Rework on voicehint process

[afischerdev]

It seems the post process for voicehint generation needs a rework.
Please see doc for voicehint for the current rules.

Related to this discussion in Cruiser forum we have some smaller irritation for the users (I hope I got it correct):

Sample	Result	Expected Result
1. sample	left, continue	left
2. sample	continue, left	left
1. sample with trekking	continue, left, continue, continue	left
3. sample u-turn	continue, u-turn-left, continue	u-turn-left
4. sample u-turn	u-turn-left	u-turn-left

The rule keep continue when bad way is on higher prio is working fine. But it has its side effects.

Are there any other examples that should be revised as well?

[afischerdev]

An other point for this rework is the handling of two near turn instructions left/right.
Here two examples
5 meter difference - result for all straight
7 meter distance - result for trekking right/left, for car straight

The different results come from the minimal distance table:
foot = 3m - with a speed of 5 km/h we have 1,4 m/s = 7 meter cost 5 seconds
bike = 5 m - speed 10 km/h - 2,8 m/s = 2.5 seconds
car = 20 m - speed 30 km/h - 8,3 m/s = 0.8 seconds
I don't know how long a sentence like 'turn left and follow for 7 meter' will take in audio but I guess on a car driving you will not hear very much.

[0709wiwiwi]

I don't know how long a sentence like 'turn left and follow for 7 meter' will take in audio but I guess on a car driving you will not hear very much.

The last announcement before turns should be very short and clear.
Example: (slow_speed)

• TTS by small distance: After 30 meters turn left (TTS)
• TTS last announcement: left (TTS) As compact as possible !
• TTS by small distance: After 30 meters track at 9 o’ clock (TTS)
• TTS last announcement: track at 9 (TTS) As compact as possible !
  Alternatively the last announcement as a loud and clear compact Morse beep “T” - “dash”
  Uploading Beeline_clock_sym_guiding.docx…

[afischerdev]

Two new samples from #625:

1. turn instruction left with starting straight
2. missing turn instruction sample

[afischerdev]

During my research for this issue I found further inconsistencies - like the number 2 above.
Some hints are dropped like this right instruction
This means to me it is not only a postprocess problem.

[afischerdev]

Sample 2 above:
in my eyes the exclusion of this voicehint is done in VoicehintProcessor.

boolean hasSomethingMoreStraight = (Math.abs(turnAngle) - minAbsAngeRaw) > 20.;
The angles are turnAngle= -88 minAbsAngeRaw= 180, so the result is -92

I didn't use a correction on this for now - just to keep the results comparable. But I used a new logic in post process.
In the past we had a collection of nearby voicehints, now I tried a comparing of two voicehints a time. This brings better results and make lost voichints visible.
Here a the results of differents on this track current logic against new one.

left = old

The source is located in my repo

Before I go on with the 'left' problem and the exclusion of the straight voicehints in nearby situation, I like to hear what you are thinking about. Is this a way it could go?

[quaelnix]

I did not expect the u-turn hint in the second last example and the two straight hints in the last example, but overall I think this is the way to go. However I don't understand the source from just looking at it. Maybe we should document the logic somewhere?

[devemux86]

@afischerdev seems like a working solution:

• We get the currently missing instructions (as shown in the right images)
• Then we can post-process them and exclude the nearby straight instructions

[afischerdev]

@devemux86
Please hang on a minute. I'll continue here in a few days.

[devemux86]

@afischerdev

A Beta version of Cruiser is available where I post process the turn instructions to fix the nearby "continue":

• Cruiser 3.0.37 (Beta) devemux86/cruiser#390 (comment)

(this works in Cruiser code on top of any routing service)

[afischerdev]

@devemux86
Hmm, interesting thing. Good to know that clients can protect that as well.
Anyway I think there is still some work for BRouter.

[devemux86]

More examples of routes missing a "turn left" instruction were reported:

• Dual carriageway and left turn, Continue instruction devemux86/cruiser#307 (reply in thread)

[afischerdev]

Next version for voice hints

The first step was to start a new transportMode - announced here #544
But this changes only the internal use, no changes in profile at the moment

To remenber the old rules from doc

• show 'continue' only if the way crosses a higher priority way
• roundabouts have an exit marker
• u-turn between -179 and +179 degree
• merge two hints when near to each other - e.g. left, left to u-turn left
• marker when highway exit and continue nearly same direction
• beeline goes direct from via to via point

There are two steps of control for the voice hint list:

• add voice hint to the list when it passes the first control
  rules are around the good way/bad way turn angles, priorities or link to highway
  only small changes here - e.g. enable the left turn (see above)

• remove voice hint from list when it passes the second control
  here we check the old rules (ignore roundabouts and beeline at the moment)
  these rules need some updates

  • show 'continue'
    only if the way crosses a higher priority way
    and ignore a possible second crossing
    and ignore on tranport mode car when near to an other voice hint
  • merge two hints when near to each other
    use e.g. left / left = u-turn only for transport mode car
    use e.g. left / right = straight only for minimal range (different on foot, bike, car)

Results for trekking samples above:

For a closer look:
Here are the comparable GPX files in new and old version. In the new versions the voice hints have an additional point name to have an easy entry for a point discussion.

testtrack0.trekking_old.gpx.txt
testtrack0.trekking_new.gpx.txt

testtrack0.car_old.gpx.txt
testtrack0.car_new.gpx.txt

testtrack0.hiking_old.gpx.txt
testtrack0.hiking_new.gpx.txt

The samples uses all the same coordinates Darmstadt to Heidelberg
Please don't look at the routing results, focus only to voicehints.

The source for this you find as before here

So have fun the next days.

[afischerdev]

For the new issue #664 I changed the voicehint calculation on roundabouts.
I did it in this repository because I'm on the way to do a PR for this new features.