<p>The WITAS project aims to develop technologies to enable an Unmanned Airial Vehicle (UAV) to operate autonomously and intelligently, in applications such as traffic surveillance and remote photogrammetry. Many of the necessary control and reasoning tasks, e.g. state estimation, reidentification, planning and diagnosis, involve prediction as an important component. Prediction relies on models, and such models can take a variety of forms. Model design involves many choices with many alternatives for each choice, and each alternative carries advantages and disadvantages that may be far from obvious. In spite of this, and of the important role of prediction in so many areas, the problem of predictive model design is rarely studied on its own.</p><p>In this thesis, we examine a range of applications involving prediction and try to extract a set of choices and alternatives for model design. As a case study, we then develop, evaluate and compare two different model designs for a specific prediction problem encountered in the WITAS UAV project. The problem is to predict the movements of a vehicle travelling in a traffic network. The main difficulty is that uncertainty in predictions is very high, du to two factors: predictions have to be made on a relatively large time scale, and we have very little information about the specific vehicle in question. To counter uncertainty, as much use as possible must be made of knowledge about traffic in general, which puts emphasis on the knowledge representation aspect of the predictive model design.</p><p>The two mode design we develop differ mainly in how they represent uncertainty: the first uses coarse, schema-based representation of likelihood, while the second, a Markov model, uses probability. Preliminary experiments indicate that the second design has better computational properties, but also some drawbacks: model construction is data intensive and the resulting models are somewhat opaque.</p> / Report code: LiU-Tek-Lic-2002:15.

<p>As long as there have been computers, one goal has been to be able to communicate with them using natural language. It has turned out to be very hard to implement a dialog system that performs as well as a human being in an unrestricted domain, hence most dialog systems today work in small, restricted domains where the permitted dialog is fully controlled by the system.</p><p>In this thesis we present two dialog systems for communicating with an autonomous agent:</p><p>The first system, the WITAS RDE, focuses on constructing a simple and failsafe dialog system including a graphical user interface with multimodality features, a dialog manager, a simulator, and development infrastructures that provides the services that are needed for the development, demonstration, and validation of the dialog system. The system has been tested during an actual flight connected to an unmanned aerial vehicle.</p><p>The second system, CEDERIC, is a successor of the dialog manager in the WITAS RDE. It is equipped with a built-in machine learning algorithm to be able to learn new phrases and dialogs over time using past experiences, hence the dialog is not necessarily fully controlled by the system. It also includes a discourse model to be able to keep track of the dialog history and topics, to resolve references and maintain subdialogs. CEDERIC has been evaluated through simulation tests and user tests with good results.</p> / Report code: LiU{Tek{Lic{2006:29.

<p>Modern krigföring genomförs till stor del i form av gemensamma operationer. Helikoptern är en relativt ny tillgång i modern krigföring men används i stor utsträckning för olika uppgifter. Helikopterns förmåga att flyga men ändå bibehålla en nära kontakt med markstyrkorna har gjort den unik, men det har även inneburit att den har varit svår att placera, luft eller mark, vilket i sin tur inneburit att teoriutvecklingen kring helikoptern gått långsamt. Uppsatsen skall beskriva ett tänkbart sätt att nyttja helikopterns förmågor i gemensamma operationer. Arbetet utförs i två steg där första steget görs för att generera en teori utifrån teorier om kombinerad bekämpning, gemensamma operationer och teorier om helikopterns förmågor. Därefter genomförs en fallstudie i syfte att undersöka i vilken utsträckning teorin kan anses vara prövbar i ett senare skede.</p> / <p>Modern warfare of today is to a large extent carried out as joint operations. The helicopter is a fairly new asset for modern warfare but is used frequently for different tasks. The helicopters ability to fly and yet remain in close contact with the ground forces makes it unique, but that is also one of the major reasons why it has been hard to lable the helicopter, air or ground, which in turn is why theory development regarding helicopters has been slow. This essay will attemp to describe a plausible way to use helikopters in joint operations. It will be done in two steps where the first step aims to generate a theory that derives from the theories behind combined arms warfare, joint operations and theories regarding the helicopter abilitys. The theory will be used in an exemplifying case study that aims to investigate to what extent the theory can be regarded as valid and subjected to a test.</p>

