Lotus wins 2013 SAE World Congress Tech Award

The Lotus Evora 414E Range Extender Hybrid has been chosen by the Editors of the SAE’s Automotive Engineering International Magazine, for its design and engineering innovation, uniqueness, potential for “real-world” production application, and potential benefit for industry customers and end user.

414 engine

Kevin Jost, Editorial Director of Automotive Engineering International Magazine said, “The Lotus Evora 414E was chosen for the AEI Tech Award for its unique combination of a multimode virtual seven-speed shift schemel, torque-vectoring stability control, and energy and power management optimization schemes.”

Aslam Farikullah, Chief Operating Officer for Lotus said, “In one high tech vehicle, the Lotus Evora 414E encompasses all the key areas of Lotus Engineering’s expertise, and doesn’t just demonstrate the high level of technological advancements in our products, but is also relevant to the motor industry and applicable to the long term future of the car. We are delighted that the SAE have recognised this with such an important and prestigious award.”

Every year, the editors of Automotive Engineering International select, from among SAE World Congress exhibitors, the technologies they judge worthy of an AEI SAE 2013 Tech Award. Judging is based on level of design and engineering innovation, uniqueness, potential for “real world” production application, and potential benefit for industry customers and end user. The SAE 2013 World Congress will be held this year from April 16 to 18 in Detroit; and other highlights of the event are viewable online at www.sae.org/mags/aei/saewc.

The Lotus Evora 414E Hybrid concept showcases new developments in plug-in, range-extended electric propulsion, new electronic technologies to enhance driver involvement and the adaptability of the Lotus Versatile Vehicle Architecture (VVA).

The range extended electric drive of the Evora 414E Hybrid consists of two electric motors driving each of the rear wheels independently via single speed geartrain, integrated into one common transmission housing, thus enabling torque vectoring for stability control of the vehicle. Electrical power is stored in a lithium polymer battery pack which is optimised for energy density, efficiency and high power demand and mounted in the centre of the vehicle for stability and safety. Additional range is provided by the Lotus Range Extender engine, an optimised 1.2 litre, three- cylinder engine, designed specifically for series hybrid vehicles. The drivetrain is designed to combine astonishing performance with efficient, low emissions driving.

Driver involvement is enhanced by the incorporation of HALOsonic Internal and External Electronic Sound Synthesis technologies from Lotus and HARMAN, which provide sound contouring within the cabin and improve pedestrian safety outside the vehicle. Integrated with the HALOsonic technology, the Evora 414E Hybrid also showcases a brand new technology from Lotus Engineering, a sports mode that simulates a 7-speed, paddle shift transmission that combines exceptional driver involvement for a hybrid sports car and optimised energy recuperation.

The Evora 414E Hybrid has been designed to highlight Lotus’ innovative electric and hybrid vehicle technology without distracting from the pure sportscar character of the Evora.

  • 0-60 mph / 97 km/h in around 4 seconds
  • Total hybrid range of over 300 miles / 483 kilometres
  • Eco mode or Sports mode featuring realistic 7 speed paddle shift with energy recuperation
  • Next generation of Lotus and HARMAN intelligent pedestrian warning system, integrating the advanced
  • HALOsonic sound synthesis system with video technology.
  • Torque vectoring for improved dynamic stability
  • 152 kW (207 PS/204 hp) of power and 400 Nm (295 lbft) of torque

Geneva Preview: Lotus Evora 414E Hybrid

The 80th International Geneva Motor Show sees Lotus Engineering unveil the Lotus Evora 414E Hybrid concept, a high performance technology demonstrator with a plug-in series hybrid drive system and new technologies for enhanced driver involvement.

