On the Ability of Humans to Haptically Identify and Discriminate Real and Simulated Objects

The ability of human subjects to identify and discriminate between different-sized real objects was compared with their ability to identify and discriminate between differentsized simulated objects generated by a haptic interface. This comparison was additionally performed for cases of limited force and limited stiffness output from the haptic device, which in effect decrease the fidelity of the haptic simulation. Results indicate that performance of size-identification tasks with haptic-interface hardware capable of a minimum of 3 N of maximum force output can approach performance in real environments, but falls short when virtual surface stiffness is limited. For size-discrimination tasks, performance in simulated environments was consistently lower than performance in a comparable real environment. Interestingly, significant variations in the fidelity of the haptic simulation do not appear to significantly alter the ability of a subject to identify or discriminate between the types of simulated objects described herein.