BEVs are a critical pathway towards achieving energy independence and meeting greenhouse and pollutant gas reduction goals in the current and future transportation sector [1]. Automotive manufacturers are increasingly investing in the refinement of electric vehicles as they are becoming an increasingly popular response to the global need for reduced transportation emissions. Therefore, there is a desire to extract the most fuel economy from a vehicle as possible. Some areas that manufacturers spend much effort on include minimizing the vehicle’s mass, body drag coefficient, and drag within the powertrain. When these values are defined or unchangeable, interest is driven to other areas such as investigating the control strategy of the powertrain. If two or more electric motors are present in an electric vehicle, Torque Vectoring (TV) strategies are an option to further increase the fuel economy of electric vehicles. Most of the torque vectoring strategies in literature focus exclusively on enhancing the vehicle stability and dynamics with few approaches that consider efficiency or energy consumption. The limited research on TV that addresses system efficiency have been done on a small number of vehicle architectures, such as four independent motors, and are distributing torque front/rear instead of left/right which would not induce any yaw moment. The proposed research aims to address these deficiencies in the current literature. First, by implementing an efficiency-optimized TV strategy for a rear-wheel drive, dual-motor vehicle under straight-line driving as would be experienced in during the EPA drive cycle tests. Second, by characterizing the yaw moment and implementing strategies to mitigate any undesired yaw motion. The application of the proposed research directly impacts dual-motor architectures in a way that improves overall efficiency which also drives an increase in fuel economy. Increased fuel economy increases the range of electric vehicles and reduces the energy demand from an electrical source that may be of non-renewable origin such as coal.

Clear changes occurred in the field of conventional arms control in the last two decades. States adopted a multitude of norms on especially small arms control in various multilateral control instruments. In addition, non-governmental advocacy actors often established themselves as active participants in control debates with governments. The changes are surprising because they took place in the security sphere and therewith in an area traditionally understood to be the exclusive domain of governments. This research project investigates the significance of the changes for the traditional understanding of security governance. Specifically, it investigates the emergence of control norms and the role and policy impact of non-governmental actors in the promotion of the norms. It asks whether the normative changes and significance of nongovernmental actors therein challenge the understanding of security governance that underpins many established approaches to international relations theory.

