pressure loss of the fluid in the flow channel, and improves the energy utilization efficiency of the deep-sea underwater electro-hydraulic actuator.

[0026] 3. The application can control the deep-sea underwater electro-hydraulic actuator to complete underwater high-precision movement through the control system, realizes the operation in four working conditions of resistance retraction, overrun retraction, resistance extension and overrun extension, and the underwater movement control precision reaches 1mm. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a whole structure diagram of the application;

[0028] Figure 2 It is a whole structure sectional view of the application;

[0029] Figure 3 It is a whole structure side view of the application;

[0030] Figure 4 It is an element installation schematic diagram of the integrated valve group module of the application;

[0031] Figure 5Fig. 1 is a schematic diagram of the plunger pump and integrated valve group of the present application, wherein, Figure 5 Fig. 1(a) is a front view of the plunger pump and integrated valve of the present application, Figure 5 Fig. 1(b) is a left view of the plunger pump and integrated valve group of the present application, Figure 5 Fig. 1(c) is a right view of the plunger pump and integrated valve group of the present application;

[0032] Figure 6 Fig. 2 is a schematic diagram of the pressure compensator of the present application, wherein, Figure 6 Fig. 2(a) is a structural diagram of the pressure compensator of the present application, Figure 6 Fig. 2(b) is a sectional view of the pressure compensator of the present application;

[0033] Figure 7 Fig. 3 is a schematic diagram of the control system of the present application;

[0034] Figure 8 Fig. 4 is a schematic diagram of the hydraulic system of the present application;

[0035] Figure 9 Fig. 5 is a schematic diagram of the flow channel of the integrated valve block of the present application, wherein, Figure 9 Fig. 5(a) is a schematic diagram of the right-angle type flow channel of the integrated valve block of the present application, Figure 9 Fig. 5(b) is a schematic diagram of the Z type flow channel of the integrated valve block of the present application;

[0036] Figure 10 Fig. 6 is a schematic diagram of the trajectory of the piston rod of the asymmetric hydraulic cylinder in the example of the present application, wherein, Figure 10 Fig. 6(a) is a schematic diagram of the desired trajectory of the piston rod of the asymmetric hydraulic cylinder in the example of the present application, Figure 10 Fig. 6(b) is a schematic diagram of the actual trajectory of the piston rod of the asymmetric hydraulic cylinder in the example of the present application, Figure 10 Fig. 6(c) is a schematic diagram of the trajectory tracking error of the piston rod of the asymmetric hydraulic cylinder in the example of the present application;

[0037] Fig. 1 is a schematic diagram of the plunger pump and integrated valve group of the present application, wherein, DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0039] As shown in Figure 1 , Figure 2 and Figure 3 , the deep-sea underwater electro-hydraulic actuator (EHA) system of the present application comprises a power source module, a pressure compensation module, an integrated valve group module, an actuator module and a control module 11. The power source module provides power for the control system. The pressure compensation module is connected to the power source module and is used to balance the oil pressure of the control system and the external seawater pressure. The pressure compensation module serves as the oil tank of the control system. The integrated valve group module is installed between the power source module and the pressure compensation module and is connected to the power source module and the pressure compensation module. The integrated valve group module includes two balance valves 5.1, 5.2 and two overflow valves 6.1, 6.2 for oil pressure control. The actuator module is installed on and connected to the integrated valve group module. The actuator module includes an asymmetric hydraulic cylinder 7. The control module 11 is installed on the power source module and the asymmetric hydraulic cylinder 7 and is used for the coordinated control of the power source module, the pressure compensation module and the asymmetric hydraulic cylinder 7 of the actuator module.

[0040] As shown in Figure 4 , Figure 5 (a), Figure 5 (b), Figure 5 (c), and Figure 8As shown, the integrated valve group module further comprises a flow matching valve 4 and an integrated valve block 9, the integrated valve block 9 is installed between the power source module and the pressure compensation module, two balance valves 5.1, 5.2 are installed on one side of the integrated valve block 9 and located inside the power source module, the flow matching valve 4 and two overflow valves 6.1, 6.2 are installed on the other side of the integrated valve block 9 and located inside the pressure compensation module; the power source module comprises a variable speed immersed oil motor 1, a bidirectional plunger pump 2 and a power source shell 8, the power source shell 8 is installed on the side of the integrated valve block 9 where the two balance valves 5.1, 5.2 are located, the two balance valves 5.1, 5.2 are located inside the power source shell 8, the variable speed immersed oil motor 1 and the plunger pump 2 are installed inside the power source shell 8, the output shaft of the variable speed immersed oil motor 1 is connected to the output shaft of the bidirectional plunger pump 2 through a shaft coupling and a spline, to provide hydraulic oil for the integrated valve group module, the mounting surface of the variable speed immersed oil motor 1 is threadedly connected to the end surface G of the bidirectional plunger pump 2; the pump body of the plunger pump 2 is installed at the center of the side of the integrated valve block 9 where the two balance valves 5.1, 5.2 are located and is arranged in a spaced manner with the two balance valves 5.1, 5.2; the oil outlet and the oil inlet of the plunger pump 2 are respectively communicated with a first flow channel a and a second flow channel b inside the integrated valve block 9, the first flow channel a is divided into a third flow channel a1 and a fourth flow channel a2, the second flow channel b is divided into a fifth flow channel b1 and a sixth flow channel b2, the oil outlet of the overflow valve of the first balance valve 5.1 and the oil inlet of the one-way valve of the third flow channel a1 are communicated, the fourth flow channel a2 is respectively communicated with the A port and the C1 port of the flow matching valve 4 through a normal oil way and a control oil way, the oil outlet of the overflow valve of the second balance valve 5.2 and the oil inlet of the one-way valve of the fifth flow channel b1 are communicated, the sixth flow channel b2 is respectively communicated with the B port and the C2 port of the flow matching valve 4 through a normal oil way and a control oil way, the oil inlet of the overflow valve of the first balance valve 5.1 and the oil outlet of the one-way valve are communicated with a seventh flow channel c inside the integrated valve block 9, the oil outlet of the overflow valve of the second balance valve 5.2 and the oil inlet of the one-way valve are communicated with an eighth flow channel d inside the integrated valve block 9, the seventh flow channel c is divided into a ninth flow channel c1 and a tenth flow channel c2, the eighth flow channel d is divided into an eleventh flow channel d1 and a twelfth flow channel d2, the ninth flow channel c1 and the eleventh flow channel d1 are respectively communicated with the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder 7 of the actuator module, the tenth flow channel c2 is communicated with the oil inlet of the first overflow valve 6.1, the twelfth flow channel d2 is communicated with the oil inlet of the second overflow valve 6.2, the oil outlets of the two overflow valves 6.1, 6.2 are connected and are communicated to the T port of the flow matching valve 4 through a thirteenth flow channel e inside the integrated valve block 9; the pressure compensation module is respectively communicated to the T port of the flow matching valve 4 and the oil supplement port of the bidirectional plunger pump 2 through a fourteenth flow channel f1 and a fifteenth flow channel f2 inside the integrated valve block 9; the control module 11 is installed on the power source shell 8, the control module 11 is electrically connected to the variable speed immersed oil motor 1 and the asymmetric hydraulic cylinder 7.

