Introduction

Abstract

There are many environments in which it is not practical to do things with your own hands directly. For instance, it is not wise to enter a nuclear plant to perform device maintenance. In that case, it would be smarter to position robots inside the plant that can be directed by the maintenance worker outside of the plant. Another example is a keyhole procedure in surgery. In this procedure, instruments are inserted into a patient through tiny holes, to avoid large wounds in relatively simple procedures. The surgeon could use his own hands to guide the tools, but quite often, the surgeon actually uses a joystick to guide a robot to insert the tools, because this enables him to scale his movements to small and precise movements inside the patient. So, both the maintenance worker and the surgeon use teleoperation systems: systems consisting of a master, which is the interface (such as a joystick) that is used by a human (from now on called operator), and a slave, which is the robot that is performing the action in the remote environment (Srinivasan and Basdogan, Comput Graph 21(4):393–404, 1997). Obviously, there are large advantages to teleoperation techniques for the operators: the maintenance worker in the nuclear plant is not exposed to radiation and the surgeon has a far better view of his patient, because his hands are not in the way. However, there is also at least one large disadvantage to this technique: since the master and the slave device are usually not directly connected, the operator cannot directly feel what the slave is doing. When he would be performing the task with his own hands, he could have used sensory information from his hands, also called haptic perception, to feel what the slave is doing. To solve this problem, haptic feedback can be incorporated in the master device, which is the virtual equivalent of natural haptic information.