Method and experimental device for precise position control of a hydraulic cylinder

Abstract

The present disclosure provides a method and experimental device for precise position control of a hydraulic cylinder. The device includes a control oil supply module, a test module, a collection module, and a control module. The control oil supply module provides hydraulic oil for the hydraulic cylinder under different characteristic parameters. The test module includes a reversing valve, a vibration unit, and a load. The reversing valve receives control instructions from the control module to control the hydraulic cylinder to push and pull the load. The vibration unit carries the hydraulic cylinder and provides different working conditions of the vibration state for the hydraulic cylinder. The load is connected to the hydraulic cylinder. The collection module collects the characteristic parameters of the hydraulic oil and transmits them to the control module. The control module obtains a training data set based on the vibration state under different working conditions, the characteristic parameters of the hydraulic oil, and the set action advance. The neural network model is trained using the training data set to obtain an action advance model. According to the device of the present disclosure, the control precision of the existing technology for the position of the hydraulic cylinder is improved.

Description

Technical Field

[0001] This disclosure relates to the field of hydraulic cylinder position control in underground coal mine hydraulic supports, and in particular to a method and experimental apparatus for precise position control of hydraulic cylinders. Background Technology

[0002] Hydraulic supports are crucial support equipment in coal mining, and their rapid and accurate support is essential for safe and efficient mining. Precise position control is urgently needed for the pulling and pushing actions of the hydraulic cylinders and the inclination angle control of the tail beam of the top coal caving support. The accuracy of the pulling and pushing actions directly affects the straightness of the working face, thus impacting its continuous automatic advancement, and is one of the key challenges in achieving intelligent mining. Extra-thick coal seams can be mined using the top coal caving process. Precise control of the tail beam's swing angle can reduce the mixing of gangue and decrease the workload of subsequent coal washing. However, the severe vibrations caused by falling coal and gangue can seriously affect the accuracy of the hydraulic cylinder position control.

[0003] Currently, hydraulic support following and relocation generally adopts automatic following based on time sequence. Chinese patent application CN110847943A discloses a timing planning method for hydraulic support following and relocation actions in coal mining. This method considers the time relationship constraints between various support actions and plans the timing of the actions, but it still struggles to solve problems such as incomplete relocation and slow speed. Chinese patent application CN105569703A discloses a precise control system and method for hydraulic support relocation and pushing. This method proposes a lifting logic and a stop-and-lower valve to achieve precise position control, but this leads to a slower cylinder movement speed. For precise position control of hydraulic cylinders, other industries typically use continuously adjustable control elements such as servo valves, proportional valves, and proportional variable pumps, or high-speed switching valves that allow for high-speed fine-tuning. However, due to the harsh underground environment, the high impurity content of emulsions, and the defects in the lifespan and reliability of such valves, their application underground is limited. Therefore, the accuracy of existing control methods for hydraulic cylinder position control still needs improvement. Summary of the Invention

[0004] This disclosure aims to at least partially address one of the technical problems in the related art. To this end, one objective of this disclosure is to provide an experimental apparatus for precise position control of a hydraulic cylinder, with the primary objective of improving the accuracy of hydraulic cylinder position control in the prior art.

[0005] The second objective of this disclosure is to provide a method for precise position control of a hydraulic cylinder.

[0006] To achieve the above objectives, a first aspect of this disclosure provides an experimental apparatus for precise position control of a hydraulic cylinder, comprising an oil supply and control module, a testing module, a data acquisition module, and a control module, wherein...

[0007] The oil supply and control module is used to provide hydraulic oil with different characteristic parameters to the hydraulic cylinder;

[0008] The test module includes a reversing valve, a vibration unit, and a load. The reversing valve receives control commands from the control module to reverse the direction of the hydraulic cylinder and control the hydraulic cylinder to push and pull the load. The vibration unit supports the hydraulic cylinder and provides vibration states for the hydraulic cylinder under different working conditions. The load is connected to the hydraulic cylinder.

[0009] The acquisition module is used to acquire the characteristic parameters of the hydraulic oil and transmit them to the control module;

[0010] The control module is used to obtain a training dataset based on the vibration state under different working conditions, the characteristic parameters of the hydraulic oil, and the set action lead, and to use the training dataset to train a neural network model to obtain an action lead model.

[0011] In one embodiment of this disclosure, the acquisition module is further configured to acquire hydraulic cylinder stroke parameters, and the control module is further configured to, after obtaining the action advance model, input the characteristic parameters and vibration state of the hydraulic oil acquired in real time into the action advance model to output the action advance, generate the control command based on the output action advance, target position and hydraulic cylinder stroke parameters, obtain the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than a preset error threshold, the action advance model is optimal; otherwise, the action advance model is optimized.

[0012] In one embodiment of this disclosure, the hydraulic oil supply and control module includes a variable pump, a temperature-controlled oil tank, and a filter. The temperature-controlled oil tank is used to provide hydraulic oil at different temperatures, the variable pump is used to adjust the pressure and flow rate of the hydraulic oil, and the filter is used to adjust the filtration accuracy of the hydraulic oil. The characteristic parameters include the temperature, flow rate, and pressure of the hydraulic oil.

[0013] In one embodiment of this disclosure, the vibration unit includes a base and a vibrator. The base is used to fix a hydraulic cylinder. The hydraulic cylinder is fixed to the base by studs. The piston rod of the hydraulic cylinder is fixed to the load. The vibrator is used to provide vibration states of different working conditions for the hydraulic cylinder. The vibration states include vibration amplitude, vibration frequency and vibration acceleration.

[0014] In one embodiment of this disclosure, the acquisition module includes a flow sensor, a pressure sensor, a temperature sensor, and a stroke sensor. The flow sensor is used to detect the flow rate of hydraulic oil at the directional valve. The pressure sensor is used to detect the pressure of hydraulic oil at the directional valve, the oil pressure in the rodless chamber of the hydraulic cylinder, and the oil pressure in the rod chamber. The temperature sensor is used to detect the temperature of hydraulic oil in the temperature-controlled oil tank. The stroke sensor is used to measure the stroke parameters of the hydraulic cylinder, including the current extension amount of the piston rod of the hydraulic cylinder.