  1. 0-60 mph/97 kph in under 4 seconds
  2. Total hybrid range of over 300 miles/483 kilometres
  3. Eco mode or Sports mode featuring realistic 7 speed paddle shift with energy recuperation
  4. HALOsonic Internal and External Electronic Sound Synthesis
  5. Torque vectoring for improved dynamic stability
  6. Integrated glass roof and engine cover and interior concept from Lotus Design

Lotus Evora 414E Hybrid

The Lotus Evora 414E Hybrid, so-named because this latest environmentally-focused technology demonstrator from Lotus Engineering produces 414 PS (306 kW) of power, promises breathtaking performance from a highly efficient propulsion system. The concept showcases new developments in plug-in, range-extended electric propulsion, new electronic technologies to enhance driver involvement, the adaptability of the Lotus Versatile Vehicle Architecture (VVA) that underpins the Evora 414E Hybrid and a dramatic new roof system and interior concept from Lotus Design. Through all of these aspects it ultimately demonstrates the exceptional ability of Lotus Engineering to integrate and develop advanced technologies for exciting, efficient, high performance niche vehicles.

The range extended electric drive of the Evora 414E Hybrid consists of two electric motors driving each of the rear wheels independently via single speed geartrain, integrated into a common transmission housing, thus enabling torque vectoring for stability control of the vehicle. Electrical power is stored in a lithium polymer battery pack optimised for energy density, efficiency and high power demand, mounted in the centre of the vehicle for stability and safety. Additional range is provided by the Lotus Range Extender engine, an optimised 1.2 litre, three-cylinder engine, designed specifically for series hybrid vehicles. The drivetrain is designed to combine astonishing performance with efficient, low emissions driving.

Driver involvement is enhanced by the incorporation of HALOsonic Internal and External Electronic Sound Synthesis technologies from Lotus and Harman International, which provide sound contouring within the cabin and improve pedestrian safety outside the vehicle. Integrated with the HALOsonic technology, the Evora 414E Hybrid also showcases a brand new technology from Lotus Engineering, a sports mode that simulates a 7 speed, paddle shift transmission that combines exceptional driver involvement for a hybrid sports car and optimised energy recuperation.

The Evora 414E Hybrid has been designed to highlight Lotus’ innovative electric and hybrid vehicle technology without distracting from the pure sportscar character of the Evora. The solution is innovative, instantly recognizable, beautiful and sporty. It demonstrates Lotus DNA.

Dr Robert Hentschel, Director of Lotus Engineering said: “Innovation has always been at the heart of Lotus and is needed now more than ever. The Evora 414E Hybrid is the perfect demonstration of Lotus Engineering’s core competencies: lightweight architectures, efficient performance, electrical and electronics integration and driving dynamics. The technology demonstrator represents an encapsulation of the advanced technologies that Lotus Engineering continues to develop to overcome the current environmental challenges facing the automotive industry and showcases the future direction that the sector is taking and why Lotus Engineering is perfectly placed to lead the technological development in this area.”

The Drivetrain
For the Lotus Evora 414E Hybrid, Lotus Engineering has developed a highly efficient, high performance drivetrain system consisting of twin motors each limited to providing 152 kW (207 PS/204 hp) of power and 400 Nm (295 lbft) of torque to each wheel via independent, single speed, reduction transmissions integrated into a single housing, enabling torque vectoring dynamic control of the vehicle.

The vehicle energy storage system is made up of the latest Lithium Polymer battery chemistry providing 17 kWH energy storage capacity. The battery pack is optimised for energy density, efficiency and high power demand, with over 100 kW discharge capability.

The Lotus Range Extender engine provides 35 kW (48 PS/47 hp) of power at 3,500 rpm via the integrated electrical generator and features an innovative architecture comprising an aluminium monoblock construction, integrating the cylinder block, cylinder head and exhaust manifold in one casting. This results in reduced engine mass, assembly costs, package size and improved emissions and engine durability. The engine uses an optimised two-valve, port-fuel injection combustion system to reduce cost and mass and can be operated on alcohol-based fuels and/or gasoline. The generator converts mechanical energy to electrical energy to replenish the battery pack charge and provides additional vehicle range in a small light weight package. The generator is also used as a motor to start the range extender engine. The low mass of the range extender unit (85 kg) and compact package makes it ideal for the series hybrid drivetrain in the Evora 414E Hybird.

