Airborne Ccd Image Racemic Control Technology

With the development of the technology of Airborne Opto-Electronic Platform (abbreviated to AOEP below), the performance of stabilization and track of AOEP has been well improved. But the movement of the AOEP's axes add additional rotation to the image, and brings trouble to the airman's observation. So the image rotation compensation control technology(called CCD image despun control technology here) becomes a necessary research aspact. The mechanism of the airborne camera image rotation and the necessary of the image rotation compensation is illustrated and the despun angle is calculated. Through analyzing three despun control schemes and the practical requirement, the physical despun scheme is selected for the airborne CCD camera image. According to the system performance requirement and through surveying and analyzing the friction moment and the lead tortile moment, confirm that conquering the friction moment and lead tortile moment is the most important problem to improve despun performance. Aiming at that, the scheme that improve open loop gain or no_error degree based on ensuring the system stability and possible responding speed by using classic frequency domain theory is put forward. Concretely, second lag-leading emendation is applied in the velocity loop, nonlinear subsection fuzzy control and lag-leading emendation is combined in the position loop and velocity feed_forward control according to the input angle is also used in the system. With all this, definite despun precision is achieved. Analysis is made according to the performance instability and inadequate despun precision of the classic control system, the reason is given that the friction moment and lead tortile moment of the system is too strong for the classic control system to deal with , and that the control system is not robust enough for the uncertainty of the system mathematics model caused by the machine temperature transformation etc. To resolve that problem, improved IMC (Internal Model Control)is recommended in the thesis. The emulational result shows that the Improved IMC can settle that problem very effectively and simply, and it's very practicable for the engineering application.