The previous paper by the same authors (Robotica 2, Part 2, pp. 93–103 1984) was concerned with the application of logic programming to the generation of paths for robots. This paper is dealing with the PIGS system for robot problem-solving in generating plans for robots. The system avoids the overhead of generating a new set of facts for each state considered. A computer-type control is adopted not only to generate a simple sequence of actions to be performed by the robot, but also to enable the robot to follow an accurately defined path. A suitable plan of action of a robot problem-solving system is generated. The system is written in the PROLOG language and acts as a robot plan generator that is integrated with a path finding procedure in order to avoid collisions whilst plans are being implemented.

This paper describes an algorithm which recognizes the position and the orientation of a structural industrial part, such as a crankshaft, utilizing the relationships between its elementary blobs. Crankshafts are arranged tightly and piled up in multiple layers and their image from above includes regions (i.e. pictures) of crankshafts not only of the current top layer but also of the lower ones; it thus becomes complicated. First, the algorithm carries out the connectivity analysis for an input binary image, and then extracts elementary blobs by applying a line fitting procedure on every sequence of boundary pixels of connected regions. Next, each blob is judged to determine to which component of a part it corresponds, using the size model. Then the relationships (distances and orientations) between blobs are examined, using their relational models, and a group of blobs of one part is recognized. Its position and orientation are calculated simultaneously. This model matching algorithm is implicitly included in the procedures.

The control of a robot manipulator with force sensors in the gripping tips is considered. The sensors measure three components of the force. Complicated motions of the manipulator are complied from basic movements, and the paper describes how the operation of grasping an arbitrarily positioned object is constructed from the basic movements. A mathematical model of the basic procedure of keeping contact with the object is considered.

The increased demand on the performance and efficiency of industrial robots, has led to the design of sophisticated control systems. Such control systems require an accurate dynamic model of the system. A commonly used method of modeling an industrial robot, involves the description of a set of dynamic equations, relating actuator torques to loads and accelerations. These equations are generally quite complex and inconvenient for implementation on digital computers.

Another method often used for identification, is the ‘indirect method’, in which the transfer function is obtained in two steps. The discrete time model is first derived from samples of the input and output measurements, which is then transformed to the continuous-time model. A limitation of this method is that it requires the excitation to be of the ‘persistently exciting’ type, thus precluding the application of simple inputs like the step signal.

This paper describes a ‘direct’ method for identification of an ‘industrial robot’ from samples of input and output observations. Results of modeling an industrial robot and two simulations are presented. One of the simulations, and the industrial robot uses the step input as excitation. The other example was excited with an exponential input.

The technical, managerial, organisational, economic and labour factors found to be important in an empirical study of more than forty firms adopting or considering robots, are outlined. Specific problems, arising from the requirements for managing integrated mechanical, electronic and computational systems, and the novel choreographic approach to production embodied in robots, are posed by the introduction of this new technology. For their effective solution, these problems demand an increased level of competence and expertise, at all levels from the managerial to the technical. But robots are just one part of modern automation, and in the future programmable automation – the integration of computer technology, robotics and conventional automation – will increasingly become the competitive standard in manufacturing industry. The introduction of such new technological standards, though forced by competitive pressures, will, however, require extensive institutional, organisational, and disciplinary adaptation if their full potential is to be realised and the UK is to remain one of the leading industrial nations.