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Technical Paper

An Investigation of Property Changes of Copper-Free Brake Pads During Wear Testing: Pressure and Temperature Dependence of Pad Modulus, and the Correlation Between Modulus and Friction Coefficient

2021-10-11
2021-01-1276
Earlier publications have demonstrated that pad and disc properties change during storage and also during the SAE J2522 Brake Effectiveness Test Procedure. The current investigation was undertaken to find out how the properties change under milder braking conditions, using the SAE J2707 Wear Test Procedure. A copper-free formulation was selected for the investigation and tested on an inertia dynamometer using a front caliper designed for a passenger car. The pad dynamic modulus changed up or down throughout the test, depending on the test conditions. The pad dynamic modulus, the pad natural frequencies and the disc natural frequencies all decreased by the end of the test. Under high-speed, high-deceleration and high-temperature braking conditions, the pad surface region permanently expands, which results in reduced dynamic modulus and also leads to reduced pad thickness loss as compared with pad weight loss.
Technical Paper

Research on High-efficiency Test Method of Vehicle AEB based on High-precision Detection of Radar Turntable Encoder

2021-10-11
2021-01-1273
With the increasingly complex traffic environment, the vehicle AEB system needs to go through a large number of testing processes, in order to drive more safely on the road. For speeding up the development process of AEB and solve the problems of long cycle, high cost and low efficiency in AEB testing, in this paper, a millimeter wave radar turntable is built, and a high-precision detection algorithm of turntable encoder is designed, at the same time, a test method of vehicle AEB based on the detection data of radar turntable encoder is designed. The verification results show that methods described in this paper can be used to develop the vehicle AEB test algorithm efficiently.
Technical Paper

Potential and Challenges for Application-Specific Friction Characteristics of Race Brake Pads

2021-10-11
2021-01-1282
As a race driver hits the pedal to trigger the braking event, a dynamic load transfer takes place in the car. This is a similar kind of weight transfer experienced on the road while stopping any vehicle abruptly. Modern race cars such as FIA-regulated Grand Touring Car classes GT3 and LMGTE produce a significant aerodynamic downforce at a reasonably high efficiency level. In this type of high downforce race cars, load variations originated by aerodynamics are added onto the mass transfer. The combination of these effects provide a braking effect with this type of cars a highly transient character. At the same time, our customers are facing the challenge of strict technical regulations, usually forbidding brake control systems. In motorsport competition, car performance is of primary priority to help our customers win championships.
Technical Paper

Measurement of Particle Dynamics on the Real Vehicle in Different Driving Scenarios with Swarm Sensors

2021-10-11
2021-01-1299
Due to the increase in public attention in the analysis of non-exhaust emission sources because of the growing electrification of vehicles, measurements have been performed in recent years to develop a consistent test standard. In particular, the consideration of tyre and brake abrasion took a predominant position due to the small particle sizes. With measurements under controlled and laboratory-like athmosphere, for example for brakes on dynamometers, attempts have been made to create a uniform test standard according to the Worldwide harmonized Light vehicles Test Procedure (WLTP). However, a transfer to the real driving environment is not yet feasible because of many external disturbance variables, such as the wheel housing or atmospheric variables. Typical reference measurement sensors in the vehicle are only suitable to a limited extent for mobile operation due to their size and the necessary measurement infrastructure.
Technical Paper

Dynamic Brake Test Stand

2021-10-11
2021-01-1274
Nowadays, inertia dynamometers or roller dynamometers are used for the development and testing of vehicle brakes. However, these testing methods are either entirely unable to simulate dynamical conditions, close to real driving maneuvers, or they can do so approximately only at very high costs. This means that brakes, braking systems and brake-related assistance systems such as the ESC system can ultimately only be tested in a full prototype of the car, or before that on hardware-in-the-loop test stands. In the case of the ESC, these test stands have to simulate the behavior of the brake and the surrounding vehicle in real time, then stimulate the interfaces of the ESC sensors accordingly, and finally evaluate the reaction of the ESC system in different situations. The problem here, however, is that the braking system can only be approximated by simulations.
Technical Paper

Development of a Modeling Approach to Numerically Predict Filtration Efficiencies of Brake Dust Particle Filters