Sammanfattning  Examensarbete, Civilekonomprogrammet - Controller, Ekonomihögskolan vid Linnéuniversitetet i Växjö, vårterminen 2023.  Titel: Blir ett plus ett verkligen två?  En kvalitativ fallstudie om hur en privat organisation hanterar spänningar i styrningen efter företagsförvärv   Bakgrund & problem Företagsförvärv har blivit ett populärt tillvägagångssätt för att uppnå snabb och hög tillväxt. Trots detta har det visat sig att merparten av företagsförvärv leder till misslyckanden på grund av svårigheten med att integrera företagens strukturella samt kulturella och strategiska skillnader. För att kunna hantera dessa skillnader är det avgörande att utforma ett styrsystem som tar hänsyn till det förvärvande och förvärvade företagens styrning. Den befintliga forskningen har däremot inte belyst hur företag bör konstruera sin styrning efter ett genomfört företagsförvärv. Bristen på samverkan mellan de två företagen leder så småningom till interna konflikter, även benämnt styrspänningar.  Syftet Syftet med denna studie är att undersöka en organisations styrning både under och efter ett företagsförvärv. Särskilt uppmärksamhet har lagts på att identifiera och illustrera vilka styrspänningar som uppstår efter företagsförvärv samt att undersöka de underliggande orsakerna till deras uppkomst. Slutligen siktar undersökningen även på att finna och förklara hur dessa styrspänningar hanteras inom en privat organisation.  Metod Studien har undersökt en privat organisation som genomför företagsförvärv. Utgångspunkten för denna undersökning har varit genom en kvalitativ forskningsansats med semistrukturerade intervjuer, där en fallstudie med förklarande karaktär har tillämpats. Den empiriska insamlingen har inhämtats från både det förvärvande och förvärvade företagens anställda. Dessutom har interna dokument samt årsredovisningar använts för att komplettera studiens empiriska underlag. Slutsats Studien har identifierat fem styrspänningar som har uppstått efter genomförda företagsförvärv;“Makt till de anställda vs Formella strukturer”, “Gamla system vs Nya system”,“Gamla uppföljningsrutiner vs Nya uppföljningsrutiner”,“Gamla förmåner vs Nya förmåner”, “Gammal identitet vs Ny identitet”. Uppkomsten av dessa styrspänningar förklaras utifrån att det finns kontraster i det förvärvande och förvärvade företagets styrning. Dessutom beror det på att de förvärvade anställda hade förväntningar som inte uppfylldes efter förvärvet. Utöver det har institutionella logiker varit en annan bidragande faktor, där den ena logiken försvagar den andra. Hur dessa fem styrspänningar har hanterats beror på omständigheterna och är därmed situationsanpassade.   Nyckelord: Företagsförvärv, integrationsprocessen, formell styrning, informell styrning, institutionella logiker, styrspänningar / Abstract  Master's thesis, Master of Science in Business and Economics - Controller, Linnaeus University School of Business, Växjö, spring semester 2023.  Title: Does one plus one really equals two?  A qualitative case study on how a private organization handles management control tensions after an acquisition.  Background & problem Acquisitions have become a popular approach to achieve fast and high growth. Nevertheless, it has been shown that the majority of acquisitions fail due to the difficulty of integrating the structural, cultural and strategic differences of the companies. To address these differences, it is crucial to design a management control system that considers the systems of the acquiring and acquired firms. However, existing research has not shed light on how firms should construct their control systems following a completed acquisition. The lack of interaction between the two firms eventually led to internal conflicts, also known as management control tensions.  Purpose The purpose of this study is to examine an organization's management control system both during and after a business acquisition. Particular attention has been given to identify and illustrate the tensions that have arisen in management control and to investigate the underlying reasons for their emergence. Finally, the investigation also aims to find and explain how these tensions in management control are handled within a private organization.  Method The research has investigated a private organization that carries out corporate acquisitions. The starting point for this investigation has been through a qualitative research approach with semi-structured interviews, where a case study with an explanatory character has been applied. The empirical collection has been obtained from both the acquiring and acquired companies' employees. In addition, internal documents and annual reports have been used to complement the empirical material of the study.  Conclusion The study identified five management tensions that have arisen after acquisitions; "Power to employees vs Formal structures", "Old systems vs New systems", "Old monitoring procedures vs New monitoring procedures," "Old benefits vs New benefits", "Old identity vs New identity". The emergence of these management control tensions is explained on the basis that there are contrasts in the management control systems of the acquiring and acquired company. Moreover, it is because the acquired employees had expectations that were not met after the acquisition. In addition, institutional logics have been another contributing factor, with one logic weakening the other. How these five management control tensions have been tackled depends on the circumstances and is thus context dependent.  Keywords: Mergers and acquisitions, integration process, formal controls, informal controls, institutional logics, management control tensions

<p>This thesis experimentally investigates the geometry of a high-speed subsonic planar jet impinging orthogonally on a large, rigid plate at some distance downstream. This geometry has been found to be liable to the production of intense narrowband acoustic tones produced by self-excited flow oscillations for a range of impingement ratio, Mach number and nozzle thickness. Self-excited flows and acoustic tones were found to be generated in two distinct flow regimes: a linear regime occurring at relatively low Mach number, and a fluid-resonant regime occurring at higher Mach numbers. The linear regime has been found to generate acoustic tones exhibiting relatively low pressure amplitudes with frequencies which scale approximately linearly with increasing Mach number, and is produced by a traditional feedback mechanism, whereas tones within the fluid-resonant regime are produced by coupling between the unstable hydrodynamic modes of the jet and trapped acoustic modes occurring between the nozzle and the plate, and produce tones at significantly larger amplitudes. Coupling with these trapped acoustic modes was found to dominate the self-excited response of the system in the fluid-resonant regime, with the frequencies of these acoustic modes determining the unstable mode of the jet being excited, and with the impingement ratio of the flow having only minor effects related to the convection speed. Phase-locked PIV measurements have revealed that self-excited flow oscillations in the fluid-resonant regime are produced by a series of five anti-symmetric modes of the jet, along with a single symmetric mode occurring for small impingement ratios. The behavior of large coherent flow structures forming in the flow has been investigated and quantified, and this information has been used to develop a new feedback model, which can be used to accurately predict the self-excited flow oscillation of the jet.</p> / Doctor of Philosophy (PhD)

