An anti-interference control method for decoupling tracking and stabilization performance of airborne optoelectronic system

Abstract

The present invention provides an anti-interference control method for decoupling the tracking and stabilization performance of an airborne optoelectronic system, and belongs to the field of automatic control technology. The method comprises: establishing a dynamic model of a fast reflector driven by piezoelectric ceramics; designing an extended state observer according to the order of the dynamic model of the fast reflector, constructing a correction term using the output of the sensor and the error between the output of the extended state observer, and obtaining a corrected observer equation; designing a pointing controller for driving the fast reflector of the optoelectronic tracking system based on the corrected observer equation; obtaining the two-degree-of-freedom transfer functions of command tracking and disturbance suppression based on the designed pointing controller through a closed-loop structure derivation, and analyzing the relationship between the performance of the two and the control and observation parameters. The present invention can improve the command tracking and disturbance suppression performances at the same time by decoupling the command tracking and disturbance suppression performances, and realize fast response and high-precision control of the piezoelectric driven fast reflector.

Description

Technical Field

[0001] The invention belongs to the technical field of automatic control, and in particular relates to an anti-interference control method for decoupling tracking and stabilization performance of an airborne optoelectronic system. Background Art

[0002] The pointing stability of the airborne optoelectronic tracking system is reflected in two aspects: 1) controlling the aiming line of the optoelectronic system to always remain on the observed target, that is, command tracking; 2) eliminating the unwanted movement of the pointing mechanism including the fast reflector in the inertial space, that is, disturbance suppression.

[0003] However, in the existing dual-degree-of-freedom anti-disturbance control, including self-disturbance rejection control and disturbance observer-based control (patent application number CN202211130669.3), the command tracking and disturbance suppression transfer functions are related to the same parameters, which means that the performance of both is affected by the same parameters, and there is coupling between command tracking and disturbance suppression. The disadvantages of the coupling characteristic are: 1) It makes it difficult to improve the command tracking and disturbance suppression performance at the same time; 2) For the pointing stability of the optoelectronic tracking system or other practical applications, it is difficult to balance the two performance requirements and it is difficult to quickly and easily achieve parameter tuning. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an anti-interference control method for decoupling the tracking and stability performance of an airborne optoelectronic system, which uses the speed measurement information in the optoelectronic tracking system to construct an observation compensation structure to reduce the conservatism of the system. The corrected disturbance observer output is used to design a proportional differential control law, which realizes the decoupling of command tracking and disturbance suppression performance, and can simultaneously improve the response speed and stability accuracy of the piezoelectric driven fast reflector pointing mechanism.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The first step is to establish the dynamic model of the fast mirror driven by piezoelectric ceramics and the transfer function between the input voltage and output displacement of the fast mirror;

[0007] The second step is to design an extended state observer according to the order of the fast reflector dynamics model established in the first step, and measure the angular velocity of the fast reflector through a gyroscope or a photoelectric encoder sensor to correct the output of the extended state observer;

[0008] The third step is to design the fine loop pointing controller of the optoelectronic tracking system based on the output of the modified extended state observer.

[0009] The fourth step is to obtain the two-degree-of-freedom transfer function of command tracking and disturbance suppression through closed-loop structure analysis based on the fine loop pointing controller of the optoelectronic tracking system, so that command tracking and disturbance suppression can be independently adjusted according to the control and observation bandwidths, and command tracking and stability performance can be completely decoupled.

[0010] The advantages of the present invention compared with the prior art are:

[0011] (1) The present invention can improve both command tracking and disturbance suppression performance by independently adjusting control and observation parameters, and can achieve fast response and high-precision control of the piezoelectric driven fast reflector.

[0012] (2) Since the command tracking and disturbance suppression performances are decoupled in the present invention, there is no need to select or design a compromise between the two performances, which makes the setting of control and observation parameters simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flowchart of an anti-interference control method for decoupling tracking and stabilization performance of an airborne optoelectronic system according to the present invention;

[0014] Figure 2 This is the anti-interference control structure diagram of the piezoelectric driven fast reflection mirror;

[0015] Figure 3 Comparison diagram of the estimation errors of the extended state observer and the corrected observer under sinusoidal disturbance;

[0016] Figure 4 This is a partial enlarged diagram of the comparison of the estimation errors of the extended state observer and the corrected observer under sinusoidal disturbance;

[0017] Figure 5 A comparison diagram of the output response based on the active disturbance rejection control and the present invention;

[0018] Figure 6 This is a comparison chart of the output response of the ADRC under the change of control bandwidth;

[0019] Figure 7 To control bandwidth changes, a response comparison diagram is output based on the present invention.

