GB2399328A

GB2399328A - Elevated transportation system

Info

Publication number: GB2399328A
Application number: GB0305522A
Authority: GB
Inventors: Robert Ennals
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-11
Filing date: 2003-03-11
Publication date: 2004-09-15
Also published as: GB0305522D0

Abstract

The system, for passenger and freight transportation, comprises an elevated guideway 1, and vehicles 4 suspended from said guideway, and having the capacity to lower themselves to ground level in order for passengers and freight to be loaded and unloaded at specific locations 7. Vehicle landing places are shared with normal pedestrian walkways. In order to avoid safety issues with a vehicle landing in a pedestrian area, the descent of said vehicle to ground level is controlled by a human operator, indicators, e.g. by visual means (flashing lights) or an audible signal. The system is a network of guideways with vehicles computer controlled to prevent collisions. For vehicles ascent/descent at the specified locations 7, the vehicle 4 grips a vertical guide 6 on a guideway support post 8 by means of grabber units 13.

Description

Elevated Transportation System This invention generally relates to the

field of transportation and more particularly to overhead guideway systems, for example in which a payload is suspended from a motive unit travelling within an overhead guideway.

Such Lransportali<.,n systems can be used to transport both passengers and goods between a plurality of destinations connected by the aforementioned overhead guitleway.

Embotlbilents of the hvcntion relate in particular to the t'ield of Personal Rapid Transport (PINT). PRT systems comprise a large number of small, personal, automatically guidetl vehicles, and a large number of closely spaced stations. Vehicles are able to move between arbitrary stations at arbitrary times, al the direction of the occupy.

Transportation systems have typically been divided into two groups: Mass transportation systems consist of large, shared vehicles, transporting a number of unrelated peopic betwocn a small number of stops, travelling along fixed routes, at infrequent scheduled tones. Examples of mass transportation systems include rail and buses.

Personal transportation systems consist of small, personal vehicles, controlled by the otcupanis. Such vehicles can travel between arbitrary locations, at arbitrary times, accortlino to the wishes ot the occupants. The most common cxurnple of such a system is the car.

()ne major weakness of pcr-sonal transportation systems is switching. The vehicles in the. . system move in a shared space, and need to avoid coming into contact with each other. : If several streams of vehicles merge at a junction, then it is important that the vehicles be controlled carefully so that no vehicles collide. At such junctions, the throughput of a personal transportation system is limited by the speed at which vehicles can be safely switched. If the vehicles are controlled by human operators (as in the case of conventional automobiles) linen the throughput of the system is limited by the ability of the human operators to safely control their vehicles. As more vehicles enter the system anal the load <ins the system increases. vehicles will need to slow down in order to safely avoid each other. This can quickly lead to congestion.

Mass transportation systems avoid this problem by switching large numbers of people at once, thus simplifying the switching process. However this is done at the cost of no longer allowing passengers to select the time and route of their journey. It also causes passengers to lose a degree of privacy, as they must share a vehicle with people whom they do not know.

Personal Rapid Transit systems aim to achieve the freedom and convenience of personal transportation systems such as the car, while also achieving the throughput and efficiency of mass transit systems such as the train. This is achieved by having personal vehicles that arc controlled automatically by a computer. Computer control allows vehicle switching to take place at much higher rates. Not only can a computer compute vehicle paths Paster than a human, but it can also be aware of the future movements of other vehicles in the system. As an example, if two streams of traffic are merging, then each stream of traffic can be aware of what vehicles are in the other stream, and arrange to leave gaps lor them in advance, thus,tilowUlg the merge to take place without either vehicle stream slowing clown.

Automatically controlled vehicles would be unsafe if used on normal roads as, while they know the future behaviour of other such vehicles, they are not aware of the future hchaviour of passenger controlled vehicles, or of pedestrians or animals. PRT systems thus typically place their vehicles on a separate guideway which will norTnally be raised. so as to allow normal traffic to pass underneath, and to prevent pedestrians from wandering onto the guicleway.

There is much prior art for PRT systems. US Patent No. US3,937,147 describes the basic concept. Many patents describe plausible track designs, steering designs, and control systems. Examples include the tallowing US patents: US3,946,974; IJS4,671,185; US5,()74,22(); US5,1()8, 052; US6,202,566.

