Navigation not exactly along the track

Norbert Josten shared this problem 9 months ago
Solved

Screenshot1:

You see the blue line from an imported gpx-File with few position-points.

I marked the position-points with red circles.

Screenshot2:

Switch on navigation. You see the wide purple line.

In screenshot2 I marked the same position-points with red circles.

But there are additional kink points, marked with "???", unusable.

Best regards

Norbert

Comments (27)

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What navigation do you use ? Is possible the area was recently modified in OSM and the OSM routing data differ from the OSM data the map is based on ?


Can you provide the location coordinate or the link to it, to reproduce the problem ?

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Hi,

do you have any automatic recalculation ON? If yes then Libor's remark can be true.

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Probably by navigation based on trackshape, no router service involved.

@ Josten What Locus version in use ? In picture: Speed 0.2 kmh.

Navigation by actual Locus Pro 3.25.1 (Speedindication: 18kmh.)

Tested by +/- similar track. A simple short gpx in zip file and see:

3 x tcx course generated by Locus Navigation (Low/Medium/High)

1 x tcx reference generated by JavawaRTWtool (turninstruction trackpoint angle trigger > 50°)

Locus: ->Setting->Navigation->Advanced settings->Number of commands: None,Low,Medium,High.

Josten advise 1 : Or use "None" or use "High" ( A lot of instructions, displays some small trackchange)

@Menion, suggestion: Remove Low/Medium. As by actual development system by router is most important/popular.

Josten advise 2. Use imported gpx as template and by few 'clicks' using routerservice (Brouter or online) generates you a new track with correct and minimal instructions.

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Hello Michal,

1) I use the navigation in Locus: Tracks > bike > klick on the imported gpx-Track > klick the button navigation at the bottom > than word "Navigation" > than zoom on the current GPS-Point, where I am

2) Same problem with all Tracks. Any location coordinates.

3) recalculation OFF

4) Locus 3.25.5

5) Speed 0.2means: I stopped and made the two hardcopies (png-Files), one with Navigation, one without it (switch it off)

6) Locus: ->Setting->Navigation->Advanced settings-> Strict=OFF, Max=50m, Snap=OFF, Number for voice=Low, Two commands=OFF, End=ON

7) Brouter installed

Best regards Norbert

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Does it happen even for GPX tracks generated by BRouter or any other OSM based router ? Or just for track prepared manually or imported from other, non OSM based sources ?


As for the latter the navigation may not follow the track, in contrary to guidance. In such a case, or if not using OSM map, or if OSM map or routing data are old, results may be strange.


Is BRouter also configured to be used in Locus ? What profile ?

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So, really need that example imported (gpx) file pse....pse... share.

If indeed is imported simple (external) (gpx) track: By Push navigation: Generation by "not optimal" system based on trackshape. (Brouter installed or not.)

By trackshape: Do not select Low/Medium, as results in serious trackdisplay position changes. Recommand 'High' but (-) expect A LOT of commands !

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I have not used imported external tracks and shape based hints for ages, using the luxury of BRouter. :-)

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- GPX-Tracks generated on gpsies.com.

- BRouter was already installed. I tested some settings, no change.

- New Screenshots made at home. Location coordinates in water, the north sea.

First screenshot only with blue Line, caused of the imported file "Norbert-test.gpx".

Second, I switch on the "Navigation" in Locus. You see the wide purple line.

But with two additional kink points.

Best regards Norbert

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Hi Nobert. Nice example.

That excludes any (B)router (or family) clearly out of the game ;-)

Definitely by trackshape. By Locus used (older) imperfect system. (Compromises)

Locus generates (and displays) an artificial helper track in use for best turn order generation.

- System had to be functional for both low density AND high density imported tracks.

- System had to be able to determine Slight/Normal/Sharp turns,

Result:

The displayed artificial track is NOT a perfect copy of the original (adds extra/different positioned trackpoints)

SET 'High' creates a best similar (= not equal !) copy of original imported track.

@ Menion. Because fast evolution by intelligent (b)router remove/retire actual system ?

Who still use ? Replace by most simple basic system as used by (pc) Javawa RTwtool ?

Any single trackpoint that exceeds a user *free SET angle do generate a turn order.

* Free set: >50° is popular setting for cycling. = Compromise : As turns orders could be missed using high density tracks with a lot of "small angled individual trkpt's" around slow turns.

(-) Only generates basic Left/Right and final result succes do depend on import trackdensity.

(+) No trackchange !

In attachment: Resulting Navigation tcx track by the JavawaRTWtool.

