Hydraulic propeller control system of underwater cable laying robot

Abstract

The utility model discloses a hydraulic thruster control system of an underwater cable laying robot, the system is a closed control system, the system comprises a closed pump, a main system, a thruster control valve group, a motor, a control oil source and an oil tank, two oil ports of the closed pump are respectively connected with the main system, the thruster control valve group is provided with oil ports, the oil ports comprise C1, C2, C3, C4, C5, C6, C7 and C8, and the motor is connected with the control oil source. One oil port of the closed pump is connected with the C1, the other oil port of the closed pump is connected with the C2, the propeller control valve set comprises a hydraulic valve V1, a hydraulic valve V2, a hydraulic valve V3 and a hydraulic valve V4, the hydraulic valve V1 is connected with the hydraulic valve V2 in parallel, and the hydraulic valve V3 is connected with the hydraulic valve V4 in parallel. The device can meet the requirements of various construction operation environments of the underwater operation robot, and is stable, reliable, simple and effective.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic thruster control of underwater cable-laying robots, and specifically relates to a hydraulic thruster control system for underwater cable-laying robots. Background Technique

[0002] An underwater cable-laying robot is a robot used for cable laying and maintenance in an underwater environment. It can perform various tasks underwater, such as installing submarine cables, repairing damaged cables, etc. When an underwater trench-digging and cable-laying robot operates underwater, actions such as turning and flying are all completed by hydraulic thrusters. Also, due to the non-uniqueness of wind farms, each construction environment is different, and the size and quantity of the required thrusters also vary, so as to ensure that the underwater trench-digging and cable-laying robot can adapt to the construction environment. The existing control method of the thruster control system is single and difficult to meet the requirements of various construction operation environments. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the above-mentioned shortcomings of the existing technology and provide a hydraulic thruster control system for underwater cable-laying robots that can meet the requirements of various construction operation environments of underwater operation robots, is stable and reliable, and is simple and effective.

[0004] The utility model is realized through the following technical solutions: A hydraulic thruster control system for an underwater cable-laying robot, the system is a closed-loop control system, and it includes a closed-loop pump, a main system, a thruster control valve group, a motor, a control oil source, and an oil tank.

[0005] Two oil ports of the closed-loop pump are respectively connected to the main system.

[0006] An oil port is arranged on the thruster control valve group, and the oil port includes C1, C2, C3, C4, C5, C6, C7, and C8. One oil port of the closed-loop pump is connected to C1, and the other oil port of the closed-loop pump is connected to C2.

[0007] The thruster control valve group includes hydraulic valve V1, hydraulic valve V2, hydraulic valve V3, and hydraulic valve V4, and the hydraulic valve V1 is connected in parallel with the hydraulic valve V2, and the hydraulic valve V3 is connected in parallel with the hydraulic valve V4.

[0008] Port 1 of the hydraulic valve V1 is connected to C6, C6 is connected to port A of the motor, port 2 of the hydraulic valve V1 is connected to C2, port 3 of the hydraulic valve V1 is connected to C8, and C8 is connected to the control oil source.

[0009] Port 1 of the hydraulic valve V2 is connected to C3, C3 is connected to port B of the motor, and port 2 of the hydraulic valve V2 is connected to C1.

[0010] Port 1 of the hydraulic valve V3 is connected to C4. C4 is connected to the pipeline between port A of the motor and C6. Port 2 of the hydraulic valve V3 is connected to C1.

[0011] Port 1 of the hydraulic valve V4 is connected to C5. C5 is connected to the pipeline between port B of the motor and C3. Port 2 of the hydraulic valve V4 is connected to C2.

[0012] Port 4 of the hydraulic valve V1, port 4 of the hydraulic valve V2, port 4 of the hydraulic valve V3, and port 4 of the hydraulic valve V4 are respectively connected to C7. C7 is connected to the fuel tank.

[0013] Further: The motor is connected to the thruster through a connecting shaft. The connecting shaft has a sealed cavity. The sealed cavity is connected to a compensator. The compensator is respectively connected to the two oil ports of the closed pump.

[0014] A hydraulic thruster control system for an underwater cable-laying robot. The system is an open control system and includes a variable pump, an HCU control valve box, a thruster control valve block, and a motor I.

[0015] The thruster control valve block is provided with oil ports, and the oil ports include C1, C2, C3, C4, C5, C6, and C7.

[0016] The thruster control valve block includes a fixed-differential pressure reducing valve, a proportional hydraulically controlled directional valve, and a shuttle valve. Port 1 of the proportional hydraulically controlled directional valve is connected to C5. Port 2 of the proportional hydraulically controlled directional valve is connected to C4. C4 is connected to port A of the motor I. Port 3 of the proportional hydraulically controlled directional valve is connected to the outlet 7.1 of the fixed-differential pressure reducing valve. The inlet 7.2 of the fixed-differential pressure reducing valve is connected to C1. C1 is connected to the output end of the variable pump. Port 4 of the proportional hydraulically controlled directional valve is connected to C3. C3 is connected to port B of the motor I. Port 5 of the proportional hydraulically controlled directional valve is connected to C2. Port 6 of the proportional hydraulically controlled directional valve is connected to C6. The spring chamber pressure oil port 7.3 of the fixed-differential pressure reducing valve is connected to the output port 9.3 of the shuttle valve. The selection oil port 9.1 of the shuttle valve is connected to C3. The selection oil port 9.2 of the shuttle valve is connected to C4.

[0017] The HCU control valve box internally includes a thruster control valve, other control modules, and a standby module.

[0018] The thruster control valve is provided with oil ports, and the oil ports include D1, D2, D3, and D4. D1 is connected to C5. D2 is connected to C6. D3 is connected to the output end of the variable pump.

[0019] The propeller control valve includes a pilot proportional directional valve and a pilot proportional relief valve. Port 1 of the pilot proportional directional valve is connected to D1, port 2 of the pilot proportional directional valve is connected to D2, ports 3 and 4 of the pilot proportional directional valve are respectively connected to the pilot proportional relief valve, port 3 of the pilot proportional directional valve is connected to D4, and port 4 of the pilot proportional directional valve is connected to D3.

