Haptic discrimination of material properties by a robotic hand

One of the key aspects of understanding human intelligence is to investigate how humans interact with their environment. Performing articulated movement and manipulation tasks in a constantly changing environment, have proven more difficult than expected. The difficulties of robot manipulation are in part due to the unbalanced relation between vision and haptic sensing. Most robots are equipped with high resolution cameras, which images are processed by well established computer vision algorithms such as color segmentation, motion detection, edge detection, etc. However, the majority of robots have very limited haptic capabilities. This paper presents our attempt to overcome this difficulties by: (a) using a tendon driven robotic hand with rich dynamical movements and (b) covering the hand with a set of haptic sensors on the palm and the fingertips, the sensors are based on a simplified version of an artificial skin with strain gauges and PVDF (polyvinylidene fluoride) films. The results show that if the robotic hand actively explores different objects using the exploratory procedures: tapping and squeezing, material properties such as hardness and texture can be used to discriminate haptically between different objects.