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Influence of port water injection on the combustion characteristics and exhaust emissions in a spark-ignition direct-injection engine

Shanghai Jiao Tong Univ-Tianbao Wu, Xuesong Li, Min Xu
Shanghai Jiao Tong Univ.-Yadong Fan
  • Technical Paper
  • 2020-01-0294
To be published on 2020-04-14 by SAE International in United States
It is well known that spark-ignition direct-injection (SIDI) gasoline engines have a huge advantage in fuel economy due to their good anti-knock performance compared to port fuel injection engines. However, higher particle number (PN) emissions associated with fuel impingement make the SIDI engines have additional difficulties to meet the upcoming China VI emission standards. In this study, the port water injection (PWI) techniques on a 1.0-L turbocharged, three cylinder, SIDI engine were investigated. PWI strategies were optimized to quantify port water injection as a means of mitigating the knock and improving the combustion performance by sweeping water-fuel mass ratios and PWI timing at different operating conditions. Measurements indicate that regardless of engine load, PWI induced a worsening of the maximum in-cylinder pressure (P-Max) and cycle-to-cycle variations (IMEPN-COV ) , which mainly due to the effects of water dilution and slower burning velocities. But by the advance of spark timing with knock mitigation, we find that the improvement of combustion phasing finally makes it possible to eliminate fuel enrichment, which bring the potential advantages on the…
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Gear Shift Pattern Optimization for Best Fuel Economy, Performance and Emissions

Chidhanand S
Mahindra & Mahindra Ltd-Lemuel Paulraj, Saravanan Muthiah
  • Technical Paper
  • 2020-01-1280
To be published on 2020-04-14 by SAE International in United States
As the FTP-75 drive cycle does not have a prescribed gear shift pattern, automotive OEMs have the flexibility to design. Conventionally, gear shift pattern was formulated based on trial and error method, typically with 10 to 12 iterations on chassis dynamometer. It was a time consuming (i.e. ~ 3 to 4 months) and expensive process. This approach led to declaring poor fuel economy (FE). A simulation procedure was required to generate a gear shift pattern that gives optimal trade-off amongst conflicting objectives (FE, performance and emissions). As a result, a simulation tool was developed in MATLAB to generate an optimum gear shift pattern. Three different SUV/UV models were used as test vehicles in this study. Chassis dyno testing was conducted, and data was collected using the base and optimized gear shift patterns. Dyno test results with optimized gear shift pattern showed FE improvement of ~ 4 to 5% while retaining the NOx margin well above engineering targets. This labeling FE improvement method did not require any hardware or software changes, thus, involved no additional expense.…
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Integrated Regenerative Braking System and Anti-lock Braking System for Hybrid Electric Vehicles & Battery Electric Vehicles

Ford Motor Company-Yixin Yao, Mark Yamazaki, Yanan Zhao
  • Technical Paper
  • 2020-01-0846
To be published on 2020-04-14 by SAE International in United States
Regenerative braking in hybrid electric vehicles is a critical feature to achieve the maximum fuel economy benefit of hybridization. In order to maximize energy recuperation, it is desired to enable regenerative braking during an Anti-lock Braking System (ABS) event. For certain driveline configurations with a single electric motor connected to the axle shaft through an open differential, it has been observed that the regenerative braking torque can increase the wheel slip during the ABS operation, and significantly impact vehicle dynamics. This negative effect introduced by regen braking during ABS control may also lead to hardware failures, such as breaking a drive shaft. This paper describes development of an integrated regenerative braking and ABS control for hybrid and electric drive vehicles, referred to as RBS-ABS Event Control. This control is intended for drivelines containing a single electric motor connected to the axle shaft through an open differential. The design objectives are to recuperate the maximum amount of kinetic energy during an ABS event, and to provide no degraded anti-lock control behavior as seen in vehicles with…
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Development of New Hybrid Transaxle for Mid-Size Sports Utility Vehicles

