Robot Manipulators

Abstract

The most important types of manipulators or end effectors for smart robots are devices that produce certain types of controlled motion. More than a hundred different companies around the world now make manipulator arms. They range in size from tiny arms for handling near-microscopic hybrid circuit components up to machines that can lift objects weighing several hundred pounts four or five meters into the air as shown in Fig. 6–1. Typical positioning accuracies are about one millimeter and speeds are about one to two meters/second. Older arms resemble a tank turret with a hand on the end of a telescoping pipe. Modern ones usually have five or six rotary joints in series, and move in somewhat the same way as a human arm does. Several “cartesian” manipulators have appeared on the market that have three orthogonal sliding joints for rigidity and ease of control. An arm is usually designed for a particular type of activity such as spraying, simple handling, or precise assembly.