Coal rock identification based shearer system and height tracking controller design method

Abstract

The present application relates to a kind of coal rock identification-based shearer system and its height adjustment tracking controller design method.The system includes coal rock identification part, control system, height adjustment tracking controller, shearer drum height adjustment hydraulic system, drum and rocker arm;Control system converts the drum target height input by coal rock identification part into the expected displacement of height adjustment oil cylinder piston rod, and height adjustment tracking controller carries out displacement tracking control to drum by controlling shearer drum height adjustment hydraulic system;The method includes the following steps: establishing the state equation with shearer drum height adjustment hydraulic system as the research object;Establish height adjustment tracking controller including extended state observer;For parameter self-adapting, design adaptive law and non-discontinuous projection function to ensure its bounded;Control law is designed based on extended state observer and adaptive law.The present application realizes more accurate control according to the modern control theory based on state space equation, using system state information.

Description

Technical Field

[0001] This invention relates to the field of mining equipment technology; specifically, it relates to a coal mining machine system based on coal and rock identification and a design method for its height adjustment and tracking controller. Background Technology

[0002] Coal mining operations are complex and variable, facing challenges such as uneven coal and rock distribution, sudden changes in hardness, impacts from interbedded rock, and inherent strong nonlinearity in the system itself. These issues deteriorate the operational stability of the hydraulic system used for height adjustment, leading to reduced cutting accuracy and increased errors, severely hindering the development of unmanned and intelligent coal mining machines. Traditional linear control (such as conventional PID controllers) can easily achieve automatic cutting when operating conditions are stable and the geological undulations in the coal mine are minimal. However, the geological conditions in actual coal mines are often poor, and due to limitations in the performance of the height adjustment system, automatic cutting has not yet been widely adopted. Taking the MG750 / 1860-WD coal mining machine of China Coal Technology & Engineering Group Shanghai Co., Ltd. as an example, insufficient accuracy leads to cutting path deviations, requiring repeated adjustments and reducing efficiency by over 20%. When drum wear exceeds 5mm, cutting resistance increases by 20%–30%, further amplifying the control error of the hydraulic system (increasing by 10%–15%), creating a vicious cycle of "wear → increased load → decreased accuracy → wear". This necessitates exploring more advanced nonlinear control technologies to achieve high-precision control of the hydraulic system for adjusting the height of coal mining machines, thereby facilitating the development of coal mining machines towards unmanned and intelligent operation. Summary of the Invention

[0003] In view of this, the present invention provides a coal mining machine system based on coal and rock identification and a design method for its height adjustment and tracking controller, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0004] To achieve the aforementioned objectives, a first aspect of the present invention provides a design method for a height adjustment tracking controller for a coal mining machine system based on coal and rock identification, wherein the system includes a coal and rock identification part, a control part, a drive part, and a mechanical system; the control part includes a control system and a height adjustment tracking controller; the drive part includes a coal mining machine drum height adjustment hydraulic system; and the mechanical system includes a drum and a rocker arm. The hydraulic system for adjusting the height of the coal mining machine drum includes a control valve and a height-adjusting cylinder. The control valve controls the position of the piston rod of the height-adjusting cylinder. The height-adjusting cylinder drives the rocker arm to rise and fall through the extension and retraction of the piston rod, thereby adjusting the height of the drum. The coal and rock identification section inputs the target height of the drum to the control system; the control system calculates the desired displacement of the piston rod based on the target height and inputs the desired displacement to the height adjustment tracking controller; the height adjustment tracking controller sends a control signal to control the hydraulic system for adjusting the height of the coal mining machine drum, performs displacement tracking control on the height adjustment cylinder, and thus controls and tracks the height of the drum. The method includes the following steps: Establish a state equation for the hydraulic system for adjusting the height of the coal mining machine drum; For the aforementioned state equation, an elevation tracking controller including an extended state observer is established, which is capable of estimating the disturbances of the system; An adaptive law is designed for the parameters of the height-adjustment tracking controller, and a discontinuous projection function is defined to ensure that the parameter adaptation is bounded. Based on the extended state observer and the adaptive law, the control law of the height-adjustment tracking controller is designed.

[0005] In the method described above, optionally, the state equation is: , in, , and Let be the displacement of the piston rod and its derivative, respectively. and The speed of the hydraulic cylinder and its derivative are adjusted. and These refer to the output force of the adjustable hydraulic cylinder and its derivative. To increase the output force of the hydraulic cylinder; For load quality; For interference force; , To increase the viscous damping coefficient of the hydraulic cylinder; , The elastic modulus of hydraulic oil. The flow gain coefficient of the control valve. , The flow coefficient of the control valve is... The valve core area gradient of the control valve. This refers to the dynamic proportional gain coefficient of the control valve. The density of the hydraulic fluid; , The effective working area of ​​the rodless chamber of the height-adjusting cylinder; , The effective working area of ​​the rod chamber of the height-adjusting cylinder; , To increase the internal leakage coefficient of the hydraulic cylinder; , , The effective volume of the rodless chamber of the height-adjusting cylinder. , The initial volume of the rodless chamber of the height-adjusting cylinder; , , The effective volume of the rod chamber of the height adjustment cylinder. , The initial volume of the rod-side chamber of the height-adjusting cylinder; , To increase the pressure in the rodless chamber of the hydraulic cylinder, To increase the pressure in the rod chamber of the hydraulic cylinder; , For modeling error, , and The respective and stated Modeling error; , Input a signal to the control valve. , , For symbolic functions, Increase the oil supply pressure of the hydraulic system for the coal mining machine drum. Increase the return oil pressure of the hydraulic system for the coal mining machine drum.

