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Autonomous Vehicle Engineering: March 2018

2018-03-08
Editorial Autonomy's data binge is more like a 5-course meal. Big Data, Big Challenges Cloud services and multiple partnerships are issues the mobility industry grapples with as data implications expand outside the vehicle. Reinventing the Automobile's Design The convergence of electric propulsion, Level 5 autonomy, and the advent of car-free urban zones, is driving new approaches to vehicle design and engineering. When Steering Isn't Steering Anymore High-level autonomy requires new thinking for even basic vehicle controls. Steer-by-wire technology eases some of the complexities automated driving presents-and offers desirable new possibilities. Autonomy and Electrification: A Perfect Match? Combining SAE Level 4/5 functionality and EV platforms brings chal-lenges-and opportunities for cost reduction and systems optimization. Who's Ahead in the Automated-Driving Race? The 2018 Navigant Research Leaderboard study brings interesting insights on the industry's progress.
Technical Paper

Electric Vehicle Sound Quality

1999-05-17
1999-01-1694
Environmental concerns as well as regulatory requirements are driving the development of alternative vehicle propulsion systems. Electric vehicles (EV's) are attractive because they emit no pollutants. In this paper, we examine the sound quality characteristics of wind and powertrain noise in electric vehicles. Sound quality is an important attribute of EV's, because the expectation is that they will be very quiet due to the absence of an internal combustion engine. As we show in this paper, the absence of engine noise is both a blessing and a curse for sound quality. For wind noise, the results show that electric and gasoline vehicles have equivalent wind noise loudness levels at all speeds. However, at lower speeds (50-60 mph), the EV is judged to have more wind noise even though the level was the same as the gasoline vehicle! The difference is that, in the EV, there is no engine noise to mask the wind noise.
Technical Paper

The Effects of Retained Fluid and Humidity on the Evacuation of Critical Vehicle Systems

1999-05-10
1999-01-1630
In automotive assembly facilities worldwide, many critical vehicle systems such as brakes, power steering, radiator, and air conditioning require the appropriate fluid to function. In order to insure that these critical vehicle systems receive the correct amount of properly treated fluid, automotive manufacturers employ a method called Evacuation and Fill. Due to their closed-loop design, many critical vehicle systems must be first exposed to vacuum prior to being flooded with fluid. Only after the evacuation and fill process is complete will the critical vehicle system be able to perform as specified. It has long been thought, but never proven, that humidity and entrenched fluid were major hindrances to the Evacuation and Fill process. Consequently, Ford Motor Company Advanced Manufacturing Technology Development, Sandalwood Enterprises, Kettering University, and Dominion Tool & Die conducted a detailed project on this subject.
Technical Paper

Design of Front Wheel Active Steering for Improved Vehicle Handling and Stability

2000-05-15
2000-01-1619
Active steering has received lot of attention in the recent years because of the development of vehicle stability control systems and intelligent vehicle highway systems. Active steering systems allow for correction of the steer angle to achieve the desired vehicle yaw gain. The proposed system can be easily integrated with the vehicle stability control systems that use braking to control the vehicle yaw gain. The paper describes the concept of front wheel active steering system and the design techniques involved in order to achieve the desired performance from the system. The design techniques demonstrated in the paper do not address noise (gear rattles, motor noise, gear whine etc), electromagnetic compatibility and thermal issues related to DC motor and digital controller.
Technical Paper

Dynamics Simulation Research on Rigid-Elastic Coupling System of Car Suspension

2000-05-01
2000-01-1622
In modern car, to reduce car deadweight, lightweight technology is widely used; and to improve comfortable and handling performance, many rubber bushings installed between car body and suspension. These parts have difference characteristics during car running at high speed comparing these at static state. Accounting the suspension performance has a decisive influence on a car, the flexible parts should be taken into account in the suspension/steering system simulation model. As a deviant phenomenon, the steering wheel shimmy affects the suspension's dynamic characteristics greatly. To analysis this abnormal running state, the front wheel bounce tracks were figured out by using different front suspension model. The flexible parts installed in suspension are idealized respectively as rigid poles, flexible beams or forces, hence, the rigid suspension analytical model and the rigid-elastic suspension model analytical were built respectively.
Technical Paper

Steering Performance Evaluation - Heavy-Duty Highway Tractor Wander Test

1999-11-15
1999-01-3764
Heavy-duty highway tractors are the topic of various studies and tests to understand vehicle wander as a contributing factor to driver fatigue. Subtle variations in steering system characteristics can create measurable differences in performance, and operators may have different subjective opinions of the same system. This paper's purpose is to examine wander test setup and data analysis for tests conducted on an International® Model 9200 tractor-trailer at the Navistar Technology and Engineering Center in Fort Wayne, Indiana. Instrumented data and subjective ratings were collected using five power steering gears, evaluated by six drivers, operating over a specific test route.
Technical Paper