[0041] The power source shell 8 is a pressure-resistant shell, adopts a cylindrical outer contour, and is provided with a rectangular opening on the side surface for mounting the control module 11; the integrated valve block 9 is provided with plug-in threaded holes for mounting various valves; the integrated valve block 9 is also provided with a hollow structure for reducing weight and facilitating taking; the second end surface H of the bidirectional plunger pump 11 is threadedly connected with the first end surface I of the integrated valve block 9, so that the oil inlet and the oil outlet of the bidirectional plunger pump 11 are in communication with the orifices of the integrated valve block 9.

[0042] The integrated valve block 9 of the present application is designed as follows:

[0043] The elements of the integrated valve block 9 are distributed on two surfaces, the flow matching valve 4 and the overflow valves 6.1 and 6.2 are placed on the same side, and the plunger pump 2 and the balance valves 5.1 and 5.2 are placed on the opposite side. Such an arrangement scheme can improve the utilization rate of the integrated valve block 9, and can make the line arrangement clear after the oil pipe is connected, and the elements do not affect each other when disassembled. After the element arrangement of the integrated valve block 9 is completed, flow channels are processed inside the integrated valve block 9. The design of the flow channels considers pressure loss. The integrated valve block 9 is optimized based on the fluid mechanics simulation results of the Fluent software. The pressure loss conditions at the right-angle flow channels and Z-shaped flow channels are analyzed. The flow channels are optimized under the condition of subtractive manufacturing: when designing and processing the right-angle flow channels, the length of the tool tip cavity is shortened and the tool tip cavity is directed towards the oil inlet, and when designing and processing the Z-shaped flow channels, the distance between the two flow channels is shortened, and the process hole diameter is increased without affecting the minimum wall thickness of the integrated valve block, so that the pressure loss of the fluid in the flow channels is significantly reduced, and the energy utilization efficiency is improved.

[0044] In the specific implementation of the present application, the right-angle flow channels are numerically simulated. The flow channel model is shown in (a) of Figure 9 , which is formed by two staggered flow channels, and one end of one flow channel forms a tool tip cavity. When setting parameters in the Fluent software, the Standard k-ε turbulent flow model is selected, the inlet flow rate is 2 m / s, the outlet pressure is 10 MPa, the fluid medium is selected as No. 46 hydraulic oil, the density is 900 kg / m 2 , and the dynamic viscosity is 0.0261 N·s / m 2 . Through simulation analysis, the relationship between the pressure difference of the hydraulic oil flowing into / out of the right-angle flow channel and the length of the tool tip cavity and the direction of the tool tip is obtained, as shown in Table 1.

[0045] Table 1

[0046]

[0047] As shown in Table 1, the pressure loss is positively correlated with the length of the cutting edge cavity, and the pressure loss is less when the cutting edge cavity faces the oil inlet. Therefore, when designing and machining right-angled flow channels, shortening the length of the cutting edge cavity and positioning it towards the oil inlet reduces the pressure loss of the fluid inside the flow channel, thereby improving energy utilization efficiency.

[0048] Numerical simulation of the Z-shaped flow channel was performed, and the flow channel model is as follows: Figure 9 As shown in (b), this is formed when the process orifice simultaneously penetrates two parallel flow channels. The distance T between the two parallel flow channels and the diameter U of the process orifice are parameters that can be optimized. When setting parameters in Fluent software, the Standard k-ε turbulence model is selected, with an inlet velocity of 2 m / s, an outlet pressure of 10 MPa, and the fluid medium being No. 46 hydraulic oil with a density of 900 kg / m³. 2 The dynamic viscosity is 0.0261 N·s / m. 2 Through simulation analysis, the relationship between the pressure difference before and after the hydraulic oil flows into / out of the Z-shaped flow channel and the distance T between the two parallel flow channels was obtained, as shown in Table 2.

[0049] Table 2

[0050]

[0051] As shown in Table 2, the pressure loss is positively correlated with the distance T between the two parallel flow channels, and the pressure loss is less when the blade tip cavity approaches the oil inlet. Therefore, shortening the distance between the two flow channels during the design and fabrication of the Z-shaped flow channel effectively reduces pressure loss within the integrated valve block 9.

[0052] Furthermore, the process orifice diameters U were set to 4mm, 5mm, 6mm, and 8mm, and the diameters of the two parallel flow channels were set to 5mm. With the other simulation parameters remaining unchanged, the relationship between the pressure difference before and after the hydraulic oil flows into / out of the Z-shaped flow channel and the process orifice diameter U was obtained, as shown in Table 3.

[0053] Table 3

[0054]

[0055] As shown in Table 3, the pressure loss is negatively correlated with the process orifice diameter. Therefore, when designing and manufacturing the Z-shaped flow channel, without affecting the minimum wall thickness of the integrated valve block 9, increasing the process orifice diameter can effectively reduce the pressure loss inside the integrated valve block 9.

