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Effects of On-Road Conditions on HVAC Noise

Univ. Of Erlangen-Nuremberg-Andreas Logdesser, Stefan Becker
  • Technical Paper
  • 2020-01-1555
To be published on 2020-06-03 by SAE International in United States
Noise inside the passenger cabin is made up of multiple sources. A significant reduction of the major sound sources such as the engine, wind and tire noise helped to improve the comfort for passengers. As a consequence, the HVAC sound (heating, ventilation and air-conditioning) is unmasked as a primary noise source inside the passenger cabin and has to be taken into consideration when designing passenger cabin sound. While HVAC sound is often evaluated at stop, the most common situation of its use is while driving. In case of fresh air as mode of operation, the HVAC system is coupled to the environment through the air intake. Any change in the boundary conditions due to on-road driving events and gusts of wind affects the flow field in the HVAC system and in turn influences HVAC noise. This study investigates the effect of mass flow and pressure fluctuations on the HVAC noise. In a first step, major influences on the HVAC system are identified in an on-road test. For further investigation, the HVAC system is analyzed in…
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Investigation of the Effect of Tire Deformation on Open-Wheel Aerodynamics

Graz University of Technology-Philipp Eder, Cornelia Lex
U.A.S. Graz-Thomas Gerstorfer, Thomas Amhofer
  • Technical Paper
  • 2020-01-0546
To be published on 2020-04-14 by SAE International in United States
This paper introduces a finite element (FE) approach to determine tire deformation and its effect on open-wheeled racecar aerodynamics. In recent literature the tire deformation was measured optically using cameras during wind tunnel testing. Combined loads like accelerat-ing at corner exit are difficult to reproduce in wind tunnels and would require several camer-as to measure the tire deformation. In contrast, an FE approach is capable of determining the tire deformation in combined load states accurately and additionally provides the possibility to vary further parameters, for example, the coefficient of friction. The FE tire model was validated using stiffness measurements, contact patch measurements and steady-state cornering measurements on a flat belt tire test rig. The deformed shape of the FE model was used in a computational fluid dynamics (CFD) simulation. A sensitivity study was created to determine the effect of the tire deformation on aerodynamics for un-loaded, purely vertically loaded and combined vertical, lateral and longitudinal forces. In addition, the influence of these three tire deformations was investigated in a CFD study using a full vehicle…
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Use of Partial Recirculation to Limit Build-Up of Cabin Carbon Dioxide Concentrations to Safe Limits per ASHRAE Standard-62

Calsonic Kansei North America Inc.-Gursaran Mathur
  • Technical Paper
  • 2020-01-1245
To be published on 2020-04-14 by SAE International in United States
Carbon dioxide exhaled by occupants remains within the cabin during operation of HVAC unit in recirculation mode. The CO2 inhaled by the occupants goes into their blood stream that negatively affects occupant’s health. ASHRAE Standard-62 (1999) specifies the safe levels of carbon dioxide in conditioned space for humans. The CO2 concentration limit per ASHRAE is 700 ppm over ambient conditions on a continuous basis. Based on the test data, at worst case scenario (idle condition where body leakage will be a minimal) results in CO2 concentrations of 1601, 2846, 4845 and 6587 ppm respective for 1 to 4 occupants in 30 minutes.Author has also conducted test by imposing ASHRAE standard-62. A controller was programmed for operating the blower unit’s intake door to go from recirculation to OSA mode when the measured carbon dioxide ppm level goes above 1100 ppm. The door stays in OSA mode until the cabin carbon dioxide falls to approximately 500ppm. By imposing these limits, the blower unit’s intake door cycles between 3 minutes to 6.5 minutes with four to one occupants…
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A Co-Simulation Platform for Powertrain Controls Development

