| المستخلص: |
The aim of this research is to use biped model, with moderate complexity, to predict and capture some features of gait (walking and/or running) of a human in the sagittal plane such as types of gait, preferred transition speed, and effect of restriction of torso movement, and then validate the simulation results using results available in the previous experimental gait studies. The detection of gait events and phases is an essential starting point for nearly all aspects of gait analysis, diagnosis, rehabilitation, and for building walking aid devices. The biped model helps in distinguishing the pattern of normal gait and compares it to abnormal gaits. The equations of motion are developed to describe the motion of the biped models. Then, the problem is formulated as a dynamic numerical optimization problem to predict the optimal gait of the biped model with rigid torso. The model incorporates the effects of both physical and kinematics constraints of the human locomotion. The optimization satisfies the constraints while minimizing the objective function. The optimization seeks to minimize the cost of transport. Despite the fact that the model used is simple and lacking many features of human walking like knee flexion and ankle joint, the gait optimization for this simple model predicts many features of human locomotion. The optimization converges to walking or Pendular run or impulsive run gaits subject to the speed and step size of the biped motion. Optimization results show that, walking gait is optimal at low speed and small step length. Pendular run is the optimal gait for intermediate step length and speed. The impulsive run is optimal at high speed and large step size. Moreover, the predicted transition speed from walking to running agrees with those reported in the literature for human gait. This thesis also explains how the torso angle changes during walking gait and the effect of walking with restricted torso. In this study, the results show that the behavior of the torso movement during gait can affect the kinematic pattern of lower limbs.
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