Motion Trajectory Estimation of a Flying Object and Optimal Reduced Impact Catching by a Planar Manipulator*

Throwing and catching are fundamental motions for human beings, and may be applied for advanced human and robot collaborative tasks. Since catching motion is more difficult than throwing for a robot, this study deals with reduced impact catching of a flying object by a planar manipulator. The estimation of the object's trajectory is improved by the Kalman filter and the least squares fitting is proposed to accurately predict the catching time, position and velocity of the manipulator. To achieve reduced impact catching, the minimization of the total impact force in x and y-directions is proposed as an optimization problem. The fifth degree non-periodic B-spline curve is implemented to achieve smooth and continuous trajectories in the joint space. The effectiveness of the proposed approaches are demonstrated by simulation and experiment.