Line-of-sight Stabilization Of Acquisition, Tracking And Pointing System On Moving Bed

Experimental and simulation researches are implemented on basic concepts, key unit technologies of line-of-sight stabilization of acquisition, tracking and pointing (ATP) system on moving bed. System simulation gives the complete system performance estimations. The simulation models are used to analyze the characteristics of the system and the experiments are used to check the simulation results. The conformance of the experimental and simulation results makes it possible to provide valuable system performance estimations.When the ATP system is setup on a moving bed, movement and angular jitter of the bed will cause system line-of-sight high frequency jitter. For the characteristic of low frequency movement of the target and high frequency system line-of-sight jitter, basic theory of compound axes line-of-sight stabilization system with line-of-sight pointing reference unit (LOSPRU) is analyzed.A high accurate transfer function identification method is provided. The transfer function model is built according to the frequency characteristic and working mechanism of the control object. Then the measured frequency characteristic can be converted to high accurate transfer function with curve fit method, rational initial parameters choice and fitting in different frequency range method. With the high accurate transfer function it is possible to design frequency characteristic compensator to eliminate the mechanic resonance frequency characteristic of the control object. The fast steering mirror system closed bandwidth is no longer restricted by the mechanic resonance frequency and the closed bandwidth is expanded effectively. With this method the system margin and system characteristics of ATP gimbals control system can be improved. The identification of transfer function can facilitate the design of a compensator to get rid of manual debugging and provide complex compensator for high performance fast steering mirror and gimbals control system.A stabilization experiment is completed on a one degree-of-freedom rotational bed with fiber optical gyroscope (FOG) feedback. A method is provided to measure the friction parameters of the bed. The maximum friction torque, Coulomb friction torque, viscous friction coefficient and moment of inertia can be gotten by fitting the free reduced rate curve of the gimbals and measuring the motor current when the motor begins to rotate. The simulation model with friction characteristic is built. The experiment and simulation results show that the stabilization error peak is caused by the step friction torque when the disturbance changes its direction. The step friction torque is the main source for the stabilization error. Experiment and simulation show the same result in rejection frequency characteristic and time domain stabilization error. The current loop technique improves the stabilization bed ability to reduce base disturbance direct drive constraint couple and enhances the torque sturdiness. The stabilization error is reduced with current loop technique under same base angular disturbance. Theory of getting inertial angular position from linear accelerometer measurements with double integration algorithm is analyzed. Error analysis on getting inertial angular position with linear accelerometers is improved. Accelerometer noise, double integration algorithm...