Robust system design for process control simulation studies and analysis using taguchi method

摘要

The Taguchi method is a powerful problem solving technique for improving process performance, yields and productivity. It reduces scrap rates, rework costs and manufacturing costs due to excessive variability in process. Most of the robust design research in the literature focuses on problems with static responses. This research investigates robust design problems with dynamic responses. We present a fully automatic temperature control system used to control the temperature of a water heater using the PSpice temperature sensor model. The function of the electronic circuit is to maintain the temperature of the water bath to a set value i.e. target value. Robust design is an important method for improving product or manufacturing process design by making the output response insensitive (robust) to difficult to control variations (noise). For analysing robust design experiments with dynamic systems, Taguchi proposes a two-step optimization procedure to identify the 'optimal' factor settings that minimize the average quadratic loss. In this paper we show that Taguchi's orthogonal approach is appropriate. An integrated approach of circuit simulation experiments based on Taguchi's OA design of experiments and statistical analysis using MINITAB/ANOVA for the reduction of functional variation is discussed to process the control system. The results show a significant improvement for the S/N ratio sensitivity. Thus the confirmation test simulation run/hardware may be used for the intended optimal robust design system. This present technique has tremendous potential and scope in product/process design and the research and development of an electronic instrumentation. Hence, it is useful to manufacturing industries.