News

Defense Zaki Almuzakki:"Practical stabilization of systems with countable set of actions. A nearest action selection approach"

11 March 2024 at 09.00 a.m.

Location: Aula Academy Building, Broerstraat 5 Groningen

Promotor: Prof Bayu Jayawardhana and Prof Antonis Vakis

The control and stabilization of systems, whose inputs can only take values from finite countable sets, is studied and analyzed in this thesis. Such systems arise in a number of engineering systems, including a renewable energy storage system that is modeled and presented in the latter part of the thesis. In the first part of the thesis, a simple input-quantization method based on the nearest action selection approach, namely the nearest action control (NAC), is proposed and analyzed. The proposed control methods are applied to both single- and multi-agent systems, with a particular focus on the class of passive nonlinear systems. Practical stability analysis is shown for both classes of systems where the convergence region can be related to the property of the countable input sets. A strategy to achieve exponential convergence rate is also presented by expanding the input sets in a logarithmic fashion. In the second part of this thesis, the modeling of the ocean grazer wave energy converter (OG-WEC) system in the port-Hamiltonian framework is given. The model contains the hydrodynamic interaction among the floating bodies of OG-WEC via Cummin's equation and the mechanical prime-mover systems of OG-WEC. The developed multi-domain model using port-Hamiltonian systems is validated using existing numerical models of OG-WEC systems.

Major project to improve remote-controlled vehicles

05 February 2024

Professor Ming Cao from the Engineering and Technology Institute Groningen (ENTEG) is the leading partner in an NWO-funded project to improve the quality and safety of remotely operated vehicles in offshore operations. Prof. Elbert de Jong from the University of Utrecht is the main co-applicant. The total NWO-KIC grant amounts to EUR 1.3 million.

The project will be co-financed by industrial partners Fugro Innovation & Technology and Damen. Other universities involved are Eindhoven University of Technology, VU University Amsterdam and Delft University of Technology.

Algorithms for more control

With his team, Prof. Cao focuses on the design of robust and self-sufficient autonomous control of offshore vehicles and constructing algorithms that guarantee control in scenarios with limited or no communication. Partners from other universities will work on better assessing the impact of autonomous offshore operations and developing a safe legislative framework for such operations.

Teaming of man and machine

Operations may include fishing, exploration and transportation. And also increasingly, engineering and construction for infrastructure around energy transition such as offshore wind farm development. Cao explains that the ultimate goal is human-in-the-loop control: "With Human-in-the-Loop you achieve what neither a human nor a machine alone can achieve. When a machine is unable to solve a problem, humans must intervene. When errors in communication are detected, for example, the control algorithms to be developed will create the ‘brain’ that allows vehicles to switch between human operator(supervisor) and autonomous control. The project therefore ultimately enhances Dutch offshore workers' teaming with (semi-)autonomous marine vessels.”

NWO KIC funding

NWO develops innovation programmes in the Knowledge and Innovation Covenant (KIC) focused on the societal challenges of the Netherlands to realise impact for the economy, people and society. The emphasis is on collaboration between knowledge institutions, private parties and government. Through the KIC programme, NWO contributes to the government's mission-driven top sectors and innovation policy. This grant has been awarded in the programme 'Collaboration between humans and (semi-)autonomous systems'.

Prof Michele Cucuzzella new Associate Professor DTPA per 1 February 2024

Michele Cucuzzella started as an associate professor in ENTEG (DTPA-group).
More information about him and his research profile is at https://www.rug.nl/research/enteg/news/introducing-our-new-staff-scientific-member-michele-cucuzzella

Defense Tinghua Li: "Motion control for nonholonomic unicycle robots"

30 January 2024 at 2.30 p.m.

With the rapid development of perception, communication and computation technologies and the increasing requirements on safety-critical systems, autonomous robots must be able to safely achieve missions in a hazardous environment and to cope with difficult situations. Such safety-critical tasks require smart motion control strategies to address complex constraints and to navigate in cluttered scenarios. However, the motion control for nonholonomic wheeled mobile robots is challenging as they are subject to the kinematic constraint which limits sideway movements. This restriction makes traditional control methods insufficient for precise motions, and it poses challenges in navigating cluttered environment safely.

This doctoral research focuses on developing algorithms for nonholonomic robots in an unknown cluttered scenario, where the robot solely relies on the limited onboard sensory measurements for exploration. Part I aims to bridge the gap between perception and control tasks, by introducing the projected gradient-ascent source-seeking control and safety guarantee for a single robot traversing an unknown signal field where random obstacles exist. The main contributions lie in the control design with asymptotic convergence analysis and the CBF design with uniform relative degree. The results are extended to the multi-agent system in Part II, where a distributed CBF-QP framework is proposed for achieving collision avoidance and maintaining connectivity preservation in flocking cohesion control problem, and an adaptive spacing policy is presented for flexible coordination. In summary, this doctoral thesis contributes to novel (distributed) control algorithms for nonholonomic robots that warrant four control systems properties: safety guarantee, configuration stabilization, optimization feasibility, and group behavior flexibility.