[0020] Figure 8 This is a comparison chart of the output response of the active disturbance rejection control under the change of observation bandwidth;

[0021] Fig. 9 The output response comparison diagram based on the present invention is shown in FIG. 1 under the observation bandwidth change. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1 As shown, the specific implementation steps of the present invention are as follows:

[0024] The first step is to establish the dynamic model of the fast mirror driven by piezoelectric ceramics and the transfer function between the input voltage and output displacement of the fast mirror;

[0025] The dynamic model of the piezoelectric ceramic driven fast reflector is established as , where F represents the output driving force of the piezoelectric ceramic, m represents the mass of the fast reflector, x represents the deformation of the piezoelectric ceramic, and t represents the time. They represent the first and second order derivatives of the deformation of the piezoelectric ceramic over time, K d Represents the damping coefficient of piezoelectric ceramics, K s represents the stiffness coefficient of piezoelectric ceramics, d represents the unknown uncertain disturbance of the system, including external disturbance, nonlinear unmodeled dynamics and parameter perturbation;

[0026] The voltage balance equation of piezoelectric ceramics is: , where u represents the voltage control law applied to the piezoelectric ceramic, K p represents the inverse piezoelectric effect coefficient;

[0027] Substituting the voltage balance equation of piezoelectric ceramics into the dynamic model of the fast reflector driven by piezoelectric ceramics and performing Laplace transform, the transfer function G between the input voltage and output displacement of the fast reflector is obtained. m (s):

[0028] ,

[0029] Wherein, s represents the Laplace operator, x(s) represents the Laplace transformation of the deformation of the piezoelectric ceramic, and u(s) represents the Laplace transformation of the voltage control law applied to the piezoelectric ceramic.

[0030] The second step is to design an extended state observer according to the order of the fast reflector dynamics model established in the first step, and measure the angular velocity of the fast reflector through a gyroscope or a photoelectric encoder sensor to correct the output of the extended state observer;

[0031] The dynamic model of the piezoelectric ceramic driven fast mirror is rewritten as the integrator series standard model , where the control gain , the total disturbance represents the sum of the internal dynamics and external disturbances that are different from the integrator, and is considered as the expanded state of the system, represents the first-order derivative of the deformation of the piezoelectric ceramic, then the state equation of the integrator series standard form of the piezoelectric ceramic driven fast reflector dynamic model is:

[0032] ,

[0033] in, represents the output of the fast mirror, represents the rate of change of the output, Indicates the system expansion state, represents the rate of change of the total disturbance, The total disturbance The first derivative of represents the first-order derivative of the system's expansion state, The outputs of the fast mirrors are , the rate of change of output , system expansion state The first derivative of ;

[0034] Design the extended state observer:

[0035] ,

[0036] In the formula, are the estimates of the system state by the extended state observer, They are the estimates of the system state by the extended state observer The first derivative of They are the estimates of the system state by the extended state observer The gain, represents the estimated error of the system output;

[0037] The photoelectric tracking system is internally integrated with a gyro sensor that can measure the system output derivative, that is, the angular velocity information. However, the extended state observer only uses the system output, that is, the measurement information of the angular position, which is conservative. Therefore, the following observation compensation structure is designed:

[0038] ,

[0039] In the formula, They are the estimates of the system state by the extended state observer The correction item, It represents the output of the extended state observer after the estimated correction term, and the superscript T represents the transpose of the matrix.

[0040] The third step is to design the fine loop pointing controller of the optoelectronic tracking system based on the output of the modified extended state observer.

[0041] Based on the output of the extended state observer after the estimated correction term, the voltage control law of the piezoelectric ceramic driven fast reflector of the optoelectronic tracking system is designed, that is, the voltage control law applied to the piezoelectric ceramic :

[0042] ,

[0043] In the formula, is the gain of the fine loop pointing controller of the optoelectronic tracking system, represent the reference instruction, the first-order derivative of the reference instruction, and the second-order derivative of the reference instruction respectively.

