Study On Stabilization And Track Control Techniques Of Airborne Opto-Electronic Platform

Airborne Opto-Electronic Platform (abbreviated to AOEP below) has developed rapidly in recent years; it has been used widely in the military area and civil area such as public security, fire protection, surveillance and control of environment etc. It is a complex system composed of optics, mechanism, and electricity. Stabilization and track are the two main functions that its servo system must try to accomplish. Based on experiments, control technique for stabilization and track of AOEP has been studied in depth in this paper.At first, configuration method of stabilization of LOS and survey of development of AOEP in the world are summarized in this paper, and then principal of how movement of airplane can be isolated by a two-axis-platform is analyzed theoretically. Requirements of stabilization of LOS to servo system are put forward. It provides the basis of theory for designing servo system. According to the actual situation and performance requirements, we found that how to bate the influence of friction in the system is the principal difficulty for us to improve stabilization accuracy. To solve this problem, a method using double speed loops, combined with technique of nonlinear acceleration compensation is brought forward and applied in the servo system. Very high stabilization accuracy is acquired. For further study to improve performance, an adaptive control algorithm based on Neural Network is tried in stabilization control. A new method of selecting the initial weights of Neural Network is put forward, which is that the coefficients of discrete equivalent of continuous transfer function in traditional control are used as the initial weights of Neural Network. Adaptive Neural Network control is combined with traditional control by using different method in different segment. It is proved to be a good method and experimental results are given in this paper. Aiming at the difficulty that there are pure long time delays of tracking error of TV tracker and Infrared tracker, theoretic analysis of influence of delays to the tracking performance is given based on the Type â…¡ system. The relationship between time delays and cutoff frequency of open loop and the result that the longer the delays, the lower the cutoff frequency of open loop and the tracking precision are educed. To overcome the bad effect of long delays, a prediction and compensation method based on an adaptive filter, which uses LMS algorithm and structure of transversal filter is provided. Performance of convergence of the algorithm is analyzed. Simulation and experiment results illustrate that this prediction and compensation technique can fulfill the demand of engineering.