A nonlinear multi-mode adaptive intelligent control method for large-angle turning

Abstract

The present application relates to a nonlinear multi-mode adaptive intelligent control method for large angle slewing in the field of radio tracking measurement, comprising the following steps: obtaining the maximum speed, maximum acceleration and speed loop gain parameters of measurement; calculating the antenna large angle slewing error, and using the last position loop regulator output speed to calculate the current position loop regulator output speed U n ; calculating the descending section position loop output speed value U d according to the antenna actual maximum speed, speed loop gain and antenna large angle slewing error; comparing the sizes of U d and U n ; if U n is greater than or equal to U d , then U d is assigned to U n ; if U n is less than U d , then the value of U n remains unchanged; calculating the gain control output U pi in the digital PI controller; comparing the sizes of the descending section position loop output speed value U d and the value of U pi ; if U d is greater than or equal to U pi , then U pi is assigned to U n ; if U d is less than the value of U pi , then the value of U n remains unchanged. The present application avoids excessive acceleration / deceleration, reduces the impact on the antenna transmission mechanism, and improves the service life of the antenna.

Description

TECHNICAL FIELD

[0001] The present application relates to a large angle turning nonlinear multimode adaptive intelligent control method in the field of radio tracking measurement, in particular to a large angle turning of an antenna control "steady, fast and accurate" realized by a nonlinear multimode adaptive controller. BACKGROUND

[0002] In a multi-task, multi-target large radio tracking measurement antenna, the interval time of two or more tasks is very short, and the initial waiting position angle of the antenna needs to be turned by a large angle. In order to ensure the smooth execution of the task and the safe and smooth operation of the large antenna, the primary task is to control the antenna position well.

[0003] The so-called well-controlled means: first, "steady", second, "fast", and third, "accurate". "Steady" means that the antenna speed runs smoothly, and the acceleration / deceleration process is smooth and continuous without overshoot (overshoot). "Fast" means that the acceleration potential of the antenna is fully utilized to position in the shortest time. "Accurate" means high positioning accuracy and small angle position error.

[0004] The conventional large angle turning control method adopts an incremental digital PID control algorithm, but in an actual servo system, the application of the incremental digital PID controller cannot well solve the contradiction between the stability and tracking performance of the system. The dynamic performance (overshoot, oscillation times, and regulation time) of the step response of the system is difficult to meet the requirements, and the antenna will produce overshoot during large angle turning, which will lengthen the target capture time.

[0005] In order to avoid overshoot and make the antenna run more smoothly, a multimode control algorithm is an effective way during large angle turning. In a multi-task, multi-target tracking system, the control requirements of the antenna position pointing can be well met. However, the control algorithm requires that the speed command of the system output itself cannot have a jump during speed switching and closed loop. How to realize the stable and undisturbed smooth transition of various modes is a difficulty in realizing the algorithm. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a large angle turning nonlinear multimode adaptive intelligent control method. The performance of the servo under the condition of the maximum speed and acceleration of the antenna is fully utilized, and linear and nonlinear control modes are used for time-sharing switching to realize fast, smooth and accurate positioning of the antenna, avoid excessive acceleration / deceleration, reduce the impact on the transmission mechanism of the antenna, and improve the service life of the antenna.

[0007] To achieve the above purpose, the technical scheme provided by the present application is as follows:

[0008] The application relates to a nonlinear multi-mode adaptive intelligent control method for large-angle turning, which is applied to an antenna servo control system and comprises the following steps:

[0009] S1: acquiring measured antenna motion characteristic parameters, including an antenna measured maximum speed V max , a maximum acceleration a max , a speed loop gain K rate and a sampling period T;

[0010] S2: calculating an antenna large-angle turning error AE and using a last position loop regulator output speed U n-1 to calculate a current position loop regulator output speed U n ;

[0011] S3: updating the value of the position loop regulator output U n according to the product of the maximum speed V max and the speed loop gain K rate , if the position loop regulator output U n is greater than or equal to the value of V max * K rate , then V max * K rate is assigned to U n , otherwise, -V max * K rate is assigned to U n ;

