TVA Gazelle - 4-wheel tilting car/bike hybrid
May 21, 2008 Globally, we are on the brink of a new commuting age; cars are too heavy, too inefficient, too dirty and too big to be viable in tomorrow's traffic-clogged cities - and motorcycles are too dangerous and too hard to ride to be a real option for many. Perhaps the solution lies in some sort of hybrid between the two - a car that's not much wider or heavier than a bike, with four wheels so it can support itself, a typical car-like control system AND the ability to tilt for stability in the corners. If Australian inventor Phillip James has his way, the internal combustion version of his "TVA Gazelle" tilting 4-wheeler will make well over 100mpg due to the inherent efficiencies in the vehicle's design - and while it's as incredibly agile in the corners as its name implies, the steering wheel has absolutely no connection to the front wheels due to the Gazelle's radical new steering and handling system. James is in contact with major manufacturers in India and China - both of which are in immediate need of this kind of vehicle concept - and believes that a production version should cost less than US$10,000. Amazing.
Around the world, traffic congestion, parking congestion, petrol prices and automotive pollution are increasing at an enormous rate - and as they increase, the economical and traffic-busting advantages of scooters and motorcycles encourage more and more people to go to two wheels. But with an increase in motorcycles comes an attendant increase in road trauma statistics; clearly, both the traditional car and the motorcycle are fundamentally flawed for the task of big-city commuting.
The rise of a new breed of tilting three-wheeler like the Piaggio MP3 platform is getting people thinking about broader options for the commuter - but the fact remains that the MP3 is scarcely less dangerous than a standard scooter, it's not enclosed to protect the driver from the weather, and like all bikes it has the ability to fall over if it's not ridden properly.
Revolutionary steering system opens doors for a car/bike hybrid
Australian Phillip James of TiltingVehicle.net is of the opinion that the fundamental problems with cars and motorcycles are flow-on effects from a very early and virtually omnipresent design decision - connecting the steering input directly to the front wheels. Steering a car in this way throws all the weight to the outside of the corner - only the width of the wheelbase saves the car from toppling over sideways in the turns. Motorcycles have the ability to lean into the turns, but the dynamics of countersteering to achieve the lean angle are complex for new riders, and the rider's control over the vehicle's tilt is completely reliant upon traction - lose traction, and you're out of control and in trouble.
Tilting 3- and 4-wheelers like the Carver, Phiaro and Venture are a step in the right direction, says James, but they still can't offer total stability because the steering is still directly connected to the steering wheel - so when traction is lost or the vehicle goes to topple under cornering forces, the driver is completely responsible for any corrective action; a fundamental issue with any vehicle that uses direct steering control.
James' solution is simple yet revolutionary - his narrow, 4-wheel TVA Gazelle concept vehicle connects the steering wheel directly and exclusively to the vehicle's tilt angle. The front wheels are effectively then completely free to dynamically respond to the vehicle's momentum and inertia, turning into the lean all by themselves and maintaining exceptional stability in corners.
Because the driver has no direct control over the direction of the front wheels, there's no way you can do the wrong thing in an emergency - in a low-traction or even a zero-traction situation, the wheels will naturally steer into a slide, effortlessly applying the same 'opposite lock' a champion rally driver would use to get his car back on track. There's virtually no way the Gazelle can overturn on a flat surface.
If the concept sounds a bit far-fetched, take a look at this video from James' tilting vehicle homepage. The three-wheel prototype in the video is theoretically even less stable than the four wheeler in development, but it steers very quickly, maintains excellent stability when cornering on dirt, and looks like a hell of a lot of fun to drive. It also features a virtually standard car control system, as is evidenced in a further video in which James puts two completely new drivers in the prototype to demonstrate how instantly comfortable and intuitive the vehicle is to drive.
The exceptionally stable dynamics and simple control system of the Gazelle platform open up the potential for an entirely new vehicle concept that's perfect for the new commuting age: narrow, light, enclosed, safe, exceptionally efficient, quick, agile little commuter vehicles that can seat a driver and passenger in a good degree of comfort, that require no helmets or safety clothing, that can be heated and cooled much more easily than a car, and with space for luggage.
Best of all, in terms of the Gazelle's commercial prospects, it's simple and cheap to manufacture, using easily available parts. James estimates that a simple commercial version, under the right manufacturing conditions, should cost no more than US$10,000, and that the Gazelle's fundamental design and dynamics advantages should make it an immediate seller in traffic-clogged countries through Asia and the subcontinent, with Western countries catching on down the track. "We don't think there's any point in manufacturing a vehicle that nobody can afford to buy," says James, "that won't solve any problems."
More than 100 miles per gallon - taking aim at the Automotive X-Prize
James is currently in the process of preparing a Gazelle prototype for an assault on the US$10 million Progressive Automotive X-Prize contest. The X-Prize competition will effectively be a race between a large number of alternative vehicles from around the world, with the added provision that if a vehicle fails to make at least 100mpg, or stay within very tight emissions and safety guidelines, it will be disqualified. All vehicles also need to be production-capable and priced to be attractive to the market.
James explains that the TVA approach is vastly different to the approaches of many major manufacturers, who he believes are throwing expensive technology at fundamentally flawed platforms in order to achieve the X-Prize goals; "Many of the other X-prize competitors are taking standard cars, and applying all this expensive technology to them to try to make them more efficient. I don't think that's the right way to go about it. We're going to try and prove that the internal combustion engine can do the job.
"The main focus for us is the efficiency of the fundamental vehicle form. The engine is less important, the platform can support hybrid or electric engines, but it's fundamentally more efficient than a standard automobile platform."
In order to prove this, the Gazelle will enter the X-prize with a largely standard single cylinder, fuel injected 350cc ATV motor. James expects a prototype to be ready for testing by December this year.
It's not often that a vehicle debuts with such revolutionary potential - let alone one that should be so affordable around the world. Phillip James and his colleagues at TVA should be very proud of their work, and we look forward to seeing the Gazelle take on the X-Prize field and moving towards production.