Self-moving tail leveling control method and device, computer equipment and medium

Abstract

The invention provides a self-moving tail leveling control method and device, computer equipment and a medium, and belongs to the field of equipment control, the method comprises the following steps: obtaining a space pose of a self-moving tail leveling rack through an inertial gyroscope, and further calculating expected displacement values of leveling hydraulic cylinders at four corners of the self-moving tail based on a three-dimensional space Euler angle method; on the basis of the current working stage of the self-moving tail, the opening degree of a servo valve connected with a leveling hydraulic cylinder is controlled, and the method comprises the steps that in the leveling stage, the geometric center point of the self-moving tail serves as the standard, and a leveling hydraulic cylinder supporting point at the current middle position point serves as a fixed reference point; according to the expected displacement value, displacements of pistons of the other three leveling hydraulic cylinders are asynchronously adjusted; according to the technology, the leveling efficiency is remarkably improved, the single-time operation time is obviously shortened compared with that of a traditional method, meanwhile, the oil leakage risk is eradicated through pressure threshold control, and the service life of hydraulic elements is greatly prolonged.

Description

Technical Field

[0001] This invention belongs to the field of equipment control, and specifically relates to a self-moving tail leveling control method, device, computer equipment and medium. Background Technology

[0002] Existing self-propelled tail jacks are mostly stepping-type, characterized by their compact structure and high hydraulic pushing force. They mechanize coal cutting, loading, support, crushing, and transportation in fully mechanized mining faces, meeting the requirements of high-yield and high-efficiency working faces. However, after movement, stepping-type self-propelled tail jacks often tilt due to changes in coal seam geological conditions, dynamic load fluctuations, and hydraulic system interference. They cannot automatically adjust, and the adjustment process is cumbersome and time-consuming, potentially leading to production interruptions and increased costs. While stepping-type self-propelled tail jacks have undergone years of practical improvements, their operation still relies on manual labor. Multiple control levers are densely distributed on the system's control valves, each controlling the oil inlet direction of one or a pair of hydraulic cylinders. This manual control method is crude, and the real-time operating parameters of the hydraulic cylinders cannot be obtained during control. This can lead to hydraulic cylinder pressure exceeding the allowable range, causing oil leakage, sudden retraction of hydraulic rods, and other unstable conditions. This not only affects leveling accuracy but also damages hydraulic components, increasing equipment maintenance costs. Moreover, the underground environment is harsh and complex, the self-propelled tail section is heavy, and the varying thickness of the coal seam and the changing working conditions make the leveling process of the self-propelled tail section face many uncertainties. Traditional manual adjustment methods are no longer suitable for the efficient, precise, and safe production requirements of modern fully mechanized mining faces. Therefore, it is particularly urgent to develop a self-propelled tail section leveling method with autonomous leveling function. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a self-moving tail leveling control method, apparatus, computer equipment, and medium.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A self-moving tail leveling control method, the method comprising: The spatial pose of the self-moving tail leveling frame is obtained, and then the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail are calculated based on the three-dimensional space Euler angle method. Based on the current working stage of the self-moving tail section, the opening degree of the servo valve connected to the leveling hydraulic cylinder is controlled, including: During the cylinder raising phase, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. During the leveling phase, the geometric center point of the self-moving tail is used as a reference, and the support point of the leveling hydraulic cylinder at the current midpoint is selected as a fixed reference point. According to the desired displacement value, the displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted. During the retraction phase, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil provided by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

[0005] Optionally, the spatial pose includes pitch angle, roll angle, and yaw angle, and the calculation of the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional Euler angle method includes: Define the coordinates of the four corner support points when in a horizontal position; Based on pitch angle θ, roll angle φ, and yaw angle Construct the rotation matrix: ; The coordinates of the support point in the horizontal state are mapped to the current tilted coordinate system using a rotation matrix to obtain the theoretical Z-axis coordinates of the support point in the current tilted state. The desired displacement of each hydraulic cylinder is determined based on the measured displacement of the fixed reference point.

[0006] Optionally, during the leveling stage, a variable universe fuzzy PID control method based on a hybrid scaling factor is used to control the displacement of the pistons of each leveling hydraulic cylinder in asynchronous adjustment, including: Real-time calculation of the displacement error and error rate of the hydraulic cylinder piston between the actual displacement and the expected displacement; By using a hybrid scaling factor, the displacement error and the rate of change of error are scaled separately to obtain the adjusted input variables; The scaled input variables are input to the fuzzy controller, which infers based on the preset fuzzy rule table and outputs the PID parameter adjustment amount. The hybrid scaling factor is used as the output scaling factor to synchronously scale the adjustment amount of the PID parameters output by the fuzzy inference, and the final PID parameters are determined by the scaled PID parameter adjustment amount. The final PID parameters are used to generate a control signal to drive the servo valve and control the leveling hydraulic cylinder.

