High dynamic response anti-interference and noise suppression method and device for robot

Abstract

The invention belongs to the technical field of anti-interference, and discloses a high dynamic response anti-interference and noise suppression method and device for a robot, and the method comprises the steps: building an equivalent input interference state space model of a robot control system; designing a state observer, and obtaining a state observation value according to the system output of the robot control system and the state observer gain of the state observer; designing an internal model system, and establishing a state feedback controller of the robot control system according to the state observer and the internal model system; according to the method, a parallel-cascade interference estimator is designed, the parallel-cascade interference estimator comprises a plurality of equivalent input interference estimators and filters, the equivalent input interference estimators are connected in a mode of first parallel connection and then cascade connection, and a corresponding disturbance suppression feedback control law is designed. Through the combination of parallel connection and cascade connection, the disturbance estimation error is reduced, the disturbance suppression capability is enhanced, and the influence of measurement noise is remarkably reduced, so that the comprehensive performance of a robot control system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-interference, and in particular relates to a high dynamic response anti-interference and noise suppression method and device for a robot. Background Art

[0002] During the operation of the robot, factors such as changes in load inertia, uncertain external forces, and model uncertainty often cause system jitter, which seriously affects its operating stability and control accuracy. This jitter will not only reduce the robot's work efficiency, but may also lead to increased trajectory tracking errors and additional wear of the mechanical structure, thereby shortening the service life of the equipment. As a key technology in robot control, anti-interference technology is crucial to improving control accuracy. In addition, the impact of measurement noise on performance cannot be ignored. Excessive noise will significantly weaken the control performance of the system. Therefore, how to effectively suppress disturbances while reducing the impact of noise on the system has become a key issue in improving control accuracy and overall system performance, and has important practical significance for meeting the high-precision control requirements of robots.

[0003] At present, an effective solution is to regard factors such as load inertia change and external disturbance as the total disturbance of the system, and estimate and compensate them through disturbance estimation technology. In recent years, active anti-disturbance technology based on observers has been widely studied and applied, including disturbance observers, unknown input observers, extended state observers, and equivalent input disturbance (EID) methods. Among them, the method based on equivalent input disturbance has been successfully applied to various disturbance suppression scenarios because of its simple design and the absence of an inverse dynamics model or disturbance information model of the controlled object.

[0004] However, when there is measurement noise in the system, the performance of disturbance estimation based on the observer will inevitably be affected by the noise. In a closed-loop control system based on an equivalent input disturbance estimator, adjusting the observer gain can improve the disturbance rejection performance; a higher observer gain can improve the accuracy of disturbance rejection, but it will also amplify the noise. Therefore, the trade-off between disturbance rejection and noise attenuation becomes a key challenge in the design. Summary of the invention

[0005] The purpose of the present invention is to provide a high dynamic response anti-interference and noise suppression method and device for a robot. Through the combination of parallel and cascade, the estimator can not only effectively reduce the disturbance estimation error, but also significantly reduce the influence of measurement noise while enhancing the disturbance suppression capability, thereby improving the comprehensive performance of the robot control system.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a high dynamic response anti-interference and noise suppression method for a robot, which is applied to a robot control system. The high dynamic response anti-interference and noise suppression method for the robot comprises:

[0008] Establish an equivalent input-disturbance state-space model for the robot control system;

[0009] Designing a state observer according to the equivalent input disturbance state space model, and obtaining a state observation value according to a system output of the robot control system and a state observer gain of the state observer;

[0010] According to the equivalent input disturbance state space model, an internal model system is designed, and a state feedback controller of a robot control system is established according to the state observer and the internal model system, wherein the state feedback controller obtains a state feedback output according to the state of the internal model system and the state observation value;

[0011] Designing a parallel-cascade disturbance estimator, the parallel-cascade disturbance estimator comprising a plurality of equivalent input disturbance estimators and a filter, wherein the plurality of equivalent input disturbance estimators are connected in parallel first and then in cascade, and designing a corresponding disturbance suppression feedback control law;

[0012] Given a reference input of the robot control system, a control signal is obtained after passing through the endomembrane system and the state feedback controller. The control signal is used as the input of the parallel-cascade disturbance estimator, and the disturbance estimation output is obtained based on the disturbance suppression feedback control law. The disturbance estimation output and the equivalent input disturbance are used as the control input of the robot control system to obtain the output of the robot control system.

