Evaluation of a backlash compensation method using two parallel thrust wires

Advancement of the technology in the modern world facilitate for the development of many human supported machines such as robots. These machines use different kinds of mechanical structures and electrical dive systems with the use of proper controllers to achieve the desired task. However most of these robots need to be miniaturized although it is constrained due to various problems such as the actuator size and the performance. To overcome such problems, several proposals have already made to transmit the motion from one place to the other. Thrust wires are one such method to transmit the motion from the motor to the end effector whenever it is necessary to make the end effector lighter in weight. Many of these thrust wires are low in friction but the mechanical backlash is a matter of concern. Also it greatly affects the bilateral control systems as the master manipulator cannot produce the haptic information related to the dead zone of operation. This paper proposes a method to overcome the backlash of thrust wires using two parallel wires to actuate a common end effector. Experimental results confirm the validity of the proposed method.