Hyundai-Kia America Technical Center Inc.-Shihong Fan, Yong Sun, Jason Hoon Lee, Jinho Ha
  • Technical Paper
  • 2020-01-0265
To be published on 2020-04-14 by SAE International in United States
With the advancement of simulation software development, the efficiency of vehicle and powertrain controls research and development can be significantly improved. Traditionally, during the development of a new control algorithm, dyno or on-road testing is necessary to validate the algorithm. Physical testing is not only costly, but also time consuming. In this study, a virtual platform is developed to reduce the effort of testing. To improve the simulation accuracy, co-simulation of multiple software is suggested as each software specializes in certain area. The Platform includes Matlab Simulink, PTV Vissim, Tass Prescan and AVL Cruise. PTV Vissim is used to provide traffic environment to PreScan. PreScan is used for ego vehicle simulation and visualization. Traffic, signal and road network are synchronized in Vissim and PreScan. Powertrain system is simulated in Cruise. MATALB/Simulink serves as master of this co-simulation, and integrates the different software together. It also includes human driver model and a powertrain control function. An ADAS-ISG (Idle Stop and Go) powertrain control algorithm is implemented in Simulink and tested by using the platform under different…
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Experimental-numerical correlation of a multi-body model for comfort analysis of an heavy truck

CNH Industrial-Andrea Morello, Vladi Nosenzo, Enrica Capitelli
Politecnico di Torino-Enrico Galvagno, Michele Galfrè, Mauro Velardocchia
  • Technical Paper
  • 2020-01-0768
To be published on 2020-04-14 by SAE International in United States
In automotive market, today more than in the past, it is very important to reduce time to market and, mostly, developing costs before the final production start. Ideally, bench and the on-road tests can be replaced by multi-body studies because virtual approach guarantees test conditions very close to reality and it is able to exactly replicate the standard procedures. Approval authorities are starting to look at simulations to release homologation certificates. Therefore, today, it is essential to create very reliable models, able to forecast the vehicle behavior on every road condition (including uneven surfaces). The aim of this study is to build a reliable multi-body model of a heavy commercial vehicle and to correlate experimental and numerical data related to comfort analysis for validation purposes. Experimental results are recorded during tests carried out at different speeds and loading conditions on a Belgian blocks track. Simulation data are obtained reproducing the on-road test conditions in multi-body environment. The virtual vehicle is characterized by rigid and flexible bodies, the tire model used is FTire (Flexible Structure Tire…
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Model-Based Calibration of an Automotive Climate Control System

BMW AG-Gerrit Lassahn, Kang Qiu
TU Munich-Patrick Jahn
  • Technical Paper
  • 2020-01-1253
To be published on 2020-04-14 by SAE International in United States
This paper describes a novel approach for modeling an automotive HVAC unit. The model consists of black-box models trained with experimental data from a self-developed measurement setup. It is capable of predicting the temperature and mass flow of the air entering the vehicle cabin at the various air vents. A combination of temperature and velocity sensors is the basis of the measurement setup. A measurement fault analysis is conducted to validate the accuracy of the measurement system. As the data collection is done under fluctuating ambient conditions, a review of the impact of various ambient conditions on the HVAC unit is performed. Correction models that account for the different ambient conditions incorporate these results. Numerous types of black-box models are compared to identify the best-suited type for this approach. Moreover, the accuracy of the model is validated using test drive data. This validation demonstrates the accuracy of the model of 2 K for temperature predictions. Further studies are recommended to quantify the impact of the model inaccuracies on the model-based calibration process.
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A Gear Shifting Indication Strategy of Eco-driving Vehicle

Jiangsu University-Nannan Hu
Jiangsu University-Ren He
  • Technical Paper
  • 2020-01-0966
To be published on 2020-04-14 by SAE International in United States
The current indication strategy of gear shifting indication system for manual transmission vehicles is developed based on the gear shifting strategy of the automatic transmission. In this paper, the driving data of several automatic transmission and manual transmission vehicles are collected. It is found that the shifting frequency of automatic transmission vehicles is significantly higher than that of manual transmission vehicles, which increases the fatigue of drivers. Aiming at this problem, an interval algorithm of gear shifting indication strategy is proposed based on the fuel consumption rate of engine in this paper. The strategy uses genetic algorithm to process the data of fuel consumption rate, finding the maximum and minimum values in the interval of torque and engine speed, and then the interval algorithm is adopted to transform the search of least fuel consumption value into the seeking of optimal interval to avoid the shifting busyness caused by the sudden change of the data of fuel consumption rate. The model of gear shifting indication strategy is established in Matlab/Simulink. Gear shifting tolerance is defined and…
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An Experimental Methodology for Measuring Resistance Forces of Light-Duty Vehicles under Real-World Conditions and the Impact on Fuel Consumption