[0006] In the method described above, optionally, the input control signal of the control valve and the position of the height-adjusting cylinder are used as the state variables of the state equation; the extended state observer observes the load disturbance and output speed of the height-adjusting cylinder, and the model of the extended state observer is: in, It is the gain coefficient of the extended state observer; For the The observation error, ; Uncertain parameters The estimate; For adaptive function regression variables, , For the desired speed; For the The observed values.

[0007] In the method described above, optionally, the discontinuous projection function is: , in, =1, 2, 3, 4, 5, 6; For matrix The item; The adaptive law is: , in, For adaptive gain, ; The adaptive function is... It has the following properties: , in To estimate the error, ; The adaptive function for: , in, For virtual state variables, , The adaptive compensation control law is based on the aforementioned state equation. As an auxiliary error variable, For feedback gain coefficient, For the error state variables of the extended state observer, , , For the uncertain parameter The upper realm, This is for tracking error.

[0008] In the method described above, optionally, the design of the control law includes the following steps: Define a set of error variables: , in, Let be the displacement error of the piston rod. , Let be the desired displacement of the piston rod. For virtual state variables, and For positive feedback gain coefficient, For a first-order virtual control law, the auxiliary error variable for ; The As a dummy variable, the Designed as follows: , in, , For parameter adaptive feedforward compensation control law For robust control laws; Differentiation yields the above. Dynamic expressions: , in, , The error state variable of the extended state observer; The Divided into two items: , in, For the nominal model used in stable systems, For the estimation error used to stabilize mismatched disturbances, dynamic and parameter adaptive methods, , The feedback gain is a normal number. The expression is obtained by rearranging the expressions as follows: , in, The error state variable of the extended state observer; The final actual control law is designed as follows: , , , in, Used for the nominal model of a stable system. , It is a normal gain feedback. Used to control the model uncertainty of the system and balance the parameter uncertainty of the system. The following conditions must be met: , , in, It is a positive number, representing the... Upper bound of error estimation Let it be an arbitrarily small constant; The design described for ,in, Given a positive constant feedback gain, we obtain the following expression: , , in, It is a positive gain coefficient. , , and It is bounded, and the boundary is: , in, and The respective and stated The coefficient has an upper bound and is a positive number.

[0009] In the method described above, optionally, the first-order virtual control law is obtained using a Levant differentiator. The time derivative of the Levant differentiator is given by the following structure: , in, For input signal, For output signal, For the initial value, The derivative of the output signal. and is the gain coefficient of the Levant differentiator.

[0010] Optionally, in the method described above, the method further includes performing stability verification, which includes the following steps: Define the Lyapunov function: ; The derivative of the Lyapunov function is calculated as follows: , The derivative satisfies the following inequality: ; Define a symmetric matrix : , in, , , , All are positive numbers. , , , ; Based on the aforementioned symmetric matrix and applying Young's inequality, the following differential inequality is obtained: , in, , Let be the smallest eigenvalue of the symmetric matrix. , ; Solving the differential inequality yields the convergence error of the Lyapunov function: , The stability of the system is determined by evaluating the convergence error.

[0011] To achieve the aforementioned objective, a second aspect of the present invention provides a coal mining machine system based on coal and rock identification, wherein the system includes a coal and rock identification part, a control part, a drive part, and a mechanical system, the control part includes a control system and a height adjustment tracking controller, the drive part includes a coal mining machine drum height adjustment hydraulic system, and the mechanical system includes a drum and a rocker arm; The hydraulic system for adjusting the height of the coal mining machine drum includes a control valve and a height adjustment cylinder. The control valve is a servo valve or a proportional valve. The control valve controls the position of the piston rod of the height adjustment cylinder. The height adjustment cylinder drives the rocker arm to rise and fall through the extension and retraction of the piston rod, thereby adjusting the height of the drum. The coal and rock identification unit sends the target height of the drum to the control system; the control system calculates the desired displacement of the piston rod based on the target height and inputs the desired displacement to the height adjustment tracking controller; the height adjustment tracking controller sends a control signal to control the hydraulic system for adjusting the height of the coal mining machine drum, performs displacement tracking control on the height adjustment cylinder, and thus controls and tracks the height of the drum. The height tracking controller is designed using the method described in any of the first aspects above.

[0012] In the system described above, optionally, the coal and rock identification part includes a cutting force response detection device, a position detection device, a first data acquisition device, a second data acquisition device, and an automatic coal and rock interface identification system, and the driving part also includes a D / A converter and an amplifier; The cutting force response detection device detects the cutting force of the drum, the first data acquisition device collects the detection data of the cutting force response detection device and transmits it to the coal-rock interface automatic identification system, the coal-rock interface automatic identification system transmits the coal-rock interface automatic identification result to the control system, the position detection device detects the position information of the drum, and the second data acquisition device collects the detection data of the position detection device and transmits it to the control system. The height adjustment tracking controller is connected to the D / A converter, the D / A converter is connected to the amplifier, the amplifier is connected to the coal mining machine drum height adjustment hydraulic system, the coal mining machine drum height adjustment hydraulic system is connected to the rocker arm, and the rocker arm is connected to the drum. The control signal issued by the height adjustment tracking controller is converted by the D / A converter and amplified by the amplifier to drive the operation of the coal mining machine drum height adjustment hydraulic system.

[0013] In the system described above, optionally, the hydraulic system for adjusting the height of the coal mining machine drum also includes an oil tank, a filter, a motor, a hydraulic pump, a safety valve, a hydraulic lock, and a displacement sensor. The oil tank is connected to the filter, the safety valve, and the control valve. The filter and the motor are connected to the hydraulic pump. The hydraulic pump, the safety valve, and the amplifier are connected to the control valve. The control valve is connected to the hydraulic lock. The hydraulic lock is connected to the height adjustment cylinder. The height adjustment cylinder is connected to the rocker arm. The displacement sensor detects the displacement of the piston rod of the height adjustment cylinder.

