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Viewing 1 to 30 of 18625
2015-09-29
Technical Paper
2015-01-2833
Ashley L. Dunn, Brian Boggess, Nicholas Eiselstein, Michael Dorohoff, Harold Ralston
Brake chamber construction allows for a finite stroke for pushrods during brake application. As such, the Federal Motor Carrier Safety Regulations (FMCSRs) mandate maximum allowable strokes for the various chamber types and sizing. Brake strokes are often measured during compliance inspections and post-accident investigations in order to assess vehicle braking performance and/or capability. A number of forensic studies have been performed, and their results published, regarding the effect of brake stroke on braking force and heavy truck stopping performance. All of the studies have relied on a brake supply pressure in the neighborhood of 100 pounds per square inch (psi). When brake strokes are measured in the field, following the Commercial Vehicle Safety Alliance (CVSA) procedure, the application pressure is prescribed to be maintained between 90 and 100 psi.
2015-09-29
Technical Paper
2015-01-2834
James Roger Lackore, Kevin Voss
Access method design for entry and egress of medium and heavy duty truck cabs and bodies is a critical aspect of vehicle design. Occupational injuries due to entering or exiting the truck cab, or climbing onto and off of the truck body, can be a significant percentage of a fleet’s lost-time incident rate. Many vocational trucks operate in both off-road and on-road conditions, and the slip resistance of the stepping surface is an importance design aspect. Examples of vocational vehicles that involve off-road operation include dump, refuse, utility, tree-trimming, and concrete trucks. Stepping surfaces in these applications must provide a balance between traction and the ability to shed water, snow, and mud. While there are a few methods and devices for measuring walking surface slip resistance, they are either complicated, or not well suited to measuring aggressive surfaces.
2015-09-29
Technical Paper
2015-01-2835
Sughosh J. Rao, M. Salaani, Devin Elsasser, Frank Barickman, Joshua L. Every, Dennis A. Guenther
This study was performed to showcase the possible applications of the Hardware in the Loop (HIL) simulation environment developed at The National Highway Traffic Safety Administration (NHTSA) Vehicle Research and Test Center (VRTC) research lab, to test heavy truck Electronic Stability Control (ESC) systems. In this study, the HIL simulation environment was used to recreate (an interpretation of) an actual accident scenario involving a single tractor-trailer. The scenario was then simulated with and without an ESC system to investigate the advantages afforded by the ESC system, if any. An acutal crash scenario reported in the Large Truck Crash Causation Survey (LTCCS), involving a single tractor-trailer was chosen. The crash scenario was interpretted as a path following problem and three possible driver intended paths were developed from the accident scene data. A path following algorithm was implemented in Simulink to simulate these paths.
2015-09-29
Technical Paper
2015-01-2845
Qi Chen
Recent years have witnessed an increase in the number of electrical loads being driven by semiconductor devices in the body control module or BCM rather than by relays in a typical truck with a 24V vehicle power net. This paper presents the major challenges caused by the higher voltage class of the truck supply and the longer cables, followed by an analysis of some key issues related to the design of truck BCMs to drive different loads. It offers some general guidance on practical design issues to BCM designers, such as an understanding of the advantages and disadvantages of different BCM architectural topologies, how to make a choice between a relay or a semiconductor driver, knowledge of the requirements of semiconductors used in truck applications etc.
2015-09-29
Technical Paper
2015-01-2846
Chunshan Li, Guoying Chen, Changfu Zong, Wenchao Liu
This paper presents a fault-tolerant control (FTC) algorithm for four-wheel independently driven and steered (4WID/4WIS) electric vehicles. The Unscented Kalman Filter (UKF) algorithm is utilized in the fault detection and diagnosis (FDD) module so as to estimate the in-wheel motor parameters, which could diagnose parameters variations caused by in-wheel motor fault. A sliding mode controller (SMC) is able to compute the generalized forces/moments to follow the desired vehicle motion. By considering the tire adhesive limits, a reconfigurable control allocator optimally distributes the generalized forces/moment among healthy actuators so as to minimize the tire workloads once the actuator fault is detected. An actuator controller calculates the driving torques of the in-wheel motors and steering angles of the wheels in order to finally achieve the distributed tire forces. If one or more in-wheel motors lose efficacy, the FDD module diagnoses the actuator failures first.