[0007] Optionally, the formula for calculating the hybrid scaling factor includes: Error scaling factor: ; Error rate of change scaling factor: ; in, For displacement error; The rate of change of error; This is a mixing coefficient, adjusted based on the relationship between the displacement error and a preset error threshold. , This is the adjustment coefficient for the functional part; For the first The membership degree of a fuzzy rule; For the first Output the scaling factor corresponding to each fuzzy rule.

[0008] Optionally, back pressure control is performed during the cylinder lifting stage, including: Detect the pressure P2 in the rod chamber and the pressure P1 in the rodless chamber; Adjust the opening of the rod chamber valve to make P2 ≤ 0.4P1 - 0.2MPa.

[0009] Optionally, speed control is performed during the retraction phase, including: Set velocity curve v ref =v0e −t / τ ; Where v0 is the initial retraction velocity, and τ is the velocity decay time constant; The return oil flow rate Q=A is adjusted by the rodless chamber regulating valve. rod v ref ; Among them, A rod This represents the cross-sectional area of ​​the piston.

[0010] Optionally, the following actions are performed on the retracted leveling hydraulic cylinder during the leveling phase: The fully open rod chamber servo valve ensures that the rod chamber pressure is ≤0.2MPa; The opening degree of the rodless chamber servo valve is controlled to regulate the return oil flow. The oil return portion of the rodless chamber is injected into the rod chamber through the regeneration channel.

[0011] A self-moving tail leveling control device, the device comprising: The determination module is used to obtain the spatial pose of the self-moving tail leveling frame through an inertial gyroscope, and then calculate the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method. The leveling module, used to control the opening of the servo valve connected to the leveling hydraulic cylinder based on the current working stage of the self-propelled tail section, includes: During the cylinder raising phase, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. During the leveling phase, the support point of the leveling hydraulic cylinder at the current midpoint is selected as a fixed reference point, using the geometric center point of the self-moving tail as a reference. The displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted according to the desired displacement value. During the retraction phase, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil supplied by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

[0012] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned self-moving tail leveling control method.

[0013] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned self-moving tail leveling control method.

[0014] The self-moving tail leveling control method provided by this invention has the following beneficial effects: This invention captures the three-dimensional attitude of the frame in real time and dynamically calculates the target displacement of the hydraulic cylinder using Euler angle algorithms, achieving millimeter-level leveling accuracy. The system employs a phased closed-loop control strategy: during the cylinder raising stage, the oil intake in the rodless chamber is precisely adjusted via a servo valve, while simultaneously limiting the back pressure in the rod chamber to eliminate hydraulic shock; during the leveling stage, the piston displacement of the three cylinders is asynchronously adjusted based on the geometric center, effectively addressing sudden changes in coal seam thickness; and during the retraction stage, the piston is smoothly retracted through dual-valve linkage. This technology significantly improves leveling efficiency, with a marked reduction in single-operation time compared to traditional methods. Simultaneously, pressure threshold control eliminates the risk of oil leakage, significantly extending the service life of hydraulic components. Its core value lies in transforming the uncertainties of the harsh underground environment into controllable parameters, providing a reusable technological paradigm for the intelligentization of coal mine equipment, possessing both engineering practicality and promising prospects for industry promotion. Attached Figure Description

[0015] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a self-moving tail leveling control method provided by the present invention according to an exemplary embodiment.

[0017] Figure 2 This is a schematic diagram of the overall structure of a self-moving tail section according to an exemplary embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of a self-moving tail leveling system provided by the present invention according to an exemplary embodiment.

[0019] Figure 4 This is a schematic diagram of a self-moving tail leveling system provided by the present invention according to an exemplary embodiment.

[0020] Figure 5 This is a schematic diagram of the operation of a leveling hydraulic cylinder according to an exemplary embodiment of the present invention; wherein, (a) is a schematic diagram of the cylinder raising stage, (b) is a schematic diagram of the leveling stage, and (c) is a schematic diagram of the retraction stage.

[0021] Figure 6 This is a schematic diagram of pressure control of an oil chamber according to an exemplary embodiment of the present invention; wherein, (a) is a pressure relief scenario of excessive pressure in the rodless chamber, and (b) is a pressure relief scenario of excessive pressure in the rod chamber.

