Republic Vehicles
Travel Without Limits.
Jumlah Pengunjung
Rabu, 16 Februari 2011
Fleetwood storm 32BH
Guidance System
About The Guidance System.Initially the optical 'self-steering' guidance system was called 'Visée', but when Matra (who developed it) was bought out by Siemens they rebranded the technology as 'Optiguide'.When first introduced 'Visée' was claimed to be the first technology to use Artificial Vision in passenger transport. It works by a forward looking video camera detecting the correct path by 'seeing' the contrast between a 'virtual rail' comprising of twin white dashed lines and the darker road surface on which they are painted (typically normal white traffic paint is used), with the image being analysed by a computer to determine the vehicle's position relative to its expected path and then adjusting the steering as required. There are two options for the virtual rail, with this being located either down the centre of the vehicle or offset to the left. Originally developed to enable accurate docking at bus stops, experience found that it could be equally competent for full-time vehicle guidance, albeit at speeds of up to 40 km/h (about 25mph). When used solely for bus stop docking the 'virtual rail' usually extends 50 metres in each direction before and after the bus stop. The design criteria is for a horizontal gap of 6cm (a little under 2½") between the bus and bus stop platform. Although perhaps intended for 'rubber tyred' tram-like vehicles Optical guidance can be fitted to other types of bus as well - initially most trials used otherwise 'standard' Renault (Irisbus) Agora diesel buses and nowadays some of the other bus designs within the Irisbus family use it too (see below). On the Irisbus stand at the 1999 UITP exhibition in Toronto a short promotional film showed a Renault (Irisbus) Agora bus fitted with optical guidance undergoing trials. Scenes included safe operation in a wide variety of climatic conditions including torrential rain and fog (but not snow), and how easily the driver can safely regain steering control to take emergency action to avoid a potential collision / accident. Interestingly, the film also showed a Civis prototype equipped with O-Bahn / kerb guided bus style guide-wheels while a computer simulation demonstrated it on a mixed mode journey combining both guidance systems. The presence of the raised kerbs would be to help meet safety concerns regarding situations where (for instance) the guidance lines become invisible to the camera - such as in wintry weather conditions - and on slippery roads when safety dictates that all rubber-tyred traffic have to slow down. Originally the raised kerbs and physical guidewheels were stated to only be needed in case the optical guidance system derailed (with there not being any physical contact at other times) but at least one system promoter has suggested using the physical system instead (although many years later this has not come to pass). | ||
| Irisbus promotional photograph showing a flat (conventional bus) fronted Cristalis bus on the TEOR route in Rouen. | Scan from Irisbus promotional leaflet showing "hands free" driving. | |
| Agora L on Rouen TEOR line T1 at the "Mont aux Malades" terminus at Mont-Saint-Aignan. Agora buses locate their camera systems at the base of the windscreen just inside the bus. http://commons.wikimedia.org/wiki/File:10-01-08_228_T1_6.JPG. | Citelis 18 on Rouen TEOR line at the "Bizet" terminus at Canteleu. Citelis buses locate their camera systems in a visually distinctive way in a roof mounted pod at the front of the bus. http://commons.wikimedia.org/wiki/File:28-07-08_6108_T3.JPG. | |
Optical guidance light urban transport
Civis, Cristalis and Optical Guidance.Intended for medium sized towns and the suburbs of larger cities the Civis concept was originally for a complete transport package including vehicles, guidance system and street furniture. When launched it was marketed as a Reserved Lane Light Urban Transport System and designed to be suitable for traffic flows of up to 3,000 passengers per hour / per direction.Civis was developed by Renault and Matra, two well established French transport concerns. Since then Matra was bought out by Siemens and Renault's bus and coach division merged with the Fiat-Iveco group's bus and coach division. However the euro-bureaucrats cried foul claiming that the latter merger was anti-competitive (as if there are no other bus builders anywhere globally!!!) and demanded a change in ownership, so since early 2003 Irisbus has been fully owned by the Iveco Group. The traction equipment is sourced from Alsthom. (It is to be regretted that there is no-one with similar powers to cry foul over the euro-bureaucrats not being elected to office, not being democratically accountable, or that because oodles of [British & European] [our] taxpayers' money goes astray within the EU 2007 marked the 14th consecutive year since auditors were last willing to approve its accounts). | ||
| A 'rigid' (not articulated) Cristalis in Limoges, France. http://commons.wikimedia.org/wiki/ File:Trolleybus_Cristalis_ligne_4.JPG | Irisbus promotional image of an articulated Bologna, Italy, Trolleybus Rapid Transit (TBRT) Civis. | |
About The Vehicles.The vehicles come in two variants which share essentially the same bodywork and drive systems. The Civis is aimed at the "rubber-tyred tram / streetcar" market and the vehicles feature a pointed front where the driver sits centrally in a railway-style cab. This adds a little to the overall length and is only suitable for 'off-vehicle' fare collection systems which do not need to be supervised by the driver. Orginally it was expected that vehicles which use this configuration would also always use the optical self-steering guidance system, although this is not how things eventually came to pass. The other basic body variant features a more conventional bus-style flat front making these vehicles more akin to state-of-the-art 'second generation' modern buses. These are generally known as Cristalis.For length there are several options: 12 metre rigid, 18.50 metre (Cristalis) / 18.75 metre (Civis) single-articulated and 24 metre double-articulated (Civis only - in the original design specifications but not known to have ever actually been built). All variants are 2.55 metres wide, this being the euro-standard maximum width for buses. Production is mostly based at Rorthais in the centre-west of France, near to Nantes, although the chassis is treated with a full anti-corrosion immersion process (cataphoresis) at the main Irisbus bus plant at Annonay. The structure is fabricated out of stainless steel; the main side framing is very substantial, partly because with an integral low floor architecture most ancillaries are located at roof level. Over the last two decades a production system has been developed whereby the two main sides, front & rear ends plus roof are all constructed as separate sub-assemblies. They are built complete with glazing, wiring and trim, then, late in the production process, bolted to the chassis and to each other, to make a very strong structure. One of the features carried over from the conventional bus range is the use of main side panels made in a fibreglass material which are both visually attractive and easier to repair in the event of minor bumps and scrapes. The vehicles are electrically operated, either as trolleybuses which collect 750v dc power from twin overhead wires via poles mounted on the vehicle's roof, or as diesel-electric hybrid style buses where a rear mounted 224kW / 300 HP Iveco Euro 3 fossil engine powers an electric generator (alternator). Note that unlike other types of hybrid bus propulsion systems the diesel-electric variant does not include energy regeneration or storage, and although well proven on the railways it has proven to be something of an Achilees Heel when used on buses. The trolleybus variants can also fitted with a low power 66kW / 88 HP diesel alternator APU (auxiliary power unit) which gives them an ability to travel off-wire at reduced speed - many trolleybuses feature an APU as it is useful for emergency (and depôt) use allowing the vehicle to travel away from the power supply around an obstruction (eg: a road traffic accident). Transmission is via 80kw electric wheelhub motors driving the centre (articulated variants only) and rear wheels which feature the extra-wide low profile Michelin 'Super-Single' tyres obviating the need for paired wheels. These state-of-the-art tyres are designed to limit ground floor pressure, save 130kg per axle in weight, reduce rolling resistance (and hence energy consumption) and enable the vehicles' interior to be as wide at the back as at the front. This saves about 40cm in internal width. The main entrance doors are electrically operated. The twinleaf doors open outward and sit very close to the side of the body. When using guidance systems the buses can dock so close to raised compatible kerbs that there is practically no gap. However, for non-guided vehicles there are the usual options of kneeling suspension and ramps. With accurate docking the bus stop platform can be raised up to 27 cm (or 21 cm when the vehicle is kneeled), to provide accessibility to every user. | ||
| Cristalis trolleybus in Milan, Italy, on a priority road which is restricted to public transport, bikers and the emergency services. The leaf motifs represent a type of tree which grows along many of the tree-lined avenues served by these trolleybuses on routes 90/91. The building in the background is the central railway station; the vehicles behind the bus are taxis which had to stop whilst the bus called at a bus stop. | Scan from Irisbus promotional leaflet showing the inside of a Cristalis; the skylights are a feature of both vehicle ranges. | |
| Rear view of a 'rigid' (not articulated) Cristalis in Lyon, France. The rear window is a very welcome feature which too often bus designers leave out. | Side three-quarter view of an 'articulated' Cristalis on the very busy route No.1 in Lyon, France | |
Transport in Bogota
| | |||||||||||||
| |
|
Selasa, 15 Februari 2011
Scania OmniLink
This great connector knows no 'city limits'. When you need to bridge downtown routes with the suburbs and beyond, Scania OmniLink does the job with style.
The flat and obstruction-free floor extends beyond the middle doors, allowing passengers to move easily at the front of the bus and sit comfortably with good visibility in the rear. The flexible floor layout makes it possible to accommodate many forward-facing seats while including seating for the elderly and infirm.
A low floor and full side kneeling promotes smooth passenger entry and exit. Safety and reliability have been further enhanced by incorporating the kneeling function in the intelligent electrical system.
The longitudinally installed engine meets your choice of Euro 4 and EEV requirements for emissions compliance, and all daily inspection points are conveniently gathered together for easy access.
Available in 12- to 15-metre versions (the longer with steered tag axle) and as 18-metre articulated, all with the same excellent manoeuvring and handling characteristics.
Comparison with other forms of mass transit
BRT systems come in a variety of forms, such as dedicated busways with their own rights-of-way (e.g., the Ottawa Transitway or the Pittsburgh MLK East Busway), bus services usingHOV lanes, dedicated freeway lanes (e.g., Honolulu's CityExpress) and limited-stop buses on pre-existing routes.
TransMilenio BRT system in Bogotá, Colombia, holds a record 40,000 passengers per hour.
BRT attempts to combine the advantages of a metro system (noticeably right-of-way, which improves punctuality and frequency) with the advantages of a bus system (low construction and maintenance costs, low vehicle costs, right-of-way not required for entire length, and for the ability of feeder bus services to join a trunk busway).
TransMilenio BRT system in Bogotá, Colombia, holds a record 40,000 passengers per hour.
BRT attempts to combine the advantages of a metro system (noticeably right-of-way, which improves punctuality and frequency) with the advantages of a bus system (low construction and maintenance costs, low vehicle costs, right-of-way not required for entire length, and for the ability of feeder bus services to join a trunk busway).
Langganan:
Komentar (Atom)