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2011-04-12
Journal Article
2011-01-0268
Jeffery R. Anderson, E. Harry Law
Traditional Electronic Stability Control (ESC) for automobiles is usually accomplished through the use of estimated vehicle dynamics from simplified models that rely on parameters such as cornering stiffness that can change with the vehicle state and time. This paper proposes a different method for electronic stability control of oversteer by predicting the degree of instability in a vehicle. The algorithm is solely based on measurable response characteristics including lateral acceleration, yaw rate, speed, and driver steering input. These signals are appropriately conditioned and evaluated with fuzzy logic to determine the degree of instability present. When the “degree of instability” passes a certain threshold, the appropriate control action is applied to the vehicle in the form of differential yaw braking. Using only the measured response of the vehicle alleviates the problem of degraded performance when vehicle parameters change.
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Technical Paper
2011-01-0453
Horst Salzwedel
The rapid increase of networked electronic control units in airplanes (Line Replaceable Units or Modules, LRUs/LRMs) and automobiles (ECUs) requires to move from CAN buses to higher performance buses. In aircraft the number of LRUs exceeded 100 in 1990 (B777) and is now ≻5000 (A380). Today, the number of ECUs in some automobiles also exceeds 100. Aircraft industry developed solutions based on standard switched Ethernet (AFDX) and standardized ECUs, called Integrated Modular Avionic units (IMA units) and common remote data concentrators (cRDCs) that are now flying in the Airbus A380 and A400M, the Boeing B787, and are being used in the design of future civil and military aircraft. During the last decade, automotive industry has been pursuing the development of specialized FlexRay bus solutions for automotive control and specialized MOST bus solutions for comfort electronics. However, some automotive companies are now also looking at Ethernet-based solutions.
2010-10-10
Technical Paper
2010-01-1680
Joseph Hartley, Andrew Day, Ioan Campean, Rod G McLellan, John Richmond
Tata Motors Limited plan to launch a range of full electric vehicles (FEVs) to the European market. Regenerative braking is advantageous in maximising range between recharging, but presents challenges of acceptable performance, weight, cost and the ‘blending’ of regenerative braking with friction braking. Control systems for regenerative braking have been developed by manufacturers to enable recuperation of kinetic energy which would otherwise be converted to heat and wasted through the use of friction brakes. This paper presents the approach taken by Tata Motors Ltd. to optimise the design and operation of a regenerative braking system to maximise range and energy efficiency. The Tata Ace EV is a Class N1 light commercial FEV with drive to the rear wheels only. This presents the challenge of harvesting energy from the axle which contributes a varying amount of the vehicle braking effort depending upon load.
2010-10-10
Technical Paper
2010-01-1682
Michael Herbert Putz
Scientists at the Austrian Institute of Technology (AIT), formerly Austrian Research Center, focused on investigating electro mechanical brakes (EMB) for automobiles. Research showed that EMBs can address brake distribution with regenerative and friction braking ("blending") at hybrid and electric cars due to the ability of the EMBs to be actuated as required (and do not automatically produce brake force at pedal activation). The target was to develop an EMB with low actuation force and energy that is simple and reliable, rolls back to disengage when power is off and acts as a parking brake. Several solutions were considered (with and without self-amplification). A pivotal mechanism with very high transmission ratio using eccentricity emerged as a favorable solution. Vienna Engineering (VE) took over and assumed the research during 2010. VE revealed that non-linear behavior facilitated low actuation forces at high braking torque and can use a controlled amount of self-amplification.
2010-10-10
Technical Paper
2010-01-1705
Matt Kero, Andrew Halonen
The objective of this paper is to highlight the design, analysis, testing, and application engineering performed to develop a lightweight brake drum made of aluminum metal matrix composite (MMC). Current cast iron brake drums are “design-limited” in the sense that new designs do not significantly change performance and they offer minimal weights savings. This paper will begin with the design of the drum with respect to SAE requirements, and then show how the drum was optimized using finite element analysis (FEA). FEA was used to predict maximum drum temperatures and stress levels reached during various braking events. There were a number of design iterations that led to the current design that has been extensively tested on the dynamometer and on a vehicle. In addition to test performance, the casting and infiltration challenges led to significant design changes.
