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Technical Paper

Determining Hearing Threshold of Interior Noise Using Adaptive Procedure

2001-04-30
2001-01-1574
A jury evaluation study has been conducted to determine the hearing threshold of IP gauge stepping motor noise using a transformed up-down procedure. The stepping motor noise was recorded in an anechoic chamber and was used as a signal in the study. To determine the masked threshold, this signal was adjusted to various gain levels and mixed with interior engine noise at selected rpm as masking noise. In this study, the Adaptive Procedure was used, and a software application was developed for this purpose. Twenty subjects, selected based on hearing test results, participated in this jury evaluation. The findings of this study indicated that Adaptive Procedure is an effective approach in determining hearing threshold for automotive applications. A design criterion for acoustical characteristics of the IP gauge DC motor noise has been developed based on the results of this study.
Technical Paper

Dynamic EGR Estimation for Production Engine Control

2001-03-05
2001-01-0553
A dynamic EGR State Estimator (ESE) intended for production engine management systems (EMS) implementation is presented. It better describes the development of external exhaust gas recirculation (EGR) concentration at the engine intake ports during EGR transients than traditional models. The dynamics of EGR concentration time and spatial development in the intake manifold are described as a perfect mixing model in the intake manifold plenum volume and non-mixing plug flow in the intake manifold runners. The time scale of EGR transients precludes the use of traditional EGR measurement techniques for model verification. Instead a wide range air fuel (WRAF) sensor is used. Results are shown for a large variation in operating conditions and compared to the performance of a traditional model.
Technical Paper

A Model-based Environment for Production Engine Management System (EMS) Development

2001-03-05
2001-01-0554
This paper describes an environment for the development of production Engine Management Systems (EMS). This includes a formal framework and modeling methodology. The environment is based on using Simulink/Stateflow for developing a control system executable specification and a plant model. This allows for simulations of the system to be performed at the engineer's desk, which is identical performance with production software. We provide the details for incorporating production legacy code into the Simulink/Stateflow control system. The system includes a multi-rate, and event driven operating system. This system is developed to facilitate new algorithm development and automated software testing. Based on Simulink/Stateflow this specification will be suitable for use with commercial automatic code generation tools.
Technical Paper

A Model-Based Brake Pressure Estimation Strategy for Traction Control System

2001-03-05
2001-01-0595
This paper presents a brake pressure estimation algorithm for Delphi Traction Control Systems (TCS). A control oriented lumped parameter model of a brake control system is developed using Matlab/Simulink. The model is derived based on a typical brake system and is generic to other types of brake control hardware systems. For application purposes, the model is simplified to capture the dominant dynamic brake pressure response. Vehicle experimental data collected under various scenarios are used to validate the algorithm. Simulation results show that the algorithm gives accurate pressure estimation. In addition, the calibration procedure is greatly simplified
Technical Paper

Reliability of Resonant Micromachined Sensors and Actuators

2001-03-05
2001-01-0618
There are an increasing number of applications for resonant micromachines. Accelerometers, angular rate sensors, voltage controlled oscillators, pressure and chemical sensors have been demonstrated using this technology. Several of these devices are employed in vehicles. Vibrating devices have been made from silicon, quartz, GaAs, nickel and aluminum. Resonant microsystems are in constant motion and so present new challenges in the area of reliability for vehicular applications. The impact of temperature extremes, cyclic fatigue, stiction, thermal and mechanical shock on resonant device performance is covered.
Technical Paper

A Verification Study for Cam Phaser Position Control using Robust Engineering Techniques

2001-03-05
2001-01-0777
This paper describes the verification and comparison of position control algorithms for a continuously-variable cam phaser. Robust Engineering techniques are used. Two non-linear PID control algorithms are designed to control cam phaser position. The first algorithm is a more complex control strategy while the second is a thrifted approach that seeks to reduce throughput requirements. An L18 orthogonal array is established with noise factors that affect the quality of cam phaser control. Using the orthogonal array, the number of experiment test points required to characterize the control algorithm response is reduced from 8,748 to thirty-six. The test points of the orthogonal array are investigated experimentally on a motored engine outfitted with cam phaser hardware. The desired and actual cam position data are compared and analyzed for all points in the orthogonal array.
Technical Paper

Near and Far-Side Adult Front Passenger Kinematics in a Vehicle Rollover

2001-03-05
2001-01-0176
In this study, U.S. accident data was analyzed to determine interior contacts and injuries for front-seated occupants in rollovers. The injury distribution for belted and unbelted, non-ejected drivers and right front passengers (RFP) was assessed for single-event accidents where the leading side of the vehicle rollover was either on the driver or passenger door. Drivers in a roll-left and RFP in roll-right rollovers were defined as near-side occupants, while drivers in roll-right and RFP in roll-left rollovers were defined as far-side occupants. Serious injuries (AIS 3+) were most common to the head and thorax for both the near and far-side occupants. However, serious spinal injuries were more frequent for the far-side occupants, where the source was most often coded as roof, windshield and interior.
Technical Paper

