Error Correction of 6-DOF Head-tracking System

6-DOF(Degree of Freedom) head-tracking system based on CCD image processing is developed,and the measure errors of 6-DOFs are analyzed,which is caused by beacon accuracy and interdependence among 6-DOFs.In order to reduce the initial error caused by beacon accuracy,initial error correction program that the degrees return to zero at initial state is proposed.Then the initial errors are corrected without high-precision beacon.In addition,independent measurement program that the freedoms are extracted separately is proposed to avoid error transfer.Experimental results show that 6-DOF errors are reduced greatly after error correction and improved algorithm.In the azimuth angle range of-30°~30°,the standard deviation of azimuth angle α is 0.94°,the standard deviation of roll angle β and pitch angle γ in 0° position are 0.30° and 0.02° respectively,the standard deviation of position xo and yo in 0 cm position are 0.94 cm and 0.01 cm respectively,and the standard deviation of position zo in 112.31 cm position is 0.28 cm.