Thesis (PhD) -- University of Alabama, 1997

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on Nov. 16, 2009. "October 2009." "In partial fulfillment of the requirements for the degree [of] Master of Science in Mechanical Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: Charles Birdsong, Ph.D. Includes bibliographical references (p. 76-77).

The purpose of this study is to measure the costs of the perceived safety threat from triple trailer operation in Oregon. This is done using the political referendum model of a common non-market valuation technique, contingent valuation. Specifically, the average cost of allowing triples will be found so that comparison with previously estimated benefits will provide a measure of net social welfare associated with triple trailer use. The data were collected through in-person interviews conducted in five regions in Oregon. Questions relating to the respondents' attitudes toward triple trailer trucks, driving experience, education and other demographics were asked. The empirical model estimates the probability that respondents will vote to ban triple trailers. The results of this study suggest that there are concerns about the safety of triple trailer operation. However, there seem to be still greater benefits; a result which is consistent with the recent ballot measure. / Graduation date: 1995

Manoeuvring a vehicle with additionally attached trailers is a tedious task. Albeit driver assistance systems support the driver in nearly any situation in these days, tools facilitating the manoeuvring process of extended vehicles can only rarely be found in research and especially in the market. This thesis deals with the prototypical implementation of a rear view camera parking assistance system. In particular, the visualisation of the predicted driving path of the tractor-trailer combination in the camera image is emphasised, following the representation of existing parking assistance systems for individual vehicles. A general approach is aiming at the portability of the system to nearly any kind of trailer. The superimposed guidelines are based on a state space model, which is derived on top of assumptions agreeing with results found in the literature. Due to the strong assumptions and simplifications, the model is tested in three different ways and moreover for different types of trailers. All underlying methods are described in detail and furthermore tested in several scenarios, if necessary. Special importance is attached to the comparison of the actual driven paths with their previous predictions, for which a new method has been derived, implemented and tested successfully. Beside the implementation of the guideline projection to the camera’s image, the human-machine interface is augmented by a Bird’s Eye view animation, too. A final test of the integrated system for different types of trailers shows the proper operation of the overall system during parking situations.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographical references.

The effect of configuration changes and add-on devices on the drag reduction of a tractor-trailer is studied through wind tunnel tests using two 1/12-scale models. The configuration changes involve ground clearance, tractor-trailer gap, roof angle and back inclination while add-on devices include flow deflectors, skirts and gap seals. Moving surface boundary layer control as a means of drag reduction is also attempted. Both drag and pressure data are obtained to help identify local contributions. Results suggest that an optimum combination of configuration parameters can reduce drag up to 17% while the add-on devices resulted in a further decrease by a modest amount. The results with moving surface boundary layer control proved to be inconclusive. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

A simulated inner-city training scenario was found to increase skills in the area of turning when compared with a simulated off-track training scenario. To answer this question, two groups of ten participants (5 women and 5 men) were tested using three scripted scenarios focusing on left and right turns. The first training scenario (control group) is an off-track training scenario, which consists of a large asphalt lot and the use of orange cones; the second training scenario (experimental group) is an inner-city training scenario without the presence of vehicular traffic; and the third scenario (test scenario) is an inner-city scenario with the presence of vehicular traffic. A subject matter expert, who is also a former driver and trainer, evaluated and scored all participants on four critical turns (2 left and 2 rights). The apparatus used for this study was the V-sim non-motion simulator from General Electric (GE). A 2 x 4 factorial analysis was utilized to examine conditional differences as well as gender differences. While there were no gender differences, the results for overall turns were significant, F(1, 16) = 7.14, p = .017, η2 = 3.09. The mean for the control group was (M = 20.50, SD = 9.59) with the experimental group at, (M = 31.10, SD = 7.26).