[0056] like Figure 6 (a) and Figure 6As shown in (b), the pressure compensation module adopts a bladder type pressure compensator 3, the body of the pressure compensator 3 is installed on the other side of the integrated valve block 9 where the flow matching valve 4 and the two overflow valves 6.1, 6.2 are located, the flow matching valve 4 and the two overflow valves 6.1, 6.2 are located in the hydraulic oil filled in the pressure compensator 3, and the pressure compensator 3 serves as an oil tank of the control system to supply oil. The bladder type pressure compensator 3 is composed of an oil bag shell, a compensation oil bag, an oil bag flange and a clamping ring. The compensation oil bag is connected with the oil bag flange through the clamping ring, the oil bag shell is connected with the oil bag flange through a tooth-shaped structure, and the oil bag flange is fixedly connected with the second end surface J of the integrated valve block 9 through threaded connection. The compensation oil bag is made of butyl rubber, and the oil bag shell is made of POM acetal copolymer. With the change of seawater pressure, the compensation oil bag shrinks and expands in the oil bag shell, so as to balance the system oil pressure and the external seawater pressure, and at the same time, as an oil tank, the pressure compensator 3 supplies oil for the hydraulic system to reduce the overall volume of the equipment.

[0057] The present application realizes the compensation of the unbalanced pressure between the system interior and the deep sea high water pressure environment through the pressure compensator 3, and the working principle is as follows:

[0058] The pressure compensator 3 serves as an oil tank to supply oil for the hydraulic system to reduce the overall volume of the equipment, and at the same time, the pressure compensator 3 realizes the balance between the system oil pressure and the external seawater pressure through the compensation of oil, and has three states of initial state, pressure increasing state and pressure decreasing state in the working process. In the initial state, the compensation oil bag is pre-charged with a certain pressure of hydraulic oil, the external pressure and the internal pressure of the hydraulic system are in a balanced state, and the compensation oil bag is neither compressed inward nor expanded outward; in the pressure increasing state, the external pressure is transmitted to the surface of the compensation oil bag, so that the compensation oil bag is compressed inward under the action of the pressure, the hydraulic oil is pushed into the hydraulic system, the internal pressure of the hydraulic system is increased, and a new balance with the external water pressure is reached; in the pressure decreasing state, the surface pressure of the compensation oil bag is reduced, the internal pressure of the hydraulic system pushes the compensation oil bag to expand outward, the hydraulic oil flows from the hydraulic system into the compensation oil bag, the internal pressure of the hydraulic system is reduced, and a new balance with the external water pressure is reached. Based on the above three states, the pressure compensator 3 can realize dynamic compensation of the oil return pressure of the underwater hydraulic system under the condition of large range change of working depth, and the dynamic balance ensures that the hydraulic system will not fail due to too high or too low pressure.

[0059] The actuator module further comprises a connecting piece 10, which comprises a sub-valve block and two steel pipes, the cylinder body of the asymmetric hydraulic cylinder 7 is installed on the side of the integrated valve block 9 through the sub-valve block, and the two steel pipes are installed on the cylinder body of the asymmetric hydraulic cylinder 7 and respectively communicate the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder 7 with the ninth flow channel c1 and the eleventh flow channel d1 inside the integrated valve block 9. The actuator module uses 0Cr17Ni4Cu4Nb steel, the inner wall of the cylinder of the asymmetric hydraulic cylinder 7 at the contact position with the piston and the end cover of the asymmetric hydraulic cylinder 7 at the contact position with the piston rod adopt a bidirectional dynamic sealing structure of Y-shaped sealing ring back-to-back installation. The sub-valve block is connected to the first end face K of the integrated valve block 9, two oil passages are processed on the first end face K, which are respectively connected to the first side end face L and the second side end face M of the sub-valve block through internal flow channels, and the first side end face L and the second side end face M of the sub-valve block are welded with steel pipes. The rod cavity and the rodless cavity of the asymmetric hydraulic cylinder 7 are both processed with through holes on the side of the cylinder, and are connected with the two steel pipes through welding, so as to realize the connection of the first side end face L and the rod cavity and the connection of the second side end face M and the rodless cavity. The first end face K of the sub-valve block is connected with the second end face N of the integrated valve block 9 through threads, so as to realize the communication of the actuator module and the integrated valve block 9.

[0060] As shown in Figure 7 The control module 11 comprises a displacement sensor 12, a composite transmission cable group 13, an oil-immersed sealing cabin 14, a main controller 15 and a motor driver 16. The displacement sensor 12 is installed on the piston rod of the asymmetric hydraulic cylinder 7, the oil-immersed sealing cabin 14 is installed on the power source shell 8 through threads, and the main controller 15 and the motor driver 16 are installed inside the oil-immersed sealing cabin 14 through bolts. The composite transmission cable 13 comprises a 300V direct current cable, a 24V direct current cable, a first bus communication cable and a second bus communication cable of a controller area network (CAN). The main controller 15 is electrically connected with the CAN communication interface of the 24V power supply displacement sensor 12 and the CAN communication interface of the 300V power supply motor driver 16 through the second CAN communication interface and the second bus communication cable. The main controller 15 is electrically connected with the external host computer through the first CAN communication interface and the first bus communication cable. The direct current cable provides 24V and 300V direct current power sources respectively for the main controller 15 and the motor driver 16. The slot of the composite transmission cable group 13 is connected with the plug of the cable-sealing cabin connecting piece. The connecting piece is connected with the main controller 15 and the motor driver 16 through power lines and data lines, and is fixed to the outside of the oil-immersed sealing cabin 14 through thread connection. The inside of the oil-immersed sealing cabin 14 is communicated with a pressure compensation module, and high-pressure oil is provided by the pressure compensator 3 to balance the high water pressure in the deep sea. The motor driver 16 is electrically connected with the variable speed oil-immersed motor 1.

