抄録
An assembly task-oriented manipulation system (ATOMS) is proposed that monitors the changes in task process and switches task strategy accordingly. The system is divided into five functional blocks: task description, motion planning, motion execution, motion monitoring, and robot control. The assembly process is described as a series of discrete contact states and the task is programmed as sequence of motions connecting the current contact state to the next desired one. During task execution, the motion can be switched in realtime if a contact-state transition is detected. The An experimental manipulation system was developed based on the concept of ATOMS. It has a fourlayer structure, a 6-DOF direct-drive manipulator and a multi-processor, multi-task controller based on a transputer. In the second layer, a motion monitoring and evaluation (MME) module, in which the proposed detection algorithm is installed, and a motion execution management (MEM) module are simultaneously executed. The result for a square peg insertion task, programmed with a few primitive motions, in which different types of contact-state transitions occur and a position (orientation) error is introduced in the task environment, demonstrate that not only is the concept of ATOMS effective, but also that a manipulation system has the ability to execute assembly tasks with high reliability.