[0014] The present invention relates to a height tracking controller design method for a coal mining machine system based on coal and rock identification. Based on modern control theory based on state-space equations, this method utilizes system state information to achieve more precise control.

[0015] The present invention further provides a coal mining machine system based on coal and rock identification, and therefore the coal mining machine system also has the above-mentioned advantages. Attached Figure Description

[0016] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings: Figure 1 This is a schematic block diagram of an embodiment of the coal mining machine system based on coal and rock identification of the present invention; Figure 2 This is a schematic diagram of the hydraulic system for adjusting the height of the coal mining machine drum, an embodiment of the coal mining machine system based on coal and rock identification of the present invention. Figure 3 This is a flowchart illustrating an embodiment of the design method for a height adjustment tracking controller of a coal mining machine system based on coal and rock identification according to the present invention. Figure 4 This is a schematic diagram of a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention; Figure 5 This is a schematic diagram of the response curves of different controllers under constant load conditions in a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention. Figure 6 This is a schematic diagram of the response curves of different controllers under variable load conditions in a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention. Figure 7 This is a schematic diagram of the load disturbance observation curve of the extended state observer under variable load conditions in a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention. Figure 8 This is a schematic diagram of the hydraulic cylinder speed observation curve under variable load conditions in a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention. Figure 9 This is a schematic diagram of the adaptive parameter curves of the coal mining machine system based on coal and rock identification under variable load conditions in a simulation experiment of the present invention.

[0017] Reference numerals: 1-Oil tank; 2-Filter; 3-Motor; 4-Hydraulic pump; 5-Safety valve; 6-Servo valve; 7-Servo amplifier; 8-Hydraulic lock; 9-Height adjustment cylinder; 10-Rocker arm; 11-Drum; 12-Accumulator; 13-Co-simulation interface; 14-Rodless chamber pressure sensor; 15-Rod chamber pressure sensor; 16-Displacement sensor; 17-Velocity sensor; 18-Simulated load. Detailed Implementation

[0018] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the coal mining machine system based on coal and rock identification and its height adjustment tracking controller design method of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.

[0019] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0020] It should also be noted that 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. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0021] Figure 1 This is a schematic block diagram of an embodiment of the coal mining machine system based on coal and rock identification of the present invention.

[0022] like Figure 1 As shown, the coal mining machine system includes a coal and rock identification section, a control section, a drive section, and a mechanical system.

[0023] Regarding the coal and rock identification section, such as Figure 1 As shown, it includes a cutting force response detection device, a position detection device, a data acquisition device, and an automatic coal-rock interface identification system, wherein the first data acquisition device is connected to the cutting force response detection device, and the second data acquisition device is connected to the position detection device.

[0024] Because coal and rock have different mechanical and physical properties, the response characteristics exhibited by coal mining machines during cutting also differ. Based on this principle, characteristic parameters of the cutting state can be monitored, such as vibration signals, acoustic emission signals, circuit signals, and cutting torque, to determine the coal and rock cutting state. In this embodiment, monitoring cutting mechanical signals is chosen to achieve coal and rock identification. Figure 1 As shown, the cutting force response detection device detects the force on the coal mining machine drum, and the first data acquisition device collects the detected cutting force-related data and provides this data to the coal-rock interface automatic identification system. Because of the different hardness of coal and rock, the actual torque experienced by the drum differs when cutting coal and rock layers. Therefore, by monitoring the force on the drum, automatic identification of the coal-rock interface during the cutting process can be achieved. In other embodiments, besides using the above-mentioned method for coal-rock identification based on characteristic signals during the mining process, other existing coal-rock interface identification methods can also be used, such as coal-rock identification technologies based on infrared thermal imaging, ultrasonic detection, electromagnetic wave detection, or image feature recognition.

[0025] Based on the identification results of the coal-rock interface, the target height of the coal mining machine drum can be calculated in real time and input into the control unit to provide a basis for subsequent control. Automatic identification of the coal-rock interface can avoid ineffective rock cutting by the coal mining machine, extend the service life of the coal mining machine, reduce reliance on manual judgment of the coal-rock interface, cope with complex working conditions, and improve coal mining efficiency.

[0026] Meanwhile, the position detection device monitors the actual height of the roller, and the second data acquisition device collects this data and provides it to the control unit to provide a basis for subsequent control.

[0027] Regarding the control section. Figure 1The control system, height adjustment tracking controller, and their control signals are shown. The control system processes the aforementioned automatic coal-rock interface identification results, drum target height, and actual height, and generates a desired displacement signal to the height adjustment tracking controller. The height adjustment tracking controller generates a control signal and transmits it to the drive unit to perform displacement tracking control on the hydraulic system for adjusting the height of the coal mining machine drum in the drive unit.

[0028] Regarding the driver part, such as Figure 1 As shown, it includes a D / A converter, an amplifier, and a coal mining machine drum height adjustment hydraulic system (i.e., the coal mining machine height adjustment hydraulic system shown in the figure). The height adjustment tracking controller is connected to the D / A converter, the D / A converter is connected to the amplifier, and the amplifier is connected to the coal mining machine drum height adjustment hydraulic system. The control signal sent by the height adjustment tracking controller is converted and amplified by the D / A converter and the amplifier, driving the operation of the coal mining machine drum height adjustment hydraulic system.

[0029] Regarding mechanical systems, such as Figure 1 As shown, it includes a drum, a rocker arm connected to the drum, and a cutting load. The cutting load is the load borne by the drum when cutting coal and rock. The rocker arm is driven by the hydraulic system for adjusting the height of the coal mining machine drum, which in turn drives the drum to perform the cutting operation. At the same time, the information on the drum cutting load is fed back to the aforementioned detection device.

