OPTIMAL GEOMETRIC STRUCTURES OF FORCE TORQUE SENSORS

In controlling manipulators interacting with the external environment, an important role is played by the force/torque sensors. In recent years, a number of constructs for such sensors have been proposed, and some criteria for their evaluation have been introduced This article presents a systematic analysis of force sensors at the design stage, which has not been undertaken in the literature. A generalized model of the sensors is developed on the basis of static and kinematic equations, and a block form of the resulting strain compliance matrix of the sensor is obtained. The model developed is then applied to the analysis of two- and three-dimensional sensor schemes corresponding to regular polygons and polyhedrons, respectively. The condition number of the normalized strain compliance matrix of the sensor is used as a performance index. The impossibility of reaching the optimal values of this criterion is stated for the regular polygon form-based sensors. Partial solutions of the optimization problem are found out for the regular polyhedron form-based sensors. The presentation of the material is illustrated by analytical examples.