[Remembrance characteristic of softness haptic perception in human fingertips]

Many applications in virtual reality and telerobot call for the implementation of displaying the human softness haptics on the object being touched. Although there are lots of literatures on discrimination threshold for displacement, force magnitude, shape and viscosity, there is still a lack of research on remembrance of softness haptic perception in human fingertips. Such research is needed in designing haptic rendering and display system. In this paper, a novel softness haptic display device based on deformable length of elastic element control was adopted as a test device to study the human fingertip's ability of remembrance of softness haptic perception. According to the recall experiment and recognition experiment, the softness haptic memory span and reaction time were discussed. From the experimental results, some important conclusions have been obtained: (1) human softness haptic memory span is 3 to 4 items, which is smaller than visual memory span and auditory memory span; (2) it is more difficult for people to remember hard objects than soft objects.