F2010B051
Deakin Universities Model D3 - a Vehicle that Combines the Best of 2 Worlds
Motorbike riders are 34-times more likely to die in a crash compared to car drivers per km travelled (Source: 2006 Motorcycle Safety Plan, NHTSA). Safety risks together with special skill requirements and comfort issues are the main reasons why motorbikes represent only a fraction of all vehicle sales. Deakin University is developing a revolutionary cross-over fun vehicle with ultra low fuel consumption and emissions. This new vehicle generation combines the best of two worlds: the affordability, size and fun of a scooter together with the safety, comfort and easiness to operate of a car. The result is a vehicle that is even more fuel efficient than a car or even a scooter. Various tilting cross over vehicles have been presented over the last decade that were trying to automate the tilting control of narrow vehicles to make them safer. Examples of these concepts are the Carver, Clever and in a way the MP3. The problem with these concepts is that they either require very complex and therefore expensive tilting control systems so that the vehicles are not price competitive compared to low cost micro cars, or the tilting control is only semi automatic so that typical car advantages - comprehensive safety features like roll over protection or comfort features like full weather protection including heating and cooling - can not be provided. Deakin's approach is quite different to these: it started with an in-depth benchmarking study of existing concepts which identified the typical strengths and weaknesses of these concepts. In a critical second step a new concept was created that addresses most of the weaknesses of existing tilting three-wheelers in a holistic approach by setting clear priority rankings for the vehicle targets. The priorities were set in the following order: Safety, affordability, fun and efficiency. Safety like a typical car is achieved by using typical car like features (seat belts, roll over structure, crush zones, air bags), similar as the Carver but with a view exceptions: The SafeRide(TM) tilting control system is an passive system that involves the driver in its feedback control system. That means that the vehicle has typical scooter like steering characteristics, steering is initiated through counter-steering. Another safety critical design feature is the crush zone between the two front wheels which is not possible with only one front wheel or with the powertrain positioned between the front wheels, as the powertrain can't absorb a lot of energy due to its structural stiffness and density. The passive tilting control system is quite simple and therefore makes the vehicle very affordable. Another advantage of integrating the human balancing senses in the feedback control of the tilting system is that the system kicks in slightly after the human balancing reacts. In some instances that can generate the typical adrenalin thrill know from riding a bike. This fun factor is quite common with many trend sports like mountain biking, surfing, roller-skating, snowboarding, or skateboarding. It also makes the vehicle safer as the adrenalin is produced after reaching a semi-stable driving condition that is controlled by the vehicles tilting control system, but before the vehicle reaches an unstable driving condition that can not be controlled by the vehicle but only (eventually) by the driver - if he is got the required driving skill and if he is alert enough. Efficiency superior to most cars and scooters is achieved by the aerodynamics of a fully enclosed body structure in combination with the small frontal area of a typical scooter and the droplet shape which we call the "tear of joy shape" enabled by the relatively wide front with 2 wheels and the very narrow tail with only one rear wheel. The passive tilting system also contributes to the extreme efficiency as the system only draws some small electrical power for the electronic control unit. Another feature is a low cost exhaust recovery system which could be the subject of another paper.. The paper will discuss key elements of the vehicle development process like the benchmarking and the critical holistic approach including the priority setting, together with economical considerations that are crucial for commercialisation. Some of the critical features like the SafeRide(TM) tilting control system will also be explained.
This abstract is supplemented by a PDF, which can be viewed here.