A passive hydraulic system and control method of double rack hydraulic cylinder

Abstract

The invention discloses a passive hydraulic system and control method of a double-rack hydraulic cylinder, which belongs to the technical field of ship motion control. The double-rack hydraulic cylinder comprises two cylinder bodies, rack pistons are installed in the cylinder bodies, the rack pistons in the two cylinder bodies move in opposite directions, a transmission shaft is installed between the two cylinder bodies, a gear is arranged outside the transmission shaft, the transmission shaft is connected to the racks of the two rack pistons through the gear, and the transmission shaft is connected to the precession shaft of the gyro stabilizer. The double-rack hydraulic cylinder of the invention brakes the gyro precession of the high-speed rotor, and the passive hydraulic system generates a pressure difference in the hydraulic oil in the two hydraulic cylinders through a two-position four-way proportional reversing valve, thereby generating a damping force on the precession of the gyro, thereby achieving the effect of suppressing the rolling of the ship.

Description

Technical Field

[0001] The invention belongs to the technical field of ship motion control, and in particular relates to a passive hydraulic system and a control method of a double-rack hydraulic cylinder. Background Art

[0002] Ship motion control has always been one of the core issues of ship maneuverability. Due to the interference of waves, the use of ships is greatly restricted. On the one hand, ships are in danger of capsizing in big waves, so ships have to stop at ports when the wind and waves are strong to avoid the risks brought by wind and waves. Especially in the deep sea, there are often strong winds and waves, which greatly limits the scope of use of ships. On the other hand, the vibration of ships caused by wind and waves will have a bad effect on the structure of the ship, such as fatigue damage, which seriously limits the service life of the ship. At the same time, the swaying motion of the ship caused by waves will cause great discomfort to the crew and passengers physiologically and psychologically. Especially when the ship is equipped with precision instruments and other vibration-sensitive devices, the ship's ability to suppress the interference of waves becomes more important. Therefore, when sailing on the sea, the roll of the ship will affect the seaworthiness, safety, normal operation of the equipment on board, and the comfort of the crew. In order to enable ships to operate stably for a long time in complex sea conditions, all kinds of ships have an urgent need for anti-rolling systems.

[0003] At present, the anti-roll system based on the control torque gyro (gyro anti-roll device) has been widely used. By utilizing the stable momentum moment output of its high-speed rotor and using a small torque input to produce precession, an amplified output torque can be obtained to suppress the ship's roll. However, the anti-roll system still has problems such as complex anti-roll control device, redundant hydraulic system, and poor applicability of the control strategy to waves.

[0004] Due to the development of computer technology and the maturity of various control theories, various active gyro anti-roll devices have been extensively studied and have become popular in the market. The gyro anti-roll device produced by ship power drives the gyro rotor to precess and generate anti-roll torque through motor drive and gear transmission. The technical feature of this system is the active control driven by the motor and high anti-roll efficiency. However, there is a potential risk that once the motor fails, the active control fails, and the high-speed rotating gyro is likely to aggravate the roll of the ship, and there is even a certain risk of capsizing.

[0005] NCTownsend et al. proposed a new gyro anti-roll control strategy. The gyro anti-roll device designed by them can generate a larger anti-roll torque than the existing gyro anti-roll device. Different from the previous gyro rotor precession control strategy, the paper proposes to make the gyro rotor precess continuously in one direction at a constant angular velocity, rather than oscillating near the vertical axis of the ship. In this way, the gyro rotor can make a full rotation along the gyro frame axis within one wave cycle. However, this control strategy has poor adaptability. For different marine environments, especially different wave interference excitations, the frequency and phase of the gyro rotor precession need to be adjusted in real time, and the operation is cumbersome.

[0006] Australian Vim Co., Ltd. has proposed a gyro stabilizer control system and method for stabilizing the motion of a sea vessel based on precession information. The control system adopts an automatic gain control (AGC) precession controller. The system operates using a gain coefficient, which is gradually minimized to allow the gyro flywheel to amplify the precession as much as possible, that is, the greater the precession, the greater the roll stabilization moment. This continuous gain change provides adaptability to changes in sea conditions and navigation conditions, and on this basis, a fault-tolerant ship anti-roll device control system has been developed. However, the control system uses two hydraulic cylinders to drive the high-speed rotor precession, which has the problem of hydraulic system redundancy and increases the complexity of the hydraulic device.

