Equivalent input interference control method based on composite nonlinear feedback

Abstract

The invention provides an equivalent input interference control method based on composite nonlinear feedback, and the method comprises the steps: employing a full-dimensional state observer to estimate a system state value as a linear part in a composite nonlinear feedback device; the non-linear part adjusts the feedback intensity through an exponential non-linear function based on the system output and the reference input of the control object. The method comprises the steps that a state observer observes a control object to obtain a system state estimation value; the composite non-linear feedback device derives a feedback device output based on the reference input and the system state estimate. And the state feedback device obtains a state feedback item according to a state variable of the internal model controller, feedback device output and a system state estimated value. And the equivalent input disturbance compensator obtains a disturbance estimation value according to the state feedback item and the observer gain, and the disturbance estimation value serves as the compensation amount added to the input end of the control object. The fluctuation amplitude of system output when disturbance disappears and appears in a classical EID method is reduced, and meanwhile, the steady-state error of the system is also reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of interference control, and in particular to an equivalent input interference control method based on composite nonlinear feedback. Background Art

[0002] The Equivalent Input Disturbance (EID) method is a technique used in modern control theory to improve the anti-interference ability of a system. This method is mainly used to process interference signals that can be modeled as acting on the input of the system. The core idea of ​​the EID method is to estimate and offset these interferences by designing a specific controller or observer, so as to achieve the purpose of improving system performance. At present, the EID method has been successfully applied to permanent magnet synchronous motor systems, quad-rotor drone systems, etc., and has been widely used. However, when the system suddenly encounters a disturbance or the disturbance suddenly disappears, the disturbance error of the system will suddenly increase, causing the output of the system to fluctuate greatly. This sudden fluctuation of dynamic characteristics will reduce the transient performance of the system and increase the fluctuation time and overshoot of the system. When the system has input saturation characteristics or nonlinear characteristics, it may even cause system instability and control failure. Summary of the invention

[0003] The present invention provides an equivalent input disturbance control method based on composite nonlinear feedback, which is used to solve the defect of the classical EID method that the transient performance of the system will be reduced when the system suddenly encounters a disturbance or the disturbance suddenly disappears, and improve the transient characteristics of the EID method when the disturbance suddenly appears and disappears. The technical solution proposed by the present invention is as follows: In a first aspect, the present invention provides an equivalent input disturbance control method based on composite nonlinear feedback, which is applied to a control object, and the method comprises: Obtaining a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator; wherein the system state estimation value of the full-dimensional state observer is used as the linear part of the composite nonlinear feedback device, and the nonlinear part of the composite nonlinear feedback device adjusts the feedback intensity through an exponential nonlinear function based on the system output and reference input of the control object; The state observer observes the controlled object and obtains the estimated value of the system state; The compound nonlinear feedback device obtains a feedback device output based on a reference input and a system state estimation value; The state feedback device obtains a state feedback item according to the state variable of the internal model controller, the output of the feedback device and the estimated value of the system state; The equivalent input disturbance compensator obtains a disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and uses the disturbance estimation value as a compensation amount added to the input end of the control object.

[0004] Optionally, the state observer observes the controlled object to obtain a system state estimation value, including: Calculate the estimated value of the system output according to the previous estimated value of the system state and the system output matrix; Calculate the observation error based on the system output and the estimated value of the system output; The observation error is input into a pre-established state estimation equation, and the system state estimation value is updated through the state estimation equation.

[0005] Optionally, the observer gain is obtained in the following manner: Obtain each system matrix of the controlled object and construct a dual system according to the system matrix; Define the performance indicators of the dual system; Solving the Riccati equation minimizes the performance index of the dual system and obtains a positive definite symmetric matrix; Using the solved positive definite symmetric matrix, calculating the feedback control rate; Based on the feedback control rate, an observer gain is calculated.

[0006] Optionally, the composite nonlinear feedback device obtains a feedback device output based on a reference input and a system state estimation value, including: Calculate a first state error based on the system output and the reference input; Using the first state error as the input of the nonlinear function to obtain a nonlinear function result; Obtaining a solution to the Lyapunov equation, and calculating a nonlinear feedback term based on the nonlinear function result, the solution to the Lyapunov equation and the system state estimate; The linear output of the linear part of the composite nonlinear feedback device is obtained, and the nonlinear feedback term is superimposed on the linear output to obtain the feedback device output.

