No description available.

This thesis covers the design and prototyping of an electronic throttle control (ETC) system for a small two-stroke engine. The thesis work is being realized in collaboration between a cooperating company and KTH. The throttle control system is veried with a physical combustion engine. The development process of the control systems is being done mostly in-house in the cooperating company. The company has developed electronic control of fuel and ignition system. In addition to the ETC throttle control system this thesis work also develops a control system of the angular velocity of the combustion engine by controlling the intake air to the small two-stroke engine. Today the air supply to the engine is controlled by a valve mechanically connected to the trigger/gas pedal operated by the user. The focus of the thesis is to investigate the advantages and drawbacks of implementing an electronically controlled air supply to a small two-stroke combustion engine. This master thesis discuss the detailed system design requirement of an ETC system for a small two-stroke engine. The result of this master thesis shows that it is possible to have velocity control on a small two-stroke engine, also minor improvements in acceleration of the small combustion engine is shown when using the ETC system. / Detta examensarbete omfattar design och prototypbygge av ett elektroniskt gasreglagesystem (ETC) for en liten tvataktsmotor. Examensarbetet utfors som ett sammarbete mellan ett sammarbetande foretag och KTH. Gasreglagesystemet verieras med en fysisk forbranningsmotor. Utvecklingsprosessen av styrsystemet bedrivs mestadels internt hos det sammarbetande foretaget. Foretaget har utvecklat elektronisk styrning av bransle och tandsystem. Utover det elektroniska gasreglagesystemet har detta examensarbete ocksa behandlat utvecklingen av ett styrsystem av vinkelhastigheten hos forbranningsmotorn genom att styra insugsluften till den lilla tvataktsmotorn. Idag styrs lufttillforseln till forbranningsmotorn av ett spjall som ar mekaniskt ansluten till avtryckaren som manovreras av anvandaren. Fokus for examensarbetet ligger i att undersoka for- och nackdelar med att implementera ett elektroniskt styrt luftspjall till en liten tva-taktsmotor. Examensarbetet behandlar det detaljerade designkravet hos ett ETC system for en liten tvataktsmotor. Resultatet av detta examensarbete visar att det ar mojligt att ha hastighetsstyrning pa en liten tvataktsmotor, aven sma forbattringar i acceleration pavisas nar ETC systemet anvands.

<p>Detta examensarbete utreder en ny typ av spjällhus som optimerats för dragracing. Spjällhuset styr luftflödet till förbränningsmotorn och regleras av gashandtaget. Konceptet är utvecklat av Emtes Ingenjörsbyrå och i examensarbetet ingår att konstruera ett spjällhus med det nya konceptet för motorcykelmodellen Suzuki Hayabusa. Det standardmonterade spjällhuset är anpassat för gatubruk och ett brett effektregister. För dragracing är den maximala effekten avgörande och det standard monterade spjällhuset är en flaskhals vid WOT (Wide Open Throttle).</p><p>För konceptet saknas dock fullständiga lösningar för diverse funktioner. I examensarbetet ingår att komplettera konceptet med en returmekanism, synkroniseringsanordning och erforderliga standarkomponenter. I början av arbetet skall även en kravspecifikation och DFMEA (Design Failure Mode Effects Analysis) upprättas.</p><p>Den slutliga konstruktionen uppfyller de uppsatta kraven enligt krav-specifikationen. Spjällhuset är kompakt, enkelt att montera och anpassat för tillverkning i små serier. Den symmetriska konstruktionen förenklar CNC-tillverkningen (Computer Numerical Control) och sänker tillverknings-kostnaderna.</p><p>Avslutningsvis genomfördes provning för att jämföra det nya spjällhuset med det standardmonterade. Metoden visades vara olämplig och provningen av spjällhuset blev resultatlös. Vidare provning av spjällhuset med andra metoder rekommenderas men lämnas utanför examensarbetet på grund av tids¬begräsningarna.</p> / <p>In this undergraduate thesis a throttle body designed for drag racing is investigated and evaluated. The throttle body governs the air flow to the internal combustion engine and is controlled by the throttle twist grip. The concept is developed by Emtes Engineering and within this undergraduate thesis it includes to design a throttle body with the concept for the motorcycle Suzuki Hayabusa. The standard mounted throttle body is suitable for normal usage and a wide power range. For drag racing the maximum power output is crucial and the standard mounted throttle body is a bottle-neck at WOT (Wide Open Throttle).</p><p>Complete solutions for various functions are missing for the concept. This undergraduate thesis includes completing the concept with a returning mechanism, synchronisation arrangement and proper standard components. At the beginning of the task it also includes to establish a specification of requirements and DFMEA (Design Failure Mode Effects Analysis).</p><p>The final design fulfils the specification of requirements. The throttle body is compact, simple to assemble and suited for small scale manufacturing. The symmetrical design simplifies the CNC-manufacturing (Computer Numerical Control) and thereby reduces the costs.</p><p>Finally a test was carried out to compare the new throttle body with the standard mounted. The methodology turned out to be unsuitable and the testing of the throttle body was without results. Further testing with other methods is recommended but that will not be a part of this undergraduate thesis.</p>

