Showing papers by "Giorgio Rizzoni published in 2006"

An Adaptive Algorithm for Hybrid Electric Vehicle Energy Management Based on Driving Pattern Recognition

Abstract: In this paper we present a novel adaptation method for the Adaptive Equivalent fuel Consumption Minimization Strategy (A-ECMS). The approach is based on Driving Pattern Recognition (DPR). The Equivalent (fuel) Consumption Minimization Strategy (ECMS) method provides real-time suboptimal energy management decisions by minimizing the "equivalent" fuel consumption of a hybrid-electric vehicle. The equivalent fuel consumption is a combination of the actual fuel consumption and electrical energy use, and an equivalence factor is used to convert electrical power used into an equivalent chemical fuel quantity. In this research, a driving pattern recognition method is used to obtain better estimation of the equivalence factor under different driving conditions. A time window of past driving conditions is analyzed periodically and recognized as one of the Representative Driving Patterns (RDPs). Periodically updating the control parameter according to the driving conditions yields more precise estimation of the equivalent fuel consumption cost, thus providing better fuel economy. Besides minimizing the instantaneous equivalent fuel consumption, the battery State of Charge (SOC) management is also maintained by using a PI controller to keep the SOC around a nominal value. The primary improvement of the proposed A-ECMS over other algorithms with similar objectives is that it does not require the knowledge of future driving cycles and has a low computational burden. Results obtained in this research show that the driving conditions can be successfully recognized and good performance can be achieved in various driving conditions while sustaining battery SOC within desired limits.Copyright © 2006 by ASME

Injection diagnosis through common-rail pressure measurement

Abstract: Modern diesel common-rail injection systems supply fuel from a high-pressure vessel. The injection event causes an instantaneous drop in the rail pressure, as the stored mass is diminished. Pressure variations are also affected by the dynamics of the high-pressure pump that supplies fuel to the rail to compensate for the emptying process due to the injection. This paper proposes the possibility of diagnosing the injection process from measurement of the rail pressure. Different data treatment techniques are explored and evaluated in this paper to propose an effective method for the diagnosis of common-rail injection systems.

Development of a terrain severity measurement system utilizing optical lasers

Abstract: A terrain severity measurement system utilizing non-contact optical scanning laser technologies employed in on-road profiling has been developed to make detailed measurements of the relative smoothness of all types of terrain from paved roads to extreme off-road conditions. The objectives included operation in all climatic conditions, simplified operation, and rapid availability of data. Accelerometers and inclinometers are used to measure laser sensor movement in order to eliminate measurement errors due to vehicle pitch and roll. A GPS receiver is used to correlate terrain profile information to position and elevation data. The end result is an accurate description of the longitudinal and lateral terrain profile that can be used to characterize the terrain and within vehicle modeling and simulation programs.

Model-Based Fault Detection and Isolation in Automotive Electrical Systems

Abstract: This paper deals with the design and validation, through simulation in a Matlab/Simulink and SABER environment, of model-based diagnostic algorithms for an automotive electric power generation system (EPGS). The EPGS includes alternator with rectifier, a battery, and a voltage regulator. The mathematic models of these subsystems, based on the physics of the processes involved, consist of time-varying nonlinear ODEs. The diagnostic problem focuses on the detection and isolation of a specific set of alternator faults, including belt slipping, rectifier fault and voltage regulator fault. An in-depth analysis of the models is conducted in order to understand the effects of different failure modes on system performance; subsequently, an equivalent input-output model of the alternator is formulated and parameterized. The equivalent model permits considerable simplification of the algorithms. The proposed diagnostic approach is based on the generation of residuals obtained using system models and comparing the predicted and measured value of selected variables, including alternator output current, field voltage, battery current, battery voltage and battery temperature. This paper presents the models, diagnostic algorithms and simulation results.Copyright © 2006 by ASME

