The RUF Standard: Some Preliminary Considerations
Palle R Jensen
At some stage in the development of dualmode systems, a standard must be defined. It must take care of at least the following parameters:
This task is a very difficult one if the Dualmode system is an Automated Highway System, where all vehicles are completely different from the start, but are equipped with electronic devices in order to make them work together in platoons.
Using a pallet solution is very easy from this perspective. All pallets would be built to the standard and different vehicles could be fixed to the pallet. For other reasons, I find the pallet solution to be impossible as a long term solution and will argue that the chicken-and-egg problem can be overcome via implementation of public transport as the starter system.
A better strategy is to define a platform and make the vehicle manufacturers create their vehicles based upon this common platform.
The strategy of RUF International is to develop and define the standard for these platforms and the guideways, but leave it to the car manufacturers and local entrepreneurs to create vehicles and guideways for the system.
The RUF standard has not yet been defined, but some conclusions are beginning to emerge from our development process.
Maglev will be excluded. It is far too expensive and for speeds up to 150 mph it does not solve any problems which cannot be handled via ordinary wheels. Linear induction motors are also excluded. LIMs are too inefficient and LSM are too expensive. Modern AC motors are very efficient and as easy to control as LSM.
The guideway will be a triangular construction. It is a very simple shape and it enables the vehicles to have an ideal propulsion and braking function via the top of the guideway. A triangular cross-section has a high torsional stiffness and a good ability to carry load. Its shape will not allow rain and snow to cause serious troubles. Once solar cells become cheap enough, the tilted sides will be ideal for collection of solar power. The visibility of a guideway per given height is smaller for the triangle than for a box shaped guideway since it is normally viewed at an angle from below.
The most probable dimensions at this time seem to be 85 cm wide and 58 cm high.
Switching will be based upon magnetic guidance via alternating magnetic fields from wires embedded in the road surface. This is a principle which has proven to be very reliable in the tunnel under the English Channel. Service vehicles have run more than 1.5 million kilometer at > 50 km/h magnetically guided and without any problems. The frequencies will be in the range of 5-25 kHz.
Power will be supplied via 2 sliding contacts connecting to 2 powerlines placed one on each side of the top of the guideway. The vehicles will need to have enough battery capacity to run 50 km on their own. The voltage on the power lines has not yet been decided. If fuel cells become available fast enough, this power supply may even be completely eliminated.
Communication between the guideway and the vehicles will probably be made via a leaky coaxial cable running along the top of the guideway. The protocol has not yet been defined.
These are some of the preliminary standards considerations which have come out of the first tests of the RUF system performed at the test track situated at the Engineering Highschool IKT in Ballerup outside Copenhagen, Denmark.
Last modified: January 28, 2001