Force / Position Disturbance Rejection Control Method for the Boom Electro-Hydraulic Drive System of a Tunnel Equipment

Abstract

The present invention discloses a force / position disturbance rejection control method for a boom electro-hydraulic drive system of tunnel equipment. The method includes: establishing a mathematical model of a valve-controlled asymmetric cylinder for the boom electro-hydraulic drive system of tunnel operation equipment; designing a nonlinear cascade controller with a position outer loop and a force inner loop; on this basis, establishing mathematical models of disturbance observers for the inner and outer loops respectively to estimate and compensate in real time the disturbance factors such as unmodeled dynamics, parameter uncertainties and external loads existing in the models; proving the stability of the closed-loop system based on the Lyapunov stability theory; verifying the effectiveness of the controller by comparing simulation and experimental results; the present invention can solve the problems of low control accuracy and poor disturbance rejection performance of the boom of tunnel operation equipment.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic boom control of tunnel operation equipment, and particularly relates to a force / position disturbance rejection control method for an electro-hydraulic drive system of a tunnel equipment boom. Background Technique

[0002] Tunnel excavation is a time-consuming, difficult and extremely challenging construction operation. With the development of the mechanization, automation and intelligence of tunnel drilling and blasting operation equipment, the requirements for operation accuracy are also getting higher and higher. At present, tunnel drilling and blasting operation equipment represented by rock drilling jumbo, wet shotcreting jumbo, etc. mostly adopts large-scale hydraulic boom structures, and the control method of its electro-hydraulic drive system is often PID control. However, the complex and changeable underground environment makes the hydraulic parameters (such as oil elastic modulus) of tunnel operation equipment have large parameter uncertainties. At the same time, various geological conditions (rock burst, large deformation of soft rock, etc.) make the tunnel operation equipment subject to large time-varying external load disturbances when performing rock layer contact operations. These factors pose great challenges to the robustness of the control algorithm and seriously affect the operation accuracy of tunnel drilling and blasting equipment. Summary of the Invention

[0003] Aiming at the above technical problems, the present invention provides a force / position disturbance rejection control method for an electro-hydraulic drive system of a tunnel equipment boom.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] A force / position disturbance rejection control method for an electro-hydraulic drive system of a tunnel equipment boom, the method includes the following steps:

[0006] S100: Obtain the parameter information of the valve-controlled asymmetric cylinder system of the boom electro-hydraulic drive system, and establish a mathematical model of the valve-controlled asymmetric cylinder of the boom electro-hydraulic drive system according to the parameter information, including the flow continuity equation, valve port flow equation and force balance equation of the valve-controlled asymmetric cylinder;

[0007] S200: Design an outer-loop nonlinear disturbance observer to dynamically estimate the outer-loop lumped disturbance in the force balance equation of the valve-controlled asymmetric cylinder, design an outer-loop position tracking controller of the valve-controlled asymmetric cylinder based on the disturbance observer, and combine the current position, desired position and the expression of the outer-loop lumped disturbance estimation to obtain the virtual control input expression of the outer-loop position tracking, and adjust the outer-loop feedback gain parameter to make the outer-loop position tracking meet the preset outer-loop control performance index;

[0008] S300: Based on the force balance equation of the valve-controlled asymmetric cylinder, the virtual control input expression, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation, obtain the differential expression of the inner-loop force tracking error function. Design an inner-loop nonlinear disturbance observer to dynamically estimate the inner-loop lumped disturbance in the differential expression of the inner-loop force tracking error function. Design an inner-loop force tracking controller for the valve-controlled asymmetric cylinder based on the disturbance observer. Combine the differential expression of the force tracking error function and the expression of the inner-loop lumped disturbance estimation to obtain the inner-loop force tracking control input. Adjust the inner-loop feedback gain parameter to make the inner-loop force tracking meet the preset inner-loop control performance index;

[0009] S400: The sensor acquires the output parameters of the boom valve-controlled asymmetric cylinder. Among them, the output parameters include the position and the pressure of the asymmetric cylinder. Feed back the difference between the current position and the current position to the outer-loop position tracking controller and the inner-loop force tracking controller. Feed back the pressure of the asymmetric cylinder to the inner-loop force tracking controller, and return to S200 to continue adjusting the outer-loop feedback gain parameter and the inner-loop feedback gain parameter, so that the outer-loop position tracking and the inner-loop force tracking meet the preset corresponding control performance indexes.