Molding Advancements for Phenolic Automotive Components

2000-03-06
2000-01-1164
This paper will explore molding systems that are improving phenolic composite molding specifically for the automotive component market. Topics will address processing advancements including innovative injection molding systems such as HTM™ (High Temperature Molding), RIC™ (Runnerless Injection Compression), utilization of “Live Sprues” in injection tools, and general automation of the processes which produce these components. Competition within the industry is becoming very intense and the utilization of these processes along with the advances in computer technologies will help to keep profits and reduce manufacturing costs. Molded Components that will be addressed in this paper are: Solenoid Cap - Standard compression molding vs. Automated compression molding, vs.
Technical Paper

Optimizing Variable Ratio Steering for Improved On-Centre Sensitivity and Cornering Control

2000-03-06
2000-01-0821
Research into the optimization of a Variable Ratio (VR) steering characteristic for rack and pinion steering gears was conducted. The VR steering characteristic was refined in a passenger car to achieve the optimum steering control for cornering and emergency maneuvers, whilst retaining the required on-centre performance needed for high-speed controllability. The research showed that the best steering performance resulted from high steering ratios on-centre, which rapidly reduce to lower ratios off-centre. This VR steering characteristic should result in vehicles with improved predictability of yaw and lateral acceleration response, whilst maintaining ease of on-centre control. This will reduce the skill level required in straight line running and maintaining control in emergency maneuvers.
Technical Paper

An Advanced Electrical Power Steering Motor

2000-03-06
2000-01-0824
Recently, EPS (Electrical Power Steering) is being widely applied in order to reduce fuel consumption and decrease installation problems of the power steering system. EPS also decreases development time and cost of the steering system due to its ease of tuning. Applying EPS technology to vehicles presents some challenges. The required output level of the motor is very high and causes high acoustic noise, excessive vibration, large torque ripple and large frictional losses. We have developed a very silent motor based on our unique technology. This involved a very unique electromagnetic force and mechanical vibration analysis method. Our super silent motor is so quiet, that the occupants of a vehicle can not distinguish the motor noise even when the motor is installed in the vehicle cabin.
Technical Paper

Variable Effort Steering for Vehicle Stability Enhancement Using an Electric Power Steering System

2000-03-06
2000-01-0817
This paper investigates a method for improving vehicle stability by incorporating feedback from a yaw rate sensor into an electric power steering system. Presently, vehicle stability enhancement techniques are an extension of antilock braking systems in aiding the driver during vehicle maneuvers. One of the contributors to loss of vehicle control is the reduction in tactile feedback from the steering handwheel when driving on wet or icy pavement. This paper presents research indicating that the use yaw rate feedback improves vehicle stability by increasing the amount of tactile feedback when driving under adverse road conditions.
Technical Paper

Development of Electric Power Steering (EPS) System with H∞ Control

2000-03-06
2000-01-0813
This paper deals with a case where H∞ control is applied to a basic control logic of a rack-assisted Electric Power Steering (EPS) system. In the body, the following three key features are described: Construction of the target controlled model including a vehicle Controller design for the model H∞ controller performance verification In this paper, it has been confirmed that H∞ control is valid as a basic control logic for the EPS system.
Technical Paper

A New EPS Control Strategy to Improve Steering Wheel Returnability

2000-03-06
2000-01-0815
This paper proposes a new Electric Power Steering (EPS) control strategy that enables improvement to steering-wheel returnability. Using a conventional EPS controller, frictional loss torque in the steering mechanism reduces steering-wheel returnability, which drivers occasionally perceive as unpleasant. This phenomena occurs in any EPS system regardless of motor type or mounting location. To improve steering-wheel returnability for EPS-equipped vehicles, we developed a new control strategy based on estimation of alignment torque generated by tires and road surfaces. This proposed control strategy requires no supplemental sensors like steering-wheel angle or motor-angle sensors. We experimented with this proposed control algorithm using a test vehicle and confirmed that it enables improved steering wheel returnability and also better on-center feeling.
Technical Paper

Correlation of Hydraulic Circuit Dynamic Simulation and Vehicle

2000-03-06
2000-01-0811
Higher demands from automotive customers for quieter vehicles and the reduction of noise and vibration levels from major sources like the engine necessitate better performance of other sources of noise and vibrations in a vehicle. One of these sources that Original Equipment Manufacturers (OEM) demand making quieter is the power steering system. The pressure ripple generated by the power steering pump transfers to the fluid lines where it can generate objectionable noise and vibrations. This can become an excitation force to the structure of a vehicle or the steering gear and can become a source of discomfort to the vehicle occupants. Attenuation of the pressure ripple within the hose assembly can result in significant reduction in noise inside the vehicle. The NVH research team at the Fluid System Products of Dana Corporation has developed “Dana's Virtual Test Rig (DVTR™),” - a hydraulic system simulation software.
Technical Paper

OSEKtime: A Dependable Real-Time Fault-Tolerant Operating System and Communication Layer as an Enabling Technology for By-Wire Applications

