On the mechanical design of a Stewart platform-based robotic end-effector

The authors present the mechanical design of a robotic end-effector which has six degrees of freedom and was built to study autonomous robotic assembly in space. The end-effector´s design is based on the mechanism of the Stewart platform. The end-effector consists mainly of two platforms coupled by six linear actuators driven by DC motors. Position feedback is achieved by six linear displacement transducers (LDTs) mounted along the actuators to measure their length variations. Computations are performed to select proper DC motors, ballscrews, LDTs, and platform parameters so that a set of design specifications, including resolution of platform, accuracy, speed, and lifting capability, is satisfied