Dynamic brake force counted twice

[malatzoc]

Do anyone noticed that the dynamic brakes are too powerful in the game (not with TS2014 update, it was like this since years)? Of course a lot of people did, but very few noticed why is that: the game counts the dynamic brake force TWICE. So the value set in configuration files are correct, the game's physics engine isn't.
An example: You set 160kN in DynamicBrakeEffortVsSpeed.csv or dcsv files, then the game will write 160kN too(Acceleration (the name is wrong, this control value feeds back the forces and not the actual acceleration)) when you are using the dynamic brakes, but it doesn't feels right. It's easy to find out what's going on, just use a little bit of maths, F=ma where F is force, m is mass a is acceleration.
The mass set for a locomotive, can be found out by opening the engine blueprint and finding the line "Mass" (in this example it's 84000kg), and the acceleration can be found out(if you don't want to script) by using -EnableSoundDebugDialogs start parameter for TS2014, then open the proxies(beware the game usually placing the dialog behing the start menu), select your locomotive's bogie sound control, and watch the Acceleration value.
When 160kN is set for the example locomotive you will see acceleration at max dynamic brake force around -3,8 m/s2, which is waaay too much. Now using the formula, m=84000kg, a=-3,8m/s2, using F=ma is around 320000N= 320kN, which is twice as much as it should be.
My tip is, the chaotic mixed standard system of the game made some programmer confused. While the code that computes the pulling force interprets the mass and the force correctly (as kg and kN), the dynamic brake code interprets the mass as lbs, which explains the problem written above.

[jstange]

Hi,

I think this is nothing new. This is why the HRQ Taurus developer changed the breakforce to half of the real value several months ago...

But you may be right with the units to be the source of the problem (lbs vs. kg). Even NASA probes in outer space failed once or twice because of such a confusion so why not TS?

[RichyV]

Hi,

I think this is nothing new. This is why the HRQ Taurus developer changed the breakforce to half of the real value several months ago...

But you may be right with the units to be the source of the problem (lbs vs. kg). Even NASA probes in outer space failed once or twice because of such a confusion so why not TS?

...and, sadly, why some aircraft ran out of fuel...

[MaikG]

....An example: You set 160kN in DynamicBrakeEffortVsSpeed.csv or dcsv files, then the game will write 160kN ....

Here is your first error. You don't have to set kN in the DBvsS.csv but percent / 100. Try it, it works perfectly.

[malatzoc]

....An example: You set 160kN in DynamicBrakeEffortVsSpeed.csv or dcsv files, then the game will write 160kN ....

Here is your first error. You don't have to set kN in the DBvsS.csv but percent / 100. Try it, it works perfectly.

Oh i forgot, yes it's set as percentages in the csv but the result is the same the the feedback of the force values are half(160kN on accelerometer control value) of the real noticeable force in game(320kN), and works like written above, which is not perfect at all.

[MaikG]

Your'e using a value for your math comparings that is not really useful, the accleration for the audio engine. It wasn't right before and isn't right today. It shows to much acceleration that isn't there if you count the seconds to reach a specific speed on full throttle or the way to decellerate to a specific speed from a specific speed in a known timescale. I done a lot of electric brakes in our locos and anytimes it works like in the prototypical versions. Just don't use that audio value, use other maths to compare.

[malatzoc]

That value is just correct(i'm talking about the bogie's acceleration value, not the locomotive's "Accelerometer" control value which is the force in kN, and not acceleration, the name is wrong), just like what is written out by Call GetAcceleration, and the same can be computed from the SpeedometerKPH and time. (If the feeling is not enough to notice that a locomotive the speed change is the same with 100% throttle and 100% dynamic brake, while the dynamic brake is set to half of the traction force)...
All of the values(bogie's Acceleration value, GetAcceleration call in lua script) that are REALLY feed back the acceleration are correct, just fluctuating a bit, which can be solved by smoothing that with moving average.