Hydraulic station based on servo drive and control method

Abstract

The invention relates to the technical field of hydraulic power, in particular to a hydraulic station based on servo drive and a control method.The hydraulic station comprises a machine box, a servo drive module, an oil pump, a first oil way, a second oil way, a hydraulic cylinder and a hydraulic loop, an oil tank is arranged in the machine box, and the first oil way is provided with a first reversing valve, a first pressure sensor, an overflow valve and a cartridge valve; the first reversing valve is used for being connected with an oil pump, the first pressure sensor is used for detecting pressure of a first oil way, and the overflow valve and the cartridge valve are connected with the first reversing valve. An output oil way of the first reversing valve is connected with the second oil way, the hydraulic loop is connected with a backflow oil way of the second oil way, and the hydraulic loop is connected with the oil tank to form a loop; the second oil way is provided with a second reversing valve, and an output oil way of the second reversing valve is provided with an electromagnetic ball valve connected with the hydraulic cylinder. The oil tank, the servo driving module, the oil pump and other key components are integrated in the case, and the reliability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic power technology, and in particular to a servo-driven hydraulic station and a control method thereof. Background Art

[0002] Hydraulic drive systems have long played a key role in industrial production and numerous engineering fields. Traditional hydraulic drive systems have certain capabilities in achieving power transmission and mechanical motion control. However, with the increasing requirements of modern industry for equipment performance, precision, and automation, existing hydraulic drives without servo technology have exposed many limitations. Hydraulic drive systems lacking servo control have relatively low control accuracy. Due to the inability to accurately sense and adjust system parameters in real time, it is difficult to achieve ideal position, speed, and force control effects when performing complex or high-precision motion tasks, resulting in unstable product quality and limited production efficiency.

[0003] The response speed of existing hydraulic drives often fails to meet the demands of rapidly changing operating conditions. In some work scenarios requiring rapid starts and stops and frequent direction changes, the lag of non-servo hydraulic drives becomes prominent, significantly compromising the dynamic performance of the entire system. Therefore, a new design for the existing hydraulic station is necessary. Summary of the Invention

[0004] To solve the above problems, the chassis of the present invention integrates key components such as the oil tank, servo drive module, and oil pump, and the oil circuits are arranged in an orderly manner, which not only saves installation space, but also reduces the risk of leakage caused by complex pipeline connections, improves the reliability and maintenance convenience of the system, and reduces the operating cost of the servo-driven hydraulic station and control method.

[0005] The technical solution adopted by the present invention is: a servo-driven hydraulic station, including a chassis, a servo drive module, an oil pump, a first oil circuit, a second oil circuit, a hydraulic cylinder and a hydraulic circuit, an oil tank is provided in the chassis, the servo drive module is arranged on the chassis and is connected to the oil pump drive to drive the oil pump to work, the oil pump is used to connect the oil tank and the first oil circuit for supplying oil to the first oil circuit; the first oil circuit is provided with a first reversing valve, a first pressure sensor, a relief valve and a cartridge valve, the first reversing valve is used to connect the oil pump, the first pressure sensor is used to detect the pressure of the first oil circuit, the relief valve and the cartridge valve are both connected to the first reversing valve; the output oil circuit of the first reversing valve is connected to the second oil circuit, the hydraulic circuit is connected to the return oil circuit of the second oil circuit, and the hydraulic circuit is connected to the oil tank to form a circuit; the second oil circuit is provided with a second reversing valve, and the output oil circuit of the second reversing valve is provided with an electromagnetic ball valve connected to the hydraulic cylinder.

[0006] A further improvement to the above scheme is that the servo drive module is provided with a servo controller, the first reversing valve is provided with a control module V1, two second reversing valves are provided, the two second reversing valves respectively include a control module V2 and a control module V3, the electromagnetic ball valve is provided with a control module V4, and the servo controller is electrically controlled and connected to the control module V1, control module V2, control module V3 and control module V4.

[0007] A further improvement to the above scheme is that the servo drive module is a servo motor, the servo motor is connected to the oil pump through a coupling, the oil pump is provided with a first output port and a second output port, the first output port is connected to the second oil circuit through a first oil circuit, the second output port is connected to the first reversing valve through a cartridge valve, the first output port is provided with a branch oil circuit, the branch oil circuit is provided with a one-way valve, and the one-way valve is connected to the first reversing valve.

[0008] A further improvement to the above scheme is that the oil tank is arranged in the chassis, an oil suction net is provided in the oil tank, the oil suction net is provided on the oil pump, a temperature sensor and a liquid level meter are provided in the oil tank, and the chassis is provided with a refueling port, which is used to refuel the tank.

[0009] A further improvement to the above solution is that a quick connection module is provided between the first oil circuit and the second oil circuit, the quick connection module includes a quick connector and a transition plate, the transition plate is used to connect the second oil circuit, and the quick connector is used to connect the first oil circuit and the second oil circuit.

[0010] A further improvement to the above solution is that the second oil circuit is provided with a damper and a second pressure sensor, the second pressure sensor is used to detect the oil pressure of the second oil circuit, and the damper is used to generate damping in the second oil circuit.

