A trestle interactive compensation method

Abstract

The present invention provides a trestle interactive compensation method, wherein a detection wheel is installed at the head of a trestle telescopic channel, and then the telescopic distance of the piston in the single-piston rod cylinder of the compensation hydraulic system is calculated through a PID control module according to the numerical value of an encoder set on the detection wheel. When the trestle needs to be extended during active compensation, the servo proportional reversing valve is connected to the second oil circuit, and the liquid oil is directly connected to the A1 valve port of the single-piston rod cylinder after passing through the one-way valve 1 in the combination valve, thereby pushing the piston of the single-piston rod cylinder to extend, thereby driving the trestle to extend; when the trestle needs to be retracted during active compensation, the servo proportional reversing valve is connected to the third oil circuit, and the liquid oil is directly connected to the A2 valve port of the single-piston rod cylinder after passing through the one-way valve 4 in the combination valve, thereby pushing the piston of the single-piston rod cylinder to retract, thereby driving the trestle to shorten. The present invention can realize active compensation for the extension and retraction of the trestle, and can simultaneously control the hydraulic system that drives the trestle from being damaged. The method is highly practical and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of ship piers, and in particular to a pier interaction compensation method. Background Art

[0002] During offshore operations, such as oil exploration vessels used for deepwater oil exploration operations, or transporting personnel or cargo between ships equipped with large cranes, the ships will be affected by the marine environment such as wind, waves, and currents. Both the operating vessel and the target ship will float and swing in different directions, which will disturb the transfer pier and pose a safety hazard to personnel transfers at sea. Therefore, the relative position between the two ships needs to be considered to ensure the safety between the ships.

[0003] For example, the patent document with Chinese patent application number 202110450040.6 and publication date 2022.05.13 discloses an offshore transfer pier with wave compensation function and its working method, including a lifting and sinking mechanism, a pier system and an active wave compensation control system. The lifting and sinking mechanism includes a base, three base legs, an outer base, an inner base and a hydraulic cylinder; the pier system is a rotating double-arm telescopic structure, including a base, a boarding platform, a first hydraulic motor, a pier bridge body, a connecting shaft, a pitch device, an electromagnetic landing cone, and a first laser ranging sensor; the active wave compensation control system includes a control box, a laser radar, a main control computer, a second laser ranging sensor, a first encoder, a displacement sensor, a second encoder, an angle sensor, a third encoder, an inertial measurement unit, a tilt sensor, a three-degree-of-freedom compensation controller and a lifting and sinking compensation controller.

[0004] The above-mentioned literature compensates for the disturbance caused by the rocking motion of the two ships on the transfer trestle, thereby ensuring that the trestle bridge body maintains a safe angle with the horizontal plane during the personnel transfer process, thereby improving the safety and comfort of personnel transfer between the two ships at sea. However, it does not consider that during the active compensation process of the telescopic trestle, the trestle may be affected by passive external forces, causing the oil circuit of the hydraulic system driving the trestle to become blocked and generate high pressure, thereby damaging the hydraulic system. Summary of the Invention

[0005] The purpose of the present invention is to provide a trestle interactive compensation method, which can realize active compensation of the trestle expansion and contraction, and can control the hydraulic system driving the trestle from being damaged. The method is highly practical and reliable.

[0006] To achieve the above-mentioned purpose, a trestle interactive compensation method is provided, which realizes the telescopic compensation of the trestle through a compensating hydraulic system, comprising the following steps:

[0007] S1 installs a detection wheel at the head of the trestle telescopic channel, then controls the trestle to telescope and dock with the fixed platform, and makes the detection wheel abut against the fixed platform after docking. At the same time, the value of the encoder on the detection wheel is preset to 0 when docking is completed;

[0008] During the movement of the trestle, S2 obtains the signal of the encoder on the detection wheel through the PLC control module in the cabin control room, and then calculates the extension and retraction distance of the piston in the single piston rod cylinder through the PID control module;

[0009] S2.1 When the trestle moves closer to the fixed platform, the encoder value is greater than 0. The PID control module calculates the distance the piston in the single-piston rod cylinder needs to be shortened based on the changed value of the encoder. Then, the compensation hydraulic system controls the piston in the single-piston rod cylinder to shorten it.

