[WAD / USER ERROR] Friendly AI: Tanker trying to refuel/ship formations stopping

[xenophanes]

Hi,

while playing through the Trans-Atlantic Convoy Duty scenario, I noticed some strange AI behaviour.
[ol]
[*]I set up a support mission for my tankers, 1/3rd rule active and units on station set to 1. This worked nicely for some time. When Sidewinders #2 (A-7E, CAP) bingo'd and wanted to refuel, he selected Panther Sweat #2 (KA-6D, Support) for refueling. But Panther Sweat #2 was bingo itself and tried to refuel from Panther Sweat #3 (which had plenty of fuel left). I had a save when this all started, but I accidentally overwrote it. Fortunately, the remaining save still pretty much conveys the problem: If you don't give any commands, both Panther Sweat #2 and Sidewinders #2 will RTB shortly, but Sidewinders #2 isn't going to make it to the carrier. (If he RTB'd at the right moment, he would have made it.)
You can find all mentioned aircraft 60nm north of the Nimitz CVBG in the save.
The main awkwardness is certainly that a tanker tried to refuel from a tanker in the first place - it doesn't take a tactical genius to figure out that this is nonsense! [:)]
[*]I set some of the Nimitz/convoy escorts to sprint and drift. When the escorts went from sprinting to drifting, the groups stopped completely, saying they are "reducing speed to regroup". After unchecking "Group lead can slow down (group reform)", the groups continue normally. Is this intended?
[/ol]

This is the first non-training scenario I play, so I hope the above can't attributed to my ignorance. [:)]

PS: In retrospect, it would have been better to assign the tanker mission to two RPs instead of one so that they don't circle.

[Tomcat84]

Not sure about point 2.

As for point 1, I think the next release candidate may have an extra doctrine option available or some other kind of fix to alleviate problems with tankers refueling each other inadvertently.

I do indeed find that it is better to build a tanker track with 2 or 3 RPs rather than a single one, makes it easier for planes to join up. I use three if I want to use "cruise" speed to transit and not loiter. Otherwise if you set that and use 2 RPs it will only go Loiter one direction of the track and then Cruise the other way (since it will think it is in transit again until it gets back to the first RP, make sense?)

[thewood1]

I think 2 is pretty self-explanatory as your wrote it. It is intended as its written isn't it? Am I missing something in your question?

[xenophanes]

Well, to explain more clearly: Take the convoy. It consists of some commercial RO/RO vessels and three frigates. I set the frigates to sprint and drift - doesn't make sense to have the commercial vessels sprinting and drifting! [:)] Now, the frigates will sprint at 30kts and the other will continue at 12kts - so far, so good. But not long after the frigates change to drifting at 0kts, the entire group, i.e. the escorts and the merchants will come to a full stop, indefinitely. Even after waiting some minutes, they don't move! The group lead reports that it is "reducing speed to regroup", and unchecking the "group lead can slow down" checkbox indeed makes the convoy continue.

[xenophanes]

Thanks, I implemented the three-RP setup and it works fine! Didn't find anything about the extra doctine option in the next RC though.

[Tomcat84]

Thats cause it hasnt been released yet. Should have been more clear sorry [:)]

[xenophanes]

No need to be sorry - I thought there was some public information regarding that doctine setting since you aren't a developer (are you?). I guess you're a beta tester of some sort?

[Tomcat84]

Yeah closed beta tester. Not a developer [:)]

[Rudd]

I haven't looked at your save but, I wonder what ship is the [LEAD]. Is it one of those frigates that are sprinting and drifting? Just a thought, probably should be one of the HVU

[xenophanes]

In case of the Nimitz CVBG, it's the Nimitz. In case of the convoy, it's one of the merchants.

[xenophanes]

I just discovered another tanker related issue: A S-3A Viking wanted to refuel, but since its cruise speed of 277 kts is lower than the tanker's (KA-6D Intruder), it will never reach it and eventually run out of fuel. Additionally, a F-14 will eventually "steal" its slot, making it RTB and even more likely to run out of fuel because it already spent its time refueling.
Furthermore, since the KA-6D is apparently much more agile than the S-3, it manages to turn quicker at the end of my 3-RP tanker setup (see above), making the S-3 lose even more time since it turns in a relatively huge circle. This leads me to believe that the best tanker setup would be some kind of a wide circle or a holding pattern commonly used in civilian aviation, but both would be rather tricky and RP-heavy to setup. May I suggest to introduce a mechanism to make an aircraft, especially a tanker, "hold" instead of just loiter at a RP? Maybe in the waypoint speed and altitude window?

Can provide save file if needed.