[0015] In one embodiment of this disclosure, the flow sensor is a turbine flow sensor, the stroke sensor is a draw-rope stroke sensor, and the directional valve is a solenoid directional valve.

[0016] In one embodiment of this disclosure, the control module includes a controller and a host computer. The controller is used to receive the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder collected by the acquisition module and upload them to the host computer, and obtain the motion advance model from the host computer. The host computer is used to obtain the target position, the training dataset and the motion advance model, and send the target position to the controller and burn the motion advance model to the controller.

[0017] To achieve the above objectives, a second aspect of this disclosure also provides a method for precise position control of a hydraulic cylinder. This method employs an action lead model obtained from the experimental apparatus for precise position control of a hydraulic cylinder according to any of the above embodiments to perform precise position control, and includes:

[0018] The experimental device is run according to preset parameters to obtain the vibration state of the hydraulic cylinder under different working conditions, the characteristic parameters of the hydraulic oil, and the set action advance to generate a training dataset. The neural network model is trained using the training dataset to obtain the action advance model.

[0019] In the actual working condition of the hydraulic cylinder, the characteristic parameters of the hydraulic oil and the vibration state under the actual working condition are collected in real time, and the position of the hydraulic cylinder is calculated. The characteristic parameters of the hydraulic oil collected in real time and the vibration state under the actual working condition are input into the action advance model to output the action advance. The hydraulic cylinder is position controlled based on the calculated position of the hydraulic cylinder and the output action advance.

[0020] In one embodiment of this disclosure, after obtaining the action advance model, the method further includes optimizing the action advance model. The optimization process includes: running the experimental device under random parameters, collecting the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder in real time, inputting the real-time collected characteristic parameters and the obtained vibration state under the corresponding working condition into the action advance model to output the action advance, controlling the hydraulic cylinder to push and pull the load based on the output action advance, target position and hydraulic cylinder stroke parameters; obtaining the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than a preset error threshold, then the optimal action advance model is obtained.

[0021] In one embodiment of this disclosure, obtaining the motion error based on the hydraulic cylinder stroke parameters, and obtaining the optimal motion advance model if the motion error is less than a preset error threshold, includes: obtaining at least three consecutive hydraulic cylinder stroke parameters and calculating the difference between adjacent hydraulic cylinder stroke parameters; if multiple differences are all less than a preset difference, obtaining the end-of-run position based on the at least three consecutive hydraulic cylinder stroke parameters; obtaining the motion error based on the end-of-run position and the target position; and obtaining the optimal motion advance model if the motion error is less than the preset error threshold.

[0022] In one or more embodiments of this disclosure, the oil control module provides hydraulic oil with different characteristic parameters to the hydraulic cylinder; the testing module includes a reversing valve, a vibration unit, and a load. The reversing valve receives control commands from the control module to reverse the direction of the hydraulic cylinder to push and pull the load; the vibration unit carries the hydraulic cylinder and provides vibration states for the hydraulic cylinder under different working conditions; the load is connected to the hydraulic cylinder; the acquisition module acquires the characteristic parameters of the hydraulic oil and transmits them to the control module; the control module obtains a training dataset based on the vibration states under different working conditions, the characteristic parameters of the hydraulic oil, and the set action lead, and uses the training dataset to train a neural network model to obtain an action lead model. In this case, by comprehensively considering the vibration states under different working conditions and the characteristic parameters of the hydraulic oil to obtain the action lead model, without changing the existing hydraulic cylinder position control system, the action lead model is used to calibrate the hydraulic cylinder position obtained by the hydraulic cylinder position control system in the actual environment, thereby improving the control accuracy of the hydraulic cylinder position in the prior art.

[0023] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1A block diagram of an experimental apparatus for precise position control of a hydraulic cylinder provided in an embodiment of this disclosure is shown.

[0026] Figure 2 This diagram illustrates the structure of an experimental apparatus for precise position control of a hydraulic cylinder according to an embodiment of the present disclosure.

[0027] Figure 3 This diagram illustrates a flowchart of an experimental method for obtaining a motion lead model according to an embodiment of the present disclosure.

[0028] Figure 4 A flowchart illustrating a method for precise position control of a hydraulic cylinder provided in an embodiment of this disclosure is shown.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1—Oil supply and control module; 2—Test module; 3—Acquisition module; 4—Control module; 5—Power supply module; 6—Hydraulic cylinder; 1-1—Temperature-controlled oil tank; 1-2—Variable pump; 1-3—Filter; A—First working oil port; B—Second working oil port; P—Oil inlet; R—Oil return port; 2-1—Reversing valve; 2-2—Load; 2-3—Base; 2-4—Vibration machine; 3-1—Flow sensor; 3-2—Pressure sensor; 3-3—Temperature sensor; 3-4—Stroke sensor; 4-1—Controller; 4-2—Host computer. Detailed Implementation

[0031] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this disclosure as detailed in the appended claims.

[0032] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined. It should also be understood that the term "and / or" as used in this disclosure refers to and includes any or all possible combinations of one or more associated listed items.

[0034] It should be understood that the described embodiments are merely some, not all, of the embodiments of this disclosure. To more clearly illustrate this disclosure, numerous technical details are described in the following specific embodiments. Those skilled in the art should understand that this disclosure can be implemented even without some of these details. Furthermore, to highlight the inventive intent of this disclosure, some methods, means, components, and applications well-known to those skilled in the art are not described in detail; however, this does not affect the implementation of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0035] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0036] This disclosure provides a method and experimental apparatus for precise position control of a hydraulic cylinder, with the main objective of improving the accuracy of hydraulic cylinder position control (i.e., the actuation accuracy of the hydraulic cylinder) in the prior art. The experimental apparatus for precise position control of the hydraulic cylinder disclosed herein can be simply referred to as the experimental apparatus.