[0010] S2.1.1 switches the servo proportional directional valve and presets the pressure of the second relief valve between the third and fourth oil circuits;

[0011] S2.1.2 Start the oil pump, so that the hydraulic oil is pumped out from the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit. Then it flows out of the servo proportional reversing valve into the third oil circuit, flows through the check valve 4, and flows into the single piston rod cylinder to push the piston to retract, thereby shortening the trestle.

[0012] S2.2 When the trestle moves in the opposite direction away from the fixed platform, the encoder value is less than 0. The PID control module calculates the required extension distance of the piston in the single-piston rod cylinder based on the changed value of the encoder, and then controls the piston in the single-piston rod cylinder to achieve extension through the compensation hydraulic system.

[0013] S2.2.1: Reverse the servo proportional directional valve and preset the pressure of the relief valve 1 between the second and fourth oil circuits.

[0014] S2.2.2 Start the oil pump, so that the hydraulic oil is pumped out from the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit, and then flows out of the servo proportional reversing valve into the second oil circuit, flows through the one-way valve and flows into the single-piston rod cylinder to push the piston to extend, thereby driving the trestle to extend.

[0015] The above method sets an encoder on the detection wheel, so that when the detection wheel moves, the value on the encoder changes accordingly, and then obtains the encoder signal through the PLC control module, so that the required extension and retraction distance of the piston in the single-piston rod cylinder corresponding to the movement of the detection wheel can be calculated through the PID control module, and then the piston in the single-piston rod cylinder is controlled by the compensation hydraulic system to achieve extension and retraction; and by setting the pressure value of the overflow valve, in the process of active compensation of the trestle after reversing by the servo proportional reversing valve, if the oil pressure in the oil circuit is higher than the pressure value set by the overflow valve, the overflow valve can be turned on, and the hydraulic oil can flow through the overflow valve through the fourth oil circuit and return to the oil tank, thereby actively reducing the oil pressure in the oil circuit, and better protecting the compensation hydraulic system and its components from damage.

[0016] Furthermore, the step S2.1.2 further includes the step of causing the hydraulic oil to flow through the control valve 2 into the fifth oil circuit and back to the oil tank if the hydraulic oil pressure in the oil circuit connected to the single-piston rod cylinder exceeds the pressure value set by the control valve 2 in the combination valve when the hydraulic oil is driven to shorten.

[0017] Step S2.2.2 also includes driving the trestle to extend. If the trestle is passively affected by external forces, causing the oil pressure in the oil circuit connected to the single-piston rod cylinder to be higher than the pressure value set by the control valve 1 in the combination valve, the control valve 1 is turned on, and the hydraulic oil flows through the control valve 1 into the fifth oil circuit and back to the oil tank.

[0018] The above setting, by setting a combination valve, when the trestle is passively subjected to external force so that the oil pressure in the oil circuit connected to the combination valve is higher than the pressure value set by the control valve, the hydraulic oil can flow through the control valve through the fifth oil circuit and return to the oil tank, thereby passively reducing the oil pressure in the oil circuit and better protecting the oil circuit and its components.

[0019] Furthermore, the encoder is fixedly mounted on one side of the detection wheel via a fastener.

[0020] The above settings can make the encoder and the detection wheel move synchronously and produce corresponding numerical changes.

[0021] Furthermore, the step S2.1 further includes:

[0022] S2.1.3 After the trestle is shortened, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0;

[0023] Step S2.2 also includes:

[0024] S2.2.3 After the trestle is extended, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0.

[0025] The above arrangement ensures that the relative position between the trestle and the fixed platform remains unchanged.

