A method for controlling the frequency of a pile driver vibration based on an expert active disturbance rejection controller

Abstract

The application discloses a kind of based on expert self-disturbance controller's piling machine vibration frequency control method, first utilize the differential tracker in self-disturbance controller to the input signal arrangement transition process and extract its differential signal, then expansion observer carries out real-time dynamic estimation and compensation to the total disturbance of system, then the output of differential tracker is combined with the output of expansion observer and is input to expert controller and nonlinear combination link, expert controller is adapted to the key parameters of nonlinear combination link according to input range, finally the output of nonlinear combination link is combined with the total disturbance estimation value of state observer output and acts on motor, motor drives eccentric block to realize the frequency control of vibration hammer.The application overcomes the contradiction between the rapidity and overshoot of traditional control algorithm, greatly improves the robustness of system, and can be widely used in the frequency control of hydraulic vibration piling machine, and has good control effect.

Description

Technical Field

[0001] This invention belongs to the research field, specifically relating to a method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller. Background Technology

[0002] With the increasing application of hydraulic vibratory pile drivers in the engineering field, the outdated theory and immature products of domestic vibratory pile hammers can no longer meet market demands. Compared with traditional pile drivers, hydraulic vibratory pile drivers have advantages such as a wide operating environment, strong impact force, light weight, good pile driving quality, low vibration pollution, and ease of use. The common control method for hydraulic vibratory pile drivers is synchronous control, which uses the centrifugal force generated by two sets of eccentric blocks driven by dual motors to drive piles. The vibration frequency can be adjusted by adjusting the rotation speed of the eccentric blocks. However, due to factors such as load changes and nonlinear friction of hydraulic actuators, the system has extremely high requirements for vibration frequency control. This invention innovates the frequency control technology for vibratory pile drivers.

[0003] Currently, vibration frequency control methods for hydraulic pile drivers include PID control, sliding mode control, neural network control, and fuzzy control. While each control technology can enable pile drivers to have a certain degree of adaptive adjustment in vibration frequency and impact force control, it still has many drawbacks. PID control suffers from the contradiction between overshoot and speed, slow response, adjustment only after errors occur, and poor anti-disturbance capability. Sliding mode control, due to its discontinuous control, will experience unavoidable "chattering" in real time, which is mutually restrictive with anti-interference performance. Neural network control relies heavily on the network model and requires a large amount of data samples for long-term training, which is obviously inconvenient. In fuzzy control, the establishment of fuzzy rules determines the control effect, and the establishment of rules requires expert experience. Due to numerous interference factors such as hydraulic oil leakage, external load changes, and environmental changes, the frequency control requirements for pile drivers are extremely high. Therefore, it is necessary to conduct important research on frequency control technology for vibratory pile drivers. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the aforementioned frequency control algorithms by combining expert control and an active disturbance rejection controller (ADRC) into an expert ADRC. This overcomes the shortcomings of using only a single controller, enabling intelligent adjustment of the ADRC parameters and resulting in improved nonlinear control and anti-interference performance for the pile driver in frequency control. This method provides new insights for subsequent research and engineering applications of ADRC fusion algorithms in the control of vibratory pile drivers.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] The present invention proposes a method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller, comprising the following steps:

[0007] S1. After converting the desired vibration frequency of the pile driver system into the desired motor speed, the desired motor speed is tracked by the differential tracker of the active disturbance rejection controller, and its differential signal is extracted.

[0008] S2. Real-time dynamic estimation and compensation of uncertain disturbances in the pile driver system are performed using the extended state observer of the active disturbance rejection controller;

[0009] S3. The output of the differential tracker is combined with the output of the state observer and then input into the expert controller to adaptively adjust the key parameters of the nonlinear combination link in real time.

[0010] S4. Through a nonlinear combination process, the two-dimensional data of the combination of the output of the differential tracker and the output of the state observer are combined nonlinearly to achieve optimal combination.

[0011] S5. The output of the nonlinear combination element is combined with the total disturbance estimate output by the state observer and then input into the motor.

[0012] S6. Adjust the motion control parameters, collect motor speed data, and analyze it. The motor drives the eccentric block to move, thereby realizing the vibration control of the pile driver.