[0007] Wu Zhenya successfully developed a hydraulic damping gyro anti-roll device that suppresses the nonlinear roll of ships by using a rotating blade hydraulic damper as the precession mechanism. During the design process, the gyro output singularity was avoided by moving the gyro's center of gravity downward. The gyro anti-roll device designed by the institute achieved a roll reduction rate of 82.03% for a fishery administration ship. However, the rotating blade hydraulic damper has poor adaptability, and the damping precession cannot be adjusted according to sea conditions and navigation conditions.

[0008] In 2010, Chen Shaonan applied input-output linearization technology and backstepping control method to design a nonlinear gain controller to suppress ship roll, and verified through simulation that the device he designed has excellent roll reduction capability and heel disturbance balance recovery capability for real ships. However, the control strategy is complex, and there are no reports on its engineering application. Summary of the invention

[0009] The problem to be solved by the present invention is to provide a passive hydraulic system and a control method for a double-rack hydraulic cylinder.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is: a passive hydraulic system of a double-rack hydraulic cylinder, comprising a double-rack hydraulic cylinder and a two-position four-way proportional reversing valve, wherein the double-rack hydraulic cylinder comprises two cylinder bodies arranged in parallel, rack pistons are installed in the cylinder bodies, and the rack pistons in the two cylinder bodies move in opposite directions, a transmission shaft is installed between the two cylinder bodies, a gear is arranged on the outside of the transmission shaft, the transmission shaft is connected to the racks of the two rack pistons through the gear, and the transmission shaft is connected to the precession shaft of the gyro stabilizer; the precession torque generated by the gyro stabilizer is transmitted to the rack piston in the cylinder body through the gear, so as to push the hydraulic oil to flow and generate pressure; the hydraulic oil in the two cylinder bodies is squeezed into the other cylinder body through the two-position four-way proportional reversing valve respectively to form a hydraulic circuit; the hydraulic circuit is a pre-filled closed circuit, and the double-rack hydraulic cylinder acts as a plunger pump to provide power for the hydraulic circuit. A mathematical model for regulating the hydraulic circuit is established. By regulating the valve port size of the two-position four-way proportional reversing valve in the hydraulic circuit, the pressure difference can be regulated to provide braking for the rotation of the gear, thereby generating a damping torque on the precession of the gyro rotor of the gyro stabilizer to achieve a roll reduction effect.

[0011] It can be seen that the hydraulic circuit is the key to generating the damping torque for controlling the precession of the gyro. The hydraulic circuit can regulate the precession of the gyro rotor and add a damping torque in the precession direction of the gyro rotor.

[0012] Furthermore, a cylinder sleeve is arranged between the rack piston and the cylinder body, end walls are installed at both ends of the cylinder body, a gasket is arranged between the end wall and the cylinder body, an adjusting screw is installed on the end wall, and a fastening nut is installed on the adjusting screw; a retaining ring is arranged at the internal port position of the cylinder body, the outer side of the retaining ring is in contact with the end wall, and an O-ring is installed between the retaining ring and the inner wall of the cylinder body.

[0013] The adjusting screw and the fastening nut are used for testing and exhausting the pressure in the cylinder. The gasket and the O-ring are used for sealing the cylinder. The retaining ring is used to control the stroke of the rack piston. The rack piston and the gear cooperate to convert the hydraulic fluid transmission into the movement of the transmission shaft. The transmission shaft is connected to the precession shaft of the gyro stabilizer, and then the precession movement of the gyro is controlled by the double rack hydraulic cylinder, thereby controlling the roll of the ship.

[0014] Furthermore, an accumulator is provided on the hydraulic circuit, and a pressure sensor is installed on the accumulator.

