A Novel 6-DOF Force-Sensed Human-Robot Interface for an Intuitive Bilateral Teleoperation

The teleoperation of a 6 degrees-of-freedom (DOF) manipulator is one of the basic methods to extend people’s capabilities in the wide variety of applications. The master interface based on the force/torque (FT) sensor could provide the full-dimension intuitive bilateral teleoperation of a 6-DOF robot since it has the ability to trigger 6-DOF command input. However, due to the force coupling, noise disturbance and unlimited input values of the FT sensor, this forces-sensed interface could not be widely used in practice. In this paper, we present an intuitive teleoperation method based on the force-sensed sensor from mechanical design and input force signal process to overcome these challenges. In this method, the input signals from the force-sensed joystick were filtered and then processed to the force commands by force limit algorithm, with the merits of anti-interference, output limitation, and online velocity adjustment. Furthermore, based on the admittance control and position controller, the manipulator could be teleoperated by the force commands. Three experiments were conducted on our self-designed robotic system. The result of the first experiment shows that the interfered force from the force coupling could be effectively suppressed with the limitation of the input force through force limit algorithm. Then, a parameter was introduced in the other two experiments to adjust the velocity online practically with force limit algorithm. The proposed method could give a practical solution to the bilateral teleoperation based on the FT sensor.