[0011] A further improvement to the above solution is that the hydraulic circuit includes an oil return filter, the oil return filter is connected to the oil tank, and an air cooling device is provided on one side of the oil return filter, and the air cooling device is used to cool the liquid filtered by the oil return filter.

[0012] A further improvement to the above scheme is that the servo controller controls the servo drive module to start, and the control module V1, control module V3 and control module V4 are turned on to drive the hydraulic cylinder to press down quickly; the control module V3 and control module V4 are turned on to drive the hydraulic cylinder to press down slowly; the control module V1, control module V2 and control module V4 are turned on to drive the hydraulic cylinder to rise quickly.

[0013] A servo-driven hydraulic control method includes a servo-driven hydraulic station, and the hydraulic control method includes the following methods: Step S1, Mode Prediction Phase: After receiving the instructions from the host computer through the CAN bus, the servo controller executes: Parse the speed parameter v and the load parameter F in the instructions. When v ≥ 50 and F ≥ 100, activate the fast downward pressure mode. When 10 < v < 50 and 50 < F < 100, activate the slow downward pressure mode. When v ≥ 80 and F < 50, activate the fast upward mode; Step S2, Dynamic Parameter Matching Phase: Automatically configure parameters according to the selected mode: In M1 mode: Set the PWM frequency f1 of control module V1 to 10kHz ± 5%, and the duty cycle D1 to 85% ± 3%; The holding current I3 of control module V3 is 1.2A ± 0.1A; The turn-on response time t4 of control module V4 is t4 ≤ 5ms; In M2 mode: Set the PWM frequency f1 of V1 to 5kHz ± 5%, and the duty cycle D1 to 60% ± 3%; The holding current I3 of V3 is 0.8A ± 0.1A; The turn-on response time t4 of V4 is t4 = 15 - 20ms; In M3 mode: Set the PWM frequency f1 of V1 to 15kHz ± 5%, and the duty cycle D1 to 95% ± 3%; The pulse width W2 of V2 is W2 = 200μs ± 10%; The spool opening θ4 of V4 is θ4 = 90% ± 2%; Step S3, Real-time Compensation Phase: Execute closed-loop control through the sensor network: Collect the main oil circuit pressure P through the first pressure sensor, and collect the real-time position L through the oil cylinder displacement sensor; When |dP / dt| ≥ 20bar / s, trigger the pressure fluctuation suppression algorithm: Adjust the duty cycle of V1, ΔD1 = Kp*(dP / dt)+Ki*∫(dP / dt)dt, where Kp = 0.5% / bar / s and Ki = 0.2% / bar; Synchronously adjust the spool opening of V4, θ4 = θ4_initial - 0.8*(dP / dt) When the displacement acceleration a = d²L / dt² ≥ 500mm / s², activate the anti-shock strategy: Reduce the holding current of V3 by 30% within 10ms, and send a reverse compensation pulse to V2, with the pulse width W2_comp = 50μs ± 5%.

[0014] A further improvement to the above solution is that it also includes the following cross-domain control strategies: Thermal-hydraulic coupling control: Collect the oil temperature T in real time through the temperature sensor; Establish a heat balance equation: Q_gen = αPv + βF² / R Q_cool = γ(T - T_amb)*v_fan where α = 0.015W / (bar·mm / s), β = 0.0008W / (kN²·Ω), γ = 0.12W / (℃·m / s) c) When T≥65℃, execute: Increase the speed of the air cooling device to N_fan=2000+50*(T-65)rpm; Add temperature compensation current ΔI3=0.05*(T-60)A to the V3 control loop; Limit the maximum speed of the servo motor ω_max=ω_nom*[1-0.015*(T-60)] Fluid-solid coupling vibration suppression: The vibration spectrum data of the oil block is collected through the acceleration sensor; when the vibration amplitude A ≥ 0.5g in the 200-500Hz frequency band is detected: Inject anti-phase harmonics into the PWM signal of V1, harmonic order n=3,5,7 Adjust the valve core movement trajectory of V4 as follows: θ(t)=θ0+Δθsin(2πft+φ) Where f = vibration frequency ± 10 Hz, Δθ = 0.5°~1.5°, φ = 180°±5°; At the same time, the active control mode of the hydraulic damper is activated, applying the damping force: F_damp=Kdv_pipe+Cd*dv_pipe / dt Where Kd=50N·s / m, Cd=20N·s² / m².

[0015] Further improvements to the above solution include the following fault response mechanisms: Sensor fault diagnosis: Perform double calibration on the pressure sensor: The difference between the main sensor P1 and the redundant sensor P2 |ΔP|=|P1-P2|; When |ΔP|≥5bar for 100ms, the sensor health assessment is activated: Send a test pulse signal to V4 and observe the response delay of P1 / P2. If the delay difference is ≥ 2ms, determine that the sensor is faulty and switch to the backup channel. Self-calibration of the oil temperature sensor: Perform zero point calibration every 24 hours: T_cal=T_raw-0.5*(T_env-25℃) When dT / dt≥10℃ / s, the thermocouple cold junction compensation algorithm is activated; Actuator fault recovery: When a V1 driver abnormality is detected: Transfer control to the backup PWM generator within 50ms; At the same time, adjust the duty cycle compensation of V2 to ΔD2 = 1.2*(1-D1 / D1_nom); When V3 is stuck: apply a sweep frequency signal with increasing amplitude to the V3 coil. If the valve core does not reset, establish a reverse oil pressure ΔP=20-30bar through V2 for mechanical unlocking.

