High-dynamic self-adaptive rapid nonsingular terminal sliding mode control method

Abstract

The invention belongs to the technical field of vehicle-mounted photoelectric tracking platforms, and particularly relates to a high-dynamic self-adaptive rapid nonsingular terminal sliding mode control method. Comprising the following steps: S1, establishing a disturbed kinetic model of the vehicle-mounted photoelectric tracking platform; s2, designing a disturbance observer according to the lumped disturbance estimator of the vehicle-mounted photoelectric tracking platform; s3, designing a self-adaptive fast nonsingular terminal sliding mode surface according to the disturbed kinetic model of the vehicle-mounted photoelectric tracking platform; and S4, based on the interference observer and the self-adaptive fast nonsingular terminal sliding mode surface, constructing a high-dynamic self-adaptive fast nonsingular terminal sliding mode controller with a self-adaptive approaching rate, and realizing high-precision tracking control of the vehicle-mounted photoelectric platform. According to the invention, the tracking precision, the anti-interference capability and the robust performance of the vehicle-mounted photoelectric tracking platform can be improved, and the overall performance of the vehicle-mounted photoelectric tracking platform is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle-mounted optoelectronic tracking platforms, and particularly relates to a high-dynamic adaptive fast non-singular terminal sliding mode control method. Background Art

[0002] With the development of optoelectronic technology, the requirements for the pointing accuracy and mobility of optoelectronic tracking platforms are getting higher and higher. However, during vehicle driving, the vehicle will be affected by carrier oscillation, wind disturbance, friction force and unbalanced torque, which poses great challenges to the vehicle-mounted optoelectronic platform for tracking targets. In order to achieve high-precision control of vehicle-mounted optoelectronic tracking platforms, relevant technicians in the field have adopted control methods such as feedforward control, PID control, and fuzzy control. However, as a multi-degree-of-freedom non-linear complex system, these control methods cannot accurately estimate the internal and external disturbances of the system and make rapid responses. The sliding mode control method has the characteristics of strong robustness and insensitivity to parameter changes. However, due to the switching action of the sliding mode surface, the phenomenon of "chattering" will occur, which is not conducive to the high-precision control of the system. In addition, the design of the constant switching term of traditional sliding mode control is relatively conservative, and for a system with high-dynamic characteristics, the design of this control method is not reasonable. Therefore, it is an urgent problem for technicians in this field to design a control method with high-dynamic characteristics, anti-disturbance performance, and high robustness. Summary of the Invention

[0003] In view of this, the present invention aims to provide a high-dynamic adaptive fast non-singular terminal sliding mode control method to solve the drawback that the design of the constant switching term of the existing sliding mode control method is relatively conservative and not applicable to the control system of optoelectronic tracking platforms with high-dynamic characteristics. The high-dynamic adaptive fast non-singular terminal sliding mode control method of the present invention can improve the tracking accuracy, anti-disturbance ability and robustness of vehicle-mounted optoelectronic tracking platforms, and thus improve the overall performance of vehicle-mounted optoelectronic tracking platforms.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows: A high-dynamic adaptive fast non-singular terminal sliding mode control method for realizing high-precision tracking control of a vehicle-mounted optoelectronic tracking platform specifically includes the following steps: S1: Establish a perturbed dynamic model of the vehicle-mounted optoelectronic tracking platform; S2: Design an interference observer according to the lumped disturbance estimator of the vehicle-mounted optoelectronic tracking platform; S3: Design an adaptive fast non-singular terminal sliding mode surface according to the perturbed dynamic model of the vehicle-mounted optoelectronic tracking platform; S4: Based on the disturbance observer and the adaptive fast nonsingular terminal sliding mode surface, construct a high-dynamic adaptive fast nonsingular terminal sliding mode controller with an adaptive approaching rate to achieve high-precision tracking control of the vehicle-mounted optoelectronic platform.

[0005] Furthermore, in step S1, the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform is: ; where , represents the rotation angle of the pitching joint, represents the rotation angle of the azimuth joint, , represents the angular velocity of the pitching joint, represents the angular velocity of the azimuth joint, , represents the angular acceleration of the pitching joint, represents the angular acceleration of the azimuth joint, represents the inertia coefficient matrix of the joint, represents the damping coefficient matrix, , represents the equivalent input quantity of the pitching joint motor control quantity, represents the equivalent input quantity of the azimuth joint motor control quantity, , represents the disturbance component of the lumped disturbance of the vehicle-mounted optoelectronic tracking platform in the pitching joint, represents the disturbance component of the lumped disturbance in the azimuth joint.

