A controller and control method combining classical control and modern control

Abstract

The application discloses a controller combined with classical control and modern control and a control method, and relates to the technical field of automation control. The controller comprises an inner loop structure and an outer loop structure. The control strategy of the inner loop structure is a control strategy of a control method based on internal mechanism description. The control strategy of the outer loop structure is a control strategy for eliminating errors based on errors. The application combines classical control and modern control, greatly improves response speed, and retains the advantages of classical control and is not sensitive to model errors.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automation control technology, in particular to a controller combining classical control and modern control and a control method. BACKGROUND

[0002] The classical control theory is formed in the 1930s and developed maturely in the 1950s, and the research object is a single variable constant system with one input variable and one output variable and parameters not changing with time. The mathematical basis is Laplace transform, and the basic method for analyzing and synthesizing the system is frequency response and root locus method, usually using the transfer function between input and output as the mathematical model of the system.

[0003] The modern control theory is developed after the 1960s on the basis of the classical control theory. The state space method of linear control system, the concept of controllability and observability proposed by Kalman (R·E·Kalman) lay the foundation of the modern control theory, and Kalman filter is widely used in the analysis and control of stochastic control system. The maximum principle proposed by Pontryagin et al. deeply studies the optimal control problem, and dynamic programming proposed by Bellman (R·Bellman) is widely used in various optimal control problems.

[0004] However, both the classical control theory and the modern control theory have their own defects. The classical control theory is not suitable for time-varying systems and multivariable systems, and it is difficult to reveal the deeper characteristics of the system. The modern control theory is sensitive to model error angle. SUMMARY

[0005] The present application aims to provide a controller combining classical control and modern control and a control method, so as to improve the response speed.

[0006] To achieve the above purpose, the present application provides the following solutions:

[0007] A controller combining classical control and modern control, comprising: an inner loop structure and an outer loop structure;

[0008] The control strategy of the inner loop structure is a control strategy based on internal mechanism description;

[0009] The control strategy of the outer loop structure is a control strategy based on error to eliminate error.

[0010] Optionally, the outer loop structure comprises:

[0011] An error calculation unit for calculating an error value according to an input controlled variable and an output feedback variable;

[0012] a classical controller, configured to convert the error value into a classical control variable based on an outer loop control strategy, wherein the outer loop control strategy is a control strategy based on error to eliminate error;

[0013] the inner loop structure, configured to determine a controlled object control variable according to the classical control variable and an inner loop control strategy, wherein the controlled object control variable is an input of the controlled object, the output feedback variable is an output of the controlled object, and the inner loop control strategy is a control strategy based on an internal mechanism description control method.

[0014] Optionally, the inner loop structure at least comprises:

[0015] a modern controller, connected in parallel with the controlled object, configured to:

[0016] determine a modern control variable based on the inner loop control strategy and internal state information of the controlled object;

[0017] determine a controlled object control variable based on the classical control variable and the modern control variable.

[0018] Optionally, the classical controller is a PID controller or an active disturbance rejection controller.

[0019] Optionally, the modern controller is a sliding mode controller, an LQR controller, an explicit model controller or an implicit model controller.

[0020] Optionally, the classical control and modern control combined controller is applied to a multi-input and multi-output helicopter model, the controlled variable is a collective lever brake variable, a cyclic lever brake variable and a foot pedal brake variable, and the output feedback variable is a yaw angular velocity, a roll angular velocity and a pitch angular velocity.

[0021] To achieve the above object, the application further provides the following scheme:

[0022] A classical control and modern control combined control method, comprising:

[0023] calculating an error value according to an input controlled variable and an output feedback variable;

[0024] converting the error value into a classical control variable based on an outer loop control strategy, wherein the outer loop control strategy is a control strategy based on error to eliminate error;

[0025] determining a controlled object control variable according to the classical control variable and an inner loop control strategy, wherein the controlled object control variable is an input of the controlled object, the output feedback variable is an output of the controlled object, and the inner loop control strategy is a control strategy based on an internal mechanism description control method.

[0026] Optionally, the determining the controlled object control quantity according to the classical control quantity and the inner loop control strategy specifically comprises:

[0027] determining the modern control quantity based on the inner loop control strategy and the internal state information of the controlled object;

[0028] determining the controlled object control quantity based on the classical control quantity and the modern control quantity.

[0029] According to the specific embodiments provided by the present application, the following technical effects are disclosed.

