Method of Object Pose Measurement Based on Single PSD

A pose measurement method based on single position sensitive detector was proposed in order to overcome the limitation of image sensor response and precision and the defect of corresponding image processing algorithm. First, a coordinate system was established while the origin was based on detector photosensitive surface center and space attitude angle was defined in this coordinate system. Then eight infrared LED light sources of plane object glowed in circle were defined as detecting target and they were imaged on the active area of the positive sensitive detector via optic system. After the electricity digital signal had been processed by the program, using two-dimensional image coordinate of feature points and specific relative position relation of light sources, the position and attitude information of object in sensor coordinate system would be gained finally. Before the measurement experiment, the stability of the system was verified. Experimental results show that measurement distance of this method is 10 m in the depth direction within the detectable field angle of 16.3 degrees while the maximum absolute error is 36.2 mm. The maximum position measurement mean absolute deviation in other direction is 7. 1 mm and angle measurement error is higher than 2 degrees. This method is simple while real-time frequency of measurement could achieve 100 Hz and it could meet the real-time requirements in pose measurements commendably.