A dynamic compensation control method and device for an indirect measurement servo system

Abstract

This application discloses a dynamic compensation control method and apparatus for an indirect measurement servo system. The method includes: inputting an initial load torque into a first dynamic model, whereby the first dynamic model calculates a torque estimate, a position estimate, and a position sensor measurement value of an intermediate feedback mechanism based on the initial load torque; using the torque estimate, position estimate, and position sensor measurement value of the intermediate feedback mechanism as inputs to an output torque observation model of the intermediate feedback mechanism to obtain a structural output force at the observed sensing position; using the position sensor measurement value of the intermediate feedback mechanism as inputs to an end-effector acceleration estimation model to obtain an end-effector acceleration; using the structural output force and end-effector acceleration at the observed sensing position as inputs to a second dynamic model to calculate an estimated end-effector load torque; and calculating the estimated end-effector load torque based on the estimated end-effector load torque and the load. This application solves the technical problem in the prior art where indirect measurement servo systems cannot meet practical needs.

Description

Technical Field

[0001] This application relates to the field of special environment servo technology, and in particular to a dynamic compensation control method and device for an indirect measurement servo system. Background Technology

[0002] In the field of aerospace servo systems, such as high-speed aircraft actuators and space mechanisms, due to harsh environments such as high and low temperatures and impacts, sensors cannot be directly placed at the end of the actuator (nozzle, control surface, etc.). They can only be placed in intermediate feedback mechanisms, and the position of the control end is approximated through indirect measurement methods. With the development of guidance and control technology, the traditional method of directly using indirect measurement feedback as the measurement method for the end position is gradually becoming unsuitable for new control requirements such as high bandwidth, large aspect ratio projectiles, and high-precision attitude. On the one hand, due to the strict limitations on the weight and volume of the projectile, the stiffness of the transmission structure cannot be made very high; on the other hand, due to limitations such as manufacturing errors and assembly precision, there are unavoidable gaps inside the control transmission mechanism, which have an adverse effect on the dynamic characteristics of the mechanism. When the end is subjected to time-varying load torque, or when the end follower is in a high dynamic response state, the transmission mechanism undergoes dynamic displacement and deformation due to uncertain and time-varying disturbance forces, making the intermediate structure unable to reflect the true end position, resulting in control errors. Under the action of high dynamic forces, the position of the intermediate feedback mechanism and the end has lag and error. In severe cases, it couples with attitude control to produce projectile chattering, leading to flight failure.

[0003] To address the high-dynamic, high-precision control challenges of indirect measurement systems such as high-speed aircraft, existing load observation techniques can be broadly categorized into two types: one treats the servo system as a rigid whole, estimating the external load through the motor's electromagnetic torque. For example, Chinese patent CN108429501A discloses a method for observing load disturbances in a permanent magnet synchronous motor, estimating the load torque using motor speed and current. This method is only suitable for high-rigidity systems and requires high linearity from the motor itself; otherwise, under motor torque fluctuations and high-dynamic reciprocating motion, the observation errors of the motor's electromagnetic torque and rotor acceleration are large, easily leading to limit cycle oscillations and poor stability. The other method observes the external load by combining the motor's electromagnetic torque and end-effector acceleration. This method requires real-time acquisition of the end-effector position, which does not meet the requirements for use under indirect measurement conditions. Summary of the Invention

[0004] The technical problem solved by this application is that existing indirect measurement servo systems cannot meet practical needs. This application provides a dynamic compensation control method and device for indirect measurement servo systems. In the solution provided by the embodiments of this application, the load torque is observed in real time without force feedback at the end, compensating for the influence of load disturbances. The observed torque has high accuracy, good stability, and low delay. Furthermore, in the absence of sensor feedback at the end, the end acceleration is estimated using the observed intermediate torque, achieving high dynamic and high-precision control of the end.

