scholarly journals A Comparative Study of Different Objectives Functions for the Minimal Fuel Drive Cycle Optimization in Autonomous Vehicles

Author(s):  
Niket Prakash ◽  
Youngki Kim ◽  
Anna G. Stefaopoulou

With the advent of self-driving autonomous vehicles, vehicle controllers are free to drive their own velocities. This feature can be exploited to drive an optimal velocity trajectory that minimizes fuel consumption. Two typical approaches to drive cycle optimization are velocity smoothing and tractive energy minimization. The former reduces accelerations and decelerations, and hence, it does not require information of vehicle parameters and resistance forces. On the other hand, the latter reduces tractive energy demand at the wheels of a vehicle. In this work, utilizing an experimentally validated full vehicle simulation software, we show that for conventional gasoline vehicles the lower energy velocity trajectory can consume as much fuel as the velocity smoothing case. This implies that the easily implementable, vehicle agnostic velocity smoothing optimization can be used for velocity optimization rather than the nonlinear tractive energy minimization, which results in a pulse-and-glide trajectory.

2018 ◽  
Vol 164 ◽  
pp. 01038
Author(s):  
Ridho Hantoro ◽  
Cahyun Budiono ◽  
Ronald Kipkoech Ketter ◽  
Nyoman Ade Satwika

Over 70 000 000 people in Indonesia have no access to electricity. This study was carried out in Bawean Islands which are located in the Java Sea about 150 km North of Surabaya, the headquarters of East Java. The study to determine the energy services available in the Bawean Island was done through interviewing a random sample of 72 households in two villages namely Komalasa and Lebak. Based on the average monthly electricity consumption of the sampled households connected to the grid, a hybrid renewable energy based electrical supply system was designed for Gili Timur Island, one of the satellite islands around Bawean Island. The system was designed with the aid of a time step simulation software used to design and analyze hybrid power systems. A sensitivity analysis was also carried out on the optimum system to study the effects of variation in some of the system variables. HOMER suggests that for the expected peak load of 131 kW, an optimum system will consist of 150 kW from PV array, two wind turbines each rated 10 kW, a 75 kW diesel generator and batteries for storage.


Author(s):  
Amanda Saunders ◽  
Darris White ◽  
Marc Compere

Abstract BAJA SAE is an engineering competition that challenges teams to design single-seat all-terrain vehicles that participate in a vast number of events, predominately on soft soils. Efficient performance in the events depends on the traction forces, which are dependent on the mechanical properties of the soil. To accurately model vehicle performance for each event, a model of the tire traction performance is required, and the tire model must be incorporated with a vehicle dynamics simulation. The traction forces at the soil-tire interface can be estimated using the Bekker-Wong stress integration method. However, commercially available vehicle dynamics simulation software, with a focus on on-road vehicles, does not utilize Bekker-Wong parameters. The Pacejka Magic Tire (MT) Formula is a common method for characterizing tire behavior for on-road vehicles. The parameters for the Pacejka MT Formula are usually produced by curve fitting measured tire data. The lack of available measured off-road tire data, as well as the additional variables for off-road tire performance (e.g. soil mechanics), make it difficult for BAJA SAE teams to simulate vehicle performance using commercial vehicle simulation tools. This paper discusses the process and results for estimating traction performance using the Bekker-Wong stress integration method for soft soils and then deriving the Pacejka coefficients based on the Bekker-Wong method. The process will enable teams to use the Pacejka Magic Tire Formula coefficients for simulating vehicle performance for BAJA SAE events, such as the hill climb, (off-road) land maneuverability, tractor pull, etc.


2020 ◽  
Vol 12 (24) ◽  
pp. 10476 ◽  
Author(s):  
Demin Nalic ◽  
Aleksa Pandurevic ◽  
Arno Eichberger ◽  
Branko Rogic

The increasingly used approach of combining different simulation softwares in testing of automated driving systems (ADSs) increases the need for potential and convenient software designs. Recently developed co-simulation platforms (CSPs) provide the possibility to cover the high demand for testing kilometers for ADSs by combining vehicle simulation software (VSS) with traffic flow simulation software (TFSS) environments. The emphasis on the demand for testing kilometers is not enough to choose a suitable CSP. The complexity levels of the vehicle, object, sensors, and environment models used are essential for valid and representative simulation results. Choosing a suitable CSP raises the question of how the test procedures should be defined and constructed and what the relevant test scenarios are. Parameters of the ADS, environments, objects, and sensors in the VSS, as well as traffic parameters in the TFSS, can be used to define and generate test scenarios. In order to generate a large number of scenarios in a systematic and automated way, suitable and appropriate software designs are required. In this paper, we present a software design for a CSP based on the Model–View–Controller (MVC) design pattern as well as an implementation of a complex CSP for virtual testing of ADSs. Based on this design, an implementation of a CSP is presented using the VSS from IPG Automotive (CarMaker) and the TFSS from the PTV Group (Vissim). The results showed that the presented CSP design and the implementation of the co-simulation can be used to generate relevant scenarios for testing of ADSs.


