Evaluation of A Haptic Interface
Three criteria for effective interface: (J.K. Salisbury) a. free space must feel free b. solid object must feel sniff c. virtual constraint must not be easily saturated These descriptions above can be illustrated by five indicators which are mainly considered for designing a general haptic device: 1. DOF (degree of freedom) 2. workspace a comfortable angular workspace was estimated to be of the order of 90 degrees of pitch, and yaw combined with a roll of 120 degrees. 3. resolution average position just-noticable-difference (JND) for wrist and elbow are both 2 degrees. 4. maximum output force 5. back-drivability transparency: how realistic the feeling of touch is when user is touching the virtual object via haptic device. => improving the transparency of haptic interaction is a goal. a haptic device has to transmit force sensation as realistic as possible to user through well-controlled actuators. when detectin