[0030] like Figure 1 As shown, the coal mining machine system is traction-driven by a traction mechanism. The traction mechanism can receive drum position detection data from the position detection device, as well as the converted and amplified control signal, to realize the traction movement of the coal mining machine.

[0031] like Figure 1 As shown, the system can also monitor the system's operation through manual observation, including monitoring the cutting operation of the coal mining machine's drum, and can also intervene in the traction mechanism, the hydraulic system for adjusting the height of the coal mining machine's drum, etc.

[0032] The aforementioned system, through the coordinated operation of the coal and rock identification section, control section, drive section, and mechanical system, enables automatic height adjustment of the coal mining machine drum, thereby improving the intelligence and efficiency of coal mining operations.

[0033] Figure 2 This is a schematic diagram of the hydraulic system for adjusting the height of the coal mining machine drum, which is an embodiment of the coal mining machine system based on coal and rock identification of the present invention.

[0034] Figure 2 The diagram shows the oil tank 1, filter 2, motor 3, hydraulic pump 4, safety valve 5, servo valve 6, hydraulic lock 8, and height adjustment cylinder 9 of the hydraulic system for adjusting the drum of the coal mining machine. It also shows the servo amplifier 7 of the drive section and the height adjustment tracking controller (i.e.,...) of the control section. Figure 2The system includes a controller and a rocker arm 10 and a roller 11. The oil tank 1 is connected to the filter 2, safety valve 5, and servo valve 6. The filter 2 and motor 3 are connected to the hydraulic pump 4. The hydraulic pump 4, safety valve 5, and servo amplifier 7 are connected to the servo valve 6. The servo valve 6 is connected to the hydraulic lock 8. The hydraulic lock 8 is connected to the height adjustment cylinder 9. The height adjustment cylinder 9 is connected to the rocker arm 10.

[0035] The hydraulic system for adjusting the height of the coal mining machine drum also includes a displacement sensor (not shown). The displacement sensor detects the displacement of the piston rod of the height-adjusting cylinder 9, and the detection signal is transmitted to the height-adjusting tracking controller.

[0036] As previously described, the control valve and amplifier in this embodiment are servo valve 6 and servo amplifier 7. In other embodiments, servo valve 6 and servo amplifier 7 may be replaced by proportional valve and proportional amplifier.

[0037] like Figure 2 As shown, the height adjustment cylinder 9, which is the valve-controlled hydraulic cylinder in this hydraulic system, adjusts the height of the drum 11 by extending and retracting its piston rod to raise and lower the rocker arm 10. Therefore, the height adjustment tracking controller can control and track the height of the drum 11 by controlling and tracking the extension displacement of the height adjustment cylinder 9. Specifically, the coal-rock interface automatic identification system (not shown) calculates the target height of the drum 11 based on the coal-rock identification results. The control system (not shown) converts the target height of the drum 11 into the corresponding desired position of the piston rod of the height adjustment cylinder 9 and inputs the desired position into the height adjustment tracking controller.

[0038] Figure 3 This is a flowchart illustrating an embodiment of the height adjustment tracking controller design method for a coal mining machine system based on coal and rock identification according to the present invention.

[0039] like Figure 3 As shown, this design method first transforms the hydraulic system for adjusting the height of the coal mining machine drum into a mathematical model, specifically into a third-order state equation. This mathematical mapping makes the complex physical system computable and analyzable, paving the way for the subsequent design of advanced control algorithms. Furthermore, considering the three major control challenges of the hydraulic system for adjusting the height of the coal mining machine drum—strong nonlinearity, slowly varying parameters, and stochastic load disturbances—a "three-in-one" control algorithm based on modern control theory is designed, employing robust control laws, parameter adaptive laws, and an Extended State Observer (ESO).

[0040] This method can be used to design the above. Figure 1 , Figure 2 The height tracking controller for the described coal mining machine system. Exemplarily, the following are the specific steps of this design method.

[0041] Step S1: Taking the hydraulic system for adjusting the height of the coal mining machine drum (e.g., the hydraulic system for adjusting the height of the Shanghai Coal Technology MG750 / 1860-WD coal mining machine drum) as the research object, the following state equation is established: in, , and These refer to the displacement of the piston rod of hydraulic cylinder 9 and its derivative. and To increase the speed of cylinder 9 and its derivative, and The output force and its derivative of hydraulic cylinder 9 are adjusted accordingly. To increase the output force of hydraulic cylinder 9; For load quality; For interference force; , To increase the viscous damping coefficient of hydraulic cylinder 9; , The elastic modulus of hydraulic oil. To control the flow gain coefficient of the valve, , To control the valve flow coefficient, To control the valve core area gradient, This refers to the dynamic proportional gain coefficient of the control valve. The density of the hydraulic fluid; , To increase the effective working area of ​​the rodless chamber of cylinder 9; , To increase the effective working area of ​​the rod chamber of hydraulic cylinder 9; , To increase the internal leakage coefficient of hydraulic cylinder 9; , , To increase the effective volume of the rodless chamber of cylinder 9, , To increase the initial volume of the rodless chamber of cylinder 9; , , To increase the effective volume of the rod chamber of hydraulic cylinder 9, , To increase the initial volume of the rod chamber of hydraulic cylinder 9; , To increase the pressure in the rodless chamber of cylinder 9, To increase the pressure in the rod chamber of hydraulic cylinder 9; , For modeling error, , and They are respectively and Modeling error; , Input signal to control valve, , , For symbolic functions, To increase the oil supply pressure of the hydraulic system for the coal mining machine drum, Increase the return oil pressure of the hydraulic system for the coal mining machine drum.

