# Seminars at NTNU AMOS in 2013

### Guest lecture by Dr Francesco Di Corato, University of Pisa, on a unified framework for constrained visual-inertial navigation

15 November 2013 at 10:15-11:00

Room B343, Gløshaugen, Elektro Bld. D

The presentation will focus on loosely-coupled fusion of visual and inertial data for autonomous navigation.

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# Guest lecture by Dr Francesco Di Corato, University of Pisa, on a unified framework for constrained visual-inertial navigation

15 November 2013 at 10:15-11:00

Room B343, Gløshaugen, Elektro Bld. D

The presentation will focus on loosely-coupled fusion of visual and inertial data for autonomous navigation.

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### Abstract

Inertial navigation suffers from drifts due to several factors, in particular inertial sensor measurement errors. A viable alternative to classical aiding sensors used for Aided Inertial Navigation (integration with GPS, air data sensors, velocity loggers, …) is the adoption of a vision system that estimates the motion of the camera given a stream of successive images and image features tracked over time. Navigation via fusion of visual and inertial data is perhaps the most straightforward inspired-by-Nature approach, having direct evidences in daily living.

The presentation will be focused on the loosely-coupled fusion of visual and inertial data for autonomous navigation, by using visual measurements in the form of implicit constraints. A brief overview of the general problem of visual-inertial navigation will be given, together with a review of the most relevant approaches in the literature. The following discussion will largely concentrate on constrained visual-inertial navigation: in particular the convergence properties of the estimation, some implementation and robustness issues, the constrained optimal estimation schemes for the fusion of the inertial measurements with the visual measurements will be covered. The results presented will be supported with simulative and experimental results.

It is assumed that the audience has a background in mathematics, with some concepts of continuous/discrete-time dynamical systems, reference systems transformation and few notions of stochastic processes and optimal filtering (The discussion will be concentrated on the use of the Constrained Kalman Filter).

### About the Speaker

Dr Francesco Di Corato received the Master of Science degree with honors in Automation Engineering at University of Pisa in October, 2008. In June, 2103 he received the PhD in Automation, Robotics and Bioengineering from the University of Pisa, with a Dissertation titled: "A Unified Framework for Constrained Visual-Inertial Navigation with Guaranteed Convergence". The PhD Thesis concerned the use of visual constraints to the problem of aided inertial navigation in unstructured dynamic environments and the probabilistic vision-based robust pose estimation of bodies with known geometry. He is currently working at University of Pisa as research assistant on Guidance, Navigation and Control of high performance underwater vehicles.

His research interests mainly concern aided inertial navigation, robust Bayesian filtering, the adoption of Computer Vision for the interpretation of the environment, Guidance, Navigation and Control of underwater vehicles and Entropy-based exploration. During his research activity, he was enrolled in National and International projects, mainly in the framework of guidance, navigation and control of autonomous vehicles. In the period January-July 2011 he was Visiting Scholar at Vision Lab – University of California, Los Angeles, under the supervision of prof. Stefano Soatto.

### Guest lecture by Dr Rune Storvold, NORUT, on NORUT's technical and operational experience with UAV's for remote sensing

15 October 2013 at 13:15-15:00

Room B343, Gløshaugen, Elektro Bld. D

About the speaker

# Guest lecture by Dr Rune Storvold, NORUT, on NORUT's technical and operational experience with UAV's for remote sensing

15 October 2013 at 13:15-15:00

Room B343, Gløshaugen, Elektro Bld. D

About the speaker

### About the speaker

1991: Cand. Mag, University of Bergen.

1993: Cand. Scient. University of Bergen.

2001: Ph.D. University of Alaska Fairbanks.

Ph.D. thesis: Stratospheric ozone depletion and spectroscopic trace gas measurements

### Research topics

Arctic cloud, aerosol, and radiation interaction, and retrieval of cloud and surface properties from ground-based and space-born sensors. Parameterization of Arctic clouds and surface properties in GCM models. High latitude stratospheric ozone chemistry and retrieval of trace gases using optical spectroscopy.

### Seminar on hybrid dynamical systems by professor Andrew R. Teel, UCSB

9-20 September 2013

As part of the PhD course MR8500: Advanced Topics in Marine Control Systems, Professor Teel will give a 2-week intensive seminar on Hybrid Dynamical Systems.

# Seminar on hybrid dynamical systems by professor Andrew R. Teel, UCSB

9-20 September 2013

As part of the PhD course MR8500: Advanced Topics in Marine Control Systems, Professor Teel will give a 2-week intensive seminar on Hybrid Dynamical Systems.

AMOS is proud to announce the visit of Professor Andrew R. Teel, University of California at Santa Barbara in fall 2013.

**Course Outline**

**Examples of hybrid systems**

Hybrid automata, mechanical systems with impacts, hybrid control systems; Text Chapter 1**The solution concept**

Data, hybrid time domains, basic properties of solutions; Text Chapter 2.**Asymptotic stability**

Definitions, Lyapunov functions, equivalent characterizations, the invariance principle;

Text,Chapters 3, 7 & 8. Matrosov functions; Supplemental papers**Well-posed hybrid systems**

Basic assumptions, material from set-valued analysis, robustness; Text, chapters 4-6.**Consequences of robustness**

Linearizations; Text, Chapter 9. Simulation theory, averaging, singular perturbations; Supplemental papers.

