A gyro feedback-based augmented loop control method for electromechanical systems

Abstract

The application discloses a gyro feedback-based electromechanical system augmented loop control method, which splits a traditional speed loop of three closed loops of position, rotating speed and current into an inner motor rotating speed ring and an outer gyro stable augmented loop, and constructs a position-gyro-motor rotating speed-current four-stage series closed loop structure. The motor rotating speed ring adopts PID, sliding mode, MPC and the like control and is equivalent to a first-order link; gyro augmented kinematic equations are established by fusing platform nonlinearity, unknown disturbance and a rotating speed ring model, a nonlinear control law containing feedforward compensation is designed according to the gyro augmented kinematic equations, and it is proved by Lyapunov theory that the system is uniformly ultimately bounded stable. The scheme can decouple and separate platform nonlinearity and motor torque disturbance, separately suppresses disturbance in a sub-loop, is simple in calculation and easy to implement in engineering, and can significantly improve the closed loop stability of an inertia stable platform with significant nonlinearity.

Description

Technical Field

[0001] This invention relates to the field of electromechanical servo control, and more specifically to an augmented loop control method for electromechanical systems based on gyroscope feedback. Background Technology

[0002] Gyro-feedback-based electromechanical systems are widely used in various inertial stabilization platforms, such as optoelectronic / electronic pods, aerial gimbals, and vehicle-mounted radar. These inertial stabilization platforms are typically mounted on movable platforms to isolate base disturbances, maintain the line-of-sight angle stability of measurement sensors, and simultaneously achieve pitch, azimuth, and other angle tracking. The feedback gyroscope can simultaneously sense the rotation of both the base and the servo motors of the stabilization platform, which is crucial for achieving inertial space stability.

[0003] Such servo platforms are typically modeled as third-order systems. Currently, in engineering, a three-loop control structure of current, speed, and position is generally adopted, along with corresponding feedforward and disturbance observation techniques to enhance control performance. However, the introduction of gyroscope sensors provides multiple options for speed control loop design, namely motor speed feedback, gyroscope measurement feedback, or a combination of both. In a closed-loop loop based on gyroscope feedback, motor speed fluctuations and platform base motion are simultaneously coupled into the control loop, directly affecting control performance. The traditional approach of the three-loop control mode is to consider the combined effects of both and compensate for them separately using technical means. However, this increases the control burden on the gyroscope loop, especially for a type of non-direct-drive servo stabilization platform (transmission via mechanical mechanisms such as guide rods and reducers). Improper handling can easily lead to system instability and even cause the servo product to overspeed and break down.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To avoid the shortcomings of existing technologies, this invention provides an augmented loop control method based on gyroscope feedback, which solves the problem of complex speed loop control and instability in direct-drive or non-direct-drive servo stabilization platforms.

[0006] Other features and advantages of the invention will become apparent from the following detailed description, or may be learned in part by practice of the invention.

[0007] According to a first aspect of the present invention, an augmented loop control method based on gyroscope feedback is provided, the method comprising: A system model is established for the inertial stabilization platform installed on the moving base. Based on the system model, the speed control loop in the traditional three-loop control of position, speed, and current in a servo system is split into a motor speed control loop and a gyroscope stabilization loop. The motor speed control loop is the inner loop, and the gyroscope stabilization loop is the outer loop. Together, they form a four-loop control structure in which the position outer loop, gyroscope stabilization loop, motor speed loop, and current inner loop are connected in series. The motor speed control loop is designed using PID, sliding mode, or model prediction MPC control methods. After completing the closed loop, the motor speed control loop is equivalently approximated as a first-order transfer function. The gyroscope stabilization loop is the augmented control loop. The angular rate gyroscope installed on the stabilization platform is used as the measurement feedback signal. By constructing the kinematic equation of the gyroscope augmented loop and combining relevant knowledge of control theory, a nonlinear control law is designed to realize the augmented loop control. The stability of the system is analyzed with the help of Lyapunov theory. The kinematic equation of the gyroscope augmented loop is a differential equation constructed by approximating the motor speed control loop as a first-order transfer function and further integrating the nonlinearity of the stable platform and the characteristics of the unknown model, with gyroscope measurement as the system state.

[0008] In some exemplary embodiments, the mathematical system model is specifically as follows:

[0009] In the formula, The inertial space angle represents the angle of inertia of the stable platform. Represents a nonlinear function. Indicates the angular rate of base rotation. Indicates the servo motor speed. Represents the moment of inertia. Indicates the torque coefficient. Indicates the load torque. Indicates the motor input current. This indicates an unknown perturbation in the model.

