I. ALEKSANDER Kobler Unit for Information Technology Management, Imperial College of Science and Technology, London, England It is now over half a decade since Joseph Engelberger wrote: 'Given a six-articulation arm of any configuration, software can be powerful enough to think only in tool coordinates. That is, a programmer concerns himself only with the tool on the end of the robot arm. He can think of the tool's frame of reference and com­ puter subroutines automatically make the various articulations move so as to accomplish the desired tool manipulation. ' As is often the case with statements of this kind, they are appealing and generally well-founded in technological feasibility. But in order to turn the prediction into reality it requires the dedication and in­ ventiveness of an international community of researchers. The object of this book is to provide a window on to some of the advances made by this community which go towards the fulfilment of Engelberger's predictions. A significant factor in the framework within which this work is being pursued is the phenomenal advance in the availability of inex­ pensive and highly compact computing power. It becomes increas­ ingly possible to imagine powerful microprocessors providing local intelligence at key points in a robot arm Uoints, gripper, etc) by being connected through a communications network and controlled by some specially designated supervisory microchip.

1 Introduction.- Robotic Practice 10; Exploiting Mathematics 11; Making Sense of Sensors 12; Computing for Design 13; Future Directions 14.- I: Sensor Information Processing.- 2 A method for grasping randomly oriented objects using touch sensing.- 18; Theory 19; Development of Sensors and Techniques 22; Examples of Applications 26; Programming 30; Error Recovery 31; An Outline Design for a Gripper with Touch Sensing 33; Conclusions 33.- 3 Method of contour recognition.- 37; The Method of Automatic Detection of Objects 38; The Method of Automatic Removal of Isolated Disturbances 43; The Method of Derivation of Contours 44; The Method of Recognizing Contours Detected 46; Discussion 49.- 4 The design of sensors for a mobile teleoperator robot.- -Teleoperator and Industrial Robotics 58; On the Proper Interface between Man and Machine 60; The QMCAI Mark 5 Robot 60; The Interface between Robot Hardware and Computer 64; Low-level Robot Control Software 66; The Sensor System 67; Layout of the Electronic Subsystems 81; Conclusions 81; Acknowledgements 83.- II: Mathematical Concerns.- 5 Constrained average path tracking for industrial robots.- 88; Equation of Motion for Mechanical Manipulator 90; Discrete-time Model of Manipulator 91; Estimation of Parameters 92; Path-Tracking Controller 96; Desired Joint Path 97; Concluding Remarks 98; Acknowledgement 99.- 6 The application of spline functions to trajectory generation for computer-controlled manipulators.- 102; Analysis 104; Discussion 109; Acknowledgement 110.- 7 Kinematic equations of robot manipulators.- 112; Geometric Modelling of a Manipulator 114; Kinematic Modelling of a Manipulator 123; Conclusion 129.- 8 Solution of kinematic equations for robot manipulators.- 131; Coordinate System of Robot Arm 132; Solution of Arm Motion 133; Solution of Wrist Motion 138; Solution for Robot Manipulators 143; Example: RRR Arm with a Modified Euler Wrist 145; Conclusion 147.- III: Practical Concerns.- 9 A strategy to achieve an assembly by means of an inaccurate, flexible robot.- 152; The Hypotheses of Work 153; Assembly Achievement 155; Experimentation 167; Conclusion 176.- 10 Trajectory planning for a multi-arm robot in an assembly task.- 179; Definitions and Hypotheses 180; Environment Modelling 183; The Path Search 185; Experimentation 187; Conclusion 195.- 11 Cooperation of two manipulators in assembly tasks.- 197; A Functional Classification of Assemblies Using Two Arms 198; Description of the Experiments Carried Out 203; Problems Set by Using Two Arms 211; Conclusion 214.- IV: Computer Aids to Robot Design.- 12 A CAD system for programming and simulating robots' actions.- 223; The Robotic Facilities of CATIA 223; Using the Robotic Facilities 232; Conclusion 237; Acknowledgements 246.- 13 The development of a suite of programs for the analysis of mechanisms.- 249; Program Outline 250; Proposed Method of Operation 253; Procedural Example 254; Conclusions 276; Acknowledgements 276.