The Development of a Terrain Severity Measurement System

Abstract: The measurement of road profiles is useful for many purposes, from the determination of road conditions, to terrain mapping, and so on. There are systems in which the profile measurement is taken utilizing of non-contact laser scanning technologies. In such systems, the measurements are relative and are referred to a moving reference frame. These measurements require the knowledge of the moving reference frame, which can be extracted from inertial measurements. Typically, each of these sensors is provided with an accelerometer, and the vertical distance travelled by each sensor is calculated by integrating this accelerometer signal twice. In this work, the errors associated with the measurement of the terrain profile are analyzed in order to identify the main causes of measurement error as well as the overall accuracy of the terrain severity measurement system.© 2006 ASME

Aging Characterization of Nickel: Metal Hydride Batteries Using Electrochemical Impedance Spectroscopy

Abstract: During a battery's lifetime, its performance slowly deteriorates because of the degradation of its electrochemical constituents. This degradation produces undesirable effects that include the loss of rated capacity, faster temperature rise during operation, less charge acceptance, higher internal resistance, lower voltage, and more frequent self-discharge. The most drastic effect is the loss of capacity. This paper presents a method to quantify the electrochemical process behind the aging of a battery by using electrochemical impedance spectroscopy as a tool to measure the change in battery parameters. While classical methods would relate battery age to impedance measurements at one specific frequency, this method measures the battery impedance at different frequencies and evaluates the variation in the frequency response spectrum with respect to battery age. The variation of the impedance spectrum from one experiment to another allows to get a better characterization of the aging process.Copyright © 2006 by ASME

Toward a framework for the hybrid control of a multi-mode hybrid-electric driveline

Abstract: A supervisory control strategy is designed to address fuel minimization, battery state-of-charge control and drivability issues for a power-split, hybrid-electric vehicle. The energy management strategy relies solely on the current vehicle conditions and it does not require knowledge of the entire driving cycle a priori. While the state-of-charge control is largely integrated into the energy optimization strategy, the drivability control is treated separately but in such a way that the instantaneous power demand requested by the driver is still satisfied. The energy management strategy is tested on a quasi-static simulation model of the Ohio State University Challenge-X competition vehicle (a hybridized version of the GM Equinox). Simulation results show a remarkable improvement in fuel savings over the non-hybrid base vehicle.

Experimental Validation for Control-Oriented Modeling of Multi-Cylinder HCCI Diesel Engines

Abstract: Homogeneous Charge Compression Ignition (HCCI) is a combustion process based on a lean, homogeneous, premixed charge reacting and burning uniformly throughout the mixture volume. This principle leads to a consistent decrease in NOx and PM emissions, while the combustion efficiency remains comparable to traditional Compression Ignition Direct Injection (CIDI) engines at low and mid-load operations. However, understanding and controlling the combustion process is still extremely difficult, as well as finding a proper method for the fuel introduction. A viable method consists of premixing the charge by applying a proper fuel atomization device in the intake port, thus decoupling the HCCI mixture formation from the traditional in-cylinder injection. This avoids the traditional drawbacks associated to external Diesel mixture preparation, such as high intake heating, low compression ratio, wall wetting, and soot formation. The system, previously developed and tested on a single-cylinder engine, has been successfully applied to multi-cylinder Diesel engine for automotive applications. Building on previous modeling and experimental work, the paper reports a detailed experimental analysis of HCCI combustion with external mixture formation. In the considered testing setup, the fuel atomizer has been applied to a four-cylinder turbo-charged Common Rail Diesel engine equipped with a cooled EGR system. In order to extend the knowledge on the process and to provide a large base of data for the identification of Control-Oriented Models, Diesel-fueled HCCI combustion has been characterized over different values of loads, EGR dilution and boost pressures. The data collected were then used for the validation of a HCCI Diesel engine model that was previously built for steady state and transient simulation and for control purposes. The experimental results obtained, especially considering the emission levels and efficiency, suggest that the technology developed for external mixture formation is a feasible upgrade for automotive Diesel engines without introducing additional design efforts or constraints on the DI combustion and injection system.Copyright © 2006 by ASME

