The Design Of Computer-Based Electromagnetic Position And Orientation System

The measuring method of electromagnetic time-division is used in the electromagnetic orientation system which comes from the HMD/HMS applied in the battleplane and detects the orientation of the pilot's head. The algorithm of LOS (line of sight) is a difficulty in this research field, whose key problem is working out position of the LOS precisely.This system measures the position and orientation of the sensor using electromagnetic method. The traditional equipment adopted AC electric current as transmitting signal and Euler angle as calculation parameters. The problem of the equipment is that the calculation results appear distortion when angle is near to 45°. Based on deeply analyzing the method, this paper describes the quaternion which is widely used in locating rigid body. The results show the outcome precision and rate of convergence of the quaternion algorithm with quaternion is better than the traditional one. And this system adopts DC pulse transmitting signal to avoid the eddy current in metal objects nearly.This system chooses the data acquisition card for sending and acquisition tool, builds the data acquisition system. This module transferred the driver to realize the accessing of card using dynamic link library technology. It can improve effectively the transfer speed between the data acquisition card and computer. It adopts Matlab software as data processing tool. The interface programming between VB and Matlab is based on COM groupware. The system can achieve the request of real-time monitoring.