Improved active disturbance rejection control design method based on error and input delay compensation

Abstract

The invention discloses an improved active-disturbance-rejection control method based on error and input delay compensation, relates to the technical field of industrial control, and aims to solve the problem of insufficient input delay and control precision of a high-order inertial system. The method comprises the following steps of: modeling a controlled object into a dynamic system with inertia characteristics, constructing an input delay compensation link and an error-based active-disturbance-rejection link, inputting a control error and a compensation value into an extended state observer (ESO), estimating an error related state quantity and a disturbance tracking value in real time, calculating a control quantity through a state error feedback control law, and compensating the control quantity; and closed-loop accurate adjustment is realized. The invention further comprises an improved second-order active-disturbance-rejection control scheme to adapt to higher precision requirements. The control structure is simplified, control signals and system output are synchronously controlled, the anti-interference capability and the tracking performance are considered, and the method can be widely applied to high-order inertial industrial system control in the fields of chemical engineering, thermal power generation and the like.

Description

Technical Field

[0001] This invention relates to the field of industrial control technology, and in particular to an improved active disturbance rejection control design method based on error and input delay compensation. Background Technology

[0002] Active disturbance rejection (ADRR) algorithms have attracted much attention and have been widely used in many fields due to their advantages such as simple structure, fast tracking speed, strong anti-interference ability, and strong robustness. ADRR algorithms have been successfully applied in systems such as robotics, aircraft control systems, rehabilitation motion control systems, and permanent magnet motor drives.

[0003] However, in typical industrial process control such as chemical engineering and thermal power generation, processes with large inertial characteristics exist, such as the superheated steam temperature system and main steam pressure system in thermal power units. These processes are typically described using higher-order inertial systems, i.e. ,in , , and ( () represent the differential operator, the steady-state gain, the time constant, and the order of the higher-order inertial system, respectively. and These represent the output and input of a high-order inertial system, respectively. Taking a superheated steam temperature system as an example, the meanings of the parameters in the above formula are: Output It is the main steam temperature at the superheater outlet of the superheater system, input. It refers to the opening degree of the desuperheating control valve and its steady-state gain coefficient. This refers to the amplification factor of the input value and the time constant of a higher-order inertial system. This refers to the time required for the system response to reach 63.2% of its steady-state value. In a superheated steam temperature system, when the system input is adjusted, due to the system's large inertia, the superheater outlet steam temperature will not immediately reach a new steady-state value, but will gradually change over time. Time constant It is an indicator that measures the speed of this change. The larger the value, the greater the system's inertia and the slower its response.

[0004] To address the control challenges of high-order inertial systems, Chinese patent application CN108287466A proposes an improved active disturbance rejection control algorithm implementation scheme, the process of which is as follows: Figure 1As shown: The actual controlled object is described as a higher-order system consisting of first-order inertial links connected in series. A compensation algorithm is used to compensate the input value of the previous calculation step of the selected higher-order system to obtain the compensation value of the current calculation step. The tracking value of the output value and the tracking value of the first derivative of the output value of the selected higher-order system in the next calculation step are estimated by an extended state observer (ESO). The input values ​​of the two calculation steps in the higher-order system are obtained by subtracting the difference between the output setpoint of the next calculation step and the tracking value of the output value of the next calculation step of the system, amplified by a proportional coefficient, and then subtracting the observed value of the total disturbance. This allows the system to adjust the change of the actuator in real time according to the calculation results. However, this existing technology does not design direct observation logic for control errors and still adopts the traditional approach of tracking the system output, resulting in room for further simplification of the control structure. At the same time, its collaborative design of input delay compensation and error control is insufficient, failing to fully utilize the role of error feedback in improving control accuracy, and making it difficult to meet the high-precision control requirements of higher-order inertial systems in complex industrial scenarios.

[0005] In summary, existing active disturbance rejection control technology has room for improvement in input delay compensation and error coordination control of high-order inertial systems. There is an urgent need for an improved solution that can synchronize control signals and system output, simplify the control structure, and improve control accuracy. Summary of the Invention

[0006] The purpose of this invention is to provide an improved active disturbance rejection control design method based on error and input delay compensation. By designing control errors, the extended state observer can directly track the system error, and by designing input delay compensation links, the input quantity and the output of the controlled object are more synchronized, so as to ensure that the closed-loop system has ideal control effect. This provides strong support for the widespread application of improved active disturbance rejection control algorithms based on error and input delay compensation in solving a class of high-order inertial industrial systems.