2015-09-29
Technical Paper
2015-01-2876
Shankar Patil, P Mahesh, Krishnan Sadagopan, Gokhul SA
In a tropical conditions , over a period of several months using 12 Nos. of New Generation 9-15T Intermediate Commercial Vehicles built with 4-Cyl 120HP BS3 Diesel engines run at regular interval from zero to 60000 Km. Field run data composed and analyzed with Intended Duty cycle for engine oil drain life estimation . The ICV trucks with sump capacity 0.083- 0.104 Liter/hp and SAE 15W40 viscosity of oil meeting API CH-4, API CI-4+ from group –I and Group-II base stocks are considered. The engine wear is more a function of silica concentration, load factor and age than the API category of oil. Oil drain interval is found proportional to the sump volume for the same stress on oil. Iron concentration and kinematic viscosity decide useful oil life with respect to the limits fixed by the engine manufacturer. In tropical conditions, field trials are carried out on 10T payload vehicles at higher temperature, humidity, dust levels and load factor than the other hemisphere conditions.
2015-09-29
Technical Paper
2015-01-2879
Evandro Silva
In recent years the commercial vehicle industry, specifically the heavy duty truck product line, has seen a rapid increase in the replacement of pure mechanical systems by electronic controlled systems. Engine, transmission, brakes, lighting, clusters, etc. are all monitored and/or controlled electronically. The adoption of electronic systems created a substantial change in the complexity of our products. Currently Diagnostic Trouble Codes (DTC) displayed on instrument clusters, in the majority of the cases, are no longer generated by a single sensor/component failure, instead these DTCs are triggered by a system monitor flag, result of a below average performance or a failure of an entire system. This new level of complexity makes it very difficult for the current diagnostic methods and tools, to identify what is causing the equipment to operate below ideal conditions.
2015-09-29
Technical Paper
2015-01-2895
Prasad Vegendla, Tanju Sofu, Rohit Saha, Mahesh Madurai Kumar, Long-Kung Hwang
This paper investigates the aerodynamic influence of multiple on-highway trucks in different platooning configurations. Complex pressure fields are generated on the highways due to interference of multiple vehicles. This pressure field causes an aerodynamic drag to be different than the aerodynamic drag of vehicle in no traffic condition. In order to study, the effect of platooning, three-dimensional modeling and numerical simulations are performed using STAR-CCM+® commercial Computational Fluid Dynamics (CFD) tool. The aerodynamic characteristics of vehicles are analyzed in five different platooning configurations with two and three vehicles in single and multiple lanes. A significant Yaw Averaged Aerodynamic Drag (YAD) reduction is observed in both leading and trailing vehicles. It is noted that YAD is based on the average result of three different yaw angles at 0, -6 and 6o. In single lane traffic, YAD reduction is up to 8% and 38% in leading and trailing vehicles, respectively.
2015-09-29
Technical Paper
2015-01-2896
Matthew Ellis, Joaquin Ivan Gargoloff, Raja Sengupta
The increasing importance of reducing greenhouse gas emissions and the ongoing evolution of vehicle-to-vehicle connectivity technologies have generated significant interest in platooning for commercial vehicles, where two or more vehicles travel in same traffic lane in relatively close proximity. This paper examines the effect of platooning on four increasingly aerodynamic tractor-trailer configurations, using a Lattice Boltzmann based CFD solver. Each platoon consisted of three identical tractor-trailer configurations traveling in the same lane at 65mph. Two different vehicle to vehicle gaps were studied, 5m and 9m, in addition to singleton vehicles, representing an effectively infinite gap. Aerodynamic drag for the lead, middle, and trailing vehicle in the platooning configurations were compared to the corresponding single vehicle tractor-trailer configuration.