[0022] Figure 7 This is a schematic diagram of a dynamic domain adjustment principle provided by the present invention according to an exemplary embodiment.

[0023] Figure 8 This is a block diagram of a self-moving tail leveling control device provided by the present invention according to an exemplary embodiment. Detailed Implementation

[0024] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0025] This invention designs a self-propelled tailplane leveling control system based on independent load ports. The system consists of four independent sets of dual-valve-controlled single-cylinder loops, enabling independent movement of each cylinder. Then, based on the system characteristics under different working conditions of the self-propelled tailplane, a bidirectional cooperative control strategy for each centering point is proposed. Finally, simulation software is used to simulate the dynamic performance and energy characteristics of the designed leveling system and control method during the docking and forming stages, verifying the effectiveness of the control method and strategy. This invention provides technical support for further improving the intelligence of self-propelled tailplane leveling.

[0026] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] First, this invention provides a self-moving tail leveling control method, specifically as follows: Figure 1As shown, it includes the following steps: S101. Obtain the spatial pose of the self-moving tail leveling frame, and then calculate the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method.

[0028] The spatial pose includes pitch angle, roll angle, and yaw angle. To determine the desired displacement, it is first necessary to define the coordinates of the support points at the four corners in the horizontal state; then, based on the pitch angle θ, roll angle φ, and yaw angle... Construct the rotation matrix: .

[0029] The coordinates of the support point in the horizontal state are mapped to the current tilted coordinate system through a rotation matrix to obtain the theoretical Z-axis coordinates of the support point in the current tilted state; the expected displacement of each hydraulic cylinder is determined based on the measured displacement of this fixed reference point.

[0030] In one embodiment, the system principle of the present invention is first analyzed. First, the structure of the self-moving tail section is determined. The overall structure of the self-moving tail section of the belt conveyor (taking a stepping type as an example) is as follows: Figure 2 As shown, it includes a bracket, a sliding frame, a leveling hydraulic cylinder, a front support, a pushing cylinder, a frame, a machine head, and a rear support. The self-moving tail leveling execution system is composed of the four leveling hydraulic cylinders in the front and rear supports and the frame. The self-moving tail leveling system designed in this invention, based on a load port independent control strategy, is as follows... Figure 3 As shown, the system consists of hydraulic cylinders, a hydraulic pump, a servo motor, a hydraulic accumulator, a relief valve, a servo valve, a leveling hydraulic cylinder, a displacement sensor, and a pressure sensor. To ensure control accuracy and for energy conservation, each hydraulic cylinder is independently controlled for pressure and flow via two servo valves. By configuring independent pressure and flow circuits for each leveling cylinder, decoupled control of the cylinder's actions is achieved, thereby improving the system's response speed and leveling accuracy.

[0031] The system employs a four-cylinder support structure, with four leveling hydraulic cylinders positioned at the four corners of the self-propelled conveyor tail frame system. These cylinders are numbered 1, 2, 3, and 4. During leveling, each hydraulic cylinder can independently adjust its piston displacement according to controller commands to adapt to changes in the tunnel floor, ensuring the tail of the belt conveyor remains horizontal. A MEMS inertial gyroscope is used to acquire the pose of the entire leveling frame, calculating the target displacement of the four cylinders. Each hydraulic cylinder has a built-in magnetic ring displacement sensor that generates a displacement signal. Pressure sensors are installed at the rodless and rod-side ports of each leveling cylinder to obtain the pressure in both oil chambers of each cylinder.

[0032] Then, the mathematical model of the leveling hydraulic cylinder was designed in this invention. The position control system of the leveling hydraulic cylinder for the self-moving tail section mainly consists of a displacement sensor, an electro-hydraulic servo valve, and a valve-controlled hydraulic cylinder, etc. The system schematic diagram is shown below. Figure 4 As shown, a generalized functional relationship between the displacement output of a single leveling hydraulic cylinder and the signal input of the control point is established based on the system characteristics, providing a theoretical basis for selecting a suitable control method.

[0033] Assumption The force balance equations for each leveling cylinder are as follows: ; In the formula, and These refer to the pressure in the rodless chamber of the hydraulic cylinder and the pressure in the rod chamber of the hydraulic cylinder, respectively. and These refer to the effective working areas of the rodless chamber and the rod chamber of the hydraulic cylinder, respectively. The mass of the piston distributed across the piston of a single hydraulic cylinder; This represents the displacement of the hydraulic cylinder piston. The viscous damping coefficient of the piston and load; The elastic stiffness of the load; The load force exerted on the piston of a single leveling cylinder is downward.