[0013] Preferably, the step of establishing an equivalent input disturbance state space model of the robot control system comprises:

[0014] Build a state-space model of the robot control system:

[0015]

[0016] Introduce equivalent input disturbance control and define for The equivalent input disturbance of the robot control system at time t, then the equivalent input disturbance state space model of the robot control system is established as:

[0017]

[0018] In the formula, yes The status of the robot control system at all times, Status The derivative of yes The control input of the robot control system at all times, yes The output of the robot control system at all times, yes The measurement noise of the robot control system at the moment, , , are the state matrix, input matrix and output matrix of the robot control system respectively. represents the external disturbance, is the gain matrix corresponding to the external disturbance.

[0019] Preferably, the state observer is designed as follows:

[0020]

[0021] In the formula, yes The status of the robot control system at all times The estimated value of , that is, the state observation value, For estimated value The derivative of yes Output of the robot control system The estimated value of yes The input of the state observer at each moment, is the state observer gain, , , They are the state matrix, input matrix and output matrix of the robot control system respectively.

[0022] Preferably, the inner mold system is designed as follows:

[0023]

[0024] In the formula, yes The state of the internal model system at time express The first-order differential of and is the system matrix with the same dimensions as the internal model system order, is the reference input of the robot control system, is the output of the robot control system.

[0025] Preferably, the equivalent input disturbance estimator is set Each equivalent input interference estimator is connected to a filter;

[0026] Pick Equivalent input disturbance estimators are connected in parallel, , get one or more parallel groups, and after parallel connection, connect the parallel groups and the remaining Equivalent input interference estimators are cascaded. When connected in parallel, multiple parallel groups are obtained.

[0027] Preferably, the disturbance suppression feedback control law is designed as follows:

[0028]

[0029]

[0030] In the formula, for The interference estimation output of the parallel-cascade interference estimator at time instant, is the control signal as input to the parallel-cascade disturbance estimator, represents the total value of disturbance estimation, Indicates The equivalent input disturbance estimator corresponds to the disturbance estimate filtered by the filter.

[0031] Preferably, the state feedback controller obtains the state feedback output according to the state and state observation value of the internal model system, including:

[0032]

[0033] in, for The state feedback output at each moment, for The state of the internal model system at time is the feedback gain of the state of the internal model system, yes The state observation value at time, is the feedback gain of the state observation value of the state observer.

[0034] Second aspect: The present invention provides a high dynamic response anti-interference and noise suppression device for a robot, comprising a processor and a memory storing a plurality of computer instructions, wherein the computer instructions, when executed by the processor, implement the steps of the high dynamic response anti-interference and noise suppression method for the robot.

[0035] In order to reduce the influence of load inertia change, external disturbance and other factors on motion control performance of robot control system during operation, and consider the interference of measurement noise on disturbance estimation accuracy and overall system performance, the present invention proposes a high dynamic response anti-interference and noise suppression method and device of robot based on equivalent input disturbance estimator. The method designs an equivalent input disturbance estimator with parallel-cascade variable structure, and its control architecture includes input signal internal model, state feedback controller, equivalent input disturbance controller and state observer. The equivalent input disturbance estimator accurately estimates the total disturbance of the system by combining parallel and cascade structures, and introduces the compensation signal of disturbance estimation into the control input of motion system, so as to realize active suppression of the total disturbance of the system. Through the combination of parallel and cascade, the estimator can not only effectively reduce the disturbance estimation error, but also significantly reduce the influence of measurement noise while enhancing the disturbance suppression capability, thereby improving the comprehensive performance of robot control system. The method of the present invention provides important technical support for high-precision control of robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of an embodiment of three equivalent input interference estimators provided by the present invention in parallel and cascade connection;

