Formulation of Ergonomic Design Problem with Considering the Response to Individual Difference

Abstract

This paper proposes a formulation method of ergonomic design problem so as to support the decision making of designers. The optimization problem for each participant is formulated as a multi-objective optimization problem. In addition, the optimization problem for all participants is formulated based on different ergonomic design strategy for considering individual difference: a) design for average participants (Strategy A), b) design for weak participants (Strategy B), and c) design for divided clusters (Strategy C). The regret is defined as the difference from the objective function value of optimum solution for each participant. Then, the ergonomic design problems for three different strategies are formulated as follows; a) strategy A is formulated as the minimization of the average regret, b) strategy B is formulated as the minimization of the maximum regret, and c) strategy C is formulated as the minimization of average regret for divided clusters. The proposed method is applied to the design problem of cylindrical diameter for power grip. The cylindrical diameter is the only design variable, and the average pressure and the coefficient of variance are objective functions. From the result of optimization, it is found that the average regret based on the strategy C is significantly lower than the other strategies. In addition, the average regret based on the strategy A is significantly lower than that of the strategy B; while the maximum regret of the strategy A is higher than that of the strategy B.