[0034] The flow continuity equation for a hydraulic cylinder is: ; In the formula, and These represent the controllable volumes of the rodless chamber and the rod chamber of the hydraulic cylinder, respectively. The effective elastic modulus; and These represent the flow rates in the rodless chamber and the rod chamber, respectively. The piston rod seal is leaking. The cylinder seal is leaking. This is the internal leakage coefficient of the hydraulic cylinder.

[0035] According to the spool valve flow equation, the servo valve flow... and valve core displacement The pressure drop relationship across the servo valve throttling orifice is as follows: ; In the formula, ,in For flow coefficient, The gradient of the oil chamber area of ​​the servo valve; ,in For the displacement of the servo valve spool, For servo valve control signals; For oil source pressure; For symbolic functions, it is defined as: ; The hydraulic cylinder return port must allow the load displacement to follow a given displacement. Define the state variable as:

[0036] ; The state equation is: ; in, ; .

[0037] In another embodiment, during the leveling process, it is first necessary to calculate the spatial displacement difference of each cylinder relative to the hydraulic cylinder corresponding to the set point, so a spatial coordinate system transformation must be performed first. This can be further understood as the spatial coordinates of the target angle changing from the initial coordinate system to the target coordinate system by sequentially rotating around three coordinate axes. The desired displacement of the leveling hydraulic cylinders in the self-moving tail leveling system is then calculated based on this spatial attitude change theory.

[0038] Assuming the geometric center point of the self-moving tail section frame is G, establish a spatial rectangular coordinate system for the initial position at the highest point A of the output displacement of the hydraulic cylinder supporting the column. This is called the initial coordinate system, and the spatial rectangular coordinate system that has been adjusted to a horizontal position after spatial orientation. This is called the horizontal coordinate system. The width and length of the entire leveling section are respectively... and The four leveling hydraulic cylinders are located at points 1, 2, 3, and 4 at the lower end of the machine body, respectively, in the initial coordinate system. The coordinates in the equation can be represented as follows: , , and After spatial attitude transformation, it is in the horizontal coordinate system The coordinates in the equation can be represented as follows: , , and in and These are the length and width of the top beam, respectively. The initial coordinate matrices of the four corners can then be obtained. With horizontal coordinate matrix They are respectively:

[0039] .

[0040] Initial coordinate system Around The angle of rotation of the shaft is the roll angle. At this point, the initial coordinate system becomes ; around The angle of rotation of the axis is the pitch angle. At this point, the initial coordinates become ; around The angle of rotation of the axis is the yaw angle. Construct rotation matrix : .

[0041] Multiplying the above matrices together yields the complete rotation matrix from the initial coordinate system to the horizontal coordinate system: ; .

[0042] Since the research focus of this invention is on how the machine body, supported by four leveling hydraulic cylinders at the tail end of the self-moving machine, maintains a horizontal position in uneven roadways, [the following is unclear and likely incomplete: "around"] The angle of axis rotation is not the focus of the study, so it is removed. This is done to simplify computational complexity. The simplified rotation matrix is ​​as follows:

[0043] .

[0044] Therefore, the rotation matrix from the initial coordinate system to the horizontal coordinate system for: .

[0045] Points in the initial coordinate system Transform to horizontal coordinate system : .

[0046] Since the rotation matrices are all orthogonal matrices, we can derive the result from the horizontal coordinate system. To the initial coordinate system The spatial transformation relationship is as follows: .

[0047] Substituting into the coordinate matrix, we can obtain the result from the horizontal coordinate system. To the initial coordinate system The inverse solution expression is: .

[0048] by Using the reference point, the desired output displacement of the four leveling hydraulic cylinders can be obtained as follows: ; In the formula, Therefore The displacement of the point is used as a reference value and is measured by the displacement sensor built into the hydraulic cylinder.

[0049] Based on the coordinate rotation principle of the Euler angle method, the propagation relationship of Euler angles over time can be expressed using the angular rate measured by a MEMS gyroscope: ; In the formula , , They are respectively , , angular rate of rotation of the shaft Simplifying the above equation, we can derive the differential equation for the Euler angle algorithm as follows: .

[0050] According to the Euler angle algorithm, the corresponding pose angles can be obtained by solving the relevant differential equations. Substituting these values ​​into the above equation yields the desired displacement of each leveling hydraulic cylinder.

[0051] S102, Control the opening degree of the servo valve of the leveling hydraulic cylinder based on the current working stage of the self-moving tail.