[0016] The beneficial effects of the present invention are: Compared to existing hydraulic stations, the present invention achieves precise control of key hydraulic station components through the electrical connection between the servo controller in the servo drive module and the various control modules (control modules V1, V2, V3, and V4). For example, under the command of the servo controller, control module V1 of the first reversing valve can precisely adjust the direction and flow rate of the oil pump output to the first oil circuit, meeting the precise oil supply requirements under different operating conditions and improving the accuracy and stability of system operation. Regarding pressure monitoring and regulation, a first pressure sensor installed in the first oil circuit monitors the oil circuit pressure in real time. When the pressure is abnormal, the relief valve and cartridge valve are activated promptly under the control of the control module. The relief valve can overflow excess oil back to the tank, preventing damage to the equipment caused by excessive system pressure. The cartridge valve can further precisely control the oil flow rate, ensuring that the pressure in the first oil circuit remains within a stable and safe range, effectively protecting the entire hydraulic system. The connection design between the first reversing valve and the second oil circuit, as well as the installation of two second reversing valves on the second oil circuit, combined with the control of the solenoid ball valve, enables the oil to quickly and accurately reverse and switch flow directions in different operating modes. Efficient oil circuit reversing control greatly improves the operating efficiency of the hydraulic station, shortens the equipment's response time, and can quickly respond to external operational needs. The entire hydraulic station has a compact and reasonable structure. The chassis integrates key components such as the oil tank, servo drive module, and oil pump. The orderly layout of the oil circuits not only saves installation space, but also reduces the risk of leakage caused by complex pipe connections, improves system reliability and maintenance convenience, reduces operating costs, and provides stable, reliable, and efficient hydraulic power support for various industrial applications.

[0017] A servo-driven hydraulic control method, based on precise analysis of the velocity parameter v and load parameter F during the mode pre-determination phase, enables rapid and accurate activation of the appropriate mode based on different operating conditions. Accurate determination of the rapid, slow, and rapid descending modes ensures the hydraulic system operates in the most appropriate mode for various operating scenarios, significantly improving system efficiency and adaptability while avoiding resource waste and work delays caused by inappropriate mode selection. During the dynamic parameter matching phase, system parameters are automatically configured based on the selected mode, optimizing system parameters. Detailed settings for control module V1's PWM frequency and duty cycle, control module V3's holding current, and control module V4's activation response time ensure optimal hydraulic system performance in each mode. For example, the parameter settings in mode M1 meet the pressure and speed requirements for rapid descending; parameter adjustments in mode M2 address the stringent accuracy requirements for slow descending; and the parameter configuration in mode M3 effectively ensures efficiency and stability during rapid ascending. During the real-time compensation phase, closed-loop control is implemented through a sensor network, significantly enhancing system stability and reliability. The pressure fluctuation suppression algorithm rapidly adjusts the duty cycle of V1 and the valve spool opening of V4 when the main oil circuit pressure fluctuates excessively, effectively suppressing pressure fluctuations and preventing system damage from pressure shocks, thereby extending the system's service life. The anti-shock strategy, which activates promptly when displacement acceleration is excessive, effectively avoids cylinder shock by reducing the holding current of V3 and sending reverse compensation pulses, improving system operation smoothness and ensuring operational accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of a servo-driven hydraulic station according to the present invention; Figure 2 for Figure 1 A top view of the servo-driven hydraulic station; Figure 3 for Figure 1 Oil circuit diagram of servo-driven hydraulic station; Figure 4 for Figure 1 The oil circuit diagram of the first oil circuit of the servo-driven hydraulic station; Figure 5 for Figure 1 The oil circuit diagram of the second oil circuit of the servo-driven hydraulic station; Figure 6 for Figure 1 The connection diagram of the servo controller of the servo-driven hydraulic station; Figure 7 It is a flow chart of the hydraulic control method based on servo drive of the present invention.

[0019] Explanation of the accompanying drawings: chassis 1, oil tank 11, oil suction net 111, temperature sensor 112, liquid level meter 113, servo drive module 2, servo controller 21, oil pump 3, first output port 31, one-way valve 311, second output port 32, first oil circuit 4, first reversing valve 41, first pressure sensor 42, relief valve 43, cartridge valve 44, second oil circuit 5, second reversing valve 51, solenoid ball valve 52, damper 53, second pressure sensor 54, hydraulic cylinder 6, hydraulic circuit 7, return oil filter 71, air cooling device 72, quick connection module 8, quick connector 81, transition plate 82. DETAILED DESCRIPTION

