Connecting haptic interface with a robot

Specific issues of force-reflected telemanipulating systems are addressed in this article. The authors´ approach that might be used in robotic assisted surgery is based on combination of the best and complementary characteristics of a human operator and of a robot. Simultaneously the operator uses his own judgement, manually guides the slave robot, while the master robot (haptic interface) provides both the geometric accuracy through software motion constraint and tactile feedback for the operator. A three degree of freedom (DOF (x, y, z)) force feedback telemanipulating system was built. It is based on the PHANTOM Premium 1.5 haptic interface acting as a master and the ASEA IRb 6 industrial robot acting as a slave robot arm. A new control scheme was introduced, the position-error-based force reflection scheme with variable gain. This method was used for the "tele-drilling" experiment carried out on various hard and soft materials including aluminium, wood, bone and soap. The geometric accuracy and fixation along the z axis of drilling were achieved by a cylindrical motion constraint in software of a master robot arm.