In modern society, car manufactures are actively pursuing vehicle light weighting under both stricter government regulations due to environmental concerns and consumers’ demand for better fuel economy. Under such circumstances, OEMs are using more parts using aluminum alloys to replace parts made with steel. New forming processes are being developed to produce structural components to achieve higher in-service strength using higher strength aluminum alloys. Two of the commonly used high strength aluminum alloys, AA6111 and AA7075, are being considered for elevated temperature sheet forming applications. With more aluminum applications in vehicle and good recyclability of aluminum components, there is a concern of contamination from transition metals such as Fe, Mn and Cr from vehicle end of life scraps getting into aluminum scrap stream. Such impurity elements can have profound impact on aluminum alloy’s mechanical properties, performance and formability at room and elevated temperatures. This study is focused on variants of AA6111 and AA7075 alloys with increased recycling content, and thus higher amounts of the above transition metals. The objective is to investigate the effect of impurity alloying elements on final microstructure, mechanical properties and formability of the above sheet materials. Formability is studied in terms of sheet bendability and elevated temperature forming limit diagrams (FLDs) using a hot gas bulge tester. / Thesis / Master of Applied Science (MASc)

The thesis examines the design and implementation of a supervisory controller for the energy management of an AC stand-alone microgrid. The microgrid under study consists of a photovoltaic (PV), battery energy storage system (BESS) and auxiliary (micro gas turbine) units connected to a common AC bus and supplies a local load. The BESS unit has to maintain the AC bus voltage and frequency and needs to balance the difference between the intermittent PV power and that consumed by the load. However, the BESS has limited energy capacity and power rating and therefore it is important to implement a supervisory controller that can curtail the PV power to prevent the battery from being overcharged and also to operate the auxiliary unit to prevent the battery from being over discharged. A Fuzzy Logic Controller (FLC) that can be implemented inside the BESS unit is proposed. It monitors the battery power and State of Charge (SOC) and varies the bus frequency accordingly. The variation in the bus frequency serves as a communication means to the PV and auxiliary units. If the frequency is increased above the nominal value, the PV unit starts to curtail its power and if the frequency is decreased, the auxiliary unit starts to generate power. Power curtailment and supplement are proportional to the frequency variation. In order to avoid any need for communication links between the units, the DC/AC inverters of all the units adopt the well-known wireless droop technique. The droop control of the auxiliary unit is implemented in such a way that the unit is floating on the bus and thus it generates power only if the bus frequency is decreased below its nominal value. The main merits of the proposed controller are simplicity and easiness of implementation inside the BESS unit. The effectiveness of the controller in protecting the battery from over-charging/over-discharging has been verified by simulations including a real-time simulation and experimentally. Furthermore, the thesis investigates the effect of sudden shading of a PV and concentrated PV (CPV) on the bus frequency of an AC stand-alone microgrid. It is known that the CPV power can drop drastically, compared to traditional PV, when it is exposed to shading. A simulation model of the CPV in a microgrid has been built and the results are compared to those of the traditional PV. It is found that shading of the CPV has much more stronger effect on the bus frequency.

No description available.

Active safety systems for road vehicles have been improved considerably in recent years along with technological advances and the increasing demand for road safety. In the development route of active safety systems which started with introduction of digital controlled ABS in the late seventies, vehicle stability control systems have been developed which today, with an integration approach, incorporate ABS and other previously developed active safety technologies. ABS, as a main part of this new structure, still maintains its importance. In this thesis, a design methodology of an antilock braking system controller for four wheeled road vehicles is presented with a detailed simulation work. In the study, it is intended to follow a flexible approach for integration with unified control structure of an integrated active safety system. The objective of the ABS controller, as in the previous designs in literature, is basically to provide retention of vehicle directional control capability and if possible shorter braking distances by controlling the wheel slip during braking. iv A hierarchical structure was adopted for the ABS controller design. A high-level controller, through vehicle longitudinal acceleration based estimation, determines reference slip values and a low-level controller attempts to track these reference slip signals by modulating braking torques. Two control alternatives were offered for the design of the low-level controller: Fuzzy Logic Control and PID Control. Performance of the ABS controller was analyzed through extensive simulations conducted in MATLAB/Simulink for different road conditions and steering maneuvers. For simulations, an 8 DOF vehicle model was constructed with nonlinear tires.