[0026] Furthermore, the step S2 further includes a PID control module obtaining a value of an encoder according to the PLC control module, and then calculating the corresponding extension and retraction distance of the piston in the single-piston rod cylinder by a PID algorithm.

[0027] The above arrangement facilitates pushing the piston in the single-piston rod cylinder to achieve corresponding extension and retraction through the compensating hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the compensating hydraulic system in the present invention.

[0029] Figure 2 for Figure 1 Enlarged view of point D in the middle.

[0030] Figure 3 It is the workflow diagram of the present invention.

[0031] Figure 4 This is a workflow diagram of step S2.1 in the present invention.

[0032] Figure 5 This is a workflow diagram of step S2.2 in the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figures 1 to 2 As shown, a trestle interactive compensation method is used to achieve telescopic compensation of the trestle through a compensating hydraulic system. The compensating hydraulic system includes a first oil circuit 1, a shuttle valve 6, a servo proportional reversing valve 7, a second oil circuit 2, a third oil circuit 3, a fourth oil circuit 4, a fifth oil circuit 5, a combination valve, a single-piston rod cylinder 8, an oil pump 9, an oil tank 10 and two or more relief valves. One end of the first oil circuit 1 is connected to the oil tank 10, and the other end of the first oil circuit 1 is connected to the P1 valve port of the servo proportional reversing valve 7. In this embodiment, a pressure compensation valve is provided in the first oil circuit 1. The oil tank 10 is connected to one end of the pressure compensating valve 11 through the oil pump 9, and the other end of the pressure compensating valve 11 is connected to the P1 valve port of the servo proportional reversing valve 7. The hydraulic oil in the oil tank 10 can be supplied to the first oil circuit 1 through the oil pump 9, and the pressure of the hydraulic oil is increased through the pressure compensating valve 11 to flow to the servo proportional reversing valve 7. The shuttle valve 6 is connected to the pressure compensating valve 11, and the two ends of the shuttle valve 11 are respectively connected to the second oil circuit 2 and the third oil circuit 2. The shuttle valve 6 is used to prevent the second oil circuit 2 and the third oil circuit 3 from being connected at the same time.

[0035] The P3 valve port of the servo proportional reversing valve 7 is connected to one end of the combination valve through the second oil circuit 2, and the P4 valve port of the servo proportional reversing valve 7 is connected to one end of the combination valve through the third oil circuit 3. The other end of the combination valve is connected to the single-piston rod cylinder 8. In this embodiment, the combination valve includes a control valve a1, a control valve a2, and two or more one-way valves. The one-way valves include a one-way valve s1, a one-way valve s2, a one-way valve s3, and a one-way valve s4. Both ends of the single-piston rod cylinder 8 are connected to the second oil circuit 2 and the third oil circuit 3 respectively through the one-way valves. The single-piston rod cylinder 8 is provided with an A1 valve port and an A2 valve port. Figure 2 As shown, one end of the second oil circuit 2 is connected to the P3 valve port of the servo proportional reversing valve 7, one end of the one-way valve s1 is respectively connected to the other end of the second oil circuit 2 and the other end of the control valve a2, and the A1 valve port of the single-piston rod cylinder 8 is respectively connected to one end of the one-way valve s2, one end of the control valve a1, and the other end of the one-way valve s1. In this way, when the servo proportional reversing valve 7 is connected to the second oil circuit 2 alone to control the piston of the single-piston rod cylinder 8 to extend, it is passively subjected to external forces, causing the oil pressure of the liquid oil to be higher than the pressure set by the control valve a1. When the pressure is set to 70 bar in this embodiment, the pressure value set by the control valve a1 is 70 bar, which can allow some of the liquid oil to flow through the control valve a1, through the fifth oil passage 5, and then back to the oil tank 10, thereby relieving some of the pressure; one end of the third oil passage 3 is connected to the valve port P4 of the servo proportional reversing valve 7, one end of the check valve 4 s4 is connected to the other end of the third oil passage 3 and the other end of the control valve a1, respectively; the valve port A2 of the single-piston rod cylinder 8 is connected to one end of the check valve 3 s3, one end of the control valve 2 a2, and the other end of the check valve 4 s4, respectively. In this way, when the servo proportional reversing valve 7 is connected to the third oil circuit 3 alone to control the piston of the single-piston rod cylinder 8 to retract and is passively subjected to external forces so that the oil pressure is higher than the pressure value set by the control valve a2, in this embodiment, the pressure value set by the control valve a2 is 70 bar, which can make part of the oil flow through the control valve a2 through the fifth oil circuit 5 and then flow back to the oil tank 10, thereby relieving part of the pressure; the oil tank 10 is connected to the control valve a1 and the control valve a2 respectively through the fifth oil circuit 5. Specifically, one end of the fifth oil circuit 5 is connected to the oil tank 10. They are respectively connected to the other end of the one-way valve 2 s2, the other end of the one-way valve 3 s3, the control valve 1 a1 and the control valve 2 a2, and the other end of the fifth oil circuit 5 is connected to the oil tank. In this way, by arranging the one-way valve 2 s2 and the one-way valve 3 s3 to be respectively connected to the two ends of the single-piston-rod cylinder 8, it is possible to prevent the liquid oil in the single-piston-rod cylinder 8 from directly connecting to the fifth oil circuit 5 and flowing back to the oil tank 10, so that the oil pressure of the single-piston-rod cylinder 8 drops to zero instantly. Instead, local pressure relief is achieved by the liquid oil flowing through the control valve 1 a1 and the control valve 2 a2 and flowing back to the oil tank 10 through the fifth oil circuit 5.