[0037] In the first embodiment, Figure 1 A block diagram of an experimental apparatus for precise position control of a hydraulic cylinder provided in an embodiment of this disclosure is shown. Figure 2 This diagram illustrates the structure of an experimental apparatus for precise position control of a hydraulic cylinder, as provided in an embodiment of this disclosure. Figure 1 As shown, the experimental device for precise position control of the hydraulic cylinder includes an oil supply and control module 1, a test module 2, a data acquisition module 3, and a control module 4. The control module 4 is connected to the oil supply and control module 1, the test module 2, and the data acquisition module 3, respectively.

[0038] In this embodiment, the oil supply control module 1 is used to provide hydraulic oil with different characteristic parameters to the hydraulic cylinder. These characteristic parameters may include, but are not limited to, parameters such as the temperature, flow rate, and pressure of the hydraulic oil.

[0039] In some embodiments, such as Figure 2 As shown, the oil supply and control module 1 includes a temperature-controlled oil tank 1-1, a variable pump 1-2, and a filter 1-3.

[0040] In some embodiments, the temperature-controlled oil tank is an oil tank with oil temperature control function. The temperature-controlled oil tank 1-1 is used to supply hydraulic oil at different temperatures. This allows for the investigation of the effect of oil temperature on positioning accuracy.

[0041] In some embodiments, the variable pump 1-2 is used to regulate the pressure and flow rate of hydraulic oil. Specifically, the variable pump 1-2 can draw hydraulic oil from the temperature-controlled oil tank 1-1, regulate the pressure and flow rate of the drawn hydraulic oil, and then discharge the regulated hydraulic oil through a high-pressure hose to the hydraulic cylinder to provide power to the hydraulic cylinder.

[0042] In some embodiments, filters 1-3 are used to adjust the filtration accuracy of the hydraulic oil. Specifically, filters 1-3 can adjust the filtration accuracy of the hydraulic oil output from the temperature-controlled oil tank 1-1. In this case, the use of filters serves two purposes: to simulate real downhole production conditions and to protect the experimental setup.

[0043] In some embodiments, the variable pump 1-2, filter 1-3, temperature-controlled oil tank 1-1, safety valve and accessories can be placed inside the factory building, and the hydraulic oil can be connected to the outdoor test bench through pipelines (e.g., high-pressure hoses). In addition, different pressures and flow rates can be achieved by adjusting the handwheel.

[0044] In some embodiments, such as Figure 2 As shown, test module 2 includes a reversing valve 2-1, a vibration unit, and a load 2-2.

[0045] In some embodiments, the reversing valve 2-1 is used to receive control commands from the control module 4 to reverse the direction in order to control the hydraulic cylinder to push and pull the load.

[0046] In some embodiments, the directional control valve may be an electromagnetic directional control valve. Specifically, the electromagnetic directional control valve can receive control commands from the controller 4-1 (described later) to complete the directional control action, thereby controlling the hydraulic cylinder 6 to perform push-pull actions. The electromagnetic directional control valve and the controller may employ a common anode control method, and the electromagnetic directional control valve communicates with the controller via one power line and two signal lines.

[0047] In some embodiments, such as Figure 2 As shown, the reversing valve 2-1 includes an oil inlet P, an oil return port R, a first working oil port A, and a second working oil port B. The oil inlet P is connected to the variable pump 1-2, the oil return port R is connected to the temperature control oil tank 1-1, and the first oil port A and the second oil port B are connected to the actuator (i.e., the hydraulic cylinder) through high-pressure hoses.

[0048] In some embodiments, the vibration unit is used to support the hydraulic cylinder and provide vibration states for the hydraulic cylinder under different working conditions.

[0049] In some embodiments, such as Figure 2 As shown, the vibration unit includes a base 2-3 and a vibrator 2-4.

[0050] In some embodiments, the base 2-3 can be used to fix the hydraulic cylinder 6. The hydraulic cylinder 6 is fixed to the base 2-3 by studs, and the piston rod of the hydraulic cylinder 6 is fixed to the load 2-2. Specifically, the hydraulic cylinder 6 is placed above the vibrator 2-4. The rear cylinder cover of the hydraulic cylinder 6 is fixed to the base 2-3 by studs, the bottom of the hydraulic cylinder 6 is fixed to the base 2-3 by pins, the base 2-3 is fixed to the ground by expansion bolts, and the piston rod is fixed to the load 2-2.

[0051] In some embodiments, the vibratory machines 2-4 are used to provide different vibration states for the hydraulic cylinder 6 under different operating conditions. These vibration states may include, but are not limited to, vibration amplitude, vibration frequency, and vibration acceleration. Thus, by setting vibrations with different amplitudes, frequencies, and accelerations, the actual operating conditions of the hydraulic cylinder are simulated.

[0052] In some embodiments, such as Figure 2 As shown, load 2-2 is connected to hydraulic cylinder 6. Load 2-2 is used to simulate the actual push-pull state of hydraulic cylinder 6.

[0053] In some embodiments, the load 2-2 is fixed to the piston rod by a pin.

[0054] In some embodiments, load 2-2 can be a variable load. For example, two 5t iron blocks can be used as a variable load in the experiment. This facilitates the simulation of the real-world pushing and pulling action of a hydraulic cylinder.

[0055] In this embodiment, the hydraulic cylinder 6 serves as the actuating element during the experiment, enabling the pushing and pulling of the load and providing action assurance for the generation of experimental data. During the experiment, the hydraulic cylinder 6 and the experimental apparatus of this disclosure constitute the experimental system.

[0056] In some embodiments, a double-acting single-rod hydraulic cylinder with a stroke of 500 mm can be used in the experiment.