US and UK Field Rollover Characteristics

2001-03-05
2001-01-0167
In this study, US and UK accident data were analyzed to identify parameters that may influence rollover propensity to analyze driver injury rate. The US data was obtained from the weighted National Automotive Sampling System (NASS-CDS), calendar years 1992 to 1996. The UK pre-roll data was obtained from the national STATS 19 database for 1996, while the injury information was collected from the Co-operative Crash Injury Study (CCIS) database. In the US and UK databases, rollovers accounted for about 10% of all crashes with known crash directions. In the US and UK databases, most rollovers occurred when the vehicle was either going straight ahead or turning. The propensity for a rollover was more than 3 times higher when going around a bend than a non-rollover. In the UK, 74% of rollovers occurred on clear days with no high winds and 14% on rainy days with no high winds. In the US, 83% of rollovers took place in non-adverse weather conditions and 10% with rain.
Technical Paper

Comfort and Usability of the Seat Belts

2001-03-05
2001-01-0051
Seat belts are the primary occupant-protection devices for vehicle crashes. Field statistics show that proper usage of seat belts substantially contributes to decreases in the fatality rate and injury level. To collect first-hand information regarding seat belt comfort and usability, a questionnaire survey was conducted. The most significant problems were found as belt trapping in the door, awkward negotiating with clothes, belt twisting, belt locking up, and difficulty to locate the buckle. The survey results indicated that drivers who are over 40 years old have more complaints than younger drivers. When the driver's age increases to 55 and above, belt pulling force and inappropriate and loose fitting of the belt on the body become major issues. Female drivers have more complaints than male drivers. Short statured drivers need both hands to pull and guide the retracting of the belt.
Technical Paper

LIN Bus and its Potential for Use in Distributed Multiplex Applications

2001-03-05
2001-01-0072
The increasing features and complexity of today's automotive architectures are becoming increasingly difficult to manage. Each new innovation typically requires additional mechanical actuators and associated electrical controllers. The sheer number of black boxes and wiring are being limited not by features or cost but by the inability to physically assemble them into a vehicle. A new architecture is required which will support the ability to add new features but also enable the Vehicle Assembly Plants to easily assemble and test each subsystem. One such architecture is a distributed multiplex arrangement that reduces the number of wires while enabling flexibility and expandability. Previous versions have had to deal with issues such as noise immunity at high switching currents. The LIN Bus with its low cost and rail-to-rail capability may be the key enabling technology to make the multiplexed architecture a reality.
Technical Paper

Consumers, Electronics, and the Link to Hybrid Vehicles and the Environment

2000-11-01
2000-01-C045
The interdependence of consumer features, new electronic and electrical architectures and hybrid propulsion systems are examined. There are two major forces driving future vehicle electronic and electrical systems, one is consumer demand for comfort and safety, and two is the demand for reduced fuel consumption and emissions. These forces are linked by the use of electronics to control vehicle energy generation and usage while providing managed solutions to these demands. Automobile consumer features are discussed and the case is made that these features will require more electric power to be installed on the vehicle. The presence of this increased electric power will then enable the hybrid vehicle functions that will benefit fuel economy and emissions performance.
Technical Paper

Suppression Technologies for Advanced Air Bags

2000-11-01
2000-01-C037
In May 2000 the National Highway Traffic Safety Administration (NHTSA) issued the final rule for the Advanced Air Bag regulations effective MY 2004 for vehicles to be sold in the United States. These regulations are in response to the air bag-induced injuries seen in the field, especially to children and short women. Advanced air bags require a vehicle manufacturer to design air bags for a broad array of occupants: 12-month-old, 3-year-old and 6-year-old children, and 5th percentile adult females, as well as 50th percentile adult males with new and more stringent injury criteria. Requirements for minimizing air bag risks include automatically turning off the air bag in the presence of young children or deploying the air bag in a manner much less likely to cause serious or fatal injury to out-of-position occupants. Technologies that disable the air bag in the presence of young children or adults in out-of-position are termed as "suppression technologies.'
Technical Paper

Challenges in Simulation and Sensor Development for Occupant Protection in Rollover Accidents

2000-11-01
2000-01-C038
Automotive occupant safety continues to evolve. At present this area has gathered a strong consumer interest which the vehicle manufacturers are tapping into with the introduction of many new safety technologies. Initially, individual passive devices and features such as seatbelts, knee- bolsters, structural crush zones, airbags etc., were developed for to help save lives and minimize injuries in accidents. Over the years, preventive measures such as improving visibility, headlights, windshield wipers, tire traction etc., were deployed to help reduce the probability of getting into an accident. With tremendous new research and improvements in electronics, we are at the stage of helping to actively avoid accidents in certain situations as well as providing increased protection to vehicle occupants and pedestrians.
Technical Paper