[0007] To achieve the above objectives, this invention provides an improved active disturbance rejection control design method based on error and input delay compensation, the steps of which are as follows: S1. Model the controlled object as a dynamic system with inertial characteristics, and clarify the input, output and core parameters of the system in each calculation step; S2. Construct an input delay compensation loop, perform compensation calculations based on historical input information of the system, and output a compensation value that matches the response characteristics of the controlled object; S3. Construct an error-based active disturbance rejection control loop, calculate the control error between the current setpoint and the output value of the system, and input the control error and the compensation value from step S2 into the extended state observer. S4. The control error and the disturbances to the system are estimated in real time by using an extended state observer to obtain the error-related state variables and the tracking values ​​of the disturbances. S5. Based on the tracking value, the subsequent step sequence value of the input quantity of the control algorithm is calculated through the state error feedback control law; S6. The input quantity obtained in step S5 is processed by the input delay compensation algorithm to obtain the subsequent step sequence compensation value, and the closed-loop system control quantity is adjusted to achieve precise regulation of the output of the controlled object.

[0008] Preferably, in step S1, the dynamic system containing inertial characteristics is a high-order inertial system, and its mathematical expression is: (1) in, , These are the output and input of the higher-order inertial system, respectively, and are used in the calculation step k as... and Let s represent the differential operator, K represent the steady-state gain of the higher-order inertial system, T represent the time constant, and n represent the order, where n≥3.

[0009] Preferably, in S2, the mathematical expression for the input delay compensation stage is: (2) in, , These are the output and input quantities of the compensation algorithm, respectively, and are used in each calculation step as follows: and express, This represents the time constant of the compensation process.

[0010] Preferably, under ideal operating conditions, the time constant of the compensation element satisfies the same condition as the time constant of the higher-order inertial system. .

[0011] Preferably, in step S3, the control error The calculation formula is: (3) in, This is the set value for the current calculation step sequence of the system. This is the output value of the current calculation step sequence of the system.

[0012] Preferably, in step S4, the error-related state quantity is the next calculation step for the control error. Tracking value The tracking value of the disturbance is the tracking value of the next calculation step of the total disturbance. The algorithm expression for the extended state observer is: (4) in, The compensation value is obtained through the compensation algorithm. Represents system gain. Represents the sampling step size. and The gain representing the ESO is directly related to the bandwidth of the ESO and is determined using the parametric bandwidth method. The expression is: (5) in, The bandwidth represents the extended state observer; The larger the value, the stronger the observation capability of ESO. The smaller the value, the weaker the observation capability of ESO.

[0013] Preferably, in step S5, the subsequent step values ​​of the control algorithm input are the input values ​​of the next two calculation steps. Its mathematical expression is: (6) in, To calculate the coefficients, This represents the system gain.

[0014] Preferably, in step S6, the subsequent step compensation value is the compensation value of the next three calculation steps. Through input delay compensation algorithm The processed data is used to adjust the control input of the closed-loop system, thereby enabling the output of the higher-order inertial system. y ( k ) regulation.

[0015] An improved second-order active disturbance rejection control method based on error and input delay compensation includes steps S1-S3, and the following steps: S4. Use the extended state observer algorithm to control the error. and compensation value Perform real-time estimation to obtain the next calculation step for the control error. Tracking value The tracking value of the first derivative of the numerical value in the next calculation step to control error. and the tracking value of the next calculation step under the total disturbance. The algorithm expression is: (7) in, Represents the sampling step size. , and The gain of the ESO is related to its bandwidth and is determined using the parametric bandwidth method. Its expression is: (8) in, Represents controller bandwidth. Represents the bandwidth of the extended state observer. The larger the value, the stronger the observation capability of ESO. The smaller the value, the weaker the observation capability of ESO; S5. Through the state error feedback control algorithm, by , , The next two computational steps to obtain the input values ​​for the improved second-order active disturbance rejection control algorithm based on error and input delay compensation are as follows: Its mathematical expression is: (9) in, , The representative calculation coefficient is related to the controller bandwidth, and the calculation formula is: (10) S6, will After processing by the input delay compensation algorithm, the compensation values ​​for the next three calculation steps are obtained. Adjusting the control quantity of the closed-loop system allows for the regulation of the output of the controlled object.