Active vehicle safety systems for road vehicles play an important role in accident prevention. In recent years, rapid developments have been observed in this area with advancing technology and electronic control systems. Active yaw control is one of these subjects, which aims to control the vehicle in case of any impending spinning or plowing during rapid and/or sharp maneuver. In addition to the development of these systems, integration and cooperation of these independent control mechanisms constitutes the current trend in active vehicle safety systems design. In this thesis, design methodology and simulation results of an active yaw control system for two axle road vehicles have been presented. Main objective of the yaw control system is to estimate the desired yaw behavior of the vehicle according to the demand of the driver and track this desired behavior accurately. The design procedure follows a progressive method, which first aims to design the yaw control scheme without regarding any other stability parameters, followed by the development of the designed control scheme via taking other stability parameters such vehicle sideslip angle into consideration. A two degree of freedom vehicle model (commonly known as &ldquo / Bicycle Model&rdquo / ) is employed to model the desired vehicle behavior. The design of the controller is based on Fuzzy Logic Control, which has proved itself useful for complex nonlinear design problems. Afterwards, the proposed yaw controller has been modified in order to limit the vehicle sideslip angle as well. Integration of the designed active yaw control system with other safety systems such as Anti-Lock Braking System (ABS) and Traction Control System (TCS) is another subject of this study. A fuzzy logic based wheel slip controller has also been included in the study in order to integrate two different independent active systems to each other, which, in fact, is a general design approach for real life applications. This integration actually aims to initiate and develop the integration procedure of the active yaw control system with the (ABS). An eight degree of freedom detailed vehicle model with nonlinear tire model is utilized to represent the real vehicle in order to ensure the validity of the results. The simulation is held in MATLAB/Simulink environment, which has provided versatile design and simulation capabilities for this study. Wide-ranging simulations include various maneuvers with different road conditions have been performed in order to demonstrate the performance of the proposed controller.

Active safety systems for road vehicles make a crucial preventive contribution to road safety. In recent years, technological developments and the increasing demand for road safety have resulted in the integration and cooperation of these individual active safety systems. Traction control system (TCS) is one of these individual systems, which is capable of inhibiting wheel-spin during acceleration of the vehicle on slippery surfaces. In this thesis, design methodology and simulation results of a traction control system for four wheeled road vehicles are presented. The objective of the TCS controller is basically to improve directional stability, steer-ability and acceleration performance of vehicle by controlling the wheel slip during acceleration. In this study, the designed traction control system based on fuzzy logic is composed of an engine torque controller and a slip controller. Reference wheel slip values were estimated from the longitudinal acceleration data of the vehicle. Engine torque controller determines the throttle opening angle corresponding to the desired wheel torque, which is determined by a slip controller to track the reference slip signals. The wheel torques delivered by the engine are compensated by brake torques according to the desired wheel torque determined by the slip controller. Performance of the TCS controller was analyzed through several simulations held in MATLAB/Simulink for different road conditions during straight line acceleration and combined acceleration and steering. For simulations, an 8 DOF nonlinear vehicle model with nonlinear tires and a 2 DOF nonlinear engine model were built.