[0042] Step S2: Based on the state equation constructed in step S1, a height adjustment tracking controller is established using the input control signal of the control valve and the position of the height adjustment cylinder 9 as state variables. This height adjustment tracking controller is an adaptive robust controller (ARC-ESO) including an extended state observer. The extended state observer observes the load disturbance and output speed of the height adjustment cylinder 9. The model of the extended state observer is as follows: in, It is the observer gain coefficient; for The observation error, ; Uncertain parameters The estimate; For adaptive function regression variables, , For the desired speed; for Observed values. In the adaptive function regression variables above, the expected velocity is used. Alternative This can avoid the amplification of measurement noise inside the observer and avoid the coupling between parameter adaptation and the observer's state estimation.

[0043] Step S3: Introduce a parameter adaptive algorithm into the controller design. Let... Represented as an uncertain parameter The estimate, This is expressed as the estimation error, i.e. To ensure that the parameters are adaptively bounded, a discontinuous projection function is defined: In the formula, =1, 2, 3, 4, 5, 6; Representative matrix The The adaptive law is designed as follows: In the formula, For adaptive gain, ; Let be an adaptive function, for any adaptive function They all have the following properties: The adaptive law can be designed as follows: In the formula, For virtual state variables, ,in The adaptive compensation control law is based on the aforementioned state equation. As an auxiliary error variable similar to a sliding surface, For feedback gain coefficient, To extend the error state variables of the state observer, , , Uncertain parameters The upper realm, This is for tracking error.

[0044] The hydraulic system for adjusting the height of the coal mining machine drum is relatively complex and subject to significant load interference, with some parameters changing as the machine's position changes. Introducing a parameter adaptive law can reduce parameter uncertainty, improve robustness and anti-interference capabilities, and thus enhance overall tracking performance.

[0045] Step S4: Based on the previous steps, design and adjust the control law of the tracking controller.

[0046] Define a set of error variables: In the formula, Let be the system displacement error, where To increase the desired displacement of the piston rod in hydraulic cylinder 9, and For virtual state variables, and For positive feedback gain coefficient, It is a first-order virtual control law. By introducing an auxiliary error variable similar to a sliding surface. This allows the system to quickly achieve its gradual goals.

[0047] Will Treat it as a dummy variable. Redesigned as: , In the formula, , For parameter adaptive feedforward compensation control law This is a robust control law.

[0048] Taking its derivative, we get Dynamic expressions: In the formula, , The error state variables for the extended state observer.

[0049] Because both the model uncertainty and the estimated values ​​of the adaptive parameters have errors compared to their actual values, It can be divided into two items: In the formula, For the nominal model used in stable systems, For the estimation error used to stabilize mismatched disturbances, dynamic and parameter adaptive methods, ,in The feedback gain is a normal number.

[0050] The expression is obtained by rearranging the expressions as follows: In the formula, Let be the error state variable of the extended state observer.

[0051] The final actual control law can be designed. : In the formula, As described in step S3, it is a model-based adaptive compensation control law; For the nominal model of a stable system, its form is: ,in It is a normal gain feedback; Model uncertainties for control systems and parameter uncertainties for equilibrium systems, It can be any function that satisfies the following conditions: in, A positive number represents Upper bound of error estimation Let be an arbitrarily small constant.

[0052] therefore, It can be designed in the following form: , In the formula, Since the feedback gain is positive and constant, the following expression can be obtained: In the formula, This is consistent with step S3.

[0053] In addition, the following expression can also be obtained: In the formula, It is a positive gain coefficient. Since the input signal and its derivative are both bounded, the parameter perturbation is also bounded. and It is bounded, and its boundary is: In the formula, , , and They are respectively and The coefficient has an upper bound and is positive.

[0054] The controller design method described above establishes a mathematical model of the hydraulic system for adjusting the height of a coal mining machine drum based on a valve-controlled hydraulic cylinder. Addressing the issues of significant susceptibility to external disturbances and low control accuracy, an Adaptive Robust Control (ARC) algorithm based on an extended state observer is designed. The extended state observer can estimate unknown disturbances in real time and feed them back to the controller for compensation, while also reducing the use of sensors. Under this design, the height adjustment tracking controller receives the desired tracking signal, uses the extended state observer to estimate and compensate for unknown model uncertainties in the system, and in the adaptive model compensator design of the observer and controller, the actual state values ​​are replaced with the corresponding desired signal values ​​to reduce measurement noise interference. Through adaptive control parameter perturbation, robust control weakens uncertainties that cannot be obtained through modeling. Therefore, this approach can solve or at least alleviate the problems of parameter uncertainty, external unknown load interference, and measurement noise in the electro-hydraulic system for adjusting the height of a coal mining machine drum.

[0055] Furthermore, in the aforementioned step S4, the Levant differentiator is used to obtain... The time derivative can be used to avoid differential explosion. The structure of the Levant differentiator is as follows: , In the above formula, For input signal, For output signal, That is, the derivative of the output signal. for initial value, and This is the gain coefficient of the differentiator.

[0056] Furthermore, the method also includes step S5, which involves constructing a Lyapunov function to evaluate the evolution of the system state, thereby determining the stability of the system and verifying the stability of the control effect. For example, the specific steps of S5 are as follows.

[0057] Define the following Lyapunov functions: Differentiating the above equation, we get: The above formula can be transformed into: In the formula, , .

[0058] Applying Young's inequality, we get: Define the following symmetric matrix: In the above formula, , , , All are positive numbers. , , , .

[0059] based on , It can be converted to: In the formula, , ,make ,but: In the formula, for The smallest eigenvalue. Solving the above equation, we get: The above equation represents the convergence error of the Lyapunov function. The convergence speed and final tracking error of the system depend on the matrix. By determining the magnitude of the eigenvalues, appropriate system parameters can be selected to ensure that the system converges to the minimum tracking error at a specified speed, thereby ensuring system stability.