[0005] In a first aspect, embodiments of this application provide a dynamic compensation control method for an indirect measurement servo system. The method includes: constructing a simulation model of the indirect measurement servo system, wherein the simulation model includes a first dynamic model of the motor and intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end-effector acceleration estimation model, a second dynamic model of the end-effector structure, and a load torque compensation model; inputting an initial load torque into the first dynamic model, wherein the first dynamic model calculates a torque estimate, a position estimate, and a position sensing measurement value of the intermediate feedback mechanism based on the initial load torque; using the torque estimate, position estimate, and position sensing measurement value of the intermediate feedback mechanism as inputs to the output torque observation model of the intermediate feedback mechanism to obtain a structural output force at the observed sensing position; using the position sensing measurement value of the intermediate feedback mechanism as inputs to the end-effector acceleration estimation model to obtain an end-effector acceleration; using the structural output force at the observed sensing position and the end-effector acceleration as inputs to the second dynamic model to calculate an estimated end-effector load torque; calculating a compensation value based on the estimated end-effector load torque and the load torque compensation model, and compensating for the initial load torque based on the compensation value.

[0006] Optionally, the first dynamic model is:

[0007]

[0008]

[0009] Where x1 and x2 represent state variables; θ0 is the rotor stroke of the motor; θ1 is the position sensor measurement value of the intermediate feedback mechanism; J0 is the moment of inertia of the motor rotor in the direction of motion; J1 is the equivalent moment of inertia of the motor and the intermediate feedback mechanism in the direction of motion; h 01 This is the transmission ratio from the motor rotor to the intermediate feedback mechanism.

[0010] Optionally, the output torque observation model of the intermediate feedback mechanism is:

[0011]

[0012] in, These are the estimated values ​​of state variables x1, x2, and redundant state variable x3, respectively, where x3 = τ1, τ1 is the combined load torque of the terminal to the intermediate feedback mechanism and the unmodeled error disturbance; τ m q is the electromagnetic torque input of the motor; p is the tracking compensator gain; g(x1,x2) is the nonlinear error fitting term; q is the estimator gain.

[0013] Optionally, the terminal acceleration estimation model is:

[0014]

[0015] Among them, G 1L (s) represents the terminal acceleration estimation model, where s denotes the complex frequency; J L h is the terminal moment of inertia. 1L k is the transmission ratio from the intermediate feedback mechanism to the end effector. 1L D represents the equivalent stiffness coefficient from the intermediate feedback mechanism to the end effector. 1L G represents the equivalent damping coefficient from the intermediate feedback mechanism to the end effector. F1 (s) is a conventional low-pass filter.

[0016] Optionally, the second dynamic model is:

[0017]

[0018] in, This is an estimate of the load torque applied to the end. The structural output force for observing the sensing position; J L It is the terminal moment of inertia; This refers to the terminal acceleration.

[0019] Optionally, the load torque compensation model is:

[0020]

[0021] Where, Δθ d This is the load torque compensation value; for Positively correlated odd functions.

[0022] Secondly, embodiments of this application provide a dynamic compensation control device for an indirect measurement servo system, the device comprising:

[0023] The modeling unit is used to construct a simulation model of the indirect measurement servo system. The simulation model includes a first dynamic model of the motor and intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end-effector acceleration estimation model, a second dynamic model of the end-effector structure, and a load torque compensation model.

[0024] The first calculation unit is used to input the initial load torque into the first dynamic model, and the first dynamic model calculates the torque estimate, position estimate and position sensing measurement value of the intermediate feedback mechanism based on the initial load torque.

[0025] The estimation unit is used to take the torque estimate, position estimate, and position sensing measurement value of the intermediate feedback mechanism as inputs to the output torque observation model of the intermediate feedback mechanism to obtain the structural output force at the observed sensing position; and to take the position sensing measurement value of the intermediate feedback mechanism as inputs to the end acceleration estimation model to obtain the end acceleration;

[0026] The second calculation unit uses the structural output force at the observed sensing position and the end acceleration as inputs to the second dynamic model to calculate the estimated value of the end load torque.

