Field Programmable Gate Arrays and Reconfigurable Computing in Automatic Control

New combustion engine principles increase the demands on feedback combustion control, at the same time economical considerations currently enforce the usage of low-end control hardware limiting implementation possibilities. Significant development is simultaneously and continuously carried out within the field of Field Programmable Gate Arrays (FPGAs). In recent years FPGAs have developed, from being a device mainly used to implement grids of 'glue-logic' to something of a flexible 'dream device' in cost and performance sensitive applications. It is not solely the development of FPGA devices which has made the FPGA the promising implementation platform it is, development of software tool sets and design methodologies is as important as the device as such. This thesis describes the nature of FPGAs, how they work, which programming environments that are available and which design methodologies that can be used on different levels. Focus is set on implementing control and feedback control on FPGAs in general terms. There are a lot of practical considerations differing between the FPGA environment and the well-known micro-controller environment and those are discussed from the view of the literature available in the different areas. The potential application of FPGAs is described and illustrated with application examples found in the literature, both general applications and control applications are discussed. The intended application is control of internal combustion engines and one FPGA implementation of a modeling algorithm commonly used within automotive control is described and discussed. The intention is to illustrate the usefulness in automotive control applications. Finally a suggestion of a suitable FPGA based automotive-control development environment is treat

An Ultra High Bandwidth Automotive Rapid Prototype System

For developers of automotive control, prototyping and initial tests are a hassle. Commercial solutions are available but the price and especially the price/performance ratio opens the field for more cost effective solutions. Automotive rapid prototype systems seen so far are mainly processor based systems with standard interrupt driven measurement and actuation. Control systems based on high time resolution measurements of for example cylinder pressure are difficult to implement using these systems, neither is it possible to implement controller loops with an extremely high bandwidth in combination with expensive algorithms. Measurement and actuation within the same engine cycle, In Cycle Control (ICC) are not possible. The proposed system is based on a mixed system consisting of one standard x86 processor which is configured through Simulink and a reconfigurable application specific integrated circuit (an FPGA) configured either by relevant FPGA design tools or by Simulink. This layout of the rapid prototype system enables the designer to implement either ICC with very high bandwidth (only limited by the capacity of the injection system) or betweencycle control with medium bandwidth. The aim of this paper is to describe one possible configuration of such a system and to discuss the possible performance outcome of the final system

The Effect of Displacement on Air-Diluted Multi-Cylinder HCCI Engine Performance

The main benefit of HCCI engines compared to SI engines is improved fuel economy. The drawback is the diluted combustion with a substantially smaller operating range if not some kind of supercharging is used. The reasons for the higher brake efficiency in HCCI engines can be summarized in lower pumping losses and higher thermodynamic efficiency, due to higher compression ratio and higher ratio of specific heats if air is used as dilution. In the low-load operating range, where HCCI today is mainly used, other parameters as friction losses, and cooling losses have a large impact on the achieved brake efficiency. To initiate the autoignition of the in-cylinder charge a certain temperature and pressure have to be reached for a specific fuel. In an engine with high in-cylinder cooling losses the initial charge temperature before compression has to be higher than on an engine with less heat transfer. The heat transfer to the combustion chamber walls is affected by parameters such as area-to-volume ratio and in-cylinder gas motion, i.e., turbulence. In this paper the performance of three multi-cylinder HCCI engines with different displacements are compared. The engines are a five-cylinder 1.6dmu3 VCR engine, a four-cylinder 2.0dmu3 engine, and a six-cylinder 11.7dmu3 truck engine. All engines are port fuel injected and run with a RON91/MON82 gasoline. Combustion phasing is mainly controlled with inlet air temperature. The engines have about the same indicated efficiency but different brake efficiency. The truck engine has 32.3% brake efficiency at 2 bar BMEP, followed by the 2.0dmu3 engine with 29.8%, and the 1.6dmu3 VCR engine with only 24.4%

