Now showing items 1-10 of 12
Regression analysis using a blending type spline construction
(Peer reviewed; Chapter; Bokkapittel, 2017-10-18)
Regression analysis allows us to track the dynamics of change in measured data and to investigate their properties. A sufficiently good model allows us to predict the behavior of dependent variables with higher accuracy, and to propose a more precise data generation hypothesis. By using polynomial approximation for big data sets with complex dependencies we get piecewise smooth functions. One way ...
Thyristor based short circuit current injection in isolated grids
(Peer reviewed; Chapter; Bokkapittel, 2017-02-16)
This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments.
Quaternion guidance and control of quadrotor
(Peer reviewed; Konferansebidrag; Bokkapittel; Conference object; Chapter, 2017-07-27)
This paper addresses the problem of trajectory tracking for underactuated quadrotors. A quaternion based guidance law is proposed which feeds into an attitude control system based on a PD+ control law. The desired attitude from the guidance law is defined such that the attitude control system tries to align the position error along the axis of the translational actuator. Simulation results are ...
Path-following in three dimensions using quaternions for a fixed-wing UAV
(Peer reviewed; Konferansebidrag; Bokkapittel; Conference object; Chapter, 2017-08-08)
This paper presents a three dimensional guidance strategy for fixed-wing UAVs using quaternions. The algorithm is based on constructing two quaternions, one which makes the UAV fly towards the path and one that makes the UAV follow the path. These two quaternions are then blended together such that the path-following objective is reached. The guidance algorithm is applied to a simple kinematic model ...
Approaches to learning of linear algebra among engineering students
(Peer reviewed; Bok; Book; Bokkapittel; Chapter, 2017-02)
The present paper investigates engineering students` own descriptions of what they mean by learning of linear algebra and how they know that they have learned something. I seek to extract keywords from engineering students` descriptions of learning of this discipline by drawing on grounded theory techniques and classifying the answers in conceptual and procedural approaches. By this, both detailed ...
Attitude Determination and Control System for Satellites in Elliptical Orbits - a Complete Solution
(Peer reviewed; Conference object; Konferansebidrag; Bokkapittel; Chapter, 2017-08-08)
This paper presents a complete solution to the problem of attitude determination and control for satellites in elliptical orbits. Specifically, it shows how to create the orbital mechanics, account for perturbing gravity torques, create a nonlinear PD+ attitude controller, map the control signal to desired thrust firings, implement magnetic field and Sun vector models, and how to implement a Madgwick ...
Autonomous Inspection of the International Space Station
(Peer reviewed; Konferansebidrag; Conference object; Bokkapittel; Chapter, 2017-09-18)
This paper presents a solution to autonomous inspection of the international space station using a rigid spacecraft. Specifically, the paper presents the orbital mechanics, formation dynamics as well as rotational dynamics required to control the spacecraft relative to the space station, and then presents two PD+ controllers enabling a spacecraft to track a series of waypoints while pointing a sensor ...
Pre-evaluation and interactive editing of B-spline and GERBS curves and surfaces
(Peer reviewed; Konferansebidrag; Conference object; Bokkapittel; Chapter, 2017-12)
Interactive computer based geometry editing is very useful for designers and artists. Our goal has been to develop useful tools for geometry editing in a way that increases the ability for creative design. When we interactively editing geometry, we want to see the change happening gradually and smoothly on the screen. Pre-evaluation is a tool for increasing the speed of the graphics when doing ...
Exploring Tensions in a Mathematical Course for Engineers utilizing a Flipped Classroom Approach
(Book; Chapter; Bok; Bokkapittel; Peer reviewed, 2017-02)
Flipped Classroom approaches to teaching are becoming increasingly popular in higher education, but there is a lack of empirical research. We present here a study performed during an engineering course for 20 students at a Norwegian university, on student appropriation towards Flipped Classroom through interviews, questionnaire, video/quiz usage statistics and classroom filming. We approach this ...
Solution of Pure Scattering Radiation Transport Equation (RTE) Using Finite Difference Method (FDM)
(Peer reviewed; Book; Bok; Bokkapittel; Chapter, 2017-05-19)
Radiative transfer is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering. Radiative Transfer Equation (RTE) have been applied in a many subjects including optics, astrophysics, atmospheric science, remote sensing, etc. Analytic solutions for RTE exist for simple cases, ...