[0020] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0021] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Figures 1 to 6As shown, in one embodiment of the present invention, a servo-driven hydraulic station is provided, comprising a chassis 1, a servo drive module 2, an oil pump 3, a first oil circuit 4, a second oil circuit 5, a hydraulic cylinder 6 and a hydraulic circuit 7. An oil tank 11 is provided in the chassis 1. The servo drive module 2 is provided on the chassis 1 and is driven by the oil pump 3 to drive the oil pump 3 to work. The oil pump 3 is used to connect the oil tank 11 and the first oil circuit 4 to supply oil to the first oil circuit 4. The first oil circuit 4 is provided with a first reversing valve 41, a first pressure sensor 42, a relief valve 43 and a second pressure sensor 44. The servo drive module 2 includes a first reversing valve 41 and a cartridge valve 44. The first reversing valve 41 is connected to the oil pump 3. The first pressure sensor 42 is used to detect the pressure in the first oil circuit 4. The relief valve 43 and the cartridge valve 44 are both connected to the first reversing valve 41. The output oil circuit of the first reversing valve 41 is connected to the second oil circuit 5. The hydraulic circuit 7 is connected to the return oil circuit of the second oil circuit 5. The hydraulic circuit 7 is connected to the oil tank 11 to form a circuit. The second oil circuit 5 is provided with a second reversing valve 51. The output oil circuit of the second reversing valve 51 is provided with an electromagnetic ball valve 52 connected to the hydraulic cylinder 6. Specifically, the servo drive module 2 is provided with a servo controller 21. The first reversing valve 41 is provided with a control module V1. There are two second reversing valves 51, each including a control module V2 and a control module V3. The electromagnetic ball valve 52 is provided with a control module V4. The servo controller 21 is electrically connected to the control modules V1, V2, V3, and V4. This embodiment achieves precise control of key components of the hydraulic station through the electrical connection between the servo controller 21 in the servo drive module 2 and the various control modules (control modules V1, V2, V3, and V4). For example, under the command of the servo controller 21, the control module V1 of the first reversing valve 41 precisely adjusts the direction and flow rate of oil output from the oil pump 3 to the first oil circuit 4, meeting the precise oil supply requirements under different operating conditions and improving the accuracy and stability of system operation. Regarding pressure monitoring and regulation, a first pressure sensor 42 installed in the first oil circuit 4 monitors the oil circuit pressure in real time. When pressure abnormalities occur, the relief valve 43 and the cartridge valve 44 are activated promptly under the control of the control module. The relief valve 43 drains excess oil back to the oil tank 11, preventing damage to the equipment caused by excessive system pressure. The cartridge valve 44 further precisely controls the oil flow rate, ensuring that the pressure in the first oil circuit 4 remains within a stable and safe range, effectively protecting the entire hydraulic system. The connection design between the first reversing valve 41 and the second oil circuit 5, as well as the arrangement of two second reversing valves 51 in the second oil circuit 5, combined with the control of the solenoid ball valve 52, enables rapid and accurate oil reversal and flow switching in different operating modes. Efficient oil circuit reversal control significantly improves the hydraulic station's operating efficiency, shortens the equipment's response time, and enables rapid response to external operational demands. The entire hydraulic station has a compact and rational structure.The chassis 1 integrates key components such as the oil tank 11, servo drive module 2, and oil pump 3. The oil circuits are arranged in an orderly manner, which not only saves installation space but also reduces the risk of leakage caused by complex pipeline connections, improves system reliability and maintenance convenience, reduces operating costs, and provides stable, reliable, and efficient hydraulic power support for various industrial applications.

[0023] The servo drive module 2 is a servo motor connected to the oil pump 3 via a coupling. The oil pump 3 is provided with a first output port 31 and a second output port 32. The first output port 31 is connected to the second oil circuit 5 via a first oil circuit 4, and the second output port 32 is connected to the first reversing valve 41 via a cartridge valve 44. The first output port 31 is provided with a branch oil circuit, and the branch oil circuit is provided with a check valve 311, which is connected to the first reversing valve 41. In this embodiment, the servo motor, as the servo drive module 2, with its precise control performance, can accurately adjust the speed and torque according to system requirements, thereby providing a stable and precisely controllable power input to the oil pump 3, effectively improving the operating accuracy and stability of the hydraulic system. The first output port 31 and the second output port 32 provided on the oil pump 3 have clear division of labor. The first output port 31 is connected to the second oil circuit 5 via the first oil circuit 4, which can achieve multi-channel distribution of hydraulic oil, meet the differentiated flow and pressure requirements of different working components, and enhance the adaptability of the system. The second output port 32 is connected to the first reversing valve 41 via a cartridge valve 44. The cartridge valve 44 quickly and accurately controls the flow and flow of the oil, while the first reversing valve 41 flexibly switches the direction of the oil flow. The two work together to achieve efficient switching and motion control of the actuator. The branch oil circuit and check valve 311 provided at the first output port 31 ensure unidirectional oil flow, preventing reverse flow and the adverse effects of pressure fluctuations on the system, thereby improving system reliability.

[0024] The oil tank 11 is located within the chassis 1. An oil suction screen 111 is installed within the oil tank 11, which is mounted on the oil pump 3. A temperature sensor 112 and a liquid level indicator 113 are also located within the oil tank 11. The chassis 1 is also equipped with a refueling port for refueling the oil tank 11. In this embodiment, the oil suction screen 111, mounted on the oil pump 3, effectively filters the oil entering the oil pump 3, intercepting impurities in the oil and preventing them from entering the precision components of the hydraulic system. This significantly reduces the probability of failure of key components such as the oil pump 3 and the valve block due to wear and tear caused by impurities, extending the service life of these components and improving the stability and reliability of the entire hydraulic system. The temperature sensor 112 within the oil tank 11 monitors the oil temperature in real time, providing accurate data for the system's thermal management. Based on this data, the cooling system can be adjusted to ensure that the oil temperature remains within the appropriate operating range. This prevents problems such as decreased oil viscosity and increased system leakage caused by excessively high oil temperature, thereby ensuring the transmission efficiency and control accuracy of the hydraulic system.