As Civil Engineering structures, e.g., tall buildings, long span bridges, deep water offshore platforms, nuclear power plants, etc., have become more costly, complex and serve more critical functions, the consequences of their failure are catastrophic. Therefore, the protection of these structures against damage induced by large environmental loads, e.g., earthquakes, strong wind gusts and waves, etc., is without doubt, a worldwide priority. However, structures cannot be designed to withstand all possible external loads and some extraordinary loading episodes do occur, leading to damage or even failure of the structure. Protection of a structure against hazards can be achieved by various means such as modifying structural rigidities, increasing structural damping, and by attaching external devices, known as control devices. Control devices can be deployed either to isolate the structure from external excitation or to absorb input seismic energy to the structure (absorber) so as to mitigate vibration in the primary structure. Seismic base isolation is one such mechanism which isolates a structure from harmful ground excitations. Seismic base isolation is a widely accepted and implemented structural control mechanism due to its robustness and ease in deployment. Following the Northridge earthquake (1994), and Kobe earthquake (1995), the interest of structural engineers in understanding near-source ground motions has enhanced. Documents published after these earthquakes emphasized the issue of large base displacements because of the use of none or little isolation damping (of viscous type only) prior to these events. More recent studies have investigated analytically and experimentally, the efficiency of various dissipative mechanisms to protect seismic isolated structures from recorded near-source long period, pulse-type, high velocity ground motions. Consequently, hybrid isolation systems, seismic base isolation supplemented with damping mechanisms, have become the focus of current research trend in structural vibration control. Hybrid base isolation system incorporating passive supplemental damping devices like, viscous fluid dampers, etc., performs satisfactorily in minimizing isolator displacement but at the same time increases superstructure acceleration response. Furthermore, the passive system can be tuned to a particular frequency range and its performance decreases for frequencies of excitation outside the tunning bandwidth. In such a scenario, active control devices in addition to base isolation mechanism provide better performance in reducing base displacement and superstructure acceleration for a broad range of excitation frequencies. Tremendous power requirement and the possibility of power failure during seismic hazards restrict the usage of active systems as a supplemental device. Semi-active devices provide the robustness of passive devices and adaptive nature of active devices. These characteristics make them better suited for structural control applications. The recent focus is on the development of magnetorheological (MR) dampers as semi-active device for structural vibration control applications. MR dampers provide hysteretic damping and can operate with battery power. The thrust of this thesis is on developing a hybrid base isolation mechanism using MR dampers as a supplemental damping device. The use of MR damper as a semi-active device involves two steps; development of a model to describe the MR damper hysteretic behaviour; development of a proper nonlinear control algorithm to monitor MR damper current / voltage supply. Existing parametric models of MR damper hysteretic behaviour, e.g., Bouc-Wen model, fail to consider the effect of amplitude and frequency of excitation on the device. Recently reported literature has demonstrated the necessity of incorporating amplitude and frequency dependence of MR damper models. The current/voltage supply as the input variable to the MR damper restricts the direct use of any control algorithms developed for active control of structures. The force predicted by the available control algorithms should be mapped to equivalent current/voltage and then to be fed into the damper. Available semi-active algorithms in the literature used ‘on-off’ or ‘bang-bang’ strategy for MR applications due to nonlinear current/voltage-force relation of MR damper. The ‘on-off’ nature of these algorithms neither provides smooth change in MR damper current/voltage input nor considers all possible current/ voltage values within its minimum to maximum range. Secondly, these algorithms fail to consider the effect of the MR damper applied and commanded current/voltage dynamics. The thrust of this dissertation is to develop semi-active control algorithms to monitor MR damper supply current/voltage. The study develops a Bouc-Wen based model to characterize the MR damper hysteretic phenomenon. Experimental results and modeling details have been documented. A fuzzy based intelligent control and two model-based nonlinear control algorithms based on optimal dynamic inversion and integral backstepping have been developed. Performance of the fuzzy logic based intelligent control has been explored using experimental investigation on a three storey base isolated building. Further the application of the proposed controllers on a benchmark building; a benchmark highway bridge and a stay cable vibration reduction have been discussed. Experimental study has revealed that the performance of optimal FLC is better than manually designed FLC in terms of reducing base displacement and storey accelerations. The performance of both the FLCs (simple FLC and genetic algorithm based optimal FLC) is better than ‘passive-off’ (zero ampere current supply) and ‘passive-on’ (one ampere current supply) condition of MR damper applications. The ‘passive-off’ results have shown higher base displacements with lower storey accelerations, whereas, the ‘passive-on’ results have reduced base displacement to the least but at the same time increased the storey acceleration too much. The FLC monitored MR damper show a compromise between the two passive conditions. Analytical results confirm these observations. Numerical simulations of the base isolated building with the two model based MR damper control algorithms developed have shown a better performance over FLC and widely used clipped optimal algorithms. The applications of the proposed semi-active control algorithms (FLC, dynamic inversion and integral backstepping) have shown better performance in comparison to that of control algorithms provided with the benchmark studies.

No description available.

