Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"Drawbar"”.
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Experimental Analysis of the Effects of the Variation of Drawbar Pull Test Parameters for Exploration Vehicles on GRC-1 Lunar Soil Simulant
A drawbar pull (DP) test procedure was developed at the NASA Glenn Research Center (GRC) for testing and developing designs for off-road vehicles. The motivation was to develop a procedure that would produce repeatable results and could be replicated by other researchers. While developing the test …
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Experimental Evaluation and Semi-Empirical Modeling of the Tractive Performance of Rigid and Flexible Wheels on Lunar Soil Simulant
… contact length. For each test the normal load, drawbar pull, and driving torque were measured and recorded for further analysis. To measure the effect of the changes in the wheels' parameters on the contact patch under different loads, a pressure pad was embedded below the surface of the Lunar …
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Comparative Study of the Effect of Tread Rubber Compound on Tire Performance on Ice
… the effects of the tread rubber compound on the drawbar pull performance of tires in contact with an ice layer near its melting point. A set of sixteen tires of eight different rubber compounds were considered. The tires were identical in design and tread patterns but have different tread rubber …
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Wheel design optimization for locomotion in granular beds using resistive force theory
… of tests varying the angle of the flaps and the drawbar force the wheel tows. The results indicate a trend toward higher velocities and powers at larger flap angles. Conversely, with larger drawbar forces the trend indicates lower velocities and higher powers. A MATLAB simulation was also created …
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Empirical Analysis of Pneumatic Tire Friction on Ice
… on a tire, providing directly the data for the drawbar pull of said tire, thus supporting the calculation of friction based on this data. This indoor testing apparatus allows for some degree of replication by helping to maintain test conditions and by imposing a desired tire slip; the normal …
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Experimental Investigation of the Tractive Performance of an Instrumented Off Road Tire in a Soft Soil Terrain
… data to analyze several relations, such as the drawbar pull and the sinkage dependency on slip. The data col-lected indicated that, when looking at the effect of individual parameters, by increasing the soil com-paction, the normal load, and by decreasing the inflation pressure will result in a …
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Modelling and prediction of tire-rim slip with finite element analysis
… as terrain type, tire-rim friction coefficient, drawbar load, vertical load, inflation pressure, and longitudinal wheel speed. Two terrain types were used: a high-friction hard surface and a soft SPH soil calibrated to represent upland sandy loam. An additional step was the design and training of …
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Modeling, Design, and Assembly of Spring Tires
… compression testing, rough terrain driving, and drawbar pull testing to assess their performance.
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Terramechanics of Saturated Clays: Assessing Tire Performance Through Experimental and Numerical Approaches
… tools capable of accurately predicting drawbar performance and sinkage are useful for path prediction and navigation without the loss of mobility. This thesis focuses on formulating the physics underlying such predictive tools, particularly in the challenging terrain of saturated clays. …
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Terrain and Vehicle-Terrain Sensing and Estimation in Real-Time for Use in Autonomous Vehicles
… angle can then be used to further obtain the drawbar pull and the tractive effort. The cameras were experimentally tested and validated using the Terramechanics testing rig at the TMVS laboratory at Virgina Tech. Both single pass and multi-pass scenarios were tested and the results analyzed. …
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Terramechanical analysis of rover wheel mobility over simulated Martian terrain at various slip conditions and vertical loads
… loads on the rover wheel increases, values for drawbar force, wheel torque, and sinkage generally increase as well, which are the same trends predicted by the Artemis software package. Supplementary testing will need to be completed for additional slip levels and vertical loads to further …
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Prediction of mobility, handling, and tractive efficiency of wheeled off-road vehicles
… and predicts basic features, such as the drawbar pull, the driving torque and the lateral force, as well as complex behaviors, such as the slip-sinkage phenomenon and the multi-pass effect. The tractive efficiency of different tire-soil configurations is simulated and discussed. To …
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Development of a Tow Capacity Test Device for Small Unmanned Vehicles
Unmanned ground vehicles (UGVs) will increasingly be used for tasks such as retrieving injured soldiers from a battlefield, transporting supplies, and towing other small vehicles and payloads. To date, the unmanned test community has not standardized on an apparatus or test operating procedure …