<p>This thesis investigates the characteristics of a long aspect ratio synthetic jet actuator and its application for the active control of the vibrations of the downstream cylinder in a tandem cylinder arrangement.</p> <p>A long aspect ratio synthetic jet is produced through an axial slit along part of the length of a cylinder. The jet is excited acoustically by a pair of loudspeakers mounted at the cylinder terminations. The study compares between the performance of two different slits with aspect ratios of 273 and 773. The comparison is based on the spanwise distribution of the mean jet velocity and phase between the jet velocity fluctuations and the excitation signal. Three different frequencies and amplitudes are used to excite the speakers covering the range of frequencies used in the control application.</p> <p>For both cases studied the mean centerline velocity of the jet increases with increasing the amplitude of the exciting signal, but decreases with increasing its frequency. Moreover, velocity deficits of up to 30% are evident as the midspan of the cylinder is approached from either end. Similar trends are also observed for the centerline phase distributions of the velocity fluctuations, with deficits of up to 130°. However, it is observed that for the long slit case the deficits in both the velocity and phase distributions are much larger than those for the short one.</p> <p>The synthetic jet is then mounted in the upstream cylinder of a tandem cylinder arrangement to be used as a control actuator for controlling the vibrations of the downstream cylinder. A simple feedback control mechanism is used at a Reynolds</p> <p>number of about 6.3x104. This Reynolds number corresponds to the case where the iii</p> <p>downstream cylinder’s response is dominated with two frequency components, one at the resonance frequency of the cylinder, which is excited by broadband turbulence in the flow, and the other at the vortex shedding frequency. Both slits studied for the characterization experiments are used to compare their performance as control actuators.</p> <p>Both jets produce comparable reductions in the vibration of the downstream cylinder. A reduction of about 20% in the total RMS amplitude of the vibrations signal is achieved. This amounts to a reduction of about 50% in the resonant peak and an average value of about 40% in the vortex shedding peak. The optimal values of gain and time lag of the controller are then used to investigate the effect of the jet on the flow. It is found that the short slit jet produced an effect that was traced up to 1.875 diameters downstream, while the effect of the long slit jet dropped dramatically very close to the upstream cylinder.</p> / Master of Applied Science (MASc)

<p>A decentralized discrete-event system (DES) consists of supervisors that are physically distributed. Co-observability is one of the necessary and sufficient conditions for the existence of a decentralized supervisors that correctly solve the control problem. In this thesis we present a state-based definition of co-observability and introduce algorithms for its verification. Existing algorithms for the verification of co-observability do not scale well, especially when the system is composed of many components. We show that the implementation of our state-based definition leads to more efficient algorithms.</p> <p>We present a set of algorithms that use an existing structure for the verification of state-based co-observability (SB Co-observability). A computational complexity analysis of the algorithms show that the state-based implementation of algorithms result in quadratic complexity. Further improvements come from using a more compact way of representing finite-state machines namely Binary Decision Diagrams (BDD).</p> / Master of Science (MSc)

One of the most commonly used mechanical systems is the internal combustion engine. Internal combustion engines dominate the automotive industry, and have numerous other applications in generation, transportation, etc. This thesis presents the development of a fault detection and diagnosis (FDD) system for use with an internal combustion engine valve train. A FDD system was developed with a focus on the valve impact amplitudes. Engine cycle averaging and band-pass filtering methods were tuned and utilized for improving the signal to noise ratio. A novel feature extraction method was developed that included a local RMS sliding window method and an adaptive threshold. Faults were seeded in the form of deformed valve springs, as well as abnormal valve clearances. The engine’s manufacturer specifies that a valve spring with 3 mm or more of deformation should be replaced. This thesis investigated the detection of a relatively small 0.5mm spring deformation. Valve clearance values were adjusted 0.1mm above and below the nominal clearance value (0.15mm) to test large clearance faults (0.25mm) and small clearance faults (0.05mm). The performance of the FDD system was tested using an instrumented diesel engine test bed. A comparison of numerous signal processing techniques and classification methods was performed. / Master of Applied Science (MASc)

