Exterior lighting design by computer algebra

Conventionally, exterior lighting design for, say a playground or apron etc, has relied on two popular methods, the lumen method and the more accurate point-by-point method. Both methods depend extensively on human experience to arrive at the final layout by repetitive trial-and-error. The design criterion is to achieve a desirable lux level as uniformly as possible. In this paper, a new design methodology has been developed based on the point-by-point method. By using new techniques in computer algebra, an optimal design that fully meets the design criterion can be achieved automatically by the optimisation of an error function. A review of computer algebra on different platforms and the development of a new three-dimensional vector approach to the point-by-point method, which are independent of geometric coordinates, are also discussed.