[0007] Optionally, the equivalent input disturbance compensator obtains a disturbance estimate according to the state feedback term and an observer gain of the full-dimensional state observer, comprising: Obtain the actual system state, system input matrix and system output matrix of the controlled object; Calculate the error between the actual state of the system and the estimated value of the system state to obtain a second state error; Calculate the pseudo-inverse matrix of the system input matrix; Acquire an actual control signal applied to an input terminal of a control object, and calculate a difference between the state feedback item and the actual control signal; A disturbance estimation value is calculated according to the pseudo-inverse matrix, the observer gain, the system output matrix, the second state error, and the difference between the state feedback term and the actual control signal.

[0008] Optionally, the method further comprises: The state feedback gain of the state observer is determined by using an optimal control method.

[0009] In a second aspect, the present invention further provides an equivalent input disturbance control device based on composite nonlinear feedback, comprising the following modules: An acquisition module is used to acquire a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator; wherein the system state estimation value of the full-dimensional state observer is used as the linear part of the composite nonlinear feedback device, and the nonlinear part of the composite nonlinear feedback device adjusts the feedback intensity through an exponential nonlinear function based on the system output and reference input of the control object; The observation module is used for the state observer to observe the control object and obtain the estimated value of the system state; A nonlinear feedback module, used for a compound nonlinear feedback device to obtain a feedback device output based on a reference input and a system state estimation value; A state feedback module, used for the state feedback device to obtain a state feedback item according to the state variable of the internal model controller, the output of the feedback device and the estimated value of the system state; The disturbance compensation module is used for the equivalent input disturbance compensator to calculate the disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and use the disturbance estimation value as the compensation amount added to the input end of the control object.

[0010] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the equivalent input disturbance control method based on composite nonlinear feedback as described in the first aspect above is implemented.

[0011] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the equivalent input disturbance control method based on composite nonlinear feedback as described in the first aspect above.

[0012] In a fifth aspect, the present invention further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the equivalent input disturbance control method based on composite nonlinear feedback as described in the first aspect above.

[0013] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows: The equivalent input disturbance control method based on composite nonlinear feedback provided by the present invention uses the estimated value of the system state by the observer as the linear part in the composite nonlinear feedback. This part can achieve the minimum energy of the system input and system state under the condition of no disturbance through the design of the optimal control algorithm. It also introduces nonlinear feedback. This part is based on the error between the system reference input and the system output, and designs an exponential nonlinear feedback term. When the system output approaches the reference input, the system damping is increased, and when the system output is far away from the reference signal, the system damping is reduced. The fluctuation amplitude of the system output when the disturbance disappears and appears in the classical EID method is reduced, and the steady-state error of the system is further reduced.

[0014] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural diagram of the classic equivalent input disturbance compensator.

[0018] Figure 2 It is a structural framework diagram of the equivalent input disturbance control system based on composite nonlinear feedback provided by the present invention.

[0019] Figure 3 It is a flow chart of the equivalent input disturbance control method based on composite nonlinear feedback provided by the present invention.

[0020] Figure 4 yes Figure 2 Equivalent transformation diagram of the system structure in .

[0021] Figure 5 It is a comparison chart of the control effects of the method of the present invention, traditional EID and high-order EID.

[0022] Figure 6It is a structural schematic diagram of an equivalent input disturbance control device based on composite nonlinear feedback provided by the present invention.

[0023] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] First, we analyze the problems existing in the classic EID method: Consider the linear system

[0026] (1)

[0027] in, is the system status; is the control input of the system; is the system output; is an unknown external disturbance; the system matrix in the system and is a known constant matrix of suitable dimension.

[0028] Assumption 1: Controllable and observable systems; Assumption 2: Perturbation is a bounded external disturbance that satisfies the condition

[0029] in, Is a positive number.

[0030] Classic EID methods such as Figure 1 According to the theory of EID method, an equivalent disturbance at the input can be defined as Therefore, (1) can be transformed into: (2)

[0031] For (2), design a full-dimensional state observer to estimate the state of the system: (3)

[0032] in, Is the system status The estimated value of is the state feedback term.