[0052] This process consists of three stages. In the lifting stage, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. In the leveling stage, the highest leveling hydraulic cylinder support point is selected as a fixed reference point, using the geometric center point of the self-moving tail as a reference. The displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted according to the desired displacement value. In the retraction stage, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil supplied by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

[0053] In one embodiment, to ensure the accuracy of the hydraulic cylinder position and the speed of system response, the present invention divides the leveling hydraulic cylinder action into three stages: cylinder lifting stage, such as Figure 5 As shown in diagram a, in the initial state, the hydraulic rod extension displacement is zero, and the hydraulic cylinder needs to extend to the initial set position. The oil source provided by the hydraulic pump is input to the oil inlet chamber of the leveling cylinder through the rodless chamber control valve. The rodless chamber control valve determines its valve opening according to the control signal, and the rod chamber control valve determines its opening according to the required flow rate, to ensure that the hydraulic rod extension speed is sufficient and the back pressure is kept low. This allows the pressure in the rodless chamber to overcome the load force, causing the piston to move upward and reach the set initial value.

[0054] Leveling phase, such as Figure 5As shown in Figure b, after the hydraulic rod extends to the set displacement, each hydraulic cylinder enters the leveling stage. During this stage, the hydraulic cylinders do not require large stroke displacements. To reduce system energy consumption and improve dynamic response, an overload energy regeneration retraction (LSRR) control strategy is adopted. Since the load and speed directions of the leveling cylinders are the same, the rod chamber of the leveling cylinder is in a near-vacuum state. The control valves connecting the rod chamber and the rodless chamber are also fully open, maximizing the flow rate into the rod chamber and minimizing the pressure in the rod chamber. The oil in the rodless chamber of the leveling cylinder returns to the oil tank through the return oil chamber control valve, and then the pressure difference forces the oil back into the rod chamber. The flow rate of the leveling cylinder is controlled by controlling the valve core of the rodless chamber control valve, so that the piston follows the given displacement.

[0055] During the retraction phase, to ensure the speed and stability of retraction, an overload fuel injection retraction control strategy (LSR) is adopted, such as... Figure 5 As shown in Figure c, the hydraulic pump supplies oil to the rod chamber of the leveling cylinder through the rod chamber control valve. The rod chamber control valve is set to the fully open state to maximize the flow rate into the rod chamber and minimize the pressure in the rod chamber. The oil in the rodless chamber of the leveling cylinder returns to the oil tank through the rodless chamber control valve. The rodless chamber control valve controls the valve opening by changing the valve core displacement to ensure stable retraction of the hydraulic rod.

[0056] Furthermore, to address unsafe conditions such as oil leakage and sudden retraction of the hydraulic rod during the entire hydraulic cylinder operation, this invention incorporates pressure control for each oil chamber alongside position control. This addresses severe pressure fluctuations caused by oil leakage, sudden load changes, or pressure shocks. When the pressure within an oil chamber reaches a threshold limit, the valve on that chamber side is fully opened to rapidly reduce the pressure to within a safe threshold. Figure 6 As shown in a. From Figure 6 As can be seen from diagram a, when the pressure in the rodless chamber exceeds or reaches the safety threshold, the valve on that side fully opens to discharge hydraulic oil back into the cylinder, thereby rapidly reducing the pressure in that chamber. Figure 6 The same applies to b.

[0057] For example, back pressure control is performed during the cylinder raising phase by detecting the rod chamber pressure P2 and the rodless chamber pressure P1; the rod chamber valve opening is adjusted so that P2 ≤ 0.4P1 - 0.2 MPa. Speed ​​control is performed during the retraction phase by setting the speed curve v. ref =v0e −t / τ Where v0 is the initial retraction velocity, and τ is the velocity decay time constant; the return oil flow rate Q=A is adjusted by the rodless chamber regulating valve. rod v ref Among them, A rodHere is the piston cross-sectional area. During the leveling phase, the retraction cylinder is operated on, opening the regeneration oil circuit between the rod chamber and the rodless chamber; when P1-P2>0.5MPa, 30%±5% of the return oil is injected into the rod chamber; or, the rod chamber servo valve is fully opened to make the rod chamber pressure ≤0.2MPa; the opening degree of the rodless chamber servo valve is controlled to adjust the return oil flow; and the return oil portion from the rodless chamber is injected into the rod chamber through the regeneration channel.