[0037] Figure 2 Based on Figure 1 A control block diagram of a robot's high dynamic response anti-interference and noise suppression method;

[0038] Figure 3 This is a comparison chart of system output results in the experiment of the present invention;

[0039] Figure 4 This is a disturbance estimation diagram for the comparative experiment in the experiment of the present invention;

[0040] Figure 5 This is a control block diagram of the present invention after structural simplification. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0043] Considering that the equivalent input disturbance estimator of the parallel structure can effectively improve the disturbance suppression effect of the system, and the equivalent input disturbance estimator of the cascade structure is helpful to reduce the influence of measurement noise. Therefore, this embodiment proposes a high dynamic response anti-interference and noise suppression method (PCEID) of a robot based on a parallel-cascade structure for the disturbance and measurement noise problems existing in the robot control system, which is of great significance for improving the control accuracy of the robot.

[0044] like Figure 1 and Figure 2 As shown, this embodiment provides a high dynamic response anti-interference and noise suppression method for a robot, which is applied to a robot control system and includes the following steps:

[0045] Step 1: Establish an equivalent input disturbance state space model of the robot control system.

[0046] First, construct the state space model of the robot control system as follows:

[0047]

[0048] Then, the equivalent input disturbance control is introduced, and the definition is for The equivalent input disturbance of the robot control system at time t, then the equivalent input disturbance state space model of the robot control system is established as:

[0049]

[0050] In the formula, yes The status of the robot control system at all times, Status The derivative of yes The control input of the robot control system at all times, yes The output of the robot control system at all times, yes The measurement noise of the robot control system at the moment, , , is the robot control system matrix that can be observed and controlled, which are the state matrix, input matrix and output matrix of the robot control system. represents the external disturbance, is the gain matrix corresponding to the external disturbance.

[0051] Step 2: Design a state observer according to the equivalent input disturbance state space model, and obtain a state observation value according to the system output of the robot control system and the state observer gain of the state observer.

[0052] This embodiment is described by taking three state observers and three parallel-cascade interference estimators (named EID1, EID2, and EID3, respectively, where EID1 and EID2 are connected in parallel and then cascaded with EID3) as an example. The state observer in this embodiment is designed as follows:

[0053]

[0054] In the formula, yes The status of the robot control system at all times The estimated value of , that is, the state observation value, where is the state observation value of state observer 1, is the state observation value of state observer 2, is the state observation value of state observer 3, For estimated value The derivative of yes Output of the robot control system The estimated value of Output pair for state observer 1 The estimated value of Two pairs of outputs for the state observer The estimated value of The state observer has three pairs of outputs The estimated value of yes The input of the state observer at the moment, where is the input of state observer 1 and state observer 2, is the input of state observer 3, is the state observer gain, where is the state observer gain of state observer 1, is the state observer gain of state observer 2, is the state observer gain of state observer 3.

[0055] Step 3: According to the equivalent input disturbance state space model, the internal model system is designed, and the state feedback controller of the robot control system is established according to the state observer and the internal model system. The state feedback controller obtains the state feedback output according to the state and state observation value of the internal model system.

[0056] The inner mold system of this embodiment is designed as follows:

[0057]

[0058] In the formula, yes The state of the internal model system at time express The first-order differential of and is the system matrix with the same dimensions as the internal model system order, is the reference input of the robot control system, is the output of the robot control system.

[0059] And the state feedback controller is designed as follows:

[0060]

[0061] in, for The state feedback output at each moment, for The state of the internal model system at time is the feedback gain of the state of the internal model system, yes The state observation value at time, is the feedback gain of the state observation value of the state observer.

