Browsing by Author "Jones, Dwight W."

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    Design and Implementation of a Redress System for Roller Rig
    Jones, Dwight W.; Ahmadian, Mehdi (Virginia Tech, 2022-12-16)
    The Virginia Tech – Federal Railroad Administration Roller Rig at the Center for Vehicle Systems and Safety is a state of the art facility used to evaluate the wheel-rail contact mechanics and dynamics of railway vehicles and track. The Roller Rig consists mainly of an upper wheel and a lower roller that serve to simulate a railway vehicle and track respectively. Upon the completion of testing using the Roller Rig, a section of roughness is created on the surface of the wheel as a product of the two surfaces coming into contact with each other. In order to ensure data accuracy between different tests, the rough surface of the wheel must be smoothed down in between different tests and experiments performed on the Roller Rig. Initially, this process of smoothing the wheel was done completely manually, with the operator fixing a piece of sandpaper around a plastic tube and physically holding it contact while the wheel spins. Quite obviously, this manual process introduces issues of consistency and safety of the user, considering the Roller Rig is a device capable of outputting several hundred pounds of force. Therefore, in order to solve the problems that the manual process introduced, a project that converted the entirely manual process to that of a semi-automatic process of redressing. Therefore, in the Spring of 2021, the first version of the Roller Rig Redresser was constructed and reported on. However, due to the problems that the first version had, it was unable to be used for redressing on a reliable and consistent basis. Therefore, over the Fall 2022 semester, a second version of the Roller Rig Redresser was constructed and reported on, focusing on directly improving the shortcomings of the manual process and the aforementioned first redresser version.
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    Mechanical Design & Fabrication of Redressing System for the VT-FRA Roller Rig
    Jones, Dwight W.; Ahmadian, Mehdi; Molzon, Michael (Virginia Tech, 2022-01-31)
    At the Center for Vehicle Systems and Safety at Virginia Tech, the Virginia Tech – Federal Railroad Administration Roller Rig is a state of the art facility used in evaluating the wheel-rail mechanics and dynamics of railway vehicle and track. Consisting of an upper wheel, a lower roller, and multiple actuators/servos, the Roller Rig is fitted with sensors that measure different parameters from force, rotation speed, and more. However, while the Roller Rig is a fitting device for a multitude of scientific and engineering studies related to railway vehicles, wheel-rail interaction while the Roller Rig is in operation, creates a rough wear band that is visible both to the naked eye, and on the micron level with the use of laser scanners. With the presence of this wear band, before the start of each experiment, a process known as redressing must be performed to smooth the surface of the wheel. This process is necessary to promote data precision and consistency throughout experiments. Previously, this process was done entirely manually, with the individual wrapping various grades of sandpaper around a common PVC pipe and applying pressure while the Roller Rig’s wheel spins. This is done with a total of 5 grades of sandpaper, varying from 40 grit up to 220 grit. As one can imagine, this process is incredibly labor intensive and presents many concerns related to safety, worker productivity, and overall precision and consistency of the redressing process. This paper will look at the development of a device to perform this redressing process in a semi-automatic, hands-off manner. Through initial brainstorming and concept generation to fabrication methods and manufacturing, this paper looks at the different the Roller Rig Redresser project throughout the entire engineering design process.
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    Video Image System Implementation on the Track Crawler Robot
    Jones, Dwight W.; Mehdi, Ahmadian; Molzon, Michael; Larson, Ian (Virginia Tech, 2022-05-04)
    The Track Crawler robot at the Center for Vehicle Systems and Safety, in Blacksburg, Virginia, is a state of the art project that is designed to examine the underbelly of trains while in a dormant state. The idea and motivation for this project comes from scenario that a train would arrive at a station, after completing a journey, and the Track Crawler robot would navigate under the train to examine the systems within to allow engineers to determine if parts of the train require extra maintenance before its next journey. Consequentially, the majority of the Track Crawler project is dependent on the proper function of the robot’s video imaging system. This system allows engineers to have a clear view of the underbelly of the theoretical train, in a space thatis otherwise not accessible to view by the naked human eye. On the current model of the Track Crawler, the robot is fitted with up to 3 GoPro Hero 8 Black Cameras, aligned in a linear fashion, to work as the robot’s video imaging system. One of the major problems with this system, however, is the vibrations the system is put under while the robot is in motion, and effect it has on the quality of videos. Therefore, the scope of this report will be to give the reader an idea of how the problem was identified as well as outlining possible solutions for a new visual imaging system that includes a new standard video camera, an infrared camera, and an adjustable light sensor. All of these proposed additional systems will work to remedy the original problem of maintaining high video quality at high frequency vibrations, and this report will serve as a foundation for implementing a more detailed design in the future.