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Technical Paper

Accident Reconstruction with Data Recorded by Electronic Control Units in Vehicles with a Pre-crash Safety System

2018-04-03
2018-01-1440
Data recorded by vehicle-mounted electronic control units (ECUs) are highly useful in traffic accident reconstruction. In this context, event data recorders (EDRs) are airbag ECU components used to log information from crash events, typically providing data on speed, accelerator operation, RPMs and brake lamp activation for a period of around 5 s before a collision. Information on accelerator/brake lamp operation is very useful in understanding pre-crash driver actions, but the accuracy of EDR speed data must be checked in this regard. Such data are unlikely to reflect actual speed during brake-related skidding, for example, as they are determined from the rotational speed of the drive train. Thus, it is important to check the accuracy of EDR speed data in accident reconstruction. Meanwhile, pre-crash safety systems (PCSs) are also becoming more widespread in automobile usage today.
Technical Paper

Optimum Design Point to Recover Maximum Possible Exhaust Heat Over the Operating Range of a Small Diesel Truck Using Bottoming Rankine Cycle

2018-04-03
2018-01-1377
This paper focuses on waste heat recovery (WHR) system, which is an efficient technology to reduce fuel and vehicle carbon dioxide (CO2) emissions per kW of power produced. Wide variations of power of a vehicle make it difficult to design a WHR system which can operate optimally at all powers. The exhaust temperature from the engine is critical to design a WHR system. Higher the temperature higher will be the gain from the WHR system. However, as power drops the exhaust temperature drops which makes the WHR system perform poorly at lower powers. In this research, a small diesel truck engine was used to design a WHR system to produce additional power using a Rankine cycle (RC). The WHR system was designed at the rated power and speed of 42.8 kW and 2600 rpm, respectively. At this design point, around 15% additional power improvement was achieved resulting around 13% break specific fuel consumption reduction.
Technical Paper

An Integrated Test Facility for Suspension Dampers of Commercial Vehicle

2018-04-03
2018-01-1383
In the present scenario, delivering the right product at the right time is very crucial in automotive sector to grab the competitive advantage. In the development stage, validation process devours most of the product development time. This paper focuses on reducing the validation time for damper (shock absorber) variants which is a vital component in commercial vehicle suspension system. New test facility is designed for both performance test and endurance testing of six samples simultaneously. In addition, it provides force trend monitoring during the validation which increases the efficiency of test with an enhanced control system. This new facility is also designed to provide side loading capability for individual dampers in addition to the conventional axial loading. The key parameter during validation is control of damper seal temperature within the range of 70-90°C. A cooling circuit is designed to provide an efficient temperature control by re-circulating cold water.
Technical Paper

Vibration Isolation Analysis and Optimization of Commercial Vehicle Cab Suspension System

2018-04-03
2018-01-1405
This paper starts with study on the transfer characteristics, and the vibration isolation of the cab suspension. Vibration models of cab suspension and complete vehicle were built through multi-body dynamics software ADAMS. Finite element and multi-body dynamics were collaborated into the analysis of the transfer characteristics, the response and the isolation feature of cab suspension based on the complete vehicle. To improve the vibration performance of the cab suspension, improvements and optimization design were proposed with genetic algorithm method. The analysis results show that there only limited effectiveness on coil spring. So the improvement plans were proposed to replace the coil spring with an air spring and setting transverse damper. According to the plans, the original cab suspension was modified. The piecewise function method was used in fitting the characteristic of the air spring.
Technical Paper