[Tomcat84]

If you make sure the KA-6 is set to a "loiter" speed, then at 12000 ft or above the S-3 will always be able to climb, get a speed advantage and catch up to it. And you can also use a multi RP track if you want to set it up for this specific instance.

Check attached scenario for a possibility. Order the S-3 to refuel. Should hook up reasonably fast.

[Tomcat84]

Build 739 now available:

tm.asp?m=3923060&mpage=5

It adds an extra option to the Refuel doctrine "Always, excluding tankers refuelling tankers"



If you set it to the new option the tankers should leave each other alone.

If you ever do want one tanker to refuel another, set the doctrine to Always for both of them.

[xenophanes]

I started your scenario and ordered the S-3 to refuel. It then climbed to 36000 ft and approached the tanker. But just before hooking up, it suddenly drops to 12000 ft in a fraction of a second. I think we just uncovered another bug! [:)] Unless this has been fixed in the Release Candidate, of course (I'm running v1.08).

I just checked the situation I mentioned in post #11 and realized that the Viking was at 25k ft and the tanker at 45k ft, so its the inverse situation and explains why the Viking has its speed problems.

[ComDev]

The problem is that you're only using a single ref point for the tanker's mission. The tanker is flying in circles around this ref point, making it difficult for the Viking to catch up. Adding a second ref point ca 50nm from the first resolves the issue.

[xenophanes]

emsoy, the issue I described in post #11 occured after I set up a three reference point setup as recommended by Tomcat84. I'm sorry for confusion, please let me clear it up.
Issues described in this thread:
[ol]
[*]Post #1, point 1: Tankers refueling from other tankers. This has obviously been fixed by the addition of a new doctrine option.
[*]Post #1, point 2: The save file referred to is the attachment in post #1. Ship formations which include vessels sprinting and drifting stop completely in the drift phase. Please also consider my more detailed explanation in post #4.
[*]Post #14: The save file referred to is Tomcat84's example scenario. Aircraft maneuvering to refuel generally approach the tanker and at some point are directly at the tanker, having the same speed and altitude. If you observe the S-3 after you order it to refuel, it will first climb to an altitude of 36k ft. Note that the tanker is at 12k ft. The Viking will continue to approach the tanker at the wrong altitude, but will instantly change its altitude to the tanker's when it "docks". It won't descend to 12k, it will just drop from one second to the other, so this is clearly some kind of a glitch.
[*]Post #11: This occurs after the save file in post #1. I didn't originally attach a save file to the post #11, but will attach it to this post. The situation here is the inverse of post #14: The tanker is high at 45k ft compared to the Viking at 25k ft. Because the Viking never climbs to 45k, it will never reach the tanker unless you manually set the speed to military or the altitude to 45k. If it automatically climbed to 45k ft as it should, everything would be fine.
[*]Suggestion in post #11: To make setting up tanker missions easier, it would be nice if you could let a tanker automatically fly a "holding pattern" instead of a simple circle. While this would greatly aid UI flow, it really isn't as important as the aforementioned problems.
[/ol]

Please do not hesitate to ask for further details, I will happily provide them! [:)]

Thank you very much for your support!

[ComDev]

Thanks for the clarification, much easier to follow now hehe [8D]

Have fixed #3 for B742, the aircraft will start to adjust to the tanker's altitude ca 5nm out. Have to be real careful here because the aircraft must fly to the tanker at the same altitude as they used to estimate the fuel required to reach the tanker. If flying to the tanker at lower altitudes (and higher fuel consumption) the aircraft run the risk of crashing out of fuel.

Will look at #4 next.

#5 is on my to-do list for the Advanced Strike Planner, along with CAP (0-figure) and AWACS (8-figure) tracks.

Sprint/drift fixes will have to wait for 1.10 I'm afraid. Horribly complext stuff and need more time to peal appart and fix.

[ComDev]

#4 was fixed by the correction made for #3 [8D]

[xenophanes]

Wow, that was a fast response! [:D] Thanks for the fix for #3.
#4 is essentially the same, so if you fixed #3, #4 should be fine too.

Slightly OT, but: I've heard of the Advanced Strike Planner several times in numerous sources, but since there's no "official" information on this and I'm a bit new to all this, I'm kind of confused to what it includes - is it about the Air-to-Ground aspect? Or more like an overall extension of the mission editor? Or something entirely different? [:)]

Anyway, thanks for the great support you guys provide!

[thewood1]

A search on "advanced strike planner" turns up several good threads where it is discussed. That might be a start.

searchpro.asp?phrase=Advanced+Strike+Pl ... button=+OK+