<p>Syftet med uppsatsen är att undersöka, jämföra och diskutera eventuella faktorer till varför det har skett en så kraftig ökning av helikopterhaverier under de senaste tio åren jämfört med stridsflygshaverier. Problemet belyses och analyseras utefter ett MTO- perspektiv (människa, teknik och organisation). Stor vikt i uppsatsen läggs på de haverirapporter som är en följd av haverier mellan 1997 – 2007. Organisationsförändringar, flygmaskiner och utbildning är exempel på några andra delar som också behandlas. Viktigaste slutsatserna med uppsatsen är att helikopterhaverierna till stor del berott på den mänskliga faktorn medan stridsflyget har haft mer varierande orsaker. Faktorer som kan ha påverkat så att helikopterhaverierna har ökat jämfört med stridsflygshaverierna är följande tre.- Sammanslagningen av armeflyget, marinflyget och helikopterverksamheten i Flygvapnet.- Att flygning med helikopter i större omfattning sker på låg höjd.- Fler personer i en besättning kan påverka flygningen.</p> / <p>The purpose of this essay is to investigate, compare and discuss possible factors that have contributedto the big increase in helicopter crashes in the last ten years compared to fighter jets. The problem is looked upon and analyzed from an HTO perspective (human, technology and organisation). A lot of the essay is focused on the investigation reports that has followed all crashes between 1997-2007. Organisational change, different aircrafts and education and training are examples of other factorsthat are discussed in the essay. The most important conclusions that have been drawn are that helicopter crashes are mostly due to human factors reasons. Fighter jet crashes have more variation in the causes. Factors that may have been contributing in increasing helicopter crashes compared to fighter jets are:- The fusion between the army, marine and air force helicopter units- Helicopter flying is more frequently done on a lower altitude- There are more people part of the helicopter crew which can affect the flight</p>

Syftet med uppsatsen är att undersöka, jämföra och diskutera eventuella faktorer till varför det har skett en så kraftig ökning av helikopterhaverier under de senaste tio åren jämfört med stridsflygshaverier. Problemet belyses och analyseras utefter ett MTO- perspektiv (människa, teknik och organisation). Stor vikt i uppsatsen läggs på de haverirapporter som är en följd av haverier mellan 1997 – 2007. Organisationsförändringar, flygmaskiner och utbildning är exempel på några andra delar som också behandlas. Viktigaste slutsatserna med uppsatsen är att helikopterhaverierna till stor del berott på den mänskliga faktorn medan stridsflyget har haft mer varierande orsaker. Faktorer som kan ha påverkat så att helikopterhaverierna har ökat jämfört med stridsflygshaverierna är följande tre.- Sammanslagningen av armeflyget, marinflyget och helikopterverksamheten i Flygvapnet.- Att flygning med helikopter i större omfattning sker på låg höjd.- Fler personer i en besättning kan påverka flygningen. / The purpose of this essay is to investigate, compare and discuss possible factors that have contributedto the big increase in helicopter crashes in the last ten years compared to fighter jets. The problem is looked upon and analyzed from an HTO perspective (human, technology and organisation). A lot of the essay is focused on the investigation reports that has followed all crashes between 1997-2007. Organisational change, different aircrafts and education and training are examples of other factorsthat are discussed in the essay. The most important conclusions that have been drawn are that helicopter crashes are mostly due to human factors reasons. Fighter jet crashes have more variation in the causes. Factors that may have been contributing in increasing helicopter crashes compared to fighter jets are:- The fusion between the army, marine and air force helicopter units- Helicopter flying is more frequently done on a lower altitude- There are more people part of the helicopter crew which can affect the flight

Modern krigföring genomförs till stor del i form av gemensamma operationer. Helikoptern är en relativt ny tillgång i modern krigföring men används i stor utsträckning för olika uppgifter. Helikopterns förmåga att flyga men ändå bibehålla en nära kontakt med markstyrkorna har gjort den unik, men det har även inneburit att den har varit svår att placera, luft eller mark, vilket i sin tur inneburit att teoriutvecklingen kring helikoptern gått långsamt. Uppsatsen skall beskriva ett tänkbart sätt att nyttja helikopterns förmågor i gemensamma operationer. Arbetet utförs i två steg där första steget görs för att generera en teori utifrån teorier om kombinerad bekämpning, gemensamma operationer och teorier om helikopterns förmågor. Därefter genomförs en fallstudie i syfte att undersöka i vilken utsträckning teorin kan anses vara prövbar i ett senare skede. / Modern warfare of today is to a large extent carried out as joint operations. The helicopter is a fairly new asset for modern warfare but is used frequently for different tasks. The helicopters ability to fly and yet remain in close contact with the ground forces makes it unique, but that is also one of the major reasons why it has been hard to lable the helicopter, air or ground, which in turn is why theory development regarding helicopters has been slow. This essay will attemp to describe a plausible way to use helikopters in joint operations. It will be done in two steps where the first step aims to generate a theory that derives from the theories behind combined arms warfare, joint operations and theories regarding the helicopter abilitys. The theory will be used in an exemplifying case study that aims to investigate to what extent the theory can be regarded as valid and subjected to a test.