[0061] The main controller 15 is internally integrated with a trajectory planning algorithm, a state observation algorithm and a position control algorithm, which are used to complete the precise motion control of the underwater electro-hydraulic actuator; in actual control, initialization is first performed after the system is powered on, including interrupt initialization, communication initialization and data initialization, and at the same time, the main controller 15 supplies power to the displacement sensor 12; the host computer sends a control instruction to the main controller 15 through the first bus communication cable, and the main controller 15 analyzes the control instruction, which includes a start instruction and a working mode selection instruction; after sending the start instruction, the main controller 15 sends a start command to the displacement sensor 12 and the motor driver 16, and the displacement sensor 12 and the motor driver 16 start to feed back state information; the working mode selection instruction includes a return-to-original position instruction, a position control instruction and a speed instruction; when the host computer sends the return-to-original position instruction, the main controller 15 controls the speed of the variable-speed oil-immersed motor 1, thereby controlling the asymmetric hydraulic cylinder 7 to quickly return to the initial position; other control instructions, such as instructions for controlling the extension and retraction of the piston rod of the asymmetric hydraulic cylinder 7; the main controller 15 receives the running state of the asymmetric hydraulic cylinder 7 obtained by the displacement sensor 12 and the running state of the variable-speed oil-immersed motor 1 obtained by the motor driver 16 through the second bus communication cable; the motion state of the asymmetric hydraulic cylinder 7 includes displacement and speed information of the piston rod, and the running state of the variable-speed oil-immersed motor 1 includes motor speed and torque information; after the host computer sends the position control instruction, the main controller 15 obtains the expected trajectory according to the preset trajectory instruction and through the trajectory planning algorithm, which includes the expected position, the expected speed and the expected acceleration; the running state of the variable-speed oil-immersed motor 1 and the asymmetric hydraulic cylinder 7 and the expected trajectory are processed by the state observation algorithm to obtain the two-cavity pressure value and the external load force of the asymmetric hydraulic cylinder 7; after receiving the speed instruction, the two-cavity pressure value and the external load force of the asymmetric hydraulic cylinder 7 are processed by the position control algorithm to obtain the expected speed of the variable-speed oil-immersed motor 1, which is then transmitted to the variable-speed oil-immersed motor 1 for speed control through the pulse width modulation PWM modulation of the motor driver 16; after the control is completed, the main controller 15 transmits the real-time running state of the variable-speed oil-immersed motor 1 and the asymmetric hydraulic cylinder 7 to the host computer for display and real-time state monitoring.

[0062] The displacement sensor 12 is an internal magnetostrictive sensor installed inside the asymmetric hydraulic cylinder 7, the guide rod of which is integrated with the piston rod of the asymmetric hydraulic cylinder 7, the magnetic ring moves together with the piston, the running state of the asymmetric hydraulic cylinder 7 is measured in real time, and is connected with the main controller 15 through the CAN bus, the actual position and running speed can be converted into digital quantity and sent to the main controller 15 in the form of CAN communication. The oil-immersed sealed cabin 14 is a steel open cabin. The main controller 15 is used for event processing and calculation of underwater electro-hydraulic actuator control algorithm, the hardware circuit thereof includes a main control chip, a power supply module, a CAN communication module and a serial SWD (Serial Wire Debug) debugging module, wherein the main control chip adopts an ARM Cortex-M4 core microcontroller, the system clock of which can reach 168 MHz at most, and supports a floating-point operation unit FPU (Floating-Point Unit) single-precision floating-point number operation and an enhanced digital signal processor DSP (Digital Signal Processing) instruction set, performs fast floating-point hardware calculation, and can perform real-time time processing and high-precision control algorithm calculation tasks. The trajectory planning algorithm of the main controller 15 initializes the trajectory according to the set maximum stroke, maximum speed and maximum acceleration information, and pre-calculates a point-to-point running trajectory containing start, acceleration, constant speed and deceleration. The state observation algorithm of the main controller 15 estimates the pressure values of the two chambers of the asymmetric hydraulic cylinder 7 through the design of a reduced-order observer based on the displacement signal and the speed signal of the displacement sensor, and further calculates the external load force based on the pressure difference of the two chambers and the effective area of the piston. The position control algorithm of the main controller 15 adopts adaptive robust control, designs an online parameter estimation algorithm and an adaptive model compensation control law, compensates the model nonlinearity and parameter uncertainty online, then designs a robust control law according to the parameter limit variation range and external disturbance, and suppresses the model deviation and parameter estimation deviation. The main controller 15 only collects data and transmits information through the CAN bus, improves the anti-interference ability in the data transmission process, and reduces the number of external interfaces and the cost. The motor driver 16 is connected with the ship-mounted power distribution cabin through the composite transmission cable group 13, is connected with the main controller 15 through the CAN bus, can receive the speed command sent by the main controller 15 from the CAN bus, performs motor speed control of the variable-speed oil-immersed motor 1 through PWM modulation, and can feedback the actual speed and torque data of the variable-speed oil-immersed motor 1 to the main controller 15 in the form of CAN signal. The communication mode only uses the CAN2.0 bus communication in the form of differential digital quantity to transmit data, has high anti-electromagnetic interference and real-time performance, and can be used for long-distance data transmission between the host computer and the main controller 15, and communication between the main controller 15 and the motor driver 16 and the displacement sensor 12.

[0063] The control system of the application can realize automatic return to the origin, constant speed control, motion trajectory planning and trajectory tracking, etc. At the same time, the displacement and speed information of the asymmetric hydraulic cylinder 7 and the speed and torque information of the variable speed oil-immersed motor 1 are used to calculate the pressure values of the two chambers of the asymmetric hydraulic cylinder 7 for motion control algorithm. When the underwater electro-hydraulic actuator is operated, the main controller 15 obtains the control instructions of the host computer from the CAN bus of the composite transmission cable group 13. The trajectory planning algorithm module automatically generates point-to-point position, speed and acceleration trajectory planning according to the set target point. At the same time, the main controller 15 collects the position and speed signals of the displacement sensor 12 and the speed and torque signals of the motor driver 16 from the CAN bus. The two-chamber pressure of the asymmetric hydraulic cylinder 7 required for motion control is calculated through the state observation algorithm. After the control algorithm module calculates the motor speed of the variable speed oil-immersed motor 1 required for trajectory tracking according to the running state of the deep-sea electro-hydraulic actuator, it is sent to the motor driver 16 through the CAN bus. At the same time, the running state information of the electro-hydraulic actuator can be sent back to the shipborne control module through the composite transmission cable group 13, so as to monitor the running state of the system.

