122 research outputs found
A Simple Hybrid Electric Vehicle Fuel Consumption Model for Transportation Applications
This study presents a simple power-based microscopic hybrid electric vehicle (HEV) fuel consumption model for use in microscopic traffic software and various connected and automated vehicle (CAV) applications, including eco-routing and eco-drive systems. While numerous HEV energy consumption models have been developed, these models are complex and require vehicle engine data deeming them difficult to implement and making them nontransferable. The proposed model was developed using empirical data for a 2010 Toyota Prius—the most popular HEV. The model was then extended to other HEVs thus extending the domain of application of the model. The proposed fuel consumption model estimates the instantaneous fuel consumption rates of an HEV using instantaneous vehicle operational input variables, including the vehicle’s speed, acceleration, and roadway grade, which can be acquired from global positioning system (GPS) equipment or other sensors. The model estimates vehicle fuel consumption rates consistent with empirical data producing an average error of 2.1% for the Toyota Prius and up to 4% for other HEVs demonstrating the applicability and transferability of the model to various HEVs
Can We Model Driver Perceptions? An In-Situ Experiment in Real-World Conditions
ABSTRACTIt is clear that perceptions play a significant role in traveler decisions. Consequently, traveler perceptions are a corner stone in the feasibility of traveler information systems; for traveler information systems are only valuable if the drivers are incapable of accurately acquiring the provided information on their own, and if the provided information is relevant for the drivers' decision criteria. Accuracy of traveler perceptions has been repeatedly researched in public transportation, and has been found to vary according to different reasons. However, in spite of the clear significance of traveler perceptions, minimal effort has been put into modeling it. Almost all travel behavior models are based on traveler experiences, which are assumed to reflect traveler perceptions via the addition of some random error component. This works introduces an alternative approach: instead of adding an error component to represent driver perceptions, it proposes to model driver perceptions. This work is based on a real-world route choice experiment of a sample of 20 drivers who made more than 2,000 real-world route choices. Each of the drivers' experiences, perceptions, and choices were recorded, analyzed and cross examined. The paper demonstrates that: i) driver experiences are different from driver perceptions, ii) driver perceptions explain driver choices better than driver experiences, iii) it is possible to model and predict driver perceptions of travel distance, time and speed
Modeling bike counts in a bike-sharing system considering the effect of weather conditions
The paper develops a method that quantifies the effect of weather conditions
on the prediction of bike station counts in the San Francisco Bay Area Bike
Share System. The Random Forest technique was used to rank the predictors that
were then used to develop a regression model using a guided forward step-wise
regression approach. The Bayesian Information Criterion was used in the
development and comparison of the various prediction models. We demonstrated
that the proposed approach is promising to quantify the effect of various
features on a large BSS and on each station in cases of large networks with big
data. The results show that the time-of-the-day, temperature, and humidity
level (which has not been studied before) are significant count predictors. It
also shows that as weather variables are geographic location dependent and thus
should be quantified before using them in modeling. Further, findings show that
the number of available bikes at station i at time t-1 and time-of-the-day were
the most significant variables in estimating the bike counts at station i.Comment: Published in Case Studies on Transport Policy (Volume 7, Issue 2,
June 2019, Pages 261-268
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