**Prerequisites**

Exposure to stability theory for nonlinear systems,

E.g., Nonlinear Systems, 3rd ed., Hassan Khalil, Prentice-Hall

**Course summary**

Based on the book "Hybrid Dynamical Systems", by R. Goebel, R.G. Sanfelice, and A.R. Teel, Princeton University Press, 2012.The course covers modeling and stability theory for hybrid dynamical systems. The stability analysis tools are applied to prove closed-loop stability for control systems that employ hybrid feedback algorithms. The goal is to equip the student with state-of-the-art analysis and synthesis techniques for hybrid feedback systems. In order to follow the material in the course, it is helpful to have taken courses on linear systems (from a state-space point of view) and nonlinear systems (from a book like Hassan Khalil's "Nonlinear Systems"), and to be comfortable with the mathematics used in those courses.

The course starts with examples of hybrid systems. Next we rigorously define the solution concept, with a focus on hybrid time domains. Zeno solutions are discussed, as well as solutions that satisfy dwell-time or average dwell-time constraints. Then we begin to study asymptotic stability, including asymptotic stability of closed sets, which is a generalization that is important for hybrid systems. Lyapunov-based methods are emphasized. Subsequently, we address basic regularity conditions on the data of a hybrid system. These conditions generalize continuity of the right-hand side of a differential equation. They guarantee that the hybrid system is "well posed", in the sense that small perturbations to the data do not change the nature of the possible solutions. Set-valued analysis techniques are introduced to characterize this well-posedness property. Next we revisit asymptotic stability for well-posed hybrid systems and give several equivalent characterizations, including converse Lyapunov theorems. Subsequently, we develop stability analysis tools based on the invariance principle for hybrid systems. Time permitting, we also discuss averaging theory, singular perturbation theory, and input-to-state stability for hybrid systems. If there is time and interest, stochastic hybrid systems will also be discussed.

**About the lecturer**

Andrew R. Teel received his A.B. degree in Engineering Sciences from Dartmouth College in Hanover, New Hampshire, in 1987, and his M.S. and Ph.D. degrees in Electrical Engineering from the University of California, Berkeley, in 1989 and 1992, respectively. After receiving his Ph.D., he was a postdoctoral fellow at the Ecole des Mines de Paris in Fontainebleau, France. In 1992 he joined the faculty of the Electrical Engineering Department at the University of Minnesota, where he was an assistant professor until 1997. Subsequently, he joined the faculty of the Electrical and Computer Engineering Department at the University of California, Santa Barbara, where he is currently a professor. His research interests are in nonlinear and hybrid dynamical systems, with a focus on stability analysis and control design. He has received NSF Research Initiation and CAREER Awards, the 1998 IEEE Leon K. Kirchmayer Prize Paper Award, the 1998 George S. Axelby Outstanding Paper Award, and was the recipient of the first SIAM Control and Systems Theory Prize in 1998. He was the recipient of the 1999 Donald P. Eckman Award and the 2001 O. Hugo Schuck Best Paper Award, both given by the American Automatic Control Council, and also received the 2010 IEE Control Systems Magazine Outstanding Paper Award. He is an area editor for Automatica, and a Fellow of the IEEE and of IFAC.

### Guest lecture by professor Andrew R. Teel, UCSB, on stochastic hybrid systems with an application to global almost sure synchronization of planar orientation

9 September 2013 at 13:45-14:45

Room B343, Gløshaugen, Elektro Bld. D

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# Guest lecture by professor Andrew R. Teel, UCSB, on stochastic hybrid systems with an application to global almost sure synchronization of planar orientation

9 September 2013 at 13:45-14:45

Room B343, Gløshaugen, Elektro Bld. D

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### Abstract

The variables of a hybrid dynamical system can change both continuously and discontinuously. The type of change that occurs is dictated by where the variables are in the state space. Many new results on the analysis and synthesis of hybrid control systems have been developed over the last decade. Our latest research focuses on extending these results to a class of stochastic hybrid systems. In particular, we analyze the situation where the value to which the state jumps is affected by a random variable. In this talk, we describe this class of systems, provide some basic analysis tools for them, and discuss one particular motivation for this class of systems. The motivation is the problem of global almost sure synchronization of planar orientation. For planar orientation, the literature contains solutions to the problem of (sure) almost global synchronization, but not to the problem of global, almost sure synchronization. In this talk, we emphasize the distinction between these two problems, provide a solution to the latter problem, and highlight the preferred robustness properties of this solution.

