ARAI Journal of Mobility Technology

Design Optimisation of Engine Mounts for Improved Vibration Isolation in Three Wheeled Passenger Vehicles

2024-05-16T12:10:10+00:00

Powertrain mounting systems play a crucial role in the overall functioning of three-wheeled passenger vehicles equipped with a single-cylinder diesel engine. Primarily, engine mounting systems are tasked with isolating the vehicle and its occupants from the vibrations produced by the engine. A properly designed engine vibration isolation system should ensure the stable positioning of the powertrain within the vehicle, even when subjected to dynamic forces and torque loads. Furthermore, it should accommodate the general motion of the powertrain and prevent any contact between the engine, transmission, and associated components of the vehicle.

The mounting system should additionally shield the engine from loads imposed by chassis torsion or twists while minimizing the shock loads transmitted to the engine caused by road undulations. Moreover, the mounting system needs to prevent the powertrain system frequency from coinciding with suspension wheel hop and tramp frequency, as well as structure-borne and human-organ resonances.

Therefore, a comprehensive examination of the powertrain mount design is crucial to ensure improved vibration isolation.

This paper delves into the design considerations of a powertrain mounting system for a three-wheeled passenger vehicle featuring a transversely mounted single-cylinder diesel engine at the rear. The powertrain relies on three elastomeric mounts, with two positioned at the front of the engine and one at the rear.

In this paper, a design rationale and calculation methodology for determining the stiffness and location of a powertrain mounting system are presented. This approach allows for changes in mount positions within allowable practical limits, considering packaging constraints. The analysis involves studying the vibration patterns of the existing powertrain configuration by examining its rigid body mode shapes. The paper proposes an approach to modifying the stiffness and positions of the elastomeric mounts with the goal of achieving >80% modal purity. This methodology focuses on mitigating vehicle vibrations and noise associated with these mounts, with the primary aim of enhancing the performance of the mounting system, ultimately leading to improved vibration isolation performance of the powertrain mounts.

Keywords: Engine Mounts, Vibration, Three Wheeled, Powertrain, diesel engine, elastomeric mounts, MATLAB, Voigt Model, DOF model, kinetic energy

Synthesis and Experimental Characterization of the Potting Material to Reduce the Radio Frequency Signal Attenuation

2024-02-07T11:06:02+00:00

Radio frequency transmitting equipment used in the automotive industry, such as RADAR, GSM, GPS, and Bluetooth need to be encapsulated to protect them from variable operating conditions such as temperature fluctuation, dampness, vibration, and external environments. The encapsulation of these devices with polymeric hard potting leads to the attenuation of specific signal strength. In the present investigation, epoxy resin incorporated with various concentrations of hollow glass microspheres was prepared in order to reduce the effective thickness of solid epoxy material on top of the radio frequency transmitting devices and therefore reduce the signal attenuation. This investigation was related to epoxy composite preparation and enhancement of the signal transmission of potted radio frequency (RF) transmitting devices typically operating between 0.1 to 30 GHz. Morphology, structural characterization and thermal properties, of the prepared composites, were identified using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). Bluetooth Low Energy (BLE) analyzer and NRF connect application were employed to measure the signal range. The maximum signal range with prepared potting composites was found to be between 12-14 meters, whereas hard epoxy potting was found to be between 3-5 meters. The specific gravity and hardness of the epoxy-filled hollow glass microsphere (HGM) composites were investigated. The result signifies density and hardness of the composites decreased with the increase of HGB volume.

Keywords: Bluetooth, Characterization, Epoxy Potting, Encapsulation, Hollow Glass Microsphere, Potting, Radio Frequency, Signal Attenuation, TCU

Lessons Learnt: Ramifications in an Expeditious Project

2024-01-24T10:54:30+00:00

Program management and execution are key skills required in any organization. Project management practices, principles, people, processes, tools and techniques play a key role in the successful execution of projects. This paper will focus on the lessons learnt in the Power Generator set programs executed to meet the recent emission change levels. The programs started late, but had to meet the launch timeline for the emission change and also had to be made available in the market at the right time. The program was launched in the market at the right time, overcoming the challenge of meeting the short timelines, with added complexities on manufacturing location change and other scope of work. This paper tries to bring out the ramifications of running the program at a high pace. This paper will focus on the key challenges faced during the program and how the team effectively mitigated the challenges. This will give food for thought for future programs to meet any short project timelines requirement and meeting quality requirements. Though the team tried to compress activities and timelines, product reliability and the work content needed to meet reliability requirements were never compromised.