[0020] Further: The output end of the variable pump is connected to a high-pressure filter, a check valve is connected between the high-pressure filter and the variable pump, and a safety valve is connected between the high-pressure filter and the check valve.

[0021] Further: It also includes an engineering response valve block and a motor II. The engineering response valve block is connected to the standby module, the engineering response valve block is connected to the output end of the variable pump, and ports A and B of the motor II are respectively connected to the engineering response valve block.

[0022] Further: The motor I is connected to a propeller I through a connecting shaft I, the motor II is connected to a propeller II through a connecting shaft II, both the connecting shaft I and the connecting shaft II have sealed cavities, and a compensator is connected between the sealed cavity of the connecting shaft I and the sealed cavity of the connecting shaft II.

[0023] Further: The engineering response valve block is provided with oil ports, and the oil ports include C1, C2, C3, C4, C5, C6, C7, and C8.

[0024] The engineering response valve block includes a proportional relief valve I, a proportional relief valve II, a proportional pilot-operated directional valve, a fixed-differential pressure reducing valve, and a shuttle valve.

[0025] Port 1 of the proportional pilot-operated directional valve is connected to C5, port 2 of the proportional pilot-operated directional valve is connected to C4, C4 is connected to port A of the motor II, port 3 of the proportional pilot-operated directional valve is connected to port 1 of the fixed-differential pressure reducing valve, port 4 of the proportional pilot-operated directional valve is connected to C3, C3 is connected to port B of the motor II, port 5 of the proportional pilot-operated directional valve is connected to C2, port 6 of the proportional pilot-operated directional valve is connected to C6, and C5 and C6 are respectively connected to the standby module.

[0026] Port 1 of the proportional pilot-operated directional valve is connected to the inlet port of the proportional relief valve I, port 6 of the proportional pilot-operated directional valve is connected to the inlet port of the proportional relief valve II, and the outlet ports of the proportional relief valve I and the proportional relief valve II are connected to C8.

[0027] Port 2 of the fixed differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 3 of the fixed differential pressure reducing valve is connected to the output port 3 of the shuttle valve, the output port 3 of the shuttle valve is connected to C7, the selection port 1 of the shuttle valve is connected to C3, and the selection port 2 of the shuttle valve is connected to C4.

[0028] Furthermore, oil ports are provided on the engineering response valve block, and the oil ports include C1, C2, C3, C4, C5, C6, C7, and C8.

[0029] The engineering response valve block includes a direct-acting pressure reducing valve I, a direct-acting pressure reducing valve II, a proportional pressure reducing valve I, a proportional pressure reducing valve II, a fixed differential pressure reducing valve, a proportional pilot-operated directional valve, and a shuttle valve.

[0030] Port 1 of the proportional pilot-operated directional valve is connected to C5, port 2 of the proportional pilot-operated directional valve is connected to C4, C4 is connected to port A of the motor II, port 3 of the proportional pilot-operated directional valve is connected to port 1 of the fixed differential pressure reducing valve, port 4 of the proportional pilot-operated directional valve is connected to C3, C3 is connected to port B of the motor II, port 5 of the proportional pilot-operated directional valve is connected to C2, port 6 of the proportional pilot-operated directional valve is connected to C6, and C5 and C6 are respectively connected to the standby module.

[0031] The direct-acting pressure reducing valve I and the proportional pressure reducing valve I are connected in series, and the direct-acting pressure reducing valve I is connected to C5, the proportional pressure reducing valve I is connected to port 1 of the proportional pilot-operated directional valve, the direct-acting pressure reducing valve I and the proportional pressure reducing valve I are respectively connected to C8, the direct-acting pressure reducing valve II and the proportional pressure reducing valve II are connected in series, and the direct-acting pressure reducing valve II is connected to C6, the proportional pressure reducing valve II is connected to port 6 of the proportional pilot-operated directional valve, and the direct-acting pressure reducing valve II and the proportional pressure reducing valve II are respectively connected to C8.

[0032] Port 2 of the fixed differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 3 of the fixed differential pressure reducing valve is connected to the output port 3 of the shuttle valve, the output port 3 of the shuttle valve is connected to C7, the selection port 1 of the shuttle valve is connected to C3, and the selection port 2 of the shuttle valve is connected to C4.

[0033] Furthermore, oil ports are provided on the engineering response valve block, and the oil ports include C1, C2, C3, C4, C5, C6, C7, and C8.

[0034] The engineering response valve block includes a direct-acting pressure reducing valve, a proportional pressure reducing valve I, a proportional pressure reducing valve II, a fixed differential pressure reducing valve, a proportional pilot-operated directional valve, and a shuttle valve.

[0035] Port 1 of the proportional hydraulically controlled directional valve is connected to the oil outlet of the proportional pressure reducing valve II. Port 2 of the proportional hydraulically controlled directional valve is connected to C4, and C4 is connected to port A of the motor II. Port 3 of the proportional hydraulically controlled directional valve is connected to port 1 of the differential pressure reducing valve. Port 4 of the proportional hydraulically controlled directional valve is connected to C3, and C3 is connected to port B of the motor II. Port 5 of the proportional hydraulically controlled directional valve is connected to C2. Port 6 of the proportional hydraulically controlled directional valve is connected to C6. C5 and C6 are respectively connected to the standby module.

[0036] The inlet port of the direct-acting pressure reducing valve is connected to C6. The outlet port of the direct-acting pressure reducing valve is connected to the inlet port of the proportional pressure reducing valve I. The outlet port of the proportional pressure reducing valve I is connected to port 6 of the proportional hydraulically controlled directional valve. The inlet port of the proportional pressure reducing valve II is connected between the outlet port of the direct-acting pressure reducing valve and the inlet port of the proportional pressure reducing valve I. The direct-acting pressure reducing valve, the proportional pressure reducing valve I, and the proportional pressure reducing valve II are respectively connected to C8.

[0037] Port 2 of the differential pressure reducing valve is connected to C1, and C1 is connected to the output end of the variable pump. Port 3 of the differential pressure reducing valve is connected to output port 3 of the shuttle valve. Output port 3 of the shuttle valve is connected to C7. Selection port 1 of the shuttle valve is connected to C3. Selection port 2 of the shuttle valve is connected to C4.

