A vision system with multiple cameras designed for humanoid robots to play table tennis

Two humanoid robots are used to play table tennis with each other. For each humanoid robot, three cameras and a computer are equipped to form a stereovision system and a monocular vision system. The stereovision system consisting of two smart cameras and a computer measures the 3-dimensional position of the table tennis ball. It adopts parallel processing mode in order to realize hundred frames level measurement per second. A high-speed digital camera and the computer compose the monocular vision system, which measures the pose of the robot relative to the table via a color mark attached on the robot. The two smart cameras in each stereovision system are synchronized via I/O signals. The vision systems for the two robots are synchronized by time verification. Experimental results verify the effectiveness of the designed vision system and the proposed methods.