Multibody dynamics of mechanism with secondary system

ii To my mother and grandmother who always support me with constant love and pray, my wife who is the anchor of my life and the memory of my father iii ABSTRACT Recent advances in predictive dynamics allow the user to not only predict physics based human motion simulations but also determine the actuation torques required to achieve those motions. The predictive dynamics approach uses optimization to predict motion while using many task based, physics based, and environment based constraints including the equations of motion. Many tasks have been simulated using this new method of predicting and simulating digital human motion, e.g. walking, running, stair climbing, and box lifting. In this research, we develop a method to predict the motion as well as effect of external equipment hanging on the digital human. The proposed method is tested on a simple case of a two degree of freedom serial chain mechanism with a simple passive system to behave as external equipment. In particular, the passive mass is assumed to be attached to the two links system with a spring and damper. Three different initial position cases are developed and tested to calculate motion and reaction force of spring and damper system. The results of the proposed method are compared with the results obtained by integrating the equations of motion of the full three degree of freedom system. Figure 3-7 Approximate solution of equations of motion VS SimMechanics solution with time step 0. Figure 3-8 Approximate solution of equations of motion VS SimMechanics solution with time step 0. viii Figure 3-12 ODE solution of equation of motion VS SimMechanics solution with time step 0.