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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Alternative Strategies for Engine Control / Alternativa reglerstrategier för motor-reglering

Kahriman, Edin, Jovanovic, Srdjan January 2015 (has links)
The existing powertrain control system in Volvo CE's vehicles consists of various types of physical quantities that are controlled. One of them is the engine speed. The purpose of this thesis is to investigate whether there are other control strategies suitable for engine speed control, than the existing one. Currently, the existing control system requires re-calibration of the control parameters if hardware in the vehicle is replaced. The current controller is a gain-scheduled PID controller with control parameters that varies over the operating range. The aim has been to develop several different adaptive control strategies. Adaptive control methods are expected to adapt to the changes of the system that a replacement of hardware can bring. The performance and robustness of the developed controllers have been compared with the existing controller. The approach has been to implement the control strategies in Matlab/Simulink and simulate the process with existing engine software provided by Volvo CE. The next step was to test and verify the controllers in a real machine. The focus in this thesis work has been on the adaptive control strategies MRAC (Model-Reference Adaptive Control) and L1 Adaptive Control. In the MRAC structure the desired performance is specified in terms of a reference model that the real system is supposed to follow. Each time an error is generated, by comparing actual and desired output, a suitable algorithm is used in order to obtain the control signal that can minimize the error. In addition, modeling errors and disturbances are estimated so that the controller can compensate for these. L1 Adaptive Control is an extension of the MRAC structure. The difference is that before the control signal is fed to the real system, it is low-pass filtered. This is done in order to prevent feeding high frequencies into the system. The results show that adaptive control has potential to be used in engine speed control. Reference following and disturbance rejection is well handled and simulations have furthermore shown that the developed controllers can deal with changes in the hardware. One of the developed L1-controllers was implemented in a real machine with promising results. / Det existerande styrsystemet i Volvo CE:s maskiner har till uppgift att styra och reglera flera olika fysikaliska storheter. En av dessa storheter är motorvarvtalet. Syftet med detta examensarbete är att undersöka alternativa reglerstrategier som kan användas för att styra motorvarvtalet. Problemet idag är att det nuvarande styrsystemet kräver omkalibrering av regulatorparametrar när befintlig hårdvara i maskinen behöver ersättas på grund av föråldring eller slitage. Den nuvarande regulatorn är en parameterstyrd PID-regulator där regulatorparametrarna beror av aktuell arbetspunkt. Målet har varit att utveckla och prova flera olika adaptiva reglerstrategier. Dessa metoder förväntas kunna hantera förändringar och adaptera sig mot nya förhållanden och omständigheter som en hårdvaruförändring kan medföra. Prestanda och robusthet som de utvecklade regulatorerna erhåller har jämförts mot den existerande regulatorstrukturen. Tillvägagångssättet har varit att implementera reglerstrategierna i Matlab/Simulink samt simulera med tillhörande motormjukvara som Volvo CE tillhandahållit. I nästa fas skulle regulatorerna testas och verifieras i en riktig maskin. Fokuset har under detta examensarbete riktats mot de två adaptiva reglerstrategierna Model-Reference Adaptive Control (MRAC) och L1 Adaptive Control. MRAC-strukturen bygger på att specificera prestandan genom en referens-modell som det riktiga systemet skall följa. Varje gång en avvikelse uppstår så beräknas en lämplig styrsignal genom att beakta och försöka minimera skillnaden mellan det riktiga systemet och den önskade referens-modellen. Till detta modelleras och skattas störningar som regulatorn skall kompensera för. Tekniken inom L1 Adaptive Control är en utvidgning av MRAC. Önskat beteende specificeras även för denna regulatorstruktur men största skillnaden är att innan styrsignalen matas in till systemet så lågpassfiltreras den. Detta görs i förebyggande syfte för att inte släppa in onödigt höga frekvenser in i systemet. Resultaten visar att adaptiv reglering av motorvarvtalet har potential. Referensföljning och undertryckning av störningar hanteras väl och simuleringar har dessutom visat att de utvecklade regulatorerna kan hantera hårdvaruändringar. En av de utvecklade L1-regulatorerna implementerades i en riktig maskin och resultaten såg lovande ut.
2

A mathematical model of ram-charging intake manifolds for four stroke diesel engines

Eberhard, Walter Wayne January 1971 (has links)
No description available.
3

Engine Speed Based Estimation of the Indicated Engine Torque / Varvtalsbaserad estimering av indikerat motormoment

