Free Routing Software. qtVlm

[Bowman62]

thank you for the answer
i tried in any way but it is always red . (i am using 3.3-5 . 3.4 does not keep the routes)
do I skip something ?

ad

[maitai]

Can you post a screen-shot?

[Bowman62]

see att

[maitai]

Ah ok sorry. The new version (not yet available) has a different dashboard and I confused both. In fact in this version the red color has no particular meaning, it's red just to see these values better. In the new version some values become red if you are not within the best-vmg range.

[Bowman62]

thank you

[Bowman62]

good morning Maitai,

is there any way to integrate the Grib file caming from a global service provider with the local weather forecast?

Grib files do not take care of islands and mountains as well as local land and sea breeze.

thank you in advance

adm

[maitai]

qtVlm can read almost whatever grib in grib1 format. We are working on the grib2 format but that won't be ready before a couple of months.

So assuming it's in grib1 format, you can purchase fine resolution gribs that are specialized in your area (for instance gribs by predictWind) and load them in qtVlm. Unfortunately such specialized gribs are not free.

[kiwisails]

Hi.

First, awesome product. I just have to get my boat polars.

1. GPS Setup
I am running Ubuntu 12.10 and have a BU-353-S4 USB GPS Receiver. Its using GPSD to communicate with OpenCPN and works fine. I am trying now to get it working with QtVlm for Real Boat Usage.

I cant find anything specifically in this forum, but I am assuming QtVlm doesnt support GPSD. If thats the case I assume Ill have to use some other info I found dating back a few years ago to create a script using
gpspipe -r | socat - PTY,link=/tmp/gpsout,raw

Then Ill use/tmp/gpsout as the serial port name in QtVlm.

It seems to work and I am still using OpenCPN in GPSD mode, which so far seems to be ok, running both at same time.

I really just want to confirm if this is the best (only) way. Merci.

[oxygen77]

yes it is the right way to do it

I've conducted some tests using gpsd with qtVlm. The code I made was running fine but we didn't add it to the official version yet as it is not working under windows.

I'll create a ticket to make the proper dev to have it available under linux

[sinbad7]

Android users and maitai...

Please note that one of the few Android based navigation programs compatible with qtVlm´s Route Optimizing format is OruxMaps (FREE) suitable for your tablet or smartphone.
See attachments.

In combination with the free AutoAppOrganizer AND ESFile Explorer,you can store all your imported .kap maps on a Cloud Drive and access/install only the maps required at a click via internet,preserving your limited RAM.

With AutoAppOrganizer,you can set up your own windows with personal, downloaded icons of your choice. Allows you to create a Backup directory
on your cloud drive of all your apps which can later be deleted from your tab/smartphone,clearing RAM,for later revival with just a click in ESFile Explorer. (ESFile Explorer have direct access to cloud based storage)

Tore

[kiwisails]

Oxygen77 - thanks, its all working fine with that BU-353 S4 model, it actually picks up a strong signal from inside which was suprising.

Just a few more questions before I use this in a Real Boat situation which I cannot find in the Wiki or forum. If I am blind then let me know please.

1. Vacation - is a term I have not come across, but I gather this is a measure of time of 5 minutes. So 1 Vacation = 5 Minutes. 12 Vacations is an Hour. A term I have not heard but makes sense. Just correct me if I misunderstand.

2. Tacks/Gybes % appears in Routes - the note says "Percentage of polar used for one vacation after tack or gybe." And I see there is also a default setting for this for real boats. I am assuming its a measure of efficiency for the first 5 mins after tack or gybe. In other words when I tack/gybe for the first 5 mins I am only running at x% or the polar value. After that on vacation #2 (or >5mins) back to polar value. Is that it?

3. Crank nb per calculation step appears just under the above in Routes. And I see in settings under Options -> Settings -> Boats P { margin-bottom: 0.08in; }A:link { }The size of the polar is either fixed or based on the reckoning length (default and best), so you need to put a value in the reckoning field. 12 or 24 vacations should do it (meaning 1h or 2h, since a vacation is 5mn). there is a reference to Reckoning Calculation with options for time, crank or distance. In this case, not what these two things are for, and if its applicable to Real Boats. I know this has something to do with the Polar under Options -> Settings -> Compass.

I found a comment that says the "The size of the polar is either fixed or based on the reckoning length (default and best), so you need to put a value in the reckoning field. 12 or 24 vacations should do it (meaning 1h or 2h, since a vacation is 5mn)."

So I think I understand hows it set up, but I am struggling with what its purpose. Any insights would be appreciated.

The rest I think I have an understanding either from the Forum or Wiki.

Thanks All.

[rgleason]

Kiwisails, That's a pretty clever way to get GPS. I think I can help with some of these items above, but I am sure Maitai or Oxygen will chime in:
1. Correct
2. You have the concept, I am not sure of exact numbers.
3. The polar is shown generally at the boat if it is turned on, and it can be shown marking where the boat will be, as you correctly state in one hour or two, user setable.

Its been awhile since I did the VLM Vendee, so I might be a little rusty, but I hope this helps. Maitai was a great teacher which I really appreciated.

Best

[kiwisails]

Rick

Thanks - I actually picked up the idea on another forum - lots of clever folk out there. I would not have thought to use a file as an input. Very smart.

Seems I am close to understanding the last settings. Just cant get my head around #3. I figure its some sort of look ahead based on Reckoning...but then alas headache sets in If I can get this figured out - I promise Ill send "The Dummies Guide to QtVlm for Real Boats" to the developer.

After getting a handle on the features Ill play with the application. Routing across a wide passage like Florida to Bahamas, a trip I am doing at the end of the year, seems close to what I would expect. I am having more trouble I notice with a routing from Annapolis to Norfolk down the Chesapeake as keep hitting coastline. But a few more POIs are probably the issue.

Anyway Ill wait till Matai gets back - cheers.

[maitai]

Hello Kiwisails and all,

1) You are right, vacation in the case of a real boat is hardcoded to 5mn. If you were using qtVlm in virtual-racing mode through VLM server, this parameter would be send by the server depending on the race settings. qtVlm is a discrete system and needs a time step for it's calculation.

2) Yes that's exactly what it is. There is a development ticket (#103) pending to increase this penalty over several vacations, but this is not done yet. BTW tickets are here: https://sourceforge.net/p/qtvlm/features-request/

3) Crank and vacation are synonyms in our poor frenchglish language The parameter under route is a way to deteriorate route calculations (if you put 12 there, instead of calculating with a step of 5mn it will calculate with a step of 1 hour). Why would you like to do such a thing? In fact I use it to compare qtVlm's calculations with other routing software that are using a longer step. I guess you'd better ignore that setting. The other parameter is something completely different. It's the way to set-up the reckoning, i.e. the esteem of the boat. This is the thin black line that starts from the boat and show where you will be after either a number of vacations, a fix amount of time, or a distance. If you show the polar on the screen (Key L), then this setting applies also for the size of the polar, since the polar has normaly the same size as the reckoning, assuming you don't change heading (and speed unless a fix distance is selected). So in short this setting does not impact routes and routages calculations, but just the way reckoning line and polar are shown on the screen.

I hope this helps, do not hesitate to ask further clarifications...

BTW 3.4.1 version is under beta testing and it should not be long before it's released. qtVlm port to Android is underway as well, although it's going to take a bit of time to adapt the user interface on such small devices...

[sinbad7]

re my # 340 post - OruxMaps and qtVlm..

Please note you have to import the Optimized Route in .kml format in order to display the data correctly.

qtVlm porting to Android is underway, although it's going to take a bit of time to adapt the user interface on such small devices...

Tore