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Gupta A.K.,Vehicles Research and Development Establishment | Ramanarayanan C.P.,Vehicles Research and Development Establishment
Mechanism and Machine Theory | Year: 2013

Since multiple paths of power flow exist in many transmissions, an undesirable situation of power circulation can arise in the system which leads to high mesh losses and less overall efficiency of the system. The paper presents a detailed analysis of circulating power within a planetary gear transmission used for hybrid vehicles. The fundamental relations connecting torques, speeds and power flows for a general planetary drive mechanism, are derived from the first principles for kinematic and power flow analysis. The power flow relations are investigated and clearly defined for the analysis of circulating power within complex chains of planetary drives and they also permit an immediate derivation of the power flow in all inversions of planetary drives. This study contributes to the development of a methodology for the circulating power-flow analysis of a planetary gear drive with two inputs and one output. This approach is generic and an illustration is presented to demonstrate its applicability to a hybrid planetary gear configuration. It is found that circulating power depends on planetary gear ratios and speed ratio of two power sources. © 2013 Elsevier Ltd.

Gupta A.K.,Vehicles Research and Development Establishment | Kartik V.,Vehicles Research and Development Establishment | Ramanarayanan C.P.,Vehicles Research and Development Establishment
2015 IEEE International Transportation Electrification Conference, ITEC-India 2015 | Year: 2015

Hybrid electric vehicles are widely seen as potential solutions to the problems of exhaust emissions, fuel consumption and technical challenges to increase vehicle functionality. The present paper focuses on the design, development and performance evaluation of a parallel hybrid electric vehicle based on the concept of a new parallel hybrid transmission. A light pickup diesel vehicle is selected as a platform for hybridization because this category of vehicles consumes a lot of fuel. A prototype of the new transmission system comprised of a coupled planetary gear set, clutches and brakes is built. This transmission utilizes two planetary gear trains coupled for multispeed capability and, has the ability to operate two power sources and to control such power sources independently from one another. To demonstrate the practical applicability of the transmission and this hybrid configuration, one prototype vehicle is built integrating the new transmission system. Since lead acid batteries are available in Indian market, so these batteries are considered in the development. The prototype vehicle is tested on a chassis dynamometer and on test tracks. The acceleration performance of the hybrid vehicle is improved by about 25% over that of the baseline vehicle. An improvement of about 21% in the fuel economy of the hybrid vehicle is measured. The greenhouse gas emissions from the hybrid vehicle are reduced in proportion to fuel consumption. It is a fail-safe design. The new transmission system is proved to be a viable option for parallel hybrid electric vehicles in light duty applications. © 2015 IEEE.

Jagirdar V.V.,Vehicles Research and Development Establishment | Dadar M.S.,Vehicles Research and Development Establishment | Sulakhe V.P.,Vehicles Research and Development Establishment
Defence Science Journal | Year: 2010

Wishbone structure for double wishbone front-independent Suspension for a military truck application is presented. At present, the vehicle is equipped with rigid axle with leaf springs. There are two aspects that dictate the design of wishbone structure, viz. the path of relative motion between the constituents of the suspension system and the forces transmitted between them. Also, enhancement of mobility was made possible by maintaining the live axle in the system. A double wishbone, double coil spring with twin damper configuration was employed for this application. MBD Analysis was carried out using MSC ADAMS. A double wishboneindependent suspension has been designed for the front axle and has been successfully integrated with the vehicle. © 2010, DESIDOC.

Senthilkumar K.,Vehicles Research and Development Establishment | Chidanand M.,Vehicles Research and Development Establishment | Nijalingappa P.,Vehicles Research and Development Establishment | Shivhare M.M.,Vehicles Research and Development Establishment
Defence Science Journal | Year: 2010

Hydraulically-leveled platforms are required, to provide a leveled base for accurate leveling of high-rise masts and other vehicle-mounted communication devices. Design, development, and validation of one such platform on an 8×8, high mobility, wheeled vehicle is presented. The platform is a welded structure, designed to accommodate two ISO type shelters, and the shelters are secured to the platform at their four ISO corners using special twist locks. The leveling of the platform is enabled by actuation of four hydraulic cylinders bolted to the vehicle chassis. The concentrated type loading, resulting due to clearance maintained between the skids of shelters and the platform, and the loading pattern are the major design considerations. The other factors that have bearing on the design of platform include accommodation of variants of shelters, ease of operation of equipment mounted on the original chassis, and load distribution on axles, over-all height, ground clearance and departure angle of the integrated entity. Deflection and stress analysis of the platform structure using finite element analysis has been carried out for two types of shelter loadings. Limited track trials have been conducted at Vehicles Research & Development Establishment (VRDE) for assessment of structural integrity of the platform, and constructional and mobility aspects of platform-mounted- vehicle. Measurements of strain at critical locations, under-shelter loading, and while driving the vehicle at two different vehicle speeds on pave and cross-country tracks, have also been carried out for validation of design of platform. Details on problems faced during track trials, and the subsequent modifications carried out to the platform are also discussed. © 2010, DESIDOC.

Parihar A.S.,Indian Institute of Technology Bombay | Sethi V.,Indian Institute of Technology Bombay | Parikh P.P.,Indian Institute of Technology Bombay | Radhakrishna D.,Vehicles Research and Development Establishment | And 3 more authors.
SAE Technical Papers | Year: 2011

Suitability of the compression ignition engine for biodiesel fuel based operation has been discussed in several studies. However, studies focusing on the physical characterization of exhaust particulates from engine operating with bio-diesel blends are limited. This study characterizes the particulate emissions in terms of particle size distribution from a compression ignition engine operating on diesel and bio-diesel of two different origins namely Jatropha and Karanja in the form of 20% blends, as a function of loading. A ten-stage inertial impactor (MOUDI) was used to obtain particle size distributions. It was observed that particle mass concentrations of sub-micron particles are higher for higher loading conditions. Further, test results indicated that contribution of PM2.5 particles to the exhaust to the total particulate mass varied from 75% to 95% for the load conditions used in the study. Copyright © 2011 SAE International and Copyright © 2011 SIAT, India.

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