2010-10-10
Technical Paper
2010-01-1703
Russell Creed, Andrew Creed, John P. Deconti
It is well known that heat generated during vehicle braking affects wear and stopping distances. To improve these conditions, supplemental retarders, such as exhaust brakes on diesel powered trucks and electromagnetic retarders have been used for years. Several of the diesel engines (below 7 Liters) are no longer designed to allow the use of exhaust brakes, and gas powered vehicles do not have that option either. Other options such as electromagnetic retarders are heavy, draw excessive amounts of current, and are a costly installation. To fill the void left by the elimination of exhaust brakes from some of these vehicles, and to provide an option that improves upon the undesirable aspects of electromagnetic retarders, a new technology; Liquid Cooled Disc Brakes, has been developed and designed into a product that fits on most popular truck chassis in the Class 2 - 4 range.
2010-10-10
Technical Paper
2010-01-1704
Florian Fuellgrabe, Hermann Winner, Ingo Hoffmann
Cast iron/aluminum composite brake disks are increasingly being employed, as they offer improved fuel efficiency and a lower unsprung mass. The achievable mass reduction and the product costs are determined by the joining concept. This paper presents two novel lightweight composite brake disks, which are produced using two different joining methods. The connection of the first lightweight brake disk under investigation in this study is implemented by friction welding. The second brake disk uses the forming processes spinning and flow forming. The requirements regarding the design of the concepts are presented in the course of this paper. Both lightweight concepts have been validated in standardized tests on a test bench. The results of the experimental investigation are discussed regarding to the key aspects of mass reduction, thermal and mechanical behavior and production.
2010-10-10
Technical Paper
2010-01-1708
Jae Seung Cheon
A dry Brake-By-Wire (BBW) system is one in which the existing hydraulic system is replaced by motor driven electro-mechanical calipers. Although it has yet to be introduced into series production, the attractive benefits of BBW have kept it in the mainstream of brake research for a number of years. In the current investigation, the BBW system is configured with electric wedge brakes in the front axle where high braking forces are required, while conventional electro-mechanical brakes are used in the rear axles. This paper will examine the feasibility of the current BBW system configuration through lab and vehicle performance tests including ABS (anti-lock braking system).
2010-10-10
Technical Paper
2010-01-1707
Yan-Sin Liao, Chien-Tai Huang, Chien-Tzu Chen, Shou-Yi Cheng, Bo-Ruei Chen, Fu-Yen Huang
A new design of integrated Electric Parking Brake system, called iEPB and integrated in the brake caliper, is introduced in this paper. It consists of an electrically operated brake unit and a hydraulically pressed unit independently, and uses a special self-locking mechanism instead of a screw device to increase the efficiency and the working speed. With all conventional EPB system's advantages, it also provides a stronger brake performance and a faster reaction time. In this paper, we describe the working principle of this new design at first, and then introduce the arrangement of the testing system, followed by a discussion of experimental data. The testing results prove the feasibility of this design. The conclusion paragraph summarizes the key points about the design of the iEPB system.
2010-10-10
Technical Paper
2010-01-1713
Vladimir Sergienko, Mikhail Tseluev, Sergey Bukharov
The work presents the results of numerical investigations of the effect of the load and velocity parameters of a mining truck moving over a long descending grade upon thermal conditions of the multidisc oil-cooled brake (MDOB) operation. The initial boundary-value problem for the heat transfer in the MDOB friction pair under frictional heating has been formulated and solved by the finite-element method. The computations performed for the friction pair of high-carbon steel against frictional composite material based on polymer binders. The effect of the load-velocity operation parameters on the thermal conditions of the mining truck MDOB was studied by way of a multifactor numerical experiment using a mathematical model of heat transfer in the MDOB friction pair.
2010-04-12
Technical Paper
2010-01-0629
Hamid Oral
A patent pending engine control system with torque sensor feedback is described. Upon detecting a loss in traction by means of a torque sensor, engine torque is adjusted via throttle paving the way for improved traction and enhanced stability. The throttle is reduced to a calculated value using engine characteristics, the torque sensor measurement and non-slipping wheel speed information. The advantages of the powertrain torque sensing as opposed to speed sensing are demonstrated thru a case study of a RWD SUV with an open rear differential. Simulations are used to prove the concept while the bandwidths of a number of physical systems contributing to the overall response time are ignored. Therefore the data provided in this paper should be treated relatively comparing speed sensors versus torque sensors. There are a number of engine torque reduction methods faster than throttle control such as spark retard and fuel shutoff.