Detta examensarbete utreder en ny typ av spjällhus som optimerats för dragracing. Spjällhuset styr luftflödet till förbränningsmotorn och regleras av gashandtaget. Konceptet är utvecklat av Emtes Ingenjörsbyrå och i examensarbetet ingår att konstruera ett spjällhus med det nya konceptet för motorcykelmodellen Suzuki Hayabusa. Det standardmonterade spjällhuset är anpassat för gatubruk och ett brett effektregister. För dragracing är den maximala effekten avgörande och det standard monterade spjällhuset är en flaskhals vid WOT (Wide Open Throttle). För konceptet saknas dock fullständiga lösningar för diverse funktioner. I examensarbetet ingår att komplettera konceptet med en returmekanism, synkroniseringsanordning och erforderliga standarkomponenter. I början av arbetet skall även en kravspecifikation och DFMEA (Design Failure Mode Effects Analysis) upprättas. Den slutliga konstruktionen uppfyller de uppsatta kraven enligt krav-specifikationen. Spjällhuset är kompakt, enkelt att montera och anpassat för tillverkning i små serier. Den symmetriska konstruktionen förenklar CNC-tillverkningen (Computer Numerical Control) och sänker tillverknings-kostnaderna. Avslutningsvis genomfördes provning för att jämföra det nya spjällhuset med det standardmonterade. Metoden visades vara olämplig och provningen av spjällhuset blev resultatlös. Vidare provning av spjällhuset med andra metoder rekommenderas men lämnas utanför examensarbetet på grund av tids¬begräsningarna. / In this undergraduate thesis a throttle body designed for drag racing is investigated and evaluated. The throttle body governs the air flow to the internal combustion engine and is controlled by the throttle twist grip. The concept is developed by Emtes Engineering and within this undergraduate thesis it includes to design a throttle body with the concept for the motorcycle Suzuki Hayabusa. The standard mounted throttle body is suitable for normal usage and a wide power range. For drag racing the maximum power output is crucial and the standard mounted throttle body is a bottle-neck at WOT (Wide Open Throttle). Complete solutions for various functions are missing for the concept. This undergraduate thesis includes completing the concept with a returning mechanism, synchronisation arrangement and proper standard components. At the beginning of the task it also includes to establish a specification of requirements and DFMEA (Design Failure Mode Effects Analysis). The final design fulfils the specification of requirements. The throttle body is compact, simple to assemble and suited for small scale manufacturing. The symmetrical design simplifies the CNC-manufacturing (Computer Numerical Control) and thereby reduces the costs. Finally a test was carried out to compare the new throttle body with the standard mounted. The methodology turned out to be unsuitable and the testing of the throttle body was without results. Further testing with other methods is recommended but that will not be a part of this undergraduate thesis.

Aircraft-based space-launch platforms allow operational flexibility and offer the potential for significant propellant savings for small-to-medium orbital payloads. The NASA Armstrong Flight Research Center’s Towed Glider Air-Launch System (TGALS) is a small-scale flight research project investigating the feasibility for a remotely-piloted, towed, glider system to act as a versatile air launch platform for nano-scale satellites. Removing the crew from the launch vehicle means that the system does not have to be human rated, and offers a potential for considerable cost savings. Utah State University is developing a small throttled launch-assist system for the TGALS platform. This "stage zero" design allows the TGALS platform to achieve the required flight path angle for the launch point, a condition that the TGALS cannot achieve without external propulsion. Throttling is required in order to achieve and sustain the proper launch attitude without structurally overloading the airframe. The hybrid rocket system employs gaseous-oxygen and acrylonitrile butadiene styrene (ABS) as propellants. This thesis summarizes the development and testing campaign, and presents results from the clean-sheet design through ground-based static fire testing. Development of the closed-loop throttle control system is presented.

The possibility to develop control systems for electromechanical actuators at Scania is studied, in particular the focus is on how to exchange the intelligent actuators used today with dumb ones. An intelligent actuator contains its own control electronics and computational power, bought as a unit from suppliers by Scania and controlled via the CAN bus. A dumb actuator contains no means of controlling itself and its I/O is the motor’s power pins. Intelligent actuators tend to have limited control performance, time delays and poor diagnose systems, along with durability issues. A dumb actuator could have the benefit of avoiding these disadvantages if the system is designed within the company. A literature study concerning the different types of electrical motors available and their control methods is performed, the most suitable for use in a heavy vehicle is deemed the brushless DC motor, BLDC. An intelligent throttle is chosen for a case study and has its control electronics stripped and replaced with new sensor- and control cards. The case study is used to investigate the possibilities and difficulties of this design process. A simulation model is developed for the electronics, motor and the attached mechanical system. With the aid of this model a controller architecture is designed, consisting of PI controllers with feed-forward and torque compensation for nonlinearities. The developed controller architecture is tested and in theory it can compete with the intelligent throttle’s performance. The model is also adapted to allow for code generation. The simulation model is used to study some common electrical faults that can effect the system and the possibilities for diagnosis and fault-remedial actions. The hardware prototype system shows that a current controller is necessary in the control architecture to achieve decent performance and the prototype is developed in such a way as to make future studies possible. The conclusion of the thesis is that Scania would be able to design control systems for dumb actuators, at least from a technical perspective. However more studies, from an economical point of view, will be necessary.