[0025] A quick-connect module 8 is provided between the first oil circuit 4 and the second oil circuit 5. The quick-connect module 8 includes a quick connector 81 and a transition plate 82. The transition plate 82 is used to connect to the second oil circuit 5, and the quick connector 81 is used to connect the first oil circuit 4 and the second oil circuit 5. Specifically, the second oil circuit 5 is provided with a damper 53 and a second pressure sensor 54. The second pressure sensor 54 is used to detect the oil pressure in the second oil circuit 5, and the damper 53 is used to generate damping in the second oil circuit 5. In this embodiment, the use of the quick-connect module 8 greatly improves the convenience and efficiency of the hydraulic station's oil circuit connection. The combination of the quick connector 81 and the transition plate 82 enables the first oil circuit 4 and the second oil circuit 5 to be quickly and securely connected, reducing the time and cost of oil circuit installation and disassembly, improving the efficiency of equipment maintenance and overhaul, and reducing the risk of oil circuit damage that may occur due to frequent connection operations. The provision of the damper 53 and the second pressure sensor 54 in the second oil circuit 5 further optimizes the performance of the hydraulic station. Second pressure sensor 54 accurately detects the oil pressure in second oil circuit 5 in real time, providing the system with precise pressure data. This allows the servo drive system to precisely adjust the oil pressure based on the actual conditions, ensuring stable and reliable operation of the entire hydraulic system. The damper 53 effectively dampens second oil circuit 5, buffering pressure fluctuations and shocks that may occur during hydraulic system operation. This prevents damage to system components caused by sudden pressure changes, extends the service life of various hydraulic station components, and improves the stability and reliability of the entire hydraulic system.

[0026] The hydraulic circuit 7 includes an oil return filter 71, which is connected to the fuel tank 11. On one side of the oil return filter 71, there is an air cooling device 72, which is used to cool the liquid filtered by the oil return filter 71. In this embodiment, the oil return filter 71 is connected to the fuel tank 11, which can effectively filter the hydraulic oil flowing back from the system to the fuel tank 11, remove impurities, wear particles, etc. generated during the operation of the system, and prevent these pollutants from entering the hydraulic system again, thereby extending the service life of each hydraulic component in the system and reducing the probability of failures caused by impurity wear. The air cooling device 72 provided on one side of the oil return filter 71 cools the filtered liquid. When the hydraulic system is working, the oil temperature will rise due to various energy losses. Excessive oil temperature will affect the viscosity and performance of the oil, reducing the working efficiency and stability of the system.

[0027] The servo controller 21 controls the servo drive module 2 to start, and the control modules V1, V3, and V4 are turned on to drive the hydraulic cylinder 6 to press down quickly; the control modules V3 and V4 are turned on to drive the hydraulic cylinder 6 to press down slowly; the control modules V1, V2, and V4 are turned on to drive the hydraulic cylinder 6 to rise quickly. In this embodiment, by precisely controlling the start of the servo drive module 2 through the servo controller 21, precise control of the movement of the hydraulic cylinder 6 can be achieved. When the control modules V1, V3, and V4 are turned on to drive the hydraulic cylinder 6 to press down quickly, the hydraulic cylinder 6 can quickly reach the specified position, greatly improving the working efficiency and meeting the working conditions with high speed requirements, such as some processing links that require rapid prototyping or positioning. When the control modules V3 and V4 are turned on to drive the hydraulic cylinder 6 to press down slowly, it can ensure the smoothness and accuracy of the pressing process in scenarios that require fine operation, reducing the risk of errors or equipment damage caused by excessive speed. As for the control modules V1, V2, and V4 being turned on to drive the hydraulic cylinder 6 to rise quickly and return to the initial position quickly, it prepares for the next work cycle and shortens the overall work cycle.

