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| :''For the use of "unimodal" in mathematics and statistics, see ]'' | :''For the use of "unimodal" in mathematics and statistics, see ]'' | ||
| '''UniModal''' or '''SkyTran''' is a concept by ] for a 160km/h (100mph) ] (PRT) system that would use electric linear propulsion and a form of passive ] called ]. | '''UniModal''' or '''SkyTran''' is a hypothetical concept by ] for a 160km/h (100mph) ] (PRT) system that would use electric linear propulsion and a form of passive ] called ]. No protoype exists, and Malewicki has not as yet secured funding for any pilot project. | ||
| The Unimodal design calls for vehicles being suspended from an overhead track and aerodynamically streamlined. The proposed system would use ] to interact with riders. Passive magnetic levetation is a new technology still in development, and UniModal is the first to propose using it in a PRT system. | The Unimodal design calls for vehicles being suspended from an overhead track and aerodynamically streamlined. The proposed system would use ] to interact with riders. Passive magnetic levetation is a new technology still in development, and UniModal is the first to propose using it in a PRT system. | ||
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| The system is designed to have very few moving parts (for economic reasons), the main moving part being the vehicle itself. The promoters refer to the system as "solid state", however wheels are present for use during starting and stopping, the door moves, as well as any moving conveniences such as fans to air from heaters or air conditioning units. | The system is designed to have very few moving parts (for economic reasons), the main moving part being the vehicle itself. The promoters refer to the system as "solid state", however wheels are present for use during starting and stopping, the door moves, as well as any moving conveniences such as fans to air from heaters or air conditioning units. | ||
| == System details == | |||
| === Costs === | |||
| Projected estimates: | |||
| * Installation cost: less than $10m per mile <ref></ref> | |||
| * Energy cost: Between $0.01 ''to'' $0.02 per pod-mile <ref name="evworld"></ref> | |||
| * Suggested end-user price: $0.10 ''to'' $0.20 per pod-mile (about the cost of gasoline for a car) <ref name="evworld" /> | |||
| === Pods === | |||
| ] | |||
| Because SkyTran plans to operate at high speeds, the pods are designed to be aerodynamically streamlined. Vehicles with lower air drag use less energy and produce less noise. The pod is designed to carry two people in tandem (one behind the other) for decreased air drag. | |||
| Resting pods would sit on small wheels, but when the pods accelerate to above around 2 mph, the Inductrack could provide enough levitation to lift the pod off the guideway. After slowing to below 2 mph, the wheels would act as landing gear to support the pod. <ref name="LLNL"></ref> | |||
| The doors of the pod would not have handles (inside or out), but would open automatically. However, a door release mechanism would be on the outside of the pod to allow rescuers to open the door. | |||
| === Guideway === | |||
| Guideways would be mounted on poles about 30 feet above the ground and would be made of modular steel components, attached to cemented foundations. In the past, the company has estimated a possible $1 million per mile once in mass production. | Guideways would be mounted on poles about 30 feet above the ground and would be made of modular steel components, attached to cemented foundations. In the past, the company has estimated a possible $1 million per mile once in mass production. | ||
| The guideway is designed to accommodate a ''3D'' grid design. It is called ''3D'' because the guideway can be built under or over other things - especially other guideways. The main reason to have such a grid is to avoid intersections - guideways can cross over or under other parts of the guideway so that no stops are necessary - much like freeway overpasses allow the cars on the freeway to continue non-stop. | The guideway is designed to accommodate a ''3D'' grid design. It is called ''3D'' because the guideway can be built under or over other things - especially other guideways. The main reason to have such a grid is to avoid intersections - guideways can cross over or under other parts of the guideway so that no stops are necessary - much like freeway overpasses allow the cars on the freeway to continue non-stop. | ||
| Although, like most PRT, the inventor suggests a guideway grid, the UniModal design permits guideways to be used in any configuration - such as a linear route system (like most train routes). | |||
| === Decelerate - tracks, and brakes === | |||
| Like all PRT systems, before vehicles stop, they would exit the main guideway, then slow and then stop on a deceleration guideway. This is analogous to the way cars exit a freeway, rather than remaining on the road. This allows the main guideway to maintain a constant speed. The design proposes that vehicles slow down to 20 mph on the deceleration guideway before actually making any turn. | |||
