SAS modules option to balance thrust.

[r4pt0r]

So I was thinking, would it be a good idea if the SAS modules could balance thrust by electronically limiting whatever engine it needed to?

With .25 having shuttle parts getting some love, I had the idea that the SAS modules get a special feature. You could right click them and toggle a "balance thrust" button.

When active, the module would control engine thrust so that the center of thrust remained behind the ships center of mass. This would help out shuttle designs that copy the real life shuttle.

maybe it could be a special feature of the SAS module with the green circuitry on the top/bottom. That ones gotta have computer stuff in it. EDIT: The IAS, forgot its name. It would be perfect for this.

Thoughts?

Edited September 3, 2014 by r4pt0r

[arkie87]

So I was thinking, would it be a good idea if the SAS modules could balance thrust by electronically limiting whatever engine it needed to?

With .25 having shuttle parts getting some love, I had the idea that the SAS modules get a special feature. You could right click them and toggle a "balance thrust" button.

When active, the module would control engine thrust so that the center of thrust remained behind the ships center of mass. This would help out shuttle designs that copy the real life shuttle.

maybe it could be a special feature of the SAS module with the green circuitry on the top/bottom. That ones gotta have computer stuff in it.

Thoughts?

I agree there should be an option for this built into KSP, and i would even say it should be enabled default so that beginners dont even notice the issues associated with placing engines slightly offset from CoM. However, there are several plugins that currently do this:

http://forum.kerbalspaceprogram.com/threads/67270-Throttle-Controlled-Avionics-1-3-0-23-5-(April-6)

http://forum.kerbalspaceprogram.com/threads/38069-0-24-Davon-Throttle-Control-systems-mod

Furthermore, with the addition of the vernier engines, it is easier to obtain necessary counter-torques to maintain stability (although it wastes fuel).

I think the best/most general solution would be tweakables which allow you to select whether engines are active under regular "thrust" and/or RCS. For instance, VTOL aircraft can be created using vernier engines with RCS turned on and using the IJKLHN keys. The obvious advantage of RCS is that its thrust is always applied at CoM (if possible). It would be better if we could set any engines to work with RCS and vice versa. Thus, for craft with asymmetry engines, (but engines at either side of CoM), they could be set to work with RCS and controlled with IJKLHN keys. However, the only problem with this is that IJKLHN are all-or-nothing and does not allow you to throttle your thrust. hmmm......

[Capt Snuggler]

I like this idea, but I think it should definitely be handled by an additional part like you say.

the Inline Advanced Stabilizer is kind of redundant these days and would be a good contender for being re-purposed.

call it a "thrust control computer"? that way it can be unlocked further down the tech tree and there will also be an additional weight and part count penalty.

*Edit:

and i would even say it should be enabled default so that beginners dont even notice the issues associated with placing engines slightly offset from CoM.

i would think this should be one of the first things a beginner should notice. if it where added it should be a high level part. unlocked in the mid to late game.

Edited August 26, 2014 by Capt Snuggler

[r4pt0r]

Yeah Capt Snuggler, that's the part I was referring to. It looks pretty smart(what with all that exposed circuitry) , so I thought it would be a good candidate for acting all computer-y.

[Kasuha]

Such feature would be extremely cool, in many situations. For instance if you break off an engine in accident. Or if you accidentally run out of fuel in one of tanks due to wrong fuel routing. And it would of course allow some crazy designs that are today impossible or at least very hard to make - such as asparagus with staging tanks one by one, not in pairs.

I even think there's no reason to introduce/repurpose a part for it. Particularly because it would be most useful exactly in cases where you need it due to an accident.

[Red Iron Crown]

I like the general idea, I've used Throttle Controlled Avionics in the past and enjoyed it (it actually does more than compensate for imbalances, it also provides attitude control via differential thrust).

Question: How would the system manage the varying fuel consumption rates? E.g. if you had a quadcoupler with four identical stacks under it and an imbalanced payload, one or more of the stacks will run out of fuel before the others. When using TCA I just added TAC Fuel Balancer, but that obviously shouldn't be required for a stock mechanic. Should something like it be included too?