[0064] The function of the application and its hydraulic principle are as follows:

[0065] The control system drives the plunger pump 2 through the variable speed oil-immersed motor 1, controls the flow direction of the hydraulic oil to the asymmetric hydraulic cylinder 7, realizes the four working conditions of the asymmetric hydraulic cylinder 7, and in the working state, the pressure compensator 3 completes the balance of the system oil pressure and the external seawater pressure, and at the same time as the oil tank, supplies oil to the plunger pump 2 through the flow passage f2 to reduce the overall volume of the equipment. The four working conditions include resistance retraction working condition, overrun retraction working condition, resistance extension working condition and overrun extension working condition, which are as follows:

[0066] In the resistance retracting working condition, the piston rod of the asymmetric hydraulic cylinder 7 retracts, the external load force direction of the piston rod is opposite to the movement direction of the piston rod, the rod cavity pressure of the asymmetric hydraulic cylinder 7 is higher than the rodless cavity pressure, the variable speed oil-immersed motor 1 drives the plunger pump 2 to suck oil from the pressure compensator 3 through the oil inlet, the hydraulic oil flowing out of the oil outlet of the plunger pump 2 flows to the oil paths a1 and a2 through the oil path a respectively, the hydraulic oil in the oil path a1 flows to the check valve of the first balance valve 5.1, and generates control pressure in the control oil path of the overflow valve of the second balance valve 5.2, so that the overflow valve of the second balance valve 5.2 is bidirectionally conducted. The hydraulic oil in the oil path a1 flows out of the check valve of the first balance valve 5.1, and flows to the oil paths c1 and c2 through the oil path c respectively, the oil path c2 is connected with the first overflow valve 6.1 to realize the control of the oil pressure, and the oil path c1 is connected with the rod cavity of the asymmetric hydraulic cylinder 7, at this time, the rod cavity is a high-pressure cavity for realizing the movement control of the actuator. The hydraulic oil in the rodless cavity flows to the oil paths d and d2 through the oil path d1 respectively, and the oil path d2 is connected with the second overflow valve 6.2 to realize the control of the oil pressure. If the pressure of the hydraulic oil in the oil path c2 or the oil path d2 is too high, the corresponding first overflow valve 6.1 or the second overflow valve 6.2 will be in the overflow state, and the overflow hydraulic oil flows back to the pressure compensator 3 through the oil paths e and f1. The oil path d is connected with the second balance valve 5.2, the hydraulic oil flows to the oil path b1 through the overflow valve of the second balance valve 5.2, and flows to the oil paths b and b2 respectively, and the hydraulic oil in the oil path b returns to the oil inlet of the plunger pump 2. The hydraulic oil in the oil path a2 flows to the A port of the flow matching valve 4, and generates high control pressure in the control oil path of the C1 port of the flow matching valve 4, the hydraulic oil in the oil path b2 flows to the B port of the flow matching valve 4, and generates low control pressure in the control oil path of the C2 port of the flow matching valve 4, the A port of the flow matching valve 4 is closed, and the B port and the T port of the flow matching valve 4 are conducted. Because the piston areas of the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder 7 are different, when the piston rod retracts, the hydraulic oil flowing out of the rodless cavity is more than the hydraulic oil flowing into the rod cavity, the excess hydraulic oil in the rodless cavity flows to the oil path f1 through the oil path b2 and the B and T ports of the flow matching valve 4, and finally returns to the pressure compensator 3, so as to realize the compensation of the unmatched flow.

[0067] When the asymmetric hydraulic cylinder 7 retracts the piston rod, the external load force acting on the piston rod is in the same direction as the movement direction of the piston rod, and the pressure in the rod cavity of the asymmetric hydraulic cylinder 7 is lower than the pressure in the rodless cavity. The variable-speed oil-immersed motor 1 drives the plunger pump 2 to suck oil from the pressure compensator 3 through the oil suction port. The hydraulic oil flowing out of the oil outlet of the plunger pump 2 flows to the oil paths a1 and a2 through the oil path a, respectively. The hydraulic oil in the oil path a1 flows to the one-way valve of the first balance valve 5.1 and generates a control pressure at the control port of the overflow valve of the second balance valve 5.2 through the control oil path, so that the overflow valve of the second balance valve 5.2 is bidirectionally conducted. The hydraulic oil in the oil path a1 flows out of the one-way valve of the first balance valve 5.1 and flows to the oil paths c1 and c2 through the oil path c, respectively. The oil path c2 is connected to the first overflow valve 6.1 to control the oil pressure, and the oil path c1 is connected to the rod cavity of the asymmetric hydraulic cylinder 7. At this time, the rodless cavity is a high-pressure cavity for realizing the movement control of the actuator, and the hydraulic oil therein flows to the oil paths d and d2 through the oil path d1, respectively. The oil path d2 is connected to the second overflow valve 6.2 to control the oil pressure. If the pressure of the hydraulic oil in the oil path c2 or the oil path d2 is too high, the corresponding first overflow valve 6.1 or second overflow valve 6.2 will be in an overflow state, and the overflow hydraulic oil will flow back to the pressure compensator 3 through the oil paths e and f1. The oil path d is connected to the second balance valve 5.2, and the hydraulic oil flows to the oil path b1 through the overflow valve of the second balance valve 5.2, and flows to the oil paths b and b2, respectively. The hydraulic oil in the oil path b returns to the oil inlet of the plunger pump 2. The hydraulic oil in the oil path a2 flows to the A port of the flow matching valve 4, and generates a low control pressure at the C1 port of the flow matching valve 4 through the control oil path. The hydraulic oil in the oil path b2 flows to the B port of the flow matching valve 4, and generates a high control pressure at the C2 port of the flow matching valve 4 through the control oil path. The B port of the flow matching valve 4 is closed, and the A port and the T port of the flow matching valve 4 are conducted. Since the external load force acting on the piston rod of the asymmetric hydraulic cylinder 7 is in the same direction as the movement direction of the piston rod, in order to avoid the piston rod retracting too fast, part of the hydraulic oil in the oil path a flows to the oil path f1 through the oil path a2 and the A port and the T port of the flow matching valve 4, and finally returns to the pressure compensator 3, realizing the compensation of the unmatched flow and avoiding the rod cavity from being sucked.