[0010] Preferably, in S100, establish the flow continuity equation of the valve-controlled asymmetric cylinder according to the parameter information. Specifically:

[0011]

[0012] where, V1 = V 10 + A1x and V2 = V 20 - A2x are the effective volumes of the rodless chamber and the rod chamber of the hydraulic cylinder respectively. V 10 and V 20 are the initial volumes of the rodless chamber, the rod chamber and the connected pipelines respectively. x is the equivalent load displacement. β e is the effective volume elastic modulus. P1 and P2 are the pressures of the rodless chamber and the rod chamber of the hydraulic cylinder respectively. A1 and A2 are the effective working areas of the rodless chamber and the rod chamber of the hydraulic cylinder respectively. Q1 and Q2 are the valve port flows of the rodless chamber and the rod chamber of the hydraulic cylinder respectively. f1 and f2 represent the lumped disturbances of the rodless chamber and the rod chamber of the hydraulic cylinder respectively.

[0013] Preferably, in S100, establish the valve port flow equation of the valve-controlled asymmetric cylinder according to the parameter information. Specifically:

[0014]

[0015] where, c1, c2, c3, c4 are the gain coefficients of the electro-hydraulic proportional valve respectively, which are determined by the shape and size of the valve orifice. P S is the oil supply outlet pressure, and P T is the oil return port pressure;

[0016] According to Newton's second law, the force balance equation of the valve-controlled asymmetric cylinder can be expressed as:

[0017]

[0018] where x is the equivalent load displacement, is the equivalent load velocity, is the equivalent load acceleration, m is the equivalent mass of the piston rod and the load, b represents the viscous friction coefficient, F is the driving force exerted on the system by the valve-controlled hydraulic cylinder, and f l represents the lumped disturbance term of the rodless chamber of the hydraulic cylinder in the force balance equation.

[0019] Preferably, in S200, an outer-loop nonlinear disturbance observer is designed to dynamically estimate the lumped disturbance in the force balance equation of the valve-controlled asymmetric cylinder, including:

[0020] S210: Obtain the state-space expression based on the force balance equation of the valve-controlled asymmetric cylinder;

[0021] S220: Design an outer-loop nonlinear disturbance observer according to the lumped disturbance in the state-space expression to dynamically estimate the lumped disturbance in the outer loop.

[0022] Preferably, S210 is specifically:

[0023] Define the state variables [x1, x2] T = [x, v] T , and the state-space expression can be sorted out according to the hydraulic cylinder force balance equation as:

[0024]

[0025] where x1 is the equivalent load displacement and x2 is the equivalent load velocity;

[0026] Assume that the variation rate l of the lumped disturbance f in the outer loop is bounded, that is For the lumped disturbance f in the outer loop l , S220 is specifically:

[0027]

[0028] where Z is the auxiliary design variable, k1 is the observer gain to be designed, is the estimated value of the lumped disturbance f in the outer loop l , and the estimation error is defined as If the lumped disturbance f in the outer loop l satisfies the above assumptions, then by determining the specific value of the gain k1, the outer-loop nonlinear disturbance observer can ensure the estimation error Uniformly bounded stability.

[0029] Preferably, in S200, a valve-controlled asymmetric cylinder outer-loop position tracking controller based on a disturbance observer is designed, and a virtual control input expression for outer-loop position tracking is obtained by combining the current position, the desired position, and the expression of the outer-loop lumped disturbance estimation, including:

[0030] S230: Design a valve-controlled asymmetric cylinder outer-loop position tracking controller based on a disturbance observer, and define a position error function according to the current position and the desired position;

[0031] S240: Differentiate the position error function to obtain a differential expression of the position error function;

[0032] S250: Obtain a virtual control input expression for outer-loop position tracking according to the expression of the outer-loop lumped disturbance estimation and the differential expression of the position error function.

[0033] Preferably, S230 is specifically:

[0034]

[0035] where x 1d , x1 are respectively the desired position of the equivalent load and the actual position of the equivalent load, e1 represents the output position tracking error, and λ>0 is the feedback gain;

[0036] S240 is specifically:

[0037]

[0038] S250 is specifically:

[0039]

[0040] where F d is the virtual control input for outer-loop position tracking, k p , k v are respectively the outer-loop feedback gain parameters;

[0041] Preferably, S300 includes:

[0042] S310: Define an inner-loop force tracking error function based on the virtual control input expression for outer-loop position tracking;

[0043] S320: Differentiate the inner-loop force tracking error function, and combine the state space parameters of the force balance equation, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation to obtain a differential expression of the inner-loop force tracking error function;

[0044] S330: Design an inner-loop nonlinear disturbance observer based on the lumped disturbance in the differential expression of the inner-loop force tracking error function to dynamically estimate the inner-loop lumped disturbance;

[0045] S340: Design a valve-controlled asymmetric cylinder inner-loop force tracking controller based on the disturbance observer according to the differential expression of the inner-loop force tracking error function and the estimated expression of the inner-loop lumped disturbance to obtain the inner-loop force tracking control input;

[0046] S350: By adjusting the inner-loop feedback gain parameter, make the inner-loop force tracking meet the preset inner-loop control performance index.