[0057] In this embodiment, the hydraulic cylinder operates under different oil pressure, flow rate, temperature, filtration accuracy, and vibration conditions through the oil supply and control module 1 and the testing module 2. That is, the real working scenario of the hydraulic cylinder is simulated by using devices such as temperature control oil tank 1-1, variable pump 1-2, filter 1-3, variable load, and vibration machine 2-4. This provides the basic conditions for studying the mapping relationship between various environmental parameters (including characteristic parameters and vibration parameters) and action lead. During the operation, the hydraulic cylinder acts as an actuator to push and pull the load and generates a large amount of sample data. After being collected by the acquisition module 3, a training dataset is generated for training the neural network algorithm.

[0058] In this embodiment, the acquisition module 3 is used to acquire the characteristic parameters of the hydraulic oil and transmit them to the control module 4.

[0059] In this embodiment, the acquisition module 3 is also used to acquire hydraulic cylinder stroke parameters and transmit them to the control module 4.

[0060] In some embodiments, such as Figure 2 As shown, the acquisition module 3 includes a flow sensor 3-1, a pressure sensor 3-2, a temperature sensor 3-3, and a stroke sensor 3-4. This allows it to obtain parameter information such as flow rate, pressure, temperature, and stroke during the operation of the hydraulic cylinder.

[0061] In some embodiments, the flow sensor 3-1 is used to detect the flow rate of hydraulic oil at the directional control valve. Specifically, the flow sensor 3-1 is installed at the front end of the directional control valve P port (i.e., oil inlet P), and the flow sensor 3-1 is used to measure the flow rate of hydraulic oil at the directional control valve P port.

[0062] In some embodiments, the flow sensor 3-1 is a turbine-type flow sensor.

[0063] In some embodiments, pressure sensor 3-2 is used to detect the pressure of hydraulic oil at the directional control valve, the oil pressure in the rodless chamber of the hydraulic cylinder, and the oil pressure in the rod chamber. Specifically, pressure sensors are installed at the P port of the directional control valve and the inlet and outlet ports of the hydraulic cylinder. Pressure sensor 3-2 is used to detect the pressure of hydraulic oil at the P port of the directional control valve (referred to as P port oil pressure), the oil pressure in the rodless chamber of the hydraulic cylinder, and the oil pressure in the rod chamber.

[0064] In some embodiments, temperature sensor 3-3 is used to detect the temperature of hydraulic oil in the temperature-controlled oil tank. The temperature sensor is located inside the temperature-controlled oil tank 1-1.

[0065] In some embodiments, the stroke sensor 3-4 is used to measure hydraulic cylinder stroke parameters, including the current extension of the piston rod of the hydraulic cylinder. The stroke sensor 3-4 is installed inside the bottom of the hydraulic cylinder. Specifically, the stroke sensor 3-4 is installed at the bottom of the rodless chamber of the hydraulic cylinder 6.

[0066] In some embodiments, the stroke sensor is a drawstring stroke sensor. In this case, using a drawstring stroke sensor to sense the length of piston rod extension and retraction can provide data support for achieving precise position control of the hydraulic cylinder.

[0067] In some embodiments, the signals (i.e., sensed electrical signals) collected by each sensor in the acquisition module 3 can be wirelessly communicated with the controller 12 (described later).

[0068] In this embodiment, the control module 4 is used to obtain a training dataset based on the vibration state under different working conditions, the characteristic parameters of the hydraulic oil, and the set action lead, and to use the training dataset to train a neural network model to obtain an action lead model.

[0069] In some embodiments, such as Figure 2 As shown, the control module 4 includes a controller 4-1 and a host computer 4-2.

[0070] In some embodiments, the controller 4-1 is used to receive the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder collected by the acquisition module and upload them to the host computer 4-2, and obtain the action advance model from the host computer 4-2.

[0071] Specifically, controller 4-1 may include a communication unit, a signal acquisition unit, and an AD conversion unit. The communication unit includes a wireless communication subunit and a wired communication subunit. Each sensor in acquisition module 3 sends the sensed electrical signals to the wireless communication subunit. The signal acquisition unit acquires the electrical signals received by the wireless communication subunit from the flow sensor, pressure sensor, stroke sensor, and temperature sensor. These electrical signals include characteristic parameters and hydraulic cylinder stroke parameters. The AD conversion unit converts the acquired electrical signals into physical signals and transmits these physical signals to the host computer 4-2 via the wired communication subunit. Controller 4-1 can also acquire vibration states under different operating conditions and transmit them to the host computer 4-2 via the wired communication subunit.

[0072] In some embodiments, the signal acquisition unit performs high-frequency acquisition of the electrical signals sent by the acquisition module 3.

[0073] In some embodiments, the host computer 4-2 is used to obtain the training dataset and the action lead model and to burn the action lead model to the controller 4-1.

[0074] Specifically, the host computer 4-2 obtains a training dataset based on the received vibration state and hydraulic oil characteristic parameters under different operating conditions, as well as the set action lead. It then uses the training dataset to train a neural network model to obtain an action lead model, which is then recorded onto the controller 4-1. The trained action lead model reflects the mapping relationship between characteristic parameters such as oil pressure, flow rate, temperature, and filtration accuracy, and vibration states such as vibration frequency and amplitude, and the action lead.

[0075] In addition, the training dataset is obtained based on the characteristic parameters and vibration states of the hydraulic cylinder under different operating conditions. Specifically, different characteristic parameters and vibration states are preset with corresponding action lead amounts. First, different characteristic parameters and vibration states are preset, and the hydraulic cylinder is made to work under the preset characteristic parameters and vibration states to obtain the actual characteristic parameters and vibration states. Then, the characteristic parameters and vibration states corresponding to the preset action lead amounts are replaced with the actual characteristic parameters and vibration states to obtain the training dataset.

[0076] In some embodiments, after obtaining the training dataset, MATLAB software can be used to process the data, and the processed training dataset can then be used for training.

[0077] In some embodiments, considering that the accuracy of the calculation results of the neural network algorithm (i.e., the neural network model) is directly related to the amount of data, in order to obtain rich data for analysis, an automatic reciprocating push-pull experimental program can be written, that is, two target positions, one large and one small, such as 150mm and 350mm, can be set, and the hydraulic cylinder can push and pull cyclically between these two positions to obtain rich experimental data.

