Mathematical modeling of human gait based on a five-link anthropomorphic mechanism using optimization methods

The problem of human gait modeling is considered. A flat anthropomorphic mechanism with five weighty links describing person's legs and body is used to describe human locomotion. The hands movements are not considered. The control is impulse, and the mechanism moves along a ballistic trajectory from the beginning to the end of the interval. A single-support motion with ground linked support leg is described by the model. The five generalized coordinates that describe the angles deviation in a joints from the vertical characterize the mechanism position. To model a real gait, when calculating the initial angular velocities vector, it is proposed to minimize the residual that guarantees the mechanism passage through all points of a given trajectory. Also, mass-inertial characteristics determine the anthropomorphic mechanism, but the modeled person's exact values are unknown. To improve the modeling accuracy, it is proposed to calculate the values of these quantities by minimization. With constrained minimization the average deviation from real angles is 7.25∘. With unconstrained minimization the average error is 3.3∘, but the mass-inertial char- acteristics may take incorrect values.