FPGA Based Engine Feedback Control Algorithms

High resolution real time heat release analysis will become increasingly important in the future development of engine control systems. The increased demands on efficiency and emissions will put high demands on future engine control. Future engine concepts, for example the HCCI engine concept might crave cylinder pressure based Closed-Loop Combustion Control (CLCC). The analysis of cylinder pressure is a relatively computationally expensive task that is difficult to implement in existing engine controllers due to the real time demands. This paper describes an approach to obtain such a high speed heat release analysis. The described system could act as a platform for further feedback control experiments. An experimental setup is put together. The heat release algorithm is then developed using MATLAB and SIMULINK. The emerging environment will serve as a prototyping system that can be used for further development of advanced cylinder pressure based feedback control strategies. The performance of the developed algorithm/system is examined in a simulated engine environment. The heart of the system is a Field Programmable Gate Array (FPGA), an FPGA is best described as an reconfigurable Application Specific Integrated Circuit (ASIC). The usage of an FPGA gives the possibility of very high throughput and very low delay time and jitter of the final system. This system could of course also be developed using a normal Commersial Of The Shelf (COTS) processor and a Real Time Operating System (RTOS). The high performance that would be needed to calculate the heat release in the desired time in a multi cylinder engine would however put high demands on the used processor; hence the price of the processor might make the system too expensive, the FPGA describes an alternative approach

Fern genomes elucidate land plant evolution and cyanobacterial symbioses

Li F-W, Brouwer P, Carretero-Paulet L, et al. Fern genomes elucidate land plant evolution and cyanobacterial symbioses. NATURE PLANTS. 2018;4(7):460-472

Embedded Systems and FPGAs for Implementation of Control Oriented Models, Applied to Combustion Engines

Performance demands put on combustion engines are ever increasing, e.g. demands on emissions and fuel consumption. The increased demands together with new combustion concepts increase the need for feedback engine and combustion control. Mathematical models are considered important in order to implement high performance feedback control, as well as to perform diagnostic functions in vehicles. Various implementation platforms which can be used to implement mathematical models in vehicles are described in this this thesis; embedded processors, FPGAs and ASICs. Which of these implementation platforms to choose must be decided based on the intended application and current demands on performance. Embedded systems, ASICs and FPGAs are discussed based on literature found in the field, covering a wide span of considerations. Furthermore a number of considerations which are important when implementing algorithms and logic in embedded processors and FPGAs are described.The theory is put into practice in the thesis, implementing a heat release calculation on an FPGA and developing and implementing a NOx model in an embedded processor. To be able to implement a fast NOx model several techniques were used. Parts of the model were tabulated, difficult operators such as division were avoided and the properties of fast C code was kept in mind. This thesis combines the areas of automatic control, electronic hardware design and development of embedded software, and applies it to combustion engine control. The work undertaken indicate different possibilities when implementing high speed control oriented models in FPGAs and embedded processors. This thesis aims to fill a gap between state space models, common in automatic control, and high fidelity physical models, commonly used for simulation, by providing a method to develop high fidelity control oriented models which are low in computation demand and implementable in FPGAs and embedded processors

Auditor independence based on the threats recognized by IESBA : From a client’s perspective