[0078] In some embodiments, if a single-piston-rod hydraulic cylinder is used in the experiment, the piston rod exhibits differences in speed, error, pressure, and flow rate in both the pushing and retracting directions. During training, the mapping relationship between the two actions should be calculated separately, i.e., the action lead models corresponding to the two actions should be obtained. Therefore, by using the two action lead models to calibrate the hydraulic cylinder position obtained in a real-world environment, the accuracy of existing hydraulic cylinder position control can be further improved.

[0079] In this embodiment, the control module 4 is also used to input the characteristic parameters and vibration state of the hydraulic oil collected in real time into the action advance model after obtaining the action advance model to output the action advance, generate control commands based on the output action advance, target position and hydraulic cylinder stroke parameters, obtain the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than the preset error threshold, the action advance model is optimal; otherwise, the action advance model is optimized.

[0080] Specifically, the host computer 4-2 is also used to obtain the target position and send it to the controller 4-1. The controller 4-1 also includes a signal transmission unit and a data processing unit. The controller 4-1 receives the target position from the host computer 4-2, obtains real-time collected hydraulic cylinder stroke (i.e., hydraulic cylinder stroke parameters) and hydraulic oil pressure, flow rate, temperature, and other data from the wireless communication subunit. The data processing unit uses the action advance model as input, takes the real-time state of the hydraulic cylinder as input, and outputs the corresponding action advance for the current moment, such as oil pressure, flow rate, temperature, filtration accuracy, test bench vibration frequency (hereinafter referred to as vibration frequency), and amplitude. Based on the output action advance, target position, and hydraulic cylinder stroke parameters, a control command is generated. The control command is sent to the directional valve through the signal transmission unit to control the directional valve's action. The real-time state of the hydraulic cylinder movement includes characteristic parameters such as oil pressure, flow rate, temperature, and filtration accuracy, and vibration states such as test bench vibration frequency and amplitude. The data processing unit is also used to obtain the action error based on the hydraulic cylinder stroke parameters. If the action error is less than a preset error threshold, the action advance model is optimal; otherwise, the action advance model is optimized.

[0081] In some embodiments, the host computer 4-2 obtains the target location by means of inputting the target location through an input device such as a keyboard.

[0082] In some embodiments, the data processing unit may include a microcontroller (MCU) to process data in order to generate control commands and determine whether the action lead model is optimal.

[0083] In some embodiments, the controller 4-1 is further configured to upload the real-time status of the hydraulic cylinder movement to the host computer 4-2, and the host computer 4-2 is further configured to display the real-time status of the hydraulic cylinder movement.

[0084] In some embodiments, the control module 4 further includes a reversing button for manually testing whether the controller 4-1 is working properly.

[0085] In some embodiments, such as Figure 2 As shown, the experimental apparatus for precise position control of the hydraulic cylinder also includes a power supply module 5. The power supply module 5 provides a stable voltage to the data acquisition module 3 and the control module 4. Specifically, the power supply module 5 provides a stable voltage to each sensor in the data acquisition module 3 and the controller 4-1 in the control module 4. The power supply for the power supply module 5 is, for example, a 12V regulated power supply.

[0086] In some embodiments, the power module 5 can also provide a stable and reliable power supply to other modules.

[0087] In some embodiments, the controller 4-1, the host computer 4-2, and the power module 5 can be placed in a laboratory and use wired and wireless methods to power the reversing valve 2-1 and the sensor for signal transmission.

[0088] In some embodiments, the base of the experimental apparatus can be welded from steel plates and ribs. The maximum thrust exerted on the base by the hydraulic cylinder during operation is calculated to be, for example, 280 kN. Twelve YG1-M20 bolts can be used to fix it to the ground. The base has lugs welded to its front side, which are fixed to the bottom of the hydraulic cylinder by pins. Additionally, the experimental apparatus uses three pressure sensors, one stroke sensor, one flow sensor, and one temperature sensor. One pressure sensor is installed at the front end of the P port of the reversing valve to collect the pressure entering the experimental system; this pressure value is slightly less than the pump pressure. One pressure sensor is installed at the inlet / outlet interface of the rodless chamber to collect the pressure of the oil flowing into and out of the chamber (i.e., hydraulic oil). One pressure sensor is installed at the inlet / outlet interface of the rod chamber to collect the pressure of the oil flowing into and out of the chamber. The stroke sensor is a pull-string type sensor, installed in the bottom groove of the rodless chamber, with the pull string connected to the piston by a stud. The flow sensor is a turbine-type sensor, installed at the front end of the P port of the reversing valve to collect the flow rate entering the experimental system. The contact temperature sensor is placed in the temperature control oil tank to detect the temperature of the hydraulic oil, providing data support for achieving precise control of the hydraulic cylinder position.

[0089] Figure 3 This diagram illustrates a flowchart of an experimental method for obtaining a motion lead model according to an embodiment of this disclosure. In some embodiments, utilizing... Figure 2 The experimental method for obtaining the action lead model using the experimental setup shown is as follows:

[0090] S01. Programming: A visual user interface was designed using QT5 software for this experiment. To facilitate the acquisition of a large amount of sample data and leverage the advantages of computer repeatability, Keil μVision5 was used to write a program with functions including AD conversion, automatic target position assignment, reciprocating push-pull, and neural network calculation of action lead.

[0091] S02. Prepare the experimental setup: Based on the experimental requirements, prepare a base fixed to the ground, two 5t iron blocks as variable loads, and a regulated power supply providing 12V power to the sensors and controller. The sensors transmit the sensed electrical signals wirelessly to the controller's signal receiving module. After processing the data, the controller sends the optimal control command to the reversing valve to control the hydraulic cylinder's movement. The host computer and controller are connected via a serial port.