2015-09-29
Technical Paper
2015-01-2897
Rick Mihelic, Jeff Smith, Matthew Ellis
Modern aerodynamic Class 8 freight tractors can improve vehicle freight efficiency and fuel economy versus older traditional style tractors when pulling Canadian style A- or B-Train double trailer long combination vehicles (LCV's) at highway speeds. This paper compares the aerodynamic performance of a current generation aerodynamic tractor with several freight hauling configurations through computational fluid dynamics evaluations using the Lattice-Boltzmann methodology. The configurations investigated include the tractor hauling a standard 53' trailer, a platooning configuration with a 30' separation distance, and an A-Train configuration including two 48' trailers connected with a dolly converter. The study demonstrates CFD's capability of evaluating extremely long vehicle combinations that might be difficult to accomplish in traditional wind tunnels due to size limitations.
2015-09-29
Technical Paper
2015-01-2901
Shaoyun Sun, Genghua Liao, Qiang Fu, Kelong Lu, Jing Zhao, Zhengzheng Li, Jiaquan Chen, Guang Shi, Sacha Jelic, Bo Li
Trucks are designed to carry heavy load, which implies high demanding design criteria for save operation. Heavy load means a lot of energy is needed to displace the load. During a stop, the kinetic energy is transferred into heat, which can be problematic in case of excessive proportions and/or when the heat cannot be removed from the system properly. The brake system therefore needs to be designed such to be able to absorb large of amount of heat and transfer the heat out of its system by either convection, conduction and/or radiation. All three heat transfer modes play an important role since the drum brakes of trucks are not much exposed to external airflow, a significant difference from disk brakes of passenger cars analyzed in previous studies. This makes it a complex heat transfer problem which is not easy to understand. Numerical methods provide insight by visualization of the different heat transfer modes.
2015-09-29
Technical Paper
2015-01-2902
Songzhi YANG, Dong Wang, Yan Dang, Liguang Li
Based on the real driving condition, this paper investigated the underhood flow field and temperature distribution of a heavy commercial vehicle by utilizing CFD commercial code FLUENT. To guarantee the authenticity of simulation , three kinds of driving conditions namely idling,peak torque, rated power were considered ,detailed computational model including front bumper, grill, cabin, all the underhood and underbody components, taking into account all heat transfer phenomenon including conduction, convection ,radiation in the engine compartment. By analyzing the velocity contour in different sections, underhood temperature field distribution and inlet temperature of condenser, intercooler and radiator, we found that serious air-recirculation existed in engine compartment under idling and peak torque conditions and the temperature of some components have exceeded its normal range in peak torque condition.
2015-09-29
Technical Paper
2015-01-2862
Hans Cuijpers, Mangesh Thorat
Introducing a new type of cold clamping as an application for mounting a bracket to a frame. This cold metal deformation process is recently introduced by KPIT & DAF Engineering (for DAF- Trucks, a Commercial Vehicle Manufacturer from the PACCAR GROUP} The current engineering of tubular mounting brackets has improved the product characteristics by eliminating critical welding process and introducing the new simple and robust cold clamping technology. This design model enables lower life-cycle cost consistent product with required performance, reliability & quality. Use of this bracket has lot of advantages over conventional welding process like simplified manufacturing process with an improved manufacturing tolerances. It eliminate the cost on sheet metal flattening and re-straightening metal tubes, improved Design for Assembly (DFA), easy to mount on vehicle without using any special tools and minimal assembly tolerances of the complete end assembly (less deviation).
2015-09-29
Technical Paper
2015-01-2863
Yogesh Sharma, Rahul Mehendiratta, Rishabh Raj Bhargava, Shubham Garg, Rohit Kumar Garg, Aditya Krishna, Ankit Goila, Aadityeshwar Saran Singh Deo
ABSTRACT
2015-09-29
Technical Paper
2015-01-2866
Saeil Jeon, Stacey Spencer, Paul Joiner
Lightweight solution is one of the keywords that we see every day. Developing smart, light and durable materials is one focal area that is inevitable to be done in the ground transportation sector. Another angle to look for is the protection and beautification of the substrate finish where surface treatment technology stands out. Combining both aspects is crucial in the industry for customer satisfaction. Recycled carbon fibers are used to form the reinforcement in the composite side, where they are infused or mixed with the matrix materials either in SMC (Sheet Mould Compound) or BMC (Bulk Mould Compound) format, depending upon the application. Glass fibers are usually used for the practical application, however considering further weight cut on the component, carbon fibers cannot be overlooked for their superior mechanical properties. However, due to the cost of carbon fibers many times the application may be over-designed.
