Research On Intelligent Control Algorithm For UAV Three-axis Self-stable Pan-tilt

The technology of Unmanned Aerial Vehicle (UAV) low altitude remote sensing is one ofcurrent hot research topics at home and abroad, and self-stable Pan-tilt is an indispensablecomponent. The high precision self-stable Pan-tilt can effectively isolate carrier’s disturbance,and keep the airborne camera visual axis steady. It plays an important role in obtaining highquality low altitude remote sensing image. Pan-tilt technology is also widely used in targetdetection system, missile and the kinetic energy weapons precision guiding systems, autonomouslanding control system of unmanned aerial vehicle or shipboard aircraft, etc. The Developmentof high-precision Pan-tilt technology is great significance to our economic and national defenseconstruction. About UAV three axis self-stable Pan-tilt, this paper carried out the followingresearch:(1) For small low-altitude UAV remote sensing system, the mathematical model of threeaxis self-stable Pan-tilt is established. Putting three-axis self-stable Pan-tilt as the research object,analyzed its structure in detail, built up the coordinate system of ground, the carrier, the sight andeach frame rotation system, and established its mathematical model according to the Newtonianmechanics principle, analyzed its various disturbance factors. These established a foundation forsubsequent precise control. And the classical PID was used to simulate system.(2) As classical PID controller’s structure is simple, cannot meet the demands of theprecision of the complex control system, the PSO fuzzy PID control system is proposed. It hasstrong adaptability, fast response and global optimization ability. The simulation results showthat the system has a higher steady precision than classic PID, and the system has no overshootand adjustment time is short. It can adjust the parameters according to the real-time situation. Ithas a good effect to the three axis self-stable Pan-tilt.(3) In view of the complex interference factors of three axis self-stable Pan-tilt, the fuzzyPID control algorithm based on self-adaptive Kalman filter is proposed. The self-adaptiveKalman filter technology is introduced into the system, taking the maximum a posteriori (MAP)noise estimator Sage-Husa to estimate the mean and variance of the interference noise. Thesimulation experiments show that the new algorithm can effectively restrain control noise andmeasurement noise of system. It improves the system’s performance, effectively reduces thesystem’s error.