2011-04-12
Technical Paper
2011-01-0212
Michael Roberts, Tejas Chhaya
The increasing usage of brake-by-wire systems in the automotive industry has provided manufacturers with the opportunity to improve both vehicle and manufacturing efficiency. The replacement of traditional mechanical and hydraulic control systems with electronic control devices presents different potential vehicle-level safety hazards than those presented by conventional braking systems. The proper design, development, and integration of a brake-by-wire control system requires that hazards are reasonably prevented or mitigated in order to maximize the safety of the vehicle operator, occupant(s), and passers-by.
2011-04-12
Journal Article
2011-01-0095
Gurkan Erdogan, Sanghyun Hong, Francesco Borrelli, Karl Hedrick
Intelligent tires are envisioned to be an important part of the future vehicle control systems and the three dimensional wireless MEMS accelerometers embedded inside the tire stand out as a promising candidate for the development of intelligent tires. The first part of the paper focuses on accelerometer based tire sensors for the estimation of slip angle and tire/road friction coefficient. We use a simple tire finite element model to generate lateral, tangential and radial tire accelerations for a fixed load and slip angle. The profiles are validated by using experimental data. The simulated acceleration profiles are used for the estimation of slip angle and tire/road friction coefficient. We present the estimation algorithms, promising simulative results and output sensitivities studies focused on the effects of changes in normal load, tire pressure and vehicle velocity.
2011-04-12
Technical Paper
2011-01-0120
Tim Lutz, Rajani Modiyani
The majority of commercial diesel engines rely on EGR to meet increasingly stringent emissions standards, creating a potential issue for military applications that use JP-8 as a fuel. EGR components would be susceptible to corrosion from sulfur in JP-8, which can reach levels of 3000 ppm. Starting with a Cummins 2007 ISL 8.9L production engine, modifications to remove EGR and operate on JP-8 fuel are investigated with a key goal of demonstrating 48% brake thermal efficiency (BTE) at an emissions level consistent with 1998 EPA standards. The effects of injector cup flow, improved turbo match, increased compression ratio with revised piston bowl geometry, increased cylinder pressure, and revised intake manifold for improved breathing, are all investigated. Testing focused on a single operating point, full load at 1600 RPM. This engine uses a variable geometry turbo and high pressure common rail fuel system, allowing control over air fuel ratio, rail pressure, and start of injection.
2011-04-12
Technical Paper
2011-01-0121
Nicholas R. Hirsch, Milad H. Mekari
Battlefield delivered fuel (jet and diesel) with required security, storage, transport, and dispensing equipment is estimated to cost $418/gallon [ 1 ], thus the need for very fuel efficient light weight engines for repower and future vehicles is critical. The U.S. Army RDECOM TARDEC Small Business Innovative Research (SBIR) Program funded Advanced Engines Development Corporation (AED) for the exploration, development and application of advanced diesel engine technologies and to incorporate these technologies into demonstrator engines, a 4-cylinder and V-8's. AED based these demonstrators on current production GM gasoline engine diesel conversions employing commercial-off-the-shelf (COTS) advanced diesel systems and engine components.
2011-04-12
Journal Article
2011-01-0581
R. Michael Van Auken, John W. Zellner, Jordan Y. Silberling, Joseph Kelly, Dean P. Chiang, Peter Broen, Amanda Kirsch, Yoichi Sugimoto
The Advanced Crash Avoidance Technologies (ACAT) program initiated by the National Highway Traffic Safety Administration had two major overall objectives. These were to develop a standardized Safety Impact Methodology (SIM) tool to evaluate the effectiveness of advanced technologies in avoiding and mitigating specific types of vehicle crashes; and to develop and demonstrate objective tests that are used in the SIM to verify the safety impact of a real system. Honda and Dynamic Research Inc. (DRI) had been developing and applying such SIMs for several years and had a Cooperative Agreement with NHTSA to further develop a SIM in order to determine the feasibility of developing estimates of effectiveness for specific not-yet-deployed safety technologies in the absence of data from real world or field operational tests, and linking it to the results from objective tests.