[0033] definition

[0034] (4)

[0035] Substituting (4) into (1) yields:

[0036] At this time, in order to obtain the estimated value of the equivalent disturbance at the input, She et al. made an assumption: (5)

[0037] Based on this assumption, the estimated value of the external disturbance of the system at the input is: (6)

[0038] Since the required input is estimated to be , and the actual disturbance estimate is The deviation between the two It will directly affect the disturbance suppression performance of the system and requires further compensation. It is an inevitable error in the classic EID method. This error will reduce the disturbance suppression capability of the EID method, and will also reduce the active noise reduction capability of the EID method. The reason for this error is that after the disturbance estimate in the EID method passes through the low-pass filter, the phase lag and replica attenuation caused by the frequency response are caused. Therefore, the frequency characteristics of the low-pass filter limit the disturbance suppression performance of the EID method.

[0039] When the system suddenly encounters a disturbance, or the disturbance suddenly disappears, It will suddenly become larger, which will cause the system output to fluctuate greatly. This sudden fluctuation of dynamic characteristics will reduce the transient performance of the system and increase the fluctuation time and overshoot of the system. When the system has input saturation characteristics or nonlinear characteristics, it may even cause system instability and control failure.

[0040] At present, there is little research on how to improve the transient performance of the EID method by scientific researchers, and there is no mature research result on how to improve the transient performance of the EID method. In order to improve the transient characteristics of the EID method when disturbances suddenly appear and disappear, that is, to reduce the fluctuation amplitude of the output of the EID control system when disturbances appear and disappear. The present invention proposes an equivalent input disturbance control method based on composite nonlinear feedback.

[0041] First, the present invention proposes an equivalent input disturbance control system based on composite nonlinear feedback. Figure 2The system is shown in Figure 1. The system includes an internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device, an equivalent input disturbance compensator and a control object.

[0042] Figure 2 middle, are the state variables of the internal model controller, is the internal model parameter in the internal model controller, is a low-pass filter, represents the order of the low-pass filter, is the state feedback gain, Represents a state feedback item.

[0043] (7)

[0044] The equivalent input interference control method based on compound nonlinear feedback provided by the present invention is implemented based on the above-mentioned equivalent input interference method control system based on compound nonlinear feedback.

[0045] This method can be applied to the above-mentioned control objects. Compared with the classic EID method, this application has two main differences: First, the system state estimate value of the full-dimensional state observer is used as the linear part in the composite nonlinear feedback device. This part is designed through the optimal control algorithm to achieve the minimum energy of the system input and system state in the absence of disturbance. Second, nonlinear feedback is introduced. The nonlinear part is based on the error between the system reference input and the system output, and an exponential nonlinear function is designed. The feedback intensity is adjusted by this nonlinear function. When the system output approaches the reference input, the system damping is increased, and when the system output is far away from the reference signal, the system damping is reduced. Refer to Figure 3 As shown, the method includes: Step S101, obtaining a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator.

[0046] Step S102: The state observer observes the controlled object to obtain an estimated value of the system state, which will serve as the basis for subsequent calculations.

[0047] First, the control object needs to be modeled to obtain its state space equation. Secondly, the structure and parameters of the state observer are designed according to the system model and control requirements. This includes determining the type of observer (such as full-dimensional or reduced-dimensional), selecting the observer gain of the observer, etc. The present invention selects a full-dimensional state observer for observation.

[0048] The full-dimensional state observer simulates the dynamic characteristics of the original system and introduces a feedback correction mechanism to obtain the state estimate. The feedback correction mechanism can adjust the observer's state estimate according to the system output error, thereby improving the accuracy of the estimate. The calculated system state estimate is output to the nonlinear feedback device and the state feedback device for state feedback control.

[0049] Step S103: The compound nonlinear feedback device obtains a feedback device output based on the reference input and the system state estimation value.

[0050] The compound nonlinear feedback controller calculates the feedback controller output based on the reference input (i.e., the desired system output) and the system state estimate through the internal linear and nonlinear parts. The linear part uses the system state estimate, while the nonlinear part adjusts the feedback intensity through a nonlinear function based on the system output and reference input of the control object to achieve precise control of system performance. The calculated feedback controller output is sent to the state feedback controller for state feedback control.

[0051] Step S104: The state feedback device obtains a state feedback item according to the state variable of the internal model controller, the output of the feedback device and the estimated value of the system state.