[0047] Preferably, S310 is specifically:

[0048] e3 = F d -F(9)

[0049] where e3 is the force tracking error;

[0050] S320 is specifically:

[0051]

[0052] where

[0053]

[0054] Preferably, assume that the change rates of f1 and f2 of the lumped disturbance in the flow continuity equation of the valve-controlled asymmetric cylinder are bounded, that is holds, then the change rate of the inner-loop lumped disturbance d l composed of f1 and f2 is also bounded;

[0055] S330 is specifically:

[0056]

[0057] where Z is an auxiliary design variable, k2 is the observer gain to be designed, is the estimated value of the inner-loop lumped disturbance d l The estimation error is defined as If the inner-loop lumped disturbance d l meets the above assumptions, then by determining the specific value of the gain k2, the inner-loop disturbance observer can ensure that the estimation error is uniformly bounded and stable;

[0058] S340 is specifically:

[0059]

[0060] where u is the inner-loop force tracking control input, k fis the inner loop feedback gain parameter.

[0061] The above force / position disturbance rejection control method for the boom electro-hydraulic drive system of a tunneling equipment establishes a mathematical model of a valve-controlled asymmetric cylinder for the boom electro-hydraulic drive system of tunneling operation equipment; designs a non-linear cascade controller including a position outer loop and a force inner loop; on this basis, disturbance observer mathematical models are established for the outer and inner loops respectively to estimate and compensate the lumped disturbances in the outer loop and the lumped disturbances in the inner loop in real time; overcome the influence of the lumped disturbance factors existing in the model, improve the motion control accuracy of the hydraulic boom of the tunneling drill and blast method operation equipment, and can also realize the position disturbance rejection and force disturbance rejection control of the hydraulic boom system respectively according to the actual engineering requirements, meet the signal tracking control under different operation conditions, and solve the problems of low control accuracy and poor disturbance rejection of the boom control of tunneling operation equipment. Description of the Drawings

[0062] Figure 1 is the flow chart of the force / position disturbance rejection control method for the boom electro-hydraulic drive system of a tunneling equipment in an embodiment of the present invention;

[0063] Figure 2 is the block diagram of the force / position disturbance rejection control system of the boom electro-hydraulic drive system of tunneling operation equipment established in an embodiment of the present invention;

[0064] Figure 3 is the typical schematic diagram of the hydraulic boom valve-controlled asymmetric cylinder system in an embodiment of the present invention;

[0065] Figure 4 is the expected tracking trajectory of the simulation system in an embodiment of the present invention;

[0066] Figure 5 is the curve of position disturbance estimation and force disturbance estimation of the simulation system in an embodiment of the present invention;

[0067] Figure 6 is the comparison diagram of the position tracking and force tracking effects and tracking errors of the simulation system in an embodiment of the present invention;

[0068] Figure 7 is the comparison diagram of the tracking errors between the present invention and the PID control of the experimental system in an embodiment of the present invention. Detailed Embodiments

[0069] In order to enable those skilled in the art of the present technology to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0070] In one embodiment, as Figure 1 and 2 shown, a force / position disturbance rejection control method for the boom electro-hydraulic drive system of a tunneling equipment includes the following steps:

[0071] S100: Obtain the parameter information of the valve-controlled asymmetric cylinder system of the boom electro-hydraulic drive system, and establish the mathematical model of the boom electro-hydraulic drive system's valve-controlled asymmetric cylinder according to the parameter information, including the flow continuity equation, valve port flow equation, and force balance equation of the valve-controlled asymmetric cylinder.

[0072] Specifically, for the hydraulic boom structure and electro-hydraulic drive form of the tunnel drilling and blasting operation equipment, considering the disturbance factors including uncertain oil elastic modulus parameter, time-varying external load disturbance, unmodeled friction force, etc., establish the mathematical model of the hydraulic boom valve-controlled asymmetric cylinder system.

[0073] In one embodiment, the flow continuity equation of the valve-controlled asymmetric cylinder is established according to the parameter information in S100, specifically as follows:

[0074]

[0075] Among them, V1 = V 10 + A1x and V2 = V 20 - A2x are the effective volumes of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, V 10 and V 20 are the initial volumes of the rodless chamber, rod chamber and the connected pipeline respectively, x is the equivalent load displacement, β e is the effective volume elastic modulus, P1 and P2 are the pressures of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, A1 and A2 are the effective working areas of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, Q1 and Q2 are the valve port flows of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, and f1 and f2 respectively represent the lumped disturbances of the rodless chamber and the rod chamber of the hydraulic cylinder.

