Contact Force Perception With an Ungrounded Haptic Interface

Abstract

Two haptic interfaces, each able to provide either grounded or ungrounded haptic feedback, were constructed. Tests were conducted to compare a subject’s ability to perform boundary detection and object size discrimination tasks with grounded or ungrounded haptic feedback, with or without vision. Not surprisingly, grounded feedback is better than ungrounded feedback in displaying forces that stem from grounded sources. However, ungrounded haptic feedback can give comparable results in boundary detection tests. Subjects also reported that the application of forces to the fingertips by a moving paddle, as employed in the ungrounded tests and in some of the grounded tests, enhanced the realism of the virtual boundary contacts. Additional results concerning the synchronization of different feedback mechanisms and the use of a brake for grounded feedback are discussed in terms of their implications for the design of haptic interfaces.

A Lightweight Exoskeleton Force Feedback Glove

“…Based on their working principle and working space, force feedback devices can be classified into grounded and ungrounded devices [11]. Grounded force feedback devices are fixed in place and apply force from the ground (or from a desk) [12]; many products of this type have been put forward, and various end effectors such as pens [13,14], scissors [15,16], and soft balls have been used depending on the purpose of the system. However, the restricted workspace makes it difficult for the user to move freely, thus leading to a lack of flexibility.…”