A method for pre-setting time synchronization control of shipborne large inertia antenna servo system

Abstract

A method for pre-set time synchronization control of a shipborne large inertia antenna servo system belongs to the technical field of dual motor servo system control. The method includes establishing a dynamic model of the shipborne large inertia antenna servo system, initializing the state and control parameters of the system, designing a pre-set time disturbance observer, quickly estimating and compensating for external disturbances such as sea wind and waves, designing a non-singular pre-set time sliding surface, and designing a non-singular pre-set time synchronization and tracking controller on this basis. The present invention can effectively suppress the influence of external disturbances such as sea wind and waves on the shipborne large inertia antenna servo system, ensure that the upper limit of the minimum convergence time of the observation error and the control error can be preset by adjusting an adjustable parameter, avoid controller singularity, reduce computational complexity, and realize that the synchronization error and the tracking error converge to the neighborhood near the origin within a pre-set time.

Description

Technical Field

[0001] The invention belongs to the technical field of dual-motor servo system and shipborne large-inertia servo system control. Aiming at the problem that the shipborne large-inertia antenna servo system is easily affected by external interference such as sea wind and waves and the singularity of the controller, a predetermined time synchronization control method for the shipborne large-inertia antenna servo system is proposed. Background Art

[0002] The shipboard antenna servo system is an important part of the wireless measurement and control system. In order to improve the communication coverage, deep-sea communication usually requires a shipboard large-inertia antenna servo system. However, the output power of a single motor is limited, and the design cost of a high-power motor is high, making it difficult to be widely used in the field of marine engineering equipment. In order to improve the output power of the shipboard antenna servo system, multiple motors are used to synchronously drive large-inertia loads, which is conducive to the rapid response of the system.

[0003] At present, there are relatively few studies on multi-motor synchronous drive systems, especially in the field of shipborne large inertia antenna servo systems, where research is still in its infancy. In order to improve the convergence speed of synchronization and tracking errors, researchers have proposed a finite-time synchronization and tracking control method for dual-motor drive servo systems, and overcome the influence of transmission lag, parameter drift and motor dynamic characteristics differences. However, the convergence time of finite-time control depends on the initial value and has a complex relationship with the control parameters, and cannot be obtained by only a simple parameter. Predetermined time control can pre-set the upper bound of the convergence time by adjusting a control parameter, simplifying the relationship between the convergence time and the control parameters, and is independent of the initial state of the system. However, both finite-time control and predetermined time control have singularity problems, which make the control input tend to infinity. Although the existing piecewise continuous function method can avoid singularity, it increases the complexity of the calculation. Therefore, it is very necessary to study non-singular predetermined time synchronization and tracking controllers that do not increase the computational complexity.

[0004] When the shipborne large inertia antenna servo system works in the marine environment, it will inevitably be affected by unknown external interferences such as waves and sea wind, thus affecting the control accuracy of the system. Therefore, it is of great significance to study the anti-interference control method of the shipborne large inertia antenna servo system to compensate for the influence of waves and sea wind. Most of the existing work uses physical shock absorption methods such as stable platforms to compensate for the interference of waves and sea wind, which is difficult to meet the rapidity and high precision requirements of offshore operations. Therefore, researchers designed finite-time disturbance observers and fixed-time disturbance observers to quickly estimate and compensate for external interference systems. However, the upper bound of the convergence time of the observation error is difficult to accurately adjust according to the actual sea conditions.

