Browsing by Subject "Automobile"
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Item A Traffic Operations Method for Evaluating Automobile and Bicycle Shared Roadways(2012-07-16) Robertson, James AllanShared roadways are a cost effective method for providing bicycle facilities in areas with limited right-of-way; shared roadways have automobiles and bicycles operating in the same traveled way. However, shared roadways may negatively affect traffic operations and there is limited guidance on appropriate shared roadways implementation. This thesis has three objectives: evaluate the impact of shared roadways on automobile quality of service, compare automobile quality of service to bicycle quality of service on shared roadways, and provide guidance on the implementation of shared roadways. The author hypothesizes that shared roadways should only be implemented when automobile Level of Service (LOS), bicycle LOS, and facility safety are "acceptable." The author accomplishes the objectives by generating data using microsimulation models. The author uses microsimulation model data to evaluate automobile quality of service on shared roadways. In the evaluation of automobile quality of service, the measures of effectiveness are automobile LOS threshold (the maximum automobile flow-rate before a change in automobile LOS) and automobile average travel speed (the average travel time divided by the segment length, a space mean speed). To compare automobile and bicycle quality of service, the author uses the bicycle LOS model in NCHRP Report 616 to generate bicycle LOS thresholds (the maximum automobile flow-rate before a change in bicycle LOS). After generating bicycle LOS thresholds, the author compares the bicycle LOS thresholds to the automobile LOS thresholds. Finally, the author uses the findings of the investigations to provide guidance on the implementation of shared roadways. In this thesis, the author finds automobile quality of service on shared roadways decreases as automobile free-flow speed, automobile volume, and bicycle volume increase. For most conditions, the author finds bicycle quality of service is better than automobile quality of service on shared roadways. Bicycle quality of service is lower than automobile quality of service with increases in unsignalized access points per mile, signalized intersection crossing distance, and heavy vehicle percent. The author provides guidance on the implementation of shared roadways based upon automobile quality of service.Item Automated Vehicle Articulation and Animation: A Maxscript Approach(2011-02-22) Griffin, Christopher CoreyThis thesis presents an efficient, animation production-centric solution to the articulation and animation of computer generated automobiles for creating animations with a high degree of believability. The thesis has two main foci which include an automated and customizable articulation system for automobile models and a vehicle animation system that utilizes minimal simulation techniques. The primary contribution of this thesis is the definition of a computer graphics animation software program that utilizes simulation and key-frame methods for defining vehicle motion. There is an emphasis on maintaining efficiency to prevent long wait times during the animation process and allow for immediate interactivity. The program, when implemented, allows for animation of a vehicle with minimal input and setup. These automated tools could make animating an automobile, or multiple automobiles of varying form and dimensions much more efficient and believable in a film, animation, or game production environment.Item A fundamental approximation in MATLAB of the efficiency of an automotive differential in transmitting rotational kinetic energy(2012-05) Vaughn, James Roy; Matthews, Ronald D.; Bryant, Michael D.The VCOST budgeting tool uses a drive cycle simulator to improve fuel economy predictions for vehicle fleets. This drive cycle simulator needs to predict the efficiency of various components of the vehicle's powertrain including any differentials. Existing differential efficiency models either lack accuracy over the operating conditions considered or require too great an investment. A fundamental model for differential efficiency is a cost-effective solution for predicting the odd behaviors unique to a differential. The differential efficiency model itself combines the torque balance equation and the Navier-Stokes equations with models for gear pair, bearing, and seal efficiencies under a set of appropriate assumptions. Comparison of the model with existing data has shown that observable trends in differential efficiency are reproducible in some cases to within 10% of the accepted efficiency value over a range of torques and speeds that represents the operating conditions of the differential. Though the model is generally an improvement over existing curve fits, the potential exists for further improvement to the accuracy of the model. When the model performs correctly, it represents an immense savings over collecting data with comparable accuracy.