All the operation and management of the range extender engine, the power management of the batteries and motor control are controlled by Lotus’ electronic control units and software systems. Full energy management of all the operating systems is the key to maximising performance and operation while minimising energy consumption and CO2 emissions.

For everyday commuting journeys, up to 35 miles can be travelled using battery power. The battery can be charged overnight using a conventional domestic mains supply through a socket concealed by the rear number plate. This permits the vehicle to operate with zero tailpipe emissions. For longer journeys, exceeding the battery capacity, the highly efficient range extender engine is used as a generator to supply the motor with electrical power and top up the battery.

Lotus has used its own vehicle simulation tools to determine the size, capacity, power and performance of all the components in the drivetrain system to optimise the system operation. Overall this is far more energy efficient, weight efficient and cost effective than fitting the vehicle with a larger and more expensive battery, which for the majority of short journeys is a redundant weight, which increases energy requirements. With regard to the total lifetime CO2 emissions of the vehicle, including the energy required to manufacture and run it, the range extender solution has a lower overall CO2 footprint than a fully electric car of comparable performance and operating range running with a larger battery.

The Package
The Lotus Evora 414E Hybrid structure is the same award-winning, versatile vehicle architecture used on the Lotus Evora. The low volume architecture was designed with the upmost flexibility in mind. The Evora 414E Hybrid is a perfect example of how to integrate a compact packaged drivetrain, with excellent performance and range, while using this underpinning. The complete chassis has remained unchanged from the Evora which maintains the structural integrity and strength performance of the original car.

The structure progresses the Lotus ‘bonded and riveted’ technology with new and unique extrusions and folded panels, whilst providing production build modularity and lower cost repairs. The chassis has been designed for scalability so that it can be extended in width, length and height. The strength and stiffness of the low volume VVA chassis can be modified cost effectively by varying the wall thickness of the extrusions, without altering the exterior dimensions. The ability to lengthen or shorten extrusions with the option to tailor the chassis stiffness vastly increases the number of vehicles that can be developed from this vehicle architecture.

Driving Dynamics
The Lotus Evora 414E Hybrid offers exhilarating, all-round dynamic performance and takes advantage of Lotus developed torque vectoring dynamics. Torque vectoring, which is the capacity to generate different torques at each of the driving wheels, is particularly suited to electric vehicles and significantly reduces the conflict between stability and response.

A key benefit of separate motors to drive each rear wheel individually is that this facilitates a much higher level of vehicle dynamics control. Driving the wheels with different levels of torque can not only generate all the capabilities of a conventional ESP system using energy regeneration as opposed to brake application, but it can also actively drive each wheel forward at different rates, producing a turning moment at the rear of the vehicle in addition to the steering input.

This can be used to enhance low speed manoeuvrability and ease of parking but can also be used to produce a much greater level of straight line high speed stability. Incorporating lateral sensors the system also provides stability control capabilities and levels of steering response normally only associated with heavy and expensive rear steer systems. This can provide automatic correction of both understeer and oversteer characteristics. In addition, the standard method to provide high speed stability of designing the rear wheels to toe-in is not required as the torque vectoring system automatically provides this stability control, with toe-in increasing rolling resistance, lowering fuel economy and increasing tyre wear. Lotus‘ long history of active suspension control provides the core capability to develop this technology and provides extraordinary driving pleasure on the Evora 414E Hybrid.

Driver Interaction
The Evora 414E Hybrid provides less of a psychological step change for people familiar with high performance cars compared to other electric and hybrid sports cars. The car has a simulated paddle shift gear change offering ultra quick gear changes reminiscent of a dual clutch transmission, while actually single speed. This enhances the driver interaction with the vehicle and provides a driving experience similar to current internal combustion engine high performance sports cars. The Evora 414E Hybrid uses a column mounted paddle shift to simulate the gear change and a synthesised engine sound changes frequency with virtual gear selection. The drive torque is also modulated to simulate a physical feeling of a gearshift jolt.