2021-10-11
2021-01-1285
According to the European Environment Agency, air pollution is the biggest environmental health risk in Europe. Since traffic is one of the main contributors of fine dust, technical solutions are necessary to reduce the particulate emission footprint of vehicles. Also the Health Effects Institute hosted recently an international workshop on non-tailpipe emissions. Brake dust filtration concepts have proven to be a promising solution to significantly reduce fine dust emissions from brakes directly at the source. While CFD simulations for inner-ventilated brakes have become state-of-the-art, a holistic models from particle generation and emission to particle dynamics in the vicinity of the brake is not yet available. However, a good modeling approach of particle tracks is essential to predict filtration efficiencies of brake dust particle filters.
Technical Paper

A New Approach to Describe Thermal Aging of Automotive Catalysts Containing Precious Metal Alloys

2021-10-04
2021-01-5095
Regarding thermal real-world aging of automotive catalysts, no deeply developed model or correlation is yet available. Therefore, a new method is developed. A diesel oxidation catalyst (DOC) is aged in the oven and indicated a systematic crystallite growth. Additionally, catalytic deactivation is only dependent on the crystallite size. The crystallite size acts as an indicator for the precious group metal (PGM) surface. This determines a quantitative correlation between the temperature stress, the crystallite size, and, finally, the catalytic activity for oven-aged samples of a DOC. On the basis of this result, the method for the description of oven aging is worked out. It is a physical model that gets as input parameters the aging temperature and aging time for oven aging. This information can be used to calculate the crystallite growth. Further, the corresponding catalytic activity for all species (NO, CO, HC) can also get calculated.
Technical Paper

Front Suspension Joint Integrity Analysis for Addressing Noise Issue Due to Torque Loss at Lower Control Arm Joint

2021-10-01
2021-28-0246
The lower control arm (LCA) is a part of the front suspension system which is mounted on chassis with flexible rubber bushing through-bolted joint which allows the control arm to swing up and down, absorb road bumps and reduce noise and vibrations as front wheels roll over bump or potholes. In bolted joints, torque is applied so as the joint develops a certain preload that is higher than the external loads and losses acting on the joint. But the loss of preload is evident over time which causes quality problems, reworks, or even joint failures. While moving over speed breakers/obstacles abnormal squeak noise is observed in the vehicle due to torque loss in the LCA joint. The intent of this study is to determine preload requirements in LCA joint and various factors contributing to preload loss by performing joint integrity analysis in CAE. Road load data acquisition (RLDA) with Wheel Force Transducer (WFT) is performed for different testing tracks.
Technical Paper

A Unique Methodology to Evaluate the Metallic Noise Concern of a Dual-Mass Flywheel in Real-World Usage Conditions

2021-10-01
2021-28-0249
Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration, and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMF’s are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the robustness of the DMF. In the present work, by capturing the Real-World Usage Profile (RWUP) conditions, a new methodology is developed to evaluate the robustness of a DMF fitted in a Sports utility vehicle (SUV). Ventilation holes are provided on clutch housing to improve convective heat transfer. Improvement in convective heat transfer will increase the life and will reduce clutch burning concerns. Cities like Mumbai, Chennai, Bangalore, roads will have clogged waters during rainy season. When the vehicle was driven in such roads, water enters inside the clutch housing through ventilation holes.
Technical Paper

Impact of Chemical Blowing Agent on Polypropylene Properties

2021-10-01
2021-28-0203
Weight reduction in automotive applications have led to the processing of thermoplastic polymers by foam injection molding. The density of the foamed polymer can be reduced up to 20%. Whilst, work has been reported on the weight reduction of the foamed polymer by using different types of blowing agent technologies, there has been limited studies in the areas of the sound transmission loss and sound attenuation properties of these materials. The present study is intended to understand the effect of chemical blowing agent (CBA) on the properties of polypropylene. The molded specimens were characterized using density, Differential scanning colorimetry (DSC), Thermogravimetric analysis (TGA), Fourier transform infra-red spectroscopy (FT-IR) and sound transmission loss (STL) measurements. Specimens were also tested for tensile properties, flexural properties, Izod impact strength and Heat deflection temperature (HDT) as per standard test protocol.
Technical Paper

Automatic Alert System to Enable Safe Ride and to Prevent Accidents in Two Wheelers and Three Wheelers