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Hi Norbert,

I can't simulate the issue with your test route:

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Will you please share the problematic GPSies route here so I can test it? Thanks

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@ Michal. The example file is here:

http://help.locusmap.eu/topic/navigation-not-exactly-along-the-track#comment-44996

From my home position:

76a46d79d0e058fb36a872298eb41383

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Willy, I've tested the file - see the screenshot above. But Norbert reported a different file at the beginning - some imported from GPSies.com.

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This is what I download. = origin GPSies

Michal did you select: Number of commands "Low" ??

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ah, low number of commands set = issue simulated. Another task for Menion :) Thanks to all for reporting!

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Perfect ! I suggest: Simplification ! Remove set Low/Medium.

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Good day guys,

cannot say this is directly an "issue". In case of track with navigation and selected other then "none" in number of navigation commands settings, Locus automatically generated new track with points after exactly same distance and then try to estimate navigation command suitable for certain area.

So simply, in case of selected "small number of commands", Locus Map generate new track based on source track with points exactly 30 metres between. And what you see is the result. What may happen in worst case, is around 15 m error, which I consider as really minor problem. Ok?

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No response ... anyway not a big problem in real life I believe. Closed.

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I was patiently waiting for a response too. No original example track available.

I created a +/- similar track design as shown in the screenshots.

See Locus 'low" result. (A nice opportunity to simplify Locus menu a little bit)

(Track tcx by Locus 'low' generation ->Displayed by external program)

57d5876458d91c4e82bbc3f3ea11d1d1


See the used example testfiles. The gpx design inclusive a "high" and a "low" result.

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Hello Willy,

difference between log & high seems to me quite big. What you suggest? To remove this settings completely and leave in app only "middle" option that will apply automatically?

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Correct.

My prefered setting always was (is): "High" (+) Most precise (-) Many commands

Simplify Menu:

Navigation -> Advanced settings -> Generate commands ? (Unset/Set button)

(If track contains no commands Locus will generate for you)

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Little complicated task to be true. "High number of commands" is usually very talkative, but are situations when it's useful to have really often instructions.

I'll keep this in mind, but for now I'll leave as is. Thanks for understanding.

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Hello Michal,

I don't use voice-commands. Currently I only use the purple route-line on the screen.

Negative: This purple route-line has additional kink points.

New examples.

Best regards

Norbert

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Hi Norbert,

this situation occurs when the route is drawn with just a few routepoints (not a case of automatic router assisted routes with thousands of rtpoints) and number of commands set "LOW".

If you don't use navigation commands , set them as "NONE" in Locus settings > Navigation > Advanced > Number of commands.

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Hello Michal,

with "NONE" it works. But my friend would like to navigate with commands, therefore I could not recommend Locus to him.

Now I set commands back to "LOW". Than I create two new tracks, one with less points and the other with automatic generated additional way-points (see Hardcopy). With navigation and more waypoints you see still kink-points from Locus, not in the gpx-data.

The error is complicated, isn't it?

Best regards

Norbert

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Hi Norbert,

as Menion wrote here 4 months ago, Locus navigation commands generator works like this - it creates a copy of the route and optimizes according to assigned navigation commands. The "kink" points you report is a side effect of this process. The more navigation commands you set, the more similar is the navigated route but the high number of commands can be annoying. If you know any method of developing a navigation command generator without this side effect, please let us know.

EDIT by @menion: so try HIGH, this should help here.

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Hello Michal,

in other navigation systems, like HERE-WeGo, sometimes the voice-command for "turn left" or "turn right" is too early or too late. But on the map you see the correct way in the navigation. This navigation follows the streets.

It is different to Locus's internal navigation with gpx-data:

– This kind of navigation does not follow streets and ways. (You remember, the "kinks" are also in a gpx-track on the north sea.)

– The purple route-line AND the voice are generated by command generator from the gpx-track data.

Is it necessary in Locus, that the voice-commands and the purple route-line are coupled ?

What do you think about, only the voice generates by command generator. Than, the purple route-line shows the gpx-track-data directly. I think, Locus needs the generator only for thin or bold figure of the purple route-line.

Best regards

Norbert

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Good day Norbert,

as a main app developer, I'll try to explain here what is necessary. Locus use own internal generator for GPX tracks as mentioned here. This generator not just generates navigation commands, it also generates trackpoints along original route in defined interval. For low number of commands, this interval is equal 30 m. So in case of this option, it is possible that these 30 metres cause visible "shortcut" on the map.

It is necessary to consider that error will be in worst case around 10 - 15 metres and precission of GPS is usually somewhere between 5 - 10 metres, so real error will be really slow. If this is a problem, as I mentioned in Michal's post, you may use HIGH parameter for generating navigation commands, which cause interval to be only 5 metres and error, even on map, will be hardly significant.

Separating generating of commands and drawing of line on map is not possible. Thanks for understanding.

Menion

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