2013-04-08
Technical Paper
2013-01-1245
Myung Kug Moon, Murali Subramaniyam, Se Jin Park
The physiological stress and responses involved in last-minute braking situations are studied very little. The purpose of this study was to investigate older and younger drivers' physiological (central and autonomic nervous systems') responses and driving performance in two unexpected driving situations in a driving simulator. The subjects performed the test for two times, one for unexpected event while driving during 70 km/h and another driving during 90 km/h. An unexpected event described as while the lead-vehicle stops unexpectedly the subject vehicle needs to apply last minute braking. Nineteen healthy older (age: 65.6 ± 5.0 years) and nineteen healthy younger (age: 26.3 ± 2.0 years) drivers performed continuously simulated driving tasks with a simultaneous physiological parameters recording of each subject.
2013-04-08
Technical Paper
2013-01-1221
Ilyas Istif, Ovun Isin, Erdem Uzunsoy, Deniz Uzunsoy
Prediction of brake disc materials wear versus their formulation with brake operating conditions can play a critical role in the development of future brake disc materials. In this paper identification of the dry sliding wear behavior of magnesium (Mg) matrix (MMCs) reinforced with 0-3-6 wt % B4C particulates (B4Cp) was investigated. Wear tests were performed on a pin-on-disk configuration against SAE 1040 steel counter body under constant load and sliding speed. The wear resistance of composites was evaluated as a function of B4C particulates reinforcement. Identified models were based on experimental results. The wear load was considered as the input parameter, whereas the wear rate and friction of coefficient as the output parameter. A first order continuous-time linear model structure was chosen for the modeling. Simulations using the identified models were compared with experimental results and it was found that the modeling of wear process was satisfactory.
2013-04-08
Technical Paper
2013-01-1220
M.A.Z. Vasconcellos, R. Hinrichs
This work proposes to acquire images with multiple electron beam energies in the scanning electron microscope to get more information on the lateral distribution of the carbonaceous layer on the surface of friction films formed in brake couples, by combining the backscattered electron images with the behavior of the intensities of the major characteristic X-ray lines as a function of electron beam energy.
2013-04-08
Technical Paper
2013-01-1216
Ovun Isin, Ilyas Istif, Erdem Uzunsoy, Deniz Uzunsoy
The brake friction materials in an automotive brake system play important role in the overall braking performance of a vehicle. A previous study by the same authors was focused on wear testing for a 1040 steel disc interacting with Powder metallurgy (PM) copper-based brake lining material with and without MoS₂ additive at constant applied load and sliding velocity. In this paper, a non-Linear Autoregressive model (ARX) Model structure with sigmoid network having one hidden layer and nonlinear ANFIS (Adaptive Neuro-Fuzzy Inference System) model structure was used to find the best possible wear prediction results and both approaches have been applied to simulate wear behavior of the brake lining material. Preliminary results showed that ARX provides closer results to the experiments than the ANFIS model. As a result, nonlinear ARX modeling can be used as an effective tool in the prediction of brake lining material properties instead of time-consuming experimental processes.
2013-11-27
Technical Paper
2013-01-2762
Kannan Elumalai
Automotive industry is moving towards a stage that anticipates probability of accidents and instructs safety system to take immediate actions. Safety systems in automotive domain protect vehicle occupants and even pedestrians from accidents. High powered engines and good road infrastructure naturally thrills people to drive at very high speed which would result into forward collision. With the help of latest technologies, such accidents can be avoided and thereby many persons would be saved from major injuries. This does not indicate that people could drive as they wish irresponsibly. The safety systems will help vehicle occupants to be safe in case of inadvertent errors. Nowadays safety has become an important feature to be considered for selling vehicles.
2013-07-15
Journal Article
2013-01-9116
Ali Belhocine, Mostefa Bouchetara
The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disc is actually used to identify the factor of geometric design of the disc to install the ventilation system in vehicles. The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.
2013-11-11
Technical Paper
2013-22-0001
Jonas Östh, Jóna Marín Ólafsdóttir, Johan Davidsson, Karin Brolin
The objectives of this study are to generate validation data for human models intended for simulation of occupant kinematics in a pre-crash phase, and to evaluate the effect of an integrated safety system on driver kinematics and muscle responses. Eleven male and nine female volunteers, driving a passenger car on ordinary roads, performed maximum voluntary braking; they were also subjected to autonomous braking events with both standard and reversible pre-tensioned restraints. Kinematic data was acquired through film analysis, and surface electromyography (EMG) was recorded bilaterally for muscles in the neck, the upper extremities, and lumbar region. Maximum voluntary contractions (MVCs) were carried out in a driving posture for normalization of the EMG. Seat belt positions, interaction forces, and seat indentions were measured. During normal driving, all muscle activity was below 5% of MVC for females and 9% for males.