[0062] Step 4: Design a parallel-cascade interference estimator. The parallel-cascade interference estimator includes multiple equivalent input interference estimators and filters. The multiple equivalent input interference estimators are connected in parallel first and then in cascade to improve the overall disturbance estimation accuracy, and design the corresponding disturbance suppression feedback control law.

[0063] The equivalent input interference estimator used in this embodiment is as follows:

[0064]

[0065] The filters used are as follows:

[0066]

[0067] In the formula, yes Equivalent input disturbance of robot control system at any moment The estimated value of The equivalent input disturbance estimator in EID1 is used to calculate the equivalent input disturbance The estimated value of The equivalent input disturbance estimator in EID2 is used to calculate the equivalent input disturbance The estimated value of The equivalent input disturbance estimator in EID3 is used to calculate the equivalent input disturbance The estimated value of yes The generalized inverse of yes The transpose of It contains three first-order low-pass filters, corresponding to three-level equivalent input disturbance control. Indicates A parallel-cascade interference estimator ( ), Representation filter The time constant, Indicates the s domain.

[0068] Set the equivalent input disturbance estimator settings in the parallel-cascade disturbance estimator indivual, , each equivalent input interference estimator is connected to a filter, and the parallel and cascade connection is as follows:

[0069] Pick Equivalent input disturbance estimators are connected in parallel, , get one or more parallel groups, and after parallel connection, connect the parallel groups and the remaining Equivalent input interference estimators are cascaded. When connected in parallel, multiple parallel groups are obtained.

[0070] when When , two equivalent input interference estimators are connected in parallel and then cascaded with the remaining equivalent input interference estimator; when ,and When , it means that all equivalent input disturbance estimators are connected in parallel. Therefore, in order to ensure the existence of the cascade structure, multiple parallel groups need to be connected in parallel. For example, the equivalent input disturbance estimator ABCD can be connected in parallel with AB to obtain a parallel group, and then CD can be connected in parallel to obtain a parallel group, and the two parallel groups are cascaded. When ,and When , it indicates that there are equivalent input interference estimators remaining that are only used for cascading. At this time, the equivalent input interference estimators participating in parallel can be connected in parallel as one parallel group, or in parallel as multiple parallel groups, and then cascaded with the equivalent input interference estimators that are only used for cascading. It should be noted that the parallel connection of the equivalent input interference estimators and the selection of the cascade structure are determined according to the actual design scenario and are not limited in this embodiment.

[0071] For The parallel-cascade disturbance estimator composed of equivalent input disturbance estimators is designed with the disturbance rejection feedback control law as follows:

[0072]

[0073]

[0074] In the formula, for The interference estimation output of the parallel-cascade interference estimator at time instant, is the control signal as input to the parallel-cascade disturbance estimator, represents the total value of disturbance estimation, Indicates The equivalent input disturbance estimator corresponds to the disturbance estimate filtered by the filter.

[0075] For ease of understanding, this embodiment takes three parallel-cascade interference estimators (named EID1, EID2, and EID3, respectively, where EID1 and EID2 are connected in parallel and then cascaded with EID3) as an example for explanation. The outputs of the three EIDs in the parallel-cascade interference estimator are , and , represents the sum disturbance estimate of the output of the three equivalent input disturbance estimators , and The filtered disturbance estimate, It is expressed as follows:

[0076]

[0077] In the formula, and They represent the disturbance estimates and the total disturbance estimate The S transform.

[0078] And design the corresponding disturbance suppression feedback control law. According to the above parallel-cascade disturbance estimator mechanism, design the corresponding disturbance suppression feedback control law. The specific formula is as follows:

[0079]

[0080] In the formula, Represents the system control input of the robot control system, i.e., the state feedback controller The state feedback output at each moment, represents the output of the parallel-cascade interference estimator.