| ] would be supplemented by an emergency brake with a maximum deceleration of 6 ]. The pods would have seatbelts resembling race car seatbelts - with a wider belt and an X shaped harness - to be safer in emergencies. | |||
| This deceleration rate was chosen in order to enable vehicles at 1-second headways to comply with rail safety standards requiring that a public transportation vehicle must be such a distance behind the vehicle in front of it to make a ''complete'' stop in that distance. Note that rail safety standards do not yet apply to PRT systems, and that this braking rate is considered unsafe for the general population by most authorities. | |||
| === Magnetic levitation === | |||
| The ] system would be the passive ] system. Passive maglev requires no direct power to levitate vehicles, rather the lift is caused by the movement of the vehicle over the coiled wire in the track. | The ] system would be the passive ] system. Passive maglev requires no direct power to levitate vehicles, rather the lift is caused by the movement of the vehicle over the coiled wire in the track. | ||
| Inductrack permits low magnetic drag. At 100 mph, a 700 pound vehicle requires 408 watts (0.547 ]) to overcome this magnetic drag. A 700 pound car-like vehical traveling at 100 mph would use about 4 times this much. For comparison, conventional cars (''varying between 2200 and 3500 pounds with ] of between 0.011 and 0.03'') traveling at 65 mph consume between 3000 and 13,500 watts in order to overcome the tire resistance (not counting air resistance).<ref name="LLNL" /> Putting this in perspective, tire resistance is significant at low speeds (say around 10 mph where a car might require around 7000 W to overcome air drag), but at higher speeds air drag becomes much more significant (say at 100 mph, a car might require around 60,000 W to overcome air drag). | |||
| == Envisaged trip == | |||
| A person would approach an ''entrance portal'', walk up the stairs, and get in the ready pod. One would tell (verbally) the pod where to go, and the pod door would close automatically. The pod would then accelerate forward and up along the acceleration guideway, and would then merge with the main guideway at 100 mph. The pod would travel toward the destination portal and would exit on the decelerate track, slow down, and presently stop at an ''exit portal''. The door would automatically open, and the person would get out and walk down the stairs. The pod would then close its door, and edge forward to wait in a line with other pods, all waiting for people to use the pod in front at the ''entrance portal''. | |||
| Pods would travel at up to 100 mph within cities. Trips between cities would reach 150 mph, increasing the estimated energy usage per mile by approximately 3 times (according to the ]). | |||
| The SkyTran designers suggest that providing a door-to-door taxi service would be the most economical way to provide for the disabled, thus indirectly satisfying any relevant laws or regulations. | |||
| ==See also== | |||
| ] is the generic term for a family of similar systems. | |||
| ==References== | ==References== | ||
Revision as of 07:11, 9 June 2006
- For the use of "unimodal" in mathematics and statistics, see Unimodal function
UniModal or SkyTran is a hypothetical concept by Douglas Malewicki for a 160km/h (100mph) personal rapid transit (PRT) system that would use electric linear propulsion and a form of passive magnetic levitation called Inductrack. No protoype exists, and Malewicki has not as yet secured funding for any pilot project.
The Unimodal design calls for vehicles being suspended from an overhead track and aerodynamically streamlined. The proposed system would use speech recognition to interact with riders. Passive magnetic levetation is a new technology still in development, and UniModal is the first to propose using it in a PRT system.
The system is designed to have very few moving parts (for economic reasons), the main moving part being the vehicle itself. The promoters refer to the system as "solid state", however wheels are present for use during starting and stopping, the door moves, as well as any moving conveniences such as fans to air from heaters or air conditioning units.
Guideways would be mounted on poles about 30 feet above the ground and would be made of modular steel components, attached to cemented foundations. In the past, the company has estimated a possible $1 million per mile once in mass production.
The guideway is designed to accommodate a 3D grid design. It is called 3D because the guideway can be built under or over other things - especially other guideways. The main reason to have such a grid is to avoid intersections - guideways can cross over or under other parts of the guideway so that no stops are necessary - much like freeway overpasses allow the cars on the freeway to continue non-stop.
The magnetic levitation system would be the passive Inductrack system. Passive maglev requires no direct power to levitate vehicles, rather the lift is caused by the movement of the vehicle over the coiled wire in the track.