[0058] In practical applications of self-propelled tail jacks, traditional synchronous control methods are typically suitable for ideal conditions with perfectly flat ground. However, due to the complex geological environment underground in coal mines, the tunnel floor often exhibits unevenness, preventing the four supporting hydraulic cylinders of the self-propelled tail jack from being aligned on the same reference plane. This makes leveling impossible with traditional synchronous control. Assuming the self-propelled tail jack's body is a rigid structure, if one corner is higher than the others, the base will be suspended if unloaded. If coal flows through the self-propelled tail jack, it will tilt, causing the belt to tilt relative to the body, resulting in belt wear. To address this problem, an asynchronous control method is introduced, employing a "setpoint stationary" leveling method. This means that when the body tilts, one of the four corners is stationary, while the remaining hydraulic cylinders continue to move upwards or downwards to align with it, achieving leveling.

[0059] In order to improve control efficiency during the leveling stage, this invention employs a variable universe fuzzy PID control method based on a hybrid scaling factor to control the displacement of the pistons of each leveling hydraulic cylinder that is asynchronously adjusted.

[0060] First, the displacement error and error rate of change are calculated in real time; then, the proportional coefficient adjustment, integral coefficient adjustment, and derivative coefficient adjustment are output through a fuzzy rule table; finally, a control signal is generated. The displacement error and rate of change of the hydraulic cylinder piston between the actual and desired displacement are calculated in real time. A hybrid scaling factor is used to scale the displacement error and rate of change of the error, respectively, to obtain the adjusted input variables. The scaled input variables are then input to a fuzzy controller, which infers the PID parameter adjustment amount based on a preset fuzzy rule table. This hybrid scaling factor is used as the output proportional factor to synchronously scale the PID parameter adjustment amount output by the fuzzy inference, and the scaled PID parameter adjustment amount is used to determine the final PID parameters. Finally, the final PID parameters are used to generate a control signal to drive the servo valve to control the leveling hydraulic cylinder.

[0061] In one embodiment, the present invention finds that existing fuzzy control relies on pre-defined fuzzy control rules based on errors. and error change rate Adjust the scaling factor according to the scope of the domain. Integral coefficient and differential coefficients Dynamically adjusting PID parameters alone is insufficient to simultaneously meet the system's requirements for rapid response under large error conditions and high-precision control under small error conditions. To balance system speed and stability, the domain of discourse is dynamically adjusted according to system requirements, shrinking as the system control deviation decreases. A variable domain of discourse fuzzy PID control structure is shown below. Figure 7 As shown in the attached figure, this figure also includes the principle of dynamic adjustment of the universe of discourse proposed in this invention. Specifically, it is stated as follows: assuming the input variable is error... With error change rate The corresponding initial universes are respectively and The output variable is the adjustment amount of the proportional coefficient. Integral coefficient adjustment and differential coefficient adjustment amount .

[0062] The initial domain is By introducing a universe scaling factor, the universe can be expressed as:

[0063] ; ; ; In the formula: , and All of these are domain scaling factors.

[0064] Under fuzzy PID control, the system output gradually converges to the setpoint, and the error is near the midpoint of the input universe of discourse. Obviously, if the value is too large, the system will oscillate within a certain range, leading to a decrease in the system's control accuracy. At this point, by utilizing the concept of variable universe of discourse, without changing the number of fuzzy control rules or the type of membership function, the universe of discourse can be compressed or expanded by changing the scaling factor to achieve dynamic adjustment.

[0065] During system operation, an error signal e(t) is generated by comparing the given displacement signal with the actual displacement feedback signal. This error signal e(t) is first fed into a hybrid scaling factor generator. This generator is the intelligent core of the system; based on the dynamic changes of the error e(t) and according to a specific hybrid algorithm (as defined in claim 4), it calculates and outputs the hybrid scaling factor α in real time.

[0066] Next, the scaling factor α is used simultaneously in two parallel adjustment processes: Input universe adjustment: The original error e(t) is multiplied by the scaling factor α to obtain the compressed or expanded error signal e' = α · e(t), which is used as the preprocessed input signal.

[0067] Output scaling adjustment: The scaling factor α is directly defined as the output scaling factor. β u This is intended for subsequent output gain adjustment.

[0068] The preprocessed signal e' then enters the fuzzy controller. Here, the controller infers from the input signal according to a preset fuzzy rule set and calculates the adjustment amounts of the three parameters of the PID controller online.

[0069] Next, at the output end, the output scaling factor comes into play. It synchronously scales the parameter adjustment amount output by the fuzzy controller to generate the final parameter correction amount.

[0070] These corrections are fed into the PID controller and combined with the initial parameters K_p0, K_i0, and K_d0 to form real-time control parameters. The PID controller uses these parameters to process the signal and generate precise control commands u(t).

[0071] This command ultimately drives the hydraulic system and its working mechanism to perform the corresponding leveling action. The actual displacement of the working mechanism is detected by sensors and returned to the system input as a displacement feedback signal. This signal is then compared with the given displacement, thus forming a precise and adaptive closed-loop control system that ensures high performance in the leveling process.

