Debraj Bhattacharjee | IIT Kharagpur (original) (raw)

Papers by Debraj Bhattacharjee

This research attempts to identify the significant factors, analytically, in connection with safe... more This research attempts to identify the significant factors, analytically, in connection with safety in automotive driving and to develop a conceptual model of the electronic controller for the vehicle using such knowledge. Every year millions of people, around the world, meet casualties due to road accidents and the average lives lost per year in India alone is to the tune of hundred and fifty thousand strong. Such accidents are attributed to driver’s fault, road condition, traffic environmental factors and faults in vehicle mechanism. Researchers have focused primarily on these factors since the other factor ‘weather’ is beyond human control. The above three factors or causes have been studied, in Indian context, in this work and a concept model of driver assistance system, involving speed control module, is proposed.

This work presents an ecodesigning and operating performance improvement methodology in series-pa... more This work presents an ecodesigning and operating performance improvement methodology in series-parallel Plugin hybrid electric vehicle (PHEV) in passenger car category, through optimisation of powertrain, considering gradeability overreaching rolling terrain. Designing involves consideration for power of prime movers and the geometric specification governing gear ratio, which is the teeth number. PHEV performance is measured in terms of various output characteristics, such as, fuel economy, emissions, vehicle weight, battery charge, maximum velocity and maximum acceleration etc. and such output indicators comprising both ecodesign and vehicle operating performance attributes, eleven in all, are considered. For optimisation, the design space is generated using NREL, ADVISOR simulator in accordance with Taguchi’s method. Multi-criteria optimisation is used to converge the aforesaid output indicators into a single one using TOPSIS, MTOPSIS, Grey Relational Analysis and their surrogate ...

This paper presents a methodological approach for formulating the clutching sequence associated w... more This paper presents a methodological approach for formulating the clutching sequence associated with an automatic transmission. Rank ordered clustering technique has been used to achieve the optimal clutching sequence which is compared with the present designs to show the reduction in the number of actuators thereby leading to a more compact gearbox design. The proposed transmission schematic or stick diagram aids in developing the gearbox layout design. Data with respect to actuation and gear shifting sequence has been retrieved from the available literature, including patent documents, and has been used in this proposed heuristics based methodology for modeling actuation sequence in a gearbox. The proposed modeling approach is simpler for designing gearbox and implementing it for automotive applications.

Smart Innovation, Systems and Technologies

This article presents a comparative analysis of possible combinations of three transmission syste... more This article presents a comparative analysis of possible combinations of three transmission systems, namely, Continuously Variable Transmission (CVT), Planetary Gear Transmission (PGT), and Dual Clutch Transmission (DCT), to carry out the comparative study of fuel consumption to deduce new gearbox architecture. Modern automotive industry is moving towards greener technology that leads to the introduction of the Hybrid Electric Vehicle (HEV) as electric motor has higher efficiency compared to an IC engine. Different combinations of available transmission systems, viz., CVT-DCT, CVT-PGS, DCT-PGS, and CVT-DCT-PGS are tested in a MATLAB/Simulink environment. From this experimentation, it has been observed that the topology of transmission architecture also influences the fuel consumption apart from the losses in power train. This experimentation utilized the advantages of combining multiple gearbox architecture to develop a new gearbox to achieve maximum fuel efficiency and thereby reducing the carbon footprint. A systematic analysis of multiple gearbox architecture enabled the development of topological layout to achieve desired transmission architecture.

