Hybrid Control of a Flexible Manipulator Reducing Interferences between Position and Force responses.

A hybrid control method for a flexible manipulator based on an angular velocity control is presented, which is applicable to curved constraint surfaces. The error of contact force is converted into a velocity vector according to the force/velocity conversion law which consideres both force respose characteristics and variational angular velocity with respect to normal direction of the surface. The velocity vector which is tangent to the constraint surface is calculated using the velocity control law. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vectors. A vibration control law is proposed to reduce overshoot of end point velocity response. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and vibration control term. Motion and force controls without calculating inverse dynamics is performed using DC motors whose desired values are equal to the above desired angular velocity vectors. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.