2000-03-06
2000-01-1051
The new generation of drive-by-wire systems currently under development has demanding requirements on the electronic architecture. Functions such as brake-by-wire or steer-by-wire require continued operation even in the presence of component failures. The electronic architecture must therefore provide fault-tolerance and real-time response. This in turn requires the operating system and the communication layer to be predictable, dependable and composable. It is well known that this properties are best supported by a time-triggered approach. A consortium consisting of German and French car manufacturers and suppliers, which aims at becoming a working group within the OSEK/VDX initiative, the OSEKtime consortium, is currently defining a specification for a time-triggered operating system and a fault-tolerant communication layer.1 The operating system and the communication layer are based on applicable interfaces of the OSEK/VDX standard.
Technical Paper

A Driver Direction Control Model and its Application in the Simulation of Driver-Vehicle-Road Closed-Loop System

2000-06-06
2000-01-2184
The research of driver behavior characteristics has been a focus of vehicle handling and stability performance. With the driver preview effort, many different driver preview models of direction control have been proposed and the simulations of driver-vehicle-road closed-loop system made. But in the simulation, most of the conventional models have the same precondition that the road was simply described as a pre-given preview course. How to simulate the driver dynamically deciding vehicle preview course based on the real road circumstance is the key to the further research of the driver model. In this paper, a new driver direction control model is established, which is called the Optimal Preview Lateral Acceleration (OPLA) Model and divided into three sub-models: driver’s information identification model, driver’s fuzzy decision model of vehicle preview course and driver’s performance first-order correction model.
Technical Paper

A Unique Approach for Data Analysis of Naturalistic Driver Behavior

2001-08-20
2001-01-2518
This paper describes an effort to gather lane-changing and passing driver behavior data using naturalistic observation methods. Participants were ordinary commuters who drove instrumented vehicles to and from work while data were automatically collected. The three types of data included driver, vehicle response, and vehicle interaction data via collected video, vehicle sensor, and radar systems. These data were combined using a data integration system to understand lane-change and passing maneuvers. Developed specifically for this project, this system allows analysts to understand and characterize lane-changing and passing maneuvers by presenting the three types of data in an intuitive, integrated manner. The integrated data will facilitate understanding of driver behavior. This understanding will assist designers in the development of future crash reduction countermeasures including Crash Avoidance Systems (CAS).
Technical Paper

A Distributed Architecture for Delivering Telematics Services

2001-08-20
2001-01-2516
With the wealth of information available on the Internet, there is a pressing need for a standards-based platform that allows the mobile vehicle to access telematics services that leverage this information in a safe and consistent manner while minimizing driver distraction. This paper discusses a distributed architecture that enables the rapid development and deployment of such services by offloading data- and compute-intensive operations to a remote server, while executing location-sensitive and vehicle-centric services on the vehicle. These services may range from safety and diagnostics services to multi-media infotainment. It further examines how the various underlying technologies from different spheres such as location, wireless, satellite, Internet and m-Commerce are brought together to complement each other, as well as the relevant emerging standards in each area.
Technical Paper

Development Experience with Steer-by-Wire

2001-08-20
2001-01-2479
Recent advances in dependable embedded system technology, as well as continuing demand for improved handling and passive and active safety improvements, have led vehicle manufacturers and suppliers to actively pursue development programs in computer-controlled, by-wire subsystems. These subsystems include steer-by-wire and brake-by-wire, and are composed of mechanically de-coupled sets of actuators and controllers connected through multiplexed, in-vehicle computer networks; there is no mechanical link to the driver. This paper addresses fundamental benefits and issues of steer-by-wire, especially those related to automated vehicle control and steering feel quality as perceived by the driver.
Technical Paper

Distance behavior on motorways with regard to active safety~A comparison between adaptive-cruise-control (ACC) and driver

2001-06-04
2001-06-0066
Present and future assisting systems are meant to support the driver in coping with the difficulties of driving. The design of the system properties and their limits helps to influence on the road-driving behavior directly and through teach-back effects. On the other hand, there is a potential risk of negative effects on the safety due to a division of tasks between the driver and the technical system. Bearing this in mind, the Automotive Engineering Department and the Department of Ergonomics of Darmstadt University of Technology were engaged by BMW AG to investigate the distance behavior of vehicles with and without ACC (Adaptive Cruise Control) which is used to control the speed and distance maintained to vehicles ahead and turning into the traffic. This trial was made with the aim of a representative and objective investigation of the behavior of the total system of driver-vehicle-environment in road traffic.
Technical Paper

The contributive benefits that state-of-the-art sound generation technology provides for advanced technology safety systems in the NADS program

2001-06-04
2001-06-0039
The use of synthetic test and research platforms is becoming more prevalent in the effort to capture a better understanding of critical vehicle and traffic safety issues as well as analyze and clarify high probability data. In the area of traffic safety, driving simulators have become the ultimate synthetic human factors research platform. These simulators expand the ability of researchers to explore issues that to date could only be safely studied from raw data interpretation or anecdotal observation and review. As a human factors research platform, realistic driving simulators must mimic and present accurate stimuli to the driver, which influence the dominant or effected human sensory organs. Driving a vehicle presents a ""cue hungr'' environment. The absence of critical or expected cues influences driver behavior.
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