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Technical Paper

Sound Design in the Passenger Compartment with Active Noise Control in the Air Intake System

2001-04-30
2001-01-1432
In the future, the requirements of acoustic behavior in air intake systems will continue to increase. Active systems will be necessary to reach the higher legislative standards and customer expectations regarding noise levels. The optimization of the Active Noise Control System regarding the sound design in the interior is based on the transfer function between the engine and the passenger compartment as well as the design of the air intake system. This paper shows the development process, with a focus on the investigation of transfer functions in passenger cars and the computational calculation for the system configuration.
Technical Paper

Active Control of Automotive Air Induction Noise via Source Coupling

2001-04-30
2001-01-1613
Engine noise emanating from the air intake of automotive induction systems can be effectively suppressed through active noise control. Source coupling is used as the active noise control strategy. A small woofer, co-axially mounted inside the fresh air duct, is located in the plane of the fresh air intake and acts as the secondary noise source. An error microphone is located near the air intake and a synchronous reference signal is provided by an engine tachometer signal. This active noise control system has been tested on several engines. The radiated engine noise from the induction system has been effectively eliminated over the control bandwidth. The power draw of the speaker is minimal and the flow restriction of the actively controlled inlet has been significantly reduced compared to the production air induction system.
Technical Paper

An Electronically Tunable Resonator for Noise Control

2001-04-30
2001-01-1615
Many engineering systems create unwanted noise that can be reduced by the careful application of engineering noise controls. When this noise travels down tubes and pipes, a tuned resonator can be used to muffle noise escaping from the tube. The classical examples are automobile exhaust and ventilation system noise. In these cases where a narrow frequency band of noise exists, a traditional engineering control consists of adding a tuned Helmholtz resonator to reduce unwanted tonal noise by reflecting it back to the source (Temkin, 1981). As long as the frequency of the unwanted noise falls within the tuned resonator frequency range, the device is effective. However, if the frequency of the unwanted sound changes to a frequency that does not match the tuned resonator frequency, the device is no longer effective. Conventional resonators have fixed tuning and cannot effectively muffle tonal noise with time-varying frequency.
Technical Paper

Noise Control for Heavy Duty Trucks, a Systems Approach

2001-04-30
2001-01-1531
This paper describes a general noise control system design process. The methodology is applied to heavy duty trucks. The paper describes the benefits, for optimization purposes, of a systems approach versus a component approach. The role of both experimental and predictive approaches on the design process is outlined. Available noise control materials are briefly described, and lastly, an example of the results of the development of a noise control system by the experimental systems approach is provided.
Technical Paper

Comfort-Management

2001-05-14
2001-01-1738
Contradictory requirements like a quick heat up of the compartment vs. a quick heat up of the engine (especially in cars with fuel efficient engines) show that there is a need for a highly sophisticated climate control system to optimize the operation points. This could be done by a suitable system and a close interaction between the control systems for climate, engine and coolant management. Additionally we can improve the climate control system to a comfort management system by using sensors for air velocity and humidity. With today's technology we can build up a calculation model to determine a comfort-factor for the occupants and use this factor for the climate control instead of only using the compartment temperature as controlled variable.
Technical Paper

Performance of a NOX Adsorber and Catalyzed Particle Filter System on a Light-Duty Diesel Vehicle

2001-05-07
2001-01-1933
A prototype emissions control system consisting of a close-coupled lightoff catalyst, catalyzed diesel particle filter (CDPF), and a NOX adsorber was evaluated on a Mercedes A170 CDI. This laboratory experiment aimed to determine whether the benefits of these technologies could be utilized simultaneously to allow a light-duty diesel vehicle to achieve levels called out by U.S. Tier 2 emissions legislation. This research was carried out by driving the A170 through the U.S. Federal Test Procedure (FTP), US06, and highway fuel economy test (HFET) dynamometer driving schedules. The vehicle was fueled with a 3-ppm ultra-low sulfur fuel. Regeneration of the NOX adsorber/CDPF system was accomplished by using a laboratory in-pipe synthesis gas injection system to simulate the capabilities of advanced engine controls to produce suitable exhaust conditions. The results show that these technologies can be combined to provide high pollutant reduction efficiencies in excess of 90% for NOX and PM.
Technical Paper

On-Road Demonstration of NOx Emission Control for Heavy-Duty Diesel Trucks using SINOx™ Urea SCR technology - Long-term Experience and Measurement Results

2001-05-07
2001-01-1931
The Selective Catalytic Reduction (SCR) is one of the most efficient technologies to reduce nitrogen oxide (NOx) emissions arising from technical combustion processes [1,2]. For compliance with future emission limits for heavy-duty Diesel engines the SCR technology might play an important role [3]. In two long-term field demonstrations heavy duty (HD) trucks were equipped with SCR emission control systems (SINOx™-System) and were operated under daily working conditions. A number of measurements of both the performance and the activity of the catalyst during the entire operation time were performed. On the engine test bench the NOx reduction at the beginning of the road test was compared to the NOx-reduction at the end of the program. The initial NOx remained unchanged within the measurement accuracy of the analyzing equipment. On-road measurements of the emissions were done using an analyzer test cell installed on the loading area of the truck.
Technical Paper

