Haptic device for physiologically adaptive handle operation

Significant progress has been made in developing serial and parallel robotic systems for haptic devices. However, the integration of robot motion with human operational capabilities, particularly considering physiological constraints of the limbs, remains largely underexplored. To address this gap, this study presents an innovative cooperative kinematics evaluation method that aligns robot motion modes with natural human upper limb movements, incorporating physiological characteristics. Using this framework, we introduce a novel two-degree-of-freedom parallel robot for handle operations with spherical translational motion. This robot offers a significantly enhanced operational range compared to traditional spherical rotation robots. The design utilises a dual five-bar mechanism to achieve both the desired movement and a compact structure. We describe the kinematic modelling, performance evaluation, force control, and prototype implementation of the device. Motion experiments, including platform movement, human handle operation, and haptic impedance control, demonstrate that while wrist physiology limits conventional spherical handle operations, the proposed robot design substantially expands the operational space, highlighting its potential in applications such as minimally invasive surgery and rehabilitation.