Research On Two-dimensional Piezoelectric Image Stabilization Platform And Its Contro

Piezoelectric actuators have the advantages of simple structure,anti-magnetic interference,high precision,fast response,high thrust,and low power consumption,and are widely used in precision driving,ultra-precision processing,biomedical,aerospace,and other fields.To cope with the problem that the imaging guidance system of infrared missiles faces the impact of large acceleration on the imaging quality,and to meet the requirements of fast response,overload resistance,high precision,and high stability of the image stabilization mechanism,the piezoelectric actuated lens stabilization technology and control method is proposed.A piezoelectric driven lens stabilization platform is designed to achieve high-precision,fastresponse perturbation compensation of the optical lens and improve the imaging quality and strike accuracy of guided weapons.The design method and motion characteristics of the one-dimensional bi-directional piezoelectric actuator are studied to reveal the amplification principle of the microdisplacement actuator and the hysteresis suppression characteristics of the bi-directional actuator;the dynamic and static modeling method and multi-variable optimization design method of the two-dimensional piezoelectric stabilized image platform are studied to explore the displacement output characteristics of the platform;the non-linear mathematical model of the piezoelectric hysteresis phenomenon is established,and the feed-forward control eliminates the hysteresis non-linearity;the closed-loop control loop is established.To further compensate for the piezoelectric hysteresis and coupling errors,feedback control is used to achieve high precision driving and resistance to random perturbation of the optical lens by the twodimensional piezoelectric stabilized image platform.The specific contents are arranged as follows.Taking the enhancement of missile strike accuracy as the research background,the more maturely developed Micro/Nano actuation technologies are introduced and the driving characteristics of different actuators are analyzed;the classification of piezoelectric precision driving technologies is developed,the characteristics and applications of three non-resonant piezoelectric actuators are discussed in detail,and the advantages of direct-drive piezoelectric actuators for guided weapon steadicam mechanisms are pointed out;three control methods are outlined for the hysteresis control problem,which three control methods are outlined,including feed-forward control,feedback control and feed-forward + feedback control.The piezoelectric effect,basic properties,parameters,and characteristics of piezoelectric stacks of piezoelectric materials are introduced;the characteristics,advantages,and disadvantages of different displacement amplification mechanisms are analyzed,and the structural design of one-dimensional piezoelectric actuators is carried out;the static mechanical model of the actuator is established based on the deformation energy method;the maximum driving stroke,maximum stress and resonance frequency of the actuator are analyzed by the finite element method;an experimental test platform is established to test the driving stroke of the actuator The actuator’s driving stroke reaches 91.45 μm,the coupling displacement is less than 3.72%,the displacement resolution reaches 35 nm,and the response time is stable within11-13 ms.Based on the bidirectional drive principle,the two-dimensional piezoelectric image stabilization platform is designed in conjunction with the image stabilization requirements,and the comprehensive performance of the two-dimensional piezoelectric image stabilization platform is improved through an intelligent optimization algorithm;its performance parameters are analyzed,an equivalent theoretical model is established based on the Castigliano’s second theorem and Lagrange’s equation,the analytical relationship between the displacement transfer coefficient and the structure size is derived,and parameters such as the displacement amplification ratio and the intrinsic frequency are also considered;the parameters are optimized through a genetic algorithm to achieve a high displacement The two-dimensional piezoelectric steadicam platform with high displacement transfer coefficient and low hysteresis performance is optimally designed by genetic algorithm;an experimental test platform is established and the driving strokes of the two-dimensional piezoelectric steadicam platform are 229.24 μm and241.84 μm with coupling errors of 2.75% and 3.02% respectively.The feedforward controller is designed based on the Bouc-Wen model to suppress the hysteresis problem of the two-dimensional piezoelectric stabilized image platform.The hysteresis nonlinear characteristics of the two-dimensional piezoelectric stabilized platform are analyzed and an asymmetric Bouc-Wen model is developed by introducing asymmetric factors for the hysteresis characteristics.Parameter identification of the model is carried out by MATLAB/Simulink.The linear displacement and planar trajectory tracking performance of the two-dimensional piezoelectric steadicam platform were experimentally tested after feedforward control,and the relative error of linear displacement was reduced by more than 60%.To further improve the steadicam accuracy and compensate for the shortcomings of feedforward open-loop control,a classical PID control algorithm is used to construct a closedloop control loop.A first-order low-pass filtering algorithm is applied to avoid the signal noise from causing the closed-loop system to become unstable.Experiments are conducted to test the linear displacement,sinusoidal trajectory,and planar trajectory tracking capability of the 2D piezoelectric stabilized stage.With the closed-loop control,the 2D piezoelectric stabilized stage can meet the displacement compensation of the optical lens with high accuracy and fast response.