[0005] Therefore, for the shipborne large-inertia antenna servo system with sea breeze and wave interference, it is of great research significance to design a control method that can quickly estimate and compensate for external interference, make the minimum convergence time upper bound of the observation error and the control error only related to one adjustable parameter, avoid controller singularity, reduce computational complexity, and achieve predetermined time synchronization and tracking. Summary of the invention

[0006] In order to reduce the influence of external disturbances such as sea breeze and waves on the shipborne large inertia antenna servo system, ensure that the synchronization and tracking errors converge to the neighborhood near the origin within a preset time, and make the minimum convergence time upper bound of the observation error and the control error only related to an adjustable parameter, the present invention proposes a predetermined time synchronization control method for the shipborne large inertia antenna servo system. Firstly, a predetermined time disturbance observer is constructed to estimate and compensate for external disturbances such as sea breeze and waves; secondly, a non-singular predetermined time synchronization and tracking controller is designed based on the predetermined time sliding surface to reduce the calculation complexity; the present invention can quickly compensate for external disturbances such as sea breeze and waves, ensure that the observation error and the control error converge to the neighborhood near the origin within a preset time, and the minimum convergence time upper bound can be preset by adjusting an adjustable parameter.

[0007] In order to solve the above technical problems, the present invention proposes a method for controlling the predetermined time synchronization of a shipborne large inertia antenna servo system, comprising the following steps:

[0008] Step 1, establish the dynamic model of the shipborne large inertia antenna servo system based on dual motor drive, and initialize the state and control parameters of the system;

[0009] Step 2, design a predetermined time disturbance observer to compensate for external unknown disturbances;

[0010] Step 3, design a non-singular scheduled time tracking controller to ensure that the load tracking error converges within a scheduled time;

[0011] Step 4, design a non-singular scheduled time synchronization controller to ensure that the dual motor synchronization error converges within the scheduled time and realizes the scheduled time synchronization control.

[0012] Further, the process of step 1 is as follows:

[0013] 1.1 The dynamics of the shipborne large inertia antenna servo system is expressed as:

[0014] (1);

[0015] in, , and are the angular position, angular velocity and angular acceleration of the load respectively; , and Respectively Angular position, angular velocity and angular acceleration of each motor; and are the rotational inertia of the load and the motor respectively; and are the friction coefficients at the load end and the motor end, respectively; Additional disturbances caused by sea waves and sea breezes, Additional disturbances caused by factors such as electromagnetic interference; To transmit torque; is the control input;

[0016] 1.2 According to formula (1), the angular acceleration of the load and the motor is:

[0017] (2);

[0018] 1.3 Defining state variables , formula (2) can be rewritten into the following state equation:

[0019] (3);

[0020] (4);

[0021] in, Respectively The first derivative of ; is a state variable , which is also the virtual control input of formula (3); , ; , .

[0022] Furthermore, in step 2, for equations (3) and (4), a predetermined time disturbance observer is designed to compensate for external unknown interference, and the process is as follows:

[0023] 2.1 According to equations (3) and (4), we get the following estimation model:

[0024] (5);

[0025] (6);

[0026] in, Respectively An estimated value of Respectively The first derivative of ;

[0027] 2.2 Definition of state observation error and , according to formula (3), formula (4), formula (5) and formula (6), its derivative is:

[0028] (7);

[0029] in, It is unknown interference from the outside world Estimation error, and according to formula (7) The convergence of The convergence of is consistent;

[0030] 2.3 According to equations (5) and (6), design the scheduled time disturbance observer:

[0031] (8);

[0032] (9);

[0033] in, , , , , are all normal numbers, , and is the time constant, Represents a symbolic function.

[0034] Furthermore, the process of step 3 is as follows:

[0035] 3.1 Define the following tracking error:

[0036] (10);

[0037] in, represents the expected tracking trajectory;

[0038] 3.2 According to formula (10), the following non-singular predetermined time sliding surface is designed:

[0039] (11);

[0040] in, express The first derivative of , , is a constant, is the time constant;

[0041] 3.3 Deriving equation (11), and substituting equation (3) and equation (10) into it, we obtain:

[0042] (12);

[0043] 3.4 According to equation (12), the following non-singular scheduled time tracking controller is designed to ensure that the tracking error converges within the scheduled time:

[0044] (13);

[0045] in, , , is a constant, is the time constant, for The second derivative of .