Renewable and Sustainable Energy Reviews

Abstract Community Energy systems are predicted to emerge as a clean and sustainable means of pro... more Abstract Community Energy systems are predicted to emerge as a clean and sustainable means of providing last mile energy access to off-grid communities in developing nations like India. Interestingly, rate of deployment and sustainability of such systems are low due to lack of conceptual framework determining sustainability of community energy projects with respect to inherent grassroots barriers. There is a dearth of pertinent research studies providing best practices to project planners and decision makers for accelerated deployment and sustainable operation of community microgrids. This paper aims to identify the typical grassroots barriers and their relationship with corresponding enablers under seven broad dimensions with respect to solar, biomass and micro-hydro based community energy projects. Thereby, set of critical barriers and enablers is extracted by applying integrated multi criteria decision making approach to develop decision maps and conceptual framework for realizing sustainable community energy projects. The developed decision maps offer best practices to community energy projects’ stakeholders to ensure sustainable project planning. The conceptual framework establishes direct and indirect relationships among significant enablers and critical barriers while providing policy implications to decision makers and utilities for achieving Universal Electrification through clean energy sources.

FME Transactions

An approach for design simplification and improvement in power-flow efficiency of an automotive p... more An approach for design simplification and improvement in power-flow efficiency of an automotive planetary gearbox is presented in this article. Integrated CAD-CAE model, formed on stick diagram representation of geartrain operation, is developed for gleaning efficient gearbox configuration. A stick diagram for a three-stage planetary gearbox is a case exemplified here. CAE/simulation for dynamic analysis is conducted to determine deformation in geartrain. Powertrain model of the vehicle, Saturn-SL1, is selected from NREL ADVISOR. The power flow efficiency for each gear ratio is computed using DelCastillo's principle, and deformation is analysed to identify suitable gear ratios. It is observed that designing gearbox with five ratios yields higher efficiency than with seven. The developed model is tested on MATLAB, with New Europian Driving Cycle, to specify best operating range.Higher efficiency range is underscored, that is, driving in second through fourth gear. The proposed approach specifies driving conditions and efficiency while designing a gearbox.

International Journal of Vehicle Performance

This study presents an overview of control logic development for automotive transmission in both ... more This study presents an overview of control logic development for automotive transmission in both electric and non-electric powertrain. The control of automotive power transmission determines the shift quality that is attaining smoother shifting, leading to better drivability which rather important. The steady upswing of electronic and embedded systems has supplanted mechanical controls. The transition of actuation technology from mechanical to electromechanical type also propels the development of electronic controls in the vehicle. The electronic transmission control unit (TCU) governing automation of gear-shifting process in the transmission system, betters the driving experience due to improved shifting quality. There has been a rising demand for automatic gear shifting owing to its potential for uninterrupted gear shifting or also called power shifting. Gear shifting strategy and control are central to quality shifting process. Hence this work presents state of the art on controls for gear shifting and identifies the scope of further research.

Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics

The automatic transmission system is very crucial for the high-speed vehicles, where the planetar... more The automatic transmission system is very crucial for the high-speed vehicles, where the planetary or epicyclic gearbox is a standard feature. With the increase in design intricacies of planetary gearbox, mathematical modelling has become complex in nature and therefore there is a need for modelling of multistage planetary gearbox including the shifting scheme. A random search-based synthesis of three degrees of freedom (DOF) high-speed planetary gearbox has been presented in this paper, which derives an efficient gear shifting mechanism through designing the transmission schematic of eight speed gearboxes compounded with four planetary gear sets. Furthermore, with the help of lever analogy, the transmission power flow and relative power efficiency have been determined to analyse the gearbox design. A simulation-based testing and validation have been performed which show the proposed model is efficient and produces satisfactory shift quality through better torque characteristics whi...

