Control System Design Based On DSP For Platform Stabilization Loop

The inertial navigation system (INS) has a close relationship with the development of navigation, aviation and spaceflight. And the precision of INS is determined by the platform stabilization loop to a certain extent. The conventional platform stabilization loop is constructed by analogue electronic system, which makes the system big, costly and frequently in failure, so digital control is adopted as a new direction. Under this background platform stabilization loop based on DSP is researched in this paper.The platform stabilization loop is theoretically analyzed and compensated. The experimentation result of design and emulation argues that the conventional single-loop PID control is feasible in control precision and response speed, but on the other hand this control method makes the platform system lack of desirable disturbance rejection. But then the problem is solved by double-loop control method which introduces speed feedback into the system. Refer to the above and the analysis and comparison of several fuzzy control methods, the method of fuzzy-linear dual-mode control is proposed. In this instance the structures of speed-loop and position-loop linear controller are identical with those of the linear double-loop system, and the position-loop fuzzy controller is non-quantificational and its factor is self-tuning. In addition the transition of the two controllers of the position-loop is smoothed by using the output intensity coefficients. With this method the platform system has good effect in response speed, precision and disturbance rejection.The software and hardware of digital platform stabilization loopis designed. Hardware interface and theory of digital controller and velocity output are emphasized in hardware design section; PWM wave producing module closely related chip structure is emphasized in software design section. Because DSPs have the advantage in efficiency, speed and precision, TMS320F240, a product of Texas Instruments Inc., which has 12 PWM output channels, is chosen as the core chip of the digital control system. It makes the motor control more convenient. AD2S81A, R/D converter of Analog Devices Inc., is chosen to substitute for the velocity measuring dynamo to gain the speed feedback signal. It reduces the system dimension and improves the system reliability.