A man-machine interface device is provided which employs rigid links interconnected by measured revolute joints to provide the position of a hand relative to a reference location, such as a desk, keyboard or chair. By proper selection of kinematic structure, and by placing one of the joints near the elbow and extending one of the links along the line of the forearm, translation of the joint-link structure is minimized, hence the undesirable perception of friction and inertia are also minimized. When Hall-Effect sensors are used as the revolute joint goniometers, the permanent magnets of neighboring joints are placed in the same link so the effects of magnetic field interference can be calibrated out. A hand-sensing joint-link device as described herein can produce data which is more noise free, at a higher sample rate, with less latency and more robust that competing electromagnetic, optical and ultrasonic sensing technologies, without adding much encumbrance. The output from the hand-sensing device may be used to produce a graphical 'virtual hand' on a computer monitor which mimics the movement of the measured physical hand. The hand-sensing joint-link device may also be used with a finger-sensing joint-link device to provide data on the movements of the fingers and hand. When a right and left finger- and hand-sensing joint-link devices are used, the wearer can use both hands to manipulate virtual objects on a computer monitor.
Forearm-supported exoskeleton hand-tracking device