Transmission of tactile roughness through master-slave systems

In this study, a tactile-roughness transmission system applicable to master-slave systems with a communication time delay is developed. The master-side system constructs a local model of target objects placed in the slave-side environment. Tactile feedbacks presented to an operator at the master side are produced by combining the physical properties of target objects in the local model and the kinetic information of the operator. The time delay between the operator´s motion and the tactile feedback is cancelled because the stimuli are synchronized with the exploratory motions. The proposed system is applied to the transmission of tactile-roughness. The tactile stimuli presented to the operator are vibratory stimuli whose amplitude and frequency are controlled. These stimuli are locally synthesized by combining the surface wavelength of target objects and the operator´s hand velocity. Using the developed tactile-roughness transmission system, an experiment for transmitting the perceived roughness of grating scales was conducted. As a result, the roughness perceived by the operators was found to highly correlate with the roughness of the scales in the slave-side environment with a coefficient of 0.83.