Revole and Emerald Automotive partner to build the EA t-001

Revolve and Emerald Automotive

partner in joint light-weight commercial vehicle

The t-001
in the Revolve workshop
The t-001 Light Weight Vehicle (LEV) – a Range Extended Electric Vehicle (REEV)

In less than 18 months, Revolve and Emerald Automotive built two clean-sheet ground-up new vehicles as proof-of-concept lightweight hybrid delivery vans with advanced telematics as part of a TSB initiative to promote UK businesses.

Early Concept DesignsEarly concept discussions between Andy Tempest from Intelligent Energy, whose brain child is now realised as the t-001, and Paul Turner from Revolve sowed the seeds of a plan to build a light-weight diesel-electric series hybrid. Government funding in the shape of a TSB initiative grant gave the green light to the project, which was to involve mainly UK businesses for the major technology components with an exploitation plan to volume production.

Revolve engineers, drawing heavily on their extensive prototype building expertise, drew up the concept designs for the advanced light-weight chassis, composite body panels, powertrain layout and the ergonomics of the interior design including an ergonomic prove-out buck to verify the CAD designs for the new H-point which included forward vision, rear view vision, steering wheel, seat and pedal positioning.

Working within a team of engineers from Ricardo, Evo Electric, Axeon, Penso, RDVS and partners Intelligent Energy,rear axxle layout the Revolve team laid out the basic chassis including powertrain and battery concepts, interior design and exterior panelling. These were then passed on to suppliers for detailing, before the two vehicles came together in Revolve’s Brentwood workshops.

Extensive weight analysis including a weight BoM, weight distribution matrix and finite element modelling of the whole vehicle allowed the Revolve team, led by Principal Design Engineer Steve Pegrum, to optimise the various components to achieve the lightest weight possible within the project.

Preliminary energy consumption analysis by the powertrain team, headed up by Principal Powertrain Engineer Trevor Jasper, determined the parameters of battery voltage, charge capacity, drive layout and control systems which would allow the vehicle to meet its design objectives. These were as varied as gradeability (starting on a slope fully laden), range on electric mode only, acceleration and of course maximum speed.

t-001 General layoutSubsequently, these assumptions were refined during the development phase and then extensively modelled by Ricardo to provide predictions of the vehicle range and performance over not only the regulated emissions cycles (European and Federal) by also over industry-recognised Hyzem cycles. These Hyzem cycles, as opposed to the European Emissions Cycle, simulate much more real-world cycles of Urban, Extra Urban and Motorway/Autobahn driving patterns which give better real-world measures of range for electric and hybrid vehicles.

The diesel engine was mapped on the Revolve dynamometers with the NIRA controller to optimise its engine-out emissions fuel economy and NVH with unique strategies written specifically for this hybrid installation.

Ricardo performed several iterations of the model analysis as data from the various test phases including engine emissions and fuel efficiency from testing at the Revolve dynamometer facility and the battery performance from tests at Axeon became available.HV Circuit Package Layout

To address the complexities of the hybrid design, develop the High Voltage (HV) system, and to prove out various charging and discharging strategy scenarios, Revolve built a “lab car” in their engine dynamometer facility.

The “lab car” proved to be an invaluable tool during the development as it allowed the team to evaluate the generator and traction motor including the 470Volt battery and inverter systems as well as assess various concepts in the high voltage systems which were new to the team. Various theories of operation and control were parameterised and evaluated ahead of the actual vehicle build.

All Revolve and Intelligent Energy personnel were given extensive safety training in handling HV systems for use in the workshop and the test cells.

The concept vehicles’ advanced telematics were developed by Ricardo. The ultimate goal of the telematics system is an “artificial horizon” of driver route choice including information on potential gradients, possible low- and zero-emission zones, traffic and urban areas which feed into the vehicle controller allowing for optimisation of the battery usage and minimum fuel consumption when combined with current information about the recent route, range, usage, battery temperature and current ambient temperature.

cooling schematicSignificant engineering effort went into designing the powertrain installation and cooling systems and their integration into the vehicle’s heating and ventilation requirements. By feeding the cooling fluid for the traction motor and its inverter through the range extender engine, waste heat is fed to the engine and cabin when cold which reduces warm-up time and emissions from the engine. Similarly, waste heat from the range extender is fed to the cabin if required before finally going into the radiator.

Uniquely, the battery has a heat exchanger with the cabin air which helps maintain the battery at its optimum temperature, which, coincidentally is pretty much the same ambient as the driver requires. Thus, waste heat is utilised as much as possible, maximising the efficiency of all the systems in the real world, not just for the homologation test cycles.

The vehicle is still equipped with AC and additional heating to ensure it fulfils requirements for ambients as diverse as southern Spain to northern Finland.

The first two prototypes have successfully completed all development testing to date with no major issues and have been used as demonstrators to press and investors alike. As part of the TSB funding for these vehicles, an exploitation plan showing a realistic route to volume production has been meticulously developed and extensively vetted.

 the t-001 in Bond street in the Future Car Challenge

For more information, please contact Paul Turner at Revolve on +44 (0) 1277 261400 or email paul.turner@revolve.co.uk