[0076] Specifically, as Figure 3 shown in the schematic diagram of the typical structure of the valve-controlled asymmetric cylinder system.

[0077] In one embodiment, the valve port flow equation of the valve-controlled asymmetric cylinder is established according to the parameter information in S100, specifically as follows:

[0078]

[0079] Among them, c1, c2, c3, c4 are the gain coefficients of the electro-hydraulic proportional valve respectively, which are determined by the shape and size of the valve hole, P S is the oil supply outlet pressure, P T is the oil return port pressure;

[0080] According to Newton's second law, the force balance equation of the valve-controlled asymmetric cylinder can be expressed as:

[0081]

[0082] Among them, x is the equivalent load displacement, is the equivalent load speed, is the equivalent load acceleration, m is the equivalent mass of the piston rod and the load, b represents the viscous friction coefficient, F is the driving force exerted on the system by the valve-controlled hydraulic cylinder, f l represents the lumped disturbance term in the rodless chamber of the hydraulic cylinder in the force balance equation.

[0083] S200: Design an outer-loop nonlinear disturbance observer to dynamically estimate the lumped disturbance in the outer loop of the force balance equation of the valve-controlled asymmetric cylinder. Design an outer-loop position tracking controller for the valve-controlled asymmetric cylinder based on the disturbance observer. Combine the current position, the desired position, and the expression of the estimated lumped disturbance in the outer loop to obtain the expression of the virtual control input for outer-loop position tracking. Adjust the outer-loop feedback gain parameter to make the outer-loop position tracking meet the preset outer-loop control performance index.

[0084] Specifically, the virtual control input for outer-loop position tracking is the desired force for inner-loop force tracking.

[0085] In one embodiment, in S200, designing an outer-loop nonlinear disturbance observer to dynamically estimate the lumped disturbance in the outer loop of the force balance equation of the valve-controlled asymmetric cylinder includes:

[0086] S210: Deform the force balance equation of the valve-controlled asymmetric cylinder to obtain the state-space expression of the equation;

[0087] S220: Design an outer-loop nonlinear disturbance observer according to the lumped disturbance in the state-space expression to dynamically estimate the lumped disturbance in the outer loop.

[0088] In one embodiment, S210 is specifically:

[0089] Define the state variables [x1, x2] T =[x, v] T , and according to the force balance equation of the hydraulic cylinder, the state-space expression can be sorted out as:

[0090]

[0091] where x1 is the equivalent load displacement in the rodless chamber, and x2 is the equivalent load speed;

[0092] Assume that the change rate l of the lumped disturbance f in the outer loop is bounded, that is For the lumped disturbance f in the outer loop l , S220 is specifically:

[0093]

[0094] where Z is the auxiliary design variable, and k1 is the observer gain to be designed, is the estimated value of the outer - loop lumped disturbance \(f\) l , and the estimation error is defined as If the outer - loop lumped disturbance \(f\) l satisfies the above assumptions, then by determining the specific value of the gain \(k_1\), the outer - loop nonlinear disturbance observer can ensure that the estimation error is uniformly bounded and stable.

[0095] Proof: Differentiating the estimation error yields

[0096]

[0097] By choosing an appropriate gain \(k_1\), the outer - loop disturbance observer can ensure that the estimation error is uniformly bounded and stable, and when the rate of change of the outer - loop lumped disturbance \(f\) l tends to zero, the estimation error is uniformly asymptotically stable. Q.E.D.

[0098] In one embodiment, in S200, a valve - controlled asymmetric cylinder outer - loop position tracking controller based on a disturbance observer is designed. Combining the current position, the desired position, and the expression of the outer - loop lumped disturbance estimation, the expression of the virtual control input for outer - loop position tracking is obtained, including:

[0099] S230: Design a valve - controlled asymmetric cylinder outer - loop position tracking controller based on a disturbance observer, and define a position error function according to the current position and the desired position;

[0100] S240: Differentiate the position error function to obtain the differential expression of the position error function;

[0101] S250: Obtain the expression of the virtual control input for outer - loop position tracking according to the expression of the outer - loop lumped disturbance estimation and the differential expression of the position error function.

[0102] In one embodiment, S230 is specifically:

[0103]

[0104] where \(x\) 1d , \(x_1\) are the desired position of the equivalent load and the actual position of the equivalent load respectively, \(e_1\) represents the output position tracking error, and \(\lambda>0\) is the feedback gain.

[0105] Specifically, the design goal of the outer - loop controller should make \(e_2\) as small as possible or tend to zero. At this time, the position tracking error \(e_1\) will also be very small or tend to zero.