[0016] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention proposes an improved active disturbance rejection control (ADRC) design based on error and input delay compensation for high-order inertial systems with large inertial characteristics. It combines error-based ADRC with an input delay compensation algorithm, retaining the advantages of existing improved ADRC algorithms that balance tracking and anti-interference capabilities. By using input delay compensation to synchronize the control signal with the system output entering the extended state observer, the extended state observer obtains a more accurate estimate of the system state. Simultaneously, it simplifies the control process, allowing the extended state observer to directly track the control error instead of the system output value, transforming the two-degree-of-freedom structure into a one-degree-of-freedom structure. This not only simplifies the structure but also improves performance, enhancing its competitiveness in practical industrial applications.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a block diagram of the existing improved active disturbance rejection control algorithm.

[0020] Figure 2 This is an implementation step of an improved active disturbance rejection control method based on error and input delay compensation according to an embodiment of the present invention.

[0021] Figure 3 This is a block diagram of the algorithm structure of an improved active disturbance rejection control method based on error and input delay compensation according to an embodiment of the present invention.

[0022] Figure 4 This is a comparison chart of the set value, the output value of the method of the present invention, and the output value of the comparison method when the controlled object is a superheated steam temperature system, according to an embodiment of the present invention.

[0023] Figure 5 This is a block diagram of the algorithm structure of an improved second-order active disturbance rejection control method based on error and input delay compensation according to an embodiment of the present invention. Detailed Implementation

[0024] 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1 Taking the superheated steam temperature system of a thermal power unit as an example, this invention proposes an improved active disturbance rejection control design method based on error and input delay compensation, the structure of which is as follows: Figure 3 As shown, the process is as follows: Figure 2 As shown, it includes the following steps: S1: The superheated steam temperature system of the thermal power unit is described using a high-order inertial system, and the mathematical expression is: (1) Among them, the output of the higher-order inertial lag system and input In each calculation step, respectively using and express, To calculate the step sequence, s, , and n ( ) represent the differential operator, the steady-state gain, the time constant, and the order of the higher-order inertial system, respectively.

[0027] It should be noted that in this embodiment, the superheated steam temperature system of the thermal power unit adopts cascade control, which is divided into a pilot zone and an inert zone. The order difference between the two is significant. The pilot zone, as the inner loop control, adopts proportional control, and its inner loop proportional control parameters are as follows: The values ​​of the remaining parameters in the expression are respectively , and The parameters of the inert region are as follows: , and ; S2: For the superheated steam temperature system of the thermal power unit in step S1, an input delay compensation circuit is constructed, and the mathematical expression is: (2) Among them, the output of the compensation algorithm and input volume In each computational step, respectively and , Represents the differential operator, The time constant of the compensation process, under ideal conditions. , ( () represents the order; in this embodiment, let , The input to the compensation algorithm is the input value of the system in the previous calculation step. The output is the compensation value after compensation in the current calculation step. ; S3. Construct an error-based active disturbance rejection mechanism based on the setpoint of the current calculation step sequence of the superheated steam temperature system. and output value The control error is calculated and expressed as: (3) in This is the set value for the current calculation step sequence of the system. This is the output value of the current calculation step sequence of the system.

[0028] and error signal The compensation value obtained from the compensation algorithm for the current computation step sequence Input to the Extended State Observer (ESO).

[0029] S4: Regarding the error signal obtained through calculation in step S3 Compensation value obtained by the compensation algorithm An extended state observer algorithm is used for real-time estimation and compensation calculations. This yields the next calculation step value for the superheated steam temperature system control error. Tracking value And the tracking value of the next calculation step under the total disturbance. ; and The extended state observer algorithm is as follows: (4) in, For system gain, This is the sampling step size; and The gain of the ESO is directly related to its bandwidth and can be determined using the parametric bandwidth method, which is mathematically expressed as follows: (5) in, To expand the bandwidth of the state observer, its size directly affects the observation speed of the ESO. The larger the value, the stronger the ESO's observation capabilities. The smaller the value, the weaker the observation capability of the ESO; in this embodiment, , and ; S5: Calculate the control error of the superheated steam temperature system obtained in step S4 in the next step. Tracking value And the tracking value of the next calculation step in response to the total disturbance to the system. The numerical values ​​of the two calculation steps under the control quantity of the improved active disturbance rejection control algorithm based on error and input delay compensation are obtained through the state error feedback control algorithm. ; It can be calculated using the following formula: (6) in, In order to calculate the coefficients, in this embodiment The value is 0.063; S: The input values ​​of the improved active disturbance rejection control algorithm based on error and input delay compensation obtained in step S5 are processed by the input delay compensation algorithm to obtain the compensation values ​​for the next three calculation steps. This allows for the adjustment of the control quantity of the superheated steam temperature system, thereby enabling the regulation of the superheater outlet steam temperature.

