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91
That seems to be working very well now.

If you think there are rounding errors in there somewhere, it would be interesting to compere the accuracy with the turrets built before XFM added inverse trig functions. They used an integrator with the projected trajectory calculations in the feedback path to home in on the best firing solution. That might have some inherent error cancellation or bigger numbers that are less affected by rounding.

We really need some bigger maps for ACL so that there's more chance to use snipers/long range artillery like your bot, or missiles and grenade cannons.
92
General Discussion / Re: Need info on plasma-projectiles
« Last post by MarvinMan on December 07, 2016, 08:03:23 pm »
My original combat bot has the full ballistics calculations implemented on its turret, if you want to look at that to see what sort of numbers work.

Lately, I've found that using something like 1/(range*altitude) to set the angle of cannons is a good enough approximation for ACL use.

For longer ranges, you can boost the projectile velocity of cannons by accelerating them with a piston as they fire. A rotary solution may work too, especially for a higher rate of fire, but I expect the aim will be poor and inconsistent.
93
General Discussion / Re: accurate & reliable way to launch stuff at a certain speed ?
« Last post by tob.s on December 07, 2016, 12:41:31 pm »
that idea seems promissing,, will give i a try
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General Discussion / Re: accurate & reliable way to launch stuff at a certain speed ?
« Last post by MarvinMan on December 07, 2016, 07:55:48 am »
Once it's in a stable flight path, you could have the grenades separate from the propulsion system to continue to the target in a regular ballistic arc.
95
General Discussion / You may run, but you cant hide from this extreme range plasma gun
« Last post by tob.s on December 07, 2016, 03:52:15 am »
Hi,

to hit something moving, you need to be able to hit a stationary target very precisely first.
i always used rel. simple geometrics to determine the launch angle of my cannons - so they were basicly pointing directly at the target ( with some offsets to counteract gravity for certain ranges ).
This time though i used ballistic calculations to proper include gravity and the result is  ;D , but see yourself.

edit=vd

I linked the target to the cannon, so i could fire it without having to switch between target and cannon, also added some distance-  and a *wip* time-to-target -display , targeting is using a camera imput though and isnt connected to any off the other stuff. Everything exept firing is full automatic, the target turns red whenever i press my fire key.

There seems to be a bit of a dead/lower accuracy spot when firing nearly horizontal, i guess its because many of the arc functions deliver values very close to zero - not sure if the "freezing" of any slow moving object also affects this - so in the video im firing short salvos. If the first shot doesnt, the second one hits ( seems like the physics have to be woken by the first shot). Also im currently not compensating the very small differnce between the set angle and the cannons actual pitch, which might also be the cause.

The Values i couldnt calculate are based on experiments and guesswork, so theres still room for improvement.
Next step will be to declutter / nicely arrange the vp-code and then figure out how to hit moving targets.


- edit-
with your help, some value tweaking and also by adding a controler to make sure the cannons pitch is exactly alignend to the calculated launch angle, i nearly doubled range. Now it hits precisely between distances of 50 to 1000. Maximum shooting distance at the given speed  and 45 launch angle is around 1250 . However at more than 1000 range, the closer i get to max range, the increasingly earlier the projectiles drop. I tried changing the projectile speed in the calculations but it has no effect, so i guees it may be due to rounding &/ canon alignment errors.
video is being updated


96
General Discussion / Re: Need info on plasma-projectiles
« Last post by tob.s on December 07, 2016, 03:05:04 am »
thanks - after a lot of fiddling, i, pretty pleased with my result ( see seperate thread ), still im not 100% sure if those maths are correct or just happen to work under the tested conditions. Im not realy good at maths, so a lot of it is guesswork ( especialy when arc-functions are involved ). Currently im using a speed of 75,5 for my calculations - using half G.
At 1 Capaticy, the shot force is around 4000 - divided by 39,5 thats 101,2... ill give this a try together with 1g and see what happens.
97
General Discussion / Re: Need info on plasma-projectiles
« Last post by PressureLine on December 07, 2016, 01:32:49 am »
From memory you can take the shoot force and divide it by 39.5 (or a similar number) to get the velocity of the projectile. I do have a ballistic calculator level saved (it operates at about 0.8G though, like most blueshift-based maps) that I can upload tonight if you want.

For a combat bot I usually just pre-compute (using the ballistic calculator at a given capacitance and distance [usually 250]) then do
Code: [Select]
(distance to target/pre-computed distance)*pre-computed angleto get the superelevation angle, then do straight altitude based calculation to get the straight-line angle between the cannon and the target, add them together to get the total angle required. That will usually generate a hit on a bot-sized target at a reasonable range (just a reminder that this is based on using a blueshift-based map, where the distance between targets and the altitude difference is not affected by the spherical gravity field of a planet)
98
General Discussion / Need info on plasma-projectiles
« Last post by tob.s on December 07, 2016, 12:21:20 am »
Hi,

currently my plasma-turrets use triangulation or the altitude difference based maths for vertical aiming - both methods ignore gravity though, which easily could lead to missing even a stationary target at above medium distance.

so currently im trying to use the same ballistics i used to lob the grenades in the video below to aim with a plasma cannon. I determined the speed of the plasma by firing backwards from a plane - around a speed of 75 the plasma drops almost vertical from the plane, so i fed my maths with v=75. Also, plasma seems to be floating / not fully affected by gravity - i reduced it to half witch seems to work, to realy be sure ill need to build a much larger test-map though. Atm im still using the formula for targets at the same altitude, as the error is minimal when firing in an high arc.  Now with plasma though, the arc is very flat, so im currently searching for the correct formula.

as i renember, xfm tweaked the plasmas behaviour - so the correct values might have been posted somewhere back then. If someone knows the exact values it would be a big help.

99
General Discussion / Re: accurate & reliable way to launch stuff at a certain speed ?
« Last post by tob.s on December 06, 2016, 01:21:54 am »
basicly, i just added the fins to make the missile turn accourding to its flight path ( without, the missile would just keep the angle at wich it was launched as theres no air resitance) , so its mainly decorative and to see how much of a differnce the drag would make. One benefit though is that the missiles always hit with the grenade first, while without fins they would crash their rear into the ground short before the target, sometimes even making them bounce of target - as seen on this old bot
100
General Discussion / Re: accurate & reliable way to launch stuff at a certain speed ?
« Last post by MarvinMan on December 05, 2016, 08:26:16 pm »
Is there any articular objective for these missiles?

If adding some reverse thrust for trajectory changes is a workable solution, it wouldn't take much more to have a couple of control surfaces to constantly adjust the flight path.

If it's acceptable to have the missile spinning, it could be possible to steer with a pair of fins and a single elbow/motor.
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