  Product disassembly is a labor-intensive process and is far from being
automated. Typically, disassembly is not robust enough to handle product
varieties from different shapes, models, and physical uncertainties due to
component imperfections, damage throughout component usage, or insufficient
product information. To overcome these difficulties and to automate the
disassembly procedure through human-robot collaboration without excessive
computational cost, this paper proposes a real-time receding horizon sequence
planner that distributes tasks between robot and human operator while taking
real-time human motion into consideration. The sequence planner aims to address
several issues in the disassembly line, such as varying orientations, safety
constraints of human operators, uncertainty of human operation, and the
computational cost of large number of disassembly tasks. The proposed
disassembly sequence planner identifies both the positions and orientations of
the to-be-disassembled items, as well as the locations of human operator, and
obtains an optimal disassembly sequence that follows disassembly rules and
safety constraints for human operation. Experimental tests have been conducted
to validate the proposed planner: the robot can locate and disassemble the
components following the optimal sequence, and consider explicitly human
operator's real-time motion, and collaborate with the human operator without
violating safety constraints.
