Route Planning with GRIB - Work in Progress

[sinbad7]

maitai..

What do you know.. I even manage to import the optimized route to my Galaxy S II smartphone.

Tore

[maitai]

Better simplify it before to get less points, though (and export only POIs also)

[sailinman]

im having trouble creating a route?!?! it says no polar ... hmmm.... what did I miss?

[sinbad7]

maitai..

1. How do you avoid creating optimized course over land?
2. How do you reduce the number of waypoints?
Using ´simplify´method and onlu export the POI´s ?

sailinman...

You have to select a boat type and it´s polar rating before you can create a route.
Boat/Boat setting and select polar.

Tore

[maitai]

1) If you created the route manually then you have to set the critical points as "not-simplifiable"

If the route was created via a routing this is done automatically if the point is close to land.

2) yes

[Zoef]

Maitai,

It took me some time to get the hang of it but finally managed to make routes in qtVlm. Now it's simple comme bonjour, with one exception.
I sail mainly in the Med, where the wind blows with either 5 or 50 knots, and the reality is that I use the engine quite often to go with at least 5 knots. Is there any way to make qtVlm automatically redo the calculations for these parts of the route where the calculated boat speed (based on polar & grib) drops below e.g. 4 knots and assume that the engine drives the boat with e.g. 5 knots in the target direction?

[maitai]

Yes, you can specify exactly this in the boat's settings (if my boat speed with sails is less than x knots, then I use the engine and travel at y knots). Since this information is a the boat level and not at the route/routage level (it was easier to do), if you change it it will affect also existing routes. If you want to avoid this you have eventually to freeze existing routes before. Same thing with polar's efficiency.

Note: the use of engine with routage does not imply you will go straight to the destination. The routing module always tries to optimize ETA, so maybe using the engine to reach an area with more winds is better than just going straight.

[Zoef]

Maitai,
Thank you for the instructions. I should have studied all the options more carefully.
In the route details (via Routes-edit route) I can see the time the engine will be running, and thus the expected fuel consumption. Very useful program.

[sinbad7]

Very interesting playing around with qtVlm.

I have set the boat configuration to use engine with speeds under 4 kn,and an engine speed of 8 kn.

Having created the grib route and exported it as a .gpx,the speed only shows up as an average 7.5 kn? I would have expected a varying speed to be shown? Perhaps I am missing something?

Tore

[maitai]

What does it say in the route's log from qtVlm? (route->edit>2nd tab)

[Zoef]

Originally Posted by sinbad7

Very interesting playing around with qtVlm.

I have set the boat configuration to use engine with speeds under 4 kn,and an engine speed of 8 kn.

Having created the grib route and exported it as a .gpx,the speed only shows up as an average 7.5 kn? I would have expected a varying speed to be shown? Perhaps I am missing something?

Tore

Hi Tore,

Isn't this an OpenCPN issue? In its "Route Properties" box you can only specify 1 plan speed.

Klaas

[sinbad7]

Klaas..

Yes you are right,but if I could have imported it as a Track,the times would probably be there?

Tore

[Zoef]

You are ahead of me Tore, I did not export anything from QtVml. But I think it's a great idea to import the route as a track in order to conserve the varying calculated speeds.

[sinbad7]

maitai..

The route´s log file in qtVlm is EXCELLENT showing all data required,but it does not export it all,or if it does,in a format not acceptable to OpenCPN.
Normally OpenCPN only displays actual date/time in Track modus..

Could you provide a Track data export/import option as well?

Tore

[sinbad7]

maitai

How can I start qtVml in the configured version with the present boat and grib details from a path?

Using this path only loads the original/virgin version of qtVml without any data:
file://C:/INSTALLED PROGRAMS/TRIP PLANNING/qtVml.exe

Finally,can I start qtVml straight from the log Route-Edit-Route Details page?
This would be very useful,as I can set up a POI in OpenCPN taking me direct to this page in order to display ALL details quickly.

Tore