Humans learn to interact with many complex dynamic systems such as helicopters, bicycles, and automobiles. This dissertation develops a subsystem identification method to model the control strategies that human subjects use in experiments where they interact with dynamic systems. This work provides new results on the control strategies that humans learn. We present a novel subsystem identification algorithm, which can identify unknown linear time-invariant feedback and feedforward subsystems interconnected with a known linear time-invariant subsystem. These subsystem identification algorithms are analyzed in the cases of noiseless and noisy data. We present results from human-in-the-loop experiments, where human subjects in- teract with a dynamic system multiple times over several days. Each subject’s control behavior is assumed to have feedforward (or anticipatory) and feedback (or reactive) components, and is modeled using experimental data and the new subsystem identifi- cation algorithms. The best-fit models of the subjects’ behavior suggest that humans learn to control dynamic systems by approximating the inverse of the dynamic system in feedforward. This observation supports the internal model hypothesis in neuro- science. We also examine the impact of system zeros on a human’s ability to control a dynamic system, and on the control strategies that humans employ.

Transmissibility is the most common metric used for isolator characterization. However, engineers are becoming increasingly concerned about energy transmission through an isolator at high frequencies and how the compliance of the machine and foundation factor into the performance. In this study, the transfer matrix approach for isolator characterization is first reviewed. Two methods are detailed for determining the transfer matrix of an isolator using finite element simulation. This is accomplished by determining either the mobility or impedance matrix for the isolator and then converting to a transfer matrix. One of the more useful metrics to characterize the high frequency performance of an isolator is insertion loss. Insertion loss is defined as the difference in transmitted vibration in decibels between the unisolated and isolated cases. Insertion loss takes into account the compliance on the source and receiver sides. Accordingly, it has some advantages over transmissibility which is a function of the damping and mounted resonant frequency. A static analysis is to preload the isolator so that stress stiffening is accounted for. This is followed by modal and forced response analyses to identify the transfer matrix of the isolator. In this paper, the insertion loss of spring isolators is examined as a function of several geometric parameters including the spring diameter, wire diameter, number of active coils, and height. Results demonstrate how modifications to these parameters affect the insertion loss and the first surge frequency.

Cranes are used to lift and move large objects in a wide variety of applications at constructions sites, shipping ports, and manufacturing facilities, etc. If the load to be moved is too long or heavy for a single crane, then two, or more, cranes must work in cooperation to move the payload. In a factory setting this can be accomplished using two trolleys running along the same bridge forming a dual hoist crane. Using two hoists not only increases lifting capacity, it also improves stability of the payload over traditional single hoist configurations. This research takes advantage of that increased stability and explores a novel application for dual hoist cranes: suspending a robot arm from the two trolleys. This increases the workspace of the robot to the entirety of the space covered by the crane, opening up numerous applications not possible with a stationary robot. In order to better understand and characterize the dynamics of the system, a numerical model was developed and tested against a physical system to confirm its validity. A vision system has the potential to greatly increase the usefulness of a robotic system such as the one presented in previous paragraph. The Asus Xtion was used in this work due to its versatility and low cost. An evaluation of this sensor was performed. Various tests were conducted to determine its accuracy in a range of scenarios. It was found that crane oscillations degraded the quality of data returned. This is effect is especially detrimental if the crane is moved to a specified point and sensing begins immediately. The data collection process could be delayed until the residual oscillations subside, however the time penalty incurred by waiting is large because the oscillations are lightly damped and have a long period. To address this issue a control method called input shaping was introduced to reduce the residual oscillations thereby increasing the quality of the sensor data. Finally, two promising uses of the robot arm dual-hoist crane system were introduced: painting and sandblasting. The efficiency of a factory equipped with this system can be increased at relatively low cost by automating manual tasks such as these.