Toyota Motor Corporation-Seitaro Nobuyasu, Shigetsugu Iwata, Masabumi Nishigaya, Yoshiteru Hagino, Masatoshi Ito, Hiroshi Aihara
  • Technical Paper
  • 2020-01-0850
To be published on 2020-04-14 by SAE International in United States
Recently, automotive industries are active to develop electric in response to the energy conservation and environment problems. We developed the new hybrid transaxle for Mid-Size SUV to improve fuel efficiency and power performance. The transaxle was developed based on the new development strategy TNGA (Toyota New Global Architecture). By adopting technologies for transaxle overall length shortening, installation in same width of Mid-Size sedan engine compartment have been realized while improving the motor output. This paper will explain technologies about new motor structure and new mount structure for overall length shortening, and furthermore, noise reduction toward the mount structure.
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Real-Time Embedded Models for Simulation and Control of Clean and Fuel-Efficient Heavy-Duty Diesel Engines

Daimler Trucks North America-Marc Allain, Siddharth Mahesh
University of Michigan-Saravanan Duraiarasan, Rasoul Salehi, Fucong Wang, Anna Stefanopoulou
  • Technical Paper
  • 2020-01-0257
To be published on 2020-04-14 by SAE International in United States
The ever increasing demand for fuel economy and stringent emission norms drives researchers to continuously innovate and improve engine modes to implement adaptive algorithms, where the engine states are continuously monitored and the control variables are manipulated to operate the engine at the most efficient regime. This paper presents a virtual engine developed by modeling a modern diesel engine and aftertreatment which can be used in real-time on a control unit to predict critical diesel engine variables such as fuel consumption and feed gas conditions including emissions, flow and temperature. A physics-based approach is followed in order to capture vital transient airpath and emission dynamics encountered during real driving condition. A minimal realization of the airpath model is coupled with a cycle averaged NOx emissions predictor to estimate transient feed gas NOx during steady state and transient conditions. The complete airpath and NOx emission model was implemented on a rapid prototyping controller and experimentally validated over steady state and transient emission cycles. The overall performance of the reduced order model was comparable to that of…
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Evaluating the Performance of a Conventional and Hybrid Bus operating on Diesel and B20 Fuel for Emissions and Fuel Economy

U.S. Environmental Protection Agency-Scott Ludlam
US Environmental Protection Agency-Matthew Brusstar
  • Technical Paper
  • 2020-01-1351
To be published on 2020-04-14 by SAE International in United States
With ongoing concerns about the elevated levels of ambient air pollution in urban areas and the contribution from heavy-duty diesel vehicles, hybrid electric buses are considered as a potential solution as they are perceived to be less polluting and more fuel-efficient than their conventional engine counterparts. However, recent studies have shown that real-world emissions may be substantially higher than those measured in the laboratory, mainly due to operating conditions that are not fully accounted for in dynamometer test cycles. At the U.S. EPA National Fuel and Vehicle Emissions Laboratory (NVFEL), the in-use criteria emissions and energy efficiency of heavy-duty class 8 vehicles (up to 80,000 lbs) may be evaluated under controlled conditions in the heavy-duty chassis dynamometer test. The present study evaluated the performance of a conventional bus and hybrid bus for emissions and fuel economy under representative test cycles (including cold start and hot start conditions) with Diesel (#2) and Biodiesel (B20) fuel. The conventional bus was equipped with a Cummins ISL 8.3L engine and a Diesel Particulate Filter (DPF) and Diesel Oxidation Catalyst…
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Using Transmission Data to Isolate Individual Losses in Coastdown Road Load Coefficients

US Environmental Protection Agency-Andrew Moskalik
  • Technical Paper
  • 2020-01-1064
To be published on 2020-04-14 by SAE International in United States
As part of the U.S. Environmental Protection Agency’s continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, multiple transmissions have been benchmarked to determine their efficiency during operation. The benchmarking included a modified “coastdown test,” with the transmission on an engine dynamometer, to measure the transmission output drag as a function of speed while in neutral. The transmission drag data can be represented in quadratic form, similar to that used for vehicle coastdown test results, as F0 + F1V + F2V2, where V is the vehicle velocity. When evaluating the transmission test data, the relationships among the three coefficients found to be highly predictable, and in some cases the magnitude of the coefficients were quite large. Additionally, for some tested transmissions the deviation between the quadratic regression and the measured drag at individual velocities can be significant. To evaluate the effect of transmission losses in vehicle coastdown tests, the coastdown and dynamometer coefficients were pulled from the EPA’s published “Data on Cars used for Testing Fuel Economy” for an entire…
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Cooperative Mandatory Lane Change for Connected Vehicles on Signalized Intersection Roads