Energy

This article presents an optimized series-parallel hybrid powertrain transformed from a conventio... more This article presents an optimized series-parallel hybrid powertrain transformed from a conventional vehicle using an analytical approach without changing the original chassis. The proposed approach is based on a many-objective hybrid powertrain model, which aims to optimize the vehicle weight, fuel consumptions, emissions, and performances. Three different Surrogate Assisted Evolutionary Algorithms (SAEAs) are introduced based on the improved Non-dominated Sorting Genetic Algorithm (NSGA III), Multi-Objective Evolutionary Algorithm Based on Decomposition (MOEA/D) and Multi-Objective Genetic Algorithm (MOGA) for optimization of powertrain components. Initially, the powertrain optimization is performed for Urban Dynamometer Driving Schedule (UDDS) driving cycle with 20% road grade. Thereafter, all the obtained Pareto solutions are combined, screened, and 78 best feasible design points are considered depending on the constraints imposed. Subsequently, 15 design points are randomly selected for validation in Federal Test Procedure (FTP) driving cycle without road grade. It is observed that NSGA III reduces the vehicle weight and fuel consumptions by 4.39% and 46.47% respectively. The powertrain energy efficiency is improved by 57.49%, and the engine is downsized by 40%. The contribution of this article is twofold. First, the many-objective simulation model for hybrid powertrain is developed. Second, SAEAs are implemented as optimization techniques for optimal component sizing and promising results are obtained.

International Journal of Ambient Computing and Intelligence

This research article attempts to analytically determine the factors, significant for safety, in ... more This research article attempts to analytically determine the factors, significant for safety, in connection with driving of automotives as well as to develop a conceptual model of the driving assistance system, using the knowledge about such factors. Millions of casualties due to road accidents, happen worldwide every year and the annual average of lives lost in India alone is about hundred and fifty thousand. The causes of such accidents are attributed to road characteristic and condition, driving faults, driving conditions or traffic environmental factors and defects or functional failure in vehicle mechanism. Studies have focused primarily on these factors without associating the ‘weather' which has been reported as in a work but as an isolated factor without including the above three. This work includes all the four stated factors in modelling the driver assistance system for automatic speed control with warning system module. Further, to predict accident rates in a particul...

Smart Innovation, Systems and Technologies, 2017

The use of windmill has revolutionized renewable energy generation for people in communities, res... more The use of windmill has revolutionized renewable energy generation for people in communities, residing in remote areas that are not connected to the power grid. The gearbox, comprising planetary gear assembly, in the wind turbine, is a critical component in the structure and hence due care is to be taken in determining the design safety factor. This paper explores different optimisation techniques for analysing computer aided simulation data for obtaining the highest Safety Factor based on failure analysis, using experimental data of multiple design variables. Several design optimisation methodologies are used, namely, Taguchi Robust Design, Response Surface Methodology and Soft Computing Techniques etc. amongst others. It has been observed that optimality values differ, sometimes significantly, with the optimisation approach. An accurate comparison would provide the information regarding suitability of using a particular optimisation technique.

Structural and Multidisciplinary Optimization, 2015

The paper presents a computational approach to predict the load withstanding capacity of a planet... more The paper presents a computational approach to predict the load withstanding capacity of a planetary gear assembly. The application of Taguchi’s Design of Experiment has been employed for obtaining a linear regression model to predict a nominal safety factor value, indicating the maximum applicable load of the gear assembly based on the chosen input parameters for reducing power transmission failure of the gear assembly leading to better performance during running condition. The application of this approach is to demonstrate the advantage of combining Taguchi’s method for Design of Experiment (DoE) with Computer Aided Engineering (CAE) to reach the desired solution.

International Journal of Vehicle Design

This paper presents a literature overview of factors, both internal and external, modelled for im... more This paper presents a literature overview of factors, both internal and external, modelled for improving the shift-quality in automobiles through the development of a robust electronic transmission control unit (TCU). Such robustness, designed with considerations of internal and external factors, are essential for safety and driving comfort. As automobiles are becoming more sophisticated, the application of electronics and embedded systems is increasing for different functional control system designs, including the gear-shifting mechanism. An automotive transmission system equipped with electronic or electrohydraulic actuators, controlled by an electronic control unit, provides clutch-less driving experience to the driver for the shifting operation. TCU is used for automatic speed and torque control in different driving situations, and reduces the human error in gear selection for facilitating safe and comfortable driving. In the development of such a mechatronic controller, it is critical to find a robust control strategy in the context of semi-autonomous vehicles.