Vision based haptic multisensor for manipulation of soft, fragile objects

We present a vision based multisensor that is designed for robot interaction with small, soft, and possibly fragile objects. The sensor consists of a rubber membrane, a rectangular frame on which the membrane is mounted and a CCD camera. The entire system is airtight. Based on the observed deformations of the membrane, we determine the contact area, the integral force acting on the membrane, the 3D force distribution over the membrane, and derive properties of the target object by monitoring the evolution of its deformation. We can distinguish between different types of materials, i.e., solid, soft, amorphous, and determine the speed and nature of their deformation. The sensitivity of the sensor can be adjusted by changing the volume of air within the rectangular frame. We achieved a small noise to signal ratio, which allows us to observe small integral forces in the range of 0.5N to 2.5N, with an average error of 0.04 N.