[0030] The present application combines the classical control with the modern control, greatly improves the response speed, and meanwhile retains the advantages of the classical control, and is not sensitive to model error. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0032] Figure 1 a control structure diagram corresponding to the classical control method;

[0033] Figure 2 a control structure diagram corresponding to the modern control method;

[0034] Figure 3 a first control structure diagram after the classical controller and the modern controller of the present application are independently combined;

[0035] Figure 4 a second control structure diagram after the classical controller and the modern controller of the present application are independently combined;

[0036] Figure 5 a structure diagram of the controller combining the classical control and the modern control of the present application;

[0037] Figure 6 a structure diagram of the hidden model controller of the present application;

[0038] Figure 7 a structure diagram of the controller combining the PID controller and the hidden model controller of the present application;

[0039] Figure 8 a response comparison diagram of the controller combining the PID controller and the hidden model controller of the present application and the single hidden model controller;

[0040] Figure 9The figure is a response comparison diagram of a model error of 25% of a single hidden model controller and a controller combined by the PID controller and the hidden model controller of the present application;

[0041] Figure 10 The figure is a flowchart of a control method combined by a classical control and a modern control of the present application. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0043] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0044] From the control thought, the existing control methods are one control strategy of "eliminating error based on error" and one control strategy of "control method based on internal mechanism description". In view of the advantages of the above two control strategies, the present application combines the methods with different control strategies to achieve better control effect.

[0045] Since the classical control thought and the modern control thought are independent of each other and do not affect each other, the present application combines the classical control thought and the modern control thought, the inner ring is the modern control thought, and the outer ring is the classical control thought, so as to efficiently realize control.

[0046] The classical control method (common classical control methods include PID control method, active disturbance rejection control method, etc.) is as shown in Figure 1 The theoretical basis is frequency method and root locus method, and the effect of control is achieved by eliminating the error between input and output. The classical control method only cares about the input and output of the system, and is irrelevant to the internal state of the system running. Among them, the main function of the classical controller is to eliminate error, v0 is the input quantity, y is the output quantity, e is the error between input and output, and u is the control quantity.

[0047] The modern control method (common modern control methods include sliding mode control method, LQR control method, explicit model method, hidden model method, etc.) is as shown in Figure 2 The theoretical basis is state space method, and is closely related to the internal state of the system running. The present controller adjusts its internal state to the desired dynamic characteristics, so as to achieve the purpose of stable control. The main function of the present controller is to adjust the object to the desired dynamic characteristics, v0 is the input quantity, u is the control quantity, and y is the output quantity.

[0048] Two control methods are independent processes, and do not affect each other. Figure 3 and Figure 4 The combination shown in the figure is unreasonable, the dynamic characteristic adjustment of the modern controller is affected by the classical controller, the two methods are coupled, and good control effect cannot be achieved. e is a classical control quantity, u x is a modern control quantity, u is a total control quantity, y is an output quantity, and e is an error between an input and an output.

[0049] Therefore, the application provides a new classical control and modern control combined controller.

[0050] Embodiment one

[0051] The classical control and modern control combined controller provided in the embodiment includes an inner loop structure and an outer loop structure, as shown in the figure. Figure 5 The control strategy of the inner loop structure is a control strategy based on an internal mechanism description.

[0052] The control strategy of the outer loop structure is a control strategy based on an error to eliminate the error.

[0053] The outer loop structure includes an error calculation unit, a classical controller, and an inner loop structure.

[0054] The error calculation unit is configured to calculate an error value according to an input controlled quantity and an output feedback quantity.

[0055] The classical controller is configured to convert the error value into a classical control quantity based on an outer loop control strategy.

[0056] The outer loop control strategy is a control strategy based on an error to eliminate the error.

[0057] The inner loop structure is configured to determine a controlled object control quantity according to the classical control quantity and an inner loop control strategy.

[0058] The inner loop structure includes at least a modern controller connected in parallel with the controlled object.

[0059] The modern controller is configured to determine a modern control quantity based on the inner loop control strategy and internal state information of the controlled object.

[0060] The controlled object control quantity is determined based on the classical control quantity and the modern control quantity.

[0061] Preferably, the classic controller is a PID controller or an active disturbance rejection controller; the modern controller is a sliding mode controller, an LQR controller, an explicit model controller, or an implicit model controller.

[0062] The design steps for a controller that combines classical and modern control principles are as follows:

[0063] (1) The error e is obtained by the controlled variable v0 and the output feedback variable y;

[0064] (2) The error e is converted into the classical control quantity u by the classical controller. e ;

[0065] (3) Modern controllers adjust the dynamic characteristics of the controlled object to obtain the modern control quantity u. x ;

[0066] (4) Classical control variable u e With modern control quantity u x The sums are used to obtain the total control quantity u;

[0067] (5) The total control quantity u is used as the input of the controlled object to obtain the output feedback quantity y;

[0068] (6) Repeat (1)-(5) until the output feedback quantity y is the same as the controlled quantity v0, then the controlled object reaches the expected response value.

[0069] The controller combining classical and modern control described in this embodiment is applied to a multi-input multi-output helicopter model. The controlled variables are collective pitch stick braking, cyclic pitch stick braking, and pedal braking; the output feedback variables are yaw rate, roll rate, and pitch rate, as detailed below:

[0070] Modern controllers use implicit model controllers, while classic controllers use PID controllers. The structure of an implicit model controller is as follows: Figure 6 As shown, the controller resulting from combining a PID controller and an implicit model controller is as follows: Figure 7 As shown.