[0060] The method described in this embodiment, combined with modern control theory, accurately describes the characteristics of the hydraulic system for adjusting the height of the coal mining machine drum, designs an adaptive algorithm, and achieves high-precision displacement control of the hydraulic system for adjusting the height of the coal mining machine drum under complex interference conditions. This helps to improve the operational performance of coal mining hydraulic equipment and facilitates the intelligent upgrading of coal mining machines.

[0061] Figure 4 This is a schematic diagram of a simulation experiment of the coal mining machine system based on coal and rock identification according to the present invention.

[0062] This experiment employed co-simulation using MATLAB / Simulink and AMESim. AMESim was used to build a simulation model, transforming the mechanical and hydraulic components of the coal mining machine drum height adjustment hydraulic system into simulable modules. MATLAB / Simulink facilitated rapid algorithm deployment and online parameter adjustment, providing a reliable and efficient technical means to verify algorithm effectiveness and optimize control strategies.

[0063] like Figure 4 As shown, the simulation model includes an oil tank 1, a motor 3, a hydraulic pump 4, a safety valve 5, a servo valve 6, a hydraulic lock 8, a height adjustment cylinder 9, an accumulator 12, a co-simulation interface 13, a rodless chamber pressure sensor 14, a rod chamber pressure sensor 15, a displacement sensor 16, a speed sensor 17, and a simulated load 18. The accumulator 12 is connected to the hydraulic pump 4, safety valve 5, and servo valve 6. The displacement sensor 16, speed sensor 17, rodless chamber pressure sensor 14, and rod chamber pressure sensor 15 detect the displacement, speed, and pressure of the two chambers of the height adjustment cylinder 9, respectively. The co-simulation interface 13 simulates a height adjustment tracking controller, outputting the displacement, speed, and pressure of the two chambers of the height adjustment cylinder 9 as variables to MATLAB / Simulink. The output signal from MATLAB / Simulink is used as the excitation signal for the servo valve 6 to control its opening. The connection methods of the remaining components can be referenced in the diagram. Figure 2 The description of the hydraulic system for adjusting the height of the coal mining machine drum is shown below and will not be repeated here. The hydraulic parameters are set as shown in Table 1 below.

[0064] Table 1 Simulation Model Parameters The hydraulic cylinder in Table 1 is the height adjustment cylinder 9, and the same applies below.

[0065] The following combination Figure 5-9 Explain the simulation results of this simulation experiment.

[0066] To verify the effectiveness of the adaptive robust controller (ARC-ESO) based on the extended state observer in some embodiments of the present invention, adaptive robust (ARC) and traditional PID controllers were selected for comparison. During co-simulation, a ramp target signal was set to simulate the roller lifting process, and the system's bidirectional positioning capability and anti-interference capability were examined.

[0067] First, the positioning capability of the drum during the rising and falling phases is verified, and the performance of each controller during these phases is compared. The error between the actual position and the target position of the hydraulic cylinder in the drum height adjustment hydraulic system after approaching the target positioning height is called the steady-state error. Furthermore, the maximum error of the cylinder during the steady-state process after approaching the target position is called the maximum tracking error. These two indicators are important references for evaluating the positioning capability of the height adjustment system. To quantitatively analyze the control effects of the aforementioned three controllers during the rising and falling phases and to ensure the fairness of the comparison environment, the maximum tracking error and steady-state error are introduced to evaluate the performance of different control algorithms. In the joint simulation, for example, the target signal is set as a ramp signal. The system starts rising at 1 second, reaches the target height of 200mm at 12 seconds and maintains it, starts falling at 17 seconds, returns to 100mm at 22 seconds and maintains it, thus examining the system's bidirectional positioning capability. The response curves of different controllers under this simulation are shown below. Figure 5 As shown.

[0068] Combination Figure 5 Under the same operating conditions, during the lifting process of hydraulic cylinder 9, the maximum tracking errors of the three control algorithms—ARC-ESO (i.e., ESO+ARC in the figure), ARC, and PID—were 0.24mm, 0.44mm, and 1.1mm, respectively, and the steady-state errors were 3.5×10⁻⁶. -3 mm, 5.8×10 -3 mm and 0.24mm; during the descent of the lifting cylinder 9, the maximum errors of the three control algorithms, ARC-ESO, ARC, and PID, were 0.25mm, 0.48mm, and 0.99mm, respectively, and the steady-state errors were 2.6×10 mm and 0.24mm, respectively. -3 mm, 4.8×10 -3 mm and 9.6×10 -2 mm. Compared to traditional PID algorithms, ARC-ESO can reduce the maximum error during the ascent and descent processes by 78.2% and 75.7%, respectively, and the steady-state error during the ascent and descent processes by 98% and 94.3%, respectively. Overall, ARC-ESO can significantly improve the system's positioning capability and effectively enhance cutting efficiency.

[0069] Then, the anti-load interference capability was verified. During actual operation, the force on the cutting section of the coal mining machine changes frequently. The positioning capability verification above simulated a working condition where the coal quality is good and there are almost no sudden changes in interference force. Therefore, the following verification of the anti-interference capability of the ARC-ESO controller is conducted under actual working conditions. An interference-simulated load 18 was added to the height adjustment system to verify the performance of each controller. During this simulation, the position response curve of the height adjustment cylinder 9 is as follows: Figure 6 As shown, Figure 7 and Figure 8 These are schematic diagrams showing the comparison between observed and actual values ​​of external disturbances and cylinder speed observed through the extended state observer. Figure 9 This is a schematic diagram of the adaptive parameter curve.