[0052] The state feedback device calculates the state feedback term based on the state variables of the internal model controller, the feedback device output and the estimated value of the system state. This feedback term will be used to adjust the control input of the system to achieve accurate control of the system state.

[0053] Step S105: the equivalent input disturbance compensator obtains a disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and uses the disturbance estimation value as a compensation amount added to the input end of the controlled object.

[0054] The equivalent input disturbance compensator calculates the disturbance estimate based on the state feedback term and the observer gain of the full-dimensional state observer. This disturbance estimate represents the impact of the external disturbance or internal uncertainty on the system state. The disturbance estimate is used as the compensation added to the input of the control object to offset the impact of external disturbance or internal uncertainty on the system, thereby improving the stability and performance of the system.

[0055] The nonlinear part of the above-mentioned composite nonlinear feedback device can be adjusted according to the nonlinear relationship between the system output and the reference input, thereby achieving precise control of the system performance. This adaptive capability enables the system to maintain stable performance output when facing different working conditions and disturbances, enhancing the robustness of the system. The combined effect of the internal model controller and the state feedback device can achieve precise control of the system state, and the introduction of the composite nonlinear feedback device further improves the response speed and accuracy of the system. The combined effect of these optimization measures can significantly improve the overall performance of the system. By introducing an equivalent input disturbance compensator, the external disturbance or internal uncertainty of the system can be estimated and compensated in real time, thereby effectively reducing the fluctuation and deviation of the system state and improving the stability of the system.

[0056] The equivalent input disturbance control method based on composite nonlinear feedback provided by the present invention uses the estimated value of the system state by the observer as the linear part in the composite nonlinear feedback. This part can achieve the minimum energy of the system input and system state under the condition of no disturbance through the design of the optimal control algorithm. It also introduces nonlinear feedback. This part is based on the error between the system reference input and the system output, and designs an exponential nonlinear feedback term. When the system output approaches the reference input, the system damping is increased, and when the system output is far away from the reference signal, the system damping is reduced. The fluctuation amplitude of the system output when the disturbance disappears and appears in the classical EID method is reduced, and the steady-state error of the system is further reduced.

[0057] In an optional embodiment, according to the mathematical model of the controlled object, a full-dimensional state observer of the system is established to estimate the state of the system. The state estimation equation is as follows: (8)

[0058] in, is the actual state of the system, The estimated value of the system state, is the state feedback term, is the observer gain, is the system output matrix, is the system output, is the system output The estimated value of .

[0059] The present invention uses an optimal control method to determine the state feedback gain of the state observer and The specific process is as follows: First, define the extended state vector

[0060] (9)

[0061] in, is the actual state of the system, are the state variables of the internal model controller.

[0062] as well as,

[0063] (10)

[0064] therefore

[0065] (11)

[0066] in,

[0067] ， ， (12)

[0068] because is an exogenous signal of equation (11), so the stability of equation (11) is related to The present invention adopts the linear quadratic regulator (LQR) method to design the state feedback gain , to stabilize the state feedback control system and improve its performance. Optimize performance indicators using optimal control algorithms : (13)

[0069] get (14)

[0070] in, and is the weight matrix, is a positive symmetric solution of the Riccati equation (15).

[0071] (15)

[0072] By minimizing the performance , it can ensure that the system has the desired behavior in both the actual state and the extended state. This helps to achieve a smoother and faster system response while reducing unnecessary control inputs. By considering the extended state vector, the additional dynamics of the system can be incorporated into the control design. This helps to enhance the robustness of the system to external disturbances or model uncertainties. Those skilled in the art can adjust the weight matrix according to specific application requirements. and .if If the design is larger, it means that we want the error value of the expansion state to be smaller in the steady state. A larger design means that you hope to control a smaller amount during the control process.

[0073] Based on the full-dimensional state observer designed above, the state observer described in step S102 observes the controlled object to obtain the estimated value of the system state, including: S1021, based on the estimated value of the previous system state And the system output matrix , using the second equation in the above state estimation equation, calculate the estimated value of the system output .

