Effect of preliminary motions on agile motions

Robots must complete motions in a short time in uncertain and variable real world environments. However, uncertainty in the real world has only rarely been considered in studies of agile motions by robots. Consequently, methods for agile motions incorporating uncertainty must be proposed. Preceding agile motions, human preparatory motions (preliminary motions) are often observed. For insight, we specifically addressed human preliminary motions as preparation for agile motion. The effect of preliminary motions on human agile motions has been studied in sports biomechanics. However, no general model of preliminary motion has been proposed. Consequently, findings related to human preliminary motions are difficult to apply to robots. Therefore, we proposed a numerical model of preliminary motions to verify the effect of preliminary motions on robots´ agile motions in numerical simulations. Using simulations, we investigated the completion time for reaching motions by simple robot arms. Results showed that robots can prepare and move quickly to an uncertain target using our proposed method of preliminary motions.