[0038] Compared with the prior art, the utility model has the following beneficial effects:

[0039] 1. The control system of the utility model is divided into a closed control system and an open control system, with multiple control methods, which can adapt to the differences in each construction condition of the underwater trenching and cable-laying robot and meet the requirements of the multi-construction operation environment of the underwater operation robot.

[0040] 2. The open control system of the utility model adopts a control method of using a pilot proportional directional valve to control the commutation of the proportional hydraulically controlled directional valve, avoiding the influence of the change of the driving motor characteristics on the thruster control and improving the control accuracy of the thruster.

[0041] 3. The open control system of the utility model ensures that when a single pump drives multiple thrusters, the rotational speeds of each thruster are not affected by the load and always maintain the set rotational speed by setting a shuttle valve and a differential pressure reducing valve.

[0042] 4. The control system of the utility model eliminates the influence of the seawater pressure on the shaft between the thruster and the motor by setting a sealed cavity between the motor and the thruster connecting shaft body and performing pressure compensation, which can further improve the efficiency and stability of the thruster.

[0043] 5. In the open control system of the present utility model, multiple engineering response valve block solutions are set, which can efficiently and stably adapt to the applicability changes of the addition and subtraction of thrusters in multiple projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of the first embodiment of the present utility model;

[0045] Figure 2 It is a schematic structural diagram of the second embodiment of the present utility model;

[0046] Figure 3 It is a schematic structural diagram of the third embodiment of the present utility model;

[0047] Figure 4 It is a schematic structural diagram of the fourth embodiment of the present utility model;

[0048] Figure 5 It is a schematic structural diagram of the fifth embodiment of the present utility model.

[0049] Description of the reference numerals: 1 - closed pump, 2 - main system, 3 - thruster control valve group, 4 - motor, 5 - control oil source, 6 - oil tank, 7 - connecting shaft, 8 - thruster, 9 - compensator, 10 - variable pump, 11 - HCU control valve box, 12 - thruster control valve block, 13 - motor I, 14 - fixed differential pressure reducing valve, 15 - proportional hydraulic control reversing valve, 16 - shuttle valve, 17 - thruster control valve, 18 - other control modules, 19 - standby module, 20 - pilot proportional reversing valve, 21 - pilot proportional overflow valve, 22 - high-pressure filter, 23 - check valve, 24 - safety valve, 25 - engineering response valve block, 26 - motor II, 27 - connecting shaft I, 28 - thruster I, 29 - connecting shaft II, 30 - thruster II, 31 - proportional overflow valve I, 32 - proportional overflow valve II, 33 - direct-acting pressure reducing valve I, 34 - direct-acting pressure reducing valve II, 35 - proportional pressure reducing valve I, 36 - proportional pressure reducing valve II, 37 - direct-acting pressure reducing valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The present utility model will be described below in conjunction with the embodiments

[0051] Embodiment 1

[0052] Refer to Figure 1 , a hydraulic thruster control system for an underwater cable laying robot, the system is a closed control system, which includes a closed pump 1, a main system 2, a thruster control valve group 3, a motor 4, a control oil source 5, and an oil tank 6.

[0053] The two oil ports of the closed pump 1 are respectively connected to the main system 2.

[0054] The thruster control valve group 3 is provided with oil ports, including C1, C2, C3, C4, C5, C6, C7, and C8. One oil port of the closed pump 1 is connected to C1, and the other oil port of the closed pump 1 is connected to C2.

[0055] The thruster control valve group 3 includes hydraulic valves V1, V2, V3, and V4, and the hydraulic valve V1 is connected in parallel with the hydraulic valve V2, and the hydraulic valve V3 is connected in parallel with the hydraulic valve V4.

[0056] Port 1 of the hydraulic valve V1 is connected to C6, C6 is connected to port A of the motor 4, port 2 of the hydraulic valve V1 is connected to C2, port 3 of the hydraulic valve V1 is connected to C8, and C8 is connected to the control oil source 5.

[0057] Port 1 of the hydraulic valve V2 is connected to C3, C3 is connected to port B of the motor 4, and port 2 of the hydraulic valve V2 is connected to C1.

[0058] Port 1 of the hydraulic valve V3 is connected to C4, C4 is connected to the pipeline between port A of the motor 4 and C6, and port 2 of the hydraulic valve V3 is connected to C1.

[0059] Port 1 of the hydraulic valve V4 is connected to C5, C5 is connected to the pipeline between port B of the motor 4 and C3, and port 2 of the hydraulic valve V4 is connected to C2.

[0060] Port 4 of the hydraulic valve V1, port 4 of the hydraulic valve V2, port 4 of the hydraulic valve V3, and port 4 of the hydraulic valve V4 are respectively connected to C7, and C7 is connected to the fuel tank 6.

[0061] The working principle of this embodiment:

[0062] The thruster rotates forward:

[0063] The motor starts, driving the closed pump 1 to start, and the output high-pressure oil enters the thruster control valve group 3. At this time, the control oil source 5 is in the closed state, and there is no output of the control oil source. At this time, the left position of the hydraulic valve V1 and the left position of the hydraulic valve V4 work, and the right position of the hydraulic valve V2 and the right position of the hydraulic valve V3 work; the high-pressure oil enters from the C1 oil port of the thruster control valve group 3, flows out from the C4 oil port of the thruster control valve group 3 after passing through the hydraulic valve V3 and enters port A of the motor 4, drives the motor 4 to rotate and then turns into low-pressure oil and flows out from port B of the motor 4, and returns to the closed pump 1 from the C2 oil port through the hydraulic valve V4 via the C5 oil port of the thruster control valve group 3, completing the drive of the thruster 8.

[0064] The thruster rotates in reverse:

[0065] The motor starts, driving the closed pump 1 to start. The output high-pressure oil enters the thruster control valve group 3. At this time, the control oil source 5 is in the open state, outputting high-pressure control oil. When the pressure of the control oil is greater than the spring pressures set by the hydraulic valves V1, V2, V3, and V4, the hydraulic valves V1, V2, V3, and V4 all change their directions under the action of the control oil source 5. At this time, the right positions of the hydraulic valves V1 and V4 work, and the left positions of the hydraulic valves V2 and V3 work. The high-pressure oil enters from C1 of the thruster control valve group 3, flows out from C3 of the thruster control valve group 3 after passing through the hydraulic valve V2, enters port B of the motor 4, drives the motor 4 to rotate, and then turns into low-pressure oil and flows out from port A of the motor 4, returns to the closed pump through C6 of the thruster control valve group 3 and the hydraulic valve V1 from C2, completing the drive of the thruster 8.