[0012] S4: calculating a descending section position loop output speed value U d according to the antenna measured maximum speed V max , the speed loop gain K rate and the antenna large-angle turning error AE, if the antenna large-angle turning error AE is less than 0, then U d takes an opposite number;

[0013] S5: comparing the size of U d and U n , if U n is greater than or equal to U d , then U d is assigned to U n ; if U n is less than U d , then the value of U n remains unchanged;

[0014] S6: calculating a gain control output in a digital PI controller:

[0015] U pi = K p * AE

[0016] K pTo adjust the direct current gain of the regulator;

[0017] S7: comparing the descending section position loop output speed value U d and U pi , if U d is greater than or equal to U pi , then U pi is assigned to U n , if U d is less than U pi , then the value of U n is unchanged.

[0018] In step S2, the following steps are performed:

[0019] calculating the large angle turning error DE = command angle - current angle;

[0020] if the large angle turning error DE is greater than or equal to 0, then the last position loop regulator output speed U n-1 is used to calculate the ascending section speed U n output by the current position loop regulator:

[0021] U n = U n-1 + a max * T * K rate ;

[0022] if the large angle turning error DE is less than 0, then the last position loop regulator output speed U n-1 is used to calculate the descending section speed U n output by the current position loop regulator:

[0023] U n = U n-1 - a max * T * K rate .

[0024] In step S4, the descending section position loop output speed value U d is calculated as follows:

[0025]

[0026] From the above description, it can be seen that the present application has the following advantages compared with the prior art method:

[0027] (1) The present application realizes fast and smooth positioning control of the antenna through linear and nonlinear multiple control mode undisturbed time-sharing switching, which is simple and convenient for engineering application.

[0028] (2) The present application can effectively reduce the system overshoot, improve the system stability and not affect the steady-state error.

[0029] (3) The application can realize one-time positioning control of large-angle rotation of the antenna, has high control precision, avoids excessive acceleration / deceleration, reduces impact on the antenna transmission mechanism, and improves the service life of the antenna.

[0030] (4) The application can plan the trajectory of large-angle rotation of the antenna, limit the maximum speed and maximum acceleration in the movement process of the antenna, and effectively avoid the influence of large movement characteristics on the closed-loop stability of the antenna.

[0031] (5) The application can realize a nonlinear multi-mode adaptive control algorithm in the antenna controller, which can be applied to other antenna servo control systems controlled by a digital computer, has strong applicability and high portability. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly describe the patent, a plurality of drawings are provided below, which are intended to assist in describing the background art, technical principles and certain specific embodiments of the patent. It should be noted that the drawings can or can not give some specific details which have been described in the text part of the patent and are common knowledge to those skilled in the art; and because those skilled in the art can certainly design more drawings based on the disclosed text and drawing contents of the patent without any creative labor, the following drawings can or can not cover all the technical solutions described in the text part of the patent.

[0033] Figure 1 The ideal large-angle rotation control curve for the application.

[0034] Figure 2 The ideal large-angle rotation nonlinear multi-mode adaptive control curve for the application - mode ① reaches the maximum speed.

[0035] Figure 3 The ideal large-angle rotation nonlinear multi-mode adaptive control curve for the application - mode ② does not reach the maximum speed.

[0036] Figure 4 The antenna servo loop diagram of the large-angle rotation nonlinear multi-mode adaptive control of the application.

[0037] Figure 5 The large-angle rotation nonlinear multi-mode adaptive intelligent control flowchart of the application.

[0038] Figure 6 The 100° angle rotation operation curve diagram of the application; the angle position recording period is 10 ms.

[0039] Figure 7 The rotation speed operation curve diagram of the application; the angle position recording period is 10 ms.