[0013] Furthermore, in step S1, the algorithm design of the differential tracker is as follows:

[0014]

[0015] in,

[0016] d=rh, d0=dh, y=x1(k)-v(k)+hx2(k),

[0017] v(k) is the desired motor speed; x1(k) is the tracking signal of v(k), x2(k) is the differential signal of x1(k), x1(k) and x2(k) are the outputs of the differential tracker; h is the filtering factor, which determines the filtering effect of noise; r is the speed factor, which determines the tracking speed of the signal; d, d0, y, and a0 are intermediate variables.

[0018] Furthermore, in step S2, the algorithm design for the extended state observer is as follows:

[0019]

[0020] Where, e = z1(k) - y(k),

[0021] u(k) is the motor speed control variable, y(k) is the actual motor speed, and u(k) and y(k) are the inputs of the extended state observer; z1(k) is the tracking signal of y(k), z2(k) is the differential tracking signal of y(k), z3(k) is the estimated value of the total disturbance, and z1(k), z2(k), and z3(k) are the outputs of the extended state observer; β 01 β 02 β 03 b0 is a parameter that needs to be adjusted manually, and h is the sampling step size.

[0022] Furthermore, in step S3, the algorithm design of the expert controller is as follows:

[0023] Let e1(k), e2(k), and e2(k-1) represent the error and differential error of the current sampling period and the differential error of the previous sampling period, respectively; k1' and k2' are the initial output values; E1 and E2 are the error limits, where E1>E2; c1, c2, c3, c4, and c5 are the amplification coefficients, where c1>c3, c2>c4, and c6, c7, c8, c9, and c5 are the amplification coefficients. 10 The suppression coefficients are: c7 > c9, c8 > c 10 The expert control law is as follows:

[0024] When |e1(k)|≥E1, the absolute value of the error is very large. Therefore, the controller output should be maximized to allow the system to reach a steady state as quickly as possible. The controller output is:

[0025]

[0026] When e1(k)e2(k)>0:

[0027] If |e1(k)|≥E2, the error is changing towards a larger value and the absolute value of the error is large. Therefore, the controller output should be maximized to allow the system to reach a steady state more quickly. The controller output should be:

[0028]

[0029] If |e1(k)| < E2, it indicates that the error is changing in the direction of increasing magnitude but the absolute value of the error is small. Using general control, the controller output is:

[0030]

[0031] When e1(k)e2(k)<0, e2(k)e2(k-1)>0, or e1(k)=0, it indicates that the error is changing towards a smaller value, or that it has reached a stable state. The controller remains unchanged, and the output value is the same as the previous cycle. The controller output is:

[0032]

[0033] When e1(k)e2(k)<0 and e2(k)e2(k-1)<0:

[0034] If |e1(k)|≥E2, it indicates that the absolute value of the error is large and the system is in an extreme state. Therefore, the controller output should be maximized to allow the system to reach a steady state more quickly. The controller output is:

[0035]

[0036] If |e1(k)| < E2, it indicates that the absolute value of the error is small and the error is changing in the direction of decreasing. Therefore, the controller output should be smaller, and its output will be:

[0037]

[0038] When |e1(k)|≤ε, it indicates that the absolute value of the error is very small, and the controller output should be small. The controller output is:

[0039]

[0040] Furthermore, in step S4, the nonlinear combination algorithm is designed as follows:

[0041] u0=k1fal(e1,0.5,δ)+k2fal(e2,0.25,δ)

[0042] Where δ is the sampling compensation h, e1 and e2 are the error and differential error of the speed tracking signal, respectively, k1 and k2 are the outputs of the expert controller; e1, e2, k1, and k2 are the inputs of the nonlinear combination element; and u0 is the output result of the combination.

[0043] Beneficial effects: This invention utilizes a phase sensor to measure the motor's rotational speed, and then employs an active disturbance rejection controller (ADRC) to achieve adaptive control of the motor's rotational speed, thereby servo-controlling the vibration frequency of the pile driver. A differential tracker tracks the desired rotational speed and its differential signal, and an expert controller adaptively adjusts key parameters of the nonlinear combination components in the ADRC based on the tracking signal, improving system robustness. The adaptive control based on a "black box" model simplifies the system structure and reduces computational complexity. This solution overcomes the shortcomings of traditional algorithm models, such as complex design and poor robustness, significantly improving the stability, accuracy, and speed of vibration frequency control in pile drivers. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the vibration frequency control system for a pile driver.