[0046] The process of step 4 is as follows:

[0047] 4.1 The virtual control input obtained by equation (13) Substituting into the following tracking differentiator,

[0048] (14);

[0049] in, and They are and The estimated value of Respectively The first derivative of All are normal numbers;

[0050] 4.2 According to equation (14), the synchronization error is defined as follows:

[0051] (15);

[0052] in, and All are normal numbers;

[0053] 4.3 Based on the synchronization error defined in equation (15), the following non-singular predetermined time sliding surface is designed:

[0054] (16);

[0055] in, express The first derivative of , , is a constant, is the time constant;

[0056] 4.4 Deriving equation (16), and substituting equation (4) and equation (15) into it, we obtain:

[0057] (17);

[0058] 4.5 According to equation (17), the following non-singular scheduled time synchronization controller is designed to ensure that the synchronization error converges within the scheduled time:

[0059] (18);

[0060] in, , , is a constant, is the time constant, for The first derivative of .

[0061] The present invention designs a predetermined time synchronization control method for a shipborne large inertia antenna servo system. The proposed predetermined time disturbance observer can quickly estimate and compensate for external interferences such as sea wind and waves, and designs a non-singular predetermined time synchronization and tracking controller, thereby improving the anti-interference performance of the system and the convergence speed of synchronization and tracking errors, avoiding controller singularity, reducing calculation complexity, and realizing the shipborne large inertia antenna servo system to accurately track the expected trajectory within a preset time.

[0062] The technical concept of the present invention is: in view of the fact that the shipborne large inertia antenna servo system is susceptible to external interference such as sea wind and waves, a predetermined time disturbance observer is designed to quickly estimate and compensate for external interference, and to ensure that the upper limit of the minimum convergence time of the observation error can be explicitly contained in an adjustable parameter, which can be set in advance according to actual needs. In addition, a non-singular predetermined time synchronization and tracking controller is designed to avoid controller singularity, reduce computational complexity, and realize the predetermined time synchronization and tracking control of the shipborne large inertia antenna servo system.

[0063] The effective effects of the present invention are: realizing the predetermined time estimation and compensation of external interferences such as sea wind and waves, avoiding controller singularity, reducing calculation complexity, and realizing the predetermined time synchronization and tracking control of the shipborne large inertia antenna servo system. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is a control flow chart of the present invention;

[0065] Figure 2 It is the load angle position tracking effect;

[0066] Figure 3 For the motor synchronization effect;

[0067] Figure 4 To estimate the effect of external interference;

[0068] Figure 5 is the control input signal. DETAILED DESCRIPTION

[0069] The present invention will be further described below in conjunction with the accompanying drawings.

[0070] Reference Figure 1~Figure 5 , a method for pre-setting time synchronization control of a shipborne large inertia antenna servo system, comprising the following steps:

[0071] Step 1: Establish the dynamic model of the shipborne large inertia antenna servo system based on dual motor drive and initialize the state and control parameters of the system. The process is as follows:

[0072] 1.1 The dynamics of the shipborne large inertia antenna servo system is expressed as:

[0073] (1);

[0074] in, , and are the angular position, angular velocity and angular acceleration of the load respectively; , and Respectively Angular position, angular velocity and angular acceleration of each motor; and are the rotational inertia of the load and the motor respectively; and are the friction coefficients at the load end and the motor end, respectively; Additional disturbances caused by sea waves and sea breezes, Additional disturbances caused by factors such as electromagnetic interference; To transmit torque; is the control input;

[0075] 1.2 According to formula (1), the angular acceleration of the load and the motor is:

[0076] (2);

[0077] 1.3 Defining state variables , formula (2) can be rewritten into the following state equation:

[0078] (3);

[0079] (4);

[0080] in, Respectively The first derivative of ; is a state variable , which is also the virtual control input of formula (3); , ; , ;

[0081] Step 2: Based on equations (3) and (4), a predetermined time disturbance observer is designed to compensate for external unknown disturbances. The process is as follows:

[0082] 2.1 According to equations (3) and (4), we get the following estimation model:

[0083] (5);

[0084] (6);

[0085] in, Respectively An estimated value of Respectively The first derivative of ;

[0086] 2.2 Definition of state observation error and , according to formula (3), formula (4), formula (5) and formula (6), its derivative is:

[0087] (7);

[0088] in, It is unknown interference from the outside world Estimation error, and according to formula (7) The convergence of The convergence of is consistent;

[0089] 2.3 According to equations (5) and (6), design the scheduled time disturbance observer:

[0090] (8);

[0091] (9);

[0092] in, , , , , are all normal numbers, , and is the time constant, represents a symbolic function;

[0093] Step 3: Design a non-singular scheduled time tracking controller to ensure that the load tracking error converges within the scheduled time. The process is as follows:

[0094] 3.1 Define the following tracking error:

[0095] (10);

[0096] in, represents the expected tracking trajectory;

[0097] 3.2 According to formula (10), the following non-singular predetermined time sliding surface is designed:

[0098] (11);

[0099] in, express The first derivative of , , is a constant, is the time constant;

[0100] 3.3 Deriving equation (11), and substituting equation (3) and equation (10) into it, we obtain:

[0101] (12);

[0102] 3.4 According to equation (12), the following non-singular scheduled time tracking controller is designed to ensure that the tracking error converges within the scheduled time:

[0103] (13);

[0104] in, , , is a constant, is the time constant, for The second derivative of

[0105] Step 4: Design a non-singular scheduled time synchronization controller to ensure that the dual motor synchronization error converges within the scheduled time. The process is as follows:

[0106] 4.1 The virtual control input obtained by equation (13) Substituting into the following tracking differentiator,

[0107] (14);

[0108] in, and They are and The estimated value of Respectively The first derivative of All are normal numbers;

[0109] 4.2 According to equation (14), the synchronization error is defined as follows:

[0110] (15);

[0111] in, and All are normal numbers;

[0112] 4.3 Based on the synchronization error defined in equation (15), the following non-singular predetermined time sliding surface is designed:

[0113] (16);

[0114] in, express The first derivative of , , is a constant, is the time constant;

[0115] 4.4 Deriving equation (16), and substituting equation (4) and equation (15) into it, we obtain:

[0116] (17);

[0117] 4.5 According to equation (17), the following non-singular scheduled time synchronization controller is designed to ensure that the synchronization error converges within the scheduled time:

[0118] (18);

[0119] in, , , is a constant, is the time constant, for The first derivative of .

[0120] To verify the effectiveness of the proposed method, the present invention conducted a simulation experiment on the control effect shown in formula (18). The initial conditions and control parameters in the experiment were set as follows: the sampling step was 0.001s; the predetermined time disturbance observer parameter was selected as ; The differential tracker parameters are ; The parameters of the non-singular scheduled time synchronization and tracking controller are The expected tracking trajectory is .

[0121] Figure 2-Figure 5 This is the experimental result diagram of the proposed method for the scheduled time synchronization control of the shipborne large inertia antenna servo system. Figure 2 This is the load angular position tracking effect diagram. It can be seen from the figure that the load tracks the expected signal at about 0.2s, and then it matches the expected tracking signal well. Figure 3 are the angular position synchronization signals and synchronization error signals of the two motors. It can be seen from the figure that the motor synchronization error converges to near 0 within 0.5s; Figure 4 It is the observation effect of the disturbance observer. It can be seen from the figure that the disturbance observer can quickly and accurately estimate the external disturbance; Figure 5 It is the control input signal. It can be seen from the figure that the control signal is initially large, enters a steady state after 0.5s, and fluctuates periodically around 0. In summary, the scheduled time synchronization control method for the shipborne large inertia antenna servo system can quickly and accurately compensate for the influence of external interference on the control accuracy of the shipborne large inertia antenna servo system, avoid controller singularity, reduce computational complexity, and realize the scheduled time synchronization and tracking control of the shipborne large inertia antenna servo system.