[0030] Figure 4A comparison chart of the setpoint, output value of the method of this invention, and output value of the comparison method is shown when the controlled object is a superheated steam temperature system of a thermal power unit described by a high-order inertial system. The model parameters of the high-order inertial system are as follows: For the lead-in region, there are... , and For the inert region, there is , and The parameters of the improved active disturbance rejection control algorithm based on error and input delay compensation of the present invention are as follows: , , and The comparison method is a second-order active disturbance rejection control algorithm based on the fruit fly algorithm, with the following parameters: , , and The dashed line represents the setpoint of the superheated steam temperature system; the solid line represents the output value of the improved ADRC based on error and input delay compensation proposed in this invention; and the double dashed line represents the output value of a second-order ADRC based on the fruit fly algorithm, which is used as a comparison method.

[0031] The specific simulation process is as follows: At the start of the simulation, the system is in a steady state. At 500s, the setpoint is changed from 0 to 1. At 2000s, the control variable of the inner loop is perturbed, changing from 0 to 1. After the system stabilizes, at 4000s, the control variable of the outer loop is perturbed, also changing from 0 to 1, until the system reaches a steady state at 6000s. Simulation results show that when the controlled object is a high-order inertial system, compared with the comparative method, the method of this invention, while ensuring anti-interference capability, has a faster tracking speed and improves the control quality of the system.

[0032] Example 2 This invention proposes an improved second-order active disturbance rejection control design method based on error and input delay compensation, the structure of which is as follows: Figure 5 As shown, it includes the following steps: S1. The superheated steam temperature system of a certain type of thermal power unit is described using a high-order inertial system, and its mathematical expression is: (1) Among them, the output of the higher-order inertial system and input In each calculation step, respectively using and express, To calculate the step sequence, Represents the differential operator, Represents the steady-state gain of a high-order inertial system. The time constant is represented by n (n≥3), and the order is represented by n. S2. For the superheated steam temperature system of the thermal power unit in step S1, an input delay compensation circuit is constructed, the mathematical expression of which is: (2) Among them, the output of the compensation algorithm and input volume In each computational step, respectively and , Represents the differential operator, The time constant of the compensation process, under ideal conditions. , ( The ) represents the order; the input to the compensation algorithm is the input value of the system in the previous calculation step. The output is the compensation value after compensation in the current calculation step. ; S3. Construct an error-based active disturbance rejection mechanism based on the current system setpoint. and output value The control error is calculated and expressed as: (2) and error signal The compensation value obtained from the compensation algorithm for the current computation step sequence Input to the Extended State Observer (ESO); S4. Regarding the error signal obtained through calculation in step S3. Compensation value obtained by the compensation algorithm An extended state observer algorithm is used for real-time estimation and compensation calculations. This yields the next step value for the control error of the high-order inertial system. Tracking value The next calculation step value for controlling error Tracking value of the first derivative And the tracking value of the next calculation step under the total disturbance. ; , and The extended state observer algorithm is as follows: (7) in, Represents system gain. Represents the sampling step size. , and The gain of the ESO is related to its bandwidth and can be determined using the parametric bandwidth method, expressed as: (8) in, Represents controller bandwidth. This represents the bandwidth of the extended state observer (ESO), and its size directly affects the observation speed of the ESO. The larger the value, the stronger the ESO's observation capabilities. The smaller the value, the weaker the observation capability of ESO; S5. Calculate the higher-order inertial system control error obtained in step S4 using the next step's numerical values. Tracking value The next calculation step value for controlling error Tracking value of the first derivative And the tracking value of the next calculation step in response to the total disturbance to the system. The numerical values ​​of the two computational steps under the input values ​​of the improved second-order active disturbance rejection control algorithm based on error and input delay compensation are obtained through the state error feedback control algorithm. The expression is as follows: (9) in, , The representative calculation coefficient, which is related to the controller bandwidth, can be calculated using the following formula: (10) S6. The input values ​​of the improved active disturbance rejection control algorithm based on error and input delay compensation obtained in step S5 are processed by the input delay compensation algorithm to obtain the compensation values ​​for the next three calculation steps. This allows for the adjustment of control quantities in the closed-loop system, thereby enabling the regulation of the output of the higher-order inertial system.

[0033] The remaining technical features in the above embodiments can be flexibly selected by those skilled in the art to meet different specific practical needs according to actual circumstances. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims. In the above description, numerous specific details have been set forth to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other instances, to avoid obscuring the present invention, well-known techniques, such as specific construction details, operating conditions, and other technical conditions, have not been specifically described.

