The Method For Restraint Of Destabilization Of Airborne Photoelectric Stabilized Platform

Aerial photoelectrical stabilized platform is widely used in the zone of enemyinvestigation, target location, attack collation and effect evaluation. Optic axisstability is an important metric for charactering the stable plan. With higher optic axisstability, the accuracy and image quality of the plan will consequently raise.Nevertheless, limited by the rigid body motion of the plane, engine vibration andturbulence of the airflow, the output moment of the electric-motor cannot be totallytransferred to the frame and this leads to the deviation from the perfect location ofpointing model.so we place significance on the robust of the plan system.In this article, after processing the specification of the turbulence in theory, wedegrade the restrain strategy into two individual parts: the active restrain and thepassive one and this paper will be organized as follows.To begin with, according to the mechanical structure of the stable plan, wedevelop a method from the motion and dynamic equations to restrain the couplingamong the frames. Thus, the optimize design of the plan provides a requirement forthe control system of the plan.In the second place, we design the current loop separately for every frame, inorder to provide a smooth moment output.The analytical determination that how thesensitivity for the various kinds of turbulence moment influences the plan pointingaccuracy will be received.Based on the current loop, we investigate the control currentwhich specifies both the turbulence moment and model error. Modeling in this way, for one thing, we can understand the error model more easily.For another, theconstruction of active control strategy will benefits from it.In speed stability loop, the traditional square lag-lead compensation method andsquare PI controller can provide adequate passive restraint and improve theperformance of the controller in the low part of the frequency domain. The two-stageADRC whose estimated value of disturbance is oriented by target value, combines theactive and passive strategy, is involved for contribution to the iso-vibration of thesystem and optic axis stability.Lastly, an experiment was performed to test the disturbance rejectionperformance of the ADRC based on current loop when the speed disturbance is from0.1Hz to2.5Hz as compared with the traditional square lag-lead compensation method.Experiment results show that ADRC can reduce the disturbance error8.52dB at least.And the isolation degree of disturbance is improved obviously when the perturbationfrequency is more than0.5Hz. The best isolation degree of disturbance is increased13.06dB. And the ADRC have strong robustness, allowing the range of systemparameters to change in15%. In addition, the disturbance rejection performance ofthe ADRC whose estimated value of disturbance is oriented is improved more thanone time in the temperature test and vibration experiment.In conclusion, the ADRCwhose estimated value of disturbance is oriented satisfies the performancerequirements of aerial photoelectrical stabilized platform and have higher practicalvalue.