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An adaptive control system is proposed in which a given amount of tool wear is allowed per operation. The objective of the control system is to machine a certain feed distance in the minimum time using no more than the wear allowed and working within the conventional adaptive control constraints. The average rate at which the operation progresses can thus be regulated by appropriately setting the wear target. The adaptive control system has been applied to the control of a lathe performing a simple bar turning operation. An on-line computer receives transducer responses, calculates and issues feed and speed corrections. The optimization policy requires the tool wear rate to be estimated while cutting and in this work the estimation was made from the cutting process variables including the tool-work thermocouple voltage. Workpiece disturbances in the form of hardness changes were introduced and the experimental responses of the control system to these disturbances are presented. The success of estimating wear rate on a sample of the controlled tests is also presented. [ABSTRACT FROM AUTHOR]

A component of the direct operating cost of aircraft is that associated with the manufacturing cost. This affects depreciation, interest, insurance and maintenance charges. By relaxing the requirements for aerodynamic surface smoothness the manufacturing cost can be reduced at the expense of an increase in drag and corresponding fuel costs. This work is part of a study to examine this multidisciplinary problem. Only isolated turbofan nacelles are considered. The costs associated with assigning different tolerance levels to the feature dimensions on nacelles are assessed. A statistical procedure is employed to estimate the cost-tolerance relationship for eleven features involving gaps, steps, surface profile and fastener flushness. This procedure requires actual manufacturing and cost source data. A knowledge of the cost-tolerance relationships is useful in a concurrent engineering context. It will allow aerodynamicists to optimise surface smoothness in consultation with production engineers, thus achieving the best compromise between cost and drag. [ABSTRACT FROM AUTHOR]

A method for the design of garments at a workstation is proposed. An underlying body form analogous to a trade mannequin is first represented in the computer. Garment panels are considered to be surfaces of complex shape, whose fit with respect to body form may vary over the surface. A method of easy entry of data for representing panels is proposed, whereby fit around panel edges can be defined. The problems of controlling fit in the interior of panels is considered and a scheme is proposed which accomplishes design with economy of effort from the designer. [ABSTRACT FROM AUTHOR]