[0070] Depend on Figure 6 It can be seen that during the rising phase, the system is affected by disturbed loads, and the position of the hydraulic cylinders of all three controllers fluctuates to some extent. The maximum tracking errors of the ARC-ESO, ARC, and PID control algorithms are 0.26mm, 0.67mm, and 1.5mm, respectively. During the hold phase from 14s to 16s, the maximum errors are 0.12mm, 0.4mm, and 0.9mm, respectively. From the perspective of maximum tracking error, in the rising and hold phases, the ARC-ESO control effect is 83.7% and 86.7% higher than PID, respectively. This is mainly because PID only controls based on tracking error, considering only the impact of input and output on the entire system. ARC-ESO, through its extended state observer, can provide real-time feedback on the disturbed loads of the rising system and effectively compensate for them, thus exhibiting better control performance. Therefore, regardless of the phase, ARC-ESO can effectively suppress the influence of load disturbances, ensuring stable system operation and allowing the coal mining machine to maintain precise cutting even under conditions of mixed coal and rock and sudden load changes.

[0071] from Figure 7 and Figure 8 It can be seen that the extended state observer can effectively monitor the system's load disturbances and speed. The observation results directly demonstrate this: when disturbances change slowly, it can accurately observe a given disturbance value; when disturbances change abruptly or frequently, although there are errors, it can capture the trend. This indicates that the extended state observer can effectively sense external load disturbances, enabling the controller to compensate for them in real time, providing technical support for reliable mining under complex conditions.

[0072] Figure 9 This demonstrates the effect of the parameter adaptive law on the adaptive adjustment of various parameters of the tracking controller under simulated variable load conditions, including the aforementioned... - The parameter estimation curve. Some parameters of the coal mining machine system will change with time and load disturbances. Figure 9This demonstrates that the height tracking controller can actively adapt to changes in operating conditions through parameter adaptive laws.

[0073] The above joint simulation results show that the adaptive robust controller (ARC-ESO) based on extended state observer in some embodiments of the present invention can eliminate the effects of load disturbances and enable the system to accurately track the set position of the hydraulic system for adjusting the height of the coal mining machine drum.

[0074] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. A design method for a height adjustment tracking controller for a coal mining machine system based on coal and rock identification, characterized in that, The system includes a coal and rock identification part, a control part, a drive part and a mechanical system. The control part includes a control system and a height adjustment tracking controller. The drive part includes a coal mining machine drum height adjustment hydraulic system. The mechanical system includes a drum (11) and a rocker arm (10). The hydraulic system for adjusting the height of the coal mining machine drum includes a control valve and a height adjustment cylinder (9). The control valve controls the position of the piston rod of the height adjustment cylinder (9). The height adjustment cylinder (9) drives the rocker arm (10) to rise and fall through the extension and retraction of the piston rod, thereby adjusting the height of the drum (11). The coal and rock identification section inputs the target height of the drum (11) to the control system; the control system calculates the expected displacement of the piston rod according to the target height and inputs the expected displacement to the height adjustment tracking controller; the height adjustment tracking controller sends a control signal to control the hydraulic system for adjusting the height of the coal mining machine drum, performs displacement tracking control on the height adjustment cylinder (9), and then controls and tracks the height of the drum (11); The method includes the following steps: Establish a state equation for the hydraulic system for adjusting the height of the coal mining machine drum; For the aforementioned state equation, an elevation tracking controller including an extended state observer is established, which is capable of estimating the disturbances of the system; An adaptive law is designed for the parameters of the height-adjustment tracking controller, and a discontinuous projection function is defined to ensure that the parameter adaptation is bounded. Based on the extended state observer and the adaptive law, design the control law for the height-adjustment tracking controller; The state equation is as follows: ， in, , and Let be the displacement of the piston rod and its derivative, respectively. and The speed of the adjustable cylinder (9) and its derivative, and The output force and its derivative of the height-adjusting cylinder (9) are respectively. To increase the output force of the hydraulic cylinder (9); For load quality; For interference force; , The viscous damping coefficient of the oil cylinder (9) is adjusted accordingly; , The elastic modulus of hydraulic oil. The flow gain coefficient of the control valve. , The flow coefficient of the control valve is... The valve core area gradient of the control valve. This refers to the dynamic proportional gain coefficient of the control valve. The density of the hydraulic fluid; , The effective working area of ​​the rodless chamber of the height-adjusting cylinder (9); , The effective working area of ​​the rod chamber of the height-adjusting cylinder (9); , The internal leakage coefficient of the oil cylinder (9) is increased; , , The effective volume of the rodless chamber of the height adjustment cylinder (9) is... , The initial volume of the rodless chamber of the height adjustment cylinder (9); , , The effective volume of the rod chamber of the height adjustment cylinder (9) is... , The initial volume of the rod chamber of the height adjustment cylinder (9); , To adjust the pressure in the rodless chamber of the hydraulic cylinder (9), To adjust the pressure in the rod chamber of the hydraulic cylinder (9); , For modeling error, , and The respective and stated Modeling error; , Input a signal to the control valve. , , For symbolic functions, Increase the oil supply pressure of the hydraulic system for the coal mining machine drum. Increase the return oil pressure of the hydraulic system for the coal mining machine drum.

2. The method as described in claim 1, characterized in that, The input control signal of the control valve and the position of the height-adjusting cylinder (9) are used as the state variables of the state equation; the extended state observer observes the load disturbance and output speed of the height-adjusting cylinder (9), and the model of the extended state observer is: in, It is the gain coefficient of the extended state observer; For the The observation error, ; Uncertain parameters The estimate; For adaptive function regression variables, , For the desired speed; For the The observed values.