[0036] like Figure 1As shown, overflow valves are connected between the second oil circuit 2 and the fourth oil circuit 4 and between the third oil circuit 3 and the fourth oil circuit 4. The overflow valves include overflow valve 1 z1 and overflow valve 2 z2. One end of overflow valve 1 z1 is connected to the second oil circuit 2, one end of overflow valve 2 z2 is connected to the third oil circuit 3, the other end of overflow valve 1 z1 and the other end of overflow valve 2 z2 are connected to the fourth oil circuit 4, one end of the fourth oil circuit 4 is connected to the P2 valve port of the servo proportional reversing valve 7, and the other end of the fourth oil circuit 4 is connected to the oil tank. In this way, during the active compensation process of the trestle through the servo proportional reversing valve 7, when the oil pressure in the second oil circuit 2 is greater than the pressure value set by the overflow valve 1 z1, in this embodiment, the overflow valve The pressure value set by overflow valve z1 is 30 bar. When overflow valve z1 is turned on, the liquid oil in the second oil circuit 2 can flow into the fourth oil circuit 4 through overflow valve z1, and then flow back to the oil tank 10, actively reducing the oil pressure in the second oil circuit 2; when the oil pressure in the third oil circuit 3 is greater than the pressure value set by overflow valve z2, in this embodiment, the pressure value set by overflow valve z2 is 45 bar. When overflow valve z2 is turned on, the liquid oil in the third oil circuit 3 can flow into the fourth oil circuit 4 through overflow valve z2, and then flow back to the oil tank 10, actively reducing the oil pressure in the third oil circuit 3, thereby protecting the single-piston rod cylinder 8 and preventing the single-piston rod cylinder 8 from being damaged due to excessive oil pressure.

[0037] In this embodiment, when the servo proportional reversing valve 7 is disconnected from both the second oil circuit 2 and the third oil circuit 3 , the trestle is in a stationary state.

[0038] In this embodiment, the encoder is fixedly mounted on one side of the detection wheel by fasteners, which are bolts and nuts, so that the encoder and the detection wheel can move synchronously and generate corresponding numerical changes.

[0039] like Figure 3-5 As shown, a trestle interactive compensation method also includes the following specific steps:

[0040] S1 installs a detection wheel at the head of the trestle telescopic channel, then controls the trestle telescopic docking with the fixed platform, and makes the detection wheel abut against the fixed platform after docking. At the same time, the value of the encoder set on the detection wheel is preset to 0 when the docking is completed. In this embodiment, the fixed platform is set on the target ship.