[0092] S03, Connect the experimental setup: According to Figure 2The experimental setup shown involves fixing the hydraulic cylinder to the base, with the piston rod pinned to the load. The hydraulic cylinder is placed above the vibratory machine. The inlet and outlet hydraulic lines are connected to the P and R ports of the directional valve, respectively. The working lines extend from ports A and B and connect to the interfaces of the rodless and rod-side chambers of the hydraulic cylinder. A tee adapter connects the pressure sensor and the working lines to the interfaces on the chambers. The installation positions of the stroke sensor and the pressure sensor at port P can be found in [reference needed]. Figure 2 .

[0093] S04. Powering on and starting the pump station: Turn on the power switch to supply power to the controller, sensors, and reversing valve using a regulated power supply. Turn on the controller and check if the indicator lights are on normally. Test if the reversing button can control the solenoid reversing valve. Turn on the pump station power and verify that the pump station is working properly.

[0094] S05. Setting parameters: Using the pump station adjusting handwheel, set the pump pressure to 31.5MPa and the flow rate to 100L / min. Secure a 5t load to the piston rod with a pin. Set the oil temperature to 40 degrees Celsius, the filtration accuracy to 20μm, the vibration frequency to 10Hz, and the amplitude to 30mm. Press the reversing button and test whether the entire system can operate. Input the target position into the host computer.

[0095] S06. Write program: Write the untrained neural network into the control program, and burn the program with data acquisition, processing and control functions into the controller.

[0096] S07. Acquire Real-Time Parameters: The host computer and controller are connected via a serial port, and the target position is transmitted to the controller. The sensor collects the current status of the hydraulic cylinder at a frequency of 30Hz and transmits it wirelessly to the controller's data processing module.

[0097] S08. Controlling the directional control valve: In the first experiment, the displacement amount (i.e., the advance amount) of the directional control valve is calculated according to the empirical formula. For example, if it is 5mm, the directional control valve will move 5mm ahead of the target position. In subsequent experiments, the mapping relationship between the obtained oil pressure, flow rate, oil temperature, filtration accuracy and displacement amount is processed by the advance amount model, and the displacement amount of the directional control valve is output. Based on this, the hydraulic cylinder is controlled to move.

[0098] S09. Calculation error: If the difference between the stroke parameters of the hydraulic cylinder in three consecutive cycles is less than 1 mm, the position at the end time is obtained based on the average value of the stroke parameters of the hydraulic cylinder in three consecutive cycles, and the error e between the position at the end time and the target position is calculated.

[0099] S10. Judgment Error and Industrial Allowable Error: Determine whether the judgment error e is less than the industrial allowable error. If yes, retain the average value of the action lead calculated this time. If no, the action lead model needs to be corrected (i.e. optimized) until the error e is less than the industrial allowable error, and the optimal action lead model is obtained.

[0100] In the experimental apparatus for precise position control of a hydraulic cylinder disclosed herein, the oil supply module provides hydraulic oil with different characteristic parameters to the hydraulic cylinder; the test module includes a directional valve, a vibration unit, and a load. The directional valve receives control commands from the control module to directionally control the hydraulic cylinder to push and pull the load; the vibration unit supports the hydraulic cylinder and provides vibration states under different working conditions; the load is connected to the hydraulic cylinder; the acquisition module collects the characteristic parameters of the hydraulic oil and transmits them to the control module; the control module obtains a training dataset based on the vibration states under different working conditions, the characteristic parameters of the hydraulic oil, and the set action lead, and uses the training dataset to train a neural network model to obtain an action lead model. In this case, by comprehensively considering the vibration states under different working conditions and the characteristic parameters of the hydraulic oil to obtain the action lead model, without changing the existing hydraulic cylinder position control system, the action lead model is used to calibrate the hydraulic cylinder position obtained by the hydraulic cylinder position control system in a real environment, thereby improving the control accuracy of the hydraulic cylinder position by the existing technology. The experimental apparatus disclosed herein fully considers the requirements of intelligent coal mining, which necessitates comprehensive sensing capabilities for face equipment, particularly for hydraulic cylinders. It requires sensing of inlet pressure, flow rate, oil temperature, filtration accuracy, and displacement position. Based on actual underground conditions, the experiment investigates the mapping relationship between various environmental parameters and the advance of directional valve action. This enables precise position control of the hydraulic cylinder during the experiment, thereby obtaining an optimal action advance model. This optimal model is then used to calibrate the hydraulic cylinder position obtained under actual conditions, further improving the accuracy of hydraulic cylinder position control in existing technologies and providing a new approach for precise hydraulic cylinder position control.

[0101] The following are embodiments of the method disclosed herein. For details not disclosed in the embodiments of the method disclosed herein, please refer to the embodiments of the apparatus disclosed herein. The embodiments of the method disclosed herein propose a method for precise position control of a hydraulic cylinder. This method for precise position control of a hydraulic cylinder uses an action lead model obtained from the experimental apparatus for precise position control of a hydraulic cylinder in the above-described apparatus embodiments for precise position control.

[0102] Figure 4 This diagram illustrates a flow chart of a method for precise position control of a hydraulic cylinder according to an embodiment of the present disclosure. The method for precise position control of a hydraulic cylinder includes:

[0103] S101, run the experimental device according to the preset parameters, obtain the vibration state of the hydraulic cylinder under different working conditions, the characteristic parameters of the hydraulic oil and the set action advance to generate a training dataset, and use the training dataset to train the neural network model to obtain the action advance model.

[0104] S102, under the actual working conditions of the hydraulic cylinder, the characteristic parameters of the hydraulic oil and the vibration state under the actual working conditions are collected in real time, and the position of the hydraulic cylinder is calculated. The characteristic parameters of the hydraulic oil collected in real time and the vibration state under the actual working conditions are input into the action advance model to output the action advance. The hydraulic cylinder is position controlled based on the calculated position of the hydraulic cylinder and the output action advance.

