Understanding the geometric areas of contact with an object for different user motions is generating both tactile feedback requirements and also a physical-based model that can determine if an object has been picked up. The latter will improve on current models that just measure geometrical proximity for this purpose. It is gravity compensated, so that the operator does not bear the weight of the system. Each joint on the exoskeleton is actuated by means of DC servomotors located on the structure. The motion of each joint is obtained through a tension, tendon-based transmission system that includes complex cable routings for the elbow and forearm joints.
Torque sensors measure the differential tension of the cables actuating each joint.
I tested the system by moving around and against a simply modeled geometric object containing planar sides in virtual space. The results were impressive as the system was responsive and the force feedback strong and accurate. The claimed innate system delay is 2 msec. Bergamasco has studied the operation of the tendons of the human forearm and hand. He notes that the actual interaction is more complex than the current modeling by one cable to push and one to pull.