[0041] During the movement of the trestle, S2 obtains the signal of the encoder on the detection wheel through the PLC control module in the cabin control room, and then makes the PID control module calculate the corresponding extension and contraction distance of the piston in the single piston rod cylinder through the PID algorithm according to the value of the encoder obtained by the PLC control module. In this embodiment, the PLC control module and the encoder on the detection wheel are connected by a cable. The PID algorithm is a prior art and will not be described in detail here.

[0042] S2.1 When the trestle moves closer to the fixed platform, the encoder value is greater than 0. The PID control module calculates the distance the piston in the single-piston rod cylinder needs to be shortened based on the changed value of the encoder. Then, the compensation hydraulic system controls the piston in the single-piston rod cylinder to shorten it.

[0043] S2.1.1 switches the servo proportional directional valve and presets the pressure of the relief valve 2 between the third and fourth oil circuits to 45 bar.

[0044] S2.1.2 Start the oil pump, so that the hydraulic oil is pumped out of the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit. Then, it flows out of the servo proportional reversing valve into the third oil circuit, flows through the check valve four, and flows into the single-piston rod cylinder to push the piston to retract, thereby driving the trestle to shorten. In addition, during the process of driving the trestle to shorten, if the trestle is passively affected by external forces and the oil pressure in the oil circuit connected to the single-piston rod cylinder is higher than the pressure value set by the control valve two in the combination valve, the pressure value of the control valve two is 70 bar, causing the control valve two to conduct, thereby allowing the hydraulic oil to flow through the control valve two into the fifth oil circuit and back to the oil tank;

[0045] S2.1.3 After the trestle is shortened, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0;

[0046] S2.2 When the trestle moves in the opposite direction away from the fixed platform, the encoder value is less than 0. The PID control module calculates the required extension distance of the piston in the single-piston rod cylinder based on the changed value of the encoder, and then controls the piston in the single-piston rod cylinder to achieve extension through the compensation hydraulic system.

[0047] S2.2.1: Reverse the servo proportional directional valve and preset the pressure of the relief valve 1 between the second and fourth oil circuits to 30 bar.

[0048] S2.2.2 Start the oil pump, so that the hydraulic oil is pumped out of the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit. Then, it flows out of the servo proportional reversing valve into the second oil circuit, flows through the one-way valve 1, and flows into the single-piston rod cylinder to push the piston to extend, thereby driving the trestle to extend. In addition, during the process of driving the trestle to extend, if the trestle is passively affected by external forces and the oil pressure in the oil circuit connected to the single-piston rod cylinder is higher than the pressure value set by the control valve 1 in the combination valve, the pressure value of the control valve 1 is 70 bar, causing the control valve 1 to be conductive, thereby allowing the hydraulic oil to flow through the control valve 1 into the fifth oil circuit and back to the oil tank;

[0049] S2.2.3 After the trestle is extended, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0.

[0050] The working principle of the present invention is as follows: the detection wheel is installed at the head of the telescopic channel of the trestle, and then the distance of the piston extension and contraction in the single piston rod cylinder of the compensation hydraulic system is calculated through the PID control module according to the value of the encoder set on the detection wheel. When the trestle needs to be extended during active compensation, the servo proportional reversing valve 7 is connected to the second oil circuit 2, and the liquid oil passes through the one-way valve s2 in the combination valve and is directly connected to the A1 valve port of the single piston rod cylinder 8, pushing the piston of the single piston rod cylinder 8 to extend, thereby driving the trestle to extend. In addition, through the second oil circuit 2 can realize active pressure relief, and passive pressure relief is realized through the control valve a1 in the combination valve; when the trestle needs to be retracted during active compensation, the servo proportional reversing valve 7 is connected to the third oil circuit 3, and the liquid oil passes through the one-way valve 4 s4 in the combination valve and is directly connected to the A2 valve port of the single-piston rod cylinder 8, pushing the piston of the single-piston rod cylinder 8 to retract, thereby driving the trestle to shorten. In addition, active pressure relief can be realized through the overflow valve z2 in the third oil circuit 3, and passive pressure relief can be realized through the control valve a2 in the combination valve.