[0072] Based on experience, the fuzzy control rules in the fuzzy PID controller are determined as shown in Tables 1-3.

[0073] Table 1 Fuzzy control rules Table 2 Fuzzy control rules Table 3 Fuzzy control rules This invention proposes a hybrid scaling factor method, whose output scaling factor is achieved through dynamic weight optimization. The core of this method lies in intelligently integrating the advantages of functional and fuzzy inference strategies based on the error magnitude: when the error is large, the speed of the functional approach is emphasized to accelerate the response; when the error is small, the accuracy of the fuzzy approach is emphasized to suppress overshoot and improve steady-state accuracy. This method dynamically optimizes the weights of the two strategies in the final decision, enabling the system to respond quickly like functional control when facing large errors, and to be precise, smooth, and without overshoot like fuzzy inference control when facing small errors. Ultimately, this significantly shortens the settling time and suppresses steady-state fluctuations. The expression for this hybrid scaling factor is:

[0074] ; ; In the formula: For error; This is a mixing coefficient, adjusted based on the relationship between the displacement error and a preset error threshold. For example, when the absolute value of the displacement error is greater than the preset error threshold, it can be set... It emphasizes a fast, function-based response. When the absolute value of the displacement error is less than or equal to a preset error threshold, it can be set... It emphasizes fuzzy reasoning-based precise control; , The adjustment coefficient for the functional part is in this invention. It can take the value 0.6. It can take the value 0.8; For the first The membership degree of a fuzzy rule; For the first Output the scaling factor corresponding to each fuzzy rule.

[0075] ; In the formula: To output the scaling factor; This is the scaling factor.

[0076] Using the above method, this invention achieves millimeter-level leveling accuracy by capturing the three-dimensional posture of the frame in real time and dynamically calculating the target displacement of the hydraulic cylinder using the Euler angle algorithm. The system employs a phased closed-loop control strategy: during the cylinder raising stage, the oil intake in the rodless chamber is precisely adjusted via a servo valve, while simultaneously limiting the back pressure in the rod chamber to eliminate hydraulic shock; during the leveling stage, the displacement of the three-cylinder piston is asynchronously adjusted based on the geometric center to effectively address sudden changes in coal seam thickness; and during the retraction stage, the piston is smoothly retracted through dual-valve linkage. This technology significantly improves leveling efficiency, with a marked reduction in single-operation time compared to traditional methods. Simultaneously, pressure threshold control eliminates the risk of oil leakage, and the service life of hydraulic components is significantly extended. Its core value lies in transforming the uncertainties of the harsh underground environment into controllable parameters, providing a reusable technological paradigm for the intelligentization of coal mine equipment, possessing both engineering practicality and promising prospects for industry promotion.

[0077] Secondly, the present invention also provides a self-moving tail leveling control device, such as... Figure 8 As shown, it includes: The determination module 201 is used to obtain the spatial pose of the self-moving tail leveling frame through an inertial gyroscope, and then calculate the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method.

[0078] Leveling module 202, used to control the opening degree of the servo valve connected to the leveling hydraulic cylinder based on the current working stage of the self-moving tail section, includes: During the cylinder raising phase, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. During the leveling phase, the support point of the leveling hydraulic cylinder at the current midpoint is selected as a fixed reference point, using the geometric center point of the self-moving tail as a reference. The displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted according to the desired displacement value. During the retraction phase, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil supplied by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

[0079] The present invention also provides a computer-readable storage medium storing a computer program that can be used to execute the above-described... Figure 1 The steps of the self-moving tail leveling control method provided.

[0080] This invention also provides a computer device. At the hardware level, the computer device includes a processor, an internal bus, a network interface, memory, and non-volatile memory, and may also include other hardware required for various operations. The processor reads the corresponding computer program from the non-volatile memory into the memory and then executes it to achieve the above-mentioned functions. Figure 1The steps of the self-moving tail leveling control method provided.