[0105] Optionally, after obtaining the action advance model in step S101, the method for precise position control of the hydraulic cylinder further includes optimizing the action advance model. The optimization process includes: running the experimental device under random parameters, collecting the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder in real time, inputting the real-time collected characteristic parameters and the obtained vibration state under the corresponding working condition into the action advance model to output the action advance, controlling the hydraulic cylinder to push and pull the load based on the output action advance, target position and hydraulic cylinder stroke parameters; obtaining the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than a preset error threshold, then the optimal action advance model is obtained.

[0106] Optionally, the motion error is obtained based on the hydraulic cylinder stroke parameters. If the motion error is less than a preset error threshold, the optimal motion advance model is obtained, including: obtaining at least three consecutive hydraulic cylinder stroke parameters and calculating the difference between adjacent hydraulic cylinder stroke parameters; if multiple differences are all less than a preset difference, the end position of the operation is obtained based on at least three consecutive hydraulic cylinder stroke parameters, and the motion error is obtained based on the end position of the operation and the target position; if the motion error is less than the preset error threshold, the optimal motion advance model is obtained.

[0107] In some embodiments, the end-of-run position can be obtained based on the average of at least three consecutive hydraulic cylinder stroke parameters.

[0108] In some embodiments, the hydraulic cylinder position calculated in S102 can be obtained using a hydraulic cylinder position control system.

[0109] In some embodiments, the process of operating the experimental apparatus under preset parameters and under random parameters specifically includes:

[0110] a. According to the experimental apparatus in the device embodiment, the hydraulic cylinder is placed on the vibratory machine, the bottom of the hydraulic cylinder is fixed on the base, the piston rod is fixed to the load with a pin, the inlet and return oil lines are connected to the P port and R port of the reversing valve, the working line is led out from the A port and B port and connected to the interface between the rodless chamber and the rod chamber of the hydraulic cylinder (i.e., the inlet and return oil ports), the pressure sensor is installed at the two inlet and return oil ports of the cylinder body using a three-way adapter, the P port pressure sensor is installed at the inlet of the P port of the reversing valve using a three-way adapter, the stroke sensor is installed at the bottom of the rodless chamber of the hydraulic cylinder, and the flow sensor is installed at the front end of the P port of the reversing valve.

[0111] b. Turn on the power to the pump station. Use the pressure regulating handwheel to set the working pump pressure and flow rate, the working temperature of the hydraulic oil, the working amplitude and frequency of the vibrator, and the filter with the set filtration accuracy. Fix several iron blocks as loads. Control the hydraulic cylinder 6 to push and pull back and forth between the target positions. The controller collects sensor values ​​at high speed and sends them to the host computer for storage, generating a CSV file including data such as position, P port pressure, A port pressure, B port pressure, flow rate, valve working status, host computer time, and running time. Reset different pump pressures, flow rates, temperatures, loads, and target positions to obtain multiple sets of experimental data.

[0112] c. The experiment was divided into several groups according to parameters such as oil pressure, flow rate, oil temperature, filtration accuracy, vibration amplitude, and frequency. MATLAB was used to process the raw data to obtain the start point, end point, average speed, and set action lead for each action. A neural network model was trained to obtain the mapping relationship between the set action lead and each parameter (i.e., the action lead model). This mapping relationship was then used for precise position control in subsequent actual working conditions.

[0113] d. Download the trained neural network model (i.e., the action lead model) to the controller to control the action of the directional valve. Use the state of the hydraulic cylinder sensed by the sensor as input, calculate the position to control the action of the directional valve according to the target position, realize the precise position control during the experiment, and obtain the error e. Based on the error e, determine whether to optimize the action lead model.

[0114] It should be noted that the explanation of the experimental device embodiment for precise position control of hydraulic cylinder described above also applies to the method for precise position control of hydraulic cylinder in this embodiment, and will not be repeated here.

[0115] The sequence numbers of the embodiments disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0116] In the hydraulic cylinder precise position control method disclosed herein, an experimental device is run according to preset parameters to obtain the vibration state of the hydraulic cylinder under different working conditions, the characteristic parameters of the hydraulic oil, and the set action advance amount to generate a training dataset. A neural network model is trained using this training dataset to obtain an action advance model. Under actual hydraulic cylinder operating conditions, the characteristic parameters of the hydraulic oil are collected in real time, the hydraulic cylinder position is calculated, and the vibration state under actual working conditions is obtained. The real-time collected hydraulic oil characteristic parameters and the vibration state under actual working conditions are input into the action advance model to output the action advance amount. Position control of the hydraulic cylinder is performed based on the calculated hydraulic cylinder position and the output action advance amount. In this case, the action advance model is obtained by comprehensively considering the vibration state and hydraulic oil characteristic parameters under different working conditions. Without changing the existing hydraulic cylinder position control system, this action advance model is used to calibrate the hydraulic cylinder position obtained by the hydraulic cylinder position control system in actual environments, improving the control accuracy of the hydraulic cylinder position in the prior art. The method disclosed herein fully considers the requirements of intelligent coal mining, which necessitates comprehensive sensing capabilities for face equipment, particularly for hydraulic cylinders. This requires sensing of inlet pressure, flow rate, oil temperature, filtration accuracy, and displacement position. Based on actual underground conditions, experiments are conducted to study the mapping relationship between various environmental parameters and the advance of directional valve action. This enables precise position control of the hydraulic cylinder during experiments, thereby obtaining an optimal action advance model. This optimal model is then used to calibrate the hydraulic cylinder position obtained under actual conditions, further improving the accuracy of hydraulic cylinder position control in existing technologies and providing a new approach for precise hydraulic cylinder position control.

[0117] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this disclosure does not impose any restrictions here.

[0118] It should be noted that, for the sake of simplicity, the foregoing method embodiments described in this disclosure are all presented as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this disclosure. Secondly, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and units involved are not necessarily essential to this disclosure. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0119] In this disclosure, the terms "upper," "lower," and other terms indicating orientation or positional relationship are used only for the convenience of describing this disclosure in a simplified manner, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be direct connections or indirect connections through an intermediate medium.

