Hydraulic servo control system and control method for mining guniting robot

Abstract

The invention discloses a hydraulic servo control system and method for a mining guniting robot. Belongs to the technical field of servo control. Comprising a hydraulic driving unit, a sensing and feedback unit, an electrical control unit, an embedded host and a man-machine interaction unit, wherein the electric control unit adopts a fuzzy PID (Proportion Integration Differentiation) controller for controlling the joint position of the mechanical arm according to the information of the sensing and feedback unit; aiming at linear synchronous control of chassis walking, an anti-integral saturation speed feedforward PI controller is adopted to adjust the opening size and direction of a hydraulic proportional valve in real time, and closed-loop control of the position is achieved.

Description

Technical Field

[0001] This invention relates to the field of servo control technology, and more specifically to a hydraulic servo control system and control method for a mining shotcrete robot. Background Technology

[0002] Mining shotcrete robots are key equipment used in coal mine roadway support operations. Their robotic arms and chassis are mostly driven by hydraulic servo systems. Traditional shotcrete operations rely on manual operation, resulting in low efficiency, inconsistent quality, and high safety risks. Existing hydraulic control systems mostly use conventional PID control, which, while simple in structure, is difficult to adapt to the complex and ever-changing working environment underground. For robotic arm joints, the system exhibits nonlinearity, time-varying parameters, and model uncertainty. Conventional PID controllers tend to have slow response, large overshoot, and weak anti-interference capabilities.

[0003] For tracked chassis, in harsh underground conditions, system restarts or prolonged operation can easily lead to the accumulation of control deviations, causing integral saturation and resulting in problems such as asynchronous movement and sluggish response, requiring frequent manual corrections.

[0004] In recent years, although some studies have attempted to combine fuzzy control with PID to improve adaptive capabilities, there is still a lack of a closed-loop hydraulic servo system that integrates perception, planning and control and can simultaneously solve the problems of nonlinear adaptability and integral saturation, to meet the differentiated control needs of different actuators in hydraulic systems (such as joints and chassis).

[0005] Therefore, how to provide a hydraulic servo control system and control method for a mining shotcrete robot is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a hydraulic servo control system and control method for a mining shotcrete robot, in order to solve the technical problems existing in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A hydraulic servo control system for a mining shotcrete robot includes: The hydraulic drive unit, including a hydraulic pump station, a hydraulic proportional valve group, and actuators, is used to drive the chassis to move and the joints of the robotic arm to move. The sensing and feedback unit includes encoders mounted on the joints of the robotic arm, lidar for environmental perception, and sensors for detecting system status. Electrical control unit, including: An explosion-proof and intrinsically safe programmable control box for mining applications is used to realize data acquisition, motion planning, hydraulic control and status monitoring; An embedded host is used to process lidar point cloud data and generate shotcrete trajectories based on point cloud features; The human-machine interface unit includes a remote control handle terminal that supports switching between manual control and automatic spraying modes; Based on information from the sensing and feedback units, the electrical control unit employs a fuzzy PID controller for joint position control of the robotic arm and an anti-integral saturation speed feedforward PI controller for linear synchronous control of chassis movement. This allows for real-time adjustment of the opening size and direction of the hydraulic proportional valve, achieving closed-loop position control.

[0008] Preferably, the fuzzy PID controller further includes fuzzifying the input and output variables, setting fuzzy subsets and membership functions, and designing fuzzy control rules based on expert experience; and using a weighted average method to defuzzify the parameters to achieve online self-adjustment of the PID parameters.

[0009] Preferably, the anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of the integral term.

[0010] Preferably, the hydraulic proportional valve assembly is an electro-hydraulic proportional directional valve, controlled by a PWM drive module.