Keywords: Program management, Expeditious Project, Emission compliant product, information technology, Conflict Management, Change Management

Use of xDomain Vehicle Simulation for Electric Vehicle HV Battery Health Prediction

2024-01-02T12:31:25+00:00

A vehicle system comprises of various domain subsystems (e.g., Brakes, Steering, Thermal etc.,) components, elements, and the environmental factors with which it interacts. The vehicle usage or mission characteristics influence how the load are transferred from wheels to corresponding powertrain components which deliver energy. In today’s advanced electrified, connected & automated vehicle systems, the overall cross-domain interactions are very tightly coupled, and their detailed analysis is cumbersome. To predict component performance/Degradation over the life cycle it is necessary to estimate the real load conditions and the virtual environment is a key enabler. xDomain simulation serves this purpose which comprises multi-physics vehicle models capable of representing complex vehicle system architectures along with its interacting subsystems & components used for various system analysis under many test conditions. In this work, an Electric Vehicle model with all the elements relevant to Energy flow has been built along with the virtual road based on real driving information for 24 hours duration. High Voltage Battery operations are calculated for Quantity of Interest which would be used in a detailed HV Battery model for critical Battery health Prediction/Estimating.

Keywords: xDomain, Simulation, Electric Vehicle, battery health, battery voltage, HV battery

Solar Powered Proton Exchange Membrane Electrolyser for Hydrogen Production

2024-05-17T06:47:43+00:00

The production of hydrogen was explored in many ways such as auto thermal reforming, partial oxidation, biomass gasification, steam reforming, water electrolysis, Kvaerner process, thermochemical process and photo-biological process to utilize the high calorific value fuel for combustion in IC Engines for advanced transportation. In this paper, we have attempted the estimation of the production of hydrogen using the Proton Exchange membrane electrolyzer. The water splitting in Solar powered PEM EL is simulated and electrode kinetics is explained in detail. Scaling requirements for the production of 100 kg of hydrogen per day is presented.

Keywords: Hydrogen, Anodic reaction, Cathodic reaction, Platinum, iridium, PEM fuel cell

Space State Model of Lateral Vehicle Motion for Stability

2024-05-17T08:45:46+00:00

The lateral Motion of the vehicle is studied under the situations of steering, where the yaw control of the vehicle is focused on the stability of the vehicle under extreme steering conditions. In this paper, bicycle models for low-speed and high-speed operation are presented with emphasis on the kinematic model at low-speed operation and the dynamic model at high-speed operation. A state space model is developed with 2 dof and state space variables are presented for calculating slip angle and yaw angle. The parametric variation of slip angle and yaw angle is tabulated for various steering angles within the range of 110 to 28.560. A Python code was developed and simulated for under-steer and over-steer conditions depending on the corner stiffness of the front and rear wheels. The results were presented for further improvement of the model analysis with road banking angle and total vehicle model.

Keywords: Yaw control, front steer angle, rare steer angle, slip angle, yaw angle, state space model, Python Code

Evaluation of Drivers Seating Posture by REBA Analysis

2024-05-17T09:06:17+00:00

This study undertakes a comprehensive assessment of driver seating posture and ergonomic risks using the Rapid Entire Body Assessment (REBA) methodology. Thirty drivers from Telangana, India, without pre-existing musculoskeletal conditions, were analyzed to determine the ergonomic risk levels associated with their driving postures. Using photographic documentation and AUTOCAD software for poster angle measurement, the REBA scoring system highlighted areas of concern, mainly focusing on the wrists, trunks, and upper arms. Results indicated that most drivers (90%) fall into a medium-risk category, with scores ranging from 4 to 7, suggesting a significant need for ergonomic intervention. The remaining 10% exhibited lower risk levels yet pointed to the need for improvement. This study reinforces the need for ergonomic enhancements to reduce the risk of musculoskeletal disorders, suggesting interventions such as seat and control redesigns and educational programs to promote safe driving postures. The findings serve as an urgent call for improving vehicle design ergonomics to enhance drivers' occupational health and safety.

Keywords: Seating posture, Rapid Entire Body Assessment (REBA), AUTOCAD

Dynamic Analysis on a Sub-Scaled Physical Model of a 4-Ton Truck Composite Ladder Type Cassis

2024-05-17T09:46:46+00:00

Composites are materials created by combining dissimilar materials with a view to improve their properties or to create materials with desired properties. Advanced fibre-reinforced polymer composites have emerged as an important class of engineering materials for load-bearing applications with all-round properties for many engineering and social applications.

The automobile chassis is the basic framework where major systems like transmission, steering, suspension, braking, etc are attached to and supported by the chassis frame. When the vehicle travels along the road, the chassis is subjected to excitation from the engine and transmission system as well as due to the road profile. Due to these excitations, the chassis begins to vibrate. If the natural frequency of the vibration coincides with the frequency of external excitation, resonance occurs, which leads to excessive deflection and failure. In such critical conditions, the material of the chassis plays a key role in damping the vibrations. Fibre-reinforced composites proved to crave high specific strength and good damping properties.

The aim of the work is an experimental investigation of dynamic analysis of a sub-scaled model of a 4-ton truck composite chassis. In the present work, an attempt is made to develop E-glass/ Epoxy pultruded chassis frame.