[0106] S240 is specifically:

[0107]

[0108] Specifically, the desired driving force F d can be regarded as a virtual control input, that is, a reasonable desired driving force input is designed to make the position tracking error e1 as small as possible or tend to zero.

[0109] Specifically, S250 is:

[0110]

[0111] where F d is the virtual control input for outer-loop position tracking, and k p , k v are the outer-loop gain parameters respectively.

[0112] Specifically, finally, by adjusting the feedback gain parameters k1, k p , k v the virtual control input quantity for outer-loop position tracking, that is, the desired force for inner-loop force tracking, is obtained, so that the outer-loop position tracking meets the control performance index.

[0113] Select the following Lyapunov function to verify the stability of the outer-loop position tracking control system:

[0114]

[0115] Differentiating the above formula and combining with the position error function (6) and the differential expression (7) of the position error function, we get:

[0116]

[0117] Select the virtual control input F d as:

[0118]

[0119] where k v =m(λ + w1)>0, k p =m(λw1 + 1)>0. Substituting the formula for differentiating the estimation error and Equation (17) into Equation (16), we get:

[0120]

[0121] where Define the total error quantity Then, from Equation (18), it can be obtained that after a certain finite time t1>0, the total error quantity E1 will enter and remain within a certain spherical boundary B r and And when the outer-loop lumped disturbance f l change rate As it approaches zero, the total error amount E1 will asymptotically stabilize to zero, so the system is stable.

[0122] S300: Based on the force balance equation of the valve-controlled asymmetric cylinder, the virtual control input expression, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation, obtain the differential expression of the inner-loop force tracking error function. Design an inner-loop nonlinear disturbance observer to dynamically estimate the inner-loop lumped disturbance in the differential expression of the inner-loop force tracking error function. Design a valve-controlled asymmetric cylinder inner-loop force tracking controller based on the disturbance observer. Combine the differential expression of the force tracking error function and the expression of the inner-loop lumped disturbance estimation to obtain the inner-loop force tracking control input. Adjust the inner-loop feedback gain parameter to make the inner-loop force tracking meet the preset inner-loop control performance index.

[0123] Specifically, the inner-loop force tracking control input is the actual spool input.

[0124] In one embodiment, S300 includes:

[0125] S310: Define the inner-loop force tracking error function based on the virtual control input expression of the outer-loop position tracking;

[0126] S320: Differentiate the inner-loop force tracking error function, and combine the state space parameters of the force balance equation, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation to obtain the differential expression of the inner-loop force tracking error function;

[0127] S330: Design an inner-loop nonlinear disturbance observer to dynamically estimate the inner-loop lumped disturbance according to the inner-loop lumped disturbance in the differential expression of the inner-loop force tracking error function;

[0128] S340: Design a valve-controlled asymmetric cylinder inner-loop force tracking controller based on the disturbance observer according to the differential expression of the inner-loop force tracking error function and the inner-loop lumped disturbance estimation expression, and obtain the inner-loop force tracking control input;

[0129] S350: Adjust the inner-loop feedback gain parameter to make the inner-loop force tracking meet the preset inner-loop control performance index.

[0130] In one embodiment, S310 is specifically:

[0131] e3 = F d -F(9)

[0132] where e3 is the force tracking error;

[0133] S320 is specifically:

[0134]

[0135] where

[0136]

[0137] In one embodiment, assuming that the rates of change of f1 and f2 of the lumped disturbance in the flow continuity equation of the valve-controlled asymmetric cylinder are bounded, that is holds, then the rate of change of the lumped disturbance d l composed of f1 and f2 is also bounded;

[0138] S330 is specifically:

[0139]

[0140] where Z is an auxiliary design variable and k2 is the observer gain to be designed, is the estimated value of the lumped disturbance d l of the inner loop, and the estimation error is defined as If the lumped disturbance d l of the inner loop satisfies the above assumptions, then by determining the specific value of the gain k2, the inner-loop disturbance observer can ensure that the estimation error is uniformly bounded and stable.

[0141] Specifically, it is proved that: differentiating the estimation error gives:

[0142]

[0143] By selecting an appropriate gain k2, the disturbance observer (12) can ensure that the estimation error is uniformly bounded and stable, and when the rate of change of d l of the lumped disturbance of the inner loop tends to zero, the estimation error is uniformly asymptotically stable. Q.E.D.

[0144] S340 is specifically:

[0145]

[0146] where u is the inner-loop force tracking control input and k f is the inner-loop gain parameter.

[0147] Specifically, by adjusting the feedback gain parameters k2 and k f , the inner-loop force tracking satisfies the control performance index.