### About the lecturer

Andrew R. Teel received his A.B. degree in Engineering Sciences from Dartmouth College in Hanover, New Hampshire, in 1987, and his M.S. and Ph.D. degrees in Electrical Engineering from the University of California, Berkeley, in 1989 and 1992, respectively. After receiving his Ph.D., he was a postdoctoral fellow at the Ecole des Mines de Paris in Fontainebleau, France. In 1992 he joined the faculty of the Electrical Engineering Department at the University of Minnesota, where he was an assistant professor until 1997. Subsequently, he joined the faculty of the Electrical and Computer Engineering Department at the University of California, Santa Barbara, where he is currently a professor. His research interests are in nonlinear and hybrid dynamical systems, with a focus on stability analysis and control design. He has received NSF Research Initiation and CAREER Awards, the 1998 IEEE Leon K. Kirchmayer Prize Paper Award, the 1998 George S. Axelby Outstanding Paper Award, and was the recipient of the first SIAM Control and Systems Theory Prize in 1998. He was the recipient of the 1999 Donald P. Eckman Award and the 2001 O. Hugo Schuck Best Paper Award, both given by the American Automatic Control Council, and also received the 2010 IEE Control Systems Magazine Outstanding Paper Award. He is an area editor for Automatica, and a Fellow of the IEEE and of IFAC.

He is visiting AMOS and NTNU to give the course "Hybrid Dynamical Systems" based on the book with the same title by R. Goebel, R. G. Sanfelice, and A. R. Teel, Princeton University Press, 2012.

### Workshop on applications of autonomy in the marine industry

Friday 30th August 2013.

Preliminary program

# Workshop on applications of autonomy in the marine industry

Friday 30th August 2013.

Preliminary program

Arranged in cooperation by the MUNIN project; www.unmanned-ship.org, the SEATONOMY project at SINTEF and AMOS.

### Guest lecture by Dr Phil McGillivary, US Coast Guard, on marine and arctic challenges with AUV, UAV and other technologies

10 June 2013 at 1:15-2:00 PM

Room B343, Gløshaugen, Elektro Bld. D

# Guest lecture by Dr Phil McGillivary, US Coast Guard, on marine and arctic challenges with AUV, UAV and other technologies

10 June 2013 at 1:15-2:00 PM

Room B343, Gløshaugen, Elektro Bld. D

The lecture will concentrate on experiences with unmanned aerial and underwater vehicles and related technologies in order to meet marine and arctic challenges such as climate research, environmental monitoring, surveillance, safety and security.

Dr. McGillivary has his PhD in Ecology from the University of Georgia, Athens, and is currently the Science Liaison for the US Coast Guard for the Pacific, and have been running science operations for the US icebreakers for the past 17 years.

### Guest lecture on autonomous control systems for UAV by Professor Maruthi R. Akella, University of Texas, Austin

12 March 2013 1:15-2:00 PM

Room B343, Gløshaugen, Elektro Bld. D

# Guest lecture on autonomous control systems for UAV by Professor Maruthi R. Akella, University of Texas, Austin

12 March 2013 1:15-2:00 PM

Room B343, Gløshaugen, Elektro Bld. D

Professor Maruthi R. Akella

Aerospace Engineering and Engineering Mechanics Controls Lab for Distributed and Uncertain Systems, The University of Texas at Austin, USA.

URL: http://cdus.ae.utexas.edu

**Abstract**

A large number of emerging aerospace engineering applications are addressing the development of autonomous control systems with agile maneuvering and robust perception inside dynamic, complex and uncertain environments well beyond the limits of what is currently feasible. In this seminar, we present an overview of some recent advances in nonlinear stability theory and robust adaptive control. In particular, we discuss new and extremely powerful mathematical tools – Lyapunov Strictification and Filter Embedment – for dynamical systems that are subject to non-affine uncertainty characterizations and nonlinear parameterization constraints within the overall control architecture. Historically, it is well known that these control problems are extremely difficult to solve resulting in the unfortunate and wide-spread adoption of Procrustean schemes. By taking the new strictification and embedment approaches, we can identify large classes of aero-mechanical systems that result in stable closed-loop designs together with performance guarantees and thus, can be efficiently solved. The seminar concludes with a brief discussion of space systems applications that include rapid responsive space situational awareness, closed-loop guidance for asteroid rendezvous missions, on-orbit tunable controllers for spacecraft attitude dynamics, and UAV enabled coordinated target pursuit.

**Speaker Bio**

Maruthi R. Akella currently holds the rank of Associate Professor with tenure and directs the Controls Lab for Distributed and Uncertain Systems (C-DUS) in the Department of Aerospace Engineering and Engineering Mechanics at the University of Texas at Austin. He received his PhD in Aerospace Engineering in 1998 from Texas A&M University and prior to joining the UT Austin faculty, he was a postdoctoral fellow with the Yale University Center for Systems Science. Dr. Akella's research program encompasses control theoretic investigations of nonlinear and coordinated systems, vision-based sensing for state estimation, and development of integrated human and autonomous multivehicle systems. He currently serves as Associate Editor for the Journal of Guidance, Control, and Dynamics (JGCD) and the IEEE Transactions on Aerospace and Electronic Systems (T-AES). Dr. Akella is an Associate Fellow of the American Institute of Aeronautics and Astronautics.

Annika Bremvåg