[0027] The compensation unit is used to calculate a compensation value based on the estimated end load torque and the load torque compensation model, and to compensate the initial load torque based on the compensation value.

[0028] Thirdly, this application provides a computer device, the computer device comprising:

[0029] Memory, used to store at least one instruction executed by a processor;

[0030] A processor is configured to execute instructions stored in memory to perform the method described in the first aspect.

[0031] Fourthly, this application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform the method described in the first aspect.

[0032] Compared with the prior art, the solution provided in this application has at least the following beneficial effects:

[0033] The solution provided in this application's embodiments observes the load torque in real time even without force feedback at the end point, compensating for the effects of load disturbances. The observed torque exhibits high accuracy, good stability, and low latency. Furthermore, even without sensor feedback at the end point, the observed intermediate torque is used to estimate the end-point acceleration, achieving high dynamic and high-precision control of the end point. Attached Figure Description

[0034] Figure 1 A flowchart illustrating a dynamic compensation control method for an indirect measurement servo system provided in an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the structure of a simulation model of an indirect measurement servo system provided in an embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the servo system provided in the embodiments of this application;

[0037] Figure 4 A is a schematic diagram of the nozzle attitude under load force and push rod feedback under conventional control method;

[0038] Figure 4 B is a schematic diagram of the nozzle attitude under load force and push rod feedback result provided in the embodiment of this application with the introduction of dynamic load compensation control;

[0039] Figure 5 This is a schematic diagram of the structure of a dynamic compensation control device for an indirect measurement servo system provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0041] The embodiments described in this application are only a part of the embodiments, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0043] The following description, in conjunction with the accompanying drawings, provides a more detailed explanation of a dynamic compensation control method for an indirect measurement servo system provided in this application. The specific implementation of this method may include the following steps (method flow as follows): Figure 1 As shown):

[0044] Step 101: Construct a simulation model of the indirect measurement servo system. The simulation model includes a first dynamic model of the motor and intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end-effector acceleration estimation model, a second dynamic model of the end-effector structure, and a load torque compensation model.

[0045] Step 102: Input the initial load torque into the first dynamic model. The first dynamic model calculates the torque estimate, position estimate, and position sensing measurement value of the intermediate feedback mechanism based on the initial load torque.

[0046] Step 103: The estimated torque value, the estimated position value, and the position sensing measurement value of the intermediate feedback mechanism are used as inputs to the output torque observation model of the intermediate feedback mechanism to obtain the structural output force at the observed sensing position; and the position sensing measurement value of the intermediate feedback mechanism is used as inputs to the end acceleration estimation model to obtain the end acceleration.

[0047] Step 104: The structural output force at the observed sensing position and the end acceleration are used as inputs to the second dynamic model to calculate the estimated end load torque.

[0048] Step 105: Calculate the compensation value based on the estimated end load torque and the load torque compensation model, and compensate the initial load torque based on the compensation value.

[0049] Figure 2 A schematic diagram of a simulation model of an indirect measurement servo system provided in an embodiment of this application is shown.

[0050] For example, such as Figure 2 As shown, the simulation model of the indirect measurement servo system includes a first dynamic model of the motor and intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end-effector acceleration estimation model, a second dynamic model of the end-effector structure, and a load torque compensation model. Among them, the output of the first dynamic model is used as the input of the output torque observation model and the end-effector acceleration estimation model of the intermediate feedback mechanism, the output of the output torque observation model and the end-effector acceleration estimation model of the intermediate feedback mechanism is used as the input of the second dynamic model, and the output of the second dynamic model is used as the input of the load torque compensation model.

[0051] Figure 3 A schematic diagram of the servo system is shown.