[0006] Furthermore, in step S2, the expression of the disturbance observer is: ; where , represents the estimated quantity of the disturbance component of the lumped disturbance in the pitching joint, represents the estimated quantity of the disturbance component of the lumped disturbance in the azimuth joint, , is the auxiliary variable of the pitching joint disturbance observer, is the auxiliary variable of the azimuth joint disturbance observer, is the derivative of , , represents the disturbance observer gain of the pitching joint, represents the disturbance observer gain of the azimuth joint.

[0007] Furthermore, define the angular velocity error between the joint command velocity and the joint rotation velocity ​ is: ; wherein, , represents the angular velocity error of the pitch joint, represents the angular velocity error of the azimuth joint.

[0008] Furthermore, in step S3, the expression of the adaptive fast nonsingular terminal sliding mode surface s is: ; wherein, , represents the sliding mode surface of the pitch joint adaptive fast nonsingular terminal sliding mode controller, represents the sliding mode surface of the azimuth joint adaptive fast nonsingular terminal sliding mode controller, , represents the angular acceleration error of the pitch joint, represents the angular acceleration error of the azimuth joint, , , and both represent the gains of the pitch joint sliding mode surface and are constant coefficient variables, and both represent the gains of the azimuth joint sliding mode surface and are constant coefficient variables, is to the power of, is to the power of, , is the sign function.

[0009] Furthermore, in step S4, the adaptive reaching law is: ; wherein, , represents the adaptive reaching law of the pitch joint adaptive fast nonsingular terminal sliding mode controller, represents the adaptive reaching law of the azimuth joint adaptive fast nonsingular terminal sliding mode controller, , represents the adaptive gain of the pitch joint adaptive fast nonsingular terminal sliding mode controller, represents the adaptive gain of the azimuth joint adaptive fast nonsingular terminal sliding mode controller, is the estimated value of the adaptive gain , , is the gain of the pitch joint adaptive reaching law, is the gain of the azimuth joint adaptive approaching rate.

[0010] Further, in step S4, the high-dynamic adaptive fast nonsingular terminal sliding mode controller is: .

[0011] Compared with the prior art, the present invention can achieve the following beneficial effects: The high-dynamic adaptive fast nonsingular terminal sliding mode control method described in the present invention takes into account the nonlinearity, parameter uncertainty of the optoelectronic tracking platform model and the high-precision tracking requirements, uses an interference observer to estimate and compensate for disturbances, and designs a high-dynamic adaptive fast nonsingular terminal sliding mode control method with an adaptive switching gain. On the one hand, it weakens the influence of the "chattering" phenomenon, and on the other hand, it can make the control system of the optoelectronic tracking platform quickly converge to the equilibrium state, realizing the high-dynamic and high-precision control of the vehicle-mounted optoelectronic tracking platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic flow chart of the high-dynamic adaptive fast nonsingular terminal sliding mode control method described in the embodiment of the present invention; Figure 2 is a structural block diagram of the high-dynamic adaptive fast nonsingular terminal sliding mode control method described in the embodiment of the present invention; Figure 3 is a lumped disturbance curve graph of the vehicle-mounted optoelectronic tracking platform in the vehicle-mounted scenario described in the embodiment of the present invention; Figure 4 is a comparison diagram of the stable tracking effects of the vehicle-mounted optoelectronic tracking platform under the action of the high-dynamic adaptive fast nonsingular terminal sliding mode control method and the sliding mode composite control method described in the embodiment of the present invention; Figure 5 is a comparison schematic diagram of the tracking error simulation curves under the action of the high-dynamic adaptive fast nonsingular terminal sliding mode control method and the sliding mode composite control method described in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0014] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0015] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0016] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0017] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0018] As Figure 1 shown, the present invention proposes a high-dynamic adaptive fast non-singular terminal sliding mode control method for realizing high-precision tracking control of an on-vehicle optoelectronic tracking platform, which specifically includes the following steps: S1: Establish a perturbed dynamic model of the on-vehicle optoelectronic tracking platform; S2: Design an interference observer according to the lumped disturbance estimation quantity of the on-vehicle optoelectronic tracking platform; S3: Design an adaptive fast non-singular terminal sliding mode surface according to the perturbed dynamic model of the on-vehicle optoelectronic tracking platform; S4: Based on the interference observer and the adaptive fast non-singular terminal sliding mode surface, construct a high-dynamic adaptive fast non-singular terminal sliding mode controller with an adaptive approaching rate to realize high-precision tracking control of the on-vehicle optoelectronic platform.

