HAPTIC DEVICE

Apparatus is provided to extend the number of active degrees of freedom of haptic interface to provide the user with the feel of a tool which is cantilevered over obstacles or which experiences frictional drag along its shaft. This is accomplished by providing two additional active degrees of freedom while not limiting the rotation or translation of the handle that the user is grasping. The apparatus constrains, through a 4 degree of freedom gimbal, the shaft of the tool handle, whose tip is controlled by another 3 spatial degree of freedom haptic device. The shaft of the tool slides and rotates in a sleeve bearing or collar which is mounted in a 2 degree of freedom gimbal. The gimbal is rigidly connected to a 2 degree of freedom parallel planar manipulator, with both degrees of freedom of the planar manipulator being powered by actuators used to generate the requisite haptic forces. The use of this device provides users with a 5 degree of freedom device, through which they can feel forces and moments, instead of only point forces which are generated by 3 degree of freedom devices. This is useful when performing simulations where a portion of the tool removed from the tip may contact an obstruction instead of just the tip.