The Adaptive Control Of The Magnetic North-Seeking System

In the life and practice of people, the information of geographical orientation is essential. So it is instructive to do research on the orientational and directional instrument. People have always been making great efforts to explore the technology of orientation and direction for long time. The occurrence and application of the inertia and computer control make it possible to devise and develop the independently and precisely orientational instrument.As a kind of precisely inertial instrument, the orientational accuracy of the north-seeking system is decided by the accuracy of the gyroscope it used to a large extent. What we studied in this paper is a typical magnetic north-seeking system, whose gimbal axis is suspended by making use of adaptive control and magnetic floating technology. The purpose of the research is to make the north-seeking system much more accurate and raise its speed at the same time.This paper analyzes the mechanical and electronic structure of the magnetic north-seeking system, introduces its working principle. Through these analyses, the transfer function of the single degree of freedom electromagnetic model is established by linearization at the equilibrium point, and the state equation of the magnetic north-seeking system in low rotating speed is derived consequently.Due to the opening loop instability and very strong nonlinearity of magnetic floating systems, researches on controlling method become very important. The quality of the controller affects the dynamic performance of the system directly. Adaptive control has many advantages such as, easy to calculate, robust, suitable to the unminimum-phasic system, which make it very fit for the control of the magnetic system. Therefore this dissertation applies adaptive control technology to realize the digital control of magnetic north-seeking systems. The simulation results show that the pole assignment adaptive PID control method is superior to the classic PID control. This adaptive controller achieved the desire of system design, so the task of system design is accomplished.