At Imperial College, the author has invented a form of universal gripper comprising two slightly separated ‘fingers’, each consisting of an array of 8 by 16 closely spaced pins which can ride vertically up and down independently of each other. Lowering the gripper over an object pushes some pins out of the way, so creating ‘customised’ fingers which mould round and fit the part. To grasp objects, either the two (slightly separated) fingers can be brought together to grip an object externally, or else they can be moved slightly apart (from a ‘closed’ position) for an internal grip. In addition, feedback from each pin of the gripper can provide tactile information about an object.

Even as the first industrial robot started earning its keep, researchers were dreaming of using robots in servicejobs, intimately serving human mentors as Isaac Asimovwould have had it. But that was not to be. Initially therewas a paucity of appropriate technology. Then the barriers became economic and institutional.

These barriers will be discussed to set the scene. The discussion then will focus on a spectrum of technologythat has been channelled into a cost-effective commercialproduct. HelpMate utilises an array of sensors andsensor fusion to succeed as a courier in multi-storeyedcluttered hospitals. Our advice for all researchers whowould have robots serve in health care is: “Get out intothe real world as soon as you can”.

This paper presents a complete derivation of the combined flexural-joint stiffness matrix and the elastic deformation field of flexible manipulator arms treated in a three-dimensional fashion. The stiffness properties are derived directly from the differential equations used in the engineering beam theory. The expressions developed here can readily be used in the modeling, control and design of light weight flexible robot manipulators. A two-link arm is used to formulate these expressions and the results can be generalized to n–link manipulators. The stiffness matrix for a robotic link element in 3-D is of the order of 12 X 12, and for an n–link robotic arm the total elemental and system stiffness matrices will be of the order of the (12n X 12n) and 6(n + 1) X 6(n + 1), respectively.

We describe a sensor integration system which we have designed and implemented for a large fully-integrated flexible assembly machine. The machine was developed by a consortium to explore the design and implementation issues involved. The sensor integration system was designed for execution on a multiple transputer architecture, and co-ordinates all the sensory information in the machine. It uses the concept of virtual sensing to provide sensory data at an appropriate level of abstraction to the machine supervisor, which controls execution of the assembly tasks.

Computer Vision is essentially concerned with emulating the process of seeing, naturally manifested in various higher biological systems,1–4 on a computational apparatus, and is consequently part of the Artificial Intelligence field within the sub-category of Machine perception. Seeing has to do with making sense of image data acquired through an optical system and subsequently dealt with at increasing levels of abstraction and association with known facts about the world. The spectrum of interest in Computer Vision ranges from attempting to answer basic questions concerning the functionality of biological vision systems, particularly human, at one end, all the way to enhancing the reliability, speed and cost effectiveness of specific industrial operations, particularly component inspection and vision driven robotic manipulation. The main bulk of interest is in the middle, where the quest for generality pushes interest towards biological vision systems with their demonstrated effectiveness in a wide range of environments, some hostile, whilst the need for economic viability and timeliness in relation to particular application pushes interest towards finding workable algorithms which function reliably at high speed on affordable apparatus.

This paper is addressed, in somewhat tutorial style, at clarifying, by examples of work in the area, the issues surrounding application oriented robotic vision systems, their assumptions, strengths, weaknesses and degree of generality, and at the same time putting them in the context of the overall field of Computer Vision. In addition, the paper points to directions of development which promise to provide powerful industrial vision tools at an acceptable price.

This paper describes a primitive environment recognition system for advanced robots. The system can recognize the location, configuration and distribution of 3-D objects in an object space (4m×4m×2.5m) using an ultrasonic imaging method. As an experiment, we have tried to develop the recognition system for the distribution of standing persons. First, this system was tested by mechanical scanning in order to obtain a satisfactory result. Next, we have investigated the electronic scanning method. A transmitter built for testing was composed of twenty-one ultrasonic transducers (40 KHz) built into a 2-D array. The characteristics supported by measurements have agreed well with the theoretical results. Therefore, it has become clear that the ultrasonic imaging system using an electronic scanning method can be applied to environment recognition.

This paper describes a compact assembly sequencer for automatic robotic assembly using a configuration space-based path planner. Connection graph of the assembly is constrained by the feasibility information made available from the analysis of local disassembly paths tried by the robot's path planner. Free space of the robot performing assembly is explicitly used to generate the disassembly constraints. We show with the help of a ball pen assembly how the sequencing is performed with this representation.

This paper presents a method for the automatic generation of robotic assembly sequences based on the verification of a disassemblability for a part to be disassembled. To derive the disassemblability of a candidate part, we first inference collision free assembly directions by extracting separable directions for the part and calculating the separability which gives information as to how the part can be easily separated. Using the result, we determine the disassemblability defined in terms of the separability and stability costs. The separability cost represents a facility of the part disassembly operation, while the stability cost represents a degree of the stability for the base assembly motion which gives a guidance for design of jig/fixture. The proposed method provides a potentially local optimal solution for finding a cost effective assembly plan, and the feasibility of generating robot motion programs by evaluating separable directions in flexible manufacturing applications. A case study is given to illustrate the concepts and procedure of the proposed scheme.

Force control of walking machines is essential in a natural soft and uneven terrain. A load adaptive PI force control method for the hydraulic actuation system of MECANT I has been developed. The I term of the controller is changed according to the desired load. Force control satisfies the support requirement also when a leg penetrates the terrain. A method to distribute support forces in an optimal manner has been developed. A rule based altitude controller and a dead-zone and saturation based attitude controller calculates the desired body forces. Walking tests on uneven wet sand fields show the useful applicability of the method.

A method is described to convert information available at manipulator programming level into trajectories which are suitable for tracking by a servo control system. This process generates trajectories in real time which comply with general dynamic and kinematic constraints. Tracking accuracy will depend mainly on the acceleration demand of the nominal trajectory setpoints - the actuator output demands, in particular, must remain bounded. Our scheme takes into consideration at the trajectory computation level the dynamics of the underlying system, dynamically available information acquired through sensors, and various types of constraints, such as manipulators. It has been developed in the context of a multi-manipulator programming and control system called Kali and developed at McGill University.