[Kasuha]

Question: How would the system manage the varying fuel consumption rates? E.g. if you had a quadcoupler with four identical stacks under it and an imbalanced payload, one or more of the stacks will run out of fuel before the others. When using TCA I just added TAC Fuel Balancer, but that obviously shouldn't be required for a stock mechanic. Should something like it be included too?

Imbalanced payload would have slight tendency to balance itself - the heavier side would need more thrust, use more fuel and become lighter.

Of course in certain stage nothing can be done, then the algorithm should display some kind of warning.

And the function should be probably switchable separately as sometimes asymmetric thrust may be intentional.

[Capt Snuggler]

I even think there's no reason to introduce/repurpose a part for it. Particularly because it would be most useful exactly in cases where you need it due to an accident.

a feature as advanced as this should definitely have a part and weight penalty.

[Murph]

I like this idea, but I think it should definitely be handled by an additional part like you say.

the Inline Advanced Stabilizer is kind of redundant these days and would be a good contender for being re-purposed.

Sorry, but it's a terrible idea to re-purpose the IAS like that. It would break people's existing craft and saves for no good reason. If it needs to be done as a part, introduce a new part for it, leave existing parts alone (other than balancing them). Also, the IAS isn't redundant at all, it provides the middle of 3 levels of choice for torque modules.

[SiliconPyro]

I agree, this would be a nice vanilla feature. Fuel balancing would also be very nice, maybe the ability to assign several tanks to a group that all drain equally (assuming you've added proper fuel hoses). There has been some talk of changing how fuel transfer works in the future, so maybe balancing will get added at the same time.

[Capt Snuggler]

Sorry, but it's a terrible idea to re-purpose the IAS like that. It would break people's existing craft and saves for no good reason. If it needs to be done as a part, introduce a new part for it, leave existing parts alone (other than balancing them). Also, the IAS isn't redundant at all, it provides the middle of 3 levels of choice for torque modules.

I don't think it would break existing craft, at most you would loose some torque and gain stability when engines are burning.

but even if it did break peoples craft, the game is in alpha. peoples craft are likely to be broken and broken again on the way to KSP v1.0. the next patch v0.25 is likely to break many peoples craft when mk2 and mk3 space plane parts are all changed. thats progress

I agree, this would be a nice vanilla feature. Fuel balancing would also be very nice, maybe the ability to assign several tanks to a group that all drain equally (assuming you've added proper fuel hoses). There has been some talk of changing how fuel transfer works in the future, so maybe balancing will get added at the same time.

Yeah agreed, fuel balancing would be nice but again I think there would need to be a part and weight penalty for such advanced features.

A simple balance pipe would be nice that maintains the same % across the connected tanks.

[Murph]

I don't think it would break existing craft, at most you would loose some torque and gain stability when engines are burning.

but even if it did break peoples craft, the game is in alpha. peoples craft are likely to be broken and broken again on the way to KSP v1.0. the next patch v0.25 is likely to break many peoples craft when mk2 and mk3 space plane parts are all changed. thats progress

You're completely wrong there. It would break a large number of my craft, those where the majority of the torque comes from the IAS. Many of those craft have no need for thrust balancing (and are actually impossible to balance like that), having only a single rocket engine aligned with the CoM, and it would add no stability to them to replace the lost torque. The game being alpha is no justification for recklessly breaking existing saves, when it's just as easy to add a new part for the purpose and leave existing widely used parts alone. There's a very clear negative from re-purposing the IAS, and no negative from introducing a new part for the new purpose.

When there is truly no alternative to breaking existing craft and saves, sure that's a necessary cost of progress. In this case, there's a very clear and relatively easy way to avoid breaking anything.

[r4pt0r]

it could use someway of being more different from the other 1.25m sas thing though.

[Capt Snuggler]

You're completely wrong there. It would break a large number of my craft, those where the majority of the torque comes from the IAS. Many of those craft have no need for thrust balancing

*snip*

so what are you going do when the max thrust and isp of engines get balanced? or the mass or price of parts? or the torque value?

all my craft are constantly being "broken" by updates. so what. as long and the craft file can still be loaded in to the VAB, you can modify it and update it.

but hey why not leave the torque value in and just add in the thrust balance function with a price and mass increase?

the only reason I even proposed repurposing the IAS is that the mesh and texture makes it look like a far more complex device than it actually is, compaired to the other SAS modules.