Inledning Revisorns oberoende är och har varit en omdiskuterad fråga under en lång tid. I Sverige ska en revisor, enligt lag, bekräfta sitt oberoende inför varje nytt uppdrag eller i ett befintligt uppdrag när anledning föreligger, vilket görs med hjälp av analysmodellen. Istället för revisorns uppfattning om sitt oberoende förklarar denna studie hur klienter uppfattar revisorns oberoende med utgångspunkt i analysmodellen. Studien blir unik, dels i och med att klientens uppfattningar är det centrala och dels att studien fokuserar på privata företag. Syfte Syftet med denna studie är att utifrån analysmodellen förklara hur klienter uppfattar revisorns oberoende. Metod Eftersom studien utgår ifrån en deduktiv ansats innebär det att hypoteser har formulerats utifrån tidigare forskning och befintlig teori. En tvärsnittsdesign har använts, då datainsamling har gjorts vid en bestämd tidpunkt. Huvudsakligen har kvantitativ data legat till grund för studien i form av telefonenkäter. Studien har dock kompletterats med kvalitativ data i form av intervjuer med revisorer som har fått ge sin syn på de resultat som framkommit från telefonenkäterna. Slutsats Studiens resultat indikerar att klienter inte uppfattar hotet mot revisorns oberoende som ett problem. Dock har klientens storlek och revisorns ämbetstid signifikanta samband med klientens uppfattning om hotet mot revisorns oberoende. De intervjuade revisorerna förstod våra resultat och tyckte att de stämde väl överens med deras uppfattning om hur det ser ut i praktiken.Prelude Auditor independence is and has been a contentious issue for a long time. InSweden an auditor shall, by law, confirm its independence before any newassignment or in an existing one when needed, which is done by using thethreats recognized by IESBA. Instead of the auditor’s perception of itsindependence this study explains how clients’ perceive auditor independence onthe basis of the threats recognized by IESBA. This study is unique partlybecause of that the client’s perspective is central and partly because of its focuson private firms. Purpose The purpose of this study is that on the basis of the threats recognized by IESBAexplain how clients’ perceive auditor independence. Method Since the study is based on a deductive method this means that hypotheses havebeen formulated on the basis of previous research and existing theory. A crosssectionaldesign was used, because our data collection was made at a given time.Mainly quantitative data, by telephone surveys, has been the basis for the study.However, the study has been supplemented with qualitative data throughinterviews with auditors, who have been given their views on the resultsobtained from the telephone surveys. Conclusion The results of the study indicates that clients’ don’t perceive the threat againstauditor independence as a problem. However, the size of a client and auditortenure have a significant relation with the client’s perception of the threatagainst auditor independence. The interviewed auditors understood our resultsand said they agreed well with their idea of what it looks like in practice

Auditor independence based on the threats recognized by IESBA : From a client’s perspective

Inledning Revisorns oberoende är och har varit en omdiskuterad fråga under en lång tid. I Sverige ska en revisor, enligt lag, bekräfta sitt oberoende inför varje nytt uppdrag eller i ett befintligt uppdrag när anledning föreligger, vilket görs med hjälp av analysmodellen. Istället för revisorns uppfattning om sitt oberoende förklarar denna studie hur klienter uppfattar revisorns oberoende med utgångspunkt i analysmodellen. Studien blir unik, dels i och med att klientens uppfattningar är det centrala och dels att studien fokuserar på privata företag. Syfte Syftet med denna studie är att utifrån analysmodellen förklara hur klienter uppfattar revisorns oberoende. Metod Eftersom studien utgår ifrån en deduktiv ansats innebär det att hypoteser har formulerats utifrån tidigare forskning och befintlig teori. En tvärsnittsdesign har använts, då datainsamling har gjorts vid en bestämd tidpunkt. Huvudsakligen har kvantitativ data legat till grund för studien i form av telefonenkäter. Studien har dock kompletterats med kvalitativ data i form av intervjuer med revisorer som har fått ge sin syn på de resultat som framkommit från telefonenkäterna. Slutsats Studiens resultat indikerar att klienter inte uppfattar hotet mot revisorns oberoende som ett problem. Dock har klientens storlek och revisorns ämbetstid signifikanta samband med klientens uppfattning om hotet mot revisorns oberoende. De intervjuade revisorerna förstod våra resultat och tyckte att de stämde väl överens med deras uppfattning om hur det ser ut i praktiken.Prelude Auditor independence is and has been a contentious issue for a long time. InSweden an auditor shall, by law, confirm its independence before any newassignment or in an existing one when needed, which is done by using thethreats recognized by IESBA. Instead of the auditor’s perception of itsindependence this study explains how clients’ perceive auditor independence onthe basis of the threats recognized by IESBA. This study is unique partlybecause of that the client’s perspective is central and partly because of its focuson private firms. Purpose The purpose of this study is that on the basis of the threats recognized by IESBAexplain how clients’ perceive auditor independence. Method Since the study is based on a deductive method this means that hypotheses havebeen formulated on the basis of previous research and existing theory. A crosssectionaldesign was used, because our data collection was made at a given time.Mainly quantitative data, by telephone surveys, has been the basis for the study.However, the study has been supplemented with qualitative data throughinterviews with auditors, who have been given their views on the resultsobtained from the telephone surveys. Conclusion The results of the study indicates that clients’ don’t perceive the threat againstauditor independence as a problem. However, the size of a client and auditortenure have a significant relation with the client’s perception of the threatagainst auditor independence. The interviewed auditors understood our resultsand said they agreed well with their idea of what it looks like in practice