[0040] Figure 8 The rotation acceleration operation graph of the application; the angle position recording period is 10 ms. DETAILED DESCRIPTION

[0041] The application will be described below in combination with the drawings and specific embodiments:

[0042] ATTACHMENT Figure 1 The output speed, acceleration, and position control curves of the ideal large-angle slewing of the antenna control system are given, Figure 1 The curve ① is the uniform acceleration stage, the curve ② is the constant speed stage, and the curve ③ is the straight line uniform deceleration stage, while the antenna control curve of the large-angle slewing realized by the nonlinear multi-mode control mode algorithm of the application is Figure 2 or Figure 3 as shown, Figure 2 The curve ④ is added in the position closed loop stage, and the curve ③ is the parabolic uniform deceleration stage; Figure 3 The operation curve in which the maximum speed is not reached is shown in the figure, and only the uniform acceleration curve ①, the uniform deceleration curve ②, and the position closed loop stage curve ③ are shown.

[0043] ATTACHMENT Figure 4 The figure is the antenna servo control system loop diagram of the large-angle slewing nonlinear multi-mode control mode algorithm, which includes the current loop, the speed loop, and the position loop.

[0044] ATTACHMENT Figure 5 The figure is the flow chart of the large-angle slewing nonlinear multi-mode adaptive intelligent control method.

[0045] The large-angle slewing nonlinear multi-mode adaptive intelligent control method in the embodiment adopts the following steps:

[0046] According to the measured maximum speed V max of the antenna = 20° / s, the maximum acceleration a max = 10° / s 2 , the speed loop gain K rate = 2, and the sampling period T = 10 ms;

[0047] S1: Load the parameters such as the measured maximum speed V max of the antenna, the maximum acceleration a max , the speed loop gain K rate , and the sampling period T;

[0048] S2: Calculate the large-angle slewing error ΔE of the antenna = command angle - current angle; judge whether the large-angle slewing error ΔE is greater than or equal to 0; if the large-angle slewing error is greater than or equal to 0, calculate the rising section speed U n-1 using the last position loop regulator output speed U n :

[0049] Position loop output U n = last position loop output U n-1 + maximum acceleration a max × sampling period T × velocity loop gain K rate ;

[0050] If large angle turning error is less than 0, then use last position loop regulator output velocity U n-1 to calculate downlink velocity U n :

[0051] Position loop output U n = last position loop output U n-1 - maximum acceleration a max × sampling period T × velocity loop gain K rate ;

[0052] S3: According to maximum velocity and velocity loop gain, calculate V max × K rate value, judge whether U n is greater than or equal to V max × K rate value, if U n ≥ V max × K rate , then U n = V max × K rate ; if U n < V max × K rate , then U n = -V max × K rate ;

[0053] S4: Calculate downlink position loop output velocity value U d , if antenna large angle turning error ΔE is less than 0, then U d take opposite number U d = -U d ;

[0054]

[0055] S5: Compare the size of U d and U n , if U n is greater than or equal to U d , then assign U d to U n ; if U n is less than U d , then U n value is unchanged;

[0056] S6: Calculate the output of only gain control in digital PI controller:

[0057] U pi = K p × ΔE

[0058] S7: Compare the size of the descending section position loop output speed value U d and U pi value, if U d is greater than or equal to U pi , U pi is assigned to U n , if U d is less than U pi value, U n value is unchanged.

[0059] S8: Determine whether the antenna large angle turning error ΔE is less than or equal to 0.1°, if less than or equal to 0.1°, the position loop output value adopts the output value of the digital PID controller fused with first order inertia link; if greater than 0.1°, the position loop integral value is cleared;

[0060] Digital PID controller fused with first order inertia link: an improved control algorithm is designed on the basis of PID algorithm, a first order inertia link is connected in series in the PID correction link to prevent resonance, so that the characteristics of the tracking system will be improved, the tracking system resonance is prevented, the tracking system bandwidth is improved, because this method changes the slope of the amplitude frequency characteristic of the tracking system loop, the tracking system resonance peak is lowered, the tracking system amplitude margin is increased, the phase margin is reduced, and the system dynamic characteristic quality is improved. Thus, when the input deviation rate is large, the output of the tracking system can be effectively controlled, and the system quality is adjusted.