[0074] The previous system state estimate can be the previous state estimate of the system, or the initial state value obtained by other means (such as sensor measurement). The system output matrix is ​​an important parameter in the design of the state observer, which describes the relationship between the system state and the system output. Using the previous system state estimate and the system output matrix, the estimated value of the system output is calculated through matrix operations, and this estimated value will be compared with the actual system output.

[0075] S1022, according to the system output and an estimate of the system output , calculate the observation error, that is - .

[0076] The output of the system is obtained through sensors or other measurement devices. The system output is compared with the estimated value of the observer output to calculate the observation error. The observation error can be a scalar value (the overall error size) or a vector (the error of each state variable).

[0077] S1023, input the observation error into the first equation of the state estimation equation of the above formula (8), and update the system state estimation value through this equation . This equation combines the system dynamics ( ) and observation feedback ( ) to correct the state estimate.

[0078] The above state estimation equation is the core part of the state observer, which describes how to update the estimated value of the system state based on the previous state estimate, observation error and other related parameters. The observation error is input into the state estimation equation, and the estimated value of the system state is updated through the calculation of the equation. This new estimate will serve as the starting point for the next observation and will be used for subsequent control decisions.

[0079] In practical applications, the observation process of the state observer is iterative. The observer continuously receives new system output data, calculates the observation error, and updates the estimated value of the system state. This helps to track the changes in the system state in real time and provide accurate information for control decisions. According to the needs of practical applications and the changes in system states, the observer can be adjusted and optimized online. For example, the system output matrix, the parameters of the state estimation equation, etc. can be adjusted to improve the accuracy and robustness of the observer.

[0080] The present invention continuously receives the system output through the state observer, compares it with the estimated value of the system output, and calculates the observation error. This observation error is input into the pre-established state estimation equation in real time to update the system state estimation value. This real-time feedback and adjustment mechanism enables the system state estimation value to more accurately reflect the actual state of the system. In actual systems, due to factors such as model simplification, parameter changes or external disturbances, the system model often has errors. By continuously observing the system output and adjusting the state estimation value, the state observer can reduce the impact of these model errors on the system state estimation to a certain extent.

[0081] When the system is subject to external disturbances, the state observer can quickly detect such changes and reflect them by updating the state estimate. Even if there is noise or uncertainty in the system output, the state observer can still provide a relatively accurate state estimate and provide reliable feedback information for the compound nonlinear feedback device and the equivalent input disturbance compensator. This helps the equivalent input disturbance compensator to make timely adjustments to cope with external disturbances, thereby maintaining the stability of the system.

[0082] In an optional embodiment, the present application uses a linear quadratic programming algorithm (LQR) to design the observer gain of the above-mentioned full-dimensional state observer. The observer gain is obtained by: S201, obtain each system matrix of the control object, according to the system matrix Construct the dual system: (16)

[0083] in, is the state of the dual system.

[0084] First, it is necessary to clarify the mathematical model of the controlled object, which is usually in the form of state space, including the system state matrix A, the system output matrix B, and the system output matrix C. When designing a full-dimensional state observer, it is necessary to construct a dual system. The state matrix of this dual system is the state matrix of the original system. The transpose of ), and the output matrix is ​​the system output matrix of the original system The transpose of ).

[0085] S202. In LQR design, the performance index is a quadratic function of the system state and the control input. For the dual system, a similar performance index needs to be defined. This performance index will be used to guide the solution of the Riccati equation to find the optimal observer gain. The present invention defines the performance index of the dual system as as follows: (17)

[0086] in, and is the weight matrix, It is an adjustable parameter.

[0087] The corresponding Riccati equation can be constructed by using the defined performance index and the system matrix of the dual system. The Riccati equation constructed by the present invention is as follows: (18)

[0088] Solving this Riccati equation yields a positive definite symmetric matrix , this matrix is ​​the key to solving the observer gain.

[0089] S203, solving the Riccati equation so that the performance index of the dual system is minimized, and a positive definite symmetric matrix is ​​obtained. In MATLAB, the lyap function can be used to solve this equation.

[0090] S204. In LQR design, the feedback control rate indicates how to calculate the control input according to the current state of the system to achieve optimal control. The feedback control rate is calculated according to the following formula using the positive definite symmetric matrix obtained by solving: (19)

[0091] in, is the feedback control rate, and C is the system output matrix designed by the active noise reduction system according to the system status and requirements.