*edit:

or what about when the atmospheric drag values get updated from the current, crazy system where it is based off the parts mass. a system that is clearly a place holder, and needs to be updated. (empty tanks have less drag than full tanks, causing strange behavior)

the "don't break my craft files" argument really bothers me because the game is full of things that will cause craft breakage when they get revised. I wouldn't want any old, broken, obsolete, placeholder systems or assets kept in just because some people don't want to build new ships.

Edited September 3, 2014 by Capt Snuggler

[Kasuha]

the Inline Advanced Stabilizer is kind of redundant these days and would be a good contender for being re-purposed.

http://wiki.kerbalspaceprogram.com/w/images/thumb/7/72/Inline_advanced_stabilizer.png/190px-Inline_advanced_stabilizer.png

By the way, IAS is not redundant anymore, it has been changed for 0.24. Now it is superior to IRW - less mass, more torque, higher price, later in tech tree.

[Murph]

so what are you going do when the max thrust and isp of engines get balanced? or the mass or price of parts? or the torque value?

all my craft are constantly being "broken" by updates. so what. as long and the craft file can still be loaded in to the VAB, you can modify it and update it.

but hey why not leave the torque value in and just add in the thrust balance function with a price and mass increase?

the only reason I even proposed repurposing the IAS is that the mesh and texture makes it look like a far more complex device than it actually is, compaired to the other SAS modules.

*edit:

or what about when the atmospheric drag values get updated from the current, crazy system where it is based off the parts mass. a system that is clearly a place holder, and needs to be updated. (empty tanks have less drag than full tanks, causing strange behavior)

the "don't break my craft files" argument really bothers me because the game is full of things that will cause craft breakage when they get revised. I wouldn't want any old, broken, obsolete, placeholder systems or assets kept in just because some people don't want to build new ships.

There's a massive difference between adjusting the balance of existing parts, compared to completely removing existing functions from them. There's simply nothing gained here by removing the IAS from the game (which is basically what you were proposing), but there is a very tangible negative to doing so. Adding additional functionality to it, no problem. Removing the widely used functionality just doesn't make any sense to me, when it would be extremely quick and easy to just add a new part for the new purpose.

I'll repeat what I said earlier. Sometimes there is no realistic alternative to breaking existing craft and saves, it's a necessary cost of progress. This is absolutely not one of those situations, as there's absolutely no reason why the IAS needs to be removed for this suggestion to go forward. There's nothing obsolete, broken, redundant, etc here.

[r4pt0r]

theres no need to remove it I think. make it a hair more expensive, and let it also have the toggle-able balance thrust option.

just like adding the suspension option to the landing gear, that didn't break all the saved craft with landing gear. Its just a new feature for a part that is essentially the same as the other small sas module. makes it clearly superior, but offset by its cost.

edit: Ive edited the OP to clearly reflect that my idea is to add this feature to the IAS

[Capt Snuggler]

forget it. we are now off topic.

point is, a thrust balancing module part would be a cool addition to the stock game. another great part to unlock higher up the tech tree.

what if instead of making it a central thrust control computer part thingy, instead what if it was a part you attach the engine to directly? so it would sit above each engine you want to be thrust controlled. make them quite thin and strong. its essentially an auto throttle for the engine attached to it.

rest of craft > thrust balance controller > engine

essentially it would allow you to turn any engine in to a Vernor Engine but by throttling its thrust.

Edited September 3, 2014 by Capt Snuggler

[Majorjim!]

Couldn't this function be an unlock-able for probe parts and cockpits? Then you can toggle it with the right click menu.

Like a systems upgrade in the tech tree. It shouldn't have weight as something like this would only be software.

[DundraL]

http://forum.kerbalspaceprogram.com/threads/66593-Throttle-Controlled-Avionics

Thats a mod I once used that does exactly as you say. changing throttle on engines for turns. But be warned: there is terrible side effect. If you turn in the same direction often, you will burn more fuel on one side of your ship, causing a weight imbalance, burnings lots of fuel just to balance things out again. if you Turn in the same direction too often, you will have to stop and transfer fuel just to fly straight enough to overcome the imbalance... by burning more fuel. Great on early takeoff, and a possible nightmare in space.