C. B. Besant

Development of a profile gauging sensor

A non-contact inspection system that can automatically assess the quality of complex engineering components such as turbine blades, has been identified by the aeroengine industry as a requirement in automating the process of proof inspection. This requirement led Rolls-Royce plc. and Imperial College to investigate non-contact measurement techniques and to devise an automated system based on such technology. The system in its final form, will provide an integrated CAD/CAM-based concept that will enable design and manufacture data relating to complex three-dimensional objects to be compared and assessed.

Job-shop scheduling using certain heuristic search algorithms

This paper presents a family of sub-optimal algorithms based on the A* heuristic search algorithm, aimed at solving the general job-shop scheduling problem. A methodology is suggested for algorithms that require adjustable memory resources, by compromising algorithmic admissibility. Different possibilities for (admissible or non-admissible) heuristic estimates are suggested and dynamically weighted heuristics are introduced to the job-shop scheduling problem, with good results. Bottleneck scheduling is introduced within this problem-solving scheme, proving a base for more powerful heuristics. In terms of solution nearness to optimal and speed, the techniques investigated generally compare favourably with similar work in this field.

A CAD/CAM system for die design and manufacture

The manufacture of directionally solidified cast turbine blades relies on the precise casting of wax patterns of the actual turbine blade. This, in turn, requires the design and manufacture of a complex die. A CAD/CAM system is presented specifically for producing manufacturing information for dies based on basic data defining the shape of a turbine blade. The system is based around a UNIX graphics workstation which forms part of a CIM system being developed as part of an SERC Teaching Company based at Rolls-Royce plc, Derby.

Process variables determining the dimensional and metallurgical properties of directionally solidified, cored turbine blades produced by investment casting of super-alloys

The investment casting process for the manufacture of directionally solidified, cored turbine blades is described. The dimensional and metallurgical properties of blades produced by this process is subject to variations which can result in long lead times in development and scrap during production. The process variables that determine the dimensional and metallurgical properties have been identified and classified in order of importance. The objective of the research is the formation of a database of process variables that can be used as a basis for control of the casting process and for predicting the final geometry as a result of the process.

A graphics environment for CIM applications

Programmers in graphics applications have come to expect a standard of pre-written software to provide the basic building blocks for their specific needs. Computer-aided engineering (CAE) now requires a similar standard of software to provide an integrated platform with higher levels of graphics functions, solid modelling facilities and user interfaces. PANACEA is a research tool which has provided this base foroa number of CAE applications programs.

Reduction in the development lead times of complex investment castings by the application of CIM technology

The development costs associated with complex investment casting processes for components, such as turbine blades, are large due to long lead times. A CIM system is described which has been developed, in collaboration with Rolls-Royce, to substantially reduce lead times in the development of precision cast turbine blades.

A versatile six degree of freedom robot

This paper describes a prototype six degree of freedom 8kg capacity robot constructed to meet the needs of robotics research at Imperial College. With future robot requirements in mind, the robot control system was developed in collaboration with R.D. Projects Ltd.