[0092] S205. According to the feedback control rate, the observer gain is calculated by the following formula: This gain matrix will be used to convert the observed output into an estimate of the system state.

[0093] (20)

[0094] By solving the Riccati equation, the present invention can obtain a positive symmetric matrix that minimizes the performance index of the dual system. This matrix is ​​further used to calculate the feedback control rate, thereby obtaining the gain of the observer. This gain calculation based on the optimization method can ensure that the observer reaches the optimal or near-optimal performance. Reasonable observer gain can reduce the estimation error of the system state, thereby reducing the oscillation of the system caused by the error. The optimization of the observer gain directly improves the estimation accuracy of the observer for the system state. Accurate observation results help the control system to understand the system state more accurately, thereby making more reasonable control decisions. Moreover, the optimization of the observer gain enables the observer to maintain good stability and robustness when facing uncertain factors such as system parameter changes and external disturbances. This helps the control system to maintain stable operation in a complex and changeable environment.

[0095] right Figure 2 By making an equivalent transformation of the system structure, we can obtain Figure 4 According to the system structure. Figure 4 , according to the separation theorem, the design of the system can be divided into two independent parts: 1) Design of the classic EID compensator (i.e. the part above the dotted line): The design of this part can be carried out according to the classic EID method; 2) Design of the system based on composite nonlinear feedback (i.e. the part below the dotted line): This part focuses on the design of the nonlinear feedback part.

[0096] According to the principle of composite nonlinear feedback, this application designs the nonlinear part control law of the equivalent input disturbance compensator The form is as follows: (twenty one)

[0097] in, Is a non-feedback output, and is a constant, is the system input matrix of the controlled object, is the estimated value of the system state, is the system output, is the reference input of the system, is a solution to the Lyapunov equation. It represents the deviation between the current state of the system and the expected state. is an exponential decay function, as the deviation It decreases as the value increases, and is used to adjust the amplitude of nonlinear feedback.

[0098] The Lyapunov equation is as follows: (twenty two)

[0099] in, and is the feedback gain, is a positive definite matrix.

[0100] The composite nonlinear feedback device described in step S103 obtains the feedback device output based on the reference input and the system state estimation value, including: S1031, according to the system output and reference input Calculate the first state error .

[0101] The composite nonlinear feedback device first receives the reference input and the estimated value of the system state. According to the difference between the actual output of the system and the reference input, the first state error is calculated. , which reflects the gap between the current state of the system and the expected state.

[0102] S1032: Using the first state error as the nonlinear function The nonlinear function is applied to the input to perform nonlinear transformation on the input, and the nonlinear function result is output. Approximation reference input When the nonlinear feedback amplitude increases, the system damping increases; when the system output Away from the reference signal When the nonlinear feedback amplitude decreases, the system damping is reduced. The intensity of feedback control can be adjusted through nonlinear characteristics to achieve fine adjustment of system performance.

[0103] S1033, obtaining a solution of the Lyapunov equation, which is used in the control system to analyze the stability of the system, and its solution provides information about the system state variables. Based on the nonlinear function result, the solution of the Lyapunov equation and the estimated value of the system state, a nonlinear feedback term is calculated. This step combines the characteristics of the system stability analysis and nonlinear feedback, and aims to generate a feedback control signal that can stabilize the system and improve performance.

[0104] S1034, obtaining the linear output of the linear part of the composite nonlinear feedback device, and superimposing the nonlinear feedback term on the linear output to obtain the feedback device output.

[0105] The linear output of the linear part of the composite nonlinear feedback device is obtained. The linear part calculates the output based on the system state estimate and the linear control law. The present invention sets the linear part in the composite nonlinear feedback device to The nonlinear feedback term is superimposed on the linear output to obtain the final feedback device output. The present invention combines linear control and nonlinear control to achieve comprehensive optimization of system performance.

[0106] By introducing nonlinear functions, the present invention enables the composite nonlinear feedback device to more flexibly adjust the intensity of feedback control, thereby achieving fine adjustment of system performance. This helps to improve the steady-state performance and transient performance of the system and improve the overall performance level of the system. The solution of the Lyapunov equation plays a key role in the design of the composite nonlinear feedback device. It provides information about the stability of the system and helps to design a feedback control strategy that can stabilize the system. Therefore, the composite nonlinear feedback device can enhance the stability of the system and reduce the risk of system instability. In addition, due to the introduction of nonlinear functions, the composite nonlinear feedback device can better cope with the uncertainty and nonlinear characteristics in the system and improve the robustness of the system. The composite nonlinear feedback device combines linear control and nonlinear control, and achieves comprehensive optimization of system performance through a simple structure. This helps to simplify the design process of the control system and reduce design costs and time costs.

