Trying to understand Pit Stop/Refueling

[BigBadBuzz]

Ricky T.:

I know this subject has been discussed in previous forum posts, but I didn't get a clear understanding of how pit stops/car refueling work in UR 3.0 - so forgive this rehashing of the topic. First of all, my track is Tomy/AFX HO - I took several hours to look on the web to see if there was any kind of old track still available that I could make "real" pit stops with - I didn't find any. So, I started looking at the pit stop or refueling options that various race management software provides. I found one where you stopped your car for 2 seconds on the same detector used for counting laps; that seems cool, but probably hard to hit that small target. So, I eventually ended up reading about how UR 3.0 handles it - and there is where i got a bit confused.
I drew the diagrams below to try to depict how I THINK (or hope) it works - I'd appreciate it fi you'll tell me if I am right, or if not, correct my misunderstanding.
Pit Stop-Refueling.gif
The upper portion of the diagram shows a 2-lane track with two infrared detectors in each lane - the regular lap count detector (blue circles) and a second "pit out" infrared detector (green circles). If I understand how this might work, after the car passes by the lap count detector, it enters the "pit area" - i.e., the place between the two detectors. As long as the car doesn't go past the "pit out" detector, it is still in the pit, and would get refueled. That assumes that UR 3 (or whatever the input device is, like a Phidget digital input) ignores the times when there are very short times between detector outputs - i.e., during normal racing.
Since UR 3 only has one pit sensor signal per lane, you have to have somehow combine the signals from the lap count and "pit out" infrared detectors. I don't know if UR 3 would allow the signals to be combined and feed the SAME SIGNAL into both the "Detect Slot Car" and "Pit Sensor" inputs for a lane, so I drew a logic OR gate that combines the signals to feed only the lane's "Pit Sensor" input. The bottom portion of my drawing shows how the timing would look for such a hardware setup.
So would UR3 work with this setup? What does the "Wait (ms) before refuel starts" in Circuit Settings do? Any help would be most appreciated - it seems adding this feature to my track would result in a lot of fun and additional challenge!

Regards,
Paul (BBB)

[Pepsikid51]

BigBadBuzz,


Here’s an attempt to explain Pitting and Refueling in UR30. First off, they are 2 separate (but closely related items). Pit stop is the term used to describe the AREA where a Car is in the Pits and is hardware defined. Fueling / Refueling is something that can only take place when in the pit area and currently is the only software event associated within the pit area. We allow a car to be removed from the track for minor repairs (braid or tire adjustment) only from the pit area.

The Pit Stop: Hardware defined (Sensor) and configured on [Circuit settings] (Pit stop management). 2 options are possible, “Detect a pit IN and a pit OUT” (2 sensor setup) or “Detect a slot car inside the pit” (single sensor). A single sensor setup is possible because the sensor has 2 states (Low, High). The default state is low (no car detected), when a car is detected the state goes high and remains high until it no longer detects the car, then it changes to low. Thus as long as a car is being detected it is considered inside the pit area. Depending on the type sensor used this can be a very small area. I use a Light bridge which essentially provides a car length for the zone and works well. The other option IN and OUT does requires 2 detection sensors but allows a larger area to be designated.
1) Detect pit IN and pit OUT (2 dedicated sensors) – Yes, your thought of using 1 sensor for multiple uses (Timing & Pit) for one end is possible but do not believe configurable as such in UR30 (using same pin). My work around is I wire the sensor to 2 separate pins which now allows for 2 events from the same sensor. I have not had a problem and dual purpose all my light bridges. Not being some electronics type I’m not sure it is the best solution but does work.
2) Detect a slot car inside the pit (1 sensor) – Only 1 sensor required but area is limited to sensor’s detection. This is the way my primary circuit is configured and works flawless with the light bridge.

Fueling / Refueling: This is a software routine that requires parameters to be set on [Circuit settings] (Pit stop management) and the [Heat setting] (Fuel Management). Additionally [Slotcars] (Fuel management) has Car specific options available if you want to use them. Any Fuel function requires a proper Pit Area hardware (sensor(s)) configuration for use. Fueling is then controlled by the parameters set accordingly.
1) [Circuit Settings] (Pit stop Management) – Detection properties are for configuration of hardware and MUST be in place for any Fuel events to occur. “Add lap after pit stop” and “Wait (ms) before refuel starts” are global parameters for a circuit.
ADD a lap option - 1 lap is added (toward heat completion) to a driver when its slot car leaves the pit area or refueling is complete if checked. Care should be used when selecting this option and is best suited when pit lane avoids the Start/Finish line, if pit is part of normal circuit leave unchecked.
WAIT (ms) before refueling starts option - Time is in milliseconds (ms), this delay may be necessary especially when the Pit is a part of the regular circuit. This delay allows car to pass the sensor without refueling on every lap. Fueling will only start after a car is detected for the described time, note: it is not the time required for fueling, but allows the software to differentiate between just passing the pit or going into it.
2) [Heat settings] (Fuel Management) – Fuel management, Cut power, and Warning level options are set here.
FUEL Management – must be checked if you want to use fueling during heats regardless if circuit is configured, if not checked all Fueling parameters are ignored.
CUT POWER when out of fuel – This option will cut power to the lane when a car is out of fuel. A circuit MUST be configured for individual lane power control for this option to valid. If “Cut power” option is used the Car/Driver’s heat is terminated at that point. If power is not cut, lap counting is suspended (no laps will be counted toward heat completion) but car can proceed to pit area and refuel, then continue having been penalized time it took to get to pits and refuel.
FUEL WARNING level – This is the point at which the low fuel light starts to blink indicating fuel is getting low. By design the low fuel light blinks when low and is steady when out of fuel.
3) [Slotcars] (Fuel management) – Laps before refueling and Refuel speed, are Car specific
parameters with Reference average speed a software supplied value. A Slot car fuel consumption is proportional toits average lap duration (see “reference average speed” below). Thus the slot car fuel decreases each time a slot car completes a lap by a factor according to how fast/slow that lap was compared to its average. The faster it goes the more fuel it uses, but it always uses something.
LAPS before refueling – This value is your input for the average laps a slot car can run with a full tank at an average speed, it’s the baseline that will determine fuel consumption using the Reference average speed. Not all cars have same capacity tanks, this allows factor for that consideration.
REFUEL speed - This variable is your input for the minimum time it takes to simulate taking a FULL fuel load, if less time is used... less fuel is taken in.
The "reference average speed" is the slot cars average speed. This parameter is calculated by UR30 from the slot car lap statistics. The slot car consumption uses this parameter as a reference to compute fuel consumption.


More info is available through HELP, good luck.