Showing papers by "Giorgio Rizzoni published in 1999"

Unified modeling of hybrid electric vehicle drivetrains

Abstract: Hybridizing automotive drivetrains, or using more than one type of energy converter, is considered an important step toward very low pollutant emission and high fuel economy. The automotive industry and governments in the United States, Europe, and Japan have formed strategic initiatives with the aim of cooperating in the development of new vehicle technologies. Efforts to meet fuel economy and exhaust emission targets have initiated major advances in hybrid drivetrain system components, including: high-efficiency high-specific power electric motors and controllers; load-leveling devices such as ultracapacitors and fly-wheels; hydrogen and direct-methanol fuel cells; direct injection diesel and Otto cycle engines; and advanced batteries. The design of hybrid electric vehicles is an excellent example of the need for mechatronic system analysis and design methods. If one is to fully realize the potential of using these technologies, a complete vehicle system approach for component selection and optimization over typical driving situations is required. The control problems that arise in connection with hybrid power trains are significant and pose additional challenges to power-train control engineers. The principal aim of the paper is to propose a framework for the analysis, design, and control of optimum hybrid vehicles within the context of energy and power flow analysis. The approaches and results presented in the paper are one step toward the development of a complete toolbox for the analysis and design of hybrid vehicles.

Modeling, performance analysis and control design of a hybrid sport-utility vehicle

Abstract: This paper proposes a unified power flow approach to the modeling of hybrid electric vehicles (HEV), resulting in a highly scalable and reconfigurable modeling tool. Furthermore, this simulation tool is used in conjunction with a fuzzy logic, ruled-based controller to optimize the energy efficiency through the control of the power flows of a parallel HEV configuration. Finally, this modeling and control approach is applied to the design and optimization of a hybrid electric sport-utility vehicle. The results show that this modeling approach provides the required modeling flexibility, and that the model and the control strategy based on this power flow approach can be optimized to yield significant fuel economy gains.

A model-based probabilistic approach for fault detection and identification with application to the diagnosis of automotive engines

Abstract: A model based parameter and state estimation technique is presented toward fault diagnosis in dynamic systems. The methodology is based on the representation of the system dynamics in terms of transition probabilities between user-specified sets of magnitude intervals of system parameters and state variables during user-specified time intervals. These intervals may reflect noise in the monitored data, random changes in the parameters, or modeling uncertainties in general. The transition probabilities are obtained from a given system model that yields the current values of the state variables in discrete time from their values at the previous time step and the values of the system parameters at the previous time step. Implementation of the methodology on a simplified model of the air, inertial, fuel, and exhaust dynamics of the powertrain of a vehicle shows that the methodology is capable of estimating the system parameters and tracking the unmonitored dynamic variables within the user-specified magnitude intervals.

Design of An IC Engine Torque Estimator Using Unknown Input Observer

Abstract: The torque produced by each combustion in an engine is one of the most important indices tied to internal combustion engine performance. In this paper, an approach is investigated to estimate engine torque. Instead of employing expensive and delicate combustion pressure sensors to directly measure indicated pressure in each cylinder, unknown input observers are exploited to estimate cylinder indicated torque using one or more low-cost measurements of crankshaft angular position. Necessary and sufficient conditions for the existence of such torque estimators for multi-cylinder engines are presented in the paper; these include the number of angular position sensors required and their suggested placement. Model reduction issues and the number of measurements required to obtain an acceptable estimate are also considered. The approach is applied to a six-cylinder industrial diesel engine.

Individual Cylinder Model of a General Aviation Aircraft Engine

Abstract: A need exists for the improvement of general aviation (GA) aircraft piston engine performance through the use of advanced control strategies and diagnostic studies. The life cycle time associated with the development of these technologies is always a concern when working with a cost-restrictive budget. Approaches to technological improvements through trial-and-error experimentation can work against a budget due to cost and development time. With the advancements in the computational speed of computers, simulations have become increasingly popular in helping engineers solve problems more quickly through a better understanding of the problem and better preparation of design strategies prior to the experimental implementation stage. The aim of the present work is to develop an intermittent combustion aircraft engine simulation that can provide insight to the complex system behavior, aid in the development of control strategies, and aid in the development of diagnostic studies. The GA aircraft individual cylinder simulation is the e rst of its kind and it has many potential applications. Some potential applications may include idle speed control, fuel control, spark control, and engine sensor and actuator diagnostics.

Race car trajectory determination by multi‐source acoustic emission analysis

Abstract: This talk presents a signal processing methodology to extract racecar trajectory and engine speed information from a multiple microphone array placed at track side. Phase differences, as well as Doppler shifts of the engine acoustic emissions from an array of microphones, provide multiple sources from which a robust determination of the vehicle trajectory can be extracted. Furthermore, time‐frequency analysis of the Doppler‐corrected signals provide a rich source of information about the instantaneous engine speed. The combination of both methods provides valuable information about the vehicle and engine characteristics. The analysis method used in this work is applied to acoustic emission data recorded by a track‐side array of four microphones. The data analyzed include synthetic validation and calibration data, as well as actual race data. Special attention was devoted to optimizing the microphone array configuration for maximum resolution given an array size. By carefully exploiting the inherent redundancies in the data, a robust and computationally efficient analysis method was successfully developed. The results demonstrate that valuable vehicle and engine parameters can be extracted from such an approach.