Improvements in the control of robotic motion simulations using the ATB model

Abstract

Modifications were made to the control model for torque generation in the Air Force Articulated Total Body (ATS) simulation computer program. Limb motion stability was improved by introducing integral control in the existing feedback control equation. Motion studies were performed using a Merlin robot model to determine control equation gains for single and multi-joint rotations up to 180 degrees. The robotic motion was made to resemble coordinated angular motion profiles that had previously been determined for similar human arm motion. The control equation gains for the six joints examined were added to the input description as a tabular set of data, which the program could access depending on the joint target angles prescribed by the user. Simultaneous multi-joint rotations were also studied using the same controlling values as were used for single joint rotations. These numbers produced accurate results for all joint rotations, as long as either the shoulder or elbow joints were held at their initial angular positions. The errors produced when the target angles for both the shoulder and elbow were non-zero were less than two degrees of arc.