2020 ◽  
Vol 7 ◽  
Author(s):  
Tom W. Bell ◽  
Nick J. Nidzieko ◽  
David A. Siegel ◽  
Robert J. Miller ◽  
Kyle C. Cavanaugh ◽  
...  

The emerging sector of offshore kelp aquaculture represents an opportunity to produce biofuel feedstock to help meet growing energy demand. Giant kelp represents an attractive aquaculture crop due to its rapid growth and production, however precision farming over large scales is required to make this crop economically viable. These demands necessitate high frequency monitoring to ensure outplant success, maximum production, and optimum quality of harvested biomass, while the long distance from shore and large necessary scales of production makes in person monitoring impractical. Remote sensing offers a practical monitoring solution and nascent imaging technologies could be leveraged to provide daily products of the kelp canopy and subsurface structures over unprecedented spatial scales. Here, we evaluate the efficacy of remote sensing from satellites and aerial and underwater autonomous vehicles as potential monitoring platforms for offshore kelp aquaculture farms. Decadal-scale analyses of the Southern California Bight showed that high offshore summertime cloud cover restricts the ability of satellite sensors to provide high frequency direct monitoring of these farms. By contrast, daily monitoring of offshore farms using sensors mounted to aerial and underwater drones seems promising. Small Unoccupied Aircraft Systems (sUAS) carrying lightweight optical sensors can provide estimates of canopy area, density, and tissue nitrogen content on the time and space scales necessary for observing changes in this highly dynamic species. Underwater color imagery can be rapidly classified using deep learning models to identify kelp outplants on a longline farm and high acoustic returns of kelp pneumatocysts from side scan sonar imagery signal an ability to monitor the subsurface development of kelp fronds. Current sensing technologies can be used to develop additional machine learning and spectral algorithms to monitor outplant health and canopy macromolecular content, however future developments in vehicle and infrastructure technologies are necessary to reduce costs and transcend operational limitations for continuous deployment in an offshore setting.


2018 ◽  
Vol 196 ◽  
pp. 02029 ◽  
Author(s):  
Peter Juras ◽  
Daniela Jurasova

Scientific research in the area of building simulations has a great potential and it is continuously developing and advancing. Computer simulations are helpful in many areas of Civil Engineering, such as energy demand, moisture transport, thermal comfort, ventilation etc. Climate data measured by experimental weather station are analyzed in this article. Weather station is located within the University campus and data recorded with a short are used in a non-steady heat-air-moisture simulation. Climate parameters differences caused by the various averaging periods are shown. This differences are also analyzed in term of outdoor surface temperatures calculated with WUFI Pro simulation software.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Jorge de-J. Lozoya-Santos ◽  
Damián Cervantes-Muñoz ◽  
Juan Carlos Tudón-Martínez ◽  
Ricardo A. Ramírez-Mendoza

The topic of this paper is the analysis of a control system for a semiactive rear suspension in an off-road two-wheeled vehicle. Several control methods are studied, as well as the recently proposed Frequency Estimation Based (FEB) algorithm. The motorcycle dynamics, as well as the passive, and semiactive dampers, and the algorithm controlled shock absorber models are loaded into BikeSim, a professional two-wheeled vehicle simulation software, and tested in several road conditions. The results show a detailed comparison of the theoretical performance of the different control approaches in a novel environment for semiactive dampers.


2011 ◽  
Vol 130-134 ◽  
pp. 2211-2215
Author(s):  
Bing Zhan Zhang ◽  
Han Zhao ◽  
An Dong Yin

Control strategy is the most important issue in the Plug-in Hybrid electric vehicles (PHEV) design, which has two modes: charge depleting mode (CD) and charge sustaining mode (CS). The different control strategies in depleting mode will have a great influence on PHEV dynamic performance and fuel economy. The engine optimal torque control strategy was proposed in the paper. The vehicle simulation model in Powertrain Systems Analysis Toolkit (PSAT) was adopted to evaluate the proposed control strategy. The aggressive highway drive cycle Artemis_hwy and a random drive cycle generated by Markov Process were used. The simulation results indicate the proposed control strategy has great improvement in fuel economy.


Sign in / Sign up

Export Citation Format

Share Document