Aristotle University of Thessaloniki-Dimitrios Komnos, Leonidas Ntziachristos
European Commission Joint Research-Georgios Fontaras, Jelica Pavlovic, Biagio Ciuffo
  • Technical Paper
  • 2020-01-0383
To be published on 2020-04-14 by SAE International in United States
A vital element of any vehicle-certification test is the use of representative values for the vehicle resistance forces. In most certification procedures, including the WLTP recently adopted by the EU, the latter is achieved mainly through coast down tests. Subsequently, the resistance values measured are used for setting up the chassis-dyno resistances applied during the laboratory measurements. These reference values are obtained under controlled conditions, while a series of corrections are applied to make the test procedure more repeatable and reproducible. In real driving, the actual vehicle road loads are influenced by a series of factors leading to a divergence between the certified fuel consumption values, and the real-world ones. An approach of calculating representative road loads during on-road tests can help to obtain a more unobstructed view of vehicle efficiency and, when needed, confirm the officially declared road loads. This approach is also essential for validating simulations and achieving better estimates of the actual fuel consumption, a requirement introduced by the new policy adopted in the EU. In this study, a series of on-road…
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Hardware-in-the-Loop and Road Testing of RLVW and GLOSA Connected Vehicle Applications

Camp LLC-Jayendra Parikh
Ford Motor Co., Ltd.-Alexander Katriniok
  • Technical Paper
  • 2020-01-1379
To be published on 2020-04-14 by SAE International in United States
This paper presents an evaluation of two different Vehicle to Infrastructure (V2I) applications, namely Red Light Violation Warning (RLVW) and Green Light Optimized Speed Advisory (GLOSA). The evaluation method is to first develop and use Hardware-in-the-Loop (HIL) simulator testing, followed by extension of the HIL testing to road testing using an experimental connected vehicle. The HIL simulator used in the testing is a state-of-the-art simulator that consists of the same hardware like the road side unit and traffic cabinet as is used in real intersections and allows testing of numerous different traffic and intersection geometry and timing scenarios realistically. First, the RLVW V2I algorithm is tested in the HIL simulator and then implemented in an On-Board-Unit (OBU) in our experimental vehicle and tested at real world intersections. This same approach of HIL testing followed by testing in real intersections using our experimental vehicle is later extended to the GLOSA application. The GLOSA application that is tested in this paper has both an optimal speed advisory for passing at the green light and also includes a…
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Experimental Evaluation of Longitudinal Control for Connected and Automated Vehicles through Vehicle-in-the-Loop Testing

Argonne National Laboratory-Miriam Di Russo, Simeon Iliev, Kevin M. Stutenberg, Eric Rask
Wayne State University-Jerry Ku
  • Technical Paper
  • 2020-01-0714
To be published on 2020-04-14 by SAE International in United States
Automated driving functionalities delivered through Advanced Driver Assistance System (ADAS) have been adopted more and more frequently in consumer vehicles. The development and implementation of such functionalities pose new challenges in safety and functional testing and the associated validations, due primarily to their high demands on facility and infrastructure. This paper presents a rather unique Vehicle-in-the-Loop (VIL) test setup and methodology compared those previously reported, by combining the advantages of the hardware-in-the-loop (HIL) and traditional chassis dynamometer test cell in place of on-road testing, with a multi-agent real-time simulator for the rest of test environment. Details associated with applying the proposed VIL for testing adaptive cruise control (ACC), in conjunction with approaches for creating a virtual lead vehicle, as well as results of energy consumption analysis for a 2017 Toyota Prime with stock and improved longitudinal control algorithm, are reported to illustrate the effectiveness of low-infrastructure-demand test setup and the potential in applying the setup and methodology to other ADAS functionalities