[0011] A hydraulic servo control method for a mining shotcrete robot includes the following steps: The tunnel environment is scanned by lidar to obtain point cloud data, and then 3D reconstruction and feature extraction are performed. Based on point cloud features, the shotcrete trajectory is planned to generate the target pose sequence of the robotic arm end effector. Hierarchical control is performed based on the target pose sequence at the end effector of the robotic arm, including: a) A fuzzy PID controller is used for joint position control of the robotic arm; b) For the linear synchronous control of chassis movement, a speed feedforward PI controller with anti-integral saturation is adopted; The control quantities output by the fuzzy PID controller and the speed feedforward PI controller with anti-integral saturation are converted into PWM signals to drive the hydraulic proportional valve group and adjust the motion of the actuator. Position closed-loop control is formed by real-time feedback of position information through encoders.

[0012] Preferably, the fuzzy PID controller further includes fuzzifying the input and output variables, setting fuzzy subsets and membership functions, and designing fuzzy control rules based on expert experience; and using a weighted average method to defuzzify the parameters to achieve online self-adjustment of the PID parameters.

[0013] Preferably, the anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of the integral term.

[0014] Preferably, the hydraulic proportional valve assembly is an electro-hydraulic proportional directional valve, controlled by a PWM drive module.

[0015] As can be seen from the above technical solution, compared with the prior art, this invention discloses a hydraulic servo control system and control method for a mining shotcrete robot. Fuzzy PID and anti-integral saturation speed feedforward PI controllers are used for the robotic arm and chassis movement respectively, specifically solving the nonlinear adaptation problem of the robotic arm and the integral saturation loss-of-synchronization problem of the chassis, achieving optimal overall performance. Simultaneously, fuzzy PID control enables online compensation for the nonlinearity and time-varying nature of the robotic arm's hydraulic system, improving control accuracy and robustness; while speed feedforward PI significantly improves the synchronization and anti-integral saturation capability of the chassis movement. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 A simplified structural diagram of a hydraulic mechanical transmission provided for this invention; Figure 2 The physical model diagram of the valve-controlled asymmetric hydraulic cylinder provided by this invention; Figure 3 This is a schematic diagram of the boom pitch joint drive provided by the present invention; Figure 4 The displacement-joint rotation angle fitting curve provided by the present invention; Figure 5 The block diagram of the open-loop transfer function provided by the present invention; Figure 6 The structural block diagram of the fuzzy PID controller provided by the present invention; Figure 7 Provided by the present invention 、 、 Curves showing the changes in variables e and ec; Figure 8 The structural block diagram of the anti-integral saturation speed feedforward PI controller provided by the present invention; Figure 9 The transfer function block diagram of the anti-integral saturation speed feedforward PI controller provided by the present invention; Figure 10The present invention provides a schematic diagram of a hydraulic servo control system for a mining shotcrete robot. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figure 10 This invention discloses a hydraulic servo control system for a mining shotcrete robot, comprising: The hydraulic drive unit, including a hydraulic pump station, a hydraulic proportional valve group, and actuators, is used to drive the chassis to move and the joints of the robotic arm to move. The sensing and feedback unit includes encoders mounted on the joints of the robotic arm, lidar for environmental perception, and sensors for detecting system status. Electrical control unit, including: An explosion-proof and intrinsically safe programmable control box for mining applications is used to realize data acquisition, motion planning, hydraulic control and status monitoring; An embedded host is used to process lidar point cloud data and generate shotcrete trajectories based on point cloud features; The human-machine interface unit includes a remote control handle terminal that supports switching between manual control and automatic spraying modes; Based on information from the sensing and feedback units, the electrical control unit employs a fuzzy PID controller for joint position control of the robotic arm and an anti-integral saturation speed feedforward PI controller for linear synchronous control of chassis movement. This allows for real-time adjustment of the opening size and direction of the hydraulic proportional valve, achieving closed-loop position control.

[0020] Specifically, the fuzzy PID controller further includes fuzzifying the input and output variables, setting fuzzy subsets and membership functions, and designing fuzzy control rules based on expert experience; it also uses a weighted average method to defuzzify the parameters, thereby achieving online self-adjustment of the PID parameters.

[0021] Specifically, the anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of the integral term.

[0022] Specifically, the hydraulic proportional valve assembly is an electro-hydraulic proportional directional valve, controlled by a PWM drive module.