Despite the large amount of prior art, very few PRT systems have been implemented on a large scale. The main reason t'or this is cost. If a PRT system is to be truly effective, it needs to have a very large number of stations. In order to be truly comparable to a car, stations should be spaced at intervals of around 5()m or closer throughout the majority of the area that the system is installed. If the guidcway is raised above the ground. lUcn it is necessary to have some way lo move passengers between the level of the ground and the elevalccl level at which the vehicles move. Most prior art systems have achieved this by having raised stations. Such stations must, at the very least, contain stairs, and, if disabled access, goods access, or trolley access is to be allowed, an elevator must also he provided. A station also needs to have some form of platform, and barriers to prevent passengers from falling to the ground. All of these elements serve to make stations large, unsightly, and expensive, making it impractical to install them h1 the density required to make a PRT a viable replacement for the automobile.

The SwedeTrack Skyway system reduces this problem by providing the ability for vehicles to lower themselves to the ground. If vehicles are to lower themscives to the grouncl,1heT1 two problems must be overcome. Firstly, the vehicle must not descend on top of an obstruction such as a pedestrian, animal, or wrongly parked car. Secondly, the vehicles must remain stable while descending. They must not be allowed to swing from side to side, for example as a rcsul1 of wind. Skyway solves the stability problem by using a scissors a'-raTlgement of supporting bars; however this is complex, heavy, and likely to still leave the vehicle relatively unstable.

Skyway solves 1hc safety problem by having vehicles descend into walledoff landing places which can only be entered when a vehicle has landed; however this prevents the landing place being part of a pedestrian walkway - which is very important if pavements are narrow. It also requires the landing place to be designed to fit the shape of the vehicle, requiring either separate landing places for different vehicle types, or strict limits on the sizes of vehicles. A further problem is that walled- off landing places are visually intrusive.

Several prior art disclosures have explored the idea ol lowering passengers to the ground as an emergency exit ncchanism. US parent US5, 209,435 describes a system in which a vehicle Nay lower a small escape pod to the ground in an emergency. In this system, it is only a small pod that is lowered lo the ground rather than the entire vehicle.

Additionally, this pod can be used only for emergency exits, and not for normal loading and unloading.

Various designs for cargo movement systems include an elevated unit which travels along a guideway and which can raise and lower cargo items that are suspended from below il. (see' for example, US4,750,429, which describes horizontal and vertical guideways and a mechanism fOT moving between the two and US 4,372,452, which cicscribes a transfer hoist for disabled people). Such systems are frequently used in docks. on building sites. and within Factories but they lack adequate human and conputcr control. In addition, such systems are not intended for use as general transportation systems, and only move payloads over a small-scale controlled area.

So called "Dual Mode" vehicles behave like normal automobiles while on roads, but can be connected to a PRT guideway, at which point they become controlled by a central computer but no dual mode PRT system allows a vehicle to lower itself from an elevated track to the grouted (see, for example, US6,435,100, US5,592,883, t15.S,289,778, US5,22(),870. t5S5,138, 952, US5, 138,775,227, US5,029,665) Described herein is a system, in particular a personal transportation systcTn, that allows vehicles lo lower themselves to the ground in order to load and unload, but reduces the need lor landing places to be fenced off by arranging for the descent of a vehicle to the ground to he controlled by a human operator. Just as it is considered safe for a human operator to park an automobile in a parking space. it should be considered safe for a hunran to land a vehicle hi a landing place - provided they have a good view of what they arc doing.

A hybrid between computer control and human control is described in which a computer controls the vehicle when the vehicle is moving along the guideway, and ihlcractirig with other computer-controlled vehicles, preferably such that said vehicle does not come into contact with other said vehicles while travailing along said gateway.

A human operator controls the vehicle when the vehicle is landing, and interacting with humans and unpredictable obstacles. The human operator controlling the landing of the vehicle can be either a passenger, an operator al Demote location, or a human operate at flee landing place.

it is handed than it the vehicle is cal-yir,g adult, sighted passengers, linen the descent ol the vehicle be directed by the adult in charge of the vehicle. If the vehicle is carrying goods, children, or unsighted passengers, then the descent of the vehicle is controlled by c ither an operator at a remote control location, or by an operator at the landing place (who can be assumed to be receiving the goods or passengers). However, the system may also be used to transport freight, for example during a morning rush hour when the roads are busy.