[0107] In an optional embodiment, the present invention designs the EID compensator as follows: (twenty three)

[0108] in, is the perturbation estimate, The pseudo-inverse matrix of is the observer gain, is the system output matrix, is the actual state of the system, The estimated value of the system state, is the state feedback term, It is the actual control signal added to the input end of the controlled object.

[0109] The equivalent input disturbance compensator described in step S105 obtains a disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, including: S1051. Obtaining the actual system status of the control object , and the system input matrix describing the system dynamics and describes the relationship between system output and state .

[0110] S1052, calculation system actual status and system state estimate The error between the two states is the second state error, that is, the second state error .

[0111] S1053, using the above formula (7) to calculate the system input matrix The pseudo-inverse matrix .

[0112] S1054: Obtaining the actual control signal applied to the input end of the control object , calculate the state feedback term The actual control signal difference.

[0113] S1055, according to the pseudo inverse matrix , the observer gain , the system output matrix , the second state error , and the difference between the state feedback term and the actual control signal , use the above formula (23) to calculate the disturbance estimate.

[0114] The present invention estimates and compensates for disturbances in the system in real time, and the equivalent input disturbance compensator can significantly improve the robustness of the system, so that it can maintain stable performance under various working conditions. Since the disturbance can be accurately estimated and compensated, the state and output of the system can be controlled more accurately, thereby improving the control effect. By introducing a state observer and a feedback control mechanism, the equivalent input disturbance compensator can monitor and adjust the system state in real time, thereby effectively enhancing the stability of the system.

[0115] This method is applicable to various types of control objects and working conditions and has strong adaptability and flexibility.

[0116] Reference Figure 5 As shown, it is a comparison diagram of the control effect of the method of the present invention, the traditional EID and the high-order EID. Figure 5 From the waveform changes, it can be seen that the fluctuation of the system output of the method proposed by the present invention basically disappears at the moment when the disturbance is added and disappears, while the fluctuation of the traditional EID and high-order EID methods is obvious. In addition, the method proposed by the present invention also improves the tracking accuracy of the system output in the steady state.

[0117] The equivalent input disturbance control device based on compound nonlinear feedback provided by the present invention is described below. The equivalent input disturbance control device based on compound nonlinear feedback described below and the equivalent input disturbance control method based on compound nonlinear feedback described above can be referred to each other.

[0118] The equivalent input disturbance control device based on composite nonlinear feedback provided by the present invention refers to Figure 6 As shown, it includes the following modules: The acquisition module 301 is used to acquire a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator; wherein the system state estimation value of the full-dimensional state observer is used as the linear part of the composite nonlinear feedback device, and the nonlinear part of the composite nonlinear feedback device adjusts the feedback intensity through an exponential nonlinear function based on the system output and reference input of the control object; The state observation module 302 is used for the state observer to observe the control object and obtain the system state estimation value; A nonlinear feedback module 303, used for the composite nonlinear feedback device to obtain a feedback device output based on a reference input and a system state estimation value; A state feedback module 304, for a state feedback device to obtain a state feedback item according to a state variable of an internal model controller, an output of the feedback device and an estimated value of a system state; The disturbance compensation module 305 is used for the equivalent input disturbance compensator to calculate the disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and use the disturbance estimation value as the compensation amount added to the input end of the control object.

[0119] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communication interface 420 and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute the equivalent input disturbance control method based on compound nonlinear feedback.

[0120] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0121] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the equivalent input interference control method based on composite nonlinear feedback provided by the above methods.

[0122] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the equivalent input disturbance control method based on composite nonlinear feedback provided by the above methods.