[0034] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An improved active disturbance rejection control design method based on error and input delay compensation, characterized in that, The steps are as follows: S1. Model the controlled object as a dynamic system with inertial characteristics, and clarify the input, output and core parameters of the system in each calculation step; S2. Construct an input delay compensation loop, perform compensation calculations based on historical input information of the system, and output a compensation value that matches the response characteristics of the controlled object; S3. Construct an error-based active disturbance rejection control loop, calculate the control error between the current setpoint and the output value of the system, and input the control error and the compensation value from step S2 into the extended state observer. S4. The control error and the disturbances to the system are estimated in real time by using an extended state observer to obtain the error-related state variables and the tracking values ​​of the disturbances. S5. Based on the tracking value, the subsequent step sequence values ​​of the input quantity of the control algorithm are calculated through the state error feedback control law; S6. The input quantity obtained in step S5 is processed by the input delay compensation algorithm to obtain the subsequent step sequence compensation value, and the closed-loop system control quantity is adjusted to achieve precise regulation of the output of the controlled object.

2. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 1, characterized in that: In step S1, the dynamic system containing inertial characteristics is a high-order inertial system, and its mathematical expression is: （1） in, , These are the output and input of the higher-order inertial system, respectively, and are used in the calculation step k as... and Let s represent the differential operator, K represent the steady-state gain of the higher-order inertial system, T represent the time constant, and n represent the order, where n≥3.

3. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 2, characterized in that: In S2, the mathematical expression for the input delay compensation stage is: （2） in, , These are the output and input quantities of the compensation algorithm, respectively, and are used in each calculation step as follows: and express, This represents the time constant of the compensation process.

4. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 3, characterized in that: Under ideal conditions, the time constant of the compensation element satisfies the same condition as the time constant of the higher-order inertial system. .

5. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 3, characterized in that: In step S3, the control error The calculation formula is: （3） in, This is the set value for the current calculation step sequence of the system. This is the output value of the current calculation step sequence of the system.

6. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 5, characterized in that: In step S4, the error-related state quantity is the next calculation step for the control error. Tracking value The tracking value of the disturbance is the tracking value of the next calculation step of the total disturbance. The algorithm expression for the extended state observer is: （4） in, The compensation value is obtained through the compensation algorithm. Represents system gain. Represents the sampling step size. and The gain representing the ESO is directly related to the bandwidth of the ESO and is determined using the parametric bandwidth method. The expression is: （5） in, The bandwidth represents the extended state observer; The larger the value, the stronger the observation capability of ESO. The smaller the value, the weaker the observation capability of ESO.

7. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 6, characterized in that: In step S5, the input values ​​of the control algorithm in subsequent steps are the input values ​​of the next two calculation steps. Its mathematical expression is: （6） in, To calculate the coefficients, This represents the system gain.

8. The improved active disturbance rejection control design method based on error and input delay compensation according to claim 7, characterized in that: In step S6, the subsequent step compensation value is the compensation value of the next three calculation steps. Through input delay compensation algorithm The processed data is used to adjust the control input of the closed-loop system, thereby enabling the output of the higher-order inertial system. y ( k ) regulation.

9. An improved second-order active disturbance rejection control method based on error and input delay compensation, characterized in that, Includes steps S1-S3 as described in any one of claims 1, 2, 3, 4, and 5, as well as the following steps: S4. Use the extended state observer algorithm to control the error. and compensation value Perform real-time estimation to obtain the next calculation step for the control error. Tracking value The tracking value of the first derivative of the numerical value in the next calculation step to control error. and the tracking value of the next calculation step under the total disturbance. The algorithm expression is: （7） in, Represents the sampling step size. , and The gain of the ESO is related to its bandwidth and is determined using the parametric bandwidth method. Its expression is: （8） in, Represents controller bandwidth. Represents the bandwidth of the extended state observer. The larger the value, the stronger the observation capability of ESO. The smaller the value, the weaker the observation capability of ESO; S5. Through the state error feedback control algorithm, by , , The next two computational steps to obtain the input values ​​for the improved second-order active disturbance rejection control algorithm based on error and input delay compensation are as follows: Its mathematical expression is: （9） in, , The representative calculation coefficient is related to the controller bandwidth, and the calculation formula is: （10） S6, will After processing by the input delay compensation algorithm, the compensation values ​​for the next three calculation steps are obtained. Adjusting the control quantity of the closed-loop system allows for the regulation of the output of the controlled object.

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