[0015] Furthermore, a mathematical model for regulating the hydraulic circuit is established, comprising the following steps:

[0016] S1. The force of the double rack hydraulic cylinder is:

[0017]

[0018]

[0019] in, To resist the precession resistance of the double rack hydraulic cylinder. It is the power that promotes the precession of the double rack hydraulic cylinder circuit. is the inner diameter of the double rack hydraulic cylinder, The pressure of the double rack hydraulic cylinder against precession, is the pressure of the double rack hydraulic circuit, It is a fixed value determined by the energy storage device.

[0020] S2. According to the kinematics of the double rack hydraulic cylinder, the linear velocity of the rack piston is:

[0021]

[0022] in, is the linear velocity of the rack piston; is the hydraulic flow in the cylinder; is the radius of the gear; is the precession angular acceleration; it can be seen that during the working process, the motion states of the two hydraulic cylinders of the double rack hydraulic cylinder are the same, and the speed and hydraulic resistance they generate are also the same.

[0023] S3. When the hydraulic oil passes through the two-position four-way proportional reversing valve, a pressure difference will be generated. When the wall thickness of the valve port of the two-position four-way proportional reversing valve is Smaller than the diameter 1 / 2 of the valve port, and the valve port edge is a sharp edge without chamfering, the fluid at the valve port only contacts the valve port edge. This valve port can be considered as a thin-walled sharp-edge valve port. The flow calculation formula of the valve port is:

[0024]

[0025] in, is the pressure difference before and after the valve port; is the valve port area; is the density of hydraulic oil; is the flow coefficient; is the flow rate at the valve port. Then the pressure difference generated when the hydraulic oil passes through the two-position four-way proportional reversing valve is:

[0026]

[0027] S4. When the gear rotates, the hydraulic damping torque generated on both sides of the double rack hydraulic cylinder is:

[0028]

[0029]

[0030] in, is the hydraulic damping torque of the double rack hydraulic cylinder against the precession resistance, A hydraulic damping torque to promote precession for a double rack hydraulic cylinder circuit;

[0031] The total hydraulic damping torque is:

[0032]

[0033] in, is the total hydraulic damping torque;

[0034] Combining the above equations, we can get:

[0035]

[0036] Therefore, by reasonably controlling the size of the valve port of the two-position four-way proportional reversing valve, the damping torque applied to the precession direction of the gyroscope can be adjusted, thereby controlling the anti-roll torque of the gyroscope and achieving an anti-roll effect.

[0037] The present invention also provides a method for controlling a gyro stabilizer by a passive hydraulic system of a double-rack hydraulic cylinder, and controls the gyro stabilizer by a fuzzy adaptive PID control method.

[0038] Furthermore, the fuzzy adaptive PID control method comprises the following steps:

[0039] S100, set the roll angle target design value of the gyro stabilizer Set to 0; move the gyro precession angle away from the target design value of the maximum angle of the limit travel Set to 0 to set the absolute value of the maximum angle of the limit travel to 70°.

[0040] S200, input error value in fuzzy adaptive PID controller , Error change speed and the roll angle target design value of the gyro stabilizer The fuzzy adaptive PID controller continuously detects and , and then perform fuzzy reasoning based on fuzzy rules to calculate the response speed coefficient of PID , Steady-state error elimination coefficient and dynamic characteristics improvement factor Make online adjustments to meet the needs of different times and The demand generates the first gain B1;

[0041] S300, inputting the target design value of the gyro stabilizer precession angle away from the maximum angle of the limit stroke into the fuzzy adaptive PID controller , Response speed coefficient , Steady-state error elimination coefficient and dynamic characteristics improvement factor ,right , and Performing adaptive PID control to generate a second gain B2;

[0042] S400, combining the conventional PID control of step S300 and the fuzzy PID control of step S200 to generate and The two gains act together on the two-position four-way proportional reversing valve to control the reasonable precession of the gyro stabilizer.

[0043] The sensor on the gyro stabilizer will measure the real roll angle of the gyro stabilizer in real time and the real-time precession angle of the gyro stabilizer The feedback is given to the fuzzy adaptive PID controller respectively to achieve real-time adjustment.

[0044] The limit stroke is a stroke that can ensure that the gyro precession does not reach a singular point, because the singular point of the gyro precession has a great influence on the gyro anti-roll effect.