A Study on Improvement of Sitting Posture Stability for Heavy Truck Drivers

2018-04-03
2018-01-1319
The driver’s seat in heavy trucks is designed for an upright driving posture with narrow back and cushion angles; thus, the seatback offers very little support. This makes the sitting posture prone to shifting during long trips, leading to loss of comfort and increase in fatigue. Sitting posture stability allows initial posture to be maintained during long drives, and the lack of stability causes fatigue and body pain during the drive. This study confirmed that enhancement of sitting posture stability of the driver’s seat in heavy trucks requires appropriate support from the cushion. The study also analyzed the support characteristics of each part of the cushion, and presented development guidelines of new cushion. Although subjective assessments of sitting posture stability have been performed, this study presented a method for quantitative and efficient assessment of sitting posture stability using the PAM-COMFORT simulation tool and virtual testing.
Technical Paper

Evaluation of Engine-Related Restrictions for the Global Efficiency by Using a Rankine Cycle-Based Waste Heat Recovery System on Heavy Duty Truck by Means of 1D-Simulation

2018-04-03
2018-01-1451
As a promising concept to improve fuel efficiency of a long-haul heavy duty truck with diesel engine, organic Rankine cycle (ORC) based waste heat recovery system (WHR) by utilizing the exhaust gas from internal combustion engine has continuously drawn attention from industry in recent years. The greatest achievable global efficiency may be, however, restricted by the engine. On one hand, engine operating conditions have direct impact on the temperature and the mass flow of exhaust gas, which is the waste heat source, on the other hand, the engine cooling system limits the heat rejection from the condenser of the WHR system. This paper aims to evaluate the impacts of the varied engine applications considering the effects of the WHR system on the global efficiency and engine emissions.
Technical Paper

Prediction of Wear Loss of Exhaust Valve Seat of Gasoline Engine Based on Rig Test Result

2018-04-03
2018-01-0984
The purpose of the present research was to predict, from the results of rig test, the amount of wear on exhaust valve seats in durability testing of gasoline engines. In the rig test, measurements were made of the wear loss ratios in a number of cases in which a number of factors in valve seat wear were within a certain range. The results for factors of high sensitivity were further used to create an equation for calculating the amount of wear. The amounts of wear calculated from the equation for calculating the amount of wear and from driving modes of actual engines were found from the results to show a high correlation with the amount of wear in bench tests and the amount of wear in vehicle tests. The influence of differing valve seat materials and valve diameters was also determined by rig test, indicating that the amount of wear in actual engines could be estimated.
Journal Article

Evaluation of Shot-to-Shot In-Nozzle Flow Variations in a Heavy-Duty Diesel Injector Using Real Nozzle Geometry

2018-04-03
2018-01-0303
Cyclic variability in internal combustion engines (ICEs) arises from multiple concurrent sources, many of which remain to be fully understood and controlled. This variability can, in turn, affect the behavior of the engine resulting in undesirable deviations from the expected operating conditions and performance. Shot-to-shot variation during the fuel injection process is strongly suspected of being a source of cyclic variability. This study focuses on the shot-to-shot variability of injector needle motion and its influence on the internal nozzle flow behavior using diesel fuel. High-speed x-ray imaging techniques have been used to extract high-resolution injector geometry images of the sac, orifices, and needle tip that allowed the true dynamics of the needle motion to emerge. These measurements showed high repeatability in the needle lift profile across multiple injection events, while the needle radial displacement was characterized by a much higher degree of randomness.
Journal Article

Fuel Consumption Reduction on Heavy-Duty and Light-Duty Commercial Vehicles by Means of Advanced Central Tire Inflation Systems

2018-04-03
2018-01-1334
Tire inflation pressure has a relevant impact on fuel consumption and tire wear, and therefore affects both CO2 emissions and the total cost of ownership (TCO). The latter is extremely important in the case of commercial vehicles, where the cost of fuel is responsible for about 30% of the TCO. A possible advanced central tire inflation system, which is able to inflate and deflate tires autonomously, as part of a smart energy management system and as an active safety device, has been studied. This system allows misuse due to underinflation to be avoided and adapts the tires to the current working conditions of the vehicle. For instance, the tire pressure can be adapted according to the carried load or during tire warm-up. An on board software is able to evaluate the working conditions of the vehicle and select the tire pressure that minimizes the energy expense, the TCO, or the braking distance, according to a multi-objective optimization strategy.
Technical Paper