[0019] The present invention first analyzes the structure of the vehicle-mounted optoelectronic tracking platform and establishes a disturbed dynamic model of the two-degree-of-freedom vehicle-mounted optoelectronic tracking platform with uncertainty; then, according to the characteristics of the disturbance of the vehicle-mounted optoelectronic tracking platform (specifically, the lumped disturbance estimator), a disturbance observer is designed to estimate and compensate the lumped disturbance of the vehicle-mounted optoelectronic tracking platform. The lumped disturbance refers to the set of disturbances suffered by the vehicle-mounted optoelectronic tracking platform during operation, including but not limited to wind disturbance, internal friction, vibration of the carrier, etc., and these disturbances are all unmeasurable; then, according to the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform, a fast non-singular terminal sliding surface (dynamic) is designed; finally, in order to suppress the influence brought by the switching of the sliding surface, a high-dynamic adaptive fast non-singular terminal sliding mode controller with an adaptive approaching rate is designed to meet the requirement of high-precision tracking control of the vehicle-mounted stable platform. The control method proposed by the present invention can observe and estimate the uncertain factors in the system model in real time.

[0020] In some embodiments, in step S1, the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform is: ; Wherein, , represents the rotation angle of the pitching joint, represents the rotation angle of the azimuth joint, , represents the angular velocity of the pitching joint, represents the angular velocity of the azimuth joint, , represents the angular acceleration of the pitching joint, represents the angular acceleration of the azimuth joint, represents the inertia coefficient matrix of the joint, represents the damping coefficient matrix, , represents the equivalent input quantity of the pitching joint motor control quantity, represents the equivalent input quantity of the azimuth joint motor control quantity, , represents the disturbance component of the lumped disturbance of the vehicle-mounted optoelectronic tracking platform in the pitching joint, represents the disturbance component of the lumped disturbance in the azimuth joint.

[0021] In some embodiments, in step S2, the expression of the disturbance observer is: ; Wherein, , represents the estimator of the disturbance component of the lumped disturbance in the pitching joint, represents the estimator of the disturbance component of the lumped disturbance in the azimuth joint, , is the auxiliary variable of the pitch joint disturbance observer, is the auxiliary variable of the azimuth joint disturbance observer, is the derivative of, , denotes the disturbance observer gain of the pitch joint, denotes the disturbance observer gain of the azimuth joint.

[0022] It should be noted that the disturbance observer is used to compensate for external disturbances.

[0023] In some embodiments, the joint command velocity and the angular velocity error of the joint rotation speed are defined as: ; ; wherein, , denotes the angular velocity error of the pitch joint, denotes the angular velocity error of the azimuth joint.

[0024] In some embodiments, in step S3, the expression of the adaptive fast nonsingular terminal sliding mode surface s is: ; wherein, , denotes the sliding mode surface of the adaptive fast nonsingular terminal sliding mode controller of the pitch joint, denotes the sliding mode surface of the adaptive fast nonsingular terminal sliding mode controller of the azimuth joint, , denotes the angular acceleration error of the pitch joint, denotes the angular acceleration error of the azimuth joint, , , and both denote the gains of the sliding mode surface of the pitch joint and are constant coefficient variables, and both denote the gains of the sliding mode surface of the azimuth joint and are constant coefficient variables, is the power of, is the power of, , is the sign function.

[0025] It should be noted that the sign function is defined as: .

[0026] In some embodiments, in step S4, the adaptive reaching law is: ; wherein, , represents the adaptive reaching law of the pitch joint adaptive fast non-singular terminal sliding mode controller, represents the adaptive reaching law of the azimuth joint adaptive fast non-singular terminal sliding mode controller, , represents the adaptive gain of the pitch joint adaptive fast non-singular terminal sliding mode controller, represents the adaptive gain of the azimuth joint adaptive fast non-singular terminal sliding mode controller, is the estimated value of the adaptive gain , , is the gain of the pitch joint adaptive reaching law, is the gain of the azimuth joint adaptive reaching law.

[0027] Specifically, the formula used to obtain is: ; wherein, and are both constant coefficients, , E represents pitch, A represents azimuth, is element in.

[0028] In some embodiments, in step S4, the high-dynamic adaptive fast non-singular terminal sliding mode controller is: .

[0029] As Figure 2 shown, the difference between the desired angular velocity of the vehicle-mounted optoelectronic tracking platform and the actual angular velocity output by the vehicle-mounted optoelectronic tracking platform is used as the input of the high-dynamic adaptive fast non-singular terminal sliding mode controller. The feedback element here can be selected from gyroscopes, encoders or cameras, etc. In the present invention, an encoder is used as the feedback element. On this basis, with the obtained angular velocity error as the input, an adaptive fast non-singular terminal sliding mode controller is designed. The design of the controller includes two parts. The first part is to design a sliding mode surface according to the error between the desired angular velocity and the actual angular velocity. Subsequently, in order to suppress the "chattering" phenomenon of the sliding mode surface, an adaptive reaching law is designed to estimate and compensate for the interference. Under the combined action of the interference observer and the adaptive fast non-singular terminal sliding mode controller, high-performance control of the vehicle-mounted optoelectronic tracking platform is achieved.

