It is shown that by integrating joint torque sensing and tactile sensor spatial and force information it is possible to increase the sensitivity in measuring the applied forces and contact locations. Using tactile sensors on a whole-arm manipulator (WAM) overcomes a number limitations in the joint torque method due to insufficient or low-accuracy measurements. In addition, a methodology is presented for determining design parameters for a tactile sensor given the requirements of a particular task. Specifically, the authors consider the design of a tactile sensor covering for the four-degree-of-freedom WAM arm installed at the MIT Artificial Intelligence Laboratory.>

A light-stripe vision system which quickly and accurately locates polyhedral part features is presented. An image of three line segments generated by the intersection of a plane of light and a polyhedral feature is used to localize the feature. Sufficient conditions for six degree-of-freedom positional constraint are discussed and the solution for determining the rigid transformation of a general polyhedral feature is presented. The accuracy of a prototype sensing system in locating a right corner feature is 0.1 degrees (1.5 milliradians) per standard deviation in rotation and 0.002 inches (0.055 mm) per standard deviation in translation. The time required for the measurements is 2.5 to 3 seconds. Much shorter times are also realizable.

The accuracy with which objects that generate images of line segments may be located in the presence of quantization noise is investigated. Expressions for the standard deviation of errors in orientation and translation are derived. The accuracy of these expressions is substantiated by a number of Monte Carlo simulations and experimental tests.