[0028] Refer to Figures 1 to 7 As shown, a hydraulic control method based on servo drive includes a hydraulic station based on servo drive, and the hydraulic control method includes the following steps: Step S1, mode prediction stage: After the servo controller 21 receives the upper computer instruction through the CAN bus, it executes: parsing the speed parameter v and the load parameter F in the instruction. When v≥50 and F≥100, the fast downward pressing mode is activated. When 10<v<50 and 50<F<100, the slow downward pressing mode is activated. When v≥80 and F<50, the fast upward rising mode is activated; Step S2, dynamic parameter matching stage: Automatically configure parameters according to the selected mode: In M1 mode: set the PWM frequency f1 of control module V1 to 10kHz±5%, duty cycle D1 to 85%±3%; set the holding current I3 of control module V3 to 1.2A±0.1A; and set the turn-on response time t4 of control module V4 to 5ms or less. In M2 mode: set V1's PWM frequency f1 to 5kHz±5%, duty cycle D1 to 60%±3%; V3's holding current I3 to 0.8A±0.1A; V4's turn-on response time t4 to 15-20ms; In M3 mode: set V1's PWM frequency f1 = 15kHz±5%, duty cycle D1 = 95%±3%; V2's pulse width W2 = 200μs±10%; V4's valve core opening θ4 = 90%±2%; Step S3, real-time compensation phase: Closed-loop control is performed through the sensor network: the main oil circuit pressure P is collected through the first pressure sensor 42, and the real-time position L is collected through the cylinder displacement sensor; when |dP / dt| ≥ 20 bar / s, the pressure fluctuation suppression algorithm is triggered: Adjust the duty cycle of V1 to ΔD1 = Kp*(dP / dt)+Ki*∫(dP / dt)dt, where Kp=0.5% / bar / s, Ki=0.2% / bar; and simultaneously adjust the valve core opening of V4 to θ4=θ4_initial-0.8*(dP / dt). When the displacement acceleration a=d²L / dt²≥500mm / s², the anti-shock strategy is activated: the holding current of V3 is reduced by 30% within 10ms, and a reverse compensation pulse is sent to V2 with a pulse width W2_comp=50μs±5%.

[0029] In the above-described embodiment, during the mode pre-determination phase, precise analysis of the velocity parameter v and the load parameter F enables rapid and accurate activation of the corresponding mode based on different operating conditions. Accurate determination of the rapid, slow, and rapid descending modes ensures that the hydraulic system operates in the most appropriate mode for various operating scenarios, significantly improving system efficiency and adaptability and avoiding resource waste and work delays caused by improper mode selection. During the dynamic parameter matching phase, system parameters are automatically configured based on the selected mode, optimizing system parameters. Detailed settings for parameters such as the PWM frequency and duty cycle of control module V1, the holding current of control module V3, and the turn-on response time of control module V4 in different modes ensure optimal hydraulic system performance in each mode. For example, the parameter settings in mode M1 meet the pressure and speed requirements for rapid descending; the parameter adjustments in mode M2 address the stringent accuracy requirements for slow descending; and the parameter configuration in mode M3 effectively ensures efficiency and stability during rapid ascending. During the real-time compensation phase, closed-loop control is implemented through a sensor network, significantly enhancing system stability and reliability. The pressure fluctuation suppression algorithm rapidly adjusts the duty cycle of V1 and the valve spool opening of V4 when the main oil circuit pressure fluctuates excessively, effectively suppressing pressure fluctuations and preventing system damage from pressure shocks, thereby extending the system's service life. The anti-shock strategy, which activates promptly when displacement acceleration is excessive, effectively avoids cylinder shock by reducing the holding current of V3 and sending reverse compensation pulses, improving system operation stability and ensuring operational accuracy.

[0030] The following cross-domain control policies are also included: Thermal coupling control: The oil temperature T is collected in real time through the temperature sensor 112; the thermal balance equation is established: Q_gen=αPv+βF² / R Q_cool=γ(T-T_amb)*v_fan Among them, α=0.015W / (bar·mm / s), β=0.0008W / (kN²·Ω), γ=0.12W / (℃·m / s) c) When T≥65℃, execute: Increase the speed of the air cooling device 72 to N_fan=2000+50*(T-65)rpm; Add temperature compensation current ΔI3=0.05*(T-60)A to the V3 control loop; Limit the maximum speed of the servo motor ω_max=ω_nom*[1-0.015*(T-60)] Fluid-solid coupling vibration suppression: The vibration spectrum data of the oil block is collected through the acceleration sensor; when the vibration amplitude A ≥ 0.5g in the 200-500Hz frequency band is detected: Inject anti-phase harmonics into the PWM signal of V1, harmonic order n=3,5,7 Adjust the valve core movement trajectory of V4 as follows: θ(t)=θ0+Δθsin(2πft+φ) Where f = vibration frequency ± 10 Hz, Δθ = 0.5°~1.5°, φ = 180°±5°; At the same time, the active control mode of the hydraulic damper 53 is activated, applying a damping force: F_damp=Kdv_pipe+Cd*dv_pipe / dt Where Kd=50N·s / m, Cd=20N·s² / m².

[0031] In the above-mentioned embodiment, regarding thermal coupling control, by collecting oil temperature in real time and regulating it according to the heat balance equation, when the oil temperature is ≥65°C, targeted adjustments are made to the speed of the air cooling device 72, the temperature compensation current of the V3 control loop, and the maximum speed of the servo motor. This can effectively maintain the oil temperature within a reasonable range, avoiding problems such as decreased hydraulic oil viscosity and increased component wear due to excessively high oil temperature, thereby improving the stability and reliability of the hydraulic system and extending the service life of the equipment. In the fluid-solid coupling vibration suppression strategy, vibration spectrum data is collected and corresponding measures are taken when the vibration amplitude in a specific frequency band exceeds the standard, such as injecting anti-phase harmonics, adjusting the valve core motion trajectory, and activating the active control mode of the hydraulic damper 53 to apply damping force. This can effectively reduce the vibration of the oil circuit block, reduce the noise and pipeline fatigue damage caused by vibration, and improve the overall stability and safety of the hydraulic station operation.