[0148] Select the following Lyapunov function to verify the stability of the inner-loop force tracking control system:

[0149]

[0150] Differentiating Equation (20) and combining it with Equation (10) gives:

[0151]

[0152] Substitute the control input u in Equation (13) into Equation (21):

[0153]

[0154] where Define the total error quantity Then, from Equation (22), it can be obtained that after a certain finite time t1 > 0, the total error quantity E2 will enter and remain within a certain spherical boundary B r and and when the change rate l of the lumped disturbance d of the inner loop approaches zero, the total error quantity E2 will asymptotically stabilize to zero, so the system is stable.

[0155] S400: The sensor acquires the output parameters of the boom valve-controlled asymmetric cylinder. Among them, the output parameters include the position and the pressure of the asymmetric cylinder. The difference between the current position and the current position is fed back to the outer-loop position tracking controller and the inner-loop force tracking controller, and the pressure of the asymmetric cylinder is fed back to the inner-loop force tracking controller, and then return to S200 to continue adjusting the outer-loop feedback gain parameter and the inner-loop feedback gain parameter, so that the outer-loop position tracking and the inner-loop force tracking meet the preset corresponding control performance indicators.

[0156] Specifically, the sensor measures the position and pressure states of the valve-controlled asymmetric cylinder system, obtains the difference of the position according to the position, and transmits the corresponding states to the corresponding nonlinear cascade controller and disturbance observer to realize the estimation of the lumped disturbance in the inner and outer loops and the feedback of the tracking error.

[0157] The above method is aimed at the hydraulic boom structure and the electro-hydraulic drive form of the tunnel drill and blast method operation equipment, considering disturbance factors including uncertain oil elastic modulus parameters, time-varying external load disturbances, unmodeled friction forces, etc., and establishing a mathematical model of the hydraulic boom valve-controlled asymmetric cylinder system; sensors are installed in the electro-hydraulic drive system, and the sensors measure the position, speed and pressure states of the valve-controlled asymmetric cylinder system and transmit the corresponding states to the corresponding nonlinear cascade controller and disturbance observer to realize the estimation of the lumped disturbance in the inner and outer loops and the feedback of the tracking error. Finally, the stability of the control system is guaranteed by the Lyapunov stability theory, the hydraulic boom force / position tracking error is reduced, and the control performance is improved, so as to solve the problems of low boom control accuracy and poor anti-disturbance ability of the existing tunnel drill and blast method operation equipment.

[0158] Compared with the prior art, the present invention has the following beneficial effects:

[0159] 1. Based on the established valve-controlled asymmetric cylinder model of the boom electro-hydraulic drive system for tunnel equipment, the present invention designs a non-linear cascade controller with a double disturbance observer for the position outer loop and the force inner loop, overcoming the influence of unmodeled dynamics, parameter uncertainties, external load and other disturbance factors in the model, and improving the motion control accuracy of the hydraulic boom of the tunnel drill and blast operation equipment. 2. The non-linear cascade controller established by the present invention can respectively achieve position disturbance rejection and force disturbance rejection control of the hydraulic boom system according to the actual engineering requirements, and meet the signal tracking control under different operating conditions.

[0160] The control effect of the control method of the present invention is verified below by combining specific Simulink simulations and on-site experiments. Figure 4 is the command signal for position control.

[0161] Table 1 shows the parameters of the simulation model, and the parameters are obtained by experimental identification.

[0162]

[0163] Select the controller parameter k p = 240, k f = 200, the disturbance observer gains k1 = 2000, k2 = 400.

[0164] The position command signal y = 0.5 + 0.1sin(0.2πt) (m).

[0165] The disturbance factors consider the parameter uncertainties of the viscous friction coefficient b and the oil elastic modulus β, as well as the time-varying external load disturbance F l , where the uncertainties of the viscous friction coefficient b and the oil elastic modulus β are 10% of the nominal values, that is, Δb = 6.25e4 (N / (m / s)), Δβ = 1e8 (Pa). Select the time-varying external load disturbance F l = 10000sin(πt) (N), and when the simulation time reaches 40 seconds, the time-varying external load disturbance is added.

[0166] In the on-site experiment, the commonly used PID control in engineering is taken as a comparison. The system parameters are the same as those of the simulation model and are obtained through parameter identification experiments. The gains of the PID are tuned through experiments. Select k p = 350, k i = 1.5, k d = 1.5. The position command signal is selected as y = 0.5 + 0.1sin(0.1πt) (m), the sampling frequency is 1KHz, and the controller output period is 30ms.

