Study and design of a balance postural control system

Abstract

The ability to maintain a proper posture is becoming a more interesting topic as it is necessary to understand the behavior of the human body to be able to apply this knowledge to robotics and mechanics. In this project the design and study of a balance postural control system has been developed, by following a frontal modeling approach. An extensive research on biomechanical parameters has been necessary to find realistic anthropometric values to be implemented. A simplified model, based on the double pendulum, has been chosen because it allowed focusing on the basis of the balance movement. Regarding the control system, two different methods have been used. On the one hand, the Linear-quadratic regulator (LQR) has been used as it allowed to decide how much weight the controller could have, while on the other hand, a non linear controller has been studied. Moreover, a second model that included an elastic element to simulate the hip joint has been designed;to do so, a wide research on different approximations of the human body’s joints has been performed. Finally, the simulation of the different models and the numerous scenarios considered has allowed an extensive comparison determining which parameters could be neglected and which ones havea strong influence on the system dynamics.