Sliding Mode Control for Mixed Conventional/Braking Actuation Mobile Robots

TL;DR

This paper introduces a sliding mode control approach for a novel mixed actuation mobile robot that combines conventional and braking mechanisms, aiming to improve controllability and robustness in under-actuated systems.

Contribution

It presents a new control strategy using sliding mode control for a mixed actuation mobile robot with discontinuous dynamics, validated through experimental parking results.

Findings

Successful parking control demonstrated experimentally.

Robustness of control against actuator discontinuities.

Effective handling of under-actuated dynamics.

Abstract

The Mixed convention/braking Actuation Mobile Robot (MAMR) was designed to tackle some of the drawbacks of conventional mobile robots such as losing controllability due to primary actuator failures, mechanical complexity, weight, and cost. It replaces conventional steering wheels with braking actuators and conventional drive wheels with a single omni-directional wheel. This makes it fall under the category of under-actuated mobile robots. The brakes have only two states, ON and OFF, resulting in discontinuous dynamics. This inspires the use of a discontinuous control law to control the system. This work presents a Sliding Mode Controller (SMC) design to park the MAMR system from a given initial configuration to a desired final configuration. Experimental results are presented to validate the parking control of the MAMR.