[0045] The specific effects of the present invention are as follows:

[0046] The double rack hydraulic cylinder of the present invention brakes the gyroscopic precession of the high-speed rotor, and adaptively controls the anti-rolling torque through a passive hydraulic system and a control strategy based on fuzzy PID, thereby achieving the effect of suppressing the ship's roll. In particular, the ship's roll motion caused by waves and environmental excitation forces is efficiently suppressed.

[0047] The present invention takes the gyro with a double rack hydraulic cylinder passive hydraulic damper as the precession mechanism as the research object. The passive hydraulic system generates a pressure difference between the hydraulic oil in the two hydraulic cylinders through a two-position four-way proportional reversing valve, thereby generating a damping force on the precession of the gyro. A joint dynamic equation is established for it, thereby establishing a mathematical model of the passive hydraulic system of the gyro anti-roll device. Based on the fuzzy PID control principle, an adaptive control strategy for the gyro anti-roll device is established, and the anti-roll effect of the passive ship anti-roll device based on the double rack hydraulic cylinder is verified through Simulink simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention in any sense. In the accompanying drawings:

[0049] Figure 1 It is a structural schematic diagram of the double rack hydraulic cylinder of the present invention.

[0050] Figure 2 It is a structural schematic diagram of the hydraulic circuit of the passive hydraulic system of the present invention.

[0051] Figure 3 It is the ship rolling response diagram of the present invention.

[0052] In the figure:

[0053] 1. Adjusting screw; 2. Fastening nut; 3. End wall; 4. Washer; 5. O-ring; 6. Retaining ring; 7. Cylinder liner; 8. Rack piston; 9. Gear; 10. Drive shaft; 11. Cylinder body; 13. Two-position four-way proportional reversing valve; 14. Accumulator; 15. Pressure sensor. DETAILED DESCRIPTION

[0054] like Figure 1 As shown, a double-rack hydraulic cylinder includes two parallel cylinder bodies 11, in which rack pistons 8 are installed. The rack pistons 8 in the two cylinder bodies 11 move in opposite directions. A transmission shaft 10 is installed between the two cylinder bodies 11, and a gear 9 is arranged on the outside of the transmission shaft 10. The transmission shaft 10 is connected to the racks of the two rack pistons 8 through the gear 9.

[0055] A cylinder sleeve 7 is arranged between the rack piston 8 and the cylinder body 11, end walls 3 are installed at both ends of the cylinder body 11, a gasket 4 is arranged between the end wall 3 and the cylinder body 11, an adjusting screw 1 is installed on the end wall 3, a fastening nut 2 is installed on the adjusting screw 1, a retaining ring 6 is arranged at the internal port position of the cylinder body 11, the outer side of the retaining ring 6 is in contact with the end wall 3, and an O-ring 5 is installed between the retaining ring 6 and the inner wall of the cylinder body 11.

[0056] The adjusting screw 1 and the fastening nut 2 are used for testing and exhausting the pressure in the cylinder 11. The gasket 4 and the O-ring 5 are used for sealing the cylinder 11. The retaining ring 6 is used to control the stroke of the rack piston 8. The rack piston 8 and the gear 9 cooperate to convert the hydraulic fluid transmission into the movement of the transmission shaft 10. The transmission shaft 10 is connected to the precession shaft of the gyro stabilizer, and then the precession movement of the gyro is controlled by the double rack hydraulic cylinder, thereby controlling the roll of the ship.

[0057] like Figure 2As shown, a passive hydraulic system of a double-rack hydraulic cylinder includes a double-rack hydraulic cylinder and a two-position four-way proportional reversing valve 13. The transmission shaft 10 of the double-rack hydraulic cylinder is fixedly connected to the precession shaft of the gyro stabilizer. The precession torque generated by the gyro stabilizer is transmitted to the rack piston 8 in the cylinder body 11 through the gear 9, pushing the hydraulic oil to flow and generating pressure; the hydraulic oil in the two cylinder bodies is squeezed into the other cylinder body through the fast-response two-position four-way proportional reversing valve 13 to form a hydraulic circuit.

