Force Sensorless Haptic Display Using External Force Estimation Observer

Abstract

Virtual reality technologies have made remarkable progress in recent years. In particular, head-mounted displays are widely used in the entertainment field because they can be realized as a passive device without human interaction. However, virtual reality also needs a haptic display device to present force to the user, but it is difficult to realize this type of device because the user must interact with it. Position and force sensors are necessary to reproduce the force accurately. These sensors mean that the haptic display becomes large and expensive. If the number of sensors could be reduced, then the haptic display can become small and inexpensive. Haptic displays could be made cheaply if they could be realized without using expensive force sensors. Here, we proposed a control law for realization of sensorless haptic displays using a model-following control. An external force estimation observer was applied to control law and realize a sensorless haptic display. Our experimental results confirm the proposed method. Therefore, haptic displays can be realized without using a force sensor.