[0071] Among them, Figure 6 In this equation, the inputs are represented by the control variations of collective pitch, lateral cyclic pitch, longitudinal cyclic pitch, and tail rotor pitch. A and B are the dynamic state matrix and control matrix in the helicopter system state equations, respectively. K is the state feedback matrix, and H is the feedforward compensation matrix. Figure 7 In order to be in Figure 6 A PID controller is added to the outer loop based on this.

[0072] like Figure 8 As shown, combining classical and modern control methods results in a faster response speed. Figure 9As shown in the figure, it can be seen that the combination of the classical control method and the modern control method is not sensitive to model errors. Among them, Figure 8 and Figure 9 The abscissa of each of the above figures is time.

[0073] Embodiment two

[0074] As Figure 10 shown, the classical control and modern control combined control method provided in this embodiment comprises:

[0075] Step 100: calculating an error value according to an input controlled quantity and an output feedback quantity;

[0076] Step 200: converting the error value into a classical control quantity based on an outer loop control strategy; the outer loop control strategy is a control strategy for eliminating errors based on errors;

[0077] Step 300: determining a controlled object control quantity according to the classical control quantity and an inner loop control strategy; the controlled object control quantity is an input of the controlled object, the output feedback quantity is an output of the controlled object; the inner loop control strategy is a control strategy of a control method based on internal mechanism description.

[0078] Further, step 300 specifically comprises:

[0079] determining a modern control quantity based on the inner loop control strategy and internal state information of the controlled object; determining the controlled object control quantity based on the classical control quantity and the modern control quantity.

[0080] Each of the embodiments in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0081] The principles and implementation manners of the present application are described by applying specific examples in this paper, and the above embodiment description is only used to help understand the method of the present application and its core idea; at the same time, for the general technical personnel in the field, according to the idea of the present application, the specific implementation manner and application range will be changed. In view of the above, the content of the specification should not be understood as the limitation of the present application.

Claims

1. A controller combining classical control and modern control, characterized by, The application relates to a controller combining classical control and modern control. The controller comprises an inner loop structure and an outer loop structure. The control strategy of the inner loop structure is a control strategy based on internal mechanism description, and the inner loop structure at least comprises: a modern controller connected in parallel with a controlled object, used for: determining a modern control quantity based on the control strategy of the inner loop structure and internal state information of the controlled object; and adjusting the dynamic characteristics of the controlled object based on the modern controller to obtain the modern control quantity; The control strategy of the outer loop structure is a control strategy based on error elimination, and the outer loop structure comprises: an error calculation unit used for calculating an error value according to an input controlled quantity and an output feedback quantity; a classical controller used for converting the error value into a classical control quantity based on an outer loop control strategy; the outer loop control strategy is a control strategy based on error elimination; determining a controlled object control quantity based on the classical control quantity and the modern control quantity; The inner loop structure is used for determining the controlled object control quantity according to the classical control quantity and an inner loop control strategy; the controlled object control quantity is the input of the controlled object, the output feedback quantity is the output of the controlled object, and the inner loop control strategy is a control strategy based on internal mechanism description; The controller combining classical control and modern control is applied to a multi-input multi-output helicopter model, the controlled quantity is total distance lever brake quantity, periodic variable distance lever brake quantity and foot pedal brake quantity, and the output feedback quantity is yaw angle speed, roll angle rate and pitch angle rate; The modern controller adopts a hidden model controller, and the classical controller adopts a PID controller; wherein the helicopter system state equation comprises a dynamic state matrix, a control matrix, a state feedback matrix and a feedforward compensation matrix; a PID controller is added to the outer loop based on the hidden model controller.

2. A control method combining classical control and modern control, characterized by, The application relates to a controller combining classical control and modern control. The classical controller is used for calculating an error value according to an input controlled quantity and an output feedback quantity; The error value is converted into a classical control quantity based on an outer loop control strategy; The outer loop control strategy is a control strategy based on error elimination; The controlled object control quantity is determined according to the classical control quantity and an inner loop control strategy, and specifically comprises: a modern control quantity is determined based on the inner loop control strategy and internal state information of the controlled object; the dynamic characteristics of the controlled object are adjusted based on a modern controller to obtain the modern control quantity; The controlled object control quantity is determined based on the classical control quantity and the modern control quantity; The controlled object control quantity is the input of the controlled object, the output feedback quantity is the output of the controlled object, and the inner loop control strategy is a control strategy based on internal mechanism description; The controller combining classical control and modern control is applied to a multi-input multi-output helicopter model, the controlled quantity is total distance lever brake quantity, periodic variable distance lever brake quantity and foot pedal brake quantity, and the output feedback quantity is yaw angle speed, roll angle rate and pitch angle rate; The modern controller adopts a hidden model controller, and the classical controller adopts a PID controller; wherein a helicopter system state equation comprises a dynamic state matrix, a control matrix, a state feedback matrix and a feedforward compensation matrix; a PID controller is added to the outer ring on the basis of the hidden model controller.

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