[0167] Figures 5a - 5b is the disturbance estimation result of the disturbance observer established by the present invention, where Figure 5a is the lumped disturbance f of the position outer loopl Comparison of the estimation results. In the figure, the solid line represents the magnitude of the actual lumped disturbance value caused by the uncertainty Δb of the viscous friction coefficient and the time-varying external load disturbance F l The dotted line represents the estimated value of the disturbance value by the outer-loop disturbance observer. Figure 5b The lumped disturbance of the force inner loop is d l Comparison of the estimation curves of. In the figure, the solid line represents the magnitude of the actual lumped disturbance value caused by the uncertainty Δβ of the oil elastic modulus. The dotted line represents the estimated value of the disturbance value by the inner-loop disturbance observer.

[0168] Figures 6a - 6d are the outer-loop position and inner-loop force tracking signals and tracking error curves.

[0169] Figure 7 is the comparison diagram of the on-site experimental position tracking control error between the present invention and the common PID algorithm.

[0170] As can be seen from the above figure, in the simulation example, in the presence of factors such as parameter uncertainties (viscous friction coefficient, oil elastic modulus) and external load disturbances, the force / position disturbance rejection control method proposed by the present invention can accurately estimate the lumped disturbance caused by the above factors and achieve precise tracking of the target position and force.

[0171] In the on-site experiment, compared with the commonly used PID in engineering, the force / position disturbance rejection control method proposed by the present invention has a smaller tracking error and a shorter transient response time. It can effectively improve the control accuracy and disturbance rejection ability of the boom of the tunnel operation equipment.

[0172] The above has introduced in detail a force / position disturbance rejection control method for an electro-hydraulic drive system of a tunnel equipment boom provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A force / position disturbance rejection control method for the electro-hydraulic drive system of the boom of tunnel equipment, characterized in that, The method includes the following steps: S100: Obtain the parameter information of the valve-controlled asymmetric cylinder system of the boom electro-hydraulic drive system, and establish a mathematical model of the valve-controlled asymmetric cylinder of the boom electro-hydraulic drive system according to the parameter information, including the flow continuity equation, the valve port flow equation, and the force balance equation of the valve-controlled asymmetric cylinder; S200: Design an outer-loop nonlinear disturbance observer to dynamically estimate the outer-loop lumped disturbance in the force balance equation of the valve-controlled asymmetric cylinder, design an outer-loop position tracking controller of the valve-controlled asymmetric cylinder based on the disturbance observer, combine the current position, the desired position, and the expression of the outer-loop lumped disturbance estimation to obtain an expression of the virtual control input for outer-loop position tracking, and adjust the outer-loop feedback gain parameter to make the outer-loop position tracking meet the preset outer-loop control performance index; S300: Based on the force balance equation of the valve-controlled asymmetric cylinder, the virtual control input expression, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation, obtain a differential expression of the inner-loop force tracking error function, design an inner-loop nonlinear disturbance observer to dynamically estimate the inner-loop lumped disturbance in the differential expression of the inner-loop force tracking error function, design an inner-loop force tracking controller of the valve-controlled asymmetric cylinder based on the disturbance observer, combine the differential expression of the force tracking error function and the expression of the inner-loop lumped disturbance estimation to obtain the inner-loop force tracking control input, and adjust the inner-loop feedback gain parameter to make the inner-loop force tracking meet the preset inner-loop control performance index; S400: The sensor obtains the output parameters of the boom valve-controlled asymmetric cylinder, where the output parameters include the position and the pressure of the asymmetric cylinder, feedback the difference between the current position and the current position to the outer-loop position tracking controller and the inner-loop force tracking controller, feedback the pressure of the asymmetric cylinder to the inner-loop force tracking controller, and return to S200 to continue adjusting the outer-loop feedback gain parameter and the inner-loop feedback gain parameter, so that the outer-loop position tracking and the inner-loop force tracking meet the preset corresponding control performance indexes.

2. The method according to claim 1, characterized in that The flow continuity equation of the valve-controlled asymmetric cylinder established according to the parameter information in S100 is specifically: where, V1 = V 10 + A1x and V2 = V 20 - A2x are the effective volumes of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, V 10 and V 20 are the initial volumes of the rodless chamber, the rod chamber and the connected pipelines respectively, x is the equivalent load displacement, β e is the effective bulk modulus of elasticity, P1 and P2 are the pressures in the rodless chamber and the rod chamber of the hydraulic cylinder respectively, A1 and A2 are the effective working areas of the rodless chamber and the rod chamber of the hydraulic cylinder respectively, Q1 and Q2 are the valve port flows in the rodless chamber and the rod chamber of the hydraulic cylinder, and f1 and f2 represent the lumped disturbances in the rodless chamber and the rod chamber of the hydraulic cylinder respectively.