The virtual gearshift simulation, like a conventional gearbox, is used to change the driving characteristics and response of the vehicle. The most significant aspect that this offers the driver is the ability to control the vehicle deceleration by simulating engine braking through a virtual downshift in gears. Unlike true engine braking, the Lotus system does not dissipate the energy of the moving vehicle through internal engine friction but uses the electric motors to regenerate the energy back into the battery. While many electric and hybrid vehicles provide engine braking, this is generally at a fixed rate or preselected rate. In some driving situations this can either be too aggressive, slowing the vehicle unnecessarily, or too light, requiring additional braking application. The Lotus system effectively allows the driver to select the appropriate level of regeneration by simulating stepping down by one, two or even three gears. The simulation of engine braking through both the gear noise change and the retardation of the vehicle is fully intuitive to a driver familiar with a conventional gearbox. The simulated gearchange capability can be selected for greater driving involvement or switched off for more relaxed driving.

The Evora 414E Hybrid uses the Lotus Engineering and Harman International developed HALOsonic suite of noise solutions. The first of which is Electronic Sound Synthesis. This generates engine sounds inside the vehicle through the audio system where it provides an exciting sports sound in line with the brand and nature of the vehicle together with a high level of driver feedback in an intuitive manner. In addition, it also generates sound on the outside of the vehicle through speakers mounted at the front and rear to provide a warning to increase pedestrian safety, which is especially important for electric and hybrid vehicles which can be difficult to hear at slower speeds.

There are four driver selectable engine sounds currently on the vehicle, two of which have been designed to have characteristics of a multi-cylinder conventional V6 and V12 engine. There is also a futuristic sound and a combination of a conventional engine and a futuristic sound, enhancing the brand identity of the vehicle as a step forward in electric vehicle design.

The addition of this Lotus patented simulated gearshift concept not only provides for an exciting and involving driving experience that customers would expect from a Lotus, but also enhances the driver’s control of the vehicle while providing the capability for more efficient operation through a greater use of energy regeneration.

The Design
The distinctive colour scheme and ‘floating’ roof have been carefully designed to accent the cars electric vehicle technology whilst complementing the iconic lines of the Evora.

Copper, a colour often associated with electrical systems, has been chosen for the car’s exterior and interior. A contemporary satin finish paint is complemented by electrical circuit inspired graphics that highlight the car’s key feature lines and the unique glazed roof panel. The newly extended glazed zone integrates seamlessly with the existing forms of the Evora whilst showcasing the key components behind the hybrid and electric vehicle technology.

The signature copper theme is consistently carried throughout the car from the dramatic seat stripes and instrument panel inserts to the copper callipers that nestle behind the carbon grey forged wheels. Inside the cabin a sense of quality and richness has been created by carefully juxtaposing the different tactile qualities intrinsic to leather, Alcantara and metal.

[press release from Lotus]

Lotus Range Extender Engine Revealed

The Lotus Range Extender – designed specifically for the new breed of highly efficient series hybrid vehicles.

lotus-range-extender-engine

Lotus Engineering, the world-renowned automotive consultancy division of Lotus, unveils its Range Extender engine at the 63rd Frankfurt International Motor Show. In a series hybrid vehicle, the Range Extender engine is attached to an electricity generator and provides a highly efficient source of energy to power the electric motor directly or charge the vehicles battery. The battery can also power the electric motor which enables the design of a drivetrain that has low emissions, optimised performance and acceptable range.

The Lotus Range Extender engine features an innovative architecture comprising an aluminium monoblock construction, integrating the cylinder block, cylinder head and exhaust manifold in one casting. This results in reduced engine mass, assembly costs, package size and improved emissions and engine durability.

The three-cylinder 1.2 litre Range Extender engine is optimised between two power generation points, giving 15 kW of electrical power at 1,500 rpm and 35 kW at 3,500 rpm via the integrated electrical generator. Its low mass of 56 kg makes it ideal for the series hybrid drivetrain configurations for which it is designed. The engine uses an optimised two-valve port-fuel injection combustion system to reduce cost and mass and, in line with Lotus Engineering’s extensive research into renewable fuels, can be operated on alcohol-based fuels or gasoline.