Hellström, Magnus January 2005 (has links)
<p>The aim of this master's thesis is to implement and evaluate a method for estimating the indicated engine torque. The method is developed by IAV GmbH, Fraunhofer-Institut and Audi AG. The determination of the indicated torque is based on high resolution engine speed measurements. The engine speed is measured with a hall sensor, which receives the signal from the transmitterwheel mounted on the crankshaft. A transmitterwheel compensation is done to compensate for the partition defects that arises in the production and thus enable a more precise calculation of the angular velocity. The crankshaft angle, angular velocity and angular acceleration are estimated and the helpvariable effective torque is calculated using these signals as input. Through a relationship between effective torque and the indicated pressure the indicated pressure is extracted from a map. The indicated torque is then calculated from the pressure. </p><p>The method is validated with data from an engine test bed. Because of the low obtainable sample rate at the test bed, 4MHz, quantisation errors arises at engine speeds over 1000 rpm. Therefore the model is validated for low engine speeds and the result is promising.</p>
4

Ion Current Dependence on Operating Condition and Ethanol Ratio

Gustafsson, Karin January 2006 (has links)
<p>This masters thesis investigates the possibility to estimate the ethanol content in the fuel using ion currents. Flexible fuel cars can be run on gasoline-ethanol blends with an ethanol content from0 to 85 percentage. It is important for the engine control system to have information about the fuel. In todays cars the measurements of the fuel blend are done by a sensor. If it is possible to do this with ion currents this can be used to detect if the sensor is broken, and then estimate the ethanol content until the sensor gets fixed. The benefit</p><p>of using ion currents is that the signal is measured directly from the spark plug and therefore no extra hardware is needed. To be able to see how the ethanol ratio affects the ion currents, the dependencies of the operating point have been investigated. This has been done by a literature review and by measurements in a Saab 9-3. Engine speed, load, ignition timing, lambda and spark plugs effects on the ion currents are especially studied. A black box model for the ion currents dependence on operating point is developed. This model describes the engine speed, load and ignition timing dependencies well, but it can not be used to estimate the ethanol ratio.</p>
5

Ion Current Dependence on Operating Condition and Ethanol Ratio

Gustafsson, Karin January 2006 (has links)
This masters thesis investigates the possibility to estimate the ethanol content in the fuel using ion currents. Flexible fuel cars can be run on gasoline-ethanol blends with an ethanol content from0 to 85 percentage. It is important for the engine control system to have information about the fuel. In todays cars the measurements of the fuel blend are done by a sensor. If it is possible to do this with ion currents this can be used to detect if the sensor is broken, and then estimate the ethanol content until the sensor gets fixed. The benefit of using ion currents is that the signal is measured directly from the spark plug and therefore no extra hardware is needed. To be able to see how the ethanol ratio affects the ion currents, the dependencies of the operating point have been investigated. This has been done by a literature review and by measurements in a Saab 9-3. Engine speed, load, ignition timing, lambda and spark plugs effects on the ion currents are especially studied. A black box model for the ion currents dependence on operating point is developed. This model describes the engine speed, load and ignition timing dependencies well, but it can not be used to estimate the ethanol ratio.
6

Engine Speed Based Estimation of the Indicated Engine Torque / Varvtalsbaserad estimering av indikerat motormoment

Hellström, Magnus January 2005 (has links)
The aim of this master's thesis is to implement and evaluate a method for estimating the indicated engine torque. The method is developed by IAV GmbH, Fraunhofer-Institut and Audi AG. The determination of the indicated torque is based on high resolution engine speed measurements. The engine speed is measured with a hall sensor, which receives the signal from the transmitterwheel mounted on the crankshaft. A transmitterwheel compensation is done to compensate for the partition defects that arises in the production and thus enable a more precise calculation of the angular velocity. The crankshaft angle, angular velocity and angular acceleration are estimated and the helpvariable effective torque is calculated using these signals as input. Through a relationship between effective torque and the indicated pressure the indicated pressure is extracted from a map. The indicated torque is then calculated from the pressure. The method is validated with data from an engine test bed. Because of the low obtainable sample rate at the test bed, 4MHz, quantisation errors arises at engine speeds over 1000 rpm. Therefore the model is validated for low engine speeds and the result is promising.
7

Lógica `Fuzzy aplicada ao controlador de velocidade de uma linha de montagem de eixos de veículos