Evaluation of powertrain solutions for Future Tactical Truck Vehicle Systems

Abstract: The article presents the results of a large scale design space exploration for the hybridization of two off-road vehicles, part of the Future Tactical Truck System (FTTS) family: Maneuver Sustainment Vehicle (MSV) and Utility Vehicle (UV). Series hybrid architectures are examined. The objective of the paper is to illustrate a novel design methodology that allows for the choice of the optimal values of several vehicle parameters. The methodology consists in an extensive design space exploration, which involves running a large number of computer simulations with systematically varied vehicle design parameters, where each variant is paced through several different mission profiles, and multiple attributes of performance are measured. The resulting designs are filtered to choose the design tradeoffs that better satisfy the performance and fuel economy requirements. At the end, few promising vehicle configuration designs will be selected that will need additional detailed investigation including neglected metrics like ride and drivability. Several powertrain architectures have been simulated. The design parameters include the number of axles in the vehicle (2 or 3), the number of electric motors per axle (1 or 2), the type of internal combustion engine, the type and quantity of energy storage system devices (batteries, electrochemical capacitors or both together). An energy management control strategy has also been developed to provide efficiency and performance. The control parameters are tunable and have been included into the design space exploration. The results show that the internal combustion engine and the energy storage system devices are extremely important for the vehicle performance.

Opportunities for Thermoelectric Energy Conversion in Hybrid Vehicles

Abstract: Much analysis has been performed on the application of thermoelectrics in automobiles, but the low efficiency of the materials has so far limited their use. As a result, little has been done in the physical design of how to most efficiently utilize thermoelectrics in a vehicle's energy system. However, much progress has been and continues to be made in the field of thermoelectric materials. Developments in the areas of nanostructured materials have produced materials with double the efficiency of current commercially available materials. This, coupled with a growing need for the reduced consumption of fossil fuels and production of greenhouse gases, has generated renewed interest in the application of thermoelectrics in automotive systems. Hybrid-electric vehicle (HEV) designs have provided significant improvements in fuel efficiency and continue to evolve. This modified energy management strategy introduces new components and energy distributions which force traditional designs to be reconsidered. For example, the temperature and quantity of thermal energy transferred through the exhaust and radiator are lowered. Also, the IC engine may not be run continuously, creating difficulties in maintaining temperature in the catalytic converter, powering belt-driven accessories, and regulating cabin temperature. This contributes to an increased demand for electrical energy. Finally, the power electronics are typically liquid cooled (order of 60-65 °C) and the high voltage battery packs must be kept cool (typically below 45 °C) to maximize their life. A detailed computer model which captures the details of the energy transfers in HEV's, including thermal loads will be used to assess the unique thermal requirements of hybrid vehicles under average engine loads. Based on these requirements, specific thermal energy management strategies will be proposed. These modified systems will be added to the computer model in order to evaluate their potential using currently available thermoelectrics materials. Finally, the preferred thermal energy management system will be selected as the basis for future design optimization.Copyright © 2006 by ASME

Hybrid-Electric Powertrain Design Evaluation for Future Tactical Truck Vehicle Systems

Abstract: The article presents the results of a large-scale design space exploration for two vehicles part of the Future Tactical Truck System (FTTS) family. A multi-objective optimization tool is presented, that allows designers to make appropriate trade-offs amongst different vehicle characteristics, on the basis of simulations run varying vehicle parameters over a broad range of values. Several powertrain architectures were taken into consideration for the Maneuver Sustainment Vehicle (MSV) and Utility Vehicle (UV). The architecture alternatives include the number of axles in the vehicle (2 or 3), the number of electric motors per axle (1 or 2), the type of internal combustion engine, the type and quantity of devices for energy storage (batteries, electrochemical capacitors or both together). A control strategy for energy management was developed to provide efficiency and performance. The control parameters are tunable and have been included into the design space exploration.Copyright © 2006 by ASME