[0061] The transfer function of the first order inertia link is:

[0062] G f (S) = 1 / (T f S + 1) (1)

[0063] In the formula: T f is the time constant of inertia link;

[0064] The transfer function of the standard PID regulation rule is:

[0065]

[0066] In the formula: K p is the proportional coefficient, T i is the integral coefficient, and T d is the differential coefficient.

[0067] Combining both formula (1) and (2) can form a new improved PID control algorithm:

[0068]

[0069] The improved PID digital controller Z-domain transfer function is obtained by discretization:

[0070] U k = AU (k－1) + BU (k－2) + CE k + DE k-1 + EE k-2 (4)

[0071] In the formula:

[0072]

[0073]

[0074]

[0075]

[0076] In the formula:

[0077] T is the sampling period, T i is the regulator integral coefficient, U (k) is the current control amount (regulator current output), U (k－1) is the last control amount (regulator previous output), E k is the regulator current input, E (k－1) is the regulator previous input, E (k－2) is the regulator last-but-one input.

[0078] Formula (4) is the mathematical algorithm model when programming on the ACU. E k , E (k－1) , E (k－2) is the angular error, U (k) , U (k－1) is the speed command. The above parameters can be calculated in MATLAB, and then the parameters are brought into the formula when programming, which is convenient, simple and easy to implement.

[0079] S9: The position loop output value is subjected to speed command limiting processing;

[0080] S10: The current position loop output speed is assigned to the last position loop output;

[0081] S11: send the position loop output value to D / A, complete digital analog conversion, output speed value to speed input end.

[0082] By using the large-angle turning nonlinear multi-mode adaptive intelligent control algorithm of the application, 100° angle turning is realized, and a 100° turning curve is shown in Figure 6. Figure 6 A maximum speed curve of the antenna is shown in Figure 7. Figure 7 A maximum angular acceleration curve of the antenna is shown in Figure 8. Figure 8

[0083] The above merely describes the best mode of the application, but the protection scope of the application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered in the protection scope of the application.

[0084] The contents not described in detail in the specification of the application belong to the common knowledge of the skilled in the art.​

Claims

1. A nonlinear multi-mode adaptive intelligent control method for large angle maneuvering, characterized in that, Applicable to antenna servo control system, comprising the following steps: S1: Obtain measured antenna motion characteristic parameters, including antenna measured maximum speed V max , maximum acceleration a max , speed loop gain K rate , and sampling period T; S2: Calculate the large angle steering error of the antenna DE, and use the last position loop regulator output speed U n-1 Calculate the current position loop regulator output speed U n ; S3: The value of the position loop regulator output U is updated by the product of the maximum speed V and the speed loop gain K max rate n n max rate max rate n max rate n ;​​​​​​​​​​​ S4: Calculate the antenna actual maximum speed V max , the velocity loop gain K rate and the antenna large angle turning error ΔE to calculate the falling section position loop output speed value U d If the antenna large angle turning error ΔE is less than 0, U d takes the opposite number; S5: compare U d and U n , if U n is greater than or equal to U d , then assign U d to U n ; if U n is less than U d , then U n is unchanged; S6: calculate the gain control output in the digital PI controller: U pi = K p × ΔE K p To adjust the DC gain of the regulator; S7: compare the descending section position loop output speed value U d and U pi value, if U d is greater than or equal to U pi , then U pi is assigned to U n , if U d is less than U pi value, then U n value remains unchanged.

2. A nonlinear multimode adaptive intelligent control method for large angle turning according to the previous claim 1, characterized by, Step S2 is specifically: Calculate the large angle turning error of the antenna ΔE = command angle - current angle; If the large angle turning error DE is greater than or equal to 0, the last position loop regulator output velocity U is used n-1 The rising section velocity U of the current position loop regulator output is calculated n : U n = U n-1 + a max x T x K rate ; If the large angle turn error DE is less than 0, the last position loop regulator output velocity U is used n-1 The falling segment velocity U of the current position loop regulator output is calculated n : U n = U n-1 - a max x T x K rate .

3. A nonlinear multimode adaptive intelligent control method for large angle turning according to the previous claim 1, characterized in that, The position loop output speed value U in the falling section in step S4 d is calculated as follows:

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