[0023] Specifically, the robotic arm and chassis employ electro-hydraulic proportional position control. The shotcrete robot is equipped with multiple PWM drive modules, sensor acquisition modules, and wireless communication modules, enabling stepless speed control of the proportional directional valve. It automatically controls the size and direction of the proportional directional valve opening to achieve automatic adjustment of the robotic arm position; and by receiving control signals from the remote controller, it drives the reversing valve to achieve manual adjustment of the robotic arm position.

[0024] In one specific embodiment, the system consists of a hydraulic speed regulation section and a mechanical transmission section, combining the advantages of stepless speed regulation of hydraulic transmission and high-efficiency transmission of mechanical transmission. This enables rapid and smooth starting and braking, achieving stepless speed regulation of the transmission system, and is widely used in engineering vehicle transmission systems. When the engine is running, its output power is divided into two paths by a splitter mechanism: one path is transmitted via a planetary clutch; the other path is transmitted via a variable pump and hydraulic motor speed change mechanism. Finally, the two power paths merge at a converging mechanism and are transmitted to the output shaft.

[0025] like Figure 1 As shown, the mechanical speed regulating mechanism mainly consists of four planetary gear clutches. 3 shift clutches It consists of a flow-dividing mechanism and a flow-merging mechanism. The planetary gear set is a crucial component of the mechanical hydraulic transmission, composed of a planet carrier, a sun gear, and planet gears. Changing the connection method between each unit of the planetary gear set and the external port can achieve different transmission efficiencies. A hybrid hydraulic mechanical transmission using a double planetary gear set achieves the highest efficiency, meeting the requirements of stepless speed regulation and high-efficiency transmission in engineering machinery. Analyzing the motion process of the speed regulating mechanism, the speed ratio of this mechanism can be obtained: ,efficiency In the formula: Let i be the component rotational speed at position i; Engine speed; This represents the characteristic coefficient value of the planet at position j. To determine the working efficiency of the planetary gear set fixed in this transmission.

[0026] A hydraulic speed control mechanism is a hydraulic speed control circuit composed of a variable displacement pump and a fixed displacement motor. For example, in a hydraulic speed control system for engineering vehicles, the controller monitors the vehicle's operating status and converts it into a control signal. This signal is amplified by a proportional valve and then controls the proportional directional valve, which in turn controls the piston movement of a double-piston rod double-acting hydraulic cylinder. This causes a corresponding change in the tilt angle of the variable displacement pump. By adjusting the pump's displacement, the speed of the hydraulic motor is controlled, achieving stepless speed regulation. This speed control circuit boasts strong overall performance. Its output torque remains constant, unaffected by changes in the pump's displacement; it has a wide speed range, with speed changes proportional to the pump's displacement, allowing for stepless speed adjustment by changing the pump's displacement; its output power is proportional to the pump's displacement; and it exhibits good reversing performance, with rapid and smooth commutation. Because the engine's fuel economy and power characteristics are poor during the starting and braking of engineering vehicles, the hydraulic mechanical transmission system is in a pure hydraulic drive state at this time. This fully utilizes the low-speed, high-torque characteristics of the variable pump and motor, allowing the engine to start only after the vehicle speed reaches a certain level, greatly improving the working efficiency of the engineering vehicle. When the engineering vehicle enters a medium-to-high speed motion state, the drive system switches to a hydraulic mechanical transmission mode, stabilizing the engine speed within a certain range, achieving better overall transmission performance, optimal fuel economy, and improved overall transmission efficiency. When the engineering vehicle is under heavy load working conditions such as excavation and climbing, the power required by the vehicle may exceed the engine's working range or high-efficiency zone. At this time, the hydraulic pump acts as an auxiliary power source, working in conjunction with the engine to provide power to the entire vehicle and drive it to complete the predetermined task.