[0045] Figure 2 This is a schematic diagram of vibration frequency control for a pile driver based on an expert controller.

[0046] Figure 3 The image shows the results of the experimental simulation. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to embodiments.

[0048] The vibration frequency control method for a pile driver based on an expert active disturbance rejection controller of the present invention includes the following steps: First, a differential tracker is used to track the desired speed of the motor and its differential signal. Then, an extended state observer is used to estimate the total external disturbance of the system in real time and to extract the actual speed of the motor and its differential signal. Then, the difference between the actual speed and its differential signal extracted by the state observer and the desired speed and its differential signal extracted by the differential tracker is respectively input into a nonlinear combination link and an expert controller. The expert controller adaptively adjusts the key parameters of the nonlinear combination link according to the error. Finally, the output of the nonlinear combination link and the disturbance compensation estimated by the extended state observer are combined and output to the electro-hydraulic drive circuit. The circuit drives the motor to rotate, and the motor drives the eccentric block to move periodically, thus realizing the vibration frequency control of the pile driver.

[0049] The present invention is applicable to the adaptive control of vibration frequency of hydraulic pile drivers. To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below with reference to the accompanying drawings:

[0050] like Figure 1 The diagram shows a schematic of a pile driver vibration frequency control system. Based on the system input of the desired motor speed v and the sensor-measured actual motor speed y, the speed error e is calculated. The vibration frequency controller drives the motor according to the error control drive circuit, ensuring the pile driver's output frequency f reaches the desired value. A good vibration frequency controller enables the system to quickly and accurately track the motor speed, while exhibiting small overshoot and strong anti-interference capability. Therefore, this invention employs an expert controller and an active disturbance rejection controller to achieve precise control of the pile driver's vibration frequency, specifically as follows... Figure 2 As shown.

[0051] exist Figure 2In the process, the system inputs the desired motor speed, the differential tracker tracks the desired speed x1 and its differential signal x2, the extended observer solves for the total disturbance z3, the speed estimate z1 and its differential signal z2 based on the actual motor speed y measured by the sensor, the nonlinear combination element solves for u0 based on the differences e1 and e2 between x1 and z1, and between x2 and z2, and the expert controller also solves for the adaptive parameters k1 and k2 of the nonlinear combination element based on e1 and e2. The output of the nonlinear combination element is combined with the compensation z3 and input into the motor speed control output, and finally the motor drives the eccentric block to achieve vibration frequency control of the pile driver. The specific implementation steps are as follows:

[0052] Step 1: Track the desired motor speed using a differential tracker and extract the differential signal of the tracking result. The differential tracker is designed as follows:

[0053]

[0054] in,

[0055] d=rh, d0=dh, y=x1(k)-v(k)+hx2(k), v(k) is the desired motor speed and is the input of the differential tracker. x1(k) is the tracking signal of v(k), x2(k) is the differential signal of x1(k), and x1(k) and x2(k) are the outputs of the differential tracker. h is the filtering factor, which determines the noise filtering effect, r is the speed factor, which determines the signal tracking speed, and d, d0, y, and a0 are intermediate variables. In this design, r = 100 and h = 0.005 are taken.

[0056] Step 2: Obtain the actual rotational speed of the motor using the phase sensor mounted on the pile driver.

[0057] Step 3: Observe the motor speed state and total disturbance using an extended state observer. The extended state observer is designed as follows:

[0058]

[0059] Where, e = z1(k) - y(k),

[0060] u(k) is the motor speed control variable, y(k) is the actual motor speed, and u(k) and y(k) are the inputs of the extended state observer. z1(k) is the tracking signal of y(k), z2(k) is the differential tracking signal of y(k), z3(k) is the estimated value of the total disturbance, and z1(k), z2(k), and z3(k) are the outputs of the extended state observer. β 01 β 02 β 03Here, β is the parameter that needs to be manually adjusted, b0 is the compensation factor, and h is the sampling step size. In this design, β is used. 01 =33,β 02 =363, β 03 =1331, b0=5, h=0.005.