[0081] Step 5: Given the reference input of the robot control system , reference input After passing through the endomembrane system and the state feedback controller, the control signal is obtained , the control signal As the input of the parallel-cascade disturbance estimator, the disturbance estimation output is obtained based on the disturbance rejection feedback control law. , the interference estimate is output and equivalent input interference As the control input of the robot control system, the output of the robot control system is obtained .

[0082] The method of this embodiment is used to conduct a comparative experiment in the fixed-point control system of the robot arm. The experimental output results are as follows: Figure 3 As shown, Figure 3 The horizontal axis is time Time, the unit is second s, and the vertical axis is the output y of the robot arm fixed-point control system, the unit is millimeter mm. Figure 3 PCEID is the output result of this method. The other three EIDs, Cascade EID (CEID) and Parallel-Cascade Extend-State-Observer (PCESO) are experimental comparison objects under the same conditions. It can be obviously seen that the method of the present invention has greatly improved the anti-interference performance of the robot arm fixed-point control system. The output result error is only ±0.02mm, while the best output result error of other anti-interference methods also reaches ±0.03mm.

[0083] Figure 4 is a comparative experimental disturbance estimation diagram of the method of the present invention in a fixed-point control system of a manipulator. Figure 4 The horizontal axis is the time Time, in seconds, and the vertical axis is the noise of the disturbance estimate. , the unit is speed / minute rpm. It can be clearly seen that this method has no significant effect on the measurement noise. Better suppression effect, no obvious noise phenomenon in disturbance estimation.

[0084] Embodiment 2: Based on Embodiment 1, this embodiment further simplifies the structure and provides a high dynamic response anti-interference and noise suppression method for a robot, such as Figure 5 As shown, the following steps are included:

[0085] S101, construct two equivalent input interference estimators EID1 and EID2, connect EID1 and EID2 in parallel, and their input signals are: and , its output signal is: .

[0086] S102, construct an equivalent input interference estimator EID3, cascade EID3 with the parallel EID1 and EID2, and its input signal is the output of the above parallel structure: and , its output signal is: , and finally the output signal will be and the equivalent disturbance signal As input to the robot control system, the output . So far, the structural construction of the parallel-cascade equivalent input interference estimator is completed.

[0087] S201, based on the above structure, the state observer gain in the state observer in the parallel group and Set to the same value to get a new , the observers of EID1 and EID2 are exactly the same, so they are simplified to a common part: state observer 1. And the observer parameters of EID3 are The new setting is , that is, state observer 2 is obtained.

[0088] S202, based on the simplified parallel-cascade interference estimator structure, the reference input of the system is , Output from the robot control system The difference is formed into a negative feedback system, and then the basic control of the system is completed through the controller composed of the internal model and state feedback, and the control signal is output The parallel-cascade interference estimator then As input, output As the equivalent perturbation Finally, the compensated signal is input into the robot control system to obtain the output .in represents the measurement noise of the robot control system.

[0089] Embodiment 3: This embodiment provides a high dynamic response anti-interference and noise suppression device for a robot, comprising a processor and a memory storing a plurality of computer instructions, wherein the computer instructions, when executed by the processor, implement the steps of the high dynamic response anti-interference and noise suppression method for the robot.

[0090] For the specific definition of the robot's high dynamic response anti-interference and noise suppression device, please refer to the definition of the robot's high dynamic response anti-interference and noise suppression method above, which will not be repeated here.

[0091] The memory and the processor are electrically connected directly or indirectly to achieve data transmission or interaction. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The memory stores a computer program that can be run on the processor, and the processor implements the method of the present invention by running the computer program stored in the memory.

[0092] The memory may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc. The memory is used to store a program, and the processor executes the program after receiving an execution instruction.

