Publications

Baker, JE & Waldron, KJ 1974, 'The CHCH- linkage', Mechanism and Machine Theory, vol. 9, no. 3-4, pp. 285-297.
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Although many studies have been carried out to determine existence criteria for different configurations of spatial linkages, no previous publication has included results for mechanisms with non-parallel screw joints. Waldron's comprehensive results for all four-bars, exclusive of those with screw joints, suggest that the CHCH- configuration is the only one likely to lead to new mobile solutions. The present paper develops the existence criteria for this linkage, using the technique of solution of closure equations. © 1974.

YEO, BP, WALDRON, KJ & GOH, BS 1974, 'Optimal initial choice of multipliers in the quasilinearization method for optimal control problems with bounded controls', International Journal of Control, vol. 20, no. 1, pp. 17-33.
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An algorithm to choose the initial multipliers optimally for quasilinearization solution of optimal control problems with bounded controls and constant multipliers is Proposed. It uses diagonal matrices of weighting coefficients in the performance index of an auxiliary minimization problem. This auxiliary performance index comprises the cumulative error in the system constraints and the optimum conditions in the original cxtremization problem. The auxiliary performance index is quadratically dependent on the multipliers for given state and control functions. The resulting variational problem leads to linear Euler equations. The computational characteristics of the proposed method are demonstrated with two numerical examples. © 1974 Taylor & Francis Group, LLC.

Baker, JE & Waldron, KJ 1970, 'LIMIT POSITIONS OF SPATIAL LINKAGES VIA SCREW SYSTEM THEORY.', American Society of Mechanical Engineers (Paper).
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A method, based on the theory of instantaneous screw axes, is presented. As well as being more direct, easier to apply and wider ranging than established techniques, the new method is capable of treating linkages with screw joints. The method may be formulated geometrically, algebraically, or numerically. The algebraic approach is used here, and four examples are given to illustrate the scope of the method.