構造や配置に基づく計測性能の最適化を考慮した装着型床反力計のひずみ解析

抄録

The importance of rehabilitation in the treatment for walking disorders due to such illnesses as strokes continues to increase. When physical therapists instruct a patient during rehabilitation, information about joint moment of lower limb is very useful. Joint moment of lower limb has been calculated by inverse dynamics applied to data obtained from a force plate and three-dimensional motion analysis system and their use conditions and measurable number of steps are limited because they must be installed at a purpose-built structure. Therefore, the wearable gait motion analysis system using mobile force plate and attitude sensor has been developed. However, structural optimization of the mobile force plate based on the ground reaction force during gait as the biomechanical evidence has not been investigated yet. In this paper, we showed a new optimum design example of the mobile force plate by applying the multi-objective structural optimization technique using finite element analysis based on strains, response surface method and desirability function. As a result of inputting each load condition by using the ground reaction force during gait, we could optimize the structure of the mobile force plate as the minimization of several dimensions based on the maximization of strains to each axis direction of the elements and nodes of maximum principle stresses. We applied optimum design variables to the finite element model and validated the effectiveness of the proposed design example. Finally, optimization of the mobile force plate for the improvement based on structure and arrangement of three-axis force sensors was attempted.