Smooth Planning of Catch-to-Throw Movements for Robotics Systems Through Continuous C1 Trajectory Generation and State-Conditioned Release.

Abstract

Traditional robotic catching and throwing process chains, often create a pause time of more than 300 ms by dividing catching and throwing into two consecutive steps, and inadequately utilize the post-grasping kinetic state. This paper presents a unified catching and throwing (UCT) process framework that eliminates this discontinuity by using the joint position and velocity (qc, vc) measured during grasping confirmation as the initial condition for a Hermite-type piecewise cubic launch trajectory. A six-state finite automaton coordinates the sequence, transitioning from catching to launch in less than 5 ms while maintaining continuity (C1) to avoid velocity discontinuities. The gripper dynamics are represented by a first-order hold profile, and a Jacobian-based release velocity is coupled to a ballistic flight model for target prediction. The framework was evaluated in over 150 Drake simulations using a KUKA IIWA 14 manipulator. The results showed an overall success rate of 87.3%, an active cycle time of 0.854 s, and an average throw error of 41 mm at a target distance of 2.5 m. Compared to a reference analytical sequential method, the UCT framework reduced the cycle time by 34%, with the improvement primarily due to the elimination of the stop-start phase between capture and throw. The proposed framework is positioned as a practical level 2.5 architecture within a five-level taxonomy of capture-to-throw integration and provides a basis for future hardware implementation of continuous dynamic manipulation.