[0027] Compared with traditional hydraulic mechanical transmission, modern hydraulic mechanical transmission has the following advantages: 1) Higher transmission efficiency. Due to the use of low-power hydraulic components, the power density of the system is increased. At the same time, hydraulic systems have low inertia and high sensitivity, making them particularly suitable for high-power transmission. Furthermore, most of the power transmission in a hydraulic mechanical transmission system is through a mechanical circuit, with a small portion transmitted through a hydraulic volumetric speed control circuit. Therefore, the entire system achieves high transmission efficiency, effectively reducing resource waste and maximizing system effectiveness. In particular, the addition of artificial intelligence has effectively improved the control efficiency of the entire hydraulic mechanical transmission power, making it the preferred choice for Chinese construction machinery manufacturers. 2) Higher stability. This is mainly reflected in the following three aspects: First, when construction machinery is working, the heat generated by the transmission system is continuously dissipated to the outside of the system through the circulation of hydraulic oil, avoiding the impact of local overheating on the stability of operation and ensuring the effective and stable operation of the construction machinery; Second, construction vehicles generally operate in harsh field conditions, resulting in poor system stability, while the hydraulic mechanical transmission system has small reversing impact and is easy to achieve frequent reversing, effectively improving the stability of system operation; Third, the hydraulic system adopts multi-layer protection measures and has overload protection function, improving the safety of the system; Fourth, the hydraulic oil, the working medium of the hydraulic system, is a lubricating oil, which can achieve self-lubrication of components, thus extending the service life of the equipment. 3) Automated gear shifting. Traditional mechanical gear shifting is difficult to automate and cannot achieve stepless speed change. Hydraulic mechanical transmission is simple to operate and easy to automate. It can automatically change gears according to the actual needs of the site. Automated gear shifting can ensure that the relevant machinery is always operating in a normal state and, to a certain extent, prevents errors caused by manual operation. In order for an automatic transmission to operate in different gears, the direction of the oil circuit can be switched by using a shift valve, and the oil circuit pressure can be used to enter different control oil circuits to drive the actuators (brakes, clutches, etc.).

[0028] Addressing the two major challenges of structural layout and driving performance in heavy-duty, high-load drive systems, this invention proposes a four-pump, four-motor distributed hydraulic drive system. This system offers a flexible and convenient structural layout, meeting driving performance requirements while providing higher reliability and redundant safety. An AMESim simulation model of the distributed hydraulic drive system was built to analyze the impact of variable motor displacement on the speed regulation performance of the all-terrain vehicle's distributed drive system. Finally, a real-world test on a heavy-duty articulated all-terrain vehicle verified the feasibility of the distributed hydraulic drive system.

[0029] In the development of the heavy-duty tracked all-terrain shotcrete vehicle, a multi-pump, multi-motor distributed drive system was adopted to meet the vehicle's driving power requirements and speed range. This involves using a volumetric speed control system where variable pumps control variable motors for each of the two tracks, with the variable motors fixed next to the drive wheels. This multi-pump, multi-motor distributed drive system not only provides greater power to meet the various operational needs of the heavy-duty articulated all-terrain vehicle, enabling faster forward speeds, stronger climbing ability, and higher operational efficiency, but also allows for flexible control to achieve forward and reverse movements, and provides the vehicle with higher reliability and redundancy safety.

[0030] The power input of the distributed hydraulic drive system comes from the engine. During operation, the engine output torque is transmitted to the input end of the transfer case via the drive shaft. The two output ends of the transfer case drive two variable pumps respectively. Each variable pump is connected in series with a variable motor, transmitting torque through hydrostatic pressure. Adjusting the engine speed and the displacement of the variable pumps can change the flow rate of the hydraulic system. Adjusting the displacement of the variable motor can change the speed and output torque of the hydraulic motor. The variable motor drives the tracks after deceleration and torque increase through wheel-side reducers. The power transmission route diagram is shown in Figure 2. The longitudinal power transmission balance equation of the vehicle is obtained from the vehicle power transmission route as follows:

[0031] In the formula, This is the engine's output torque; Engine speed; For the transfer case output to the first The torque of each hydraulic pump; The speed at which the transfer case outputs to the corresponding hydraulic pump; For hydraulic system pressure; For hydraulic system flow rate; This is the output torque of the hydraulic motor; This refers to the output speed of the hydraulic motor.

