Authors: Minhuan Guo; Dongbing Gu
Addresses: Suzhou Vocational University, Suzhou, 215104, China ' University of Essex, Colchester, CO4-3SQ, UK
Abstract: In this paper, we design a mixed H2/H∞ controller for two quadrotors transporting a cable-suspended payload. The task is to control the payload to track a predefined trajectory in a confined space. There are two challenging issues: one is the robustness of the controlled system as it is very easy to be affected by exogenous disturbances, and the other is the constrained environment in which the system is asked to pass through a door without any collision. We develop a mixed H2/H∞ controller to strike a balance between smoothing the tracking trajectory and resisting the disturbance. The controller also possesses the ability to cope with the constraints imposed on inputs and outputs. The trajectory generation is based on an offline optimisation approach by considering the output flatness of the system. Finally, numerical simulation results are provided and compared against individual H2 or H∞ controller.
Keywords: quadrotor transportation; mixed H2/H∞ control; constrained optimal control; robust control; linear matrix inequality; LMI.
International Journal of Modelling, Identification and Control, 2021 Vol.38 No.1, pp.15 - 31
Received: 11 Jan 2021
Accepted: 16 Mar 2021
Published online: 26 Apr 2022 *