Concept design of a new generation military vehicle

Abstract: This paper presents the development of an advanced concept for a next generation military vehicle based on state of the art technologies. The vehicle's platform will be directly suitable for high mobility applications for instance: Special Forces missions, Marine reconnaissance missions, and commercial racing in events such as Bajas and the Paris - Dakar. The platform will be a 10000 -14000 lbs high-speed multi-purpose vehicle, designed for extreme off-road operation. A completely new suspension concept is expected to be developed and the new vehicle topology will accommodate a new generation hybrid-electric power train. The dynamic performance targets are 125 mph off-road and 0-60 in 7 seconds. The concept design will focus also on survivability mainly through the use of a new vehicle topology (herein referred to as "island") specifically designed to enhance crew protection. The "island" topology consists in locating the powertrain and other vehicle equipment and subsystems around the crew compartment. Thus, even in the event of an external shield penetration the crew compartment remains protected by the surrounding equipment which serves in an additional role as a secondary shield. The paper presents vehicle specifications, performance capabilities, simulation models and virtual models of the vehicle.

Rejection of harmonic sensor disturbances in passive systems, and applications to attitude control

Abstract: We consider the problem of asymptotic stabilization of nonlinear systems by output feedback, in the case in which the measured output is corrupted by additive harmonic noise. We restrict our attention to systems which are passive with respect to the measured output, and the sensor disturbance has a finite discrete spectrum. A simple condition for zero-state detectability of passive partially linear systems is derived, and the result is employed to analyze the loop interconnection resulting from the application of internal model-based controllers to the perturbed plant. The analysis applies directly to the problem of stabilizing the angular velocity and/ or regulating the attitude of a rigid body using noisy angular rate measurements. The proposed controllers have a simple structure that exploit the passivity property of both the internal model and the plant. Simulation results show the effectiveness of the design.

Analysis and Evaluation of a Two Engine Configuration in a Series Hybrid Electric Vehicle

Abstract: The paper proposes the use of two engines as primary energy converter in a new generation refuse hauling vehicle with a series hybrid electric powertrain. The mission profile of such a vehicle in most U.S. cities is composed by an urban driving cycle for refuse collection, with low power requirements, followed by a highway section in which the vehicle travels at full power. Thus, while the engine must be sized for high power levels, it will be used at low loads for most of the time. The original Diesel engine is replaced with two smaller common-rail Diesel engines. The smaller engines are the same used in many mid-size European sedans and provide high peak efficiency. When the power required by the vehicle is low, the power request can be satisfied using only one of them, and the other one can be switched off. Thus, the only engine in use is running at high load (i.e., high efficiency) and the fuel consumption can be reduced in comparison with a single, bigger engine running at low load. An analysis of the typical vehicle driving cycle is carried out in order to evaluate the advantages of the dual engine architecture. The control strategy of the hybrid electric powertrain, which usually splits the power between the engine and the energy storage system, is extended with an additional degree of freedom, managing the power split between the two engines in order to minimize the instantaneous fuel consumption. A vehicle simulator is used to evaluate advantages and disadvantages of the proposed architecture, and to determine the best conditions for its implementation. Significant reductions of fuel consumption are obtained under proper conditions.Copyright © 2006 by ASME

Electrical drive-train design for the current electric land-speed-record car

Abstract: This paper explains the electrical drive-train development and performance of the Ohio State University's "Buckeye Bullet" (BB), and its success as the world's fastest electric land-speed car (August/October 2004). The electric car has been designed, constructed, operated and funded by a mix of Ohio State University's engineering students, and other external sponsors. A brief introduction is provided of the rules and distance constraints of the Land Speed Record (LSR) course. The overall design and performance parameters of the electric car are developed for achieving travel at over 300 mph in the straight-line course. The car description will be divided into three sections: energy storage, electrical power conversion, and electromechanical power conversion which explain our past and present usage of various battery technologies, of a PWM drive inverter, and of a custom designed induction motor. The tuning of the inverter-motor drive interaction, and the trained actions of the driver will be described, in achieving a smooth acceleration profile in a hostile salt-laden environment.