[0058] An accumulator 14 is also provided on the hydraulic circuit, and a pressure sensor 15 is installed on the accumulator.

[0059] The hydraulic circuit is a pre-charged closed circuit, and there is no hydraulic pump, motor or reservoir in the hydraulic circuit. Since there is no hydraulic pump and oil tank in the hydraulic circuit, the double rack hydraulic cylinder acts as a plunger pump to provide power for the hydraulic circuit. A mathematical model for regulating the hydraulic circuit is established. By regulating the valve port size of the two-position four-way proportional reversing valve 13 in the hydraulic circuit, the pressure difference can be regulated to provide braking for the rotation of the gear 9, thereby generating a damping torque on the precession of the gyro rotor of the gyro stabilizer to achieve a gyro reduction effect.

[0060] It can be seen that the hydraulic circuit is the key to generating the damping torque to control the precession of the gyro. The hydraulic circuit can regulate the precession of the gyro rotor and add a damping torque in the precession direction of the gyro rotor.

[0061] Establishing a mathematical model for regulating the hydraulic circuit includes the following steps:

[0062] S1. The force of the double rack hydraulic cylinder is:

[0063]

[0064]

[0065] in, To resist the precession resistance of the double rack hydraulic cylinder. It is the power that promotes the precession of the double rack hydraulic cylinder circuit. is the inner diameter of the double rack hydraulic cylinder, The pressure of the double rack hydraulic cylinder against precession, is the pressure of the double rack hydraulic circuit, It is a fixed value determined by the energy storage device 14.

[0066] S2. According to the kinematics of the double rack hydraulic cylinder, the linear velocity of the rack piston 8 is:

[0067]

[0068] in, is the linear velocity of the rack piston 8; is the hydraulic flow in the cylinder 11; is the radius of gear 9; is the precession angular acceleration; it can be seen that during the working process, the motion states of the two hydraulic cylinders of the double rack hydraulic cylinder are the same, and the speed and hydraulic resistance they generate are also the same.

[0069] S3. When the hydraulic oil passes through the two-position four-way proportional reversing valve 13, a pressure difference will be generated. When the wall thickness of the valve port of the two-position four-way proportional reversing valve 13 is Smaller than the diameter If the valve port is 1 / 2 of the original valve port, and the valve port edge is a sharp edge without chamfering, the fluid at the valve port only contacts the valve port edge. This valve port can be considered as a thin-walled sharp-edge valve port. The flow calculation formula of the valve port is:

[0070]

[0071] in, is the pressure difference before and after the valve port ; is the valve port area ; is the density of hydraulic oil ; is the flow coefficient; is the flow rate at the valve port Then the pressure difference generated when the hydraulic oil passes through the two-position four-way proportional reversing valve 13 is:

[0072]

[0073] When S4 and gear 9 rotate, the hydraulic damping torque generated on both sides of the double rack hydraulic cylinder is:

[0074]

[0075]

[0076] in, is the hydraulic damping torque of the double rack hydraulic cylinder against the precession resistance, A hydraulic damping torque to promote precession for a double rack hydraulic cylinder circuit;

[0077] The total hydraulic damping torque is:

[0078]

[0079] in, is the total hydraulic damping torque;

[0080] Combining the above equations, we can get:

[0081]

[0082] Therefore, by reasonably controlling the size of the valve port of the two-position four-way proportional reversing valve 13, the damping torque applied to the precession direction of the gyro can be adjusted, thereby controlling the anti-rolling torque of the gyro to achieve an anti-rolling effect.

[0083] The present invention also provides a method for controlling a gyro stabilizer by a passive hydraulic system of a double-rack hydraulic cylinder, and controls the gyro stabilizer by a fuzzy adaptive PID control method.

[0084] The fuzzy adaptive PID control method includes the following steps:

[0085] S100, set the roll angle target design value of the gyro stabilizer Set to 0; move the gyro precession angle away from the target design value of the maximum angle of the limit travel Set to 0 to set the absolute value of the maximum angle of the limit travel to 70°.