[0122] The above is an experiment given by the present invention to show the superiority of the designed method. Obviously, the present invention is not limited to the above examples, and various modifications can be made to it without departing from the basic spirit of the present invention and not exceeding the scope of the essential content of the present invention. The control method designed by the present invention has a good control effect on the shipborne large inertia antenna servo system tracking the desired trajectory in the presence of external interference, and can effectively improve the control accuracy and rapidity of the shipborne large inertia antenna servo system.

Claims

1. A method for controlling the predetermined time synchronization of a shipborne large inertia antenna servo system, characterized in that: The method comprises the following steps: Step 1, establish a dynamic model of the shipborne large inertia antenna servo system based on dual motor drive, and initialize the state and control parameters of the system; Step 2, design a predetermined time disturbance observer to compensate for external unknown disturbances; Step 3, design a non-singular scheduled time tracking controller to ensure that the load tracking error converges within a scheduled time; Step 4, design a non-singular scheduled time synchronization controller to ensure that the dual motor synchronization error converges within a scheduled time, thereby achieving scheduled time synchronization control; The process of step 1 is as follows: 1.1 The dynamics of the shipborne large inertia antenna servo system is expressed as: (1)； in, , and are the angular position, angular velocity and angular acceleration of the load respectively; , and Respectively Angular position, angular velocity and angular acceleration of each motor; and are the rotational inertia of the load and the motor respectively; and are the friction coefficients at the load end and the motor end, respectively; Additional disturbances caused by sea waves and sea breezes, Additional disturbances caused by factors such as electromagnetic interference; To transmit torque; is the control input; 1.2 According to formula (1), the angular acceleration of the load and the motor is: (2)； 1.3 Defining state variables , formula (2) can be rewritten into the following state equation: (3)； (4)； in, Respectively The first derivative of ; is a state variable , which is also the virtual control input of formula (3); , ; , ; In step 2, for equations (3) and (4), a predetermined time disturbance observer is designed to compensate for external unknown disturbances. The process is as follows: 2.1 According to equations (3) and (4), we get the following estimation model: (5)； (6)； in, Respectively An estimated value of Respectively The first derivative of ; 2.2 Definition of state observation error and , according to formula (3), formula (4), formula (5) and formula (6), its derivative is: (7)； in, It is unknown interference from the outside world Estimation error, and according to formula (7) The convergence of The convergence of is consistent; 2.3 According to equations (5) and (6), design the scheduled time disturbance observer: (8)； (9)； in, , , , , are all normal numbers, , and is the time constant, represents a symbolic function; The process of step 3 is as follows: 3.1 Define the following tracking error: (10)； in, represents the expected tracking trajectory; 3.2 According to formula (10), the following non-singular predetermined time sliding surface is designed: (11)； in, express The first derivative of , , is a constant, is the time constant; 3.3 Deriving equation (11), and substituting equation (3) and equation (10) into it, we obtain: (12)； 3.4 According to equation (12), the following non-singular scheduled time tracking controller is designed to ensure that the tracking error converges within the scheduled time: (13)； in, , , is a constant, is the time constant, for The second derivative of The process of step 4 is as follows: 4.1 The virtual control input obtained by equation (13) Substituting into the following tracking differentiator, (14)； in, and They are and The estimated value of Respectively The first derivative of All are normal numbers; 4.2 According to equation (14), the synchronization error is defined as follows: (15)； in, and All are normal numbers; 4.3 Based on the synchronization error defined in equation (15), the following non-singular predetermined time sliding surface is designed: (16)； in, express The first derivative of , , is a constant, is the time constant; 4.4 Deriving equation (16), and substituting equation (4) and equation (15) into it, we obtain: (17)； 4.5 According to equation (17), the following non-singular scheduled time synchronization controller is designed to ensure that the synchronization error converges within the scheduled time: (18)； in, , , is a constant, is the time constant, for The first derivative of .

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