As the landing place is directly below the vehicle, it is hard for a passenger inside said vehicle to get a good view of the state of the landing place below said vehicle. This is a particular problem if a pedestrian is approaching said landing place loom behind. It is lhet.Ctorc pretcrable to mount a video camera near lo said landing place, such as to provide a good view of said landing place, and the area around it. When said vehicle is ready to land. a video display inside said vehicle displays the view seen by said camera, allowing a passenger inside said vehicle lo safely direct the landing of said vehicle. The same video display can be used by an operator at a remote control location to control the landing of the vehicle.

A simpler syste n is use an appropriately placed mirror, located such as to allow passengers to see below their vehicle. Other alternatives include radar imaging and a transpare7nl vehicle floor. The video camera may be mounted on said vehicle itself rather than at a nearby site although this is less preferable. Some landing places may be fenced off. In such landing places, landing can remain under the control of a computer.

In embodiments of the invention the landing place is configured to alert pedestrians if a vehicle is likely to descend soon. This action is inspired by the behaviour of traffic lights and level crossings. If a vehicle is likely to descend to a landing place soon, the landing place may flash, vibrate, and make a distinctive sound. This warns pedestrians not to walk over the landing place.

Also described is a new solution for the problem of vehicle stability while landing.

Each landing place is placed such that it is adjacent to a vertical guide unit. Vehicles are configured to be able to grain onto said vertical guide unit in order to stabilise themselves on their descent.

Vertical guide units will typically be attached to the support posts that hold the guideway hi its elevated position. In some embodiments, the guide units may be hlegral with said posts.

These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which: Figure I is a front elevation view of the system, with a vehicle in the process of descending onto a landing place; Figure 2 is a plan view of the system; Figure 3 is a front elevation view showing a vehicle in its topmost position; Figure 4 is a Iront elevation view showing a vehicle having landed on a landing place; l igure 5a is a plan view of a possible grabber mechanism, with the grabber engaged; Figure 5b is a plait view of a possible grabber mechanism, with the grabber half way between it's engaged and retracted positions; Figure 5c is a plan view of a possible grabber mechanism, with the grabber retracted; Figure 6 is a more detailed view of the aforementioned grabber, showing how it mates with the vertical guide; Figure 7 is a side elevation view of the interior of a vehicle; Figure 8 is a cross-section through the guideway and bogie; Figure 9 is a side elevation view through the guideway and bogie; Figure 10 is a block diagram of a winch control system; Figure I I is a block diagram of a video imaging system; Figure 12 is a plan view ot a small guideway network including a waiting area; Figure 13 is a view of a taTTding place, illustrating warning mechanisms; and Figure 14 is a block diagram of a vehicle guidance system.

Figure I illustrates a typical implementation of a personal transportation system. A vehicle 4 is suspended loom a motive unit 2, which is in turn attached to an elevated guideway I. 'I'he guideway is supported in its elevated position by a support pole 8. In addition to supporting the guideway, the support pole also has a vertical guide 6.

When the vehicle 4 wishes to descend to a landing place 7, said vehicle stops above said landing place, and uses grabber units 13 to grip the vertical guide 6. thus stabilising said vehicle while said vehicle descends to the ground.

While flee vehicle 4 is moving along the guideway 1, said vehicle is strongly attached to its motive unit A. I lowever. when said vehicle is ready to land, said motive unit releases said vehicle. and lowers said vehicle down to the ground. In the embodiment illustrated, this is achieved by winching said vehicle down on the end of a cable 3. Said cable provides only the force needed to control the vertical position of said vehicle. Vehicle stability is governed entirely by the connection to the vertical guide 6. In some embodiments, said vehicle and said motive unit may be connected by more than one winch cable 3 thus affording increased safety and stability.

