Started by jamespetts, December 08, 2015, 12:31:28 AM
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Quote from: jamespetts on August 07, 2018, 12:07:09 PMthe difficulty is: (1) a single dynamic model (i.e., one in which fuel consumption changes with power output but fuel efficiency does not) is likely to lead to worse fidelity to real values than a static averaged system;
Quote from: ACarlotti on August 07, 2018, 04:37:01 PMI don't believe this can be true. If the dynamic model is used in the code, then it would still be possible to use the current static costs by setting all the dynamic (i.e. new) costs to zero. We are not throwing away the existing cost mechanisms, merely adding new ones that can be used in parallel.
QuoteIf there are any cases where a completely static model truly is better than the simple dynamic model, then we can continue effectively using that.
QuoteThis get-out might not work for trains, but I think trains are where the simple dynamic system will give the greatest improvements over the static system. Indeed, I don't think you have responded to my scenario in reply #34 (cost savings due to switching to a more efficient locomotive should be greater for longer/heavier train).
QuoteI think it is currently impossible to produce accurate (or close to accurate) running costs for all four combinations of:1. A diesel locomotive with high energy costs2. An electric locomotive with low energy costsand:a. A short train of (say) 2 coal wagonsb. A long train of (say) 20 coal wagonsClearly replacing 1b with 2b should lead to a greater reduction in running costs than replacing 1a with 2a, but at present these two replacements cannot produce different reductions in costs.So this suggests that some account of actual energy consumption is needed in the long run.
QuoteI think the best way forward is to modify the code to allow for dynamic running costs, and then try them out. If it does turn out to give worse operational costs, then we can revert to the current model without any further changes to the code (perhaps even leaving dynamic costs as an option for other paksets).
Quote from: jamespetts on December 26, 2019, 12:51:28 AMthus removing nearly all incentive from players to use all but the most powerful vehicles for every possible task
Quote from: Qayyum on December 26, 2019, 08:14:38 AMFor steam engines, would boiler pressure be a good measure to calculate how much force a locomotive with a set number of carriages can take, assuming the gradient is zero degrees?
Quote from: jamespetts on December 26, 2019, 12:50:29 PMThe simplest formula would be simply to take the current speed as a proportion of the maximum physical speed and apply that proportion to the fuel consumption so that, if a vehicle is not accelerating nor decelerating and travelling at 50% of its maximum physical speed, its fuel consumption would be 50% of what the stage 1 formula gives us.
Quote from: Qayyum on December 26, 2019, 03:36:12 PMOne complexity in all this is aircraft. Aircraft data generally show fuel burnt per hour and their maximum cruise speed, but their actual maximum speeds are almost never given and may not be obtainable without damaging the airframe and therefore destroying the aircraft.
Quote from: DrSuperGood on December 26, 2019, 05:37:45 PMI think at high speeds, traveling at half the speed uses much less than half the power due to how drag works.
QuoteOne could in theory calculate aircraft per tile cost at time of take off based on their weight and the distance to destination and maintain that for the rest of the flight.Of course this does not solve the problem of getting the data in the first place.
Quote from: jamespetts on December 26, 2019, 06:33:23 PMAre you able to suggest a workable algorithm to use here?
Quote from: jamespetts on December 26, 2019, 06:33:23 PMHow would calculating it in advance assist?
Quote from: Phystam on December 26, 2019, 06:44:13 AMFor resistance:According to physics, running resistance consists of 3 terms as follows:R= C + D*v + E*v^2,where C is rolling, D is viscous, E is inertial resistance.
Quote from: jamespetts on December 30, 2019, 11:04:25 AMGiven the discussions here, there may be some merit to allowing players to limit the speed of vehicles in the schedule, but this will need careful consideration.
Quote from: Vladki on December 30, 2019, 09:39:44 PMAbout the schedules. I think it would be enough to improve the current system with two changes- flag if the latest departure time slot was used or not (probably we already have this to show green/cyan colored lines that miss their slots?)- way to adjust the tolerable delay, and let trains depart if they are within tolerance, and the previous slot was not used.
Quote from: Spenk009 on January 01, 2020, 09:34:56 PMI had originally intended to reply in the thread here, but this is probably better suited to this thread.May I suggest limiting the power in the schedule? If given the option to limit the power in percentage of total convoy power or percentage of top speed [power reduced accordingly to reach the new top speed]). There is a relation to power efficiency that can be generalized and extrapolated accordingly. In combination with the quoted post by vladki, if a delay is registered the convoy allows for a set delayed max power or automatically uses 100% of its theoretical power.
Quote from: Spenk009 on January 01, 2020, 09:34:56 PMMay I suggest limiting the power in the schedule? If given the option to limit the power in percentage of total convoy power or percentage of top speed [power reduced accordingly to reach the new top speed]). There is a relation to power efficiency that can be generalized and extrapolated accordingly. In combination with the quoted post by vladki, if a delay is registered the convoy allows for a set delayed max power or automatically uses 100% of its theoretical power.
Quote from: Ranran on January 02, 2020, 12:31:49 AMAlso, setting a low speed limit for lines where the vehicle has a high top speed but never reaches the top speed of convoy due to the low speed of the track, thereby reducing fuel consumption, is probably a more realistic simulation.
Quote from: DrSuperGood on January 02, 2020, 01:05:19 AMThis should make no difference as once it is at top speed it stops burning power to accelerate and so becomes more economical anyway?
Quote from: jamespetts on August 26, 2020, 06:13:48 PMand I suspect that it will have been done for rail and road vehicles, too, but I am not sure.
Quote from: Ranran on August 26, 2020, 06:56:41 PMI think in order for this to work well, we first need to completely separate the labor cost from the runnning cost.
# Coal, per kg1=1750,150,1800,100,1850,70,1870,60,1890,60,1900,50,1920,70,1940,75,1950,80,2000,70# Petrol, per centilitre2=1890,25,1900,20,1920,25,1930,26,1940,50,1950,40,1960,42,1970,45,1973,90,1980,80,1990,85,2000,90,2008,95,205,85# Electricity, per kw3=1890,40,1900,35,1920,36,1930,30,1950,30,1960,32,1973,40,1980,40,1990,45,2000,50,2020,55
# Example for a steam locomotive# Coal, kg/km at calibration_speedfuel=10calibration_speed=75minimum_fuel_consumption_at_speed=30
# Example for a small early 'bus# Petrol, cl/km at calibration_speedfuel=20 # Equivalent to 14 miles per gallon, or 0.2l/kmcalibration_speed=50minimum_fuel_consumption_at_speed=15