25 The Mark 1.5 Edinburgh Robot Facility H. G. Barrow and G. F. Crawford

INTRODUCTION In May 1971 the Mark 1.5 Edinburgh robot system went on-line as a complete hand-eye system. Two years earlier the Mark 1 device had been connected to the ic L 4130 computer of the Department of Machine Intelligence and Perception. The Mark 1 (Barrow and Salter 1970) had been little more than a semi-mobile T.V. camera, with coarse picture sampling (64 x 64 points, 16 levels), a limited range of movement over a three-foot diameter circular platform, and a pair of touch-sensitive bumpers. Within eighteen months we had developed suitable basic software, and a teachable' program capable of recognizing irregular objects via the However, the restrictions upon movement, the limited range of actions which could modify the'world', and the shortcomings of the video system, made more advanced work difficult. Plans were therefore laid for the construction of the Mark 2 device. The Mark 2 robot system will possess moderately sophisticated eyes and a hand which can manipulate objects with a reasonable degree of precision. The present equipment thus represents a useable system, not yet up to full Mark 2 specification, but considerably more useful than the Mark 1. DESIGN CONCEPTS It is important that the complete system should be as self-reliant as possible. If it depends much upon human assistance to pre-process information or to put things right when they go astray, it is all too easy in one's research to avoid the central issues of a problem, and produce a'solution' which does not survive when confronted by real situations. In the Mark 1 device we implemented a suggestion from Derek Healy that when a robot is complicated and linked to a fixed computer, and its world is simple, it is better to keep the robot still and move the world. From its own point of view, the robot cannot tell whether it or the world moves, and one can simulate free movement in a restricted area.