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Training / Education

Advanced Applications of Heavy Vehicle EDR Data

2021-05-24
This class will provide the student with the skills, knowledge, and abilities to interpret, analyze and apply Heavy Vehicle Event Data Recorder (HVEDR) data in real world applications. This course has been designed to build on the concepts presented in the SAE course Accessing and Interpreting Heavy Vehicle Event Data Recorders (ID# C1022).
Technical Paper

Design of Baja SAE Gearbox for Optimal Performance and Minimum Weight

2020-10-30
2020-32-2311
Baja SAE is an intercollegiate competition where teams design and build a single-seat off-road vehicle that is powered by a small 10 HP Briggs & Stratton engine. Due to this power constraint, it is crucial to optimize the vehicle's weight and performance. The purpose of this paper is to demonstrate the process of simulating, designing, manufacturing, and testing the gearbox of the vehicle. The design process began by creating a vehicle dynamics simulation, which included engine performance, CVT Shifting, tire slipping, vehicle mass, rotational inertia, air drag, rolling resistance, weight shift, and drivetrain efficiency. These calculations predicted acceleration times, top speed, and optimal gear ratio. An often-neglected parameter that was analyzed was the rotational inertia in the drivetrain system. The results showed the effective mass of the vehicle increased 12% above the weight of the vehicle, primarily due to the weight and size of the CVT primary pulley.
Technical Paper

Free Multibody Cosimulation Based Prototyping of Motorcycle Rider Assistance Systems

2020-10-30
2020-32-2306
Due to the increasing computational power, significant progress has been made over the past decades when it comes to CAD, multibody and simulation software. The application of this software allows to develop products from scratch, or to investigate the static and dynamic behavior of multibody models with remarkable precision. In order to keep the development costs low for highly sophisticated products, more precisely motorcycle rider assistance systems, it is necessary to focus extensively on the virtual prototyping using different software tools. In general, the interconnection of different tools is rather difficult, especially when considering the coupling of a detailed multibody model with a simulation software like MATLAB Simulink. The aim of this paper is to demonstrate the performance of a motorcycle rider assistance algorithm using a cosimulation approach between the free multibody software called FreeDyn and Simulink based on a sophisticated multibody motorcycle model.
Technical Paper

Measurement of the Forces from the Ground on the Tires for a Baja SAE Vehicle

2020-10-30
2020-32-2309
Knowledge of the forces on the vehicle is necessary for designing most of the vehicle subsystems, however little knowledge of the dynamic forces on small off-road vehicles is available. To measure the vertical and longitudinal forces on the tires of an off-road vehicle, a custom strain gauge system was designed and combined with Quarq tire pressure sensors while running in off-road conditions. The strain gauge system consisted of a carefully calibrated half-bridge Wheatstone bridge of 350 Ohm resistors in bending, feeding the change in voltages into the 20-bit ADC of a Cypress Semiconductor PSoC 5LP microcontroller for data interpretation and then recorded onto an SD card for later analysis. The Quarq Tyrewiz tire pressure sensors were placed on both the front and rear tires and the recorded pressures were converted to forces on the tire through calibration and helped remove the uncertainty of certain strain gauge values. Experimental data was found to agree with suspension models.
Technical Paper

Novel Modelling Techniques of the Evolution of the Brake Friction in Disc Brakes for Automotive Applications

2020-10-05
2020-01-1621
The aim of the presented research is to propose and benchmark two brake models, namely the novel dynamic ILVO model and a neural network based regression. These can estimate the evolution of the brake friction between pad and disc under different load conditions, which are typically experienced in vehicle applications. The research also aims improving the knowledge of the underlying mechanism related to the evolution of the BLFC (boundary layer friction coefficient), the reliability of virtual environment simulations to speed up the product development time and reducing the amount of vehicle test in later phases and finally improving brake control functions. With the support of extensive brake dynamometer testing, the proposed models are benchmarked against State-of-the-Art. Both approaches are parametrised to render the friction coefficient dynamics with respect to the same input parameters.
Technical Paper

Development of Friction Materials Regulations for Four Latin American Countries

2020-10-05
2020-01-1615
Brakes are the most important safety device in a vehicle, however there are few barriers to manufacture, import, or sell friction materials in most of the countries, including USA. European countries, with the ECE R90 program, are a big exception. International Transport Forum published in 2016 the “Benchmarking of road safety in Latin America” report, it mentions that worldwide 17.5 people in every 100,000 die in road accidents, however Andean countries mortality rate is 23.4 and South American 21.0, considerably higher than the worldwide average.
Technical Paper