[0066] In addition, in this embodiment, the motor 4 is connected to the thruster 8 through a connecting shaft 7. The connecting shaft 7 has a sealed cavity, and the sealed cavity is connected to a compensator 9. The compensator 9 is respectively connected to the two oil ports of the closed pump 1.

[0067] By providing a sealed cavity at the connecting shaft 7 between the motor 4 and the thruster 8 and connecting the sealed cavity to the compensator 9, it is ensured that the internal pressure of the connecting shaft 7 and the external pressure of the seawater always remain within the originally set pressure difference range, so as to eliminate the influence of the seawater pressure on the connecting shaft 7 between the thruster 8 and the motor 4, and the thruster can work more efficiently and stably.

[0068] Embodiment 2

[0069] Refer to Figure 2 , a hydraulic thruster control system for an underwater cable laying robot. The system is an open control system, and it includes a variable pump 10, an HCU control valve box 11, a thruster control valve block 12, and a motor I 13.

[0070] The thruster control valve block 12 is provided with oil ports, and the oil ports include C1, C2, C3, C4, C5, C6, and C7.

[0071] The thruster control valve block 12 includes a constant differential pressure reducing valve 14, a proportional hydraulically controlled directional valve 15, and a shuttle valve 16. Port 1 of the proportional hydraulically controlled directional valve 15 is connected to C5, port 2 of the proportional hydraulically controlled directional valve 15 is connected to C4, C4 is connected to port A of the motor I 13, port 3 of the proportional hydraulically controlled directional valve 15 is connected to the outlet 7.1 of the constant differential pressure reducing valve 14, the inlet 7.2 of the constant differential pressure reducing valve 14 is connected to C1, C1 is connected to the output end of the variable pump 10, port 4 of the proportional hydraulically controlled directional valve 15 is connected to C3, C3 is connected to port B of the motor I 13, port 5 of the proportional hydraulically controlled directional valve 15 is connected to C2, port 6 of the proportional hydraulically controlled directional valve 15 is connected to C6, the pressure oil port 7.3 of the spring chamber of the constant differential pressure reducing valve 14 is connected to the outlet port 9.3 of the shuttle valve 16, the selection oil port 9.1 of the shuttle valve 16 is connected to C3, and the selection oil port 9.2 of the shuttle valve 16 is connected to C4.

[0072] Inside the HCU control valve box 11, there are a thruster control valve 17, other control modules 18, and a standby module 19.

[0073] The thruster control valve 17 is provided with oil ports, including D1, D2, D3, and D4. D1 is connected to C5, D2 is connected to C6, and D3 is connected to the output end of the variable pump 10.

[0074] The thruster control valve 17 includes a pilot proportional directional valve 20 and a pilot proportional relief valve 21. Port 1 of the pilot proportional directional valve 20 is connected to D1, port 2 of the pilot proportional directional valve 20 is connected to D2, ports 3 and 4 of the pilot proportional directional valve 20 are respectively connected to the pilot proportional relief valve 21, port 3 of the pilot proportional relief valve 21 is connected to D4, and port 4 of the pilot proportional relief valve 21 is connected to D3.

[0075] The output end of the variable pump 10 is connected with a high-pressure filter 22. A check valve 23 is connected between the high-pressure filter 22 and the variable pump 10, and a safety valve 24 is connected between the high-pressure filter 22 and the check valve 23.

[0076] The working principle of this embodiment:

[0077] The thruster I rotates forward:

[0078] The motor starts, driving the variable pump 10 to start, outputting high-pressure hydraulic oil which enters the HCU control valve box 11 and the thruster control valve block 12 after passing through the one-way valve 23 and the high-pressure filter 22. When the left position of the pilot proportional directional valve 20 is energized and the left position of the pilot proportional directional valve 20 works, when the high-pressure hydraulic oil is decompressed by the pilot proportional relief valve 21 to within the control pressure range of the proportional pilot-operated directional valve 15, the high-pressure hydraulic oil is output from the right position of the pilot proportional directional valve 20, enters the thruster control valve block 12 from C5, pushes the proportional pilot-operated directional valve 15 to change its position and work in the right position. At the same time, the high-pressure hydraulic oil in the thruster control valve block 12 passes through the fixed-differential pressure reducing valve 14 and enters the right working position of the proportional pilot-operated directional valve 15, then flows into port A of the motor I 13 from port C4 of the thruster control valve block 12, driving the motor I 13 to rotate.

[0079] Reverse rotation of thruster I:

[0080] The motor starts, driving the variable pump 10 to start, outputting high-pressure hydraulic oil which enters the HCU control valve box 11 and the thruster control valve block 12 after passing through the one-way valve 23 and the high-pressure filter 22. When the right position of the pilot proportional directional valve 20 is energized and the right position of the pilot proportional directional valve 20 works, when the high-pressure hydraulic oil is decompressed by the pilot proportional relief valve 21 to within the control pressure range of the proportional pilot-operated directional valve 15, the high-pressure hydraulic oil is output from the right position of the pilot proportional directional valve 20, enters the thruster control valve block 12 from C5, pushes the proportional pilot-operated directional valve 15 to change its position and work in the left position. At the same time, the high-pressure hydraulic oil entering the thruster control valve block 12 passes through the fixed-differential pressure reducing valve 14 and enters the left working position of the proportional pilot-operated directional valve 15, then flows into port B of the motor I 13 from port C3 of the thruster control valve block 12, driving the motor I 13 to rotate.

