Surface-tracking of a 5-DOF manipulator equipped with tactile sensors

Tracking a surface via the end-effector of a manipulator is a tough issue, one not only should implement the position and force control, but also monitor and sense the actual contacting state between the end-effector and the object´s surface. In this paper, we present an approach integrating the tactile sensing with force-torque information as the feedback to control the manipulator tracking a surface. Hybrid impedance control method is applied to follow both the position and force trajectories. At the same time, the posture of the end-effector is expected to keep horizontal. With the feedback of tactile sensing data such as contact state, contact area and so on, several strategies of tactile sensing feedback are proposed to be included into the control algorithm. Simulations and two groups of real experiments are made using a 5-DOF manipulator equipped with force/torque and tactile sensors to contact with hard and soft board respectively, and the results are compared and analyzed. The effectiveness of the proposed strategies is validated.