[0044] The fourth step is to obtain the two-degree-of-freedom transfer function of command tracking and disturbance suppression through closed-loop structure analysis based on the fine loop pointing controller of the optoelectronic tracking system, so that command tracking and disturbance suppression can be independently adjusted according to the control and observation bandwidths, and command tracking and stability performance can be completely decoupled.

[0045] Performing Laplace transform on the extended state observer, the estimated output transfer function is:

[0046] ,

[0047] After the extended state observer estimates the correction term, the estimated output transfer function is:

[0048] ,

[0049] Substitute the estimated output transfer function after the extended state observer estimation correction term into the formula of the voltage control law of the piezoelectric ceramic driven fast reflector of the optoelectronic tracking system to obtain the voltage control law applied to the piezoelectric ceramic With reference instruction , the transfer function relationship between the system output x:

[0050]

[0051] Combining the state equation of the piezoelectric driven fast mirror integrator series dynamics model, the command tracking transfer function G is obtained. r (s) and the disturbance rejection transfer function G f (s) are:

[0052] ,

[0053] In the formula, represents the Laplace transform of the reference instruction, The Laplace transform of the system expansion state representing the total disturbance, when the first-order derivative of the reference command and the second-order derivative of the reference command r2 and r3 are not used, the command tracking transfer function G r (s) degenerates into:

[0054] .

[0055] In the formula, Represents the degraded instruction trace transfer function.

[0056] As you can see, G f (s) is only related to the parameter β in the modified disturbance observer, It is only related to the parameter k in the control law formula of the voltage applied to the piezoelectric ceramic, that is, the command tracking performance is only related to the controller gain Related, with the estimated gain It is irrelevant; the disturbance rejection performance is only related to the estimated gain Related to the controller gain Not relevant.

[0057] Example

[0058] In simulation, set the angular velocity value , the parameters are set to , the interference is set to a sinusoidal signal, and the occurrence time is 30s later, , simulation time is 50s, sampling step is 0.001s.

[0059] Figure 2 The control structure block diagram of the piezoelectric driven fast reflector of the airborne optoelectronic system is given, which includes the fast reflector system model, the controller and the corrected observer.

[0060] Figure 3 and Figure 4 The estimation effects of the two observers are demonstrated. Under the same observation bandwidth setting, the estimation error of the extended state observer is on the order of 200, while the estimation error of the corrected disturbance observer is less than 0.02, which is a huge difference.

[0061] Figure 5 The output response results of the ADRC and the control method proposed in this invention are compared. Under the same control bandwidth setting, the response time of the ADRC is close to 9s, while the proposed method achieves command following in less than 0.02s. In addition, it can be seen from the enlarged figure that the proposed control method has a stronger suppression effect on sinusoidal disturbances. Under the same controller design and parameter selection, the reason is that the modified observer estimates the sinusoidal disturbance more accurately.

[0062] Figure 6The output response results of the ADRC under different control parameters are compared. The change of control bandwidth not only affects the command tracking performance but also the disturbance suppression performance. Figure 7 The output response comparison of the proposed control method under different control bandwidths is given, ω c When the value increases from 40 to 50, the system response speed increases, but the disturbance suppression effect remains almost unchanged (10 -13 Magnitude errors fall within the range of calculation errors).

[0063] Figure 8 The output response results of ADRC pointing system under different observation parameters are compared. Fig. 9 The output response comparison of the proposed control method under different observation bandwidths is given, ω o Increasing from 600 to 650, the system disturbance suppression effect is enhanced, but the response speed, that is, the command tracking performance, remains almost unchanged.

[0064] comprehensive Figure 7 and Fig. 9 The simulation results verify that the designed anti-interference control method can achieve complete decoupling of command tracking and disturbance suppression performance.