[0052] For example, such as Figure 3As shown, the servo system's sensors are arranged in the intermediate feedback mechanism. Due to the extremely high temperatures (hundreds of degrees Celsius) on the control surface (the control end), the sensors cannot be placed on the control shaft and must be placed on the ball screw, thus creating a servo system based on indirect measurement. In the solution provided in this application embodiment, a 2-DOF dynamic model is established based on the sensor arrangement range. Specifically, since the end position cannot be measured, this dynamic model establishes the reaction force of the end structure as an external force of the system.

[0053]

[0054] Where θ0 is the rotor travel of the motor, which can be obtained by a sensor at the motor end or by existing rotor position estimation methods; θ1 is the position sensor measurement value of the intermediate feedback mechanism; J0 is the moment of inertia of the motor rotor in the direction of motion; J1 is the equivalent moment of inertia of the motor and the intermediate feedback mechanism in the direction of motion; h 01 τ represents the transmission ratio from the motor rotor to the intermediate feedback mechanism. m The electromagnetic torque input for the motor can be obtained using mature technologies such as current value estimation; τ0 is the motor output torque; and τ1 is the torque of the intermediate feedback mechanism.

[0055] Simplifying equation (1) to eliminate τ0, we obtain the overall dynamic model as follows:

[0056]

[0057] The state variables are selected as follows:

[0058]

[0059]

[0060] Where x1 and x2 represent state variables; if no sensors are configured at the motor end or intermediate structure, then θ0 = h 01 θ1.

[0061] The state equation of the motor-intermediate feedback mechanism system is:

[0062]

[0063] Where, τ m The electromagnetic torque input of the motor can be obtained using mature technologies such as current estimation; τ1 is the combined load torque of the end to the intermediate feedback mechanism and the unmodeled error disturbance.

[0064] Furthermore, τ1 in formula (3) is expanded to a redundant state x3, i.e., x3 = τ1, and it is assumed that x3 has a continuous first derivative; based on the expanded state, the output torque observation model of the intermediate feedback mechanism is configured as follows:

[0065]

[0066] in, These are the estimated values ​​of state variables x1, x2, and redundant state variable x3, respectively, where x3 = τ1, τ1 is the combined load torque of the terminal to the intermediate feedback mechanism and the unmodeled error disturbance; τ m q is the electromagnetic torque input of the motor; p is the tracking compensator gain; g(x1,x2) is the nonlinear error fitting term; q is the estimator gain.

[0067] For g(x1,x2), it can be obtained through a priori model plus experimentation. For example, for a system with Coulomb friction, it can be defined as follows:

[0068]

[0069] Where, τ sf Let B be the Coulomb friction force, and B be the viscous friction coefficient.

[0070] System output y ESO The estimated value of redundant state x3, i.e. Thus, the force exerted on the end structure from the intermediate feedback mechanism can be obtained using an observer method. However, to obtain the external load torque, the motion acceleration information of the end structure is also required.

[0071] Since there are no sensors, the end-effector position can only be estimated based on the position of the intermediate feedback mechanism. Typically, to ensure control accuracy, the structural stiffness from the intermediate feedback mechanism to the end-effector is as high as possible, and its force transmission bandwidth is much larger than the bandwidth of external load changes. During high-dynamic motion, changes in the external load are ignored, and the external load can be considered a constant force. The interaction between the intermediate feedback mechanism and the end-effector structure can be simplified to a spring-damped structure:

[0072]

[0073] Taking the Laplace transform, we get:

[0074]

[0075] Ignoring the influence of the integral term instantaneously, we obtain the end-effector acceleration estimation model from the angle of the intermediate feedback mechanism to the end-effector acceleration:

[0076]

[0077] The transfer function contains a pure differential term, which can easily amplify signal noise. Therefore, an additional low-pass filter is configured to reduce the impact of noise.

