Ambarish Kulkarni

Design procedure for low cost, low mass, direct drive, in-wheel motor drivetrains for electric and hybrid vehicles

Direct drive, in-wheel motors are ideal for electric and hybrid vehicles because the packaging of the drivetrain is so simple, because drivetrain losses are eliminated, and because individual wheel control improves handling and safety. In applications where cost is not a constraint, e.g. solar car racing, direct drive, in-wheel motors are the norm. In-wheel motors are also regularly demonstrated in concept vehicles. However, in-wheel motors are not used for production vehicles because of their high cost and high-unsprung mass. This paper describes a project that addresses these issues through the use of a novel, multiple-airgap, axial-flux, switched-reluctance motor with optimized packaging and low cost electronics. The emphasis of the paper is on how to design the system as a whole.

Electric Vehicle Propulsion System Design

Today’s global community strives for a greener and cleaner environment, car manufacturers are given with the enormous task of coming out with more sustainable cars with lower carbon emissions. One of the more sustainable alternative fuel vehicles chosen by automotive manufactures is electric vehicle (EV). Currently emphasis by auto manufacturers is on development of propulsion which is low cost, light weight with optimal power outputs. In this research, major modifications will be conducted on a GM Holden Barina Spark CDX 2010 in order to convert it from a regular internal combustion vehicle into full EV propulsion. In this particular study, more specifically the modifications made on the components within the rear wheel hub and propulsion system will be analysed and looked upon in detail. This is to ensure with all the changes made to the car, the possibilities of failure of any of the drive train components are either minimized or diminished entirely to avoid any compromise on the safety of road users.

Architectural Proposals for Electric Vehicle Design

Due to global warming and depletion of fossil fuels, alternative sustainable fuel technology is essential. As a consequence of this need, many automotive original equipment manufacturers have started manufacturing electric vehicles (EVs) as sustainable, zero-emission solution. This paper evaluates different architectures for EV design to establish a preferred architecture. A detailed literature study is outlined to evaluate production and concept proposals of many original equipment manufacturers, student projects, and autonomous electric cars. The different architectural aspects of these designs, such as mechanical and electrical technologies, are discussed. Starting with initial schematics, a theoretical model is developed for each of the EV drive train architectures. The study uses advanced modeling techniques to compare these architectures. Different drive train architectures are compared in the contexts of functionality, operation, manufacturability, and modularity. The preferred architecture was developed using advanced tools such as virtual modeling to establish operational sequences for the components that make up an EV. In addition, product data management software was used as management tool to document changes during the architecture’s development. Recommendations and discussions on a selection of vehicle architectures are detailed along with those for a preferred architecture.Copyright

A quarter-car suspension model for dynamic evaluations of an in-wheel electric vehicle

Electric vehicles (EVs) are an alternative architecture in the automotive industry that provide reduced emissions. This research has developed a switch reluctance motor (SRM) in-wheel drivetrain for an EV. SRM drivetrains are cheaper and do not use rare earth elements unlike a permanent magnet motor (PMM). Conversely, the in-wheel SRM has a drawback of an increased mass on the suspension when compared with an equivalent power output PMM drivetrain. This situation results in an increased mass at the wheels; hence, a suspension analysis is required. This paper discusses the suspension dynamics evaluated using a quarter-car simulation of an in-wheel SRM EV and compares it to the internal combustion engine (ICE) vehicle. The simulation used step loads derived design scenarios, namely (1) sprung, (2) unsprung and (3) driver’s seat. Further Bode plot analysis techniques were used to determine the ride comfort range for the developed EV.

Virtual Tools for Safety and Ergonomic Evaluations of Electric Vehicle Architecture

Electric vehicles (EV’s) are alternative fuel technology in auto industry with wide acceptance across globe. This paper elaborates virtual methods used to as tool for safety and ergonomic evaluations of in wheel design using Switch Reluctance Motor (SRM). In our recent research, a unique design of in wheel design using SRM has been developed. Special advantages of this design include modularity, scalability, cost effectiveness, and easy installation. Easy installation of in wheel design architecture is one of the prime criteria, since it relates to changing of tyres in long runs. In the proposed passenger car, if work is carried out for maintenance issues, generally single operator (mechanic) dose tyre changing or wheel/brake servicing. Two validations are important, mainly safety of the operator; secondly design for assembly of motor, and tyre rims. As a part of this research, Virtual Reality (VR) based safety and ergonomic evaluation studies have been conducted for the in wheel design adaptations. The computational models and virtual modelling simulations using motion capture, Arena and EON reality mimicked live system environments, so as to validate effectiveness motor assembly and disassembly functionality using human as an interface.Initial phase consists of schematic representations of models to evaluate conceptualisation for different designs. Based on schematics, SR motor and rim tyre models were developed and interfaced in VR environment. In second phase, vehicle topology was reverse engineered using hand held 3D scanner and converted to metafile for full scale model development. In third phase, motion capture was used with 20 camera systems to video record the existing human movements and rigid body such as tyre to develop live environment. Finally all three phases were interfaced together in VR environment to evaluate assembly and disassembly functions. Based on the validation of these, designs were fine tuned for effective assembly functionality. The VR based safety and ergonomic evaluation procedures were used for demonstration of wheel assembly disassembly functions by single operator. Similar context can be extended to other automotive design evaluations, without substantial prototype costs for safety and ergonomic evaluations.Copyright

Innovative automotive design for improving safety standards

Car carriers are a type of semitrailer which exhibit Occupational Health and Safety (OHS) concerns due to falls from height during operations. This paper outlines research carried out on the car carrier sector to prevent hazard due to falls. A new design addresses OHS concerns of falls from height. Injuries are often caused by drivers working above 1.5 m height for loading- unloading of cars, moving decks up and down and strapping cars in. The new car carrier design excels in reducing the risk of injuries to drivers and represents a new bench mark for OHS standards in the heavy vehicle sector. The next step would be to transfer this technology to other similarly affected heavy vehicle sectors.