[0065] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An anti-interference control method for decoupling the tracking and stabilization performance of an airborne optoelectronic system, characterized in that: The following steps are involved: The first step is to establish the dynamic model of the fast mirror driven by piezoelectric ceramics and the transfer function between the input voltage and output displacement of the fast mirror; The second step is to design an extended state observer according to the order of the fast reflector dynamics model established in the first step, and measure the angular velocity of the fast reflector through a gyroscope or a photoelectric encoder sensor to correct the output of the extended state observer; The third step is to design the fine loop pointing controller of the optoelectronic tracking system based on the output of the modified extended state observer. The fourth step is to obtain the two-degree-of-freedom transfer function of command tracking and disturbance suppression based on the fine loop pointing controller of the optoelectronic tracking system through closed-loop structure analysis, so that command tracking and disturbance suppression can be adjusted independently according to the control and observation bandwidths, and command tracking and stability performance can be completely decoupled. The first step is specifically implemented as follows: The dynamic model of the piezoelectric ceramic driven fast reflector is established as , where F represents the output driving force of the piezoelectric ceramic, m represents the mass of the fast reflector, x represents the deformation of the piezoelectric ceramic, and t represents the time. They represent the first and second order derivatives of the deformation of the piezoelectric ceramic over time, K d Represents the damping coefficient of piezoelectric ceramics, K s represents the stiffness coefficient of piezoelectric ceramics, d represents the unknown uncertain disturbance of the system, including external disturbance, nonlinear unmodeled dynamics and parameter perturbation; The voltage balance equation of piezoelectric ceramics is: , where u represents the voltage control law applied to the piezoelectric ceramic, K p represents the inverse piezoelectric effect coefficient; Substituting the voltage balance equation of piezoelectric ceramics into the dynamic model of the fast reflector driven by piezoelectric ceramics and performing Laplace transform, the transfer function G between the input voltage and output displacement of the fast reflector is obtained. m (s): ， Wherein, s represents the Laplace operator, x(s) represents the Laplace transformation of the deformation of the piezoelectric ceramic, and u(s) represents the Laplace transformation of the voltage control law applied to the piezoelectric ceramic; The second step is specifically implemented as follows: The dynamic model of the piezoelectric ceramic driven fast mirror is rewritten as the integrator series standard model , where the control gain , the total disturbance represents the sum of the internal dynamics and external disturbances that are different from the integrator, and is considered as the expanded state of the system, represents the first-order derivative of the deformation of the piezoelectric ceramic, then the state equation of the integrator series standard form of the piezoelectric ceramic driven fast reflector dynamic model is: ， in, represents the output of the fast mirror, represents the rate of change of the output, Indicates the system expansion state, represents the rate of change of the total disturbance, The total disturbance The first derivative of represents the first-order derivative of the system expansion state, The outputs of the fast mirrors are , the rate of change of output , system expansion state The first derivative of ; Design the extended state observer: ， In the formula, are the estimates of the system state by the extended state observer, They are the estimates of the system state by the extended state observer The first derivative of They are the estimates of the system state by the extended state observer The gain, represents the estimated error of the system output; Use the angular velocity to measure the rate of change of the output x2 and design the following extended state observer to estimate the correction term: ， In the formula, They are the estimates of the system state by the extended state observer The correction item, It represents the output of the extended state observer after the estimated correction term, and the superscript T represents the transpose of the matrix.

2. The anti-interference control method for decoupling the tracking and stabilization performance of an airborne optoelectronic system according to claim 1, characterized in that: The third step is specifically implemented as follows: Based on the output of the extended state observer after the estimated correction term, the voltage control law applied to the piezoelectric ceramic in the optoelectronic tracking system is designed. : ， In the formula, is the gain of the fine loop pointing controller of the optoelectronic tracking system, represent the reference instruction, the first-order derivative of the reference instruction, and the second-order derivative of the reference instruction respectively.

3. The anti-interference control method for decoupling the tracking and stabilization performance of an airborne optoelectronic system according to claim 1, characterized in that: The fourth step is specifically implemented as follows: Performing Laplace transform on the extended state observer, the estimated output transfer function is: ， After the extended state observer estimates the correction term, the estimated output transfer function is: ， Substitute the estimated output transfer function after the estimated correction term of the extended state observer into the photoelectric tracking system, and the voltage control law applied to the piezoelectric ceramic The voltage control law applied to the piezoelectric ceramic in the photoelectric tracking system is obtained from the formula With reference instruction , the transfer function relationship between the system output x: ， Combining the state equation of the piezoelectric driven fast mirror integrator series dynamics model, the command tracking transfer function G is obtained. r (s) and the disturbance rejection transfer function G f (s) are: ， In the formula, represents the Laplace transform of the reference instruction, The Laplace transform of the system expansion state representing the total disturbance, when the first-order derivative of the reference command and the second-order derivative of the reference command r2 and r3 are not used, the command tracking transfer function G r (s) degenerates into: ， In the formula, Represents the degraded instruction trace transfer function.

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