A robust output feedback strategy for liquid handling using reconfigurable robots

Abstract

Reconfigurable mobile robots have shown better area coverage property as compared to conventional mobile robots in the automation of various cleaning, maintenance, and construction tasks. These tasks may require the robots to handle viscous and non-viscous fluids in different containers. If these fluids’ sloshing effects are neglected, it can lead to spilling at undesired locations and tracking inaccuracies, which may hamper task completion and the robot's usability. This paper exploits control theory to develop a new robust output feedback technique for liquid handling using reconfigurable mobile robots. The controller and observer gains are computed through S-procedure lemma, whereas the closed-loop stability is established using Lyapunov functions. The liquid handling problem is solved without the use of additional sensors for measuring slosh variables such as the amplitude and frequency of oscillations in the liquid column. The proposed framework's usability and efficacy are validated through several experiments conducted on a self-reconfigurable cleaning robot named h-Trihex.