Defense Hao Yin: "Contraction analysis of nonlinear systems and its application"

8 January 2024 at 9 a.m.

Where: Aula Academy Building

Promotors: Prof Bayu Jayawardhana, Prof Stephan Trenn

Abstract: The thesis addresses various issues concerning the convergence properties of switched systems and differential algebraic equation (DAE) systems. Specifically, we focus on contraction analysis problems, as well as tackling problems related to stabilization and synchronization.
We consider the contraction analysis of switched systems and DAE systems. To address this, a transformation is employed to convert the contraction analysis problem into a stabilization analysis problem. This transformation involves the introduction of virtual systems, which exhibit a strong connection with the Jacobian matrix of the vector field. Analyzing these systems poses a significant challenge due to the distinctive structure of their Jacobian matrices. Regarding the switched systems, a time-dependent switching law is established to guarantee uniform global exponential stability (UGES). As for the DAE system, we begin by embedding it into an ODE system. Subsequently, the UGES property is ensured by analyzing its matrix measure. As our first application, we utilize our approach to stabilize time-invariant switched systems and time-invariant DAE systems, respectively. This involves designing control laws to achieve system contractivity, thereby ensuring that the trajectory set encompasses the equilibrium point. In our second application, we propose the design of a time-varying observer by treating the system’s output as an algebraic equation of the DAE system.
In our study on synchronization problems, we investigate two types of synchronization issues: the trajectory tracking of switched oscillators and the pinning state synchronization. In the case of switched oscillators, we devise a time-dependent switching law to ensure that these oscillators effectively follow the trajectory of a time-varying system. As for the pinning synchronization problem, we define solvable conditions and, building upon these conditions, we utilize contraction theory to design dynamic controllers that guarantee synchronization is achieved among the agents.

UG professor Jayawardhana appointed scientific director DISC

29 November 2023

Bayu Jayawardhana is appointed as of 1 January 2024 as scientific director of DISC, the interuniversity research institute and graduate school that unites all university groups in the Netherlands that are active in systems and control theory and engineering. The University of Groningen (UG) participates in DISC , the Dutch Institute of Systems and Control, with the technical universities of Delft and Eindhoven, and Twente University.

Jayawardhana is professor at the Engineering and Technology Institute Groningen (Faculty of Science and Engineering, RUG). DISC also offers a nationally organized graduate programme for PhD students in this field. DISC is one of three major graduate schools in mechanical engineering in the Netherlands.

Engineering in Groningen

Jayawardhana is professor of Mechatronics and Nonlinear Control Engineering. Recently, Jayawardhana was also appointed fellow of the Netherlands Academy of Engineering (NAE). The appointment of Jayawardhana at DISC reflects once again the technical profile of the UG.

DISC since 2017

In 2017 the four technical universities in the Netherlands and the University of Groningen signed a collective agreement in which they express their support for DISC. DISC is the formal successor of the Dutch Network of Systems and Control, which offered a national graduate program in systems and control since 1987.

Heeres, Jayawardhana and Scherpen appointed NAE Fellow

09 November 2023

ENTEG members Prof. Erik Heeres , Prof. Bayu Jayawardhana and Prof. Jacquelien Scherpen have been appointed as fellows of the Netherlands Academy of Engineering (NAE). This prestigious recognition is a testament to their contributions to engineering sciences and applied research and innovation.

The Netherlands Academy of Engineering

The NAE unites the top experts active in technological sciences and applied research and development. They come from scientific, governmental, and industrial organizations, and share the passion for engineering-based innovation as a means to overcome many of our societal challenges, and to sustain our country’s earning power within the European and international context.

The purpose of the NAE is to foster a vibrant and effective climate of responsible, inclusive, and impactful engineering-based innovation, rooted in a world-class knowledge and talent base in technological sciences and human centric design. It also strives to make the voice of engineering better heard among key decision makers. It will do so by offering a forum for constructive debate, by orchestrating the pivot to action, and by providing advice on urgent strategic challenges and necessary improvements to the Dutch knowledge and innovation system.

Jacquelien Scherpen to be the New Rector Magnificus of the University of Groningen

03 July 2023

The University of Groningen's Supervisory Board has appointed Prof. J.M.A. (Jacquelien) Scherpen, professor in Discrete Technology and Production Automation at the Engineering and Technology Institute Groningen (ENTEG), as the new Rector Magnificus and member of the Board of the University of Groningen. The appointment will cover a period of four years, starting on September 1, 2023. Jacquelien Scherpen will succeed the current Rector Magnificus, Cisca Wijmenga.

Jacquelien Scherpen brings a wealth of experience and expertise to her new role. Throughout her academic journey, she has made significant contributions to the field of Engineering and Technology. Her remarkable career includes serving as the scientific director of ENTEG from 2013 to 2019, director of the Groningen Engineering Center since 2016, and currently holding the position of FSE Director of Engineering. She also serves as the Captain of Science for the Dutch top sector High Tech Systems and Materials (HTSM).

Jacquelien Scherpen's research achievements have earned her national and international recognition. She is a fellow of the IEEE and has been actively involved in the International Federation of Automatic Control (IFAC), currently serving as a member of the IFAC council. In 2019, she received a royal distinction as Knight in the Order of the Netherlands Lion. In 2023, she was awarded the Prince Friso prize for Engineer of the Year in the Netherlands.

While her appointment as Rector brings pride and excitement, Jacquelien's departure from her previous roles will undoubtedly be felt. Her expertise and presence within the ENTEG team have been invaluable, and she leaves behind a legacy of exceptional contributions. We extend our congratulations to Jacquelien Scherpen on this well-deserved appointment as the new Rector of the University of Groningen. We are confident that under her leadership, the university will continue to excel and reinforce its position as a leading institution of higher education.