Clemson Univ-Zhiyuan Du, Bin Xu, Pierluigi Pisu
  • Technical Paper
  • 2020-01-0889
To be published on 2020-04-14 by SAE International in United States
This paper presents a hierarchical control architecture to coordinate a group of connected vehicles on signalized intersection roads, where the vehicles are allowed change lane to follow a prescribed path. The hierarchical control strategy consists of two levels of controllers. The higher level controller acts as a centralized controller, while the lower level controller implemented in each individual car is designed as decentralized controller. In the hierarchical control architecture, the centralized intersection controller estimates the target velocity for each approaching connected vehicle to avoid red light stop based on the signal phase and timing (SPAT) information. Each connected vehicle as a decentralized controller utilizes Model Predictive Control (MPC) to track the target velocity in a fuel efficient manner. The main objective is this paper is to consider mandatory lane changing. As in the realistic scenarios, vehicles are not necessary required to drive in single lane. More specifically, they more likely change their lanes prior to signals. Hence, the vehicle decentralized controllers are prepared to cooperate with the vehicle which has mandatory lane change request (host…
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Simplified Approach to Model a HEV/PHEV/Battery Vehicle Cooling System in 1D and validating using DFSS methodology

Detroit Engineered Products (DEP) Inc-Toukir Islam
FCA Engineering India Pvt Ltd-AMIT KUMAR, VAIBHAV PATIL, Dhananjay Autade, Kamalakannan J
  • Technical Paper
  • 2020-01-1386
To be published on 2020-04-14 by SAE International in United States
ABSTRACT Improving fuel economy and to satisfy more restrictive emission legislation the Vehicle electrification becomes more important one. Compared to the combustion engine a Hybrid electric vehicles / Plug-in hybrid electric vehicles will use energy from the grid to recharge their high voltage battery and this is converted with much higher efficiency, and less CO2 emission so they will have a significant role in the present transition from conventional to electric vehicles. The addition of new components, such as power electronics, electric machine and high voltage battery, increases the maximum torque available and the energy stored on-board, but increases the weight as well. In addition, although they have really high efficiency, they produce a significant amount of heat that has to be removed. Another thermal management issue in PHEV and BEV is cabin heating, since the engine heat is not available. To guarantee system efficiency and reliability, a completely new thermal management layout has to be designed. The time and cost spent on a real time model of new cooling system will be more which…
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Vehicle Velocity Prediction Using Artificial Neural Network and Effect of Real World Signals on Prediction Window.

CEAS Western Michigan University-Alvis Fong
Colorado State Univ-Thomas Bradley
  • Technical Paper
  • 2020-01-0729
To be published on 2020-04-14 by SAE International in United States
Prediction of vehicle velocity is important since it can realize improvements in the fuel economy/energy efficiency, drivability and safety. Velocity prediction has been addressed in many publications. Several references considered deterministic and stochastic approaches such as Markov chain, autoregressive models, and artificial neural networks. There are numerous new sensor and signal technologies like vehicle-to-vehicle and vehicle-to-infrastructure communication that can be used to obtain inclusive datasets. Using these inclusive datasets of sensors in deep neural networks, high accuracy velocity predictions can be achieved. This research builds upon previous findings that Long Short-Term Memory (LSTM) deep neural networks provide the highest velocity prediction fidelity. We developed LSTM deep neural network which uses different groups of datasets collected in Fort Collins. Synchronous data was gathered using a test vehicle equipped with sensors to measure ego vehicle position and velocity, ADAS-derived near-neighbor relative position and velocity, and infrastructure-level transit time and signal phase and timing. Effect of different group of datasets on forward velocity prediction window of 10, 15, 20 and 30 seconds is studied. Developed algorithm is tested…