Tactile sensing of point contact

Contact location and force are among the most useful parameters for grasping and dextrous manipulation. This paper presents the theoretical results of extracting these parameters from a tactile sensor, which is an array of pressure (stress) transducers under an elastic layer. Using the model of a 3-D frictional point force acting on an elastic half-space, moment analysis is employed to interpret a tactile image. Analytical relationship between the first three moments of the tactile image and contact location and force (magnitude and direction) is established for the cases of a single-layer and two-layer one-dimensional tactile sensor and a single layer multi-dimensional tactile sensor. It is shown that the first three moments of a tactile image are sufficient to recover information about point contact. The corresponding inverse models have simple closed form for efficient computation