ADM A NEW DRIVE-TRAIN MANAGEMENT

2000-06-12
2000-05-0389
The new drive-train system Automatic Drive-Train Management (ADM) controls all traction systems present in a vehicle. Applications include the all wheel drive feature in transfer cases and differential locks in axles. Compared to manually operated or automated traction control systems ADM has the advantage of transferring 100 percent of the torque automatically. The range of application for the ADM system would be a 4×2 truck tractor to a 6×6 off-road vehicle. A key feature of the ADM system is the synchronized engagement of gears in a two-speed transfer case while the vehicle is moving.
Technical Paper

Stop and go cruise control

2000-06-12
2000-05-0368
This paper will address the basic requirements for realizing a stop and go cruise control system. Issues discussed comprise: functional, sensor and basic HMI requirements, primary characterization of naturalistic stop and go driving, and the basic approach of the transformation of situational knowledge in an elementary controller.
Technical Paper

Adaptive, real-time traffic control management

2000-06-12
2000-05-0374
This paper presents an architecture for distributed control systems and its underlying methodological framework. Ideas and concepts of distributed systems, artificial intelligence, and soft computing are merged into a unique architecture to provide cooperation, flexibility, and adaptability required by knowledge processing in intelligent control systems. The distinguished features of the architecture include a local problem solving capability to handle the specific requirements of each part of the system, an evolutionary case-based mechanism to improve performance and optimize controls, the use of linguistic variables as means for information aggregation, and fuzzy set theory to provide local control. A distributed traffic control system application is discussed to provide the details of the architecture, and to emphasize its usefulness. The performance of the distributed control system is compared with conventional control approaches under a variety of traffic situations.
Technical Paper

Active Vibration Control of Driveline Systems

2000-06-12
2000-05-0318
Concern about axle noise/vibration/harshness (NVH) has been increasing with the growing popularity of sport utility vehicles, pick-up trucks, hybrid-vehicles and vans. Consumers want these vehicles to be quieter, with performance more like passenger cars. Traditional controls such as absorber-dampers and isolated/reduced vibration sources can solve some of the noise and vibration problems. An additional approach to enhancing NVH performance, is an active vibration control technique, which deals with the energy at the source. This paper describes an approach which combines an active vibration control technique with signature analysis, operational modal analysis and transfer path analysis to improve NVH performance. A flow chart of this is shown in Figure 1. Using this approach, we can identify and verify noise and/or vibration issues, find the root causes, and determine main contribution paths throughout driveline systems.
Technical Paper

The effect of engine misfire on catalytic converter and vehicle emissions

2000-06-12
2000-05-0325
A conventional automotive emission control system depends on the measurements provided by various sensors to control the air-fuel (A/F) ratio. Maintaining the A/F ratio close to stoichiometry permits catalytic converter to operate in an optimized efficiency, which reduces the exhaust emission. Malfunction resulted from engine misfire makes catalyst''s converting efficiency drop. Such a condition results in increased emissions as well as in damage to catalytic converters. So current researches are proceeded in response to the California OBD II (On-Board Diagnostics) and EOBD that will be adopted in Europe requirements for engine misfire detection in passenger vehicles. In this study, two methods to diagnose the misfire an approached: catalytic converter''s temperature measurement over the threshold exposure temperature to examine the catalyst''s damage, and the vehicle emission test over FTP-75 cycle by varying misfire rates.
Technical Paper

Exhaust emissions from medium- and high-mileage in-service cars with three- way catalytic emissions control system driven under Nordic driving conditions

2000-06-12
2000-05-0295
Exhasut emissions were determined from a fleet of some 50 cars that have been in normal private ownership service in Finnish driving conditions. These represent typical Nordic climate with strongly varying ambient temperatures between summer and winter months. All cars were petrol-fuelled, and had an up-to-date emissions control system based on a three-way catalytic converter. Tested vehicles represented model years 1990 to 1996. They had odometer ratings at the time of testing ranging from a low of 10,000 km up to a high of 373,000 km. The emissions performance was assessed using U.S. FTP75 urban during schedule. Testing was carried out at normal ambient temperatures (+22...23° ...). The paper reports an assessment of typical emissions performance as a function of distance driven encountered from normal TWC cars that have been in day-to-day use under sometimes quite rigorous driving conditions.
Technical Paper

Development of the All-Aluminum Light Body Structure for the Hybrid Electric Vehicle

