SIMULATION ANALYSIS ON FACTORS AFFECTING THE ACCURACY OF AN THREE-AXIS BNERTIAL STABILIZED PLATFORM FOR AIRBORNE REMOTE SENSING SYSTEMS

摘要

Inertial stabilized platforms are key components of airborne remote sensing systems, which can support and stabilize image payloads, isolate disturbances of moving vehicles, provide stabilized level position norm to payloads, and markedly improve the quality of remote sensing images. The stabilized accuracy directly affects the definition and resolution of remote sensing images. So increasing platform accuracy is very significant in the design and development of inertial stabilized platforms, and the factors affecting platform accuracy must be discussed and researched. Simulation analysis on the factors was done based on inertial stabilized platform system model in this paper. First of all, the system model of an inertial stabilized platform was simply introduced, which is quite dissimilar to that of an inertial navigation platform. Secondly, to analyze the factors which affect stabilized platform accuracy, its simulation system was set up according to the system model. In order to expediently discuss and analyze the factors, a classical control scheme based on PID algorithm was designed. Besides, the control system adopted an inner rate or stabilization loop inside an outer position or track loop. Finally, simulation experiment was performed. The affection factors which were torque disturbances (imbalance, friction and kinematic coupling), erroneous torque equivalent inputs (gyro drift and gyro misalignment) were researched, and all values were estimated considering the actual conditions. So the simulation results are reliable, which can mostly reflect the performance and error characteristics of actual platform, providing theoretical guidance and technical support for platform development, and reference for research on other type platforms as well.