[0032] The tilt joint of a robotic arm mainly consists of a mechanical structure, a hydraulic system, and an electrical control system, making it a typical mechatronic system. When constructing the physical model, the control process is abstracted and idealized, with some parts of the model treated linearly, and it is assumed that the hydraulic oil performance parameters do not change over time.

[0033] The boom pitch joint uses an onboard controller to generate a PWM square wave for approximately linear control of the electro-hydraulic proportional directional valve flow. Due to the presence of components such as inductors and capacitors in the analog control circuit, the PWM controller can be considered a lag element. Neglecting higher-order infinitesimal quantities, the transfer function is:

[0034] In the formula This is the input control voltage for the controller; The average output voltage of the PWM converter; For controller system gain; This is the controller delay time.

[0035] Electro-hydraulic proportional directional valves are crucial components of hydraulic servo control systems. Due to the presence of the proportional electromagnet coil, electro-hydraulic proportional directional valves are strictly speaking nonlinear devices. They are typically approximated as proportional elements when nonlinearity is not considered; however, considering their nonlinearity, due to the high natural frequency of the valve control system, they can be treated as second-order elements. This invention models them as second-order oscillatory elements, i.e.:

[0036] In the formula The input control signal is Q(s); the output flow rate change is Q(s). The equivalent undamped natural frequency of the valve; Let be the damping coefficient of the valve, and be a dimensionless constant. This represents the gain of the valve at the steady-state point. To control the gain of converting the voltage signal into a current signal at both ends of the electromagnet.

[0037] The boom tilt joint hydraulic cylinder adopts an asymmetric cylinder design, focusing on the characteristic parameters such as hydraulic oil resistance and viscosity. Considering external disturbances during actual operation, the physical model of the hydraulic cylinder load component can be simplified to a three-position four-way valve, a single-rod piston hydraulic cylinder with arbitrary external load, and an inertial load with elastic and viscous friction, such as... Figure 2 As shown.

[0038] ① Load pressure-flow equation.

[0039] The valve core moves in the forward direction ( Taking >0 as an example, the inflow rate of the hydraulic cylinder is analyzed. Outflow Then the load flow:

[0040] Performing a first-order Taylor expansion, we get:

[0041] In the formula , For flow gain and flow-pressure coefficient; ; (n is the ratio of the area of ​​the rod-side cavity to the area of ​​the rodless cavity); This refers to the valve core displacement; Let the load pressure be denoted as . , , These are the oil source pressure and the oil pressure in the rodless and rod-side chambers of the hydraulic cylinder, respectively. ρ is the flow coefficient; ω is the window area gradient; ρ is the hydraulic oil density.

[0042] ② The flow continuity equation for hydraulic cylinders.

[0043]

[0044] Performing a Laplace transform, we get:

[0045] In the formula The effective working area of ​​the piston is the equivalent flow rate area. Equivalent volume of hydraulic cylinder and These represent the total leakage coefficient and the bulk elastic coefficient.

[0046] ③ Hydraulic cylinder – load dynamics balance equation.

[0047] The forces acting on the hydraulic cylinder under load balance are analyzed, namely:

[0048] Performing a Laplace transform, we get:

[0049] In the formula, m is the load mass; It is the viscous damping coefficient; This refers to the stiffness coefficient of the hydraulic spring. This represents the equivalent external load acting on the piston. The hydraulic cylinder load model is as follows:

[0050] Figure 3 A simplified diagram of the boom pitching motion driven by a hydraulic cylinder. (i=1, 2, 3) represents a rotary joint; the hydraulic cylinder extends and retracts to drive the pitch linkage to rotate around the joint. Link parameter |A |= ,|A |= , | |= , rods | |The zero-position length is , | |and| |Zero-position angle is Ignoring the minute flexible deformation of the robotic arm components, let the joint lengthen by x when the hydraulic cylinder extends. The rotation angle relative to the zero position is θ. A mathematical model is then performed, namely:

[0051] The above equation is a nonlinear equation. Numerical analysis is performed, and the theoretical calculation results are linearly fitted, such as... Figure 4 As shown. Considering structural manufacturing errors and joint assembly clearances, the ratio of rotation angle to hydraulic cylinder extension is subject to random disturbances, namely:

[0052] In the formula θ(s) represents the extension / retraction length of the hydraulic cylinder piston rod relative to the zero position; θ(s) represents the rotation angle of the joint relative to the zero position. To linearly fit the slope of the straight line, the upper arm pitch joint =0.0948° / mm; A is the linear coefficient disturbance amplitude.

[0053] The intelligent shotcrete robot's robotic arm rotation joints utilize high-precision absolute photoelectric encoders, achieving a measurement accuracy of 0.01°. Based on the manufacturer's calibration, the angle sensor can be approximated as a proportional element, i.e.:

[0054] In the formula The photoelectric encoder outputs the measured angle; This represents the feedback amplification factor of the photoelectric encoder. The block diagram of the open-loop transfer function of the boom pitch joint hydraulic control system is shown below. Figure 5 As shown.

[0055] For hydraulic servo control systems with uncertain models, nonlinearity, and complex objects, it is difficult to achieve satisfactory control results using conventional PID controllers. This invention adopts fuzzy PID control, which combines conventional PID control with fuzzy strategies, to design a hydraulic servo system controller.

[0056] The fuzzy PID controller structure used is as follows: Figure 6 As shown, the measured angle value fed back by the sensor is compared with the expected value, and the error signal and error change rate are fuzzified. Then, fuzzy control quantity is obtained through fuzzy rules, inference calculations, etc., and then the precise control quantity is output through defuzzification processing and applied to the controlled system.

[0057] Input / output variable fuzzification and membership function determination: The angular error e and the rate of change of error ec of the boom pitch joint are selected as the input variables of the fuzzy controller, and the output is... , , Considering the universality of the controller's applicability to each joint, e, ec, , , The fuzzy domains are all divided into:

[0058] Its fuzzy subset is: {NB, NM, NS, ZO, PS, PM, PM}; For different control objectives of the controller, appropriate quantization and scaling factors are selected to map the input and output quantities to the universe of discourse of the fuzzy set. The two fuzzy subsets (NB and PB) adopt sigmoid function curves, and the middle fuzzy subset adopts a triangular distribution.

[0059] Fuzzy control rule design: The fuzzy control rules are the core of the fuzzy control algorithm. Based on practical experience, the following conclusions are drawn. , , Fuzzy control rules.

[0060] Parameter deblurring: The result of fuzzy inference is a fuzzy set, which cannot be directly used to control the controlled object and needs to be defuzzified. Considering both computational complexity and accuracy, this invention uses a weighted average method for defuzzification, as shown in the following figure. Figure 7 As shown.

[0061] Due to the limitations of the working conditions underground, and the possibility of system restarts during the actual control of the hydraulically driven robotic arm, the control system may experience prolonged deviations. This can lead to integral accumulation in the controller, resulting in problems such as sluggish response and linear asynchrony. Continuous corrections to the robotic arm and tracked chassis are necessary.

[0062] See Figure 8-9 To address the aforementioned problems, this invention provides a speed feedforward PI controller that resists integral saturation. The controller calculates the speed feedforward term from the current error and speed information, and adjusts the flow rate of the corresponding valve opening of the motor, thereby offsetting the integral effect caused by the accumulation of deviation.

[0063] On the other hand, the present invention also provides a hydraulic servo control method for a mining shotcrete robot, comprising the following steps: The tunnel environment is scanned by lidar to obtain point cloud data, and then 3D reconstruction and feature extraction are performed. Based on point cloud features, the shotcrete trajectory is planned to generate the target pose sequence of the robotic arm end effector. Hierarchical control is performed based on the target pose sequence at the end effector of the robotic arm, including: a) A fuzzy PID controller is used for joint position control of the robotic arm; b) For the linear synchronous control of chassis movement, a speed feedforward PI controller with anti-integral saturation is adopted; The control quantities output by the fuzzy PID controller and the speed feedforward PI controller with anti-integral saturation are converted into PWM signals to drive the hydraulic proportional valve group and adjust the motion of the actuator. Position closed-loop control is formed by real-time feedback of position information through encoders.