3. The method as described in claim 2, characterized in that, The discontinuous projection function is: ， in, =1, 2, 3, 4, 5, 6; For matrix The item; The adaptive law is: ， in, For adaptive gain, ; The adaptive function is... It has the following properties: ， in To estimate the error, ; The adaptive function for: ， in, For virtual state variables, , The adaptive compensation control law is based on the aforementioned state equation. As an auxiliary error variable, For feedback gain coefficient, For the error state variables of the extended state observer, , , For the uncertain parameter The upper realm, This is for tracking error.

4. The method as described in claim 3, characterized in that, The design of the control law includes the following steps: Define a set of error variables: ， in, Let be the displacement error of the piston rod. , Let be the desired displacement of the piston rod. For virtual state variables, and For positive feedback gain coefficient, For a first-order virtual control law, the auxiliary error variable for ; The As a dummy variable, the Designed as follows: ， in, , For parameter adaptive feedforward compensation control law For robust control laws; Differentiation yields the above. Dynamic expressions: ， in, , The error state variable of the extended state observer; The Divided into two items: ， in, For the nominal model used in stable systems, For the estimation error used to stabilize mismatched disturbances, dynamic and parameter adaptive methods, , The feedback gain is a normal number. The expression is obtained by rearranging the expressions as follows: ， in, The error state variable of the extended state observer; The final actual control law is designed as follows: ， ， ， in, Used for the nominal model of a stable system. , It is a normal gain feedback. Used to control the model uncertainty of the system and balance the parameter uncertainty of the system. The following conditions must be met: ， ， in, It is a positive number, representing the... Upper bound of error estimation Let it be an arbitrarily small constant; The design described for ,in, Given a positive constant feedback gain, we obtain the following expression: ， ， in, It is a positive gain coefficient. , , and It is bounded, and the boundary is: ， in, and The respective and stated The coefficient has an upper bound and is a positive number.

5. The method as described in claim 4, characterized in that, The first-order virtual control law is obtained using a Levant differentiator. The time derivative of the Levant differentiator is given by the following structure: ， in, For input signal, For output signal, For the initial value, The derivative of the output signal. and is the gain coefficient of the Levant differentiator.

6. The method as described in claim 4, characterized in that, The method further includes stability verification, which includes the following steps: Define the Lyapunov function: ； The derivative of the Lyapunov function is calculated as follows: ， The derivative satisfies the following inequality: ； Define a symmetric matrix : ， in, , , , All are positive numbers. , , , ; Based on the aforementioned symmetric matrix and applying Young's inequality, the following differential inequality is obtained: ， in, , Let be the smallest eigenvalue of the symmetric matrix. , ; Solving the differential inequality yields the convergence error of the Lyapunov function: ， The stability of the system is determined by evaluating the convergence error.

7. A coal mining machine system based on coal and rock identification, characterized in that, The system includes a coal and rock identification part, a control part, a drive part and a mechanical system. The control part includes a control system and a height adjustment tracking controller. The drive part includes a coal mining machine drum height adjustment hydraulic system. The mechanical system includes a drum (11) and a rocker arm (10). The hydraulic system for adjusting the height of the coal mining machine drum includes a control valve and a height adjustment cylinder (9). The control valve is a servo valve or a proportional valve. The control valve controls the position of the piston rod of the height adjustment cylinder (9). The height adjustment cylinder (9) drives the rocker arm (10) to rise and fall through the extension and retraction of the piston rod, thereby adjusting the height of the drum (11). The coal and rock identification part sends the target height of the drum (11) to the control system; the control system calculates the expected displacement of the piston rod according to the target height and inputs the expected displacement to the height adjustment tracking controller; the height adjustment tracking controller sends a control signal to control the hydraulic system for adjusting the height of the coal mining machine drum, performs displacement tracking control on the height adjustment cylinder (9), and then controls the tracking of the height of the drum (11); The height tracking controller is designed using the method described in any one of claims 1-6.

8. The system as described in claim 7, characterized in that, The coal and rock identification section includes a cutting force response detection device, a position detection device, a first data acquisition device, a second data acquisition device, and an automatic coal and rock interface identification system. The driving section also includes a D / A converter and an amplifier. The cutting force response detection device detects the cutting force of the drum (11), the first data acquisition device collects the detection data of the cutting force response detection device and transmits it to the coal-rock interface automatic identification system, the coal-rock interface automatic identification system transmits the coal-rock interface automatic identification result to the control system, the position detection device detects the position information of the drum (11), the second data acquisition device collects the detection data of the position detection device and transmits it to the control system; The height adjustment tracking controller is connected to the D / A converter, the D / A converter is connected to the amplifier, the amplifier is connected to the coal mining machine drum height adjustment hydraulic system, the coal mining machine drum height adjustment hydraulic system is connected to the rocker arm (10), the rocker arm (10) is connected to the drum (11), and the control signal issued by the height adjustment tracking controller is converted by the D / A converter and amplified by the amplifier to drive the action of the coal mining machine drum height adjustment hydraulic system.

9. The system as described in claim 7, characterized in that, The hydraulic system for adjusting the height of the coal mining machine drum also includes an oil tank (1), a filter (2), a motor (3), a hydraulic pump (4), a safety valve (5), a hydraulic lock (8), and a displacement sensor (16). The oil tank (1) is connected to the filter (2), the safety valve (5), and the control valve. The filter (2) and the motor (3) are connected to the hydraulic pump (4). The hydraulic pump (4), the safety valve (5), and the amplifier are connected to the control valve. The control valve is connected to the hydraulic lock (8). The hydraulic lock (8) is connected to the height adjustment cylinder (9). The height adjustment cylinder (9) is connected to the rocker arm (10). The displacement sensor (16) detects the displacement of the piston rod of the height adjustment cylinder (9).

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