Smart Sensors for Future Robust Systems

2000-11-01
2000-01-C055
"Smart'' sensor concepts must be considered as the demands of advanced automotive systems increase. These concepts are strongly influenced by the architectural and dependability aspects of future systems. Key features of smart sensors are: communication (two way) with a digital data bus, self- calibration, error source compensation, self-diagnostics, and programmability for "plug and play.'' This paper contains a discussion of the basic future sensor requirements, and it assesses four major sensor technologies with respect to their suitability to meet these requirements. For each technology, the merits and demerits will be reviewed and an example sensing application will be given in order to demonstrate how the technology can be adapted to meet the future requirements.
Technical Paper

Solid Oxide Fuel Cell Auxiliary Power Unit - A Paradigm Shift in Electric Supply for Transportation

2000-11-01
2000-01-C070
Delphi Automotive Systems and BMW have been jointly developing Solid Oxide Fuel Cell (SOFC) technology for application in the transportation industry primarily as an on-board Auxiliary Power Unit (APU). In the first application of this joint program, the APU will be used to power an electric air conditioning system without the need for operating the vehicle engine. The SOFC-based APU technology has the potential to provide a paradigm shift in the supply of electric power for passenger cars. Furthermore, supplementing the conventional fuel with reformate in the internal combustion engine, extremely low emissions and high system efficiencies are possible. This is consistent with the increasing power demands in automobiles in the new era of more comfort and safety along with environmental friendliness.
Technical Paper

Dependable E/E System Drivers and Application Issues

2000-11-01
2000-01-C064
Today, electrical/electronic systems like ABS/power brakes and electric power steering are all designed to enhance, not replace a mechanical function. If an electrical or electronic fault occurs, the function reverts to the base mechanical capability. Future E/E systems, such as steer-by-wire and brake-by- wire replace mechanical linkages with electrical or optical signals as in computer networks. While these systems offer many potential safety benefits, they will require different strategies for dependability, and as with any vehicle system, they will further require that dependability be an integral part of the overall E/E system design. This paper illustrates how by-wire systems drive different dependability requirements and discusses some key technologies that are emerging to meet these requirements.
Technical Paper

Maximum Electrical Energy Availability With Reasonable Components

2000-11-01
2000-01-C071
The electric power required in automotive systems is quickly reaching a level that significantly impacts costs and fuel consumption. This drives the need to reconsider an electric energy management function. Fast evolving factors such as increasing power usage, and stricter engine management and reliability requirements necessitate a global vehicle approach to energy management. Innovations such as new powernet concepts (42 volt or dual voltage systems), new component technologies (high-performance energy storage, high efficiency and controllable generators), and global electronic and software architecture concepts will enable this new energy management concept. This paper describes key issues to maximize energy availability with reasonable components.
Technical Paper

Characterization of the Dynamic Response of a Cylinder Deactivation Valvetrain System

2001-03-05
2001-01-0669
This paper presents a theoretical and experimental study of a cylinder deactivation valvetrain system for the integration into an Engine Management System (EMS). A control-oriented lumped parameter model of the deactivation valvetrain system is developed and implemented using Matlab/Simulink, and validated by experimental data. Through simulation and experimental data analysis, the effect of operating conditions on the dynamic response is captured and characterized, over a wide range of operating conditions. The algorithm provides a basis for the calibration of the deactivation hardware. The generic characterization of the dynamic response can simplify the calibration parameters for the implementation in engine management systems.
Technical Paper

A Comprehensive Hazard Analysis Technique for Safety-Critical Automotive Systems

2001-03-05
2001-01-0674
Hazard analysis plays an important role in the development of safety-critical systems. Hazard analysis techniques have been used in the development of conventional automotive systems. However, as future automotive systems become more sophisticated in functionality, design, and applied technology, the need for a more comprehensive hazard analysis approach has arisen. In this paper, we describe a comprehensive hazard analysis approach for system safety programs. This comprehensive approach involves applying a number of hazard analysis techniques and then integrating their results. This comprehensive approach attempts to overcome the narrower scope of individual techniques while obtaining the benefits of all of them.
Technical Paper

Engine Control Using Torque Estimation

2001-03-05
2001-01-0995
In recent years, the increasing interest and requirements for improved engine diagnostics and control has led to the implementation of several different sensing and signal processing technologies. In order to optimize the performance and emission of an engine, detailed and specified knowledge of the combustion process inside the engine cylinder is required. In that sense, the torque generated by each combustion event in an IC engine is one of the most important variables related to the combustion process and engine performance. This paper introduces torque estimation techniques in the real-time basis for engine control applications using the measurement of crankshaft speed variation. The torque estimation scheme presented in this paper consists of two entirely different approaches, “Stochastic Analysis” and “Frequency Analysis”.
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