2000-06-12
2000-05-0267
Global environmental problems have become the focus of much attention in recent years as an issue to be dealt with on an international scale. To alleviate these problems, automobile manufacturers are attempting to develop recyclable body parts and reduce vehicle exhaust emissions. These efforts have spurred the development of Low Emission Vehicles (LEV) and recyclable materials. One type of LEV is called the Hybrid Electric Vehicle which functions as either an electric car or an internal combustion vehicle and can operate as either type according to driving conditions. This hybrid vehicle is superior to conventional automobiles due to reduced exhaust emissions yet has the disadvantage of increased weight since it holds motors, batteries, and drivetrain control systems as well as a conventional internal combustion engine. We succeeded in eliminating this disadvantage by developing a lighter body using aluminum structural material.
Technical Paper

A development of electronic load sensing proportioning valve for control of brake pressure using direct adaptive fuzzy algoirthm

2000-06-12
2000-05-0266
In the brake system a proportioning valve which reduces the brake pressure at each wheel cylinder for anti-locking of rear wheels is closely related with the safety of vehicles. But, it is impossible for a present proportioning valve to exactly control brake pressure because mechanically it is an open-loop control system. So, in this paper, we describe an electronic brake pressure distribution system using a direct adaptive fuzzy controller in order to exactly control brake pressure using a closed-loop control system. The object of electronic brake pressure distribution system is to change a cut-in pressure and a valve slop of proportioning valve in order to have better performance of brake system more than that of the previous systems.
Technical Paper

Development of a new all-wheel-drive control system

2000-06-12
2000-05-0248
The new all-wheel-drive control system has been developed to improve stability, handling performance and safety under various road/operating conditions. This system consists of center differential and hydraulic transfer clutch which is electronically controlled according to road/operating condition. The center differential of this control system is in the form of composite planetary gear system without a starter ring. The output torque of transmission is distributed by this center differential 35% to front wheels and 65% to the rear wheels. It improves handling performance on dry road when the transfer clutch is open. On the other hand, when the slippery road condition is detected or motion of vehicle is disturbed, the actual torque distribution is modified by electronically controlled transfer clutch to improve stability and safety.
Technical Paper

Vehicle Driving Load Estimation for Longitudinal Motion Control

2000-06-12
2000-05-0249
An estimation algorithm for vehicle driving load has been proposed in this paper. Driving load is an important factor in a vehicle's longitudinal motion control. An approach using an observer is introduced to estimate driving load based on inexpensive RPM sensors currently being used in production vehicles. Also, the new torque estimation technique using neural network has been incorporated in this estimation algorithm to achieve better performance over variations in the automotive power transmissions process. The effectiveness of the observer-based method is demonstrated through the use of a nonlinear full vehicle simulation model in various scenarios. The proposed method using an observer has good performance, both over modeling error in powertrain system and under the uncertain environment of a running vehicle.
Technical Paper

Development of the Active Front Steering Control System

2000-06-12
2000-05-0242
For active front steering control systems that intervene in driver's operation to assist in the control of the vehicle's motion, the effect of the man-machine interface is much larger than for other conventional control systems. This paper focuses on human factors. The results of analysis regarding control effects and system design concerns are also described. The user benefits of this control system are improved vehicle stability and reduced driving workload. Both theoretical and experimental evaluations are described. Regarding the man-machine interface, the influence of the oversteer characteristic when braking and turning on driver's steering operation, the influence of driver reaction in system failure and steering wheel reaction torque when driving with the actuator are also analyzed.
Technical Paper

Development of traction control system

2000-06-12
2000-05-0246
Two major roles of the traction control system (TCS) are to guarantee the acceleration performance and directional stability. This paper proposes a new slip controller which uses the brake and the throttle actuator simultaneously. To avoid measurement problems and get a simple structure, the brake controller is designed using Lyapunov redesign method and the throttle controller is designed using multiple sliding mode control. Through the hybrid use of brake and throttle controllers, the vehicle is insensitive to the variation of the vehicle mass, brake gain and road condition and can achieve required acceleration performance. For the directional stability, a new method to measure the mixture of yaw rate and lateral acceleration with the speed difference of non-driven wheels is proposed. Using this measurement, the controller imposes individual pressure to the driven wheels and can maintain stability in the cornering or the lane change on the slippery road.
Technical Paper

Semi-lock brake system utilizing load sensing proportioning valve and spring membrane

2000-06-12
2000-05-0233
Anti-lock braking system is a modern braking system which could significantly improve directional stability and reduce stopping distance of a car. However this system still is too complicated and expensive to use on every car because its use complicated and control system. In this research, without using an expensive control system a combination of load-sensing proportioning valve and spring membrane was used as a main component to develop the effect of anti-lock braking system. Based on vertical load applied on each tire, a load-sensing proportioning valve could control fluid pressure to the appropriate level to lock the wheel. On the other hand, a spring membrane could fluctuate pressure of brake fluid in order to develop the effect of anti-lock braking system. The result shows that load-sensing proportioning valve alone could control fluid pressure in order to reach equal time lock between front and rear wheels.
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