Distributed Model Predictive Control for cooperative floating object transport with multi-vessel systems

Significance 

Autonomous technology is becoming popular by the day and has mainly been applied for the development of autonomous vehicles. Recently, this novel technology has found its way into the marine world with the development of the Autonomous Surface Vessel (ASV). ASVs have been developed specifically for the purposes of improving the safety and efficiency of waterborne transport and have grown to one of the hottest research topics. Reputable literature has demonstrated that compared to an individual ASV, greater efficiency and operational capability can be realized by groups of ASVs operating in a coordinated fashion. The technicalities of operating an ASV vary largely from those of operating a robot inland in terms of dynamics and control constraints. Further, formation tracking, i.e. connecting ASVs to an object using physical connectors; say ropes, has been shown to yield better results. This technique aims at controlling the vessels to maintain a prescribed configuration and to follow predefined trajectories. Unfortunately, collision avoidance is usually not taken into account, or only considered the conflicts among the formation mates.

Overall, noteworthy studies have shown that when the ASVs are connected to the object, changing the formation shapes to avoid obstacles is impossible. Shortfalls such as this one set the impetus for further research. On this account, researchers from the Department of Maritime and Transport Technology at Delft University of Technology: Professor Linying Chen, Dr. Hans Hopman and Dr. Rudy R. Negenborn, proposed to resolve the encountered control problem of cooperative floating object transport, i.e., utilizing a team of ASVs to transport a larger floating object, such as a large vessel, barge, or offshore platform. Their work is currently published in the research journal, Ocean Engineering.

To begin with, the researchers first described the cooperative object transport system. Subsequently, the dynamic model of an ASV and a model of towline were introduced. Here, the control strategy for object transport was proposed. The researchers then designed a multi-layer cooperative control scheme, following which an ADMM based DMPC framework was proposed to reach consensus on the following actions to be taken among the controllers. Eventually, the scenarios in which the proposed cooperative system moves a large vessel sailing inbound the Port of Rotterdam were simulated to show the effectiveness of the proposed method.

In their approach, the cooperative transport problem was divided into three sub-problems, trajectory tracking of the object, control allocation, and formation tracking of the ASVs. Overall, the results obtained showed that the proposed cooperative system could transport the floating object along a predefined trajectory and avoid potential static and dynamic obstacles.

In summary, the study focused on the cooperative floating object transport, i.e., a group of ASVs coordinate their actions to transport floating objects. Professor Linying Chen and colleagues proposed a formation-based cooperative object transport system with a multi-layer control structure. In a statement to Advances in Engineering, Professor Linying Chen said that their approach would ultimately lead to methods that could become useful for moving large vessels, barges, and off-shore platforms in future ports where both human-operated and autonomous vessels exist.

About the author

Dr. Linying Chen is an assistant professor at the School of Navigation, Wuhan University of Technology, Wuhan, China. She received the B.Sc. degree in maritime administration from Wuhan University of Technology and the B.Sc. degree in international economics and trade from Wuhan University, Hubei, China, in 2011. She obtained her M.Sc. degree in Traffic Information Engineering and Control from Wuhan University of Technology in 2014. Sponsored by the China Scholarship Council, Linying Chen started her PhD research and got her Ph.D. degree in 2019 at the Department of Maritime Technology and Transport, Delft University of Technology. During her PhD research, she worked on the concept of Cooperative Multi-Vessel Systems for improving safety and efficiency of waterborne transport systems.

Dr. Linying Chen has well published in peer-reviewed journals including Transportation Research Part C: Emerging Technologies, IEEE Transactions on Intelligent Transportation Systems Ocean Engineering and so on. Her current research interests include autonomous vessels, cooperative control of multi-agent systems, model predictive control, and their application in waterborne transport systems.

About the author

Prof. ir. Hans(J.J.) Hopman is full professor “Ship Design, Production & Operations” at the Department of Maritime and Transport Technology, Delft University of Technology, Delft, The Netherlands.

His research interests include design, engineering, production, repair and operation of ships and other floating marine objects including their machinery and electric equipment. This also includes research on supporting topics like logistics, finance, marketing, sustainability and shipping management.

About the author

Prof. dr. Rudy R. Negenborn is full professor in Multi-Machine Operations & Logistics. He is head of the Section Transport Engineering & Logistics of Department Maritime & Transport Technology. His research interests include intelligent infrastructures & logistics, automatic control and coordination of transport technology (including smart vessels) in general, whereby he proposes multi-agent system and model predictive control approaches that benefit from real-time information availability and the potential of communication. As such, his research anticipates the massive introduction of sensing, computation, and communication technologies. This is materialized into innovative solutions for smart equipment, transport hubs, ports and (synchro modal) networks.

Prof. Negenborn has over 200 peer reviewed academic publications. He leads NWO, EU and industry funded research, and is on the editorial board of the series on “Intelligent Systems, Control and Automation: Science and Engineering”.

He was moreover general chair of the 6th International Conference on Computational Logistics, has acted as member of the organizing committee of several other international conferences (including IEEE control conferences and maritime systems & logistics conferences) and was guest editor of special journal issues on autonomous vessels and computational logistics. In addition, he is the editor of the books “Intelligent Infrastructures”, “Distributed Model Predictive Control Made Easy”, and “Transport of Water versus Transport over Water”.

Reference

Linying Chen, Hans Hopman, Rudy R. Negenborn. Distributed Model Predictive Control for cooperative floating object transport with multi-vessel systems. Ocean Engineering, volume 191 (2019) 106515.

Go To Ocean Engineering

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