[0093] The processor may be an integrated circuit chip with data processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0094] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A high dynamic response anti-interference and noise suppression method for a robot, applied to a robot control system, characterized in that: The high dynamic response anti-interference and noise suppression method of the robot comprises: Establish an equivalent input-disturbance state-space model of the robot control system; Designing a state observer according to the equivalent input disturbance state space model, and obtaining a state observation value according to a system output of the robot control system and a state observer gain of the state observer; According to the equivalent input disturbance state space model, an internal model system is designed, and a state feedback controller of a robot control system is established according to the state observer and the internal model system, wherein the state feedback controller obtains a state feedback output according to the state of the internal model system and the state observation value; Designing a parallel-cascade disturbance estimator, the parallel-cascade disturbance estimator comprising a plurality of equivalent input disturbance estimators and a filter, wherein the plurality of equivalent input disturbance estimators are connected in parallel first and then in cascade, and designing a corresponding disturbance suppression feedback control law; Given a reference input of the robot control system, a control signal is obtained after passing through the endomembrane system and the state feedback controller. The control signal is used as the input of the parallel-cascade disturbance estimator, and the disturbance estimation output is obtained based on the disturbance suppression feedback control law. The disturbance estimation output and the equivalent input disturbance are used as the control input of the robot control system to obtain the output of the robot control system.

2. The high dynamic response anti-interference and noise suppression method of the robot according to claim 1, characterized in that: The establishing of an equivalent input disturbance state space model of the robot control system comprises: Build a state-space model of the robot control system: ； Introducing equivalent input disturbance control, define for The equivalent input disturbance of the robot control system at time t, then the equivalent input disturbance state space model of the robot control system is established as: ； In the formula, yes The status of the robot control system at all times, Status The derivative of yes The control input of the robot control system at all times, yes The output of the robot control system at all times, yes The measurement noise of the robot control system at the moment, , , are the state matrix, input matrix and output matrix of the robot control system respectively. represents the external disturbance, is the gain matrix corresponding to the external disturbance.

3. The high dynamic response anti-interference and noise suppression method of the robot according to claim 1, characterized in that: The state observer is designed as follows: ； In the formula, yes The status of the robot control system at all times The estimated value of , that is, the state observation value, For estimated value The derivative of yes Output of the robot control system The estimated value of yes The input of the state observer at each moment, is the state observer gain, , , They are the state matrix, input matrix and output matrix of the robot control system respectively.

4. The high dynamic response anti-interference and noise suppression method of a robot according to claim 1, characterized in that: The inner mold system is designed as follows: ； In the formula, yes The state of the internal model system at time express The first-order differential of and is the system matrix with the same dimensions as the internal model system order, is the reference input of the robot control system, is the output of the robot control system.

5. The high dynamic response anti-interference and noise suppression method of a robot according to claim 1, characterized in that: The equivalent input disturbance estimator is set Each equivalent input interference estimator is connected to a filter; Pick Equivalent input disturbance estimators are connected in parallel, , get one or more parallel groups, and after parallel connection, connect the parallel groups and the remaining Equivalent input interference estimators are cascaded. When connected in parallel, multiple parallel groups are obtained.

6. The high dynamic response anti-interference and noise suppression method of a robot according to claim 5, characterized in that: The disturbance rejection feedback control law is designed as follows: ； ； In the formula, for The interference estimation output of the parallel-cascade interference estimator at time instant, is the control signal as input to the parallel-cascade disturbance estimator, represents the total value of disturbance estimation, Indicates The equivalent input disturbance estimator corresponds to the disturbance estimate filtered by the filter.

7. The high dynamic response anti-interference and noise suppression method of a robot according to claim 1, characterized in that: The state feedback controller obtains a state feedback output according to the state and state observation value of the internal model system, including: ； in, for The state feedback output at each moment, for The state of the internal model system at time is the feedback gain of the state of the internal model system, yes The state observation value at time, is the feedback gain of the state observation value of the state observer.

8. A high dynamic response anti-interference and noise suppression device for a robot, comprising a processor and a memory storing a plurality of computer instructions, characterized in that: When the computer instructions are executed by the processor, the steps of the high dynamic response anti-interference and noise suppression method of the robot described in any one of claims 1 to 7 are implemented.

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