A Solution Method for Predictive Simulations in a Stochastic Environment

This short communication describes a method to solve predictive simulations of human movements in a stochastic environment using a collocation method. The optimization is performed over multiple noisy episodes of the trajectory, instead of a single episode in a deterministic environment. Each episode used the same control parameters. The method was verified on a torque-driven pendulum swing-up problem. A different optimal trajectory was found in a stochastic environment than in the deterministic environment. Secondly, it was applied to gait to show its application in human movements. We show that nonzero minimum foot clearance during swing is energetically optimal in a stochastic environment. The amount of clearance increased with the noise amplitude.