The helicopter is a Multiple-Input Multiple-Output (MIMO) system with highly coupled characteristics, which increases the complexity of the system dynamics. In addition, the system dynamics of the helicopter are unstable, referring to its tendency to deviate from an equilibrium when disturbed. Despite the complexity in its modelling and control, the benefit of using a helicopter for unmanned, autonomous applications can be tremendous. One particular application that motivates this research is the use of an unmanned small-scale helicopter in an autonomous survey mission over an area struck by disaster, such as an earthquake. The work presented in this thesis provides a framework for utilizing a platform system for research and development of small-scale helicopter systems. A platform system enables testing and analysis to be performed indoor in a controlled environment. This can provide a more convenient mean for helicopter research since the system is not affected by environmental elements, such as wind, rain or snow condition. However, the presence of the platform linkages poses challenges for analysis and controller design as it alters the helicopter system flight dynamics. Through a six degree-of-freedom (6 DOF) platform model derived in this research, the criteria for matching the trim conditions between the platform system and a stand alone helicopter have been identified. With the matched trim conditions, linearization is applied to perform analysis on the effects that the platform has on the system dynamics. The results of the analysis provide insights into both the limitations and benefits of utilizing the platform system for helicopter research. Finally, a Virtual Joint Control scheme is proposed as an unified control strategy for both the platform and the stand alone helicopter systems. Having a consistent control scheme between the two systems allows for comparisons between simulation and experimental results for the two systems to be made more readily. Furthermore, the Virtual Joint Control scheme represents a novel flight control strategy for stand alone helicopter systems.

This thesis deals with the development of a Conceptual Design Tool for unmanned helicopters, so called VTOL UAVs. The goal of the Design Tool is: • Quick results • Good accuracy • Easy to use The two first points of the goal are actually more or less dependent on each other. In almost all cases a high accuracy gives a slow calculator and vice versa. In order to fulfill the goal a compromise between calculation accuracy and calculation time needs to be done. To make the Design Tool an easy to use program a graphical user interface is used. The graphical user interface allows the user to systematically work his way thru the program from a fictive mission to a complete design of a helicopter. The pre-requirements on the user have been eliminated to a minimum, but for the advanced user the possibilities to create more specific and complex helicopters are good. In order to develop a Conceptual Design Tool the entire helicopter needs to be seen as a complete system. To see the helicopter as a system all of the sub parts of a helicopter need to be studied. The sub parts will be compared against each other and some will be higher prioritized than other. The outline of this thesis is that it is possible to make a user friendly Conceptual Design Tool for VTOL UAVs. The design procedure in the Design Tool is relatively simple and the time from start to a complete concept is relatively short. It will also be shown that the calculation results have a good agreement with real world flight test data.

The market for vertical takeoff and landing unmanned aerial vehicles, VTOL UAVs, is growing rapidly. To reciprocate the demand of VTOL UAVs in offshore applications, CybAero has developed a novel concept for landing on moving objects called MALLS, Mobile Automatic Launch and Landing Station. MALLS can tilt its helipad and is supposed to align to either the horizontal plane with an operator adjusted offset or to the helicopter skids. Doing so, eliminates the gyroscopic forces otherwise induced in the rotordisc as the helicopter is forced to change attitude when the skids align to the ground during landing or when standing on a jolting boat with the rotor spun up. This master’s thesis project is an attempt to get the concept of MALLS closer to a quarter scale implementation. The main focus lies on the development of the measurement methods for achieving the references needed by MALLS, the hori- zontal plane and the plane of the helicopter skids. The control of MALLS is also discussed. The measurement methods developed have been proved by tested implementations or simulations. The theories behind them contain among other things signal filtering, Kalman filtering, sensor fusion and search algorithms. The project have led to that the MALLS prototype can align its helipad to the horizontal plane and that a method for measuring the relative attitude between the helipad and the helicopter skids have been developed. Also suggestions for future improvements are presented.

When a helicopter is flying, the dynamics vary depending on, for example, speed and position. Hence, a time-invariant linear model cannot describe its properties under all flight conditions. It is therefore desirable to update the linear helicopter model continuously during the flight. In this thesis, two different recursive estimation methods are presented, LMS (Least Mean Square) and adaptation with a Kalman filter. The main purpose of the system estimation is to get a model which can be used for feedback control. In this report, the estimated model will be used to create a LQ controller with the task of keeping the output signal as close to the reference signal as possible.Simulations in this report show that adaptive feedback control can be used to control a helicopter's angular velocities and that the possibility to use an adaptive control algorithm in a real future helicopter is good.