[0078]

[0079]

[0080] Among them, G 1L (s) represents the terminal acceleration estimation model, where s denotes the complex frequency; J L h is the terminal moment of inertia. 1L k is the transmission ratio from the intermediate feedback mechanism to the end effector. 1L D represents the equivalent stiffness coefficient from the intermediate feedback mechanism to the end effector. 1L G represents the equivalent damping coefficient from the intermediate feedback mechanism to the end effector. F1 (s) is a conventional low-pass filter.

[0081] Furthermore, in the solution provided in the embodiments of this application, the second dynamic model is:

[0082]

[0083] in, This is an estimate of the load torque applied to the end. The structural output force for observing the sensing position; J L It is the terminal moment of inertia; This refers to the terminal acceleration.

[0084] Furthermore, in the solution provided in the embodiments of this application, the load torque compensation model is as follows:

[0085]

[0086] Where, Δθ d This is the load torque compensation value; for Positively correlated odd functions.

[0087] For example,

[0088]

[0089] Wherein, α represents the friction parameter, which can be designed based on the actual test curve of stiffness-deformation from the intermediate feedback mechanism to the end.

[0090] To facilitate understanding of the beneficial effects of the solutions provided in the embodiments of this application, the following description is given in the form of examples.

[0091] As an example, the application of the embodiments of this application to a oscillating nozzle actuator is described. Typically, the actuator sensor is arranged on the output push rod, and the final nozzle attitude is ensured by structural stiffness. A time-varying load of ±100 Nm is input to the end of the actuator, and it follows a small-signal square wave control signal. See [link to documentation]. Figure 4 In scenario A, under conventional control methods, the nozzle attitude exhibits inconsistency between the load force and the pushrod feedback, causing the attitude to oscillate with load deviation. (See also...) Figure 4 In section B, after introducing dynamic load compensation high-precision control, the system load torque is accurately observed and compensated, realizing high dynamic and high-precision following control of nozzle attitude.

[0092] The solution provided in this application's embodiments observes the load torque in real time even without force feedback at the end point, compensating for the effects of load disturbances. The observed torque exhibits high accuracy, good stability, and low latency. Furthermore, even without sensor feedback at the end point, the observed intermediate torque is used to estimate the end-point acceleration, achieving high dynamic and high-precision control of the end point.

[0093] Figure 5 A schematic diagram of the structure of a dynamic compensation control device for an indirect measurement servo system provided in an embodiment of this application is shown. See also Figure 5 The device includes:

[0094] Modeling unit 501 is used to construct a simulation model of an indirect measurement servo system. The simulation model includes a first dynamic model of the motor and intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end-effector acceleration estimation model, a second dynamic model of the end-effector structure, and a load torque compensation model.

[0095] The first calculation unit 502 is used to input the initial load torque into the first dynamic model, and the first dynamic model calculates the torque estimate, position estimate and position sensing measurement value of the intermediate feedback mechanism based on the initial load torque.

[0096] The estimation unit 503 is used to take the torque estimate, position estimate, and position sensing measurement value of the intermediate feedback mechanism as input to the output torque observation model of the intermediate feedback mechanism to obtain the structural output force of the observed sensing position; and to take the position sensing measurement value of the intermediate feedback mechanism as input to the end acceleration estimation model to obtain the end acceleration;

[0097] The second calculation unit 504 uses the structural output force at the observed sensing position and the end acceleration as inputs to the second dynamic model to calculate the estimated value of the end load torque.

[0098] The compensation unit 505 is used to calculate a compensation value based on the estimated end load torque and the load torque compensation model, and to compensate the initial load torque based on the compensation value.

[0099] See Figure 6 This application provides a computer device, the computer device comprising:

[0100] Memory 601 is used to store at least one instruction executed by a processor;

[0101] Processor 602 is used to execute instructions stored in memory. Figure 1 The method described.

[0102] This application provides a computer-readable storage medium storing computer instructions that, when executed on a computer, cause the computer to perform... Figure 1 The method described.

