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An augmented version of the traditional relay feedback experiment is proposed. It aims at producing an input with energy concentrated to a frequency band, corresponding to a certain phase sector of the Nyquist curve of the process to be identified. A non-convex problem is formulated. Sub-optimal, but efficient, algorithms are developed.
Today, the majority of control applications in embedded systems, e.g., in the automotive domain, are implemented as software tasks on shared platforms. Ignoring implementation impacts during the design of embedded control systems results in complex timing behaviors that may lead to poor performance and, in the worst case, instability of control applications. This article presents a methodology for
The European Spallation Source will, once fully operational in 2025, be the world's brightest neutron source. The neutrons will be generated by bombarding a tungsten target with protons accelerated to 96\% the speed of light by electromagnetic fields confined in 155 radio-frequency cavities along the world's most powerful linear accelerator.This thesis has been motivated by the strict control spec
The goal of this work is to explore ways of generating state trajectories for dynamical systems subject to computational constraints, obstacles and priority assignment. The algorithms are developed for a miniature unmanned aerial vehicle (UAV) in a modular fashion and include (1) a genetic algorithm (GA) for solving the traveling salesman problem (TSP) with respect to priorities and obstacle avoid
Reference Attribute Grammars (RAGs) is a declarative executable formalism used for constructing compilers and related tools. Existing implementations support concurrent evaluation only with global evaluation locks. This may lead to long latencies in interactive tools, where interactive and background threads query attributes concurrently.We present lock-free algorithms for concurrent attribute eva
As our society becomes more and more dependent on IT systems, failures of these systems can harm more and more people and organizations. Diligently performing risk and hazard analysis helps to minimize the potential harm of IT system failures on the society and increases the probability of their undisturbed operation. Risk and hazard analysis is an important activity for the development and operat
An implementation of the spectral estimation method presented in Bagge Carlson et al. "Linear Parameter-Varying Spectral Decomposition." 2017 American Control Conference.
Provides implementations of Ijspeert et al. 2013 and of Martin Karlsson, Fredrik Bagge Carlson, et al. 2017
A Julia toolbox for approximation of functions using basis function expansions (BFEs).BFEs are useful when one wants to estimate an arbitrary/unknown/complicated functional relationship between (in the simple case) two variables, y and v. In simple linear regression, we might consider a functional relationship y = ϕ(v) = αv + β, with parameters α and β. However, if the function ϕ has an arbitrary
Solves the same problem as iLQG, with an added constraint on the KL-divergence between the new trajectory distribution and the distribution induced by a previous controller. This feature can be used in an outer loop with repeated experiments between the iterations if the model used for optimization is uncertain.
This toolbox works similar to that of other major computer-aided control systems design (CACSD) toolboxes. Systems can be created in either a transfer function or a state space representation. These systems can then be combined into larger architectures, simulated in both time and frequency domain, and analyzed for stability/performance properties.
In this paper, a compact pattern reconfigurable dual-antenna array is designed at 2.65 GHz for MIMO terminal applications, such as laptops. Each antenna is composed of two layers, i.e., the monopole layer and the PIFA layer. By switching the PIN diodes on each layer, its radiation patterns can be varied between conical and boresight patterns. Two such identical antennas are placed side by side on
In order to reduce nitrogen oxides (NOx) and soot emissions while maintaining high thermal efficiency, more advanced combustion concepts have been developed over the years, such as Homogeneous Charge Compression Ignition (HCCI) and Partially Premixed Combustion (PPC), as possible combustion processes in commercial engines. Compared to HCCI, PPC has advantages of lower unburned hydrocarbon (UHC) an
Future district heating systems (so called 4th Generation District Heating (4GDH) systems) have to address challenges such as integration of (de)centralized renewable energy sources and storage, low system temperatures and high fluctuation of the supply temperature. This paper presents a novel framework for representing and simplifying on-grid energy systems as well as for dynamic thermo-hydraulic
In conventional seismic surveys, there is a waiting time between sequentially fired shots. This time is determined such that the deepest reflection of interest is recorded before the following source is fired. In a survey with simultaneous or blended sources, the waiting time between the firing of shots is not dependent on the deepest reflection of interest, it is usually much shorter and/or can h
An algorithm for high-performance path tracking for robot manipulators in the presence of model uncertainties and actuator constraints is presented. The path to be tracked is assumed given, and the nominal trajectories are computed using, for example, well-known algorithms for time-optimal path tracking. For online path tracking, the nominal, feedforward trajectories are combined with feedback in
Several aspects describing the state of the atmosphere in the North Sea region are considered in this chapter. These include large-scale circulation, means and extremes in temperature and precipitation, cyclones and winds, and radiation and clouds. The climate projections reveal several pronounced future changes in the state of the atmosphere in the North Sea region, both in the free atmosphere an
Background. The effects of different practices on fault distributions in evolving complex software systems is not fully understood. Software reuse and unit verification are prac- tices used to improve system reliability by minimising the number of late faults. Reused software benefits from already being verified while unit verification aims to find faults early.Aims. We want to study effects of so
