Unifying Robot Arm Control

A unified approach to three stages of robot arm control is presented based on the Newton-Euler equations of motion. The stages unified are resolved motion, gross motion, and fine motion. Apart from the conceptual advantage, this unification can require less computation than if the three stages are computed separately. In particular, fewer computations are required for arms with no more than about a dozen joints (a number unlikely to be exceeded for most arms, at least in the near future). Computation times are estimated assuming the computing elements are fabricated from current (very large-scale integrated circuit) (VLSIC) technology. It is also shown how friction can be incorporated into the unified approach. The concept of "pseudo-force" is introduced to relate fine motion to the Newton-Euler equations.