[0081] In the thruster control loop of the open-loop control system of this embodiment, because the overall system is a single-pump control for multiple actuator actions, when the thruster works in deep sea, due to factors such as ocean currents, there will be inconsistent loads and uneven flow distribution among multiple thrusters, resulting in unstable thruster control. To eliminate this situation, the open-loop system of this embodiment is provided with a pressure compensation loop, specifically as follows:

[0082] A fixed-differential pressure reducing valve 14 and a shuttle valve 16 are set in the control system, and the fixed-differential pressure reducing valve 14 and the shuttle valve 16 are used as pressure compensation elements of the control system. Among them, the fixed-differential pressure reducing valve 14 is set in front of the proportional pilot-operated directional valve 15. The inlet 7.2 of the fixed-differential pressure reducing valve 14 is connected to the high-pressure hydraulic oil output by the variable pump 10, the outlet 7.1 of the fixed-differential pressure reducing valve 14 outputs the flow directly into the proportional pilot-operated directional valve 15, and the pressure oil port of the spring chamber of the fixed-differential pressure reducing valve 14 is connected to the flow output port 9.3 of the shuttle valve 16. The shuttle valve 16 is set behind the proportional pilot-operated directional valve 15 and connects the two flow selection ports 9.1 and 9.2 to port A and port B of the motor I 13 respectively. The specific working principle is as follows:

[0083] Since the thruster operates in seawater and is affected by natural factors such as seawater flow, the load of the thruster varies greatly. To ensure a constant operating speed of the thruster, it is necessary to ensure that the flow rate entering the thruster does not change with the load. According to the orifice flow formula, we have:

[0084]

[0085] In the formula, Q: flow rate;

[0086] C d : flow coefficient of thin-walled orifice;

[0087] A 0 : flow area of the orifice;

[0088] ρ: density of the fluid

[0089] ΔP: pressure difference before and after the orifice.

[0090] The flow coefficient C of the thin-walled orifice in the orifice flow formula d , the flow area A of the orifice 0 , and the density ρ of the fluid are all constants. The only parameter affecting the flow rate Q is the pressure difference ΔP before and after the orifice.

[0091] Therefore, in this solution, the spring pressure of the constant differential pressure reducing valve 14 is set to ΔP, and the two flow selection ports are respectively connected to the flow output ports 9.3 of the shuttle valve 16 at the A and B ports of the motor Ⅰ 13, and the output flow is connected to the inside of the spring chamber of the constant differential pressure reducing valve 14. After this connection method, regardless of whether the thruster rotates forward or backward and how the load changes, the thruster load pressure P can be transmitted to the spring chamber of the constant differential pressure reducing valve 14, and finally feedback to the input pressure P1 at the input port 7.2 of the constant differential pressure reducing valve 14, ensuring that the input pressure P1 is always higher than the thruster load pressure P by a constant differential pressure reducing valve 14 spring setting pressure ΔP. That is, when the opening area of the proportional hydraulic control reversing valve 15 is constant, the pressure P at the front end of the proportional hydraulic control reversing valve 15 is always larger than the pressure P1 at the rear end of the proportional hydraulic control reversing valve 15 by a ΔP, so as to ensure that regardless of how the thruster load condition changes, the flow rate input to the thruster remains constant, and the thruster speed is kept constant at the pre-designed speed.

[0092] Example Three

[0093] Referring to Figure 2 and Figure 3 , the difference between this embodiment and the second embodiment is that this embodiment further includes an engineering response valve block 25 and a motor Ⅱ 26. The engineering response valve block 25 is connected to the standby module 19, the engineering response valve block 25 is connected to the output end of the variable pump 10, and the A and B ports of the motor Ⅱ 26 are respectively connected to the engineering response valve block 25.

[0094] The motor I 13 is connected to the thruster I 28 through the connecting shaft I 27, and the motor II 26 is connected to the thruster II 30 through the connecting shaft II 29. The connecting shaft I 27 and the connecting shaft II 29 both have sealed cavities, and a compensator 9 is connected between the sealed cavity of the connecting shaft I 27 and the sealed cavity of the connecting shaft II 29.

[0095] In this embodiment, the engineering response valve block 25 is provided with oil ports, and the oil ports include C1, C2, C3, C4, C5, C6, C7, and C8.

[0096] The engineering response valve block 25 includes a proportional overflow valve I 31, a proportional overflow valve II 32, a proportional hydraulic control reversing valve 15, a fixed differential pressure reducing valve 14, and a shuttle valve 16.

[0097] Port 1 of the proportional hydraulic control reversing valve 15 is connected to C5, port 2 of the proportional hydraulic control reversing valve 15 is connected to C4, C4 is connected to port A of the motor II 26, port 3 of the proportional hydraulic control reversing valve 15 is connected to port 1 of the fixed differential pressure reducing valve 14, port 4 of the proportional hydraulic control reversing valve 15 is connected to C3, C3 is connected to port B of the motor II 26, port 5 of the proportional hydraulic control reversing valve 15 is connected to C2, port 6 of the proportional hydraulic control reversing valve 15 is connected to C6, and C5 and C6 are respectively connected to the standby module 19.

[0098] Port 1 of the proportional hydraulic control reversing valve 15 is connected to the inlet port of the proportional overflow valve I 31, port 6 of the proportional hydraulic control reversing valve 15 is connected to the inlet port of the proportional overflow valve II 32, and the outlet ports of the proportional overflow valve I 31 and the proportional overflow valve II 32 are connected to C8.

[0099] Port 2 of the fixed differential pressure reducing valve 14 is connected to C1, C1 is connected to the output end of the variable pump 10, port 3 of the fixed differential pressure reducing valve 14 is connected to the output port 3 of the shuttle valve 16, the output port 3 of the shuttle valve 16 is connected to C7, the selection port 1 of the shuttle valve 16 is connected to C3, and the selection port 2 of the shuttle valve 16 is connected to C4.

[0100] The difference between this embodiment and the second embodiment is that a proportional overflow valve I 31 is added to port 1 of the proportional hydraulic control reversing valve 15, and a proportional overflow valve II 32 is added to port 6 of the proportional hydraulic control reversing valve 15. By controlling the electro-hydraulic proportional overflow valve, the magnitude of the reversing pressure input to both ends of the proportional hydraulic control reversing valve 15 is controlled.

[0101] Embodiment Four

[0102] Refer to Figure 2 and Figure 4 In the engineering response valve block 25, there are oil ports, including C1, C2, C3, C4, C5, C6, C7, and C8.

