Double-layer slider-crank mechanism to generate pulling or pushing sensation without an external ground

When a small object in a hand-held device moves periodically and prismatically with asymmetric acceleration (strong in one direction and weak in the other), the holder typically experiences the kinesthetic illusion of being pushed or pulled continuously by the held device. We investigated this perceptual effect for its potential application to a hand-held, non-grounded, haptic device that can convey a sense of a continuous translational force in one direction, which is a yet missing tile in haptics research. A one-degree of freedom haptic device based on two symmetric slider-crank mechanism was constructed to convert the single-speed rotational cyclic movement of a motor into asymmetric translational cyclic movement with asymmetric acceleration and to cancel unwanted side acceleration. We verified our previous results with the haptic device and investigated the effect of the gross weight of the device on force perception.