For successful market uptake of series hybrid vehicles with acceptable driving range, vehicle manufacturers must overcome the challenges of high vehicle cost. The Lotus Range Extender engine not only offers the advantage of a cost effective design, but also its high efficiency and low mass will enable the downsizing of expensive batteries whilst maintaining vehicle efficiency and range. The engine has been designed using production methodologies and the parts procured from low volume potential production suppliers, offering a fast route to market for original equipment manufacturers wanting to source a dedicated range extender for series hybrid vehicles.

Paul Newsome, Managing Director of Lotus Engineering said: “As the world changes, Lotus Engineering continues to change with it, continuously developing solutions for more sustainable transportation. The Lotus Range Extender engine is another example of Lotus Engineering developing new technologies for efficient performance, this time in the area of series hybrid vehicles. The engine concept we have created with its optimised combustion and compact, low mass, low cost construction is a clear demonstration of the expertise and progressive approach Lotus takes for its own research and for its clients.”

The Lotus Range Extender engine has been developed as part of the ‘Limo-Green’ project funded by the UK’s Technology Strategy Board, a collaboration between Lotus Engineering, Jaguar Cars Ltd, MIRA Ltd and Caparo Vehicle Technologies, demonstrating a large, lightweight, prestigious executive saloon with less than 120 g/km CO2 emissions.

Simon Wood, Technical Director of Lotus Engineering said: “Most series hybrid vehicles that are currently being developed will use adaptations of existing, conventional engines which are therefore compromised in the efficiency that they can achieve, designed as they are for a wide range of operating conditions. Designing the Lotus Range Extender purely for use in series hybrids has allowed us instead to develop an optimised engine that has high thermal efficiency, low fuel consumption, multi-fuel capability and a 35 kW peak output from a 1.2 litre, low cost architecture over the precise operating range required by a series hybrid drivetrain.”

Technical details:

Technical specification of the Lotus Range Extender engine

General

1.2 litre 3-cylinder with 2 valves per cylinder, SOHC

Belt driven

Construction

Monoblock with Integrated Exhaust Manifold

All aluminium

Balance shaft (optional)

Direct-coupled generator

Bore and Stroke

75.0 mm x 90.0 mm

Compression ratio

10:1

Maximum power

35 kW (47 bhp) at 3500 rpm via integrated electrical generator

Peak torque

107 Nm at 2500 rpm

Maximum BMEP

11.2 bar

Maximum Engine Speed

3500 rpm

Fuel System

Port fuel injection, Lotus EMS

Fuel

95 RON ULG / ethanol / methanol

Dry weight

56 kg


Key features of the Range Extender engine in detail:

Monoblock

The Range Extender features a novel engine architecture incorporating a monoblock construction that blends the cylinder head and block together eliminating the need for a cylinder head gasket, improving durability and reducing weight. Approximately 17 parts are eliminated using this approach and the water jacket is better optimised.

Integrated Exhaust Manifold

Lotus Engineering designed and developed a new advanced cylinder head design featuring an integrated exhaust manifold. The production-ready technology can significantly reduce manufacturing costs, emissions and weight. An integrated exhaust manifold has potential to:

o Reduce parts count: 18 fewer components resulting in lower inventory, production, logistics and aftermarket costs

o Weight reduction: total system mass reduction resulting from elimination of separate exhaust manifold

Improved engine durability

Generator

Attached to the engine via the crankshaft, the generator sustains vehicle operation beyond the range provided by the batteries.

Additional Benefits

The Lotus Range Extender engine generates a reduction in emissions through faster light-off of the close-coupled catalytic converter with a reduction in heat loss between the exhaust port and catalyst inlet. Engine operating range is optimised to deliver more efficient running, which also aids underhood thermal management.

Utilisation of the monoblock construction results in an assembly cost reduction, while there is also a reduced catalyst loading requirement because less heat is lost on engine start-up between the exhaust port and catalyst inlet.

Increased vehicle integration flexibility is achieved because of the reduction in mass and the reduced package size leads to reduced space requirements. Particular emphasis has also been placed on the coupling of the generator and NVH signature.