Ball dribbling is a central element of basketball. One main challenge for realizing basketball robots is to stabilize periodic motions of the ball. This task is nontrivial due to the discrete-continuous nature of the corresponding dynamics. The ball can be only controlled during ball-manipulator contact and moves freely otherwise. We propose a manipulator equipped with a spring that gets compressed when the ball bounces against it. Hence, we can have continuous-time control over this underactuated Ball-Spring-Manipulator system until the spring releases its accumulated energy back to the ball. This paper illustrates a systematic way of planning such a modified dribbling motion, computing an analytical transverse linearization and achieving orbital stabilization.

Ball dribbling is a central element of basketball. One main challenge for realizing basketball robots is to stabilize periodic motion of the ball. The task is nontrivial due to the discrete-continuous nature of the corresponding dynamics. This paper proposes to add an elastic element to the manipulator so the ball can be controlled in a continuous-time phase instead of an intermittent contact. Optimal catching and pushing trajectories are planned for the underactuated system based on the virtual holonomic constraints approach. First experimental studies are presented to evaluate the approach.

Ball dribbling is a central element of basketball and a main challenge for creating basketball robots is to achieve stability of the periodic dribbling task. In this paper two control designs for ball dribbling with an industrial robot are compared. For the two strategies, the ball position is determined either through force/torque or visual sensor feedback and the ball trajectory is predicted with a recursive least squares algorithm. The end effector trajectory for each dribbling cycle is generated based on the predicted ball position/velocity at the dribbling height and the estimated coefficient of restitution. For both tracking approaches, dribbling for multiple cycles is achieved. The vision-based approach performs better as compared to the force/torque-based approach, in particular for imprecise estimates of the coefficient of restitution.

Building a basketball robot is a recently launched project at the Institute of Automatic Control Engineering (LSR) for investigating fast manipulation with non-negligible dynamics and changing contact situation. This study presents one of the main preliminary results of the project which is balancing a basketball on a plate using a six degrees of freedom serial industrial robot based on pure haptic information. The Ball-On-Plate system has been one of the classical applications of control theory and many studies have been conducted on this issue. However, most of these studies employed vision systems to update the current state of the ball on the plate. In this paper, the concept of balancing a ball on a plate purely based on haptic information is discussed. The velocity of the basketball which rolls on a plate is estimated based on the force data measured by a force-torque (F/T) sensor mounted on the end-effector and the proposed control scheme brings the basketball back to a still standing on the plate. Experimental results are presented to validate the efficiency of the proposed control scheme.