FORCE CONTROL EXPERIMENTS WITH A 2-ARM ROBOT

The goal of this paper is to present solutions for manipulating objects with two robotic arms, when force control is necessary. The applications we are interested in are the transport and assembly of rigid objects, the deformation, transport and assembly of flexible objects, and the assembly in space of two objects, with each being held by one arm. We present a theoretical solution for modeling the tasks and the practical solutions we have implemented for controlling two six-axis arms in a real experiment. In each case, the task is described by a position vector and a force vector, which are used jointly in a hybrid position/force control scheme. The position vector consists of the absolute position/orientation of a frame attached to the manipulated object(s), and of the relative position/orientation of the end effectors. The force vector includes external and internal forces and moments acting on the object(s). This solution allows us to use the same task description for various complex applications: this feature is verv interesting for real experiments, since it reduces the programming burden. We have experienced this advantage when implementing our method on a real experimental setup, which is described in the paper and with which we have carried out several experiments.