General topics about the Carsystem
When back in the year 2000 the idea of the Miniatur Wunderland was born, the desire to extensively develop the then already known Faller-Car-System plus a computerized control system, was vital. First thought of as a supplement to the train layout, it turned out to be a whole project of it’s own, consuming 2500 hours until the inauguration of the layout. From August, 2001 until today (2007), the further development used up at least another 3500 hours. The vehicle building (heavily under-estimated in the beginng) needed another 2000 working hours. We didn’t want the controlling software to work down fixed step chains but rather supplying a kind of “brain” for each vehicle. Right now, this system is limited to 65000 vehicles. As far as computing power goes, only 1000 vehicles are realistic for the Wunderland layout. The basic data for the streets comprise of roughly 12000 parameters for Knuffingen and about 14000 parameters in the USA section. Examples are: streets (with exact dimensions down to the millimetre), gradients, curve radii, right of way, traffic lights (complex, endless signal lights control with turning cars, “Green stretches”, Day-/Night mode, etc…), grade crossings, turnouts, occupancy detection, radar traps, speed measuring, vehicle type permissions,………..
Currently, the program has one process for each car which calculates all situations for this vehicle 20 times per second. A vehicle can either just ride the streets, have a fixed tour (like buses or trash trucks), have a fixed destination, or be on it’s way to an incident (fire fighters, oversize load transport). For each vehicle the exact location has to be determined, as well as the next decision-point for this very vehicle. Such a decision could be : “tailing” another car, approaching a crossing (with or without right of way), entering the highway (relatively complicated because eventually another car has to be told to change lanes if not yet noticed by the car already on the highway), a weak battery, etc. A vehicle (resp. the PC-program) decides at every turnout which way to go and considers a couple of criteria. In general, there is the chance that a car has no destination, i.e., it is “cruising the streets” on a random base. Other possibilities are that a fixed destination has to be reached, a certain route has been defined, or a defined step chain has to be “worked down” (like fire incidents or the trash trucks). At a turnout or crossing, the vehicle first checks if the new route is permitted for this type of car, if the route eventually points to the vehicle’s destination (imagine virtual “roadsigns” at every crossing), if the route is free (resp., free in a way that the vehicle doesn’t need to stop if the route was selected), if the route is not currently blocked by a fire fighter scenario (should this be the case, the vehicle checks other routes and also, if the detour is permitted for it’s type of vehicle). Should more than one route fulfil all criteria, the vehicle randomly selects a route whereby different probabilities are defined (so that a truck seldom enters dwelling areas). Once the vehicle selected a route, it checks if an indicator light is need or if it has to stop (if a car has to stop on the highway, hazard lights come on automatically). If there are no obstructions on the newly selected route, it is entered and driven on with the speed defined for this route.
In any case, the vehicles check their right of way, stick to the “drive at right”-rule on the highway, stop at closed crossing gates, obey traffic lights, grant the right of way to fire engines with horn and lights on, and stop at pedestrian crossings. If stuck in a jam, they also let a car from a side street sneak in, and they also wait patiently behind trash trucks with frequent stops. There are also rowdies that race the street, get caught in a radar trap and shortly after that have to make an involuntary stop at the policeman’s stop sign (hopefully, the computerized policeman will not fall short to the time pressure). Buses make scheduled stops and at night all vehicles switch on their headlights. At dawn, the headlights are switched off again; except for Scandinavia. In the German section, about 10% of the cars run with headlights on during daylight – this is randomly controlled (Note: we simulate a day – night cycle within 15 minutes using computer-controlled dimmable fluorescents mounted to the ceiling and behind the layout).
Apart from the daily individual traffic, we put a strong emphasis on programmed scenarios – most of them are some sort of fires but you might also see a truck hauling an oversized load, escorted by police.
The Knuffingen section is currently equipped with 11 different scenarios (the USA-section has 9, and Scandinavia 2 small ones). If a visitor pushes a button on the railing of the layout labelled „Fire incident“, the program randomly selects a scenario (Note: Currently, the scenarios are selected and started at the control stand). After that, for example, smoke starts billowing from a house and first flames become visible. The alarm in the fire station is sounding, the lights go on, and shortly after that the fire brigade (3 – 4 vehicles) switch on headlights, top lights, and front strobes. At the same time, all traffic on the main road stops in front of the sign “Attention – Fire Fighters”. The fire brigade starts moving to the incident area where in the meantime the fire grew larger. At street crossings the horn is heard and the fire engines have their right of way. After the fire engines arrived at the incident area, the PC decides wether the fire had successfully been put out or if the fire develops into a blaze. Should the latter be the case, another alarm is initiated and more fire engines (up to 35) from the neighborhood have to come to help.