A vicieo camera 9 is attached to a site near to the landing place 7. Said video camera is configured to have a good view of the vehicle 4, said landing place, and the area surrounding them. The view obtained by said camera is displayed to a human operator so that they may see when it is safe for said vehicle to descend, and control the safe descent of said vehicle. In the design illustrated, said camera is mounted on the guideway structure 1.

In the design illustrated, the support pole 8 supports a horizontal support unit 12, and said support unit supports two guideway paths 51 and 10. The siding guideway path 51 is used by vehicles wishing to descend to the landing place 7. The bypass guideway path I () is used by vehicles wishing to pass by said landing place. In this way, vehicles waiting to descend do not obstruct the passage of vehicles wishing to go past.

In order to reduce street clutter, the guideway support system may also support other items such as street lamps 11. In some cases, the guideway support 8 structure or the vertical guide 6 may be integrated with the structure of a building.

A control panel 39 is provided to allow a human operator al a landing place 7 to control the descent ol a vehicle 4 onto said landing place. This will commonly be used if said human operator is receiving said vehicle.

If a human operator wishes to make a trip using the described transport system, said human operator will request an empty vehicle using the landing place controls 39.

When an empty vehicle arrives, said human operator will use said landing place controls to control the sate descent of said empty vehicle. When said empty vehicle has landed. said human operator will board said vehicle. Said human may inform the system of his or her chosen destination using said landing place controls or alternatively, by using controls inside said vehicle.

Once the human operator has closed the door of said vehicle, said vehicle may move raise itself to its elevated position automatically, without needing human direction. This may be done simultaneously with said human operator informing the system of his or her chosen desthation. Once the system has been informed of said chosen destination, and said vehicle is fully engaged with its motive unit 2 and disengaged from its vertical guide 6, said vehicle may proceed to said chosen destination along the elevated guideway 1.

If a human is waiting for the arrival of goods, then said human may use the landing place controls 39 lo request that the vehicle containing said goods proceed from a waiting bay to the landing place 7 al which said landing place controls are sited. When saicl vehicle arrives, said human operator will use said landing place controls to control the descent of said vehicle.

Just as a human operator can receive goods through the transport system, they can also send goods to other users. Goods may be placed in a vehicle 4 and said vehicle instructed to take said goods to a particular location for receipt by a particular user. One example where this is useful is in the return of trolleys to supermarkets. If a user has been shopping at a supermarket, they can push their trolley into a vehicle and take said trolley back home with them. Once said user has unloaded their shopping and finished with said trolley, said user places said trolley inside a vehicle and instructs said vehicle to return said trolley to said supermarket.

Some cmbodUnents nosy allow a sending user to send goods to a receiving user only if said receiving user has explicitly requested that said sending user be allowed to send goods to said receiving user- at the specified location. This reduces the likelihood of goods being left uncollected.

(;uideway strength, vehicle strength, and desired stopping distances impose a limit on the weight of a payload that can be safely carried by a given vehicle 4. Some embodiments may allow said vehicle to weigh its payload in order to check that it weighs less than a safe weight limit. 'I'his weighing process may be performed while said vehicle is being raised up into its elevated position, by measuring the amount of work that the motor has to do in order to lift the vehicle.

Figure 2 shows a plan view of' the same system illustrated in figure 1. A vehicle 4 is preparhg to land on a landing place 7, while parked in a siding path 51 which is part of a larger guideway network I. A junction 14 allows vehicles travelling along the guideway I to chose whether to travel into said siding, or to continue along the bypass path 10. In the figure, several other vehicles 15 are shown travailing along said guideway, unimpeded by the presence of a parked vehicle in said siding. A video can1era 9 is placed such as to give a view of said vehicle and said landing place. A street lamp l l is attached to the guideway structure. The whole assembly is supported with the aid by a support pole 8. A landing place control unit 39 is located near to said landing place.

Figure shows a from elevation view of the system in which a vehicle 4 has just slopped above a landhg place 7. Said vehicle has not yet engaged its grabber artns, and is still l'ully attached lo its motive unit 2.

[figure 4 shows a front elevation view of the system in which a vehicle 4 has landed on a landing place 7. The grabber anus 13 are still fully engaged with the vertical guide 6.