Identification of Gear Shift Quality as a Key Attribute in Commercial Vehicle Development

2017-11-27
2017-01-7011
Indian automotive market has grown extremely competitive in the recent past. In order to meet the ever growing expectations of the customers, automobile manufacturers are compelled to offer their products under superior quality with supreme comfort. Customers wish of high levels of tactile comfort in the cabin compartment and effortless operation of peripherals will result in negligible fatigue and a pleasant drive, needs to be duly fulfilled. One has to focus more on Gear shift lever and Steering wheel, which are being the most sensitive tactile points in an automobile. The gear shift lever knob is frequently used and significantly influences the perception of the shift comfort for a driver during actual vehicle application.
Technical Paper

Association of Impact Velocity with Serious-Injury and Fatality Risks to Cyclists in Commercial Truck-Cyclist Accidents

2017-11-13
2017-22-0013
This study aimed to clarify the relationship between truck–cyclist collision impact velocity and the serious-injury and fatality risks to cyclists, and to investigate the effects of road type and driving scenario on the frequency of cyclist fatalities due to collisions with vehicles. We used micro and macro truck–cyclist collision data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤40 km/h and for medium-duty trucks at impact velocities ≤30 km/h. The fatality risk was 6% for heavy-duty trucks at impact velocities ≤10 km/h.
Technical Paper

On Road Truck Fuel Consumption Measurements in Real Conditions of Application and Speeds up to 90 km/h, Performed by a Towing Trailer with Electromagnetic Brake

2017-11-07
2017-36-0109
Environmental damage and climate change, air pollution, energy efficiency, fuel consumption and emissions are subjects for studies and legislations worldwide. Brazil must therefore be prepared to follow global trends in energy optimization tests and developments, including Euro 6 equivalent emission legislation. Considering the worldwide tendency for Real Driving Condition Test for heavy vehicles, the authors, using the developed Towing Trailer Prototype provided with an electromagnetic brake, performed fuel consumption on-road tests. For measuring fuel consumption on-road or on testing tracks, the developed system allows initially measurements with an independent auxiliary tank for short distances and measurement with an auxiliary tank connected with the truck tank for long distances. The tests were performed on road in real conditions initially by maximum speeds of 75 km/h.
Technical Paper

Method for Preventing Contamination on Trucks Cabin Side Using CFD

2017-11-07
2017-36-0080
Although ignored by most people not directly involved with highway and off-road commercial trucks operation the accumulation of dust and mud on cabin side can become a rather annoying issue. Besides adhering to the passengers clothes dirt contamination may also compromise driver visibility constituting a safety concern. For a truck manufacturer it can revert into quality complaints and negatively influence customers’ future buying decisions. In this context, fascia air deflectors are common devices used in truck industry to control the airflow over the cabin panels and ultimately prevent contamination deposition. This paper presents a methodology to avoid dust and mud accumulation on commercial trucks cabin doors based on the predicted airflow field by computational fluid dynamics (CFD) and a reference flow metric defined through a simple bench test.
Technical Paper

Supplier Base Optimization on MWM MAR-I Diesel Engines Launch

2017-11-07
2017-36-0139
Due to the introduction of PROCONVE MAR-I emission regulation, the Brazilian automotive industry developed Diesel engines to comply with this legislation demanding new components to automotive supplier base. However, at the same time this industrial sector was facing a difficult financial situation caused mainly by the crisis that impacted Brazil in last years. In 2015, around 27 local suppliers filed for bankruptcy affecting the whole Automotive Supply Chain. This scenario already represents a problem for current products established in market, but it represents a major challenge for new launches. This paper will discuss how MWM Motores Diesel made sourcing decisions and manage to develop components and suppliers in this harsh scenario, also looking for the supplier base optimization.
Technical Paper

