Abstract：This paper investigates the configuration space description and collision avoidance problem fordual-robot coordination system, the two cooperating robot arms is modelled as a closed chain system dueto constrained relationship, then an algorithm computing the degree of freedom is given by Wittenburgmethod, and the explicit representation of the reachable configuration space is presented, finally, a procedure solving the paths planning problem for two cooperating robots in the presence of obstacles is developed.
 Tarn T J, Bejezy A K, Yun X. Nonlinear feedback control of multiple robot arms: closed chain and Corce feedback formulations. Proc of the NASA Workshop on Telerobotics, JPL, Jan 1987
 Tomas Lozano-Perez. Automatic planning of manipulator transfer movements, Robot Motion. Brady,Hollerbach, etc, The MIT Preas, 1982