[0103] The engineering response valve block 25 includes a direct-acting pressure reducing valve I 33, a direct-acting pressure reducing valve II 34, a proportional pressure reducing valve I 35, a proportional pressure reducing valve II 36, a fixed differential pressure reducing valve 14, a proportional hydraulic control reversing valve 15, and a shuttle valve 16.

[0104] Port 1 of the proportional hydraulic control reversing valve 15 is connected to C5, port 2 of the proportional hydraulic control reversing valve 15 is connected to C4, C4 is connected to port A of the motor II 26, port 3 of the proportional hydraulic control reversing valve 15 is connected to port 1 of the fixed differential pressure reducing valve 14, port 4 of the proportional hydraulic control reversing valve 15 is connected to C3, C3 is connected to port B of the motor II 26, port 5 of the proportional hydraulic control reversing valve 15 is connected to C2, port 6 of the proportional hydraulic control reversing valve 15 is connected to C6, and C5 and C6 are respectively connected to the spare module 19.

[0105] The direct-acting pressure reducing valve I 33 and the proportional pressure reducing valve I 35 are connected in series, the direct-acting pressure reducing valve I 33 is connected to C5, the proportional pressure reducing valve I 35 is connected to port 1 of the proportional hydraulic control reversing valve 15, the direct-acting pressure reducing valve I 33 and the proportional pressure reducing valve I 35 are respectively connected to C8, the direct-acting pressure reducing valve II 34 and the proportional pressure reducing valve II 36 are connected in series, the direct-acting pressure reducing valve II 34 is connected to C6, the proportional pressure reducing valve II 36 is connected to port 6 of the proportional hydraulic control reversing valve 15, and the direct-acting pressure reducing valve II 34 and the proportional pressure reducing valve II 36 are respectively connected to C8.

[0106] Port 2 of the fixed differential pressure reducing valve 14 is connected to C1, C1 is connected to the output end of the variable pump 10, port 3 of the fixed differential pressure reducing valve 14 is connected to the output port 3 of the shuttle valve 16, the output port 3 of the shuttle valve 16 is connected to C7, the selection port 1 of the shuttle valve 16 is connected to C3, and the selection port 2 of the shuttle valve 16 is connected to C4.

[0107] The difference between this embodiment and the third embodiment is that the proportional overflow valve I 31 and the proportional overflow valve II 32 in the third embodiment are replaced with a direct-acting pressure reducing valve I 33, a direct-acting pressure reducing valve II 34, a proportional pressure reducing valve I 35, and a proportional pressure reducing valve II 36. At port 1 of the proportional hydraulic control reversing valve 15, the direct-acting pressure reducing valve I 33 is used, and at port 6 of the proportional hydraulic control reversing valve 15, the direct-acting pressure reducing valve II 34 is used to first reduce the high-pressure control oil from the spare module 19 to the allowable inlet pressure of the proportional pressure reducing valve I 35 and the proportional pressure reducing valve II 36, and then the proportional pressure reducing valve I 35 and the proportional pressure reducing valve II 36 are used to control the reversing pressure at both ends of the proportional hydraulic control reversing valve 15.

[0108] Embodiment Five

[0109] Refer to Figure 2 and Figure 5 On the engineering response valve block 25, there are oil ports, and the oil ports include C1, C2, C3, C4, C5, C6, C7, and C8.

[0110] The engineering response valve block 25 includes a direct-acting pressure reducing valve 37, a proportional pressure reducing valve I 35, a proportional pressure reducing valve II 36, a constant differential pressure reducing valve 14, a proportional hydraulic control reversing valve 15, and a shuttle valve 16.

[0111] Port 1 of the proportional hydraulic control reversing valve 15 is connected to the oil outlet of the proportional pressure reducing valve II 36. Port 2 of the proportional hydraulic control reversing valve 15 is connected to C4, and C4 is connected to port A of the motor II 26. Port 3 of the proportional hydraulic control reversing valve 15 is connected to port 1 of the constant differential pressure reducing valve 14. Port 4 of the proportional hydraulic control reversing valve 15 is connected to C3, and C3 is connected to port B of the motor II 26. Port 5 of the proportional hydraulic control reversing valve 15 is connected to C2, and port 6 of the proportional hydraulic control reversing valve 15 is connected to C6. C5 and C6 are respectively connected to the spare module 19.

[0112] The oil inlet of the direct-acting pressure reducing valve 37 is connected to C6. The oil outlet of the direct-acting pressure reducing valve 37 is connected to the oil inlet of the proportional pressure reducing valve I 35. The oil outlet of the proportional pressure reducing valve I 35 is connected to port 6 of the proportional hydraulic control reversing valve 15. The oil inlet of the proportional pressure reducing valve II 36 is connected between the oil outlet of the direct-acting pressure reducing valve 37 and the oil inlet of the proportional pressure reducing valve I 35. The direct-acting pressure reducing valve 37, the proportional pressure reducing valve I 35, and the proportional pressure reducing valve II 36 are respectively connected to C8.

[0113] Port 2 of the constant differential pressure reducing valve 14 is connected to C1, and C1 is connected to the output end of the variable pump 10. Port 3 of the constant differential pressure reducing valve 14 is connected to the output port 3 of the shuttle valve 16. The output port 3 of the shuttle valve 16 is connected to C7. The selection port 1 of the shuttle valve 16 is connected to C3, and the selection port 2 of the shuttle valve 16 is connected to C4.

[0114] The difference between this embodiment and Embodiment 4 is that this embodiment consists of a direct-acting pressure reducing valve, two proportional pressure reducing valves, a proportional hydraulic control reversing valve, a constant differential pressure reducing valve, and a shuttle valve. After the high-pressure control oil is reduced in pressure by the direct-acting pressure reducing valve to the allowable pressure at the inlet of the proportional pressure reducing valve, the proportional hydraulic control reversing valve is controlled to reverse by the energization and de-energization of the proportional pressure reducing valve I and the proportional pressure reducing valve II, thereby controlling the reversal of the thruster II. The specific implementation steps are as follows:

[0115] The thruster II rotates forward:

[0116] When the control oil is reduced in pressure by the direct-acting pressure reducing valve 37 to the allowable pressure at the inlet of the proportional pressure reducing valve I 35, the proportional pressure reducing valve I 35 is energized, and the proportional pressure reducing valve II 36 is not energized. At this time, the pressure at port 6 of the proportional hydraulic control reversing valve 15 is the pressure after being reduced by the proportional pressure reducing valve I 35, the pressure at port 1 of the proportional hydraulic control reversing valve 15 is zero, the spool of the proportional hydraulic control reversing valve 15 moves to the left, and it works in the right position. The thruster control oil enters port A of the motor II 26 from the right position of the proportional hydraulic control reversing valve 15, driving the thruster II 30 to rotate forward.

