A new admittance-type haptic interface for bimanual manipulations

The concept of a new mobile haptic interface for bimanual manipulations in 6 DOFs is presented. The design of this mobile haptic interface is based on a modular system consisting of two components: two admittance-type haptic interfaces and a mobile platform. While the haptic interfaces cover only parts of the human arm workspace, the mobile platform extends these to arbitrarily wide remote environments. This paper mainly addresses the design and control concepts of the haptic interfaces, which are planned to be mounted on the mobile platform. The interfaces dispose of a large workspace and a high force/torque capability. A special design and control concept of the haptic interfaces makes it possible to decouple translational from rotational movements. This decoupling helps to significantly simplify the control algorithms that handle the interaction between the single components. Evaluation results concerning the Cartesian position tracking performance and the impedance display fidelity are provided. In addition, the following performance measures are analyzed: dextrous workspace, output capability, and backdrivability. In order to reduce the measurement effort, some of these measures are determined by model-based, others by measurement-based performance evaluation.