With autonomy becoming a reality for passenger cars, developing an autonomous for tractor-trailers is the next step for driverless roads. Tractor-trailers are heavy, large, and have a pivot joint between the tractor and trailer that makes the movement between the two more complicated. The purpose of the research presented here is to determine the best forward "looking" perception sensor that will see far out enough for the vehicle to stop in time to avoid hitting an object. In order to determine the best sensor, a review of previous sensors and autonomous vehicle sensors will be explored along with the various perception technology. Additionally, a simulation of a tractor-trailer stopping was created to determine the range necessary for a forward perception sensor and when jackknifing may occur. The best brake type for a tractor-trailer will be recommended as well. Finally, the best forward sensor and senor layout for an autonomous tractor-trailer is made based upon the simulation results for the stopping distance of a tractor-trailer. The work, however, is not fully complete. A discussion of the future work and validation of the sensors selected will give future research goals. / Master of Science / With autonomy becoming a reality for passenger cars, developing an autonomous for tractor-trailers is the next step for driverless roads. Tractor-trailers are heavy, large, and have a pivot joint between the tractor and trailer that makes the movement between the two more complicated. The purpose of the research presented here is to determine the best forward “looking” perception sensor that will see far out enough for the vehicle to stop in time to avoid hitting an object. In order to determine the best sensor, a review of previous sensors and autonomous vehicle sensors will be explored along with the various perception technology. Additionally, a simulation of a tractor-trailer stopping was created to determine the range necessary for a forward perception sensor and when jackknifing may occur. The best brake type for a tractor-trailer will be recommended as well. Finally, the best forward sensor and senor layout for an autonomous tractor trailer is made based upon the simulation results for the stopping distance of a tractor-trailer. The work, however, is not fully complete. A discussion of the future work and validation of the sensors selected will give future research goals.

Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.

Laxå Special Vehicles (LSV) är ett företag som har ett starkt samarbete med Scania. De modifierar och bygger olika delar till Scanias lastbilar, bland annat hytter. Scania har uppdaterat hytternas design och verksamheten i Laxå har tvingats expandera med en ny lokal i samma område. Den nya produktionen kommer kräva stor yta och LSV kommer få ont om buffertplatser. Detta projekt har fokuserat på att ta fram ett koncept för hur hytterna ska transporteras mellan lokalerna på ett så smidigt sätt som möjligt, idag används en lastbilstrailer. Konceptet skulle kunna användas som buffertzon vilket ställde krav på lastutrymmets fuktighet. Dessutom skulle den hytt som lastas först kunna tas ut först. Uppdraget avgränsades till att ta fram ett traktorsläp då dessa ansågs ha få trafikkrav. I början av projektet låg fokus på att skapa en uppfattning av problemet. Detta gjordes genom att följa med och titta på hur problemet hanterades med den befintliga lösningen samt genom att prata med berörda personer. Det konstaterades att det steg som var krångligast var när trucken skulle lyfta hytterna i och ur trailern. I samråd med LSV valdes att titta närmare på en lösning där lastning kunde ske manuellt genom att reglera släpvagnens höjd efter lastplatsens utformning. För att hitta inspiration till detta söktes befintliga höj- och sänkbara släp. Problemet bröts ner i delproblem och flera lösningar försökte hittas. Idéerna utvärderades först enskilt och ett antal koncept valdes ut. Dessa presenterades för de inblandade personerna på företaget och ett gemensamt konceptval gjordes. Därefter bestämdes släpvagnens utseende och funktion mer i detalj. Enklare hållfasthetsberäkningar utfördes i datorprogram och en 3D – modell av släpvagnen skapades. En ritning med viktiga mått och en beskrivande sprängskiss togs fram. Flera företag kontaktades för att få prisuppgifter på släpets olika delar, för de delar där inget pris hittades gjordes uppskattningar. Kostnaderna sammanställdes i en kostnadskalkyl. / Laxå Special Vehicles (LSV) is a company that has a strong partnership with Scania. They modify and build various parts of Scania's trucks, including cabs. Scania has updated the cabs design and LSV has been forced to expand with a new factory in the same area. The new production will require a large area and LSV will get fewer buffer zones. This project has focused on developing a concept for how to transport the cabs between the factories as smoothly as possible, today a trailer is used. The concept would also be used as a buffer zone, which demands that the cargo space humidity is low enough. Another demand was that the first loaded cab is possible to remove first (FIFO). The task was delimited to develop a tractor trailer as these were considered to have few traffic requirements. At the beginning the project focused on understanding the problem. This was done by looking at how the problem was handled today and by talking to persons of interest. The most difficult step was when the cabs were to be loaded by forklift. In consultation with LSV, it was chosen to look into a solution where loading could be done manually, by changing the trailer’s level relative to the cargo loading area. To find inspiration for this, a search for existing lifting and lowering trailers was performed. The big problem was broken into smaller problems and several possible solutions were examined. The ideas were evaluated individually and a number of concepts were selected. These were presented to the company and a final choice was made. Then, the appearance and function of the trailer was determined in more detail. Strength analysis were made in a computer program and a 3D model of the trailer was created. A drawing with important dimensions and an exploded view of the trailer was presented. Several companies were contacted for price information on the trailers parts, for those parts where no price was found an estimation was made. The costs was then summarized.