[0032] The following fault response mechanisms are also included: Sensor fault diagnosis: Perform double calibration on the pressure sensor: The difference between the main sensor P1 and the redundant sensor P2 |ΔP|=|P1-P2|; When |ΔP|≥5bar for 100ms, the sensor health assessment is activated: Send a test pulse signal to V4 and observe the response delay of P1 / P2. If the delay difference is ≥ 2ms, determine that the sensor is faulty and switch to the backup channel. Self-calibration of the oil temperature sensor: Perform zero point calibration every 24 hours: T_cal=T_raw-0.5*(T_env-25℃) When dT / dt≥10℃ / s, the thermocouple cold junction compensation algorithm is activated; Actuator fault recovery: When a V1 driver abnormality is detected: Transfer control to the backup PWM generator within 50ms; At the same time, adjust the duty cycle compensation of V2 to ΔD2 = 1.2*(1-D1 / D1_nom); When V3 is stuck: apply a sweep frequency signal with increasing amplitude to the V3 coil. If the valve core does not reset, establish a reverse oil pressure ΔP=20-30bar through V2 for mechanical unlocking.

[0033] In the above embodiment, in terms of sensor fault diagnosis, the double calibration and health assessment of the pressure sensor can accurately identify the faulty sensor, quickly switch to the backup channel, ensure the accuracy and reliability of the pressure data, avoid system loss of control due to pressure misjudgment, and improve the stability of system operation. The self-calibration mechanism of the oil temperature sensor ensures the accuracy of temperature measurement, effectively reduces the impact of ambient temperature on the measurement results, and enables the hydraulic station to operate stably under different working conditions. The actuator fault recovery strategy, when the V1 drive is abnormal, quickly transfers control and adjusts the V2 duty cycle compensation to maintain the continuity of the system power output; for the handling method of V3 jamming, mechanical unlocking is performed by applying a sweep frequency signal and establishing reverse oil pressure, which can promptly eliminate the jamming fault, prevent the actuator from failing for a long time, extend the service life of the equipment, and greatly improve the overall reliability and fault response capability of the servo-driven hydraulic station.

[0034] The above embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A servo-driven hydraulic station, characterized by: The hydraulic system comprises a chassis, a servo drive module, an oil pump, a first oil circuit, a second oil circuit, a hydraulic cylinder and a hydraulic circuit. The chassis is provided with an oil tank. The servo drive module is provided on the chassis and is connected to the oil pump drive to drive the oil pump to work. The oil pump is used to connect the oil tank and the first oil circuit to supply oil to the first oil circuit. The first oil circuit is provided with a first reversing valve, a first pressure sensor, a relief valve and a cartridge valve. The first reversing valve is used to connect the oil pump. The first pressure sensor is used to detect the pressure of the first oil circuit. The relief valve and the cartridge valve are both connected to the first reversing valve. The output oil circuit of the first reversing valve is connected to the second oil circuit, the hydraulic circuit is connected to the return oil circuit of the second oil circuit, and the hydraulic circuit is connected to the oil tank to form a circuit. The second oil circuit is provided with a second reversing valve. The output oil circuit of the second reversing valve is provided with an electromagnetic ball valve connected to the hydraulic cylinder. The servo drive module is provided with a servo controller, the first reversing valve is provided with a control module V1, two second reversing valves are provided, and the two second reversing valves respectively include a control module V2 and a control module V3, and the electromagnetic ball valve is provided with a control module V4. The servo controller is electrically controlled and connected to the control module V1, the control module V2, the control module V3 and the control module V4.

2. The servo-driven hydraulic station according to claim 1, characterized in that: The servo drive module is a servo motor, which is connected to an oil pump through a coupling. The oil pump is provided with a first output port and a second output port. The first output port is connected to the second oil circuit through a first oil circuit, and the second output port is connected to the first reversing valve through a cartridge valve. The first output port is provided with a branch oil circuit, and the branch oil circuit is provided with a one-way valve, which is connected to the first reversing valve.

3. The servo-driven hydraulic station according to claim 1, characterized in that: The oil tank is arranged in the chassis, an oil suction net is arranged in the oil tank, the oil suction net is arranged on the oil pump, a temperature sensor and a liquid level meter are arranged in the oil tank, and the chassis is provided with a refueling port, and the refueling port is used to refuel the oil tank.

4. The servo-driven hydraulic station according to claim 1, characterized in that: A quick connection module is provided between the first oil circuit and the second oil circuit. The quick connection module includes a quick connector and a transition plate. The transition plate is used to connect the second oil circuit. The quick connector is used to connect the first oil circuit and the second oil circuit.

5. The servo-driven hydraulic station according to claim 1, characterized in that: The second oil circuit is provided with a damper and a second pressure sensor, the second pressure sensor is used to detect the oil pressure of the second oil circuit, and the damper is used to generate damping in the second oil circuit.

6. The servo-driven hydraulic station according to claim 1, characterized in that: The hydraulic circuit includes an oil return filter, which is connected to the oil tank. An air cooling device is provided on one side of the oil return filter, and the air cooling device is used to cool the liquid filtered by the oil return filter.