[0064] Specifically, the fuzzy PID controller also includes fuzzification of input and output variables, setting fuzzy subsets and membership functions, and designing fuzzy control rules based on expert experience; it also uses a weighted average method to defuzzify parameters and realize online self-adjustment of PID parameters.

[0065] Specifically, the anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of the integral term.

[0066] Specifically, the hydraulic proportional valve assembly is an electro-hydraulic proportional directional valve, controlled by a PWM drive module.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic servo control system for a mine guniting robot, characterized in that, Comprise: Hydraulic drive unit, including hydraulic pump station, hydraulic proportional valve group and actuator, for driving chassis walking and each joint movement of mechanical arm; Sensing and feedback unit, including encoder installed on each joint of mechanical arm, laser radar for environment perception, and sensor for detecting system state; Electrical control unit, comprising: Mining explosion-proof and intrinsically safe programmable control box for realizing data acquisition, motion planning, hydraulic control and state monitoring; Embedded host for processing laser radar point cloud data and generating shotcrete trajectory based on point cloud features; Man-machine interaction unit, including remote control handle terminal, supporting manual control and automatic shotcrete mode switching; The electrical control unit adopts fuzzy PID controller for mechanical arm joint position control according to the information of the sensing and feedback unit; adopts anti-integral saturation speed feedforward PI controller for straight line synchronous control of chassis walking, to adjust the opening size and direction of the hydraulic proportional valve in real time, and realize closed loop control of position.

2. The hydraulic servo control system of the mine guniting robot according to claim 1, characterized in that, The fuzzy PID controller further comprises fuzzy processing of input and output variables, setting of fuzzy subsets and membership functions, and design of fuzzy control rules based on expert experience; weighted average method is used for parameter defuzzification to realize online self-adjustment of PID parameters.

3. The hydraulic servo control system of the mine guniting robot according to claim 1, characterized in that, The anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of integral term.

4. The hydraulic servo control system of the mine guniting robot according to claim 1, characterized in that, The hydraulic proportional valve group is an electro-hydraulic proportional directional valve controlled by PWM driving module.

5. A hydraulic servo control method for a mine guniting robot, characterized by, Comprise the following steps: Scan the tunnel environment by laser radar, obtain point cloud data, and perform three-dimensional reconstruction and feature extraction; Based on point cloud features, plan shotcrete trajectory and generate target pose sequence of mechanical arm end; Based on the target pose sequence of the mechanical arm end, execute hierarchical control, including: a) For mechanical arm joint position control, adopt fuzzy PID controller; b) For straight line synchronous control of chassis walking, adopt anti-integral saturation speed feedforward PI controller; Convert the control amount output by the fuzzy PID controller and the anti-integral saturation speed feedforward PI controller into PWM signal to drive the hydraulic proportional valve group and adjust the movement of the actuator; Real-time feedback of position information by encoder constitutes position closed loop control.

6. The hydraulic servo control method for a mine guniting robot according to claim 5, characterized in that, The fuzzy PID controller further comprises fuzzy processing of input and output variables, setting of fuzzy subsets and membership functions, and design of fuzzy control rules based on expert experience; weighted average method is used for parameter defuzzification to realize online self-adjustment of PID parameters.

7. The hydraulic servo control method for a mine guniting robot according to claim 5, characterized in that, The anti-integral saturation speed feedforward PI controller includes a speed feedforward term and limits the accumulation of integral term.

8. The hydraulic servo control method for a mine guniting robot according to claim 5, characterized in that, The hydraulic proportional valve group is an electro-hydraulic proportional directional valve controlled by PWM driving module.

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