[0068] Under resistance extension conditions, the piston rod of the asymmetric hydraulic cylinder 7 extends. The direction of the external load force on the piston rod is opposite to the direction of piston rod movement. The pressure in the rod chamber of the asymmetric hydraulic cylinder 7 is lower than the pressure in the rodless chamber. The variable speed immersion motor 1 drives the plunger pump 2 to draw oil from the pressure compensator 3 through the suction port. The hydraulic oil flowing out of the outlet of the plunger pump 2 flows through oil circuit b to oil circuits b1 and b2 respectively. The hydraulic oil in oil circuit b1 flows to the check valve of the second balance valve 5.2, and generates control pressure through the control oil circuit at the overflow valve control port of the first balance valve 5.1, making the overflow valve of the first balance valve 5.1 bidirectionally open. The hydraulic oil in oil circuit b1 flows out from the check valve of the second balance valve 5.2, and flows through oil circuit d to oil circuits d1 and d2 respectively. Oil circuit d2 is connected to the second overflow valve 6.2 to realize the control of oil pressure. Oil circuit d1 is connected to the rodless chamber of the asymmetric hydraulic cylinder 7. At this time, the rodless chamber is a high-pressure chamber used to realize the motion control of the actuator. Hydraulic oil in the rod chamber flows through oil circuit c1 to oil circuits c and c2 respectively. Oil circuit c2 is connected to the first relief valve 6.1 to control the oil pressure. If the pressure of the hydraulic oil in oil circuit c2 or oil circuit d2 is too high, the corresponding first relief valve 6.1 or second relief valve 6.2 will be in the relief state, and the overflowed hydraulic oil flows back to the pressure compensator through oil circuit e and oil circuit f1. Oil circuit c is connected to the first balance valve 5.1. The hydraulic oil flows through the relief valve of the first balance valve 5.1 to oil circuit a1, and then to oil circuits a and a2 respectively. The hydraulic oil in oil circuit a returns to the inlet of the plunger pump 2. Hydraulic oil in oil circuit a2 flows to port A of flow matching valve 4, and generates a low control pressure at port C1 of flow matching valve 4 via the control oil circuit. Hydraulic oil in oil circuit b2 flows to port B of flow matching valve 4, and generates a high control pressure at port C2 of flow matching valve 4 via the control oil circuit. Port B of flow matching valve 4 is closed, and ports A and T of flow matching valve 4 are open. Because the piston areas of the rod chamber and rodless chamber of asymmetric hydraulic cylinder 7 are different, when the piston rod extends, the amount of hydraulic oil flowing into the rodless chamber is more than the amount flowing out of the rod chamber. Part of the hydraulic oil in pressure compensator 3 flows to oil circuit a2 via oil circuit f1 and ports A and T of flow matching valve 4, and finally flows into the inlet of piston pump 2, thus achieving compensation for the mismatched flow.

[0069] In the over-reach working condition, the piston rod of the asymmetric hydraulic cylinder 7 is extended, the direction of the external load force received by the piston rod is the same as the direction of the piston rod movement, and the pressure in the rod cavity of the asymmetric hydraulic cylinder 7 is higher than the pressure in the rodless cavity. The variable-speed oil-immersed motor 1 drives the plunger pump 2 to suck oil from the pressure compensator 3 through the oil suction port, and the hydraulic oil flowing out of the oil outlet of the plunger pump 2 flows to the oil paths b1 and b2 through the oil path b, respectively. The hydraulic oil in the oil path b1 flows to the one-way valve of the second balance valve 5.2, and generates a control pressure in the control oil path at the overflow valve control port of the first balance valve 5.1, so that the overflow valve of the first balance valve 5.1 is bidirectionally conducted. The hydraulic oil in the oil path b1 flows out of the one-way valve of the second balance valve 5.2, and flows to the oil paths d1 and d2 through the oil path d, respectively. The oil path d2 is connected to the second overflow valve 6.2 to control the oil pressure, and the oil path d1 is connected to the rodless cavity of the asymmetric hydraulic cylinder 7. At this time, the rodless cavity is a high-pressure cavity for realizing the movement control of the actuator. The hydraulic oil in the rod cavity flows to the oil paths c and c2 through the oil path c1, and the oil path c2 is connected to the first overflow valve 6.1 to control the oil pressure. If the pressure of the hydraulic oil in the oil path c2 or the oil path d2 is too high, the corresponding first overflow valve 6.1 or second overflow valve 6.2 will be in an overflow state, and the overflow hydraulic oil will flow back to the pressure compensator 3 through the oil paths e and f1. The oil path c is connected to the first balance valve 5.1, and the hydraulic oil flows to the oil path a1 through the overflow valve of the first balance valve 5.1, and flows to the oil paths a and a2, respectively. The hydraulic oil in the oil path a flows back to the oil inlet of the plunger pump 2. The hydraulic oil in the oil path a2 flows to the A port of the flow matching valve 4, and generates a high control pressure in the control oil path at the C1 port of the flow matching valve 4. The hydraulic oil in the oil path b2 flows to the B port of the flow matching valve 4, and generates a low control pressure in the control oil path at the C2 port of the flow matching valve 4. The A port of the flow matching valve 4 is closed, and the B port and the T port of the flow matching valve 4 are conducted. Since the direction of the external load force received by the piston rod of the asymmetric hydraulic cylinder 7 is the same as the direction of the piston rod movement, in order to avoid the piston rod from extending too fast and causing the oil in the rodless cavity to be too little, part of the hydraulic oil in the pressure compensator 3 flows to the oil path b2 through the oil path f1 and the B and T ports of the flow matching valve 4, and finally flows into the rodless cavity of the asymmetric hydraulic cylinder 7, realizing the compensation of the unmatched flow and avoiding the formation of air suction due to the instantaneous low pressure in the rodless cavity.

[0070] The control system of the application controls the variable speed oil-immersed motor 1, drives the plunger pump 2 to control the flow of hydraulic oil to the asymmetric hydraulic cylinder 7, and realizes the four working conditions of the asymmetric hydraulic cylinder 7. The specific hydraulic circuit mainly includes a flow matching circuit, a hydraulic lock circuit and an overflow circuit. In the flow matching circuit, the unmatched flow generated during the extension and retraction of the asymmetric hydraulic cylinder 7 is adjusted by the flow matching valve 4. The hydraulic lock circuit realizes the position locking function of the asymmetric hydraulic cylinder 7 through two balance valves 5.1 and 5.2. The overflow circuit limits the maximum pressure in the system through two overflow valves 6.1 and 6.2 for safety protection. In the working state, the pressure compensation module completes the balance between the system oil pressure and the external seawater pressure, and at the same time acts as an oil tank to supply oil to the plunger pump 2 through the flow channel.

