AI train refusing to depart despite line ahead clear

[RobKi]

[solved] AI train refusing to depart despite line ahead clear

Another AI mystery (to me anyway). I set up a session where a passenger train

• begins by waiting in a siding for 30 seconds,
• then proceeds to track marker Spv-1 which is in a platform track,
• then waits there for 30 seconds.

So far, so good, the train gets there by itself. It is the only train on the line. The station platform is not a functional one.

The next command, after the 30 second wait at the platform, is:

• drive to track marker G-P-1,

which is a couple of miles down the (single) line. All signals between the train and that track marker say 'line ahead is clear'. Yet the train simply continues waiting at the platform. I once waited for 20 minutes to see whether the AI needed that time for something, but nothing happened.

Here comes the strange thing. I hop into the cab of the train and move the throttle up a few notches, then ctrl-rightclick and tell it to "continue schedule". The train departs and carries out all of its remaining twelve instructions without further human intervention: proceeds to track marker G-P-1, continues to the end of the line, reversing, returning to the place where it started, and waits in the siding to repeat the instructions.

The route was originally built for Trainz 2012 and everything functions well when trains are operated manually in TANE.

Can anybody shed any light on why the train is not departing automatically from track marker Spv-1?

 

[KotangaGirl]

At a guess without knowing how your signals are placed I would say there is something about their positioning that the AI doesn't like. I've had the same thing while doing final adjustments on my own GER layout running in TS2012 where an engine won't move, but once started off and it has passed the first signal all is fine. I agree it's maddening when all signals are clear and an engine just sits there not moving. Sometimes the message box gives a clue, but usually it's not particularly helpful.

 

[JCitron]

What are the signals like ahead?

What messages do the drivers produce?

Does pressing pause, waiting a few seconds, and starting up again help?

With the latter point, there is a known bug, yes I submitted it and it's being looked into, where AI drivers just refuse to move after "sometime" but prodding them or pausing will get them active again. Saving the session and returning does the same, but there are other implications with that such as signals not coming alive, and other nice things occurring.

 

[RobKi]

Solved! Thank you for your pointers, KotangaGirl and JCitron.

It turned out that somewhere down the line there was a crossover, not used in normal service, where one of the junctions lacked a lever. Apparently that leaves the AI undecided: no lever, no data about the switch setting, no action. I also noticed that although all signals appeared to say 'line ahead is clear', only the signal before the crossover remained at danger.

I added a lever to the junction, saved the route, and re-started the session. It works! The train now takes off after 30 seconds' wait, just as ordered.

 

[JCitron]

Solved! Thank you for your pointers, KotangaGirl and JCitron.

It turned out that somewhere down the line there was a crossover, not used in normal service, where one of the junctions lacked a lever. Apparently that leaves the AI undecided: no lever, no data about the switch setting, no action. I also noticed that although all signals appeared to say 'line ahead is clear', only the signal before the crossover remained at danger.

I added a lever to the junction, saved the route, and re-started the session. It works! The train now takes off after 30 seconds' wait, just as ordered.

Excellent to hear. Did the driver message say unable to plot route, junction missing lever?

The signals will be green if the AI have chosen another track to take. The problem then is the AI still can't get to their destination because they are no going a different way on another track.

 

[llebrez]

Definitely there is a bug somewhere on this. The solved problem makes sense. But what about when on first run the trains pass all the lines and waits as intended, after meticulous pre-programing. Save the session, and when you run it again, one train do the same as observed on this thread: It sits there waiting. When you put the cursor over the signal, it says something as overlaping signal. But it was not overlaping on the first run! Doing a deep search, I find that some turnouts have changed from the default position, and these, being 2 or 3 turnouts ahead, would not change for the path intended by the AI. Manually clicking them for correct path, and the train moves! Some could say, use IT's, but why it works on first run and fails after saving a session? As you can see, one bug, here, alters several things down the line, in this case the fact that saving a session does not save exactly everything that should be saved. I think...

 

[JCitron]

Definitely there is a bug somewhere on this. The solved problem makes sense. But what about when on first run the trains pass all the lines and waits as intended, after meticulous pre-programing. Save the session, and when you run it again, one train do the same as observed on this thread: It sits there waiting. When you put the cursor over the signal, it says something as overlaping signal. But it was not overlaping on the first run! Doing a deep search, I find that some turnouts have changed from the default position, and these, being 2 or 3 turnouts ahead, would not change for the path intended by the AI. Manually clicking them for correct path, and the train moves! Some could say, use IT's, but why it works on first run and fails after saving a session? As you can see, one bug, here, alters several things down the line, in this case the fact that saving a session does not save exactly everything that should be saved. I think...

This is the threading bug that I mentioned above. The devs are greatly aware of that. Tony said that the AI logic needs a full rewrite. Maybe they should work on this first instead of new versions of anything.