Investigating the relationship between TIP and three-link models when the mass are varied

In Humanoid robotics field, capability to perform any task that imitates human movement has been the major research focus. One of the critical movements is the Sit to Stand (STS) motion. STS motion can be predicted using three-link (3L) robot inverse kinematic and dynamic model. 3L multi segments is quite complicated and requires high computational resources to calculate. Telescopic Inverted Pendulum (TIP) is another model that much simpler for planning and analyzing humanoid robot since it represent whole body with one single link. However it is not clear whether TIP can represent 3L multi segment robot yet. Thus, this paper objective is to find the relationship between TIP and 3L model when the mass is varied. To do so, simulation setup for 3L and TIP model is developed using MATLAB. The torque values at each joint are observed to obtain the relationship between mass and the torque. The results show that both TIP and 3L model give a similarity result where mass and torque change in linear. For every drop of mass, the torque is also decrease.