No description available.

The BMW in-line six-cylinder engine has been modified and introduced to production in the new BMW 3 Series model. Its major features include variable intake and exhaust camshaft timing, a new induction system with resonance charging, a turbulence-generating system in the intake ports and a new exhaust system with two closed-loop, coupled catalysts integrated into the exhaust manifold. The cam timing of both camshafts can be adjusted continuously within a range of 40° crank angle (CA) for the inlet cams and 25° CA for the exhaust cams. The turbulence-generating system supplies combustion air to the engine during part load operation and produces the necessary charge motion to run the engine with greater valve overlap at low loads and speeds. Its combination with variable camshaft timing results in lower fuel consumption and exhaust emissions that meet the LEV emission standard. In addition, the variable cam timing raises the torque curve of the unthrottled engine, particularly at low engine speed. The maximum values for torque and power output are unchanged, but maximum torque is reached 500 r/min earlier than with the previous engine.

<p>The objective of the work was to develop a basic control system for an advancedexperimental engine from scratch. The engine this work revolves around is a Saabvariable compression engine.A new control system is developed based on the naked engine, stripped of theoriginal control system. Experiments form the basis that the control system isbuilt upon. Controllers for throttles, intake manifold pressure for pressures lessthan ambient pressure and exhaust gas oxygen ratio are developed and validated.They were found to be satisfactory. The lambda controller is tested with severalparameter sets, and the best set is picked to be implemented in the engine. Modelsnecessary for the development and validation of the controllers are developed.These models include models for the volumetric efficiency, the pressure dynamicsof the intake manifold, the fuel injectors and wall wetting.</p>

<p>When designing a new fuel management system for a spark ignition engine the amount of air that is fed to the cylinders is highly important. A tool that is being used to improve the performance and reduce emission levels is engine modeling were a fuel management system can be tested and designed in a computer environment thus saving valuable setup time in an engine test cell. One important part of the modeling is the throttle which regulates the air. The current isentropic model has been investigated in this report. A throttle body and intake manifold has been simulated using Computational Fluid Dynamics (CFD) and the influence of surface heating and surface wall roughness has been calculated. A method to calculate the effective flow area has been constructed and tested by simulating at two different throttle plate angles and several pressure ratios across the throttle plate. The results show that both surface wall roughness and wall heating will reduce the mass flow rate compared to a smooth and adiabatic wall respectively. The reduction is both dependent on pressure ratio and throttle plate angle. The effective area has showed to follow the same behaviour as the mass flow rate for the larger simulated throttle plate angle 31 degrees, i.e. an increase as the pressure drop over the throttle plate becomes larger. At the smaller throttle plate angle 21 degrees, the behaviour is completely different and a reduction of the effective area can be seen for the highest pressure drop where a increase is expected.</p> / <p>När ett nytt bränslesystem ska designas till en bensinmotor är det viktigt att veta hur stor mängd luft som hamnar i cylindrarna. Ett verktyg som är på frammarsch för att förbättra prestanda och minska emissioner är modellbaserad simulering. Med hjälp av detta kan ett bränslesystem designas och testas i datormiljö och därigenom spara dyrbar tid som annars måste tillbringas i en motortestcell. En viktig del av denna modellering är spjället eller trotteln vilken reglerar luften. I denna rapport har studier gjort på den nuvarande isentropiska modellen. Ett spjällhus och insugsgrenrör har simulerats med hjälp av Computational Fluid Dynamics (CFD) och påverkan av värme samt ytjämnhet på väggen har beräknats. En metod att beräkna den effektiva genomströmmade arean har konstruerats och testats vid två olika spjällvinklar samt flertalet tryckkvoter över spjället. Resultaten visar att både en uppvärmd vägg och en vägg med skrovlighet kommer att minska massflödet jämfört med en adiabatisk respektive en slät vägg. Minskningen har både spjällvinkel samt tryckkvots beroende. Den effektiva genomströmmade arean har visats sig följa samma beteende som massflödet vid den större simulerade spjällvinkeln 31 grader, det vill säga öka med ökat tryckfall över spjället. Vid den mindre vinkeln 21 grader, är beteendet helt annorlunda jämfört med massflödet och en minskning av den effektiva arean kan ses vid det största tryckfallet där en ökning förväntades.</p>