[0010] In some exemplary embodiments, the motor speed control loop is equivalent to a first-order system, denoted as: (3) In the formula, Represents the time constant of the equivalent first-order system. This indicates the input command for the motor speed control circuit.

[0011] In some exemplary embodiments, the process of constructing the kinematic equations of the gyroscope augmented loop consists of the following two steps: Step 1: Obtain the computational model for gyroscope feedback, specifically represented as follows: (4) In the formula, This indicates the gyroscope feedback angular rate; The second step: Differentiate equation (4) and combine it with equation (3) to obtain...

[0012] Equation (5) is the kinematic equation of the augmented loop of the gyroscope described by the differential equation.

[0013] In some exemplary embodiments, the process of designing the nonlinear control law for the gyroscope feedback augmentation loop involves the following three steps: Step 1: Define angular rate tracking error for (6) Step 2: Differentiate equation (6) (7) Step 3: Design the gyroscope augmentation loop control law using equation (7). (8) In the formula, Indicates design parameters, This represents the feedforward control quantity, calculated as follows: (9).

[0014] In some exemplary embodiments, the Lyapunov-based stability analysis process is as follows: First, assume unknown disturbance. and It is a bounded quantity, and ,in First, let the integers be positive constants; second, define the Lyapunov function. (10) Differentiating equation (10) and simultaneously solving equations (7) and (8), we get (11) In the formula, For bounded small quantities, take the design parameters. This ensures that all variables in the Lyapunov function have uniformly bounded final values, indicating that the designed gyroscope augmentation loop is stable.

[0015] In some exemplary embodiments, the four-closed-loop control structure is hierarchically arranged from the outside to the inside as follows: position control loop, gyroscope stabilization augmentation loop, motor speed control loop, and current control loop; wherein the external torque disturbance of the motor is coupled to the inner motor speed control loop, and the nonlinear characteristics of the stabilization platform and the base disturbance are coupled to the outer gyroscope stabilization augmentation loop, thereby achieving decoupling and independent processing of the two types of disturbances in separate loops.

[0016] According to a second aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the augmented loop control method based on gyroscope feedback described in the first aspect.

[0017] According to a third aspect of the present invention, a computer program product is provided, on which a computer program is stored, wherein when the computer program is executed by a processor, the augmented loop control method based on gyroscope feedback described in the first aspect is implemented.

[0018] According to a fourth aspect of the present invention, an electronic device is provided, comprising: Processor; and Memory for storing the executable instructions of the processor; The processor is configured to implement the gyroscope-feedback-based augmented loop control method described in the first aspect by executing the executable instructions.

[0019] The gyroscope-feedback-based augmented loop control method for electromechanical systems provided in the embodiments of the present invention has the following advantages compared with the prior art: 1. Interference decoupling and separation: The platform nonlinearity, base disturbance and motor external torque interference are separated and processed separately in the gyroscope outer loop and the motor speed inner loop, eliminating the control pressure caused by the superposition of the two types of interference coupling, and avoiding instability and runaway problems of non-direct drive platform.

[0020] 2. Reduced control difficulty: The addition of a gyroscope augmentation loop to share the attitude stabilization task greatly simplifies the design difficulty of the outermost position loop controller and improves the line-of-sight stabilization isolation effect.

[0021] 3. Excellent stability performance: The stability is proven based on Lyapunov theory. The system has a consistent final value and strong robustness, making it suitable for inertial stability platforms with prominent nonlinear characteristics.

[0022] 4. Strong engineering applicability: The control algorithm has low computational load, and the speed loop is compatible with multiple mature control algorithms such as PID, sliding mode, and MPC. It is applicable to both direct-drive and non-direct-drive servo systems with reducers, and is suitable for various types of equipment such as optoelectronic pods, vehicle-mounted radar, and aerial photography gimbals.

[0023] 5. Wide applicability: The traditional three-closed-loop servo architecture can be transformed simply by reconfiguring the loop, without the need for major changes to the hardware structure. The transformation cost is low and the porting is convenient.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0026] Figure 1 This is a flowchart of a method according to an embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the invention will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0028] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0029] To address the control problems faced by existing inertial stabilization platforms, this invention discloses an augmented loop control method based on gyroscope feedback, and analyzes the stability of the augmented loop using Lyapunov theory. This method can decompose the external torque disturbance of the motor and the complex nonlinear problems of the stabilization platform into two separate control loops for handling, providing a reliable engineering control method for both direct-drive and non-direct-drive inertial stabilization servo systems.

