Friday, 16 December 2011

Forthcoming Automatica paper: Multiplexed MPC

Keck Voon Ling, Jan Maciejowski, Arthur Richards, Bing Fang Wu, Multiplexed model predictive control, Automatica, Available online 15 December 2011, ISSN 0005-1098, 10.1016/j.automatica.2011.11.001.

Abstract: This paper proposes a form of MPC in which the control variables are moved asynchronously. This contrasts with most MIMO control schemes, which assume that all variables are updated simultaneously. MPC outperforms other control strategies through its ability to deal with constraints. This requires on-line optimization, hence computational complexity can become an issue when applying MPC to complex systems with fast response times. The Multiplexed MPC (MMPC) scheme described in this paper solves the MPC problem for each subsystem sequentially, and updates subsystem controls as soon as the solution is available, thus distributing the control moves over a complete update cycle. The resulting computational speed-up allows faster response to disturbances, which may result in improved performance, despite finding sub-optimal solutions to the original problem. This paper describes nominal and robust MMPC, states some stability results, and demonstrates the effectiveness of MMPC through two examples.

Keywords: Predictive control; Distributed control; Multivariable control; Periodic systems; Constrained control

Thursday, 15 December 2011

Recruiting again! PhD opportunity on Micro Air Vehicle navigation

UPDATE: this post has been filled.

A fully-funded studentship is available for a PhD on the topic of autonomous indoor flight of a Micro Air Vehicle (MAV) using computer vision. The focus of the project is on the guidance, sensing and control aspects of the problem. It will build on prior work on visual SLAM and MAV control, and off-the-shelf platforms will be used for experiments. In particular, the project will seek to optimize trajectories and motions for the use of vision as a navigation sensor. The work will combine analysis, numerical simulation and hardware experiments. The studentship is supported by dstl (Defence Science and Technology Laboratory: ) and is part of a larger activity to develop future capabilities for building exploration in hazardous environments.

The studentship will be held in the Department of Aerospace Engineering, part of Bristol’s Faculty of Engineering. The project will be run in collaboration with the Department of Computer Science and will be affiliated with the Bristol Robotics Lab, utilizing the large indoor flying arena for experiments. Stipends will be at the standard level of £13,590 p.a. plus a top-up of £3,000 p.a. The project is aiming to begin in early 2012.

The successful applicants will all hold good (minimum 2:1, preferable first class) first degrees in engineering, robotics, computer science, mathematics or a related discipline. Experience in one or more of: computer vision; flight mechanics; control; or numerical optimization would be highly desirable. Due to funding restrictions, only EU nationals are eligible for this studentship.

For more information, please see the pages of the academic supervising team, listed below. For general enquiries, please contact Arthur Richards, whose contact details can be found on the page below. To apply, visit . On your application form, identify “PhD in Aerospace Engineering” as your chosen degree programme, “Flying with Vision” as your desired topic and Dr Arthur Richards as your proposed supervisor. Please use the “Proposed Research” section to discuss your interest in this particular topic.

- Andrew Calway:
- Walterio Mayol-Cuevas:
- Arthur Richards:
- Tom Richardson: