Algebraic Firing Solution - Page 2

TorpX · 02-24-13, 03:17 PM

I hope at least a few people have been able to make some use of this. In order to make the calculations less objectionable and time consuming, I've come up with a program that will crunch the numbers and display the results in a pleasing way. (30 minutes to do the math and 30 hours to get it to display right, lol.)

I know Gamefront and others have had their issues and not everyone can access these sites. Does anyone have any advice about how/where I could upload this for public use?

CapnScurvy · 02-24-13, 10:29 PM

What's the size of the download?

SubSim's "Downloads" server can handle about 40Mb or so. Anything larger Neil has an FTP site that's available for the asking. I've got two of my mods there (about 200 Mb each). The trouble with the FTP server is there seems to be a limit on how much your account holds. I've tried uploading a third mod of 200Mb+ with no luck. The upload freezes. I've attempted to get an answer from Neil about the FTP account limit but he's never got back to me.

Just a guess, but I'd think your mod could work on the regular SubSim's "Downloads" server.

Carrollsue · 02-24-13, 10:32 PM

Quote:

Originally Posted by TorpX

I hope at least a few people have been able to make some use of this. In order to make the calculations less objectionable and time consuming, I've come up with a program that will crunch the numbers and display the results in a pleasing way. (30 minutes to do the math and 30 hours to get it to display right, lol.)

I know Gamefront and others have had their issues and not everyone can access these sites. Does anyone have any advice about how/where I could upload this for public use?

I for one, have use it just to look at and understand what was going on, then altering it to see if I could come up with something I could use that faster. Bottom line, it shows everything about targeting, key for me SHOWS

TorpX · 02-24-13, 11:34 PM

Quote:

Originally Posted by CapnScurvy

What's the size of the download?

...

Just a guess, but I'd think your mod could work on the regular SubSim's "Downloads" server.

It will be less than 3Mb. However, I have in mind some projects afterwards that I would like to offer. They would probably be of similar size. Also, it might be necessary for me to make adjustments or improvements.

TorpX · 02-24-13, 11:40 PM

Quote:

Originally Posted by Carrollsue

I for one, have use it just to look at and understand what was going on, then altering it to see if I could come up with something I could use that faster. Bottom line, it shows everything about targeting, key for me SHOWS

I'm glad it is of some value. It took some time for me to get the diagrams squared away, but I knew that outlining the method without some decent diagrams would only lead to confusion. It is very hard to learn anything about geometry and trig without drawing it out.

CapnScurvy · 02-25-13, 08:45 AM

Quote:

Originally Posted by TorpX

It will be less than 3Mb. However, I have in mind some projects afterwards that I would like to offer. They would probably be of similar size. Also, it might be necessary for me to make adjustments or improvements.

On the "Downloads" main page you'll find the link to PM Neil directly regarding getting access to upload your mod(s). Once done and approved, you'll be able to add as many as you like, or edit an existing one anytime.

Armistead · 02-25-13, 11:50 AM

Great job Torpx.

Carrollsue · 02-25-13, 09:00 PM

Check out the post Zero gyro shooting it is a high-quality effort to a hard subject.

TorpX · 02-25-13, 10:17 PM

OK. I've PM'd Neal and while we're waiting to get word back, I'll give you all a peek:

So there is no confusion; this is not a mod, but rather a utility to calculate a firing solution using the method outlined at the beginning of the thread. It should work on any Windows machine. We'll have to see about Win. 7 and Win. 8, though.

Here are a few features:
has resizable window

can change display font

can use yards or meters

can calculate stern tube solution

also calculates collision course speed

It turns out, it is only about 1mb when compressed. Does anyone know if something like this can be sent by email or PM?

Carrollsue · 02-26-13, 02:17 AM

Quote:

Originally Posted by TorpX

So there is no confusion; this is not a mod, but rather a utility to calculate a firing solution using the method outlined at the beginning of the thread. It should work on any Windows machine. We'll have to see about Win. 7 and Win. 8, though. Here are a few features:has resizable window can change display font can use yards or meters can calculate stern tube solution also calculates collision course speed It turns out, it is only about 1mb when compressed. Does anyone know if something like this can be sent by email or PM?

Is that a handy-dandy MoBo??? WOW…WOW anyway, like what I see

TorpX · 02-27-13, 01:00 AM

Well, Neal has generously OK'd the uploading and I've got it all squared away. (I think it's ready, anyway.)

I haven't used MoBo, but I think that is intended to fulfill a different purpose.

This program will allow the user to manually calculate a zero-gyro angle firing solution, with a minimum of fuss. It uses the equations that I posted at the beginning of the thread. I have incorporated some changes and additions to make the process easier, however. I coded the angle inputs so the user can enter the relative target bearing 'as is'; there is no need to re-orient the angle. Likewise, there is no need to use a negative value for the sub speed when making a stern shot. Output angles are properly oriented and times are displayed in minutes and seconds. Also, one can easily change from yards to meters; so it is Kriegsmarine friendly.

The most difficult element I had to deal with (besides all the intricate never ending display changes), was putting in a series of logic checks to reject any sets of data that didn't allow a solution. It is probably not apparent why this would be needed, but I decided that it would be a substantial shortcoming if it were left undone. For example, if you are closing the target ship's track, bow on you can calculate the solution and it will give you the right answers. No sweat, right? But, at least in some cases, you could enter the same data and hit the "stern" button and get a false solution. Not good. Normally, this would be obvious from the plot, but if you weren't making the plot or were in a hectic and confused situation you might take it at face value. This bothered me, so I put in code which (I think) will catch all of these cases. One limitation remains from the original equations; you must still cross the target's track before you compute a solution for a stern shot. You can, of course, extrapolate your plot and compute a solution that way, but the program itself can't do it. I was going to put this capability in, but it would require another branch of code, and I decided to "keep it simple".

I added auxiliary calculations for collision course speed and optimum track angle. I had reservations about these. They aren't really required, but no extra data input is required and it wasn't difficult to add them. I think it is better to have capability in one utility, than maybe have to use another item/device.

I will probably present an example or two of it's use when I have more time, but it is fairly simple as long as you understand the definitions of track angle, etc., etc.

It can be found in the Utilities section of SubSim Downloads:

http://www.subsim.com/radioroom/down...o=file&id=3978

TorpX · 03-01-13, 11:23 PM

OK, no comments yet. I'm not sure whether that's good or bad.

In case anyone is having trouble with this, or readers are still a little unclear about AFS I, I've posted some examples, screen shots and explanations.

Here goes!

Target Track is in red
Sub Track is blue
Torpedo Track is orange (pink?)
bearing lines in black
angles in Gray

Case 1:

Target ship is on a closing track and will cross in front of Sub. At U0, Sub makes final observation before computing firing solution for BOW shot. Note in particular the Target bearing and Track angle. The bearing is obvious, but be careful about the Track angle. These two angles are all you have to worry about. The AoB is shown here only for reference, you don't use it in this method.

At U1, Sub launches torpedo, Target is at T1. Torpedo hits Target at T2.

Here is the corresponding firing solution:

Case 2:

Below is another BOW shot set-up. The main reason I am using this as an example is that this shows the Target is crossing from the opposite side and the Track angle is negative. This is important because the Track angle format is -180 to +180. If you use the wrong sign, you will not get the correct solution. Either you will get an error or wrong numbers. The program is designed to reject such cases.

And the solution:

Case 3, below:

Set-up for a STERN shot. I am assuming here that there is no option for a BOW shot for some reason. The Sub will cross in front of the Target ship, but has not done so, yet. There is nothing wrong with the set-up per se, only that the program wasn't designed to due this math.

And the screenie:

Case 4, below:

This is the 3rd case after the Sub has crossed the Target's Track. Now the firing solution can be computed. Note how the geometry has changed.

And the computed solution:

The computed information on the left, the optimum track angle and the collision course speed are not necessary, but I included them for reference since no additional data is required. The program actually uses the CCS to check if a solution is possible. The OTA is only for reference.

The program will not compute solutions for 0 or 180 degree Track/Bearing angles as this creates a divide by zero problem.

I would encourage people to get some scratch paper and sketch out a few set-ups just to see how it works and learn it. You don't have to go on patrol to do this.

Any feedback would be welcome. I am especially interested to hear what people like or dislike about the display. This is what I spent most of my time on and what proved to be most difficult.

TorpX

Dorjun Driver · 03-02-13, 10:25 AM

TorpX,
It’s not clear to me why your application doesn’t generate at least a partial firing solution for Case 3, i.e. the lead angle, which is all one really needs. Ceteris paribus. Given the target speed (VShip) , the torpedo speed (VTorpedo), and the interception angle (θIntercept) (180°-track angle (θTrack)), the desired lead angle (θDeflection) drops into your lap. See my Zero gyro shooting.

I admire the work you’re putting in on this topic.

Please keep it up.

Dorj

Beardmoresam · 03-02-13, 01:03 PM

Doesn't the TDC do this for you?

Edit:
To clarify what I mean is: I do this with the TDC all the time? I just turn off the PK and enter the predicted variables for the target and it does all this anyway? I find you just have to feed it the right info and it can give you a very accurate static solution just as much as it can give you a dynamic one.

Dignan · 03-02-13, 04:32 PM

Any way you can make this an iphone app?

02-24-13, 03:17 PM	#16
TorpX Silent Hunter Join Date: Sep 2010 Posts: 3,975 Downloads: 153 Uploads: 11	I hope at least a few people have been able to make some use of this. In order to make the calculations less objectionable and time consuming, I've come up with a program that will crunch the numbers and display the results in a pleasing way. (30 minutes to do the math and 30 hours to get it to display right, lol.) I know Gamefront and others have had their issues and not everyone can access these sites. Does anyone have any advice about how/where I could upload this for public use?

02-25-13, 11:50 AM	#22
Armistead Rear Admiral Join Date: Dec 2008 Location: on the Dan Posts: 10,864 Downloads: 364 Uploads: 0	Great job Torpx. __________________ You see my dog don't like people laughing. He gets the crazy idea you're laughing at him. Now if you apologize like I know you're going to, I might convince him that you really didn't mean it.

02-25-13, 09:00 PM	#23
Carrollsue Old man of the Sea Join Date: Oct 2009 Location: Imus, Philippenes Posts: 58 Downloads: 1288 Uploads: 0	check out ZGS Check out the post Zero gyro shooting it is a high-quality effort to a hard subject.

02-25-13, 10:17 PM	#24
TorpX Silent Hunter Join Date: Sep 2010 Posts: 3,975 Downloads: 153 Uploads: 11	OK. I've PM'd Neal and while we're waiting to get word back, I'll give you all a peek: So there is no confusion; this is not a mod, but rather a utility to calculate a firing solution using the method outlined at the beginning of the thread. It should work on any Windows machine. We'll have to see about Win. 7 and Win. 8, though. Here are a few features: has resizable window can change display font can use yards or meters can calculate stern tube solution also calculates collision course speed It turns out, it is only about 1mb when compressed. Does anyone know if something like this can be sent by email or PM?

02-27-13, 01:00 AM	#26
TorpX Silent Hunter Join Date: Sep 2010 Posts: 3,975 Downloads: 153 Uploads: 11	AFS I is ready! Well, Neal has generously OK'd the uploading and I've got it all squared away. (I think it's ready, anyway.) I haven't used MoBo, but I think that is intended to fulfill a different purpose. This program will allow the user to manually calculate a zero-gyro angle firing solution, with a minimum of fuss. It uses the equations that I posted at the beginning of the thread. I have incorporated some changes and additions to make the process easier, however. I coded the angle inputs so the user can enter the relative target bearing 'as is'; there is no need to re-orient the angle. Likewise, there is no need to use a negative value for the sub speed when making a stern shot. Output angles are properly oriented and times are displayed in minutes and seconds. Also, one can easily change from yards to meters; so it is Kriegsmarine friendly. The most difficult element I had to deal with (besides all the intricate never ending display changes), was putting in a series of logic checks to reject any sets of data that didn't allow a solution. It is probably not apparent why this would be needed, but I decided that it would be a substantial shortcoming if it were left undone. For example, if you are closing the target ship's track, bow on you can calculate the solution and it will give you the right answers. No sweat, right? But, at least in some cases, you could enter the same data and hit the "stern" button and get a false solution. Not good. Normally, this would be obvious from the plot, but if you weren't making the plot or were in a hectic and confused situation you might take it at face value. This bothered me, so I put in code which (I think) will catch all of these cases. One limitation remains from the original equations; you must still cross the target's track before you compute a solution for a stern shot. You can, of course, extrapolate your plot and compute a solution that way, but the program itself can't do it. I was going to put this capability in, but it would require another branch of code, and I decided to "keep it simple". I added auxiliary calculations for collision course speed and optimum track angle. I had reservations about these. They aren't really required, but no extra data input is required and it wasn't difficult to add them. I think it is better to have capability in one utility, than maybe have to use another item/device. I will probably present an example or two of it's use when I have more time, but it is fairly simple as long as you understand the definitions of track angle, etc., etc. It can be found in the Utilities section of SubSim Downloads: http://www.subsim.com/radioroom/down...o=file&id=3978

03-01-13, 11:23 PM	#27
TorpX Silent Hunter Join Date: Sep 2010 Posts: 3,975 Downloads: 153 Uploads: 11	OK, no comments yet. I'm not sure whether that's good or bad. In case anyone is having trouble with this, or readers are still a little unclear about AFS I, I've posted some examples, screen shots and explanations. Here goes! Target Track is in red Sub Track is blue Torpedo Track is orange (pink?) bearing lines in black angles in Gray Case 1: Target ship is on a closing track and will cross in front of Sub. At U0, Sub makes final observation before computing firing solution for BOW shot. Note in particular the Target bearing and Track angle. The bearing is obvious, but be careful about the Track angle. These two angles are all you have to worry about. The AoB is shown here only for reference, you don't use it in this method. At U1, Sub launches torpedo, Target is at T1. Torpedo hits Target at T2. Here is the corresponding firing solution: Case 2: Below is another BOW shot set-up. The main reason I am using this as an example is that this shows the Target is crossing from the opposite side and the Track angle is negative. This is important because the Track angle format is -180 to +180. If you use the wrong sign, you will not get the correct solution. Either you will get an error or wrong numbers. The program is designed to reject such cases. And the solution: Case 3, below: Set-up for a STERN shot. I am assuming here that there is no option for a BOW shot for some reason. The Sub will cross in front of the Target ship, but has not done so, yet. There is nothing wrong with the set-up per se, only that the program wasn't designed to due this math. And the screenie: Case 4, below: This is the 3rd case after the Sub has crossed the Target's Track. Now the firing solution can be computed. Note how the geometry has changed. And the computed solution: The computed information on the left, the optimum track angle and the collision course speed are not necessary, but I included them for reference since no additional data is required. The program actually uses the CCS to check if a solution is possible. The OTA is only for reference. The program will not compute solutions for 0 or 180 degree Track/Bearing angles as this creates a divide by zero problem. I would encourage people to get some scratch paper and sketch out a few set-ups just to see how it works and learn it. You don't have to go on patrol to do this. Any feedback would be welcome. I am especially interested to hear what people like or dislike about the display. This is what I spent most of my time on and what proved to be most difficult. TorpX Last edited by TorpX; 03-01-13 at 11:30 PM. Reason: screen shot flaw

03-02-13, 10:25 AM	#28
Dorjun Driver Loader Join Date: Jul 2012 Location: The Upper Left Edge Posts: 81 Downloads: 77 Uploads: 0	TorpX, It’s not clear to me why your application doesn’t generate at least a partial firing solution for Case 3, i.e. the lead angle, which is all one really needs. Ceteris paribus. Given the target speed (VShip) , the torpedo speed (VTorpedo), and the interception angle (θIntercept) (180°-track angle (θTrack)), the desired lead angle (θDeflection) drops into your lap. See my Zero gyro shooting. I admire the work you’re putting in on this topic. Please keep it up. Dorj

03-02-13, 01:03 PM	#29
Beardmoresam A-ganger Join Date: Oct 2011 Posts: 71 Downloads: 412 Uploads: 0	Doesn't the TDC do this for you? Edit: To clarify what I mean is: I do this with the TDC all the time? I just turn off the PK and enter the predicted variables for the target and it does all this anyway? I find you just have to feed it the right info and it can give you a very accurate static solution just as much as it can give you a dynamic one.

03-02-13, 04:32 PM	#30
Dignan Seasoned Skipper Join Date: Mar 2008 Posts: 698 Downloads: 262 Uploads: 0	Any way you can make this an iphone app? __________________