Claims

1. A trestle interactive compensation method, which realizes the expansion and contraction compensation of the trestle through a compensating hydraulic system, characterized by: The following steps are involved: S1 installs a detection wheel at the head of the trestle telescopic channel, then controls the trestle to telescope and dock with the fixed platform, and makes the detection wheel abut against the fixed platform after docking. At the same time, the value of the encoder on the detection wheel is preset to 0 when docking is completed; During the movement of the trestle, S2 obtains the signal of the encoder on the detection wheel through the PLC control module in the cabin control room, and then calculates the extension and retraction distance of the piston in the single piston rod cylinder through the PID control module; S2.1 When the trestle moves closer to the fixed platform, the encoder value is greater than 0. The PID control module calculates the distance the piston in the single-piston rod cylinder needs to be shortened based on the changed value of the encoder. Then, the compensation hydraulic system controls the piston in the single-piston rod cylinder to shorten it. S2.1.1 switches the servo proportional directional valve and presets the pressure of the second relief valve between the third and fourth oil circuits; S2.1.2 Start the oil pump, so that the hydraulic oil is pumped out from the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit. Then it flows out of the servo proportional reversing valve into the third oil circuit, flows through the check valve 4, and flows into the single piston rod cylinder to push the piston to retract, thereby shortening the trestle. S2.2 When the trestle moves in the opposite direction away from the fixed platform, the encoder value is less than 0. The PID control module calculates the required extension distance of the piston in the single-piston rod cylinder based on the changed value of the encoder, and then controls the piston in the single-piston rod cylinder to achieve extension through the compensation hydraulic system. S2.2.1: Reverse the servo proportional directional valve and preset the pressure of the relief valve 1 between the second and fourth oil circuits. S2.2.2 Start the oil pump, so that the hydraulic oil is pumped out from the oil tank through the oil pump into the first oil circuit, and then flows into the servo proportional reversing valve after passing through the pressure compensation valve in the first oil circuit, and then flows out of the servo proportional reversing valve into the second oil circuit, flows through the one-way valve and flows into the single-piston rod cylinder to push the piston to extend, thereby driving the trestle to extend.

2. A trestle interactive compensation method according to claim 1, characterized in that: The step S2.1.2 further includes: during the shortening of the trestle, if the trestle is passively subjected to an external force causing the oil pressure in the oil circuit connected to the single-piston rod cylinder to be higher than the pressure value set by the second control valve in the combination valve, the second control valve is turned on, thereby allowing the hydraulic oil to flow through the second control valve into the fifth oil circuit and back to the oil tank; Step S2.2.2 also includes driving the trestle to extend. If the trestle is passively affected by external forces, causing the oil pressure in the oil circuit connected to the single-piston rod cylinder to be higher than the pressure value set by the control valve 1 in the combination valve, the control valve 1 is turned on, and the hydraulic oil flows through the control valve 1 into the fifth oil circuit and back to the oil tank.

3. The interactive compensation method for a trestle according to claim 1, characterized in that: The encoder is fixedly mounted on one side of the detection wheel through a fastener.

4. The trestle interactive compensation method according to claim 1, characterized in that: The step S2.1 further includes: S2.1.3 After the trestle is shortened, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0; Step S2.2 also includes: S2.2.3 After the trestle is extended, the detection wheel rotates in the opposite direction to reset, and the value on the encoder is reset to 0.

5. The trestle interactive compensation method according to claim 1, characterized in that: The step S2 further includes the PID control module obtaining the value of the encoder according to the PLC control module, and then calculating the corresponding extension and retraction distance of the piston in the single-piston rod cylinder through the PID algorithm.

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