[0061] Step 4: Solve for the error of the speed tracking signal and the differential error of the speed tracking signal using the results of the extended state observer and the differential tracker. Specifically:

[0062]

[0063] x1(k) is the tracking signal of v(k), x2(k) is the differential signal of x1(k), z1(k) is the tracking signal of y(k), z2(k) is the differential tracking signal of y(k), e1 is the error of the speed tracking signal, and e2 is the differential error of the speed tracking signal.

[0064] Step 5: The expert controller adjusts k1 and k2 of the nonlinear feedback loop based on the error e1 and the differential error e2 of the motor speed tracking signal. Specifically:

[0065] Let e1(k), e2(k), and e2(k-1) represent the error and differential error of the current sampling period and the differential error of the previous sampling period, respectively; k1' and k2' are initial values; E1 and E2 are error limits, where E1>E2; and c1, c2, c3, c4, and c5 are amplification coefficients, where c1>c3, c2>c4, and c6, c7, c8, c9, and c5 are amplification coefficients. 10 The suppression coefficients are: c7 > c9, c8 > c 10 In this design, we take k1' = 0.8, k2' = 0.7, E1 = 15, E2 = 7, c1 = 4.2, c2 = 3.7, c3 = 1.9, c4 = 1.8, c5 = 2.6, c6 = 0.8, c7 = 0.8, c8 = 0.6, c9 = 0.1, c 10 =0.1, the expert control law is designed as follows:

[0066] 1) When |e1(k)|≥E1, the absolute value of the error is very large. Therefore, the controller output should be maximized to allow the system to reach a steady state as quickly as possible. The controller output is:

[0067]

[0068] 2) When e1(k)e2(k)>0:

[0069] ① If |e1(k)|≥E2, the error is changing towards a larger value and the absolute value of the error is large. Therefore, the controller output should be maximized to allow the system to reach a steady state more quickly. The controller output will be:

[0070]

[0071] ② If |e1(k)| < E2, it indicates that the error is changing in the direction of increasing magnitude but the absolute value of the error is small. Using general control, the controller output is:

[0072]

[0073] 3) When e1(k)e2(k)<0, e2(k)e2(k-1)>0, or e1(k)=0, it indicates that the error is changing towards a smaller value, or that it has reached a stable state. The controller remains unchanged, and the output value is the same as the previous cycle. The controller output is:

[0074]

[0075] 4) When e1(k)e2(k)<0 and e2(k)e2(k-1)<0:

[0076] ① If |e1(k)|≥E2, it indicates that the absolute value of the error is large and the system is in an extreme state. In this case, the controller output should be maximized to allow the system to reach a steady state more quickly. The controller output is:

[0077]

[0078] ② If |e1(k)| < E2, it indicates that the absolute value of the error is small and the error is changing in the direction of decreasing. The controller output should be smaller, and its controller output is:

[0079]

[0080] 5) When |e1(k)|≤ε, it indicates that the absolute value of the error is very small, and the controller output should be made smaller. The controller output is:

[0081]

[0082] Step 6: Combine the error of the motor speed tracking signal with the differential error of the motor speed tracking signal through a nonlinear combination element. The nonlinear combination element is designed as follows:

[0083] u0=k1fal(e1,0.5,δ)+k2fal(e2,0.25,δ)

[0084] Where δ represents sampling compensation, e1 and e2 represent the error and differential error of the motor speed tracking signal, respectively, and k1 and k2 are the outputs of the expert controller. e1, e2, k1, and k2 are the inputs of the nonlinear combination element. u0 is the output result of the combination, which is taken as δ = 0.005 in this design.

[0085] Step 7: Based on the output of the nonlinear combined element and the disturbance compensation output of the extended state observer, the motor speed control quantity is generated, as follows:

[0086]

[0087] Where u0 is the output of the nonlinear combination, z3 is the estimated value of the total disturbance output by the extended state observer, and b0 is the compensation factor, which is b0 = 5 in this design.

[0088] Step 8: The speed control quantity is converted into a digital signal and input to the drive circuit. The motor speed is controlled through the electro-hydraulic circuit, and the motor drives the eccentric block to control the vibration frequency of the pile driver.