2015-09-29
Technical Paper
2015-01-2868
John Woodrooffe, Daniel Blower
This paper examines truck driver injury and loss of life in truck crashes related to cab crashworthiness and investigate regulations and industry trends in relation to truck occupant protection. The paper provides analysis of truck driver casualties in crashes to provide a better understanding of injury mechanisms and to review regulatory and industry initiatives concerned with reducing the number of truck occupant fatalities and the severity of injuries. The commercial vehicle focus is on truck-tractors and single unit vehicles in the NHTSA Class 7 & 8 weight range. The study used UMTRI's Trucks Involved in Fatal Accidents (TIFA) survey file and NHTSA's General Estimates System (GES) file for categorical analysis and the Large Truck Crash Causation Study (LTCCS) for a supplemental clinical review of cab performance in frontal and rollover crash types.
2015-09-29
Technical Paper
2015-01-2885
Nicholas Schaut, Raja Sengupta
As part of the United States Department of Energy’s SuperTruck program, Volvo Trucks and its partners were tasked with demonstrating 50% improvement in overall freight efficiency for a tractor-trailer, relative to a best in class 2009 model year truck. This necessitated that significant gains be made in reducing aerodynamic drag of the tractor-trailer system, so trailer side skirts and a trailer boat tail were employed. A Lattice-Boltzmann based simulation method was used in conjunction with a Kriging Response Surface optimization process in order to efficiently describe a design space of seven independent parameters relating to boat tail and side skirt dimensions, and to find an optimal configuration. In two separate phases of optimization conducted with different constraints, the most influential parameters are identified in achieving significant aerodynamic drag reduction relative to a base configuration. The result was corroborated by on-road fuel economy testing.
2015-09-29
Technical Paper
2015-01-2753
Xiujian Yang, Ruocheng Zhu, Jin Gao
Tractor semi-trailer as a type of widely-used heavy duty freight vehicle is with relatively poor handling and lateral stability and is easy to fall into a lateral instability such as jackknife, trailer swing even causing an fatal accident. In this paper, attention is concentrated on a novel design concept for a tractor semi-trailer vehicle to improve the handling and lateral stability performances comprehensively by optimizing the whole vehicle arrangement and relevant design parameters. According to the previous public reports, the indexes such as Load Transfer Ratio(LTR), Static Rollover Threshold (SRT), Rearward Amplification Ratio (RWA) and Ratio of Yaw Rate (RYR) as very effective measures are often used to evaluate the handling and stability performances for a tractor-trailer vehicle. However, each of those indexes works individually and only focuses on a certain aspect with less relations to others.
2015-09-29
Technical Paper
2015-01-2759
Zhigang Wei, Limin Luo, Shengbin Lin, Litang Gao, Fulun Yang
The linear damage accumulation models based on Miner’s rule are widely used for fatigue damage assessment of vehicle components and systems. However, the uncertainty nature of the damage accumulation process is not considered in most of the applications, in others words, the methods themselves are deterministic in nature. In engineering design and validation, understanding the lower bound, upper bound of damage status in addition to mean behavior will be beneficial in risk and safety assessment, and these goals cannot be achieved without the probabilistic concepts and tools. This study presents a general damage assessment approach, which consists of two key parts: (1) an empirical probabilistic distribution obtained by fitting the fatigue failure data at various stress range levels; and (2) an inverse technique, which transforms the failure distribution to the damage distribution at any applied cycle.
2015-09-29
Technical Paper
2015-01-2736
Harikrishna TE, Murali P, Mufti MD
Vehicle handling is an important attribute that is directly related to vehicle safety. The rapid development of road infrastructure has resulted in a greater focus on safety and stability. Commercial vehicle stability and safety assumes higher significance because of high center of gravity (CG) and heavier loads. A gamut of parameters influence vehicle handling directly and indirectly. However, it is quite difficult to gauge through physical testing, the extent of each parameter’s influence on handling. Therefore, this paper examines vehicle handling by way of a sensitivity analysis through numerical simulation. A prototype vehicle is also instrumented and tested to confirm and validate the results of the suspension.