2013-09-24
Technical Paper
2013-01-2396
Mohamed H. Zaher, Sabri Cetinkunt
This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. A rule based control algorithm is developed and is tuned for different work cycles and might be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work-machine and its position via GPS, and maps both of them to the gains.
2013-09-24
Technical Paper
2013-01-2392
Daniel Blower, John Woodrooffe
Heavy truck rollover remains a primary factor in truck driver fatalities and injury. Roll stability control (RSC) and electronic stability control (ESC) are technologies that have been introduced to reduce the incidence of rollover in heavy truck crashes. This report provides an analysis of the real-world experience of a large for-hire company that introduced RSC into its fleet starting in 2004. The carrier provided a well-documented set of data on the operations of its truck-tractors, including both those equipped with RSC and those that did not have RSC installed. The purpose of the analysis is to determine the effect of RSC on the probability of rollover, as well as to identify other factors that either contribute to rollover or help reduce its incidence. This study presents results on the incidence of rollover both in terms of rollovers per 100 million miles traveled and the percentage of crashes that resulted in rollover.
2013-09-24
Technical Paper
2013-01-2352
Paul C. Niglas
The new RSDII (Reduced Stopping Distance, phase 2) regulation creates an increased emphasis by the heavy truck industry to ensure that brake systems are properly chosen and optimized. This regulation has led to vehicles being fitted with much more powerful brakes. However, despite the intent of these new brakes to provide larger braking forces for shorter stopping distances, the performance of vehicles is still limited by the maximum friction coefficient between the vehicle's tires and the road. In order to get the most out of these new brakes, it is essential that the entirety of the vehicle be taken into account. With the use of a hardware-in-the-loop simulation tool, this paper will present stopping data predictions from a variety of vehicles of varying brake torque and wheelbase. It will be shown how these factors change the way a vehicle behaves under panicked stopping situations.
2013-09-24
Technical Paper
2013-01-2350
Matt Kero
The commercial vehicle industry has seen regulations create new requirements over the last few years. Reductions to stopping distance, improvements to vehicle emissions, and the overall need for lighter weight vehicles has caused the commercial vehicle industry to look for new solutions to meet these needs. One such solution is light-weight aluminum metal matrix composite (MMC) brake drums. Aluminum MMC brake drums create the opportunity to reduce weight, lower brake temperatures, improve brake life cycle, and improve brake performance. During the evaluation of these aluminum MMC components it has been seen that existing procedures do not create accurate comparisons for this new material. Current procedures were designed and implemented for cast iron braking solutions. This paper will outline two procedures; FMVSS121 dynamometer burnishing and SAE J2115 wear performance testing, that do not allow direct comparisons from brake system to brake system to be made.
2013-09-30
Technical Paper
2013-01-2071
Carlos Agudelo, Raleigh Belcher, Dhawal Dharaiya
This paper presents three main topics which proved useful during the systematic resolution and testing program to confirm the ability of the proposed friction material to conform to the performance requirements indicated on the TP-121D [1] dynamometer test. Initially, the paper presents some commonalities and differences between the vehicle FMVSS 121[2], the dynamometer TP-121D and the SAE J2115-06 [3] test protocols. The second part of the paper elaborates on the implementation of the methodology established on the ASTM E1169-07 [4]. This standard relies on Design of Experiments (DOE) methods to assess the robustness of a given test method when testing on the extreme values allowed for key test conditions. The DOE used a three-factor, two-level, fractional factorial design to investigate the influence of (a) cooling air speed, (b) brake power as the combination of test inertia and deceleration settings, and (c) brake adjustment method.
2013-04-08
Technical Paper
2013-01-0493
Ruth Hinrichs, Marcos A.Z. Vasconcellos
Asbestos has been banned in many countries as industrial material, however the utilization of those fibers in brake linings results in friction properties that are so convenient, that linings containing them are still commercially available. To replace asbestos a large number of mineral phases is utilized in the formulation of polymer based friction material, and it is sometimes difficult to establish if they are present or not in finished brake pads and linings. Several clay minerals have been mistaken for asbestos because they present X-ray diffraction peaks that overlap with the diagnostic asbestos peak. A method to distinguish between the presence of regulated fiber minerals and allowed clay minerals in brake linings is presented using X-ray diffraction in association with a thermal treatment.
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