Sampling Correction of Steering Gear Control System for Autonomous Underwater Vehicle

The error correction for analog-to-digital(A/D) sampling by analog circuit processing is relatively mature. But it is relatively difficult to be implemented. And the digital correction has not been actually verified. In this paper, aiming at the sampling problem of steering gear control system for an autonomous underwater vehicle(AUV), the reason, proc-ess and result of generating sampling deviation are analyzed by considering the characteristics of the A/D sampling module on a TMS320F2812 chip, and the principles of sampling correction are described. Accordingly, graphic method and formula method are proposed for the error correction. In graphic method, the difference between duty cycle of actual pulse width modulation(PWM) and theoretical sampling value are compared for error correction through a graphical way. In formula method the theoretical formula is compared with actual output to get correction formula. Experimental results show that the steering gear control system achieves a good position tracking performance through internal digital cor-rection, and the control precision fully meets the design requirement of steady-state error.