[0123] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0124] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An equivalent input disturbance control method based on composite nonlinear feedback, applied to a control object, characterized in that: The method comprises: Obtaining a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator; wherein the system state estimation value of the full-dimensional state observer is used as the linear part of the composite nonlinear feedback device, and the nonlinear part of the composite nonlinear feedback device adjusts the feedback intensity through an exponential nonlinear function based on the system output and reference input of the control object; The state observer observes the controlled object and obtains the estimated value of the system state; The compound nonlinear feedback device obtains a feedback device output based on a reference input and a system state estimation value; The state feedback device obtains a state feedback item according to the state variable of the internal model controller, the output of the feedback device and the estimated value of the system state; The equivalent input disturbance compensator obtains a disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and uses the disturbance estimation value as a compensation amount added to the input end of the control object.

2. The equivalent input disturbance control method based on composite nonlinear feedback according to claim 1 is characterized in that: The state observer observes the controlled object to obtain a system state estimation value, including: Calculate the estimated value of the system output according to the previous estimated value of the system state and the system output matrix; Calculate the observation error based on the system output and the estimated value of the system output; The observation error is input into a pre-established state estimation equation, and the system state estimation value is updated through the state estimation equation.

3. The equivalent input disturbance control method based on composite nonlinear feedback according to claim 1 is characterized in that: The observer gain is obtained as follows: Obtain each system matrix of the controlled object and construct a dual system according to the system matrix; Define the performance indicators of the dual system; Solving the Riccati equation minimizes the performance index of the dual system and obtains a positive definite symmetric matrix; Using the solved positive definite symmetric matrix, calculating the feedback control rate; Based on the feedback control rate, an observer gain is calculated.

4. The equivalent input disturbance control method based on composite nonlinear feedback according to claim 1 is characterized in that: The composite nonlinear feedback device obtains a feedback device output based on a reference input and a system state estimation value, including: Calculate a first state error based on the system output and the reference input; Using the first state error as the input of the nonlinear function to obtain a nonlinear function result; Obtaining a solution to the Lyapunov equation, and calculating a nonlinear feedback term based on the nonlinear function result, the solution to the Lyapunov equation and the system state estimate; The linear output of the linear part of the composite nonlinear feedback device is obtained, and the nonlinear feedback term is superimposed on the linear output to obtain the feedback device output.

5. The equivalent input disturbance control method based on composite nonlinear feedback according to claim 1, characterized in that: The equivalent input disturbance compensator obtains a disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, including: Obtain the actual system state, system input matrix and system output matrix of the controlled object; Calculate the error between the actual state of the system and the estimated value of the system state to obtain a second state error; Calculate the pseudo-inverse matrix of the system input matrix; Acquire an actual control signal applied to an input terminal of a control object, and calculate a difference between the state feedback item and the actual control signal; A disturbance estimation value is calculated according to the pseudo-inverse matrix, the observer gain, the system output matrix, the second state error, and the difference between the state feedback term and the actual control signal.

6. The equivalent input disturbance control method based on composite nonlinear feedback according to claim 1, characterized in that: The method further comprises: The state feedback gain of the state observer is determined by using an optimal control method.

7. An equivalent input disturbance control device based on composite nonlinear feedback, applied to a control object, characterized in that: The device comprises: An acquisition module is used to acquire a pre-designed internal model controller, a state observer, a state feedback device, a composite nonlinear feedback device and an equivalent input disturbance compensator; wherein the system state estimation value of the full-dimensional state observer is used as the linear part of the composite nonlinear feedback device, and the nonlinear part of the composite nonlinear feedback device adjusts the feedback intensity through an exponential nonlinear function based on the system output and reference input of the control object; The observation module is used for the state observer to observe the control object and obtain the estimated value of the system state; A nonlinear feedback module, used for a compound nonlinear feedback device to obtain a feedback device output based on a reference input and a system state estimation value; A state feedback module, used for the state feedback device to obtain a state feedback item according to the state variable of the internal model controller, the output of the feedback device and the estimated value of the system state; The disturbance compensation module is used for the equivalent input disturbance compensator to calculate the disturbance estimation value according to the state feedback term and the observer gain of the full-dimensional state observer, and use the disturbance estimation value as the compensation amount added to the input end of the control object.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the equivalent input disturbance control method based on composite nonlinear feedback as claimed in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the equivalent input disturbance control method based on composite nonlinear feedback as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the equivalent input disturbance control method based on composite nonlinear feedback as claimed in any one of claims 1 to 6 is implemented.

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