Keywords: Excitation, Fibre Reinforced, E glass/ Epoxy, Pultrusion method

Sizing of an Electric Powertrain based on Urban Traffic Parameters and Hybridizing of a Two-Wheeler

2024-05-17T10:30:17+00:00

Transportation contributes to climate pollution, and reducing emissions is crucial to address the issue. Gasoline and diesel engines contribute to respiratory illnesses and early mortality. Researchers are focusing on performance-enhancing technologies like hybrid cars to reduce emissions and protect the environment. This project aims to size an electric drivetrain for urban environments and install it on a traditional two-wheeler. Real-world traffic data variables such as average speed, acceleration and average travel distance guide the effective sizing of the electric motor and battery pack. A control strategy has been developed, tested and successfully deployed on the vehicle. Complexities like the volume of space needed for battery pack and electric motor fitment location are evaluated for hybrid drivetrain architecture. A selected electric motor and battery pack is used to hybridise a conventional two-wheeler. The electric motor can reduce pollutants and fuel usage during high-traffic periods. Therefore, the overall usage of IC engines has been reduced, which results in the reduction of fuel consumption and tailpipe emissions of the vehicle.

Keywords: Powertrain, urban traffic, two-wheeler, transportation, fuel mode, electric mode, battery technology

Computational Analysis of Concept Autonomous Heavy Vehicle to Reduce Drag Using Shape Optimization Technique and Add-On Devices

2024-05-17T12:00:35+00:00

The design of heavy commercial vehicles plays a vital role in improving aerodynamic performance. Typically, conventional commercial vehicles have box-shaped driver cabins and standard trailer configurations leading to high fuel consumption. The streamlined flow around the vehicle will improve the aerodynamic characteristics and directly influence fuel consumption. As a part of technological advancement, the design of the autonomous vehicle with streamlined flow characteristics will give a highly efficient vehicle. The objective of this research work is to perform a computational analysis of the concept of autonomous heavy vehicles to reduce drag. Initially, to get streamline flow characteristics around the vehicle, the shape optimization technique is used with different design aspects. Further, various add-on devices such as boat tails and side skirts are incorporated into the vehicle trailer part. Based on benchmarking and market surveys, a typical conventional heavy commercial vehicle model is selected as the baseline vehicle model. Considering autonomous vehicles, the concept design of the vehicle is proposed using shape optimization techniques and add-on devices. To observe flow characteristics and to evaluate drag, the computational analysis is performed using a realizable k-e turbulence model at a speed of 80kmph for the baseline vehicle model and proposed concept autonomous heavy vehicle model. The result shows a low drag coefficient for the proposed conceptual autonomous heavy vehicle model as compared to the baseline vehicle model for the selected parameters. The overall reduction of the drag coefficient is observed at around 54%. Thus, the proposed vehicle design using autonomous technology can be used for efficient freight transportation.

Keywords: Flow characteristics, concept autonomous vehicle, shape optimization, drag coefficient, add-on devices

Editorial

2024-05-21T03:59:35+00:00

Dear Readers,

With the rapid advancement of technology and an increasing focus on sustainability, user expectations are evolving swiftly. For stakeholders in the mobility industry, from manufacturers to service providers, understanding and anticipating these expectations is essential for staying competitive in this dynamic market. Two fundamental aspects—reliability and durability—are key to meeting the high expectations of modern consumers and addressing the practical demands of the mobility ecosystem.

Electric vehicles (EVs) have captured both the public imagination and market share, driven by their environmental benefits, advancements in battery technology, and government initiatives. As EV adoption increases, the durability of both the vehicles and their supporting infrastructure will be crucial to maintaining consumer confidence and minimizing lifecycle costs.

The emergence of connected vehicles, which communicate with each other and with infrastructure via the Internet of Things (IoT), introduces new dimensions of reliability and durability concerns. Technology providers must prioritize cybersecurity measures, incorporating advanced encryption, regular software updates, and real-time threat detection to guard against vulnerabilities. Durable software architectures that can withstand continuous use and adapt to emerging threats are vital for maintaining the integrity and reliability of connected mobility solutions.

Effective fleet management is also essential for ensuring reliability. Regular maintenance schedules, real-time monitoring of vehicle health, and predictive maintenance technologies help extend the lifespan of shared vehicles. This not only reduces operational costs but also ensures reliable service for users.

Manufacturers are increasingly focusing on sustainable materials that offer long-term durability to reduce environmental impact. Innovations in materials science are leading to the development of composites and recycled materials that do not compromise performance.

This journal on mobility technology and its contributors provides valuable insights not only on reliability and durability but also on comfort, safety, and other sustainability aspects. I am confident that readers will find the articles in this ARAI journal useful for gaining insights into various aspects of mobility technology and advancing the automotive industry.

I extend my warmest wishes to each reader of this journal.