Development of a Commercial Truck Parabolic Leaf Spring Using CAE Simulation with Correlated Experimental Stress Analysis Results

2017-11-07
2017-36-0126
The development costs that new design requires are subject to everyday discussions and saving opportunities are mandatory. Using CAE to predict design changes can avoid excessive costs with prototypes parts, considering the high reliability those current mathematical models can provide. This paper presents the methodology used during the development of a parabolic leaf spring for the rear suspension of a commercial truck, considering mainly the parabolic profiles and stress distribution on the leaves, calculated using CAE software (ANSYS) and experimental tests to measure the actual stress on each leaf, certifying the correlation between computational calculations and real stress on the parts during bench and vehicle evaluations.
Technical Paper

Vibration Absorber Application, Case Study: Mid-Size Truck Steering Wheel Vibration

2017-11-07
2017-36-0125
In this paper an alternative engineering solution to control vehicle steering wheel vibration is presented. The strategy is focused on the implementation of an effective tuned vibration absorber which also complies with time frame and costs requisites. The vibration levels in this case study are enhanced due resonances in the chassis frame and steering column. The tuned mass damper is basically a suspended mass attached on a vulcanized rubber body, aiming for the customer benefits; this solution can be classified as low cost as well low complexity for implementation. In this case study, a mid-size truck was used as a physical hardware and the data were collected through accelerometers on the steering wheel and other critical components. As a control factor, different tunings on different parts were applied to optimize the auxiliary system performance and robustness.
Technical Paper

Improve Frame Assembly Flexibility with Low Investment

2017-11-07
2017-36-0132
Commercial vehicles are being developed for long decades in Brazil creating a deep background on manufacturing process. With the current scenario a variety of different vehicles specifications (weight capacity, load distribution, torque, size, etc.) are being required by the market. Joints with bolts and nuts are the engineering solution for the most of the problems found in automotive engineering regarding commercial vehicles. Screw processes were made during the last 150 years. Nowadays current frame modifications on aftermarket are made with arc weld process that affects directly the material properties and the process needs to be performed by critical personal with training and capacity. In addition cost and timing does not fit for the best equation on how to proceed with the modifications. The solution proposed brings more flexibility on frame assemblies that can be extended to other products.
Technical Paper

Factors that Impact on Tire Structure Useful Life

2017-11-07
2017-36-0121
This work describes a statistic analysis of the service life of tires applied in off-highway trucks used in open-pit mining. Understanding the process of occurrence of structural failures, correlated to the fatigue mechanism and often observed in mechanic components, is of vital importance for the current industry. Since these failures usually happen suddenly, understanding them in the most diverse components submitted to cyclic loads helps analyzing the material’s progressive deterioration along time; it acts as a return to potential improvements in the product, giving feedback of computing simulation data; and it potentially increases operational safety by mitigating the consequences it has on the productive process and on the people exposed to such failures. The tires, components that integrate great part of the on wheels vehicles fleet - amongst them: transportation equipment, industrial mobile equipment and mining equipment - are inserted in this context.
Technical Paper

Vehicle Integration, Gear Material and Heat Treatment Effects on Rear Axle Whining Noise

2017-11-07
2017-36-0129
This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.
Technical Paper

Modelling a Rear Bumper of Goods Transport Vehicle Made of Glass Fiber Reinforced Polymer

2017-11-07
2017-36-0413
Due to the mass production process of the automobile industry, develop a product by reducing its cost has become an important aspect in its elaboration. This goal is to replace the higher cost material for an alternative that offers the same performance at a lower cost. The use of composite materials in the automotive industry has gradually evolved over the years. However, the use of composite materials in the structure of the automobile depends on a number of factors, such as large production scale, fast manufacturing process and economy, suiting the high demand of the automobile industry. Fiberglass composites are widely used in the market because of their good mechanical and physical properties combined with the comparatively low cost of production.
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