[0030] refer to Figure 1 As shown, the specific steps may include: For a type of inertial stabilization platform installed on a moving base, the speed control loop in the original three-closed-loop control loop of position, speed, and current is split into two parts: a motor speed control loop and a gyroscope stabilization loop. The motor speed is the inner loop, and the gyroscope stabilization is the outer loop, ultimately forming a four-closed-loop control structure. The motor speed control loop includes, but is not limited to, PID (proportional, integral, derivative), sliding mode, MPC (model prediction) and other control methods, and the designed closed loop can be approximately described as a first-order transfer function; The gyroscope stabilization loop is the augmented control loop. The angular rate gyroscope installed on the stabilization platform is used as the measurement feedback signal. By constructing the kinematic equation of the gyroscope augmented loop and combining relevant knowledge of control theory, a nonlinear control law is designed to realize the augmented loop control. The stability of the system is analyzed with the help of Lyapunov theory. The kinematic equation of the gyroscope augmented loop is a differential equation constructed by approximating the motor speed control loop as a first-order transfer function and further integrating the nonlinearity of the stable platform and the characteristics of the unknown model, with gyroscope measurement as the system state. The four-loop control structure refers to a closed-loop structure consisting of four control loops connected in series: position, gyroscope feedback, motor speed, and current. The position loop is the outermost loop, and the current loop is the innermost loop.

[0031] The steps in this exemplary embodiment will now be described in more detail with reference to the accompanying drawings and embodiments.

[0032] The mathematical model of the inertial stabilization platform installed on the moving base can be expressed as follows:

[0033] In the formula, The inertial space angle represents the angle of inertia of the stable platform. Represents a nonlinear function. Indicates the angular rate of base rotation. Indicates the servo motor speed. Represents the moment of inertia. Indicates the torque coefficient. Indicates the load torque. Indicates the motor input current. This indicates an unknown perturbation in the model.

[0034] The motor speed closed-loop control loop can be equivalent to a first-order system, represented as follows: (3) In the formula, The time constant of the equivalent first-order system is generally... Specifically, it depends on the control bandwidth of the motor speed circuit. This indicates the input command for the motor speed control circuit.

[0035] The process of constructing the kinematic equations of the augmented loop of the gyroscope consists of the following two steps: Step 1: Obtain the computational model for gyroscope feedback, specifically represented as follows: (4) In the formula, This indicates the gyroscope feedback angular rate.

[0036] The second step: Differentiate equation (4) and combine it with equation (3) to obtain...

[0037] Equation (5) is the kinematic equation of the augmented loop of the gyroscope described by the differential equation.

[0038] The process of designing the nonlinear control law for the gyroscope feedback augmentation loop is as follows: Step 1: Define angular rate tracking error for (6) Step 2: Differentiate equation (6) (7) Step 3: Design the gyroscope augmentation loop control law using equation (7). (8) In the formula, Indicates design parameters, This represents the feedforward control quantity, calculated as follows: (9) The stability analysis process based on Lyapunov is as follows: First, assume unknown disturbance. and It is a bounded quantity, and ,in It is a positive constant. Secondly, define the Lyapunov function. (10) Differentiating equation (10) and simultaneously solving equations (7) and (8), we get (11) In the formula, For bounded small quantities, take the design parameters. This ensures that all variables in the Lyapunov function have uniformly bounded final values, indicating that the designed gyroscope augmentation loop is stable.

[0039] To more clearly illustrate the benefits of this invention, the system equations after transformation by the gyroscope feedback augmentation loop are rearranged into the following form.

[0040] Compared with the original system equations (1) and (2), the transformed system equations add a gyro feedback kinematic equation (13), and the motor speed differential equation (14) is approximated as a first-order system. The above transformations indicate that the external torque disturbance affecting the motor speed is implicitly represented in the speed control closed loop. Nonlinear terms related to platform motion... and unknown disturbances It is explicitly represented in the gyroscope feedback loop. Furthermore, the inertial space angle equation (12) is simplified to a first-order pure integral system. This algorithm has guiding significance and promotional value for practical control engineering problems. Specifically, it is as follows: 1. The introduction of a gyroscope augmentation loop reduces the difficulty of position loop control; 2. The coupling effect of the platform's nonlinear characteristics and the external torque interference of the motor was effectively separated, and the two were successfully separated into different control loops for processing; 3. This method has the advantages of simple calculation, good stability, and strong engineering feasibility; 4. This method is particularly suitable for a class of inertial stabilization systems with significant platform nonlinear characteristics.

[0041] Example 1 Step 1: Establish the system model. Assume a direct-drive inertial stabilized platform is mounted on a moving base, and let... , At this point, the system model can be represented as

[0042] In the formula, The inertial space angle represents the angle of inertia of the stable platform. Indicates the angular rate of base rotation. Indicates the servo motor speed. Represents the moment of inertia. Indicates the torque coefficient. Indicates the load torque. This indicates the motor input current.

