Force control of a single-link flexible robot based on a collision detection mechanism

The paper studies the use of flexible robots in tasks that require a contact with the environment. Here a flexible robot has the advantage that the energy of the collision will be absorbed by the robot structure instead of by the environment. First a tip position control method of a single-link flexible robot for collision-free trajectories is presented. This method offers a behaviour of the flexible robot similar to that of a rigid robot under the same working conditions. We also make here a comparison among different force control methods, stating some conditions to their use. Some experimental results are shown that validate the study. The feasibility of the proposed force control is based on the good results obtained with the collision detection mechanism. This mechanism is made possible by the reliability of the position control method and the detailed analysis made of the reference signal. This work is presented as a first approach that can be generalised to the control of more complex arms.