7. The servo-driven hydraulic station according to claim 1, characterized in that: The servo controller controls the servo drive module to start, and the control module V1, control module V3 and control module V4 are turned on to drive the hydraulic cylinder to press down quickly; the control module V3 and control module V4 are turned on to drive the hydraulic cylinder to press down slowly; the control module V1, control module V2 and control module V4 are turned on to drive the hydraulic cylinder to rise quickly.

8. A hydraulic control method based on servo drive, characterized in that: The servo-driven hydraulic station according to any one of claims 1 to 7, wherein the hydraulic control method comprises the following method: Step S1, Mode Prediction Phase: After receiving the host computer instruction through the CAN bus, the servo controller executes: Parse the speed parameter v and load parameter F in the instruction. When v≥50 and F≥100, activate the fast downward pressure mode. When 10<v<50 and 50<F<100, activate the slow downward pressure mode. When v≥80 and F<50, activate the fast upward mode; Step S2, Dynamic Parameter Matching Phase: Automatically configure parameters according to the selected mode: In M1 mode: Set the PWM frequency f1 of control module V1 to 10kHz±5%, duty cycle D1 to 85%±3%; the holding current I3 of control module V3 to 1.2A±0.1A; the turn-on response time t4 of control module V4 to t4≤5ms; In M2 mode: Set the PWM frequency f1 of V1 to 5kHz±5%, duty cycle D1 to 60%±3%; the holding current I3 of V3 to 0.8A±0.1A; the turn-on response time t4 of V4 to 15 - 20ms; In M3 mode: Set the PWM frequency f1 of V1 to 15kHz±5%, duty cycle D1 to 95%±3%; the pulse width W2 of V2 to 200μs±10%; the spool opening θ4 of V4 to 90%±2%; Step S3, Real-time Compensation Phase: Perform closed-loop control through the sensor network: Collect the main oil circuit pressure P through the first pressure sensor, and collect the real-time position L through the oil cylinder displacement sensor; When |dP / dt|≥20bar / s, trigger the pressure fluctuation suppression algorithm: Adjust the duty cycle of V1, ΔD1 = Kp*(dP / dt)+Ki*∫(dP / dt)dt, where Kp = 0.5% / bar / s, Ki = 0.2% / bar; Synchronously adjust the spool opening of V4, θ4 = θ4_initial - 0.8*(dP / dt) When the displacement acceleration a = d²L / dt²≥500mm / s², activate the anti-shock strategy: Reduce the holding current of V3 by 30% within 10ms, and send a reverse compensation pulse to V2, pulse width W2_comp = 50μs±5%.

9. The servo-driven hydraulic control method according to claim 8, characterized in that: It also includes the following cross-domain control strategies: Thermal-mechanical Coupling Control: Collect the oil temperature T in real time through the temperature sensor; Establish the heat balance equation: Q_gen = αPv + βF² / R Q_cool = γ(T - T_amb)*v_fan where α = 0.015W / (bar·mm / s), β = 0.0008W / (kN²·Ω), γ = 0.12W / (℃·m / s) c) When T≥65℃, execute: Increase the speed of the air-cooling device to N_fan = 2000 + 50*(T - 65)rpm; Superimpose the temperature compensation current ΔI3 = 0.05*(T - 60)A in the V3 control loop; Limit the maximum speed of the servo motor ω_max = ω_nom*[1 - 0.015*(T - 60)] Fluid-structure Coupling Vibration Suppression: Collect the vibration spectrum data of the oil circuit block through the acceleration sensor; When the vibration amplitude A in the 200 - 500Hz frequency band is detected to be A≥0.5g: Inject anti-phase harmonics into the PWM signal of V1, harmonic order n=3,5,7 Adjust the valve core movement trajectory of V4 as follows: θ(t)=θ0+Δθsin(2πft+φ) Where f = vibration frequency ± 10 Hz, Δθ = 0.5°~1.5°, φ = 180°±5°; At the same time, the active control mode of the hydraulic damper is activated, applying the damping force: F_damp=Kdv_pipe+Cd*dv_pipe / dt Where Kd=50N·s / m, Cd=20N·s² / m².

10. The servo-driven hydraulic control method according to claim 8, characterized in that: The following fault response mechanisms are also included: Sensor fault diagnosis: Perform double calibration on the pressure sensor: The difference between the main sensor P1 and the redundant sensor P2 |ΔP|=|P1-P2|; When |ΔP|≥5bar for 100ms, the sensor health assessment is activated: Send a test pulse signal to V4 and observe the response delay of P1 / P2. If the delay difference is ≥ 2ms, determine that the sensor is faulty and switch to the backup channel. Self-calibration of the oil temperature sensor: Perform zero point calibration every 24 hours: T_cal=T_raw-0.5*(T_env-25℃) When dT / dt≥10℃ / s, the thermocouple cold junction compensation algorithm is activated; Actuator fault recovery: When a V1 driver abnormality is detected: Transfer control to the backup PWM generator within 50ms; At the same time, adjust the duty cycle compensation of V2 to ΔD2 = 1.2*(1-D1 / D1_nom); When V3 is stuck: apply a sweep frequency signal with increasing amplitude to the V3 coil. If the valve core does not reset, establish a reverse oil pressure ΔP=20-30bar through V2 for mechanical unlocking.

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