2021-10-01
2021-28-0233
In Midway accidents are general in nature in the highways. Vehicles meeting the accidents are not saved in a faster way for the rescue. This system generates the signal from the pressure sensor located under the seat during the operation of the vehicle. An Electronic Control Unit (ECU) has been deployed to provide the information about the passenger wearing helmet or not mobile phone contacts and the nearest safety officer with respect to the Global Positioning System installed in the vehicle. The signal from the hand bar sensor has been generated for the two-wheeler and the driver - cum pillion rider (TWDPR) such that the abnormality of the TWDPR rider and pillion rider is indicating the dearer contacts and the health the centres for the rapid recovery of the vehicle met with accident.
Technical Paper

Fault diagnosis of ball bearings using machine learning of vibration signals

2021-10-01
2021-28-0178
One of the major reasons for the failure of rotating machines are rolling element bearing defects. Failure of bearings leads to unplanned maintenance shutdowns and unsafe working conditions. For these reasons, it is very important to detect and identify the defects in rolling element bearings in its early stage. Vibration signals are well known for monitoring the conditions of rotating machineries. The performance of conventional intelligent fault diagnosis methods depends on feature extraction of vibration signals, which requires signal processing techniques, good proficiency, and human expertise. Recently, deep learning algorithms have been applied widely in machine health monitoring. Here in this study, a machine learning based model for the detection of bearing defects is analysed. The bearings used for this analysis is 6305 deep groove ball bearing. Defects like ball defect, outer race defect, and inner race defect were considered.
Technical Paper

Styling Parameter Optimization of the Type C Recreational Vehicle Air Drag

2021-09-30
2021-01-5094
Recreational vehicles have a lot of potential consumers in China, especially the type C recreational vehicle is popular among consumers due to its advantages, prompting an increase in the production and sales volumes. The type C vehicle usually has a higher air drag than the common commercial vehicles due to its unique appearance. It can be reduced by optimizing the structural parameters, thus the energy consumed by the vehicle can be decreased. The external flow field of a recreational vehicle is analyzed by establishing its computational fluid dynamic (CFD) model. The characteristic of the RV’s external flow field is identified based on the simulation result. The approximation models of the vehicle roof parameters and air drag and vehicle volume are established by the response surface method (RSM). The vehicle roof parameters are optimized by multi-objective particle swarm optimization (MO-PSO).
Technical Paper

Methodology to Derive RLD Based Durability Test Schedule for Gearbox Oil Seals

2021-09-22
2021-26-0461
Oil seal leakage is one of the major failure mode in gearbox / transaxle. Oil seal failures can be due to various reasons like high temperature, insufficient lubrication, failure due to external environment, incorrect fitment etc. Major reason for oil seal failure is insufficient oil flow inside gearbox when vehicle is running on gradient for long duration. When vehicle is running in hilly region, transmission will get incline leading to oil deficiency at one half of the transmission. Oil seal in this location will not get sufficient lubrication and will run dry. Also, there will be rise in local temperature at seal lip to shaft interface leading to failure of oil seal lip. Subsequently, oil leakage from transmission will start from this location when vehicle is running in different terrain. Due to continuous seepage, oil quantity in the transmission will get reduced and may lead to gear failure or seizure of bearing.
Technical Paper

Prediction of Tyre Dynamic Behaviour for NVH and its Experimental Validation in Anechoic Chamber

2021-09-22
2021-26-0303
In present scenario, tyre industry is more focused on providing maximum extent of NVH comfort to passengers by improvising the tyre design. Noise contribution from the tyres is classified in to three regions, viz., structure-borne (tyre vibrations), air-borne (tread pattern) and cavity noise (air cavity). In general, a Finite Element (FE) model of tyre provides an inherent advantage of analyzing tyre dynamic behavior. In this paper, an attempt was made to develop a three-dimensional FE tyre model and validate the same through experimental approach. The CAD Model of the tyre was generated through 3D image scanning process. Material property extraction of tyre was carried out by Universal Testing Machine (UTM) to generate Finite Element (FE) model. For validation of tyre FE model, Experimental Modal Analysis (EMA) and Noise Transfer Function (NTF) were conducted.
Technical Paper