3. The method according to claim 2, wherein The valve port flow equation of the valve-controlled asymmetric cylinder established according to the parameter information in S100 is specifically: Among them, c1, c2, c3, and c4 are the gain coefficients of the electro-hydraulic proportional valve, which are determined by the shape and size of the valve orifice, and P S is the supply oil outlet pressure, and P T is the oil return port pressure; According to Newton's second law, the force balance equation of the valve-controlled asymmetric cylinder can be expressed as: where x is the equivalent load displacement, is the equivalent load velocity, is the equivalent load acceleration, m is the equivalent mass of the piston rod and the load, b represents the viscous friction coefficient, F is the driving force exerted on the system by the valve-controlled hydraulic cylinder, and f l represents the lumped disturbance term in the rodless chamber of the hydraulic cylinder in the force balance equation.

4. The method according to claim 3, wherein In S200, design an outer-loop nonlinear disturbance observer to dynamically estimate the outer-loop lumped disturbance in the force balance equation of the valve-controlled asymmetric cylinder, including: S210: Obtain the state-space expression of the equation based on the force balance equation of the valve-controlled asymmetric cylinder; S220: Design an outer-loop nonlinear disturbance observer according to the outer-loop lumped disturbance in the state-space expression to dynamically estimate the outer-loop lumped disturbance.

5. The method according to claim 4, wherein S210 is specifically: Define the state variables [x1, x2] T = [x, v] T , and according to the hydraulic cylinder force balance equation, the state space expression can be sorted out as follows: where x1 is the equivalent load displacement and x2 is the equivalent load velocity; Assume that the f of the lumped disturbance of the outer loop l rate of change is bounded, that is For the lumped disturbance f of the outer loop l , S220 is specifically: where Z is an auxiliary design variable and k1 is the observer gain to be designed, is the estimated value of the outer-loop lumped disturbance f l , and the estimation error is defined as If the outer-loop lumped disturbance f l satisfies the above assumptions, then by determining the specific value of the gain k1, the outer-loop nonlinear disturbance observer can ensure that the estimation error is uniformly bounded and stable.

6. The method according to claim 5, characterized in that In S200, design an outer-loop position tracking controller of the valve-controlled asymmetric cylinder based on the disturbance observer, and combine the current position, the desired position, and the expression of the outer-loop lumped disturbance estimation to obtain an expression of the virtual control input for outer-loop position tracking, including: S230: Design an outer-loop position tracking controller for a valve-controlled asymmetric cylinder based on a disturbance observer, and define a position error function according to the current position and the desired position; S240: Differentiate the position error function to obtain a differential expression of the position error function; S250: Obtain a virtual control input expression for outer-loop position tracking according to the expression of the outer-loop lumped disturbance estimation and the differential expression of the position error function.

7. The method according to claim 6, characterized in that, S230 specifically is: where x 1d and x1 are the expected position and the actual position of the equivalent load respectively, e1 represents the output position tracking error, and λ > 0 is the feedback gain; S240 specifically is: S250 specifically is: Among them, F d is the virtual control input for outer loop position tracking, k p , k v are respectively the outer loop feedback gain parameters.

8. The method according to claim 7, wherein S300 includes: S310: Define an inner-loop force tracking error function based on the virtual control input expression for outer-loop position tracking; S320: Differentiate the inner-loop force tracking error function, and combine the state-space parameters of the force balance equation, the flow continuity equation of the valve-controlled asymmetric cylinder, and the valve port flow equation to obtain a differential expression of the inner-loop force tracking error function; S330: Design an inner-loop nonlinear disturbance observer based on the inner-loop lumped disturbance in the differential expression of the inner-loop force tracking error function to dynamically estimate the inner-loop lumped disturbance; S340: Design an inner-loop force tracking controller for the valve-controlled asymmetric cylinder based on a disturbance observer based on the differential expression of the inner-loop force tracking error function and the expression of the inner-loop lumped disturbance estimation to obtain an inner-loop force tracking control input; S350: By adjusting the inner-loop feedback gain parameter, make the inner-loop force tracking meet the preset inner-loop control performance index.

9. The method according to claim 8, wherein S310 specifically is: e3 = F d -F(9) where, e3 is the force tracking error; S320 specifically is: where, 10. The method according to claim 9, characterized in that, Assume the change rates of f1 and f2 of the lumped disturbance in the flow continuity equation of the valve-controlled asymmetric cylinder are bounded, that is holds. Then, the change rate of the lumped disturbance d l composed of f1 and f2 is also bounded; S330 specifically is: where, Z is an auxiliary design variable, and k2 is the observer gain to be designed, is the estimated value of the lumped disturbance d l of the inner loop, and the estimation error is defined as If the lumped disturbance d l of the inner loop satisfies the above assumptions, then by determining the specific value of the gain k2, the inner loop disturbance observer can ensure that the estimation error is uniformly bounded and stable; S340 specifically is: where u is the inner-loop force tracking control input, and k f is the inner-loop feedback gain parameter.

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