Sérgio Roberto Pinton Saragioto 15 December 2012 (has links)
Nos últimos tempos, as empresas de manufatura tiveram profundas alterações nos ambientes de atuação promovendo novos desafios, como atender aos clientes atingindo melhores resultados. Fatores como estes conduzem as organizações a adaptações significativas, redefinindo as estratégias básicas de manufatura, de maneira a se reposicionar, formando uma condição competitiva, sejam nos serviços e processos fabris. Um dos processos frequentes nas organizações são as montagens, e por isto teve foco neste trabalho. Este trabalho teve como objetivo definir uma sistemática de controle da velocidade do motor de uma linha de montagem para aumentar a produtividade. Esta sistemática foi estabelecida por meio de agregação de tecnologias robustas, capazes de incorporar vantagens competitivas no ambiente da manufatura. Esta aplicação foi definida em um modelo de produção com amplo leque de materiais, com um portfólio de produtos diversificado, com flutuações de demanda, complexas combinações de mix e singularidade operacional. Para atingir este resultado, diversas áreas de conhecimentos foram pesquisadas, como por exemplo, os pilares da manufatura competitiva associados aos modelos customizados, o dimensionamento das atividades dos montadores por meio dos tempos de processos, o rendimento deles diante dos fatores temporais e as características correlatas envolvidas junto ao ambiente de trabalho. O rendimento dos montadores, por sua vez, requereu pesquisas junto ao ambiente de montagem. Com base nestes conhecimentos foi aplicado a lógica `fuzzy como instrumento de formação do controle, obtendo dois significativos ganhos: a redução dos tempos de montagens nas operações, minimizando os tempos ociosos decorrente ao processo e a diversificação do mix e volume do portfólio de produtos. O outro ganho obtido esta associado ao efeito do rendimento humano dos montadores. Este foi equalizado com as atividades produtivas durante o decorrer da jornada de trabalho. Devido ao perfil do processo singular, com notórias características de manufatura customizada e com diversas combinações de produtos na sequência de montagem, a redução dos tempos foi quantificada por meio de um modelo de simulação de manufatura discreta, elaborado com o software ARENA*, que comprovou um ganho de produtividade na ordem de 4%. Validando assim o empregando a lógica `fuzzy do tipo 1 para a sistemática do controle do motor da linha de montagem de eixos para veículos comerciais. / Recently, manufacturing companies have had profound changes in work environments promoting new challenges such as serving customers reaching best results. Factors like these leading organizations to significant adjustments, redefining the basic strategies of manufacturing in order to reposition itself, forming a competitive condition, whether in services and manufacturing. One of the processes in organizations are frequent assemblies, and therefore had focus in this work. This study aimed to define a systematic control of motor speed of an assembly line to increase productivity. This system was established through aggregation of robust technologies, capable of incorporating competitive advantages in the manufacturing environment. This application has been defined in a production model with wide range of materials, with a diversified product portfolio with demand fluctuations, complex combinations of mix and operational uniqueness. To achieve this result, various areas of expertise were researched, as for example, the pillars of competitive manufacturing customized templates associated with the dimensioning of the assemblers activities through times of processes, the yield on these factors and temporal characteristics related involved with the working environment. The yield of the assemblers in turn, applied to the environment surveys assembly. Based on this knowledge was applied to `fuzzy logic as a tool for training control, obtaining two significant gains: reducing assembly time operations, minimizing downtime due to process and the diversity and volume of the product portfolio. The other observed gain associated with this income effect of human assemblers. This was equalized with productive activities during the course of the workday. Due to the unique profile of the process, with notorious features custom manufacturing and with various combinations of products in the assembly sequence, the time reduction was quantified through a simulation model of discrete manufacturproductivity gain in the order of the 4%. Validating thus the employing `fuzzy logic of type 1 for the systematic control of the engine assembly line of axles for commercial vehicles.
8

Návrh systému regulace vrtule stálých otáček / Design of regulation system for constant speed propeller

Líška, Lukáš January 2014 (has links)
This thesis deals with the design of electrical control for a constant speed propeller. The objective of this paper is to demonstrate the propeller governor design process on a case example of a DMP-3 propeller paired with a Rotax 912 ULS, using knowledge of flight mechanics, electrical engineering and automation. The scope of this thesis addresses the problems of propeller pitch control using an electrically driven linear actuator. In conclusion, this paper compares the benefits of the DMP-3 constant speed propeller, considering its use in existing airplanes within the UL-2 and CS-LSA category. Furthermore, it evaluates the capabilities of the proposed electronic governor, and outlines possibility of further development in this field.
9

Palubní multifunkční jednotka pro motocykly / Multifunction board computer for motorcycles

Netáhlo, Tomáš January 2012 (has links)
Master’s thesis deals with a design and a realization of multifunction board computer for motorcycles. The goal of the device is measuring speed, rotation speed of engine, temperature of ambient, temperature of engine, temperature in intake including signalization of overvoltage and hightemperature. The device is completed by above standard function such as measuring titl of motorcycle, climbing of route, route recording and data transmission to the computer. The thesis includes a complete solution of hardware and software part of the device.

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