Development of Compression Spring Variable Valve for Exhaust Mufflers

2021-09-22
2021-26-0289
The primary function of exhaust muffler is to reduce noise from the internal combustion engine without affecting its performance due to the impact of higher back pressure. The exhaust system back pressure is directly related to the engine fuel efficiency. The consumption of back pressure by the emission control system in BS IV regulation is about 30% from the total permissible engine limit, whereas in BS VI consumption is about 70%. The combination technologies used in BSVI and forthcoming RDE regulations such as TWC, GPF, DOC, DPF and SCR increases significant back pressure in exhaust system, hence the engine performance decreases. This demand robust method to control the exhaust back pressure for better fuel efficiency. Emission, noise and back pressure are the non-complimentary parameters in exhaust system development. The variable valve technology introduction in muffler is one method to optimize the above parameters.
Technical Paper

Methodology to Assess Headlamp Performance in Virtual Environment and its Correlation with Real World Driving Conditions

2021-09-22
2021-26-0130
Automotive exterior lighting systems has to meet several regulatory requirements & manufacture specific internal standards to achieve desired performance. These test specifications are usually generic in nature and formulated mainly to validate the standalone product under standard laboratory conditions. Most of the time these specifications are common for entire vehicle portfolio. The rationale of these standards is to define the basic illuminance in the safe braking distance. Thus, however, using the requirements in these standards to evaluate the performance of front lighting systems is only qualitative. Research on working out method for quantitative evaluation of front lighting system is necessary [1] In practice, however, the luminance levels at road surfaces are usually very dynamic; depend largely on the variations in vehicle parameters, ambient weather conditions, road surface uniformities and effects of light intensity & color contrasts on target visibility.
Technical Paper

Towards Establishing Continuous-X Pipeline Using Modular Software-in-the-Loop Test Environments

2021-09-22
2021-26-0412
Software-in-the-Loop (SiL) test environments are the ideal virtual platforms for enabling continuous-development, -integration, -testing -delivery or -deployment commonly referred as Continuous-X (CX) of the complex functionalities in the current automotive industry. This trend especially is contributed by several factors such as the industry wide standardization of the model exchange formats, interfaces as well as architecture definitions. The approach of frontloading software testing with SiL test environments is predominantly advocated as well as already adopted by various Automotive OEMs, thereby the demand for innovating applicable methods is increasing. However, prominent usage of the existing monolithic architecture for interaction of various elements in the SiL environment, without regarding the separation between functional and non-functional test scope, is reducing the usability and thus limiting significantly the cost saving potential of CX with SiL.
Technical Paper

Component S/N Curve Testing Methodology for Exhaust System Validation

2021-09-22
2021-26-0451
The exhaust system design and development need to be more flexible and easily adaptable for the requirement of dynamic changes to meet the upcoming emission and noise regulations. Durability of exhaust system components are evaluated through conventional bending moment testing using specified standard load conditions. Road load re-production test is an improvement of the conventional approach to predict component weld durability. It involves the systematic and sequential process of acquiring road load data such as sensor instrumentation, strain measurement at the test track, data processing and input to Bi-Ax testing. S/N Curve testing is introduced recently as an alternate method to minimize the use of road load reproduction testing. It involves prediction of rough force using transient response analysis followed by Bi-Ax testing for the derived high and low load forces to meet the target number of cycles to failure.
Technical Paper

Hybrid-Powertrain Development Approach to Reduce Number of Prototype Vehicles by Taking Right Decision in Early Development Phases on Engine Testbeds

2021-09-22
2021-26-0449
Today’s automotive industry is changing rapidly towards environmentally friendly vehicle propulsion systems. All over the globe, legislative CO2 consumption targets are under discussion and partly already in force. Hybrid powertrain configurations are capable to lower fuel consumption and limit pollutant emissions compared to pure IC-Engine driven powertrains. Depending on boundary conditions a numerous of different hybrid topologies- and its control strategies are thinkable. Typical approach is to find the optimum hybrid layout and strategy, by performing certain technical design tasks in office simulation directly followed by vehicle prototype tests on the chassis dyno and road. This leads to a high number of prototype vehicles, overload on chassis dynos, time consuming road test and finally to tremendous costs. Our developed approach is using the engine testbed with simulation capabilities as bridging element between office and vehicle development environment.
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