[0117] The thruster II rotates in reverse:

[0118] When the control oil passes through the direct-acting pressure reducing valve 37 and is reduced to the allowable pressure at the inlet of the proportional pressure reducing valve II 36, the proportional pressure reducing valve II 36 is energized, and the proportional pressure reducing valve I 35 is not energized. At this time, the pressure at port 1 of the proportional hydraulically controlled directional valve 15 is the pressure reduced by the proportional pressure reducing valve II 36, the pressure at port 6 of the proportional hydraulically controlled directional valve 15 is zero, the spool of the proportional hydraulically controlled directional valve 15 moves to the right, and it works in the left position. The oil of the thruster also enters port B of the motor II 26 from the left position of the proportional hydraulically controlled directional valve 15, driving the thruster II 30 to reverse.

[0119] In the engineering response valve blocks of Embodiment Three, Embodiment Four, and Embodiment Five, a fixed-differential pressure reducing valve 14 and a shuttle valve 15 are both provided. Their connection positions and control logics are the same as those in Embodiment Two, and the purpose is to ensure that during the operation of the thruster, the working speed is not affected by the original seawater load and the speed is maintained at the originally set speed.

[0120] The above detailed description is a specific description of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or change without departing from the present invention shall be included in the patent scope of this case.

Claims

1. A hydraulic thruster control system for an underwater cable-laying robot, characterized in that: The system is a closed control system, which includes a closed pump, a main system, a thruster control valve group, a motor, a control oil source, and an oil tank; The two oil ports of the closed pump are respectively connected to the main system; The thruster control valve group is provided with oil ports, including C1, C2, C3, C4, C5, C6, C7 and C8, one oil port of the closed pump is connected to C1, and another oil port of the closed pump is connected to C2; The thruster control valve group includes a hydraulic valve V1, a hydraulic valve V2, a hydraulic valve V3, and a hydraulic valve V4, and the hydraulic valve V1 is connected in parallel to the hydraulic valve V2, and the hydraulic valve V3 is connected in parallel to the hydraulic valve V4; Port 1 of the hydraulic valve V1 is connected to the C6, the C6 is connected to port A of the motor, port 2 of the hydraulic valve V1 is connected to the C2, port 3 of the hydraulic valve V1 is connected to the C8, and the C8 is connected to the control oil source; Port 1 of the hydraulic valve V2 is connected to the C3, the C3 is connected to port B of the motor, and port 2 of the hydraulic valve V2 is connected to the C1; Port 1 of the hydraulic valve V3 is connected to C4, and C4 is connected to the pipeline between port A of the motor and C6, and port 2 of the hydraulic valve V3 is connected to C1; Port 1 of the hydraulic valve V4 is connected to C5, and C5 is connected to the pipeline between port B of the motor and C3, and port 2 of the hydraulic valve V4 is connected to C2; The four ports of the hydraulic valve V1, the four ports of the hydraulic valve V2, the four ports of the hydraulic valve V3 and the four ports of the hydraulic valve V4 are respectively connected to the C7, and the C7 is connected to the oil tank.

2. According to claim 1, a hydraulic thruster control system for an underwater cable-laying robot is characterized in that: The motor is connected to the propeller via a connecting shaft, the connecting shaft has a closed cavity, the closed cavity is connected to a compensator, and the compensator is respectively connected to two oil ports of the closed pump.

3. A hydraulic thruster control system for an underwater cable-laying robot, characterized in that: The system is an open control system, which includes a variable pump, an HCU control valve box, a thruster control valve block, and a motor I; The thruster control valve block is provided with oil ports, which include C1, C2, C3, C4, C5, C6 and C7; The thruster control valve block includes a differential pressure reducing valve, a proportional hydraulic control reversing valve, and a shuttle valve. Port 1 of the proportional hydraulic control reversing valve is connected to C5, port 2 of the proportional hydraulic control reversing valve is connected to C4, C4 is connected to port A of the motor I, port 3 of the proportional hydraulic control reversing valve is connected to outlet 7.1 of the differential pressure reducing valve, inlet 7.2 of the differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 4 of the proportional hydraulic control reversing valve is connected to C3, C3 is connected to port B of the motor I, port 5 of the proportional hydraulic control reversing valve is connected to C2, port 6 of the proportional hydraulic control reversing valve is connected to C6, spring chamber pressure oil port 7.3 of the differential pressure reducing valve is connected to output port 9.3 of the shuttle valve, selection oil port 9.1 of the shuttle valve is connected to C3, and selection oil port 9.2 of the shuttle valve is connected to C4; The HCU control valve box includes a thruster control valve, other control modules, and a spare module; The thruster control valve is provided with oil ports, which include D1, D2, D3 and D4, wherein D1 is connected to C5, D2 is connected to C6, and D3 is connected to the output end of the variable pump; The thruster control valve includes a pilot proportional reversing valve and a pilot proportional overflow valve, port 1 of the pilot proportional reversing valve is connected to D1, port 2 of the pilot proportional reversing valve is connected to D2, ports 3 and 4 of the pilot proportional reversing valve are respectively connected to the pilot proportional overflow valve, port 3 of the pilot proportional reversing valve is connected to D4, and port 4 of the pilot proportional reversing valve is connected to D3.

4. The hydraulic thruster control system of the underwater cable-laying robot according to claim 3, characterized in that: The output end of the variable pump is connected to a high-pressure filter, a one-way valve is connected between the high-pressure filter and the variable pump, and a safety valve is connected between the high-pressure filter and the one-way valve.