Management control systems for value co-creation : A study of value and of which management control that is suitable for co-creation

Introduktion: Konceptet samskapande av värde utvecklades inom marknadsföringslitteraturen i början av 2000-talet från Prahalad och Ramaswamy (2000). Redan då betonade författarna att ett företag som strävar efter att samskapa måste anpassa sitt ekonomiska styrsystem efter det. Trots det är forskningen om vilken ekonomisk styrning som kan användas för samskapande bristfällig än idag. Det finns tydliga skillnader mellan fälten där litteraturen om ekonomisk styrning främst utgår från tillverkningsföretag som producerar materiella varor, medan samskapandelitteraturen utgår från att producera tjänster. Samtidigt har de två fälten olika syn på värde, vilket är vad som analyseras i den här uppsatsen för att kunna diskutera vilken ekonomisk styrning som kan användas för samskapande. Syfte: Syftet med uppsatsen är att genom en litteraturstudie beskriva vilka likheter och skillnader som finns i synen på värde mellan ekonomisk styrning och samskapande. Utifrån litteraturstudien och intervjuer analyseras sedan vilken typ av styrning som är främjande för samskapande. Metod: Uppsatsen har en deduktiv ansats där en litteraturstudie utformas. Inledningsvis förs en värdediskussion som analyserar värde inom fälten ekonomisk styrning och samskapande. Utifrån värdediskussionen analyseras sedan tre ekonomiska styrinstrument som kan användas för samskapande. Därefter testas litteraturstudien mot empiri i form av semistrukturerade intervjuer med tre anställda på försäkringsbolaget Folksam. Slutsats: Värdebegreppet inom ekonomisk styrning är aktieägarvärde, vilket skapas genom ett företags interna aktiviteter. Inom samskapandelitteraturen syftar värdebegreppet till kundens upplevda nytta, bruksvärde. Bruksvärde skapas genom kundens användande. Det styrinstrument som slutligen framhävs för samskapande är personlighetsstyrning.Introduction: The concept of value co-creation was developed in marketing literature in the early 2000s by Prahalad and Ramaswamy (2000). Even then, the authors stressed that a company that strives to co-create must adapt its governance systems to it. Despite this, the research on which management control systems that can be used for co-creating is deficient still today. The literature on management control are primarily based on manufacturing companies producing tangible goods, while literature on value co-creation are focusing mainly on services. Furthermore, the perception of value differs among the two research fields, which is what will be analyzed in this paper to discuss which management control systems can be used for co-creation. Aim: The aim of this paper is to create a literature review which describes the similarities and differences in the perception of value among the literature on management control and value co-creation. Based on the literature review and interviews analyze which type of control that promotes co-creation. Methodology: The paper has a deductive approach in which a literature review is designed. Initially, a value discussion is conducted that analyzes the perceptions on value in the fields of management control systems and value co-creation. Based on the value discussion, three types of management controls which could be used for value co-creation will be analyzed. Afterwards, the literature review will be tested against the reality in the form of semi-structured interviews with three employees at the Swedish insurance company Folksam. Conclusion: The value concept within the literature on management control systems refers to shareholder value, which is created through a company’s internal activities. Within the value co-creation literature, the value concept refers to the customer’s perceived benefits, which is called use value. The use value is created when the customer is using the product. The management control that this paper finally highlights is the personnel control