Dynamics and optimization of grasping pose of rigid-flexible hybrid hand grasp object

To ensure the stability and safety performance of rigid-flexible hybrid fingertip grasping objects, it is essential to elucidate the coupling relationships among various key forces and to establish a dynamic model. Furthermore, the impact of fingertip contact forces on the stability and safety of the grasp must be taken into account to achieve optimal parameter configurations. In this paper, a new model of a rigid-flexible hybrid hand fingertip grasping an object is established, the hybrid hand consists of three rigid-flexible hybrid fingers. The kinematics and dynamics of the model are solved, and the grasping pose is optimized based on the established stable and safe grasping performance index, which provides a theoretical basis for the safe and stable grasping of rigid-flexible hybrid hand. First, the kinematics, statics, and dynamics models of the hybrid hand are established, and the relationship between the external force/torque on the object, finger actuation torque, spring torque, and contact force are solved. Second, the simulation model of the hybrid hand is constructed, and theoretical solutions are verified by the constructed simulation model. Third, the connection between each component force at the contact point on the stability and safety of grasping is revealed, establishing the corresponding grasping index, which can be used to solve the optimal pose of grasping in the kinematic space of the hybrid hand. Under this optimal pose, the hybrid hand grasps the object in a way that is both stable and safe for grasping and resistant to interference. The paper provides a theoretical basis for the rigid-flexible hybrid hand to stabilize and safely grasp fragile objects.