Assembly phase estimation in the square peg assembly process

Almost industrial robot arms have been used in the simple repetitive process such as handling, transferring and assembling the simple workpiece with large tolerance. Nowadays, industrial robots are necessary to apply to the high precise machining process and the high precise assembly process according to the change of automatic manufacturing system. For the high precise assembly process using robot system, assembly strategy and assembly phase estimation are very important in addition to the performance of the robot arm mechanism and robot control algorithm. Vision system and torque sensor are generally used to estimate the contact phase. In the paper, several contact phases in the square peg in hole process are proposed and analyzed using FT sensor. The assembly experiment is carried out using this contact phase estimation and robot shows the successful square peg-in-hoe assembly.