[0030] AsFigure 3 As shown Figure 3 When the curve shown in Figure 3 is from 1 second to 2.2 seconds, a lumped interference signal is applied to the vehicle-mounted optoelectronic tracking platform.

[0031] As Figure 4 shown, the vehicle-mounted optoelectronic tracking platform has tracked the sine signal with high precision. The stable tracking effects of the vehicle-mounted optoelectronic tracking platform under the action of the composite control method (red curve) composed of the disturbance observer and the adaptive fast nonsingular terminal sliding mode controller proposed in the present invention and the sliding mode composite control method (green curve) composed of the disturbance observer and the sliding mode control method are compared. As Figure 4 can be seen, the method proposed in the present invention can achieve high-performance tracking control of the vehicle-mounted optoelectronic tracking platform.

[0032] As Figure 5 shown, under the action of the method proposed in the present invention, the controller can achieve the compensation effect for external disturbances. Compared with the comparative method, the method proposed in the present invention has better disturbance suppression and compensation performance.

[0033] All symbols in the full text, if in boldface roman, represent vectors, and if in italic without boldface, represent single variables.

[0034] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recorded in the disclosure of the present invention can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved. No limitation is made herein.

[0035] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-dynamic adaptive fast nonsingular terminal sliding mode control method for realizing high-precision tracking control of an on-vehicle optoelectronic tracking platform, characterized in that: Specifically, it includes the following steps: S1: Establish the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform; S2: Design an interference observer according to the lumped disturbance estimation quantity of the vehicle-mounted optoelectronic tracking platform; S3: Design an adaptive fast non-singular terminal sliding mode surface according to the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform; S4: Based on the interference observer and the adaptive fast non-singular terminal sliding mode surface, construct a high-dynamic adaptive fast non-singular terminal sliding mode controller with an adaptive approaching rate to achieve high-precision tracking control of the vehicle-mounted optoelectronic platform.

2. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 1, wherein: In step S1, the disturbed dynamic model of the vehicle-mounted optoelectronic tracking platform is: ； Among them, , represents the rotation angle of the pitch joint, represents the rotation angle of the azimuth joint, , represents the angular velocity of the pitch joint, represents the angular velocity of the azimuth joint, , represents the angular acceleration of the pitch joint, represents the angular acceleration of the azimuth joint, represents the moment of inertia coefficient matrix of the joint, represents the damping coefficient matrix, , represents the equivalent input quantity of the pitch joint motor control quantity, represents the equivalent input quantity of the azimuth joint motor control quantity, , represents the disturbance component of the lumped disturbance of the vehicle-mounted optoelectronic tracking platform in the pitch joint, represents the disturbance component of the lumped disturbance in the azimuth joint.

3. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 2, characterized in that: In step S2, the expression of the interference observer is: ； Among them, , represents the estimated value of the disturbance component of the lumped disturbance in the pitch joint, represents the estimated value of the disturbance component of the lumped disturbance in the azimuth joint, , is the auxiliary variable of the disturbance observer for the pitch joint, is the auxiliary variable of the disturbance observer for the azimuth joint, is the derivative of, , represents the disturbance observer gain of the pitch joint, represents the disturbance observer gain of the azimuth joint.

4. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 2, characterized in that: Define the joint command speed and the angular velocity error of the joint rotation speed is as follows: ； Among them, , represents the angular velocity error of the pitch joint, represents the angular velocity error of the azimuth joint.

5. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 4, characterized in that: In step S3, the expression of the adaptive fast non-singular terminal sliding mode surface s is: ； Among them, , represents the sliding mode surface of the pitch joint adaptive fast non-singular terminal sliding mode controller, represents the sliding mode surface of the azimuth joint adaptive fast non-singular terminal sliding mode controller, , represents the angular acceleration error of the pitch joint, represents the angular acceleration error of the azimuth joint, , , and both represent the gains of the pitch joint sliding mode surface and are constant coefficient variables, and both represent the gains of the azimuth joint sliding mode surface and are constant coefficient variables, is 's power, is 's power, , is the sign function.

6. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 5, characterized in that: In step S4, the adaptive reaching law is as follows: ； Among them, , represents the adaptive approaching rate of the pitch joint adaptive fast non-singular terminal sliding mode controller, represents the adaptive approaching rate of the azimuth joint adaptive fast non-singular terminal sliding mode controller, , represents the adaptive gain of the pitch joint adaptive fast non-singular terminal sliding mode controller, represents the adaptive gain of the azimuth joint adaptive fast non-singular terminal sliding mode controller, is the estimated value of the adaptive gain , , is the gain of the pitch joint adaptive approaching rate, is the gain of the azimuth joint adaptive approaching rate.

7. The high-dynamic adaptive fast nonsingular terminal sliding mode control method according to claim 6, characterized in that: In step S4, the high-dynamic adaptive fast nonsingular terminal sliding mode controller is as follows: 。

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