[0071] In the specific implementation of the application, the deep-sea underwater electro-hydraulic actuator system is placed in a deep-sea environment of 3000 meters, the environmental pressure is 30 MPa, the environmental temperature is 1.5℃, the upper computer sends a motion control instruction to the control system, and the data of the displacement sensor 12 is read in real time. The deep-sea underwater electro-hydraulic actuator executes the expected trajectory as shown in (a) of Figure 10 , the actual trajectory read by the displacement sensor 12 is as shown in (b) of Figure 10 , the trajectory tracking error of the deep-sea underwater electro-hydraulic actuator is the difference between the expected trajectory and the actual trajectory, as shown in (c) of Figure 10 , and the trajectory tracking error is within 1 millimeter. It can be seen that the application can realize high-precision motion control in a deep-sea environment and has good underwater working performance.

[0072] The above is only one embodiment of the application and cannot limit the scope of the application. Equivalent changes made within the scope of the application are still within the protection scope of the application.

Claims

1. A deep-sea subsea electro-hydraulic actuator (EHA) system, characterized in that, include: The power source module is used to provide power to the control system. The pressure compensation module is connected to the power source module and is used to control the pressure balance between the system oil pressure and the external seawater. The pressure compensation module also serves as the oil tank for the control system. An integrated valve module is installed between and connects the power source module and the pressure compensation module. The integrated valve module includes two balance valves and two relief valves for oil pressure control. An actuator module is mounted on and connected to the integrated valve manifold module. The actuator module includes an asymmetric hydraulic cylinder. The control module is installed on the power source module and the asymmetric hydraulic cylinder and is used for the coordinated control of the asymmetric hydraulic cylinder of the power source module, the pressure compensation module and the actuator module; The integrated valve module further includes a flow matching valve and an integrated valve block. The integrated valve block is installed between the power source module and the pressure compensation module. Two balancing valves are installed alternately on one side of the integrated valve block and located inside the power source module. The flow matching valve and two overflow valves are installed alternately on the other side of the integrated valve block and located inside the pressure compensation module. The power source module includes a variable speed oil-immersed motor, a plunger pump, and a power source housing. The power source housing is installed on one side of the integrated valve block where the two balancing valves are located. The two balancing valves are located inside the power source housing. The variable speed oil-immersed motor and the plunger pump are installed inside the power source housing. The output shaft of the variable speed oil-immersed motor is connected to the output shaft of the plunger pump through a coupling. The pump body of the plunger pump is installed at the center of one side of the integrated valve block where the two balancing valves are located and is arranged alternately with the two balancing valves. The pressure compensator's body is mounted on the other side of the integrated valve block containing the flow matching valve and two relief valves. The flow matching valve and two relief valves are located in the hydraulic oil filled inside the pressure compensator, which serves as the oil tank for the control system to supply oil. The control module includes a displacement sensor, a composite transmission cable assembly, an oil-immersed sealed chamber, a main controller, and a motor driver. The oil-immersed sealed chamber is installed on the power source housing, and the main controller and motor driver are installed inside the oil-immersed sealed chamber. When designing and machining right-angled flow channels in the integrated valve block, shorten the length of the tool tip cavity and make the tool tip cavity face the oil inlet. When designing and machining Z-shaped flow channels in the integrated valve block, shorten the distance between the two flow channels. At the same time, increase the diameter of the process hole without affecting the minimum wall thickness of the integrated valve block. The displacement sensor is mounted on the piston rod of the asymmetric hydraulic cylinder; the composite transmission cable includes a DC cable and a second bus communication cable that electrically connect the displacement sensor and the motor driver, and the main controller is electrically connected to an external host computer through the first bus communication cable; the DC cable provides DC power to the main controller and the motor driver respectively; the oil-immersed sealed chamber is connected to a pressure compensation module, and the motor driver is electrically connected to a variable speed oil-immersed motor. The main controller is internally integrated with a trajectory planning algorithm, a state observation algorithm and a position control algorithm; the host computer sends control instructions to the main controller through a first bus communication cable; the main controller receives the running state of the asymmetric hydraulic cylinder obtained by the displacement sensor and the running state of the variable-speed immersed oil motor obtained by the motor driver through a second bus communication cable; the main controller obtains an expected trajectory according to a preset trajectory instruction and through processing by the trajectory planning algorithm; the running state of the variable-speed immersed oil motor and the asymmetric hydraulic cylinder and the expected trajectory are processed by the state observation algorithm to obtain the pressure values of the two cavities of the asymmetric hydraulic cylinder and the external load force; the pressure values of the two cavities of the asymmetric hydraulic cylinder and the external load force are processed by the position control algorithm to obtain the expected speed of the variable-speed immersed oil motor; the expected speed of the variable-speed immersed oil motor is transmitted to the variable-speed immersed oil motor for speed control through pulse width modulation (PWM) modulation by the motor driver; after the control is completed, the main controller transmits the real-time running state of the variable-speed immersed oil motor and the asymmetric hydraulic cylinder to the host computer for display and real-time state monitoring. The actuator module further comprises a connecting piece, which comprises a sub-valve block and two steel pipes; the cylinder body of the asymmetric hydraulic cylinder is installed on the side of the integrated valve block through the sub-valve block; the two steel pipes are installed on the cylinder body of the asymmetric hydraulic cylinder and respectively communicate the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder with the ninth flow channel c1 and the eleventh flow channel d1 inside the integrated valve block.