5. The hydraulic thruster control system of the underwater cable-laying robot according to claim 4, characterized in that: It also includes an engineering response valve block and a motor II. The engineering response valve block is connected to the standby module, the engineering response valve block is connected to the output end of the variable pump, and the A port and the B port of the motor II are respectively connected to the engineering response valve block.

6. The hydraulic thruster control system of the underwater cable-laying robot according to claim 5, characterized in that: The motor I is connected to the propeller I via the connecting shaft I, and the motor II is connected to the propeller II via the connecting shaft II. Both the connecting shaft I and the connecting shaft II have a closed cavity, and a compensator is connected between the closed cavity of the connecting shaft I and the closed cavity of the connecting shaft II.

7. The hydraulic thruster control system of the underwater cable-laying robot according to claim 6, characterized in that: The engineering response valve block is provided with oil ports, which include C1, C2, C3, C4, C5, C6, C7 and C8; The engineering response valve block includes a proportional relief valve I, a proportional relief valve II, a proportional hydraulic control reversing valve, a differential pressure reducing valve, and a shuttle valve; Port 1 of the proportional hydraulic control reversing valve is connected to C5, port 2 of the proportional hydraulic control reversing valve is connected to C4, C4 is connected to port A of the motor II, port 3 of the proportional hydraulic control reversing valve is connected to port 1 of the differential pressure reducing valve, port 4 of the proportional hydraulic control reversing valve is connected to C3, C3 is connected to port B of the motor II, port 5 of the proportional hydraulic control reversing valve is connected to C2, port 6 of the proportional hydraulic control reversing valve is connected to C6, and C5 and C6 are respectively connected to the standby module; Port 1 of the proportional hydraulically controlled reversing valve is connected to the oil inlet of the proportional relief valve I, port 6 of the proportional hydraulically controlled reversing valve is connected to the oil inlet of the proportional relief valve II, and the oil outlet of the proportional relief valve I and the oil outlet of the proportional relief valve II are connected to C8; Port 2 of the differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 3 of the differential pressure reducing valve is connected to output port 3 of the shuttle valve, output port 3 of the shuttle valve is connected to C7, selection port 1 of the shuttle valve is connected to C3, and selection port 2 of the shuttle valve is connected to C4.

8. The hydraulic thruster control system of the underwater cable-laying robot according to claim 6, characterized in that: The engineering response valve block is provided with oil ports, which include C1, C2, C3, C4, C5, C6, C7 and C8; The engineering response valve block includes a direct-acting pressure reducing valve I, a direct-acting pressure reducing valve II, a proportional pressure reducing valve I, a proportional pressure reducing valve II, a differential pressure reducing valve, a proportional hydraulically controlled reversing valve, and a shuttle valve; Port 1 of the proportional hydraulic control reversing valve is connected to C5, port 2 of the proportional hydraulic control reversing valve is connected to C4, C4 is connected to port A of the motor II, port 3 of the proportional hydraulic control reversing valve is connected to port 1 of the differential pressure reducing valve, port 4 of the proportional hydraulic control reversing valve is connected to C3, C3 is connected to port B of the motor II, port 5 of the proportional hydraulic control reversing valve is connected to C2, port 6 of the proportional hydraulic control reversing valve is connected to C6, and C5 and C6 are respectively connected to the standby module; The direct-acting pressure reducing valve I and the proportional pressure reducing valve I are connected in series, and the direct-acting pressure reducing valve I is connected to the C5, the proportional pressure reducing valve I is connected to the port 1 of the proportional hydraulic control reversing valve, the direct-acting pressure reducing valve I and the proportional pressure reducing valve I are connected to the C8 respectively, the direct-acting pressure reducing valve II and the proportional pressure reducing valve II are connected in series, and the direct-acting pressure reducing valve II is connected to the C6, the proportional pressure reducing valve II is connected to the port 6 of the proportional hydraulic control reversing valve, and the direct-acting pressure reducing valve II and the proportional pressure reducing valve II are connected to the C8 respectively; Port 2 of the differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 3 of the differential pressure reducing valve is connected to output port 3 of the shuttle valve, output port 3 of the shuttle valve is connected to C7, selection port 1 of the shuttle valve is connected to C3, and selection port 2 of the shuttle valve is connected to C4.

9. The hydraulic thruster control system of the underwater cable-laying robot according to claim 6, characterized in that: The engineering response valve block is provided with oil ports, which include C1, C2, C3, C4, C5, C6, C7 and C8; The engineering response valve block includes a direct-acting pressure reducing valve, a proportional pressure reducing valve I, a proportional pressure reducing valve II, a differential pressure reducing valve, a proportional hydraulically controlled reversing valve, and a shuttle valve; Port 1 of the proportional hydraulic control reversing valve is connected to the oil outlet of the proportional pressure reducing valve II, port 2 of the proportional hydraulic control reversing valve is connected to C4, C4 is connected to port A of the motor II, port 3 of the proportional hydraulic control reversing valve is connected to port 1 of the differential pressure reducing valve, port 4 of the proportional hydraulic control reversing valve is connected to C3, C3 is connected to port B of the motor II, port 5 of the proportional hydraulic control reversing valve is connected to C2, port 6 of the proportional hydraulic control reversing valve is connected to C6, and C5 and C6 are respectively connected to the standby module; The oil inlet of the direct-acting pressure reducing valve is connected to the C6, the oil outlet of the direct-acting pressure reducing valve is connected to the oil inlet of the proportional pressure reducing valve I, the oil outlet of the proportional pressure reducing valve I is connected to port 6 of the proportional hydraulic control reversing valve, the oil inlet of the proportional pressure reducing valve II is connected between the oil outlet of the direct-acting pressure reducing valve and the oil inlet of the proportional pressure reducing valve I, the direct-acting pressure reducing valve, the proportional pressure reducing valve I and the proportional pressure reducing valve II are respectively connected to the C8; Port 2 of the differential pressure reducing valve is connected to C1, C1 is connected to the output end of the variable pump, port 3 of the differential pressure reducing valve is connected to output port 3 of the shuttle valve, output port 3 of the shuttle valve is connected to C7, selection port 1 of the shuttle valve is connected to C3, and selection port 2 of the shuttle valve is connected to C4.

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