In some embodiments, it may be preferred for a vehicle 4 to stop some distance above the ground 5 rather than actually landing on it. This may be suitable if said vehicle is configurecl to have a passenger seat at the level of its floor. Such a design may be t'avoured t'or aerodynamic reasons as it can allow the height of said vehicle to be reduced. It is easier for a passenger to board such a vehicle if said vehicle is raised above the ground such as to cause said seat to be at a nonmal height for a seat.

Figure 5/\ shows a plan view ol'a possible implementation ova vertical stabilization g rabber system. with the grabber an11s fully engaged. Cirabber arms 13 hinge around a vertical axis 16 within the vehicle 4 such as to engage with a vertical guide 6. Said vertical guide is attached to the support pole 8.

Figurc 5B shows the same system as figure SA, but with the grabber arms 13 part way between being engaged and being retracted.

Figure 5(' shows the same syslerm as figure 5A, but with the grabber arms 13 fully retracted. With said grabber arms in this position, the vehicle is able to move freely along the guideway.

Figure 6 shows a more detailed view of the means by which the go abber engages with the vertical guide 6 in the system illustrated in figures 5A, 5B and 5C. The grabber arms 52 have roller- surfaces 17 that allow said arms to slide smoothly along said vertical guide. Said vertical guide is shaped such that a said grabber arm can swing in from the side without being obstructed by any corners. Said guide is attached to the main support pole 8.

The whole grabber system is designed such that, if the vehicle is slightly misaligned, a grabber should still be able to engage successfully and will pull the vehicle either f-'r-war-ds or backwards as appropriate.

Figure 7 shows a view of a possible interior for a vehicle 4. A video display 21 is placed such as to he easily visible to a passenger. In the embodiment illustrated, said video display is placed next to the front window 18 and above the leg space 20. When said vehicle is situated above a landing place and is ready to land, said video display shows the view as seen by a video camera. Said video camera is located such as to provide a good view of said vehicle and the landing place below it. A passenger can then use a set of controls 22 to manage the safe descent of said vehicle to the ground, guided by what they see in said video display. Persons skilled in the art will be aware of many forms that said set of controls might take - including a joystick, a set of buttons or a wheel.

Said controls are located such as to be easily reached by a passenger sitting in a seat 19.

When the vehicle 4is moving along the elevated guideway, the video display 21 can be used to display information about the journey, or to provide entertainment. For safety reasons, it is expected that, if controls are provided for such entertainment facilities, they be distinct from those used to control the descent of said vehicle.

Figure 8 show a cross-section through a guideway section and through a motive unit.

The motive unit is divided into a main bogie unit 45 and a vehicle attachment unit 46.

Said main bogie unit 45 rides within a guideway 1. In the embodiment illustrated, the guideway is an enclosed box section with a slot 44 in the bottom. A vertical linkage 29 extends through said slot and connects said main bogie unit to a suspended vehicle attachment unit 46.

A set of wheels 27 run upon traction surfaces 28 within the guideway 1. A set of side wheels 26 are mounted on vertical axes and configured to run along the interior side walls of the guideway. Said side wheels are thus configured to prevent said main wheels 27 IrOm coming into contact with the interior side walls of said guideway.

An electricity supply is carried on power rails 31 which run within said guideway. If the main guideway structure is constructed from an electrically conducting material, then an insulating layer 23 may be employed to separate said power rails from the main guideway structure. An electrical pickup 30 within the bogie brushes against said power rails allowing an electrical circuit to be formed through the main drive motor. In the embodiment illustrated, said power rails are mounted on the upper interior surface of the guicleway, however- persons skilled in the art will realize that there are many other places such power rails could be located. If the wheels 27 are made of a conducting naterial, then the traction surfaces 28 may also serve as power rails.

The guideway also contains data network rails 24. Electrical signals are sent along said network rails allowing vehicles to communicate with each other and with an external switchhg computer. Network pickup units 25 allow the bogie to connect to this network. Vehicles and external switching computers use this network to negotiate future paths for vehicles such that said vehicles do not collide. Error correction techniques may be used on said data network to compensate for the inherently noisy behaviour of a inrush connection. In other embodiments, the network may not be electrical; For example it may he a wireless radio network, or a light-based communication system.