2015-09-29
Technical Paper
2015-01-2869
Sumit Sharma, Sandeep sharma, Umashanker Gupta, Ravi Joshi, shailesh pawar
Buses are one of the main and favorite sources of public transit in India. Thousands of people die or injure severely every year due to Bus accidents. Passenger injury in Bus accidents can be due to high stiff seat structures. Most of the occupants seated in the second row or further back were injured by hitting the seat back in the row in front of them. AIS023 (AUTOMOTIVE INDUSTRY STANDARDS) is one of the several mandatory standards from CMVR (CENTRAL MOTOR VEHICLES RULES) to ensure the safety during crash. As per AIS-023 passenger seat of bus should not cause injury because of high stiffness, on the other hand seat should also be able to carry the passenger force during accidents. With this mechanism AIS023 specifies minimum and maximum range deformations of seat back to minimize the passenger injury. This study includes the FE (Finite Element) analysis and design of Bus seat as per AIS023 test setup with LS-Dyna explicit tool.
2015-09-29
Technical Paper
2015-01-2873
Sumit Sharma, Sandeep sharma, Sanjay Tiwari, Umashanker Gupta
Years ago the main purpose of heavy duty truck is to carrying the loads, in the current scenario cabin comfort and safety is also equally important. With the improved infrastructure quality the average speed of these types of vehicle has also been increased. With the higher average speed, the chances of getting crash have also been increased. In order to provide safety to the driver, all the safety parameters should be considered in advance at the time of design and development of cabin. Sufficient survival space must be present at the time of crash. In order to provide optimum ride comfort, fully suspended cab was designed. The main aim of this study is to develop detailed 3D finite element (FE) model of fully suspended heavy duty truck cabin with detailed suspensions system and simulate crash test scenario presented in regulation ECE-R29 using LS-Dyna explicit solver.
2015-09-29
Technical Paper
2015-01-2843
Xu Kuang, Jianqiang Wang, Keqiang Li
Transport vehicles consume a large amount of fuel with low efficiency, which is significantly affected by driver behavior. An assessment system of eco-driving pattern for buses could identify the deficiencies of driver operation as well as assist transportation enterprises in driver management. This paper proposes an assessment method regarding drivers’ economic efficiency, considering driving conditions obtained from the GPS data and an online map database. To this end, assessment indexes are extracted from driving economy theories and ranked according to their effect on fuel consumption, derived from a database of 135 buses using multiple regression. The 12 selected characteristic indexes represent four aspects of driving behavior including speed, acceleration, engine and accessories control. A layered structure of assessment indexes is developed with application of AHP, and the weight of each index is estimated.
2015-09-29
Technical Paper
2015-01-2767
Sanjay L, Vijayakumar Chekuri, Arthanareeswaran Palaniappan
The emerging trends in commercial vehicle technology have increased the necessity for critical attribute engineering refinements. Drivability is emerging as one of the critical attributes in the automotive sector. The degree of smoothness in a vehicle’s response to the driver’s input is termed as drivability. This attribute has to be rigorously refined in order to achieve a brand specific vehicle character which will ensure a thorough product differentiation. In order to calibrate for a positive drivability feel, a methodology for evaluation of drivability is a prerequisite. The scope of this paper is aimed at detailing the methodology for evaluation of drivability attributes in commercial vehicles. Drivability is highly subjectively perceived attribute, therefore a subjective assessment technique to assess drivability attributes and sub-attributes are explained. Further, to quantify these attributes an objective measurement methodology is necessary.
2015-09-29
Technical Paper
2015-01-2733
Samraj Benedicts, Vivek Seshan
This paper is a study of reaction forces and its effects on the chassis due to rear idler position. Rubber Track layouts and traction have been focus of most research work, here we study the effect of Rear Idler position on layout and chassis structure through simulated analysis. An agriculture paddy combine harvester with rubber track is considered for the purpose of this work. Firstly the complete undercarriage is modeled in 3D using Creo and exported to Pro Mechanica for simulation. The real time forces, constraints were applied and the results were correlated to actual field results. The simulations were optimized through several iterations to match the field test results. The simulation and field test results show good agreement to the forces and constrains applied for simulation. Secondly the model was simplified for relative analysis and simulated for different rear idler positions with alternate tensioning methods.
