A vision-based robot arm with ball-throwing capability

Abstract

This paper investigates the construction and control of a robot arm which mimics human arm's pitching motion. In order for the robot to have the vision capability, like a human pitcher, a CCD webcam is added to capture target image. After image processing and analysis, controller can compute and then issue the motion commands to the robot arm motors. The vision system helps promote system's intelligence and improves pitching precision. Furthermore, placing the robot arm onto an autonomous vehicle increases its mobility. Two experiments are performed to demonstrate its throwing ability. The first one is to hit a static target, which consists of 9 prearranged rectangles. The other one is a dynamic target, which consists of an air-floating ball kept in midair using a blower. The blower is located on a remote-controlled car; therefore, the target ball moving trajectory can be changed.