Figurc 9 shows a side view ot the same guideway section and bogie unit as shown in Figure 8.

An electric motor 32 receives power from the power rails 31. Said motor may be switched between a first state in which said motor drives the rear wheels of the vehicle, and a second state in which said motor drives a winch 34. In other embodiments, separate motors may be used to perform these two tasks.

A winch 34 winds a cable 3 which is connected to the vehicle 4. By winding said winch cable said the winch, said vehicle may be raised and lowered. For safety reasons, this can only be done when said vehicle is engaged with a vertical guide as illustrated in figures 1, 3, 4. SA, 5B' and 5t'.

The winch cable 3 runs through a cable guide 33 to ensure that it is accurately positioned, and to allow the winch 34 to be offset from the centre of the bogie. Placing said winch away from the centre of the bogie may allow for a more convenient bogie layout, allowing more space for other items such as the motor 32.

When the vehicle 4 is lifted to its topmost position, locking units 36 fix said vehicle to the suspended vehicle attachment unit 45. Only when said locking units are fully engaged may said vehicle disengage from the vertical guide. Only when said vehicle is completely disengaged Irom said vertical guide may the motive bogie unit proceed to move along the guideway.

A compuicrised control unit 3.S connects to the data rails 24 via a data pickup 25. Said control unit controls the motor 32 and thus also the winch 34 and the wheels 27.

The control unit 35 communicates with the vehicle 4 through a data cable 47. Said data cable is wound onto a data cable tensioner 48, allowing said data cable to extend and refract as the distance of said vehicle from the bogie varies. An alternative design is to use the winch cable 3 to carry data, avoiding the need for a second cable.

Figure I () shows the different elements that communicate in order to control the winch.

The wincl1 m.iy be controlled by a human operator in the vehicle by using the passenger controls 22. Alternatively. the winch may be controlled by a human operator at the landhg place, using the landing place controls 39. As a third alternative, the winch may he controlled by a human operator al a remote location 4().

The winch controller 35 can communicate directly with the passenger controls 22 as there is a data cable 47 linking the bogie with the vehicle.

In order to communicate with the landing place controls 39, the vehicle must communicate over the local data network 37. Said network is carried along data rails within the local guideway section, and is connected to directly by the vehicle bogie and said landing place controls.

In order to communicate with remote controllers 40 the vehicle must communicate over a wide area network 38. In the preferred embodiment, said wide area network takes the form of a high bandwidth switched dale network over a dedicated network medium. The guideway local network 37 is connected to said wide area network such that any traffic on said wide area network that is relevant to said local network is repeated on saidlocal network. This local/wide area division is common in computer networks.

Figure I I shows the different elements that communicate in order for the signal from a video camera 9 to be made available to a human operator. Said human operator uses the view Cons said video camera to allow said human to safely guide the descent of a vehicle into the area viewed by said video camera. This design is very similar to that used t'or the control of the winch.

The video camera 9 is connected directly to the local network 37 that is carried within the Incas part ol the guicleway along the data rails. A display 21 inside a vehicle preparing lo land locally may receive a signal from said video camera via said local network.

If a video signal from the video camera 9 is needed by a remote display 43 then it is transmitted along the wide area network 38.

T here is no need lor a display to be provided for an operator at the landing place as said operator is assumed lo be located such as to have a good view of the landing place.

Figure 12 shows a small part ot a guideway network, including a landing place 7 and a waithg bay So. Waithg vehicles 42 are waiting in said waiting bay.

Whets goods are placed into a vehicle 4, said vehicle is given a destination and a chosen recipient 41. 11 said recipient has not yet requested the arrival of said vehicle, then said vehicle wails at a waiting bay 50. Said waiting bay is configured such that vehicles 42 hi the waiting bay do not obstruct other vehicles 15 on the network. A vehicle will normally wait ha a waiting bay that is close to the final destination of said vehicle.

When said recipient is ready to receive said vehicle, said recipient will use the landing place controls 39 to request the arrival of said vehicle. Said vehicle will then proceed to the landing place at which said landing place controls are sited. When said vehicle arrives at said landing place, said recipient will guide the descent of said vehicle lo the ground.