[0120] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An experimental device for precise position control of a hydraulic cylinder, characterized in that, It includes an oil supply and control module, a testing module, a data acquisition module, and a control module, among which, The oil supply and control module is used to provide hydraulic oil with different characteristic parameters to the hydraulic cylinder; The test module includes a reversing valve, a vibration unit, and a load. The reversing valve receives control commands from the control module to reverse the direction of the hydraulic cylinder and control the hydraulic cylinder to push and pull the load. The vibration unit supports the hydraulic cylinder and provides vibration states for the hydraulic cylinder under different working conditions. The load is connected to the hydraulic cylinder. The acquisition module is used to acquire the characteristic parameters of the hydraulic oil and transmit them to the control module; The control module is used to obtain a training dataset based on the vibration state under different working conditions, the characteristic parameters of hydraulic oil and the set action advance, and to use the training dataset to train a neural network model to obtain an action advance model. The acquisition module is also used to acquire hydraulic cylinder stroke parameters. The control module is also used to, after obtaining the action advance model, input the characteristic parameters and vibration state of the hydraulic oil acquired in real time into the action advance model to output the action advance, generate the control command based on the output action advance, target position and hydraulic cylinder stroke parameters, obtain the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than a preset error threshold, the action advance model is optimal; otherwise, the action advance model is optimized.

2. The experimental apparatus for precise position control of a hydraulic cylinder as described in claim 1, characterized in that: The hydraulic oil supply and control module includes a variable pump, a temperature-controlled oil tank, and a filter. The temperature-controlled oil tank is used to provide hydraulic oil at different temperatures. The variable pump is used to adjust the pressure and flow rate of the hydraulic oil. The filter is used to adjust the filtration accuracy of the hydraulic oil. The characteristic parameters include the temperature, flow rate, and pressure of the hydraulic oil.

3. The experimental apparatus for precise position control of a hydraulic cylinder as described in claim 1, characterized in that: The vibration unit includes a base and a vibrator. The base is used to fix the hydraulic cylinder. The hydraulic cylinder is fixed to the base by studs. The piston rod of the hydraulic cylinder is fixed to the load. The vibrator is used to provide the hydraulic cylinder with vibration states under different working conditions. The vibration states include vibration amplitude, vibration frequency and vibration acceleration.

4. The experimental apparatus for precise position control of a hydraulic cylinder as described in claim 2, characterized in that: The acquisition module includes a flow sensor, a pressure sensor, a temperature sensor, and a stroke sensor. The flow sensor is used to detect the flow rate of hydraulic oil at the directional valve. The pressure sensor is used to detect the pressure of hydraulic oil at the directional valve, the oil pressure in the rodless chamber of the hydraulic cylinder, and the oil pressure in the rod chamber. The temperature sensor is used to detect the temperature of the hydraulic oil in the temperature-controlled oil tank. The stroke sensor is used to measure the stroke parameters of the hydraulic cylinder, including the current extension amount of the piston rod of the hydraulic cylinder.

5. The experimental apparatus for precise position control of a hydraulic cylinder as described in claim 4, characterized in that: The flow sensor is a turbine flow sensor, the stroke sensor is a pull-rope stroke sensor, and the reversing valve is an electromagnetic reversing valve.

6. The experimental apparatus for precise position control of a hydraulic cylinder as described in claim 1, characterized in that: The control module includes a controller and a host computer. The controller is used to receive the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder collected by the acquisition module and upload them to the host computer, and obtain the motion advance model from the host computer. The host computer is used to obtain the target position, training dataset and motion advance model, and send the target position to the controller and burn the motion advance model to the controller.

7. A method for precise position control of a hydraulic cylinder, characterized in that, The method for precise position control of the hydraulic cylinder utilizes an action lead model obtained from the experimental apparatus for precise position control of the hydraulic cylinder as described in any one of claims 1-5 to perform precise position control, and includes: The experimental device is run according to preset parameters to obtain the vibration state of the hydraulic cylinder under different working conditions, the characteristic parameters of the hydraulic oil, and the set action advance to generate a training dataset. The neural network model is trained using the training dataset to obtain the action advance model. In the actual working condition of the hydraulic cylinder, the characteristic parameters of the hydraulic oil and the vibration state under the actual working condition are collected in real time, and the position of the hydraulic cylinder is calculated. The characteristic parameters of the hydraulic oil collected in real time and the vibration state under the actual working condition are input into the action advance model to output the action advance. The hydraulic cylinder is position controlled based on the calculated position of the hydraulic cylinder and the output action advance.

8. The method for precise position control of a hydraulic cylinder as described in claim 7, characterized in that, After obtaining the action advance model, the process further includes optimizing the action advance model. The optimization process includes: running the experimental device under random parameters, collecting the characteristic parameters of the hydraulic oil and the stroke parameters of the hydraulic cylinder in real time, inputting the real-time collected characteristic parameters and the obtained vibration state under the corresponding working condition into the action advance model to output the action advance, controlling the hydraulic cylinder to push and pull the load based on the output action advance, target position and hydraulic cylinder stroke parameters; obtaining the action error based on the hydraulic cylinder stroke parameters, and if the action error is less than a preset error threshold, then the optimal action advance model is obtained.

9. The method for precise position control of a hydraulic cylinder as described in claim 8, characterized in that, The process of obtaining the motion error based on the hydraulic cylinder stroke parameters, and obtaining the optimal motion lead model if the motion error is less than a preset error threshold, includes: Obtain at least three consecutive hydraulic cylinder stroke parameters and calculate the difference between adjacent hydraulic cylinder stroke parameters; If multiple differences are all less than a preset difference, the position of the end of operation is obtained based on the at least three consecutive hydraulic cylinder stroke parameters. The motion error is obtained based on the position at the end of the operation and the target position; If the action error is less than a preset error threshold, then the optimal action lead model is obtained.

Images