[0089] MATLAB simulation results are as follows Figure 3 As shown, curve "SET" represents the set speed, curve "ADRC" represents the response result of the active disturbance rejection controller, and curve "EADRC" represents the response result of the expert active disturbance rejection controller. By comparison, it can be seen that the control method based on the expert active disturbance rejection controller has a better effect on the vibration frequency control of the pile driver.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller, characterized in that, Includes the following steps: S1. After converting the desired vibration frequency of the pile driver system into the desired motor speed, the desired motor speed is tracked by the differential tracker of the active disturbance rejection controller, and its differential signal is extracted. S2. Real-time dynamic estimation and compensation of uncertain disturbances in the pile driver system are performed using the extended state observer of the active disturbance rejection controller; S3. The output of the differential tracker is combined with the output of the state observer and then input into the expert controller to adaptively adjust the key parameters of the nonlinear combination link in real time. S4. Through a nonlinear combination process, the two-dimensional data of the combination of the output of the differential tracker and the output of the state observer are combined nonlinearly to achieve optimal combination. S5. The output of the nonlinear combination element is combined with the total disturbance estimate output by the state observer and then input into the motor. S6. Adjust the motion control parameters, collect motor speed data, and analyze it. The motor drives the eccentric block to move, thereby realizing the vibration control of the pile driver. In step S3, the algorithm design of the expert controller is as follows: Let e1(k), e2(k), and e2(k-1) represent the error and differential error of the current sampling period and the differential error of the previous sampling period, respectively; k1' and k2' are the initial output values; E1 and E2 are the error limits, where E1>E2; c1, c2, c3, c4, and c5 are the amplification coefficients, where c1>c3, c2>c4, and c6, c7, c8, c9, and c5 are the amplification coefficients. 10 The suppression coefficients are: c7 > c9, c8 > c 10 The expert control law is as follows: when When the absolute value of the error is large, the controller output should be maximized to allow the system to reach a steady state as quickly as possible. The controller output will then be: ； when hour: if Since the error is increasing and its absolute value is large, the controller output should be maximized to allow the system to reach a steady state more quickly. The controller output should be: ； if This indicates that the error is changing in a larger direction but the absolute value of the error is small. Using general control, the controller output is: ； when , or When the error is decreasing or has reached a stable state, the controller remains unchanged, and the output value is the same as the previous cycle. The controller output is: ； when , hour: if This indicates that the absolute value of the error is large and the system is in an extreme state. The controller output should be maximized to allow the system to reach a stable state more quickly. The controller output is: ； if This indicates that the absolute value of the error is small and the error is changing in a direction of decreasing smaller values. Therefore, the controller output should be minimized, and its output is: ； when When the absolute value of the error is very small, the controller output should be kept small, and the controller output is: 。 2. The method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller according to claim 1, characterized in that: In step S1, the algorithm design of the differential tracker is as follows: ； in, , ; ， ， ， ； v(k) is the desired motor speed; x1(k) is the tracking signal of v(k), x2(k) is the differential signal of x1(k), x1(k) and x2(k) are the outputs of the differential tracker; h is the filtering factor, which determines the filtering effect of noise; r is the speed factor, which determines the tracking speed of the signal; d, d0, y, and a0 are intermediate variables.

3. The method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller according to claim 2, characterized in that: In step S2, the algorithm design for the extended state observer is as follows: ； in, , ; u(k) is the motor speed control variable, y(k) is the actual motor speed, and u(k) and y(k) are the inputs of the extended state observer; z1(k) is the tracking signal of y(k), z2(k) is the differential tracking signal of y(k), z3(k) is the estimated value of the total disturbance, and z1(k), z2(k), and z3(k) are the outputs of the extended state observer; β 01 β 02 β 03 b0 is a parameter that needs to be adjusted manually, h is the sampling step size, and δ is the sampling compensation.

4. The method for controlling the vibration frequency of a pile driver based on an expert active disturbance rejection controller according to claim 1, characterized in that: In step S4, the nonlinear combination algorithm is designed as follows: Where δ represents sampling compensation, e1 and e2 represent the error and differential error of the speed tracking signal, respectively, k1 and k2 represent the outputs of the expert controller, e1, e2, k1, and k2 represent the inputs of the nonlinear combination element, and u0 represents the output result of the combination.

Images