Waiting hays for goods vehicles arc kept fairly small so as to avoid having to move a large number of vehicles it a vehicle hi the middle of the bay wishes to leave for its destination. Alternatively, more elaborate vehicle storage systems may be employed to allow a vehicle to wait in a wailing area without obstructing other vehicles in said waiting area. In some embodiments, the sidings above landing places may also function as waiting hays.

An empty vehicle which is currently unneeded may also wait in a waiting bay 50. The central system may arrange t'or said empty vehicle to wail near to landing places which said central system predicts is likely to request a vehicle soon. For example an empty vehicle might wait hT residential areas in the morning and near office buildings in the evening.

Figure 13 ShOWS a front elevation view of a landing place 7, and the various mechanisms that it uses to warn humans when a vehicle is preparing to descend.

A landing place 7 is embedded into the surrounding pavement 59. Lights 54 in the landing place and lights 53 in on the adjacent support post flash when a vehicle is prcpaT-ing lo descend. Speakers 58 emit an audible warning. Electro-magnetic rams 55 vibrate a vibration platform 56 such as to give a tactile warning to anyone standing on said platform. Said platform may also act is a sensor to detect when an object is placed on said landing place. If such an obstruction is detected, then the system may prevent said vehicle descending to said landing place. In some embodiments, said platform may also be configured to weigh said vehicle to determine if the payload of said vehicle is heavies- than a defined maximum safe weight.

Data and power cables 57 connect the various warning devices to the landing place control panel 39 and the guideway network. Said data cable is used to inform the landing place 7 when a vehicle is expected to descend so that said landing place can activate its warning devices.

Figure 14 Shows the different elements that communicate in order for a vehicle to be correctly guided when travelling along the guideway. A vehicle is considered to be co'-rectly guided if it avoids coming into physical contact with other said vehicles, and if it eventually reaches its destination.

I'he guideway is comprised of a plurality of sections. Each section is managed by a local supervising controller 64. Said local supervising controller communicates with the vehicles leavening inside said section using a local data network 37.

Each vehicle has a positioning system 63 that discerns the position of said vehicle within the guideway section that it is currently travelling in. Such a positioning system can be constructed in many ways. For example it may respond to electromagnetic markers inside the guideway, or it may read an optical strip printed along a guideway wall.

A guidance controller 6() within a said vehicle is responsible for controlling the speed of said vehicle anti controlling the steering of said vehicle through junctions. The speed of said vehicle may be varied by use of a drive motor 37 and a braking unit 61, both of which are controlled by said guidance controller. The steering of said vehicle through guideway junctions is managed by a steering unit, which is also controlled by said guidance controller.

The guidance controller 60 communicates with the local supervising controller 64 via the guideway local network 37. Said guidance controller informs said supervising controller- of the position of the vehicle containing said guidance controller, and of the path that said vehicle wishes to take through the next junction. In return, said supervising controller informs said guidance controller of the speed that said vehicle should travel at in order to avoid coming into contact with other vehicles.

All other vehicles 15 on a guideway section also communicate with the local super-vising controller 64. Said local supervising controller is thus able to control the paths oi all vehicles within the guideway section that it manages.

A guideway section will typically be connected to other guideway sections. The local supervising controller 64 for a section will communicate with the adjacent supervising controllers 65 that control the adjacent guideway sections. Said local supervising controllers negotiate the flow of vehicles between their sections such as to ensure that no supervising controller allows a vehicle to move from a source section to a destination section unless the supervising controller for said destination section has agreed to accept said vehicle. l

There are many ways in which steering, switching, and computer control of vehicles may be accomplished. There is much prior art for techniques for the steering and switching of guideway-mounted vehicles, much of which is applicable for use in embodiments. Examples of such steering, switching and control systems have been cited earlier in this document.

The invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art within the scope of the claims appended hereto.

