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Technical Paper

The Successful Personal Air Vehicle: Business Case Risk Reduction

2006-08-30
2006-01-2431
The development of a universal personal air vehicle has been the dream of aeronautical visionaries since before the time of the Wright brothers' first flight. Through fits and starts the modern general aviation market developed both before and after the Second World War. However, the true personal airplane, one that rivals the automobile, has never emerged. There are a multitude of reasons for this; however, it is not possible to identify any single cause as the key component. Instead it is the complex interaction of regulations, market size, and technical and program risk. This paper shows that in the current environment there are few truly technical barriers to the development of a low-cost personal air vehicle. Instead, the market, regulatory, and program issues have come to dominate the problem. This means that the current impediment to the development of personal air vehicles is essentially an issue of finding a means to “close the business case.”
Journal Article

Power-Split HEV Control Strategy Development with Refined Engine Transients

2012-04-16
2012-01-0629
Power-split hybrid-electric vehicles (HEVs) employ two power paths between the internal combustion (IC) engine and the driven wheels routed through gearing and electric machines (EMs) composing an electrically variable transmission (EVT). The EVT allows IC engine control such that rotational speed can be independent of vehicle speed at all times. By breaking the rigid mechanical connection between the IC engine and the driven wheels, the EVT allows the IC engine to operate in the most efficient region of its characteristic brake specific fuel consumption (BSFC) map. If the most efficient IC engine operating point produces more power than is requested by the driver, the excess IC engine power can be stored in the energy storage system (ESS) and used later. Conversely, if the most efficient IC engine operating point does not meet the power request of the driver, the ESS delivers the difference to the wheels through the EMs.
Technical Paper

High-Performance Plug-In Hybrid Electric Vehicle Design Studies and Considerations

2015-04-14
2015-01-1158
This paper presents a detailed design study and associated considerations supporting the development of high-performance plug-in hybrid electric vehicles (PHEVs). Due to increasingly strict governmental regulations and increased consumer demand, automotive manufacturers have been tasked with the reduction of fuel consumption and greenhouse gas (GHG) emissions. PHEV powertrains can provide a needed balance in terms of fuel economy and vehicle performance by exploiting regenerative braking, pure electric vehicle operation, engine load-point shifting, and power-enhancing hybrid traction modes. Thus, properly designed PHEV powertrains can reduce fuel consumption while increasing vehicle utility and performance.
Technical Paper

Development of an Automated Part Loading and Unloading System for a Cylindrical Die Thread Roller

2007-09-17
2007-01-3916
This paper outlines the design of a part transport and loading/unloading automation system for a cylindrical die thread roller, enumerating many of the design decisions encountered. Specifically, a transport tray system is proposed and prototyped as a benchmark for factory automation. Details of an automation system which will interface with the proposed transport tray system are discussed. A gripping system which accommodates a wide variety of fastener head styles is developed to work in conjunction with the tray concept, and prototyped with favorable results.
Technical Paper

Design Optimization of a Plug-In Hybrid Electric Vehicle

2007-04-16
2007-01-1545
A plug-in hybrid electric vehicle (PHEV) design with design parameters electric motor size, engine size, battery capacity, and battery chemistry type, is optimized with minimum cost as a measure of merit. The PHEV is required to meet a fixed set of performance constraints consisting of 0-60 mph acceleration, 50-70 mph acceleration, 0-30 mph acceleration in all electric operation, top speed, grade ability, and all electric range. The optimization is carried out for values of all electric range of 10, 20, and 40 miles. The social and economic impacts of the optimum designs in terms of reduced gasoline consumption and carbon emissions reduction are calculated. Argonne National Laboratory's Powertrain Systems Analysis Toolkit is used to simulate the performance and fuel economy of the PHEV designs. The costs of different PHEV components and the present value of battery replacements over the vehicle's life are used to determine the design's drivetrain cost.
Technical Paper

Control of PHEV and HEV Parallel Powertrains Using a Sequential Linearization Algorithm

2015-04-14
2015-01-1219
Using measurable physical input variables, an implementable control algorithm for parallel architecture plug-in and non-plug-in hybrid electric vehicle (PHEV and HEV) powertrains is presented. The control of the electric drive is based on an algebraic mapping of the accelerator pedal position, the battery state-of-charge (SOC), and the vehicle velocity into a motor controller input torque command. This mapping is developed using a sequential linearization control (SLC) methodology. The internal combustion engine (ICE) control uses a modified accelerator pedal to throttle plate angle using an adjustable gain parameter that, in turn, determines the sustained battery SOC. Searches over an admissible control space or the use of pre-defined look-up tables are thus avoided. Actual on-road results for a Ford Explorer with a through-the-road (TTR) hybrid powertrain using this control methodology are presented.
Technical Paper

Battery Modeling for HEV Simulation Model Development

2001-03-05
2001-01-0960
Battery modeling is of major concern for Hybrid Electric Vehicle (HEV) and Electric vehicle (EV) modeling. The major issue lies in characterizing the battery power output in relation to battery's State of Charge (SOC) in various application conditions. In particular, the challenge is associated with the difficulty that the characteristic parameters of the battery, i.e. the accurate data on the open circuit voltage and the internal resistance are hardly obtainable in practical conditions. In this paper, a battery capacity representation and a practical way of battery modeling is introduced for simulation model development based on the experimental data. A realistic way of battery SOC representation is generated from the battery output data. Empirical formulation is derived from the data to correlate the battery current, voltage output with the battery SOC.
Technical Paper

An Analytic Foundation for the Two-Mode Hybrid-Electric Powertrain with a Comparison to the Single-Mode Toyota Prius THS-II Powertrain

2009-04-20
2009-01-1321
General Motors has introduced a Two-Mode Transmission (2-MT) that provides significant improvements over the Toyota THS-II transmission. These improvements are achieved by employing additional planetaries with clutches and brakes to switch from a Mode-1 to Mode-2 as vehicle speed increases. In addition the 2-MT has four fixed-gear ratios that provide for a purely mechanical energy path from the IC engine to the driven wheels with the electric machines also able to provide additional driving torque. The purpose of this present paper is to extend the methodology in a previous paper [1] to include the 2-MT, thereby presenting an analytic foundation for its operation. The main contribution in this analysis is in the definition of dimensionless separation factors, defined in each mode that govern the power split between the parallel mechanical and electrical energy paths from the IC engine to the driven wheels.
Technical Paper

A Generalized Model for Vehicle Thermodynamic Loss Management and Technology Concept Evaluation

2000-10-10
2000-01-5562
The objective of this paper is to develop a generalized loss management model to account for the usage of thermodynamic work potential in vehicles of any type. The key to accomplishing this is creation of a differential representation for vehicle loss as a function of operating condition. This differential model is then integrated through time to obtain an analytical estimate for total usage (and loss) of work potential consumed by each loss mechanism present during vehicle operation. The end result of this analysis is a better understanding of how the work potential initially present in the fuel, batteries, etc. is partitioned amongst all losses relevant to the vehicle's operation. The loss partitioning estimated from this loss management model can be used in conjunction with cost accounting systems to gain a better understanding of underlying drivers on vehicle manufacturing and operating costs.
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