Design of Water-Cooled Drum Brake System for Heavy-Duty Truck

2020-10-05
2020-01-1639
On account of the traditional friction brake for heavy-duty truck, the massive quantity of heat accumulating constantly because of frequent using of friction brake system in the long and steep downhill road leads to brake temperature rising rapidly. Affected by structure frictional couple installed in the closed environment of the brake drum, it is difficult to dissipate the heat in time via heat conduction, heat radiation and heat convection, and the heat fade phenomenon of the brake emerges easily. The heavy-duty truck would be in danger because of braking efficiency descending. This paper proposes an active water-cooled drum brake system to solve the problem. According to the principle of engineering thermodynamics, the structure and size of the back-stretching water jacket of brake shoe and the inner riveted the friction plate of brake drum are designed with restrained of GB 12672-2014 "Technical requirements and testing methods for commercial vehicle and trailer braking systems".
Technical Paper

Comparison of Particulate Matter and Number Emissions from a Floating and a Fixed Caliper Brake System of the Same Lining Formulation

2020-10-05
2020-01-1633
The particulate emissions of two brake systems where characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust number regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of WLTP tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle.
Technical Paper

Real-Time Dynamic Brake Assessment for Heavy Commercial Vehicle Safety

2020-10-05
2020-01-1646
This report summarizes initial results and findings of a model developed to determine the braking performance of commercial motor vehicles in motion regardless of brake type or gross weight. Real-world data collected by Oak Ridge National Laboratory for a U.S. Department of Energy study was used to validate the model. Expanding on previous proof-of-concept research showing the linear relationship of brake application pressure and deceleration additional parameters such as elevation were added to the model. Outputs from the model consist of coefficients calculated for every constant pressure braking event from a vehicle that can be used to calculate a deceleration and thus compute a stopping distance for a given scenario. Using brake application pressure profiles derived from the dataset, stopping distances for light and heavy loads of the same vehicle were compared for various speed and road grades.
Technical Paper

Investigation and Resolution of Vehicle Brake Judder

2020-10-05
2020-01-1609
One of the major discomforts while driving any medium to heavy commercial vehicle is brake judder. Brake juddering can be defined as vibrations felt on steering wheel or brake pedal or cabin floor, when brakes are applied at certain speeds and pressures. The frequencies of this judder lie as high as 500 Hz to as low as 10Hz. The brake juddering can be caused by a number of factors because of which providing universal solution only from brakes point of view is difficult. Some of the causes are related to part fitment, part quality, material selection, manufacturing process, Design consideration, environmental factors, peripheral aggregates etc. This paper gives us a brief idea about resolution of juddering problem in intermediate commercial vehicle by DOE method, and this methodology can be applied in heavy commercial vehicles also.
Technical Paper

Investigation and Mitigation of Brake Squeal Noise in Medium Commercial Vehicle

2020-10-05
2020-01-1607
The braking systems for modern day commercial vehicles with GVWs ranging above 7.5 metric tons use the typical s-cam drum brake system, where pressurised air is the actuating medium. The s-cam drum brake systems are popular today even after the advent and penetration of air disc brake systems, the main reasons being, cost-effectiveness, robustness, satisfactory performance and good component life. However, the brake systems of commercial vehicles (both M and N category) are frequently grappled with NVH issues particularly in the form of brake squeal noise (low frequency and high frequency). The noise with frequency more than 500 Hz can be generally defined as brake squeal. There has been a lot of work done and is being continued, at theoretical level, analytical level and experimental level to tackle with this issue.
Technical Paper

Methodology for Investigation and Resolution of Zero/Low/Unstable Lining Gap Concern in S-cam Brake System

2020-10-05
2020-01-1641
S-cam air brake system is provided in almost all commercial vehicles having tonnage above 7.5-ton. In S-Cam brake system, drum to liner gap (henceforth referred to as 'liner gap' or simply 'gap' for convenience) range is an important factor which can impact braking behavior during brake application. Different OEMs (Original Equipment Manufacturers) define different liner gap ranges between S-cam brake lining and brake drum. This range depends majorly on the internal mechanism deployed in ASA (Auto Slack Adjuster). When these liner gaps start lowering i.e. when they fall in the range of 0 to 0.4 mm, or they become unstable (checked by feeler gauge at inspection window provided on dust cover of S-cam) then it starts impacting brake behavior in the subject vehicles.
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