[0086] S200, input error value in fuzzy adaptive PID controller , Error change speed and the roll angle target design value of the gyro stabilizer The fuzzy adaptive PID controller continuously detects and , and then perform fuzzy reasoning based on fuzzy rules to calculate the response speed coefficient of PID , Steady-state error elimination coefficient and dynamic characteristics improvement factor Make online adjustments to meet the needs of different times and The demand generates the first gain B1;

[0087] S300, inputting the target design value of the gyro stabilizer precession angle away from the maximum angle of the limit stroke into the fuzzy adaptive PID controller , Response speed coefficient , Steady-state error elimination coefficient and dynamic characteristics improvement factor ,right , and Performing adaptive PID control to generate a second gain B2;

[0088] S400, combining the conventional PID control of step S300 and the fuzzy PID control of step S200 to generate and The two gains act together on the two-position four-way proportional reversing valve 13 to control the reasonable precession of the gyro stabilizer.

[0089] The sensor on the gyro stabilizer will measure the actual roll angle of the gyro stabilizer in real time. and the real-time precession angle of the gyro stabilizer The feedback is given to the fuzzy adaptive PID controller respectively to achieve real-time adjustment.

[0090] The limit stroke is a stroke that can ensure that the gyro precession does not reach a singular point, because the singular point of the gyro precession has a great influence on the gyro anti-roll effect.

[0091] The present invention is based on the control strategy of double rack hydraulic cylinder, passive hydraulic system and fuzzy adaptive PID, and performs Matlab Simulink simulation of gyro stabilizer and ship rolling. Taking a certain ship as the research object, the bare hull structure is adopted, and interference factors such as bilge keel, rudder and other accessories are excluded.

[0092] In order to analyze the rolling motion of a ship under irregular waves, the sea conditions must be determined first. The significant wave height of the irregular sea conditions simulated by the present invention is 1m, the angular frequency is 0 to 4.5rad / s, the ship is at 0 speed, and the heading angle is 90°.

[0093] like Figure 3 As shown, the rolling of a ship without rolling reduction by the present invention and the rolling of a ship passively controlled by the present invention are compared over a period of time. It can be seen that the present invention can well suppress the nonlinear rolling of the ship.

[0094] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A passive hydraulic system of a double rack hydraulic cylinder, characterized in that: It comprises a double-rack hydraulic cylinder and a two-position four-way proportional reversing valve. The double-rack hydraulic cylinder comprises two cylinder bodies arranged in parallel. A rack piston is installed in the cylinder body. The rack pistons in the two cylinder bodies move in opposite directions. A transmission shaft is installed between the two cylinder bodies. A gear is arranged on the outer side of the transmission shaft. The transmission shaft is connected with the racks of the two rack pistons through the gear. The transmission shaft is connected with the precession shaft of the gyro stabilizer. The precession torque generated by the gyro stabilizer is transmitted to the rack piston in the cylinder body through the gear, so as to push the hydraulic oil to flow and generate pressure. The hydraulic oil in the two cylinder bodies is squeezed into the other cylinder body through the two-position four-way proportional reversing valve respectively to form a hydraulic circuit. The hydraulic circuit is a closed circuit. The double-rack hydraulic cylinder provides power for the hydraulic circuit. A mathematical model for regulating the hydraulic circuit is established. By regulating the valve port size of the two-position four-way proportional reversing valve in the hydraulic circuit, the pressure difference is regulated, the rotation of the gear is braked, and the precession of the gyro rotor of the gyro stabilizer is generated.

