Inertia compensation of a planar robot for human upper limb interaction

Abstract

This thesis documents the development of software and a control system for the InMotion2 planar robot. Software was developed to provide sensor input processing from the robot encoders and force/torque transducer, and output processing for the robot motors. A controller scheme was developed to compensate for the natural robot configuration-based inertia as well as friction and un-modeled dynamics. The inertia compensator was designed using an inertial admittance model and a nonlinear robust adaptive tracking controller based on sliding mode control. A hybrid control mode was developed in which impedance control was used to enforce a virtual constraint and inertia compensation acted along the constraint. The controller proved to be stable throughout testing and provide the desired inertia. The accuracy of the inertia compensation was within human perception limits for modest inertia references.