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The winter of 2013-2014 provided an opportunity to operate off-road vehicles in cold weather for extended time as part of a vehicle/tier 4 diesel engine validation program. An unexpected area of study was the performance of high efficiency, on engine, fuel filters during continuous vehicle operation in cold weather. During the program we observed unexpected premature fuel filter plugging as indicated by an increase in pressure drop across the filter while in service. Field and laboratory testing was completed at John Deere and Donaldson to understand the cause of filter plugging. Although conditions were found where winter fuel additives could cause plugging of high efficiency filters, premature filter plugging occurred even when testing with #1 diesel fuel. This fuel contained no additives and was used at temperatures well above its cloud point.

This paper gives a history of simulation of commercial vehicles, starting with the early models and progressing to today's multibody models. This is followed by a discussion of the key questions faced by simulators. Finally, the paper presents a new method to postprocess results through videoanimation.

Particle Swarm and the Genetic Algorithm were coupled to optimize multiple performance metrics for the combustion of neat biodiesel in a turbocharged, four cylinder, John Deere engine operating under constant partial load. The enhanced algorithm was used with five inputs including EGR, injection pressure, and the timing/distribution of fuel between a pilot and main injection. A merit function was defined and used to minimize five output parameters including CO, NOx, PM, HC and fuel consumption simultaneously. The combination of PSO and GA yielded convergence to a Pareto regime without the need for excessive engine runs. Results along the Pareto front illustrate the tradeoff between NOx and particulate matter seen in the literature.

This paper presents an analytical study of the performance improvements that can be obtained at both high and low speed using multiple steered axles on heavy articulated trucks. At high speed, rollover usually represents a worst case scenario. Therefore we have chosen to evaluate possible steering designs based on their ability to reduce lateral acceleration of the semitrailer center of gravity. This is in contrast to passenger cars where four-wheel steering has typically been evaluated based on measures that were thought to be related to driver acceptance. This paper also investigates the effects of steering rear tractor axles on the low-speed maneuverability of the vehicle. Steering algorithms for the rear tractor tires were evaluated using frequency response and simulation of an obstacle avoidance maneuver. Results indicate that at high speeds considerable reductions in trailer lateral acceleration can be obtained during transient maneuvers.

It is common to develop extensive dynamic models for new equipment early in the design stage. While dynamic characteristics are often determined from impulse, step, and sinusoidal inputs to the models, the actual response of the equipment will be a response to inputs made by the human using control levers, knobs and switches. The work described here is the use of a robot manipulator that allows the human to provide natural motion and force inputs to the simulated dynamic system and to use the response to evaluate the performance of the system and controls. A heavy lift assist device is used as the test system here, where an operator grasps handles attached to the lifting jaws, and uses a large partially powered mechanism to provide load support. The kinematic and dynamic model of this system are derived and programmed to provide the expected system output in response to human motion and force inputs.