Multi-actuator Cooperative Control For Scanning Imaging Motion Compensation In Aerial Remote Sensing

As an important aviation remote sensing equipment,the aerial camera is widely used in military and civil.To accomplish a larger area of remote sensing task in a limited time,scanning imaging technology is used in aerial cameras.Scanning imaging includes push scanning and swing scanning,among which swing scanning has been widely concerned because of its advantages of a large range.At present,to improve the dynamic performance by reducing the inertia,mirror swing scanning is often used instead of the whole machine swing scanning.However,the image of the object will move relative to the image sensor during the scanning,which leads to image rotation and image motion.Image rotation and image motion will lead to image blur and field of view reduction.To realize the motion compensation in the scanning imaging,the cooperative control of multiple actuators is added to the systems.Because of the control structure,control method,and signal processing involved in compensation control,the following research work is carried out in this paper:1.Based on the system structure and reflection theorem,the mathematical models of image motion and image rotation in scanning imaging systems are analyzed.The functional relationships between various scanning trajectories and compensation trajectories are established.The feasibility of image rotation and image motion compensation by multi-actuator cooperation is clarified.Considering the constraints of travel and field of view,two modes of compensation and reset are designed,and the compensation strategy of periodic switching is proposed.Besides,the trajectory planning and command design are completed based on the image rotation and image motion model,which lays the foundation for the follow-up control method research.2.Considering the requirements of multi actuator cooperation in scanning imaging motion compensation,a multi actuator cooperative control structure with mode switching is proposed.Image rotation and image motion are compensated in this structure at the same time.Multi actuator cooperation is realized by the cooperative controller,which reduces the influence of subsystem dynamic model parameter difference on imaging quality.For the problem of too many parameters in multi actuator system,the model of controlled object is simplified,which reduces the difficulty of controller design.The influence of mode switching on the stability of the system is discussed,and the stability criterion of the system is given in the frequency domain.The experimental results show that compared with the non-cooperative control structure,the tracking root mean square error and cooperative root mean square error of the multi actuator cooperative control structure are reduced by 11.32% and 16.96%.3.To further improve the control performance of multiple actuators,a new adaptive sliding mode control method is proposed.By designing the adaptive reaching rate coefficient,the response speed is improved and the chattering is suppressed.The adaptive sliding mode is successfully applied to the design of the tracking controller and cooperative controller of the multi actuator control structure,and the stability of the system is proved by the Lyapunov method.The experimental results show that compared with the PD controller,the root mean square error of tracking and cooperation are reduced by 72.32% and 72.74%.4.To reduce the influence of noise amplification on the controller,a fuzzy selftuning tracking differentiator is proposed.The filter characteristics of the differentiator are analyzed,and the off-line optimal parameter design is realized by particle swarm optimization.A fuzzy adaptive tracking differentiator is proposed for online parameter adjustment.The fuzzy inference rules are designed flexibly according to the signal-to-noise ratio,and the differentiator parameters are obtained by fuzzy inference from the spectrum analysis results.The simulation and experimental results show that the adaptive self-tuning differentiator has better filtering performance for low-frequency signals and better tracking performance for high-frequency signals.In summary,the control of scanning imaging motion compensation for aerial remote sensing is discussed in this paper.The multi actuator control structure,adaptive sliding mode control method,and adaptive tracking differentiator are deeply studied,which lays a foundation for the further development of aerial remote sensing technology.