[0103] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A dynamic compensation control method for an indirect measurement servo system, characterized by, The method comprises: constructing a simulation model of an indirect measurement servo system, wherein the simulation model comprises a first dynamics model of a motor and an intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end acceleration estimation model, a second dynamics model of an end structure, and a load torque compensation model; inputting an initial load torque to the first dynamics model, the first dynamics model calculating a torque estimation value, a position estimation value, and a position sensor measurement value of the intermediate feedback mechanism based on the initial load torque; inputting the torque estimation value, the position estimation value, and the position sensor measurement value of the intermediate feedback mechanism to the output torque observation model of the intermediate feedback mechanism to obtain a structure output force of a sensor position observed; and inputting the position sensor measurement value of the intermediate feedback mechanism to the end acceleration estimation model to obtain an end acceleration; inputting the structure output force of the sensor position observed and the end acceleration to the second dynamics model to calculate an end load torque estimation value; calculating a compensation value according to the end load torque estimation value and the load torque compensation model, and compensating the initial load torque based on the compensation value.

2. The method of claim 1, wherein, Wherein, the first dynamics model is: wherein x1 and x2 represent state variables; θ0 is a rotation stroke of a motor rotor; θ1 is a position sensor measurement value of an intermediate feedback mechanism; J0 is a rotational inertia in a motion direction of the motor rotor; J1 is an equivalent rotational inertia in a motion direction of the motor and the intermediate feedback mechanism; h 01 is a transmission ratio from the motor rotor to the intermediate feedback mechanism.

3. The method of claim 2, wherein, the output torque observation model of the intermediate feedback mechanism is: wherein, are the estimated values of the state variables x1, x2 and the redundant state variable x3, respectively, x3 = τ1, τ1 is the load torque of the end-to-middle feedback mechanism and the combined unmodeled error disturbance; τ m is the motor electromagnetic torque input; p is the tracking compensator gain; g(x1, x2) is the nonlinear error fitting term; q is the estimator gain.

4. The method of claim 3, wherein, the end acceleration estimation model is: where G 1L (s) is the end-effector acceleration estimation model, s represents complex frequency; J L is the end-effector rotational inertia; h 1L is the transmission ratio from the intermediate feedback mechanism to the end-effector; k 1L is the equivalent stiffness coefficient from the intermediate feedback mechanism to the end-effector; D 1L is the equivalent damping coefficient from the intermediate feedback mechanism to the end-effector; G F1 (s) is a conventional low-pass filter.

5. The method of claim 4, wherein, the second dynamics model is: wherein, is an estimate of the load moment applied to the end-effector; is the observed structural output force at the sensor location;J L is the end-effector rotational inertia; is the end-effector acceleration.

6. The method of claim 5, wherein, the load torque compensation model is: where Δθ d is a load torque compensation value; is a positive correlation odd function.

7. A dynamic compensation control device for an indirect measurement servo system, characterized by comprising: The method comprises: a modeling unit configured to construct a simulation model of an indirect measurement servo system, wherein the simulation model comprises a first dynamics model of a motor and an intermediate feedback mechanism in the servo system, an output torque observation model of the intermediate feedback mechanism, an end acceleration estimation model, a second dynamics model of an end structure, and a load torque compensation model; a first calculation unit configured to input an initial load torque to the first dynamics model, the first dynamics model calculating a torque estimation value, a position estimation value, and a position sensor measurement value of the intermediate feedback mechanism based on the initial load torque; an estimation unit configured to input the torque estimation value, the position estimation value, and the position sensor measurement value of the intermediate feedback mechanism to the output torque observation model of the intermediate feedback mechanism to obtain a structure output force of a sensor position observed; and input the position sensor measurement value of the intermediate feedback mechanism to the end acceleration estimation model to obtain an end acceleration; a second calculation unit configured to input the structure output force of the sensor position observed and the end acceleration to the second dynamics model to calculate an end load torque estimation value; a compensation unit configured to calculate a compensation value according to the end load torque estimation value and the load torque compensation model, and compensate the initial load torque based on the compensation value.

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