Performance optimization of a multi-DOF bilateral robot force amplification using complementary stability

This paper presents a novel approach to evaluate the optimal controller for a multi-dof manipulator in a bilateral force amplification context. The main issue with multi-dof manipulators is that their dynamics are configuration dependent. The varying dynamics of the robot is thus taken into account during the optimization process, thereby resulting in a stable controller with exceptionally high performance. Moreover, the coupled stability of the manipulator is assessed with an extended version of the concept of complementary stability which allows to overcome the passivity conditions. Although the optimization proposed here is based on three performance indices specific to bilateral amplification, it can be easily adapted to any type of bilateral interaction. The resulting performance and stability of the optimal controller are demonstrated on a seven-dof serial manipulator with impact tests on different contact surfaces.