2. A deep ocean subsea electro-hydraulic actuator (EHA) system as claimed in claim 1, characterized by: The oil outlet and the oil inlet of the plunger pump respectively communicate the first flow channel a and the second flow channel b inside the integrated valve block; the first flow channel a is divided into the third flow channel a1 and the fourth flow channel a2; the second flow channel b is divided into the fifth flow channel b1 and the sixth flow channel b2; the third flow channel a1, the oil outlet of the overflow valve of the first balance valve and the oil inlet of the one-way valve are communicated; the fourth flow channel a2, the A port and the C1 port of the flow matching valve are communicated; the fifth flow channel b1, the oil outlet of the overflow valve of the second balance valve and the oil inlet of the one-way valve are communicated; the sixth flow channel b2, the B port and the C2 port of the flow matching valve are communicated; the oil inlet of the overflow valve of the first balance valve and the oil outlet of the one-way valve are communicated with the seventh flow channel c inside the integrated valve block; the oil outlet of the overflow valve of the second balance valve and the oil inlet of the one-way valve are communicated with the eighth flow channel d inside the integrated valve block; the seventh flow channel c is divided into the ninth flow channel c1 and the tenth flow channel c2; the eighth flow channel d is divided into the eleventh flow channel d1 and the twelfth flow channel d2; the ninth flow channel c1 and the eleventh flow channel d1 respectively communicate the rod cavity and the rodless cavity of the asymmetric hydraulic cylinder of the actuator module; the tenth flow channel c2 communicates the oil inlet of the first overflow valve; the twelfth flow channel d2 communicates the oil inlet of the second overflow valve; the oil outlets of the two overflow valves are connected and communicated with the T port of the flow matching valve through the thirteenth flow channel e inside the integrated valve block; the pressure compensation module is respectively communicated with the T port of the flow matching valve and the oil supplement port of the plunger pump through the fourteenth flow channel f1 and the fifteenth flow channel f2 inside the integrated valve block; the control module is installed on the power source shell; the control module is electrically connected with the variable-speed immersed oil motor and the asymmetric hydraulic cylinder.

3. A deep ocean subsea electro-hydraulic actuator (EHA) system as claimed in claim 2, characterized by: The pressure compensation module adopts a bladder type pressure compensator.

4. The deep-sea subsea electro-hydraulic actuator (EHA) system of claim 2, wherein: The control system drives the plunger pump by the variable speed oil-immersed motor, controls the hydraulic oil flow direction of the asymmetric hydraulic cylinder, and realizes four working conditions of the asymmetric hydraulic cylinder, including resistance retracting condition, overrun retracting condition, resistance extending condition and overrun extending condition.

5. A deep ocean subsea electro-hydraulic actuator (EHA) system as claimed in claim 4, characterized by: In the resistance retracting condition, the pressure of the rod cavity of the asymmetric hydraulic cylinder is higher than that of the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the first balance valve, and the control pressure is generated at the overflow valve of the second balance valve, so that the overflow valve of the second balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the first balance valve flows into the rod cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the first overflow valve, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder is controlled through the second overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the second balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the A port of the flow matching valve, and high control pressure is generated at the C1 port of the flow matching valve, the hydraulic oil flowing out of the rodless cavity of the asymmetric hydraulic cylinder flows to the B port of the flow matching valve, and low control pressure is generated at the C2 port of the flow matching valve, so that the A port of the flow matching valve is closed and the B port and the T port are open, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder returns to the pressure compensator through the B port and the T port of the flow matching valve, and the compensation of unmatched flow is realized.

6. The deep-sea subsea electro-hydraulic actuator (EHA) system of claim 4, wherein: In the resistance retracting condition, the pressure of the rod cavity of the asymmetric hydraulic cylinder is higher than that of the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the first balance valve, and the control pressure is generated at the overflow valve of the second balance valve, so that the overflow valve of the second balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the first balance valve flows into the rod cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the first overflow valve, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder is controlled through the second overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rodless cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the second balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the A port of the flow matching valve, and low control pressure is generated at the C1 port of the flow matching valve, the hydraulic oil flowing out of the rodless cavity flows to the B port of the flow matching valve, and high control pressure is generated at the C2 port of the flow matching valve, so that the B port of the flow matching valve is closed and the A port and the T port are open, the hydraulic oil at the oil outlet of the plunger pump returns to the pressure compensator through the A port and the T port of the flow matching valve, and the compensation of unmatched flow is realized.

7. The deep-sea subsea electro-hydraulic actuator (EHA) system of claim 4, wherein: In the resistance extension working condition, the pressure in the rod cavity of the asymmetric hydraulic cylinder is lower than the pressure in the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the second balance valve, and the control pressure is generated at the overflow valve of the first balance valve, so that the overflow valve of the first balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the second balance valve flows into the rodless cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the second overflow valve, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder is controlled through the first overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the first balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the B port of the flow matching valve, and high control pressure is generated at the C2 port of the flow matching valve, the hydraulic oil flowing out of the rod cavity of the asymmetric hydraulic cylinder flows to the A port of the flow matching valve, and low control pressure is generated at the C1 port of the flow matching valve, so that the B port of the flow matching valve is closed and the A port and the T port are open, and the hydraulic oil in the pressure compensator flows into the oil inlet of the plunger pump through the A port and the T port of the flow matching valve, so as to compensate for the unmatched flow.

8. The deep-sea subsea electro-hydraulic actuator (EHA) system of claim 4, wherein: In the resistance extension working condition, the pressure in the rod cavity of the asymmetric hydraulic cylinder is lower than the pressure in the rodless cavity, the variable speed oil-immersed motor drives the plunger pump to suck oil from the pressure compensator through the oil suction port, the hydraulic oil flowing out of the oil outlet of the plunger pump flows to the one-way valve of the second balance valve, and the control pressure is generated at the overflow valve control port of the first balance valve, so that the overflow valve of the first balance valve is bidirectional, the hydraulic oil flowing out of the one-way valve of the second balance valve flows into the rodless cavity of the asymmetric hydraulic cylinder, and the oil pressure is controlled through the second overflow valve, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder is controlled through the first overflow valve, the hydraulic oil overflowing through the first overflow valve or the second overflow valve flows back to the pressure compensator, the hydraulic oil in the rod cavity of the asymmetric hydraulic cylinder returns to the oil inlet of the plunger pump through the overflow valve of the first balance valve, at the same time, the hydraulic oil at the oil outlet of the plunger pump flows to the B port of the flow matching valve, and low control pressure is generated at the C2 port of the flow matching valve, the hydraulic oil flowing out of the rod cavity of the asymmetric hydraulic cylinder flows to the A port of the flow matching valve, and high control pressure is generated at the C1 port of the flow matching valve, so that the A port of the flow matching valve is closed and the B port and the T port are open, and the hydraulic oil in the pressure compensator flows into the rodless cavity of the asymmetric hydraulic cylinder through the B port and the T port of the flow matching valve, so as to compensate for the unmatched flow.

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