Abstract
In this paper the control of an Inverted PENdulum Type Assistant Robot (I-PENTAR) in motions where the state of the system is far from the equilibrium is examined. Since the inverted pendulum is a nonlineear system, linearization near its equilibrium point must be performed for linear controllers to be used. Although this is sufficient for stabilizing the system close to the equilibrium point, degradation of the performance can be expected as the operating point moves further away from the equilibrium. This is due to the fact that static feedback gains no longer match the plant parameters. A dynamic controller with a wide operating region is desirable because there is no need for a switching control strategy with complicated switching conditions. Such a controller based on the Extended State Observer is applied to the I-PENTAR system to achieve motions that are far from the equilibrium point. In particular, the standing up motion of the I-PENTAR is tested and results are presented.