2015-09-29
Technical Paper
2015-01-2731
Xingjian Gu, Guoying Chen, Changfu Zong
As a new form of electric vehicle, four-wheel-independent electric vehicle inherits a large number of advantages of in-wheel motor drive electric vehicle for the huge difference from the traditional vehicle in mechanical structure. The vehicle is driven by four in-wheel motors and the steering system is controlled by X-By-Wire (XBW). Steering system is liberated from traditional mechanical steering mechanism and forms an advanced vehicle with all-wheel independent driving, braking and steering. Compared with conventional vehicles, it has more controllable degrees of freedom. The integrated vehicle dynamics control systems help to achieve the steering, driving and braking coordinated control and improve the vehicle’s handling stability and safety. In order to solve the problem of lacking of vehicle state information in the integrated control, some methods are used to estimate the vehicle state of four-wheel-independent electric vehicles with XBW.
2015-09-29
Technical Paper
2015-01-2872
Massimiliano Ruggeri, Andrea Cervesato, Carlo Ferraresi
Performance requests and machine automation, in conjunction with new regulations for agriculture, earthmoving and construction machines, represent today the most difficult challenge for machine designers and researchers. Machine control systems complexity and functional safety regulation compliance, are the most complex requirements to deal with in new machines design. The paper describes a steering system design, of a 6 wheels agricultural front articulated self-propelled machine, that must comply with new regulations in terms of functional safety. The vehicle steering is driven by an electro-hydraulic system, totally controlled using by wire electronics; the rear wheels are independently steering and controlled. This architecture requires a too high functional safety performance level.
2015-09-29
Technical Paper
2015-01-2810
Piotr Lijewski, Jerzy Merkisz, Pawel Fuc, Maciej Siedlecki, Andrzej Ziolkowski
The paper describes the measurement of PM emission from an excavator engine under actual operating conditions. The exploration of the relations between the engine operating parameters and its emissions requires measurements under actual conditions of engine operation. The specificity of the emission measurements, PM in particular, requires technologically advanced measuring devices. The situation gets even more complicated when, beside the PM mass, we also need to obtain the PM size distribution and particle number (PN). An important technical issue is the difficulty in fitting the measurement equipment in/on the vehicle in operation (e.g. excavator), which is why the presented investigations were carried out in a laboratory under simulated operation. The laboratory technicians applied load to the engines through the excavator hydraulic system.
2015-09-29
Technical Paper
2015-01-2751
Igor Baseski, Kenneth Norman, David Ryan, Stefanie Stahara
At the request of the U.S. Army’s Tank Automotive Command (TACOM) laboratory facilities have been built to measure the suspension and mass parameters of the U.S. Army and civilian wheeled vehicles. This is part of an ongoing effort to model and predict vehicle dynamic behavior, so as to build vehicles that are less prone to roll over, have better handling stability, and perform better in rough terrain. These new machines, called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and Vehicle Inertial Properties Evaluation Rig (VIPER), are part of a set of large test devices at TACOM’s facility in Warren, MI. The SPIdER machine operates by holding the vehicle body fixed using a variety of clamps and chains that are arranged specifically for each vehicle. Hydraulic cylinders are used to move an “axle frame” in bounce or roll under each axle being tested. Combinations of bounce and roll can be used, which could be used to simulate roll under different loading conditions.
2015-09-29
Technical Paper
2015-01-2800
Meichun Peng, Xuqi Liu, Quanzhen Lin
This paper developed an engine emission test driving cycle of city transit buses with real road run mode. It was conducted real road emission test of city buses by a portable emission measurement system at 3 big cities in China, Guangzhou, Foshan and Shenzhen. Total of 107,784 sets of run mode and emission data was sampled, including of vehicle speed, engine speed and torque, exhaust emission of CO, HC, NOx, etc. 12 kinds of parameters were used to analyze the run mode basic characteristic , including of average engine speed and torque, max speed and positive torque, max negative torque, percentage of idle, etc. In addition, there was analysis of engine speed and torque distribution and exhaust emission of CO, NOX, and HC. Kinematic pieces theory was used to construct bus engine driving cycle. First, discrete the real road continuous run modes into mode pieces according to adjacent idle as node.
Viewing 1 to 30 of 18625