[0081] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0082] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0085] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the patent of the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A self-moving tail leveling control method, characterized in that, The method includes: Obtain the spatial pose of the self-moving tail leveling frame, and calculate the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method; Based on the current working stage of the self-moving tail section, the opening degree of the servo valve connected to the leveling hydraulic cylinder is controlled, including: During the cylinder raising phase, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. During the leveling phase, the geometric center point of the self-moving tail is used as a reference, and the support point of the leveling hydraulic cylinder at the current midpoint is selected as a fixed reference point. According to the desired displacement value, the displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted. During the retraction phase, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil provided by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

2. The method according to claim 1, characterized in that, The spatial pose includes pitch angle, roll angle, and yaw angle, and the calculation of the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method includes: Define the coordinates of the four corner support points when in a horizontal position; Based on pitch angle θ, roll angle φ, and yaw angle Construct the rotation matrix: ； The coordinates of the support point in the horizontal state are mapped to the current tilted coordinate system using a rotation matrix to obtain the theoretical Z-axis coordinates of the support point in the current tilted state. The desired displacement of each hydraulic cylinder is determined based on the measured displacement of the fixed reference point.

3. The method according to claim 1, characterized in that, During the leveling phase, a variable universe fuzzy PID control method based on a hybrid scaling factor is used to control the displacement of the pistons of each leveling hydraulic cylinder in asynchronous adjustment, including: Real-time calculation of the displacement error and error rate of the hydraulic cylinder piston between the actual displacement and the expected displacement; By using a hybrid scaling factor, the displacement error and the rate of change of error are scaled separately to obtain the adjusted input variables; The scaled input variables are input to the fuzzy controller, which infers based on the preset fuzzy rule table and outputs the PID parameter adjustment amount. The hybrid scaling factor is used as the output scaling factor to synchronously scale the adjustment amount of the PID parameters output by the fuzzy inference, and the final PID parameters are determined by the scaled PID parameter adjustment amount. The final PID parameters are used to generate a control signal to drive the servo valve and control the leveling hydraulic cylinder.

4. The method according to claim 3, characterized in that, The formula for calculating the hybrid scaling factor includes: Error scaling factor: ; Error rate of change scaling factor: ; in, For displacement error; The rate of change of error; This is a mixing coefficient, adjusted based on the relationship between the displacement error and a preset error threshold. , This is the adjustment coefficient for the functional part; For the first The membership degree of a fuzzy rule; For the first Output the scaling factor corresponding to each fuzzy rule.

5. The method according to claim 1, characterized in that, Back pressure control is performed during the cylinder lifting stage, including: Detect the pressure P2 in the rod chamber and the pressure P1 in the rodless chamber; Adjust the opening of the rod chamber valve to make P2 ≤ 0.4P1 - 0.2MPa.

6. The method according to claim 5, characterized in that, Speed ​​control during the retraction phase includes: Set velocity curve v ref =v0e −t / τ ; Where v0 is the initial retraction velocity, and τ is the velocity decay time constant; The return oil flow rate Q=A is adjusted by the rodless chamber regulating valve. rod v ref ; Among them, A rod This represents the cross-sectional area of ​​the piston.

7. The method according to claim 6, characterized in that, During the leveling phase, the retracted leveling hydraulic cylinder is operated as follows: The fully open rod chamber servo valve ensures that the rod chamber pressure is ≤0.2MPa; The opening degree of the rodless chamber servo valve is controlled to regulate the return oil flow. The oil return portion of the rodless chamber is injected into the rod chamber through the regeneration channel.

8. A self-moving tail leveling control device, characterized in that, The device includes: The determination module is used to obtain the spatial pose of the self-moving tail leveling frame through an inertial gyroscope, and then calculate the expected displacement values ​​of the leveling hydraulic cylinders at the four corners of the self-moving tail based on the three-dimensional space Euler angle method. The leveling module, used to control the opening of the servo valve connected to the leveling hydraulic cylinder based on the current working stage of the self-propelled tail section, includes: During the cylinder raising phase, the opening of the servo valve connected to the rodless chamber of the hydraulic cylinder is controlled, allowing hydraulic oil to enter the rodless chamber and drive the piston to extend to the initial set position. The opening of the servo valve connected to the rod chamber of the hydraulic cylinder is adjusted to allow oil return from the rod chamber and maintain the back pressure of the rod chamber below the set threshold. During the leveling phase, the support point of the leveling hydraulic cylinder at the current midpoint is selected as a fixed reference point, using the geometric center point of the self-moving tail as a reference. The displacement of the pistons of the other three leveling hydraulic cylinders is asynchronously adjusted according to the desired displacement value. During the retraction phase, the servo valve connected to the rod chamber of the hydraulic cylinder is placed in the fully open state, allowing the pressure oil supplied by the hydraulic pump to enter the rod chamber. The opening of the servo valve connected to the rodless chamber is controlled, allowing the oil in the rodless chamber to flow back to the oil tank and drive the piston rod to retract as needed.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the method described in any one of claims 1 to 7.

10. A computer device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method described in any one of claims 1 to 7.

Images