2. The passive hydraulic system of the double rack hydraulic cylinder according to claim 1, characterized in that: Establishing a mathematical model for regulating the hydraulic circuit comprises the following steps: S1. The force of the double rack hydraulic cylinder is: in, To resist the precession resistance of the double rack hydraulic cylinder. It is the power that promotes the precession of the double rack hydraulic cylinder circuit. is the inner diameter of the double rack hydraulic cylinder, The pressure of the double rack hydraulic cylinder against precession, is the pressure of the double rack hydraulic circuit; S2. According to the kinematics of the double rack hydraulic cylinder, the linear velocity of the rack piston is: in, is the linear velocity of the rack piston; is the hydraulic flow in the cylinder; is the radius of the gear; is the precession angular acceleration; During operation, the two hydraulic cylinders of the double rack hydraulic cylinder have the same motion state, and the speed and hydraulic resistance they generate are also the same; S3. When the hydraulic oil passes through the two-position four-way proportional reversing valve, a pressure difference is generated. The flow calculation formula of the valve port of the two-position four-way proportional reversing valve is: in, is the pressure difference before and after the valve port; is the valve port area; is the density of hydraulic oil; is the flow coefficient; is the flow rate at the valve port; the pressure difference generated when the hydraulic oil passes through the two-position four-way proportional reversing valve is: S4. When the gear rotates, the hydraulic damping torque generated on both sides of the double rack hydraulic cylinder is: in, is the hydraulic damping torque of the double rack hydraulic cylinder against the precession resistance, A hydraulic damping torque to promote precession for a double rack hydraulic cylinder circuit; The total hydraulic damping torque is: in, is the total hydraulic damping torque; Then we get: The damping torque applied to the precession direction of the gyroscope is adjusted by controlling the size of the valve port of the two-position four-way proportional reversing valve, thereby controlling the anti-rolling torque of the gyroscope.

3. The passive hydraulic system of the double rack hydraulic cylinder according to claim 1, characterized in that: A cylinder sleeve is arranged between the rack piston and the cylinder body, end walls are installed at both ends of the cylinder body, a gasket is arranged between the end wall and the cylinder body, an adjusting screw is installed on the end wall, and a fastening nut is installed on the adjusting screw; a retaining ring is arranged at the internal port position of the cylinder body, the outer side of the retaining ring is in contact with the end wall, and an O-ring is installed between the retaining ring and the inner wall of the cylinder body.

4. The passive hydraulic system of the double rack hydraulic cylinder according to claim 1, characterized in that: An accumulator is also provided on the hydraulic circuit, and a pressure sensor is installed on the accumulator.

5. A control method for a passive hydraulic system of a double rack hydraulic cylinder, based on the passive hydraulic system of a double rack hydraulic cylinder as claimed in any one of claims 1 to 4, characterized in that: The gyro stabilizer is controlled by fuzzy adaptive PID control method.

6. The control method of the passive hydraulic system of the double rack hydraulic cylinder according to claim 5, characterized in that: The fuzzy adaptive PID control method comprises the following steps: S100, setting the target design value of the roll angle of the gyro stabilizer to 0; setting the target design value of the precession angle of the gyro stabilizer away from the maximum angle of the limit stroke to 0, and setting the absolute value of the maximum angle of the limit stroke to 70°; S200, inputting the error amount, error change speed, and roll angle target design value of the gyro anti-roll into the fuzzy adaptive PID controller, the fuzzy adaptive PID controller continuously detects the error amount and error change speed during operation, and then performs fuzzy reasoning according to fuzzy rules to adjust the response speed coefficient, steady-state error elimination coefficient, and dynamic characteristic improvement coefficient of the PID online to meet the requirements of the error amount and error change speed at different times, thereby generating a first gain; S300, inputting a target design value of the precession angle of the gyro stabilizer away from the maximum angle of the limit stroke, a response speed coefficient, a steady-state error elimination coefficient, and a dynamic characteristic improvement coefficient into the fuzzy adaptive PID controller, and performing adaptive PID control on the response speed coefficient, the steady-state error elimination coefficient, and the dynamic characteristic improvement coefficient to generate a second gain; S400, combining the conventional PID control of step S300 and the fuzzy PID control of step S200 to generate a first gain and a second gain, which act together on a two-position four-way proportional reversing valve to control the reasonable precession of the gyro stabilizer.

7. The control method of the passive hydraulic system of the double rack hydraulic cylinder according to claim 6, characterized in that: The sensor on the gyro stabilizer feeds back the real roll angle of the gyro stabilizer and the real-time precession angle of the gyro stabilizer measured in real time to the fuzzy adaptive PID controller respectively, so as to realize real-time adjustment.

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