Claims

CLAIMS: 1 An overhead transportation system comprising: an elevated

guideway. comprising a network of paths connected by a plurality of jctior, p,iltS; a plurality of vehicles suspended below said guideway; means for a said vehicle lo move between a first position in which said vehicle is raised above the ground and can travel along said guideway and a second, descended position, in which said vehicle may be loaded and unloaded; a computer controller to control the motion of a said vehicle when said vehicle is in said first position such that said vehicle does not come into contact with other said vehicles while travelling along said guideway; and means lor a human operator to control the transition between said first and second positions
2. A transportation system in accordance with claim I wherein a said vehicle descends onto one of a plurality of designated landing places
3 A transportation system in accordance with claim 2 wherein a said landing place is configured to be visually distinctive, to warn people that vehicles are able to descend to the ground at said location.
4. A transportation system in accordance with claim 2 or claim 3 wherein a said landing place is configured to change its visual appearance to warn of an irmninent descent, if it is expected that one of said vehicles will descend onto said landing place soon.
5. A transportation system in accordance with claim 4 wher-eh this change of visual appearance takes the form of said landing place emitting light of a flashing nature.
6. A transportation system in accordance with claim wherein a said landing place is configured to produce an audible signal if it is expected that one of said vehicles will descend onto said landing place soon.
7. A transportation system in accordance with claim 2 wherein a said landing place is configured to produce a vibrating signal if it is expected that one of said vehicles will descend onto said landing place soon.
S. A transportation system in accordance with claim 1 wherein means is provided for the payload of a said vehicle to be weighed, so as lo deterrnirie whether the weight of said payload is below some safe limit.
9. A transportation system in accordance with claim 2 wherein a said guideway is configured to have normal paths, and siding paths, such that in normal use vehicles stop only on said siding paths.
10. A transportation system in accordance with claim 9 wherein a said landing place is located underneath a said siding path.
11. A transportation system in accordance with any proceeding claim, further comprising: a plurality of vertical guide units.
12. A transportation system in accordance with claim I I wherein, a said vehicle is configured to attach itself to a said vertical guide unit when moving between said first and second positions.
13. A transportation system in accordance with claim 12 wherein a said guideway is supported in its elevated position by a plurality of guitleway support units, each having an upper end at'fixed to said guideway, and a lower end al'l'ixed to the ground.
14. A transportation system in accordance with claim 13 wherein a said vertical guide unit is affixed to a said guideway support unit.
15. A transportation system in accordance with claim 12 wherein a said vehicle is configured to attach itself to a said vertical guide unit by means of an arm; said arm having a first position in which said and is retracted away from said vertical guide unit; and a second position, in which said arm is engaged with said vertical guide unit.
16. A transportation system in accordance with any proceeding claim wherein the transition of a said vehicle between said first and second positions is controllable by a passenger inside said vehicle.
17. A transportation system in accordance with claim 16 wherein means is provided for a passenger inside of a said vehicle to view a visual representation oi said vehicle and of the area that said vehicle is to descend into.
18. A transportation system in accordance with claim 17 wherein an imaging system is located such as to provide a view of said landing place, and ol any vehicle preparing to land on said landing place.
19. A transportation system in accordance with claim 18 wherein the view seen by a said imaging system is communicated to a vehicle preparing to land at the landing place viewed by said imaging system, such that said view is viewabic by a passenger intending to control the descent of said vehicle.
2(). A transportation system in accordance with any proceeding claim wherein the transition of a said vehicle between said first and second positions is controllable by a human operator located at a remote location.
21. A transportation system in accordance with any proceeding cla wherein the transition of a said vehicle between said first and second positions is controllable by a human operator at the landing place at which said vehicle is preparing lo land.
22. A transportation system in accordance with claim 21 further comprising a plurality of waiting areas at which vehicles may wait before proceeding to a landhig place.

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23. A transportation system in accordance with claim 22 wherein a said vehicle is configured to consider a particular landing place to be its destination and a particular human operator to be its recipient.
24. A transportation system in accordance with claim 23 wherein a said vehicle is configured to proceed to said destination landing place only when said recipient has requested the arrival of said vehicle.
25. A transportation system in accordance with claim 24 wherein a said vehicle may wait in a said waiting area while waiting for said recipient to make said request.
26. A transportation system in accordance with claim I wherein said second position, while being less elevated than said first position, is still elevated above the ground.
27. A vehicle for the transportation system of any proceeding claim.
28. A guideway system for the transportation system in accordance of any one of claims I to 26.