In direct teleoperation the interface is vital to control a robot. Often it is reduced to a simple controller and the feedback provided by a camera stream in a monitor which leads to poor results. A telepresence system combined with a Free Look Control is proposed to increase the result in terms of situational awareness, usability and comfort. The telepresence system provides the sense of depth to the operatorin several manners. Free Look Control replaces Tank Control as control mode, in which the robot can be driven in any direction and the operator takes the control of the camera. A synergy is found when both features are implemented together as their advantages are increased. In addition a multi-camera setup is created, in order to build the 3D environment shown to the operator, which is calibrated in an automatic way. The two different control modes are tested and compared by several people. The outcome shows how the inclusion of these characteristics improve the result of the teleoperation in a visible way.

Open Platform Communication Unified Architecture, or OPC UA, is a world-leading communication protocol specializing in unifying and automating production systems communication. In 2018 the OPC Foundation, an industrial consortium, started the OPC UA Field eXchange initiative to develop the current protocol to extend the reach of the communication down to field level devices like sensors and actuators. This paper explores whether OPC UA FX software can be implemented and integrated with HMS Networks’ product AnyBus CompactCom M40.  The problem formulation stems from the future need for factory communication. For factories to compete, they need to adapt and keep up with the technological progression. OPC UA FX is based on decentralized communication where devices transmit data to each other by distributing the load over the entire system.   The purpose of this report is to, based on the Open62541 implementation, develop software that extends OPC UA with PubSub functionality and methods that enable two or more instances to run as an FX application, meaning that the program publishes and subscribes data simultaneously. Once the software is developed, we integrate it on an AnyBus CompactCom 40 module. This will work as a communication prototype that proves that it is possible to extend OPC UA with FX into HMS Networks’ products.  Open62541 is used to gather libraries and methods needed for OPC UA development. The software is developed using C in Visual Studios and integrated into the hardware using Eclipse.  The result in the form of software was a connection-oriented data exchange, based on the OPC UA information model, where two or more instances can publish and subscribe to information simultaneously. HMS Networks can use the result on their way to implementing OPC UA FX in their products.  In conclusion, the Open62541 implementation is beneficial when developing the OPC UA protocol. The software is complete, but it could not be fully integrated into the CompactCom module. The achieved application is still useful for the development of HMS Network’s products that might use the protocol. / Open Platform Communication Unified Architechure, eller OPC UA, är ett av de världsledande kommunikationsprotokoll som är specialiserat i att förena kommunikation i produktionssystem. 2018 startade OPC Foundation, ett industriellt konsortium, ett initiativ vid namn OPC UA Field eXchange med målet att utvekcla det nuvarande protokollet så att det kan användas till kommunikation på låg nivå, exempelvis mellan sensorer och ställdon. Denna rapport utforskar ifall det är möjligt att utveckla protokollet och integrera det i HMS Networks modul AnyBus CompactCom 40.  Problemformluleringen baseras på framtida behov hos fabriker relaterat till automatisering. För att konkurrera framöver behöver fabriker anpassa sig till utvecklingen inom automatisering. OPC UA FX fokuserar på decentralierad kommunikation mellan enheter som fältanordning, maskin och moln samtidigt för att belastningen ska delas upp över hela systemet. Samtidigt som enheter i industiella nätverket fritt ska kunna överföra data mellan varandra oberoende vilken tillverkare som skapat enheten.   Syftet med arbetet är att, baserat på Open62541, utveckla PubSub teknologi med metoder som möjlighetsgör att två eller fler instanser av en FX applikation ska kunna transportera data genom att prenumerera på och publicera data samtidigt. När mjukvaran fungerar är tanken att integrera mjukvaran på en AnyBus CompactCom 40 modul för att bevisa att implementationen är möjlig i ett praktiskt sammanhang.  Open62541 används för att inkludera nödvändiga OPC UA bibliotek, funktionalitet och datatyper. Protokollet utvecklas i C i en VisualStudio miljö och integreras med hjälp av Eclipse. Resultatet i form av mjukvara var en kopplings intriktat data utbyte, baserad på OPC UA information modell, där en eller två instanser av ett program kan publicera och prenumerera på data samtidigt. HMS Networks kan använda resultatet i arbetet att implementera OPC UA FX i deras produkter. ​Sammanfattningsvis är Open62541 ett mycket användbart verktyg för utvekcling av OPC UA protokol. Dessvärre lyckades inte integrationen av mjukvaran i CompactCom modulen helt och hållet, men det som åstadkommits i arbetet kan i hög grad användas för fortsatt utveckling av OPC UA FX i HMS Networks produkter.