Could Michelin’s Active Wheel truly transform the car?

Cars today have evolved and been refined to an extraordinary degree, but carmakers – and car designers – are still always looking for ‘the next big thing'. Yet despite a myriad of recent technical innovations, ask the man on the street what is the problem with cars of today, and he'll likely reply along the lines of "they all look the same". Mass production processes, packaging requirements and safety and regulatory constraints are just a few of the reasons why it is hard to make a car that looks truly different.

If anything is set to change that in the coming years though, technology still appears the most likely impetus. For more than a decade now, tire manufacturer Michelin has been working on a new technology it believes has the potential to truly transform the car. The Michelin 'Active Wheel' combines not only an electric drive motor, but also braking equipment and an 'active' suspension unit into the hub of a single wheel.

The hub-mounted electric motor isn't a new idea. One of Ferdinand Porsche's first vehicles – the 1899 Lohner-Porsche, was what would today be described as a hybrid-electric vehicle, featuring hub-mounted motors. Other companies such as PML Flightlink and Siemens are also working on electric hub-motors, but Michelin's critical innovation is to have packaged drive, braking and suspension within the hub. The active suspension unit replaces the mechanical set-up utilized in today's vehicles, with an electric suspension motor that controls torque distribution, traction, turning, pitch and roll – thus doing away with the conventional suspension arms, differentials, CV-joints, shock absorbers, and so on.

Having first shown the technology in 2004 as part of the 'Challenge Bibendum' Hy-Light concept car, it wasn't until the 2008 Paris motor show that the world got a real preview of the technology's potential impact on car design. Working in partnership with Michelin, Monaco-based Venturi previewed the technology in the Volage – a compact two-seat sports car concept, based on the chassis of its existing Fetish, but featuring a Michelin Active Wheel at each corner, and completely new bodywork.

"The engines [for the drive and suspension] in the wheel, gave me the opportunity to make a very particular design," says Sacha Lakic, Venturi's design chief. "I used this technology to justify the styling, but also, one could say the opposite is true." Lakic is alluding to the fact that the Michelin Active Wheel removes so many typical automotive design constraints that the designer almost needs to reintroduce some self-imposed rules. "So the other key design 'guideline' for the Volage was aerodynamics. It was absolutely necessary for me to give this idea that the car was designed by aerodynamic constraints. Therefore, all of the design of Volage is justified by just these two things – the Active Wheel, and the aerodynamics."

Asking where the influence of the Michelin Active Wheel is most apparent in the design, Lakic suggests: "The most impressive aspect of Volage is when you look at it from the back – it's just empty, there is nothing. And this is because of the Active Wheel".

Clearly, there are huge implications – both for cars, and car designers – with this technology. Not only could cars conceivably become lighter, and much more compact – but with fewer fixed hard points, surface language and material use could radically change – perhaps doing away with stiff, stressed metal altogether. While that might seem far-fetched, some university test beds utilizing in-wheel technology have shown how it could allow cars to fold up when parked, or even have soft skins.

Michelin is in the process of commercializing the Active Wheel, but whether Venturi will be the first to utilize it in a road car is a moot point. The Volage is planned for limited production in 2012, and Lakic is clearly hopeful that the technology will feature. "The relationship between Michelin and Venturi has been very close and collaborative. We spent a lot of time working with the Active Wheel team from Michelin on the original Volage, and there's a strategic agreement to make something happen going forward. For now, we are waiting for Michelin, to see if the Active Wheel is ready. There are a lot of tests going on, and we asked for a little bit more power – and at the moment it's going in a very positive direction."

Related Websites:
www.venturivolage.fr
www.michelin.com
www.michelinchallengedesign.com

By Joe Simpson