[0043] Step 2: Design the motor speed loop control law using PID, sliding mode and other control methods, and obtain the same equivalent first-order system model as Equation (3).

[0044] Step 3: Derive the kinematic equations of the augmented loop of the gyroscope, and obtain

[0045] In the formula, This indicates the gyroscope feedback angular rate.

[0046] Step 4: Design the augmented loop control law

[0047] In the formula, Indicates design parameters, angular rate tracking error .

[0048] Step 5: Similar to equation (11), the stability of the gyroscope augmented loop control designed based on Lyapunov analysis.

[0049] Simulation analysis and experimental verification show that, compared with the three-loop control method (position, speed, and current), augmented loop control has a significant advantage in improving system control performance. The method of this invention is correct, effective, and easy to implement in engineering.

[0050] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0051] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is defined only by the appended claims.

Claims

1. A method for augmented loop control of an electromechanical system based on gyroscope feedback, characterized in that, The method includes: A system model is established for the inertial stabilization platform installed on the moving base. Based on the system model, the speed control loop in the traditional three-loop control of position, speed, and current in a servo system is split into a motor speed control loop and a gyroscope stabilization loop. The motor speed control loop is the inner loop, and the gyroscope stabilization loop is the outer loop. Together, they form a four-loop control structure in which the position outer loop, gyroscope stabilization loop, motor speed loop, and current inner loop are connected in series. The motor speed control loop is designed using PID, sliding mode, or model prediction MPC control methods. After completing the closed loop, the motor speed control loop is equivalently approximated as a first-order transfer function. The gyroscope stabilization loop is the augmented control loop. The angular rate gyroscope installed on the stabilization platform is used as the measurement feedback signal. By constructing the kinematic equation of the gyroscope augmented loop and combining relevant knowledge of control theory, a nonlinear control law is designed to realize the augmented loop control. The stability of the system is analyzed with the help of Lyapunov theory. The kinematic equation of the gyroscope augmented loop is a differential equation constructed by approximating the motor speed control loop as a first-order transfer function and further integrating the nonlinearity of the stable platform and the characteristics of the unknown model, with gyroscope measurement as the system state.

2. The augmented loop control method for electromechanical systems based on gyroscope feedback according to claim 1, characterized in that, The mathematical system model is specifically as follows: In the formula, The inertial space angle represents the angle of inertia of the stable platform. Represents a nonlinear function. Indicates the angular rate of base rotation. Indicates the servo motor speed. Represents the moment of inertia. Indicates the torque coefficient. Indicates the load torque. Indicates the motor input current. This indicates an unknown perturbation in the model.

3. The augmented loop control method for electromechanical systems based on gyroscope feedback according to claim 2, characterized in that, The motor speed control loop is equivalent to a first-order system, denoted as: （3） In the formula, Represents the time constant of the equivalent first-order system. This indicates the input command for the motor speed control circuit.

4. The augmented loop control method for electromechanical systems based on gyroscope feedback according to claim 3, characterized in that, The process of constructing the kinematic equations of the augmented loop of the gyroscope consists of the following two steps: Step 1: Obtain the computational model for gyroscope feedback, specifically represented as follows: （4） In the formula, This indicates the gyroscope feedback angular rate; The second step: Differentiate equation (4) and combine it with equation (3) to obtain... Equation (5) is the kinematic equation of the augmented loop of the gyroscope described by the differential equation.

5. The augmented loop control method for electromechanical systems based on gyroscope feedback according to claim 4, characterized in that, The process of designing the nonlinear control law for the gyroscope feedback augmentation loop is as follows: Step 1: Define angular rate tracking error for （6） Step 2: Differentiate equation (6) （7） Step 3: Design the gyroscope augmentation loop control law using equation (7). （8） In the formula, Indicates design parameters, This represents the feedforward control quantity, calculated as follows: （9）。 6. The augmented loop control method for electromechanical systems based on gyroscope feedback according to claim 5, characterized in that, The stability analysis process based on Lyapunov is as follows: First, assume unknown disturbance. and It is a bounded quantity, and ,in First, let the integers be positive constants; second, define the Lyapunov function. （10） Differentiating equation (10) and simultaneously solving equations (7) and (8), we get （11） In the formula, For bounded small quantities, take the design parameters. This ensures that all variables in the Lyapunov function have uniformly bounded final values, indicating that the designed gyroscope augmentation loop is stable.

7. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the gyroscope-feedback-based augmented loop control method for electromechanical systems as described in any one of claims 1 to 6.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the augmented loop control method for electromechanical systems based on gyroscope feedback as described in any one of claims 1 to 6.

9. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the gyroscope-feedback-based electromechanical system augmented loop control method of any one of claims 1 to 6 by executing the executable instructions.

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