Temporally Coupled Dynamical Movement Primitives in Cartesian Space
This addresses orientation control challenges for robotics, but appears incremental as it builds on existing DMP methods with a specific adaptation.
The paper tackled the problem of controlling robot orientation in Cartesian space by using unit quaternions to represent orientations and designing a control system for temporally coupled dynamical movement primitives, with functionality verified experimentally on an industrial robot.
Control of robot orientation in Cartesian space implicates some difficulties, because the rotation group SO(3) is not contractible, and only globally contractible state spaces support continuous and globally asymptotically stable feedback control systems. In this paper, unit quaternions are used to represent orientations, and it is first shown that the unit quaternion set minus one single point is contractible. This is used to design a control system for temporally coupled dynamical movement primitives (DMPs) in Cartesian space. The functionality of the control system is verified experimentally on an industrial robot.