Observer Design for an Inertia Wheel Pendulum with Static Friction

TL;DR

This paper develops a state observer for an inertia wheel pendulum accounting for static friction modeled by the Stribeck effect, using probabilistic model selection to improve estimation accuracy.

Contribution

It introduces a novel observer design that incorporates static friction effects and probabilistic model switching for better state estimation in inertia wheel pendulums.

Findings

Observers effectively estimate states despite static friction.

Probabilistic model selection improves estimation accuracy.

Experimental validation on a laboratory setup confirms effectiveness.

Abstract

A state observer design for the inertia wheel pendulum considering static friction of the actuated inertia disc is presented. The frictional force is modeled by the Stribeck effect, with two separate differential equations describing the sticking and non-sticking system, respectively. The transition between the two scenarios is in general determined by a static friction condition. Three proposed observers are designed for both the sticking and non-sticking model. Depending on the probability of the respective model given a current measurement, the more likely is selected for state estimation. The performance is demonstrated on a laboratory demonstrator, where the observers including the proposed probabilistic model selection are compared.