Jun 13, 2012, 03:45 PM
Registered User
South Africa, GP, Johannesburg
Joined Sep 2010
2,495 Posts
Magnetic Declination

I have been doing an exercise to check the correct declination to be used, which is not complete yet, by placing my hexa on a solid surface and leaving in one position and changing the declination and then measuring the Longitude and Latitude, over a period of about 3-4 minutes. There were 9 Satellites and the DOP as determined by Trimble online was about 0.8.

My declination is -18 so I started with +19 and then worked my way down. There are a few gaps. I then took the co-ordinates and worked out the distance between the two extreme points. This in theory should be the amount that the multirotor will move.
Dec..Movement
+19..6.31m
+18..10.05m
+17..12.59m
+16..3.45m
+15..3.19m
+14..7.46m
+13..9.84m
-12..6.38m
-14..8.33m
-18..8.33m

I am going to rerun the exercise again tomorrow and also fill in a few gaps, but it looks like that even though I should be using a declination of 18, in fact I should be using +15 as this gives a less movement.

Just for interest, I attach a map showing how dense the contours are over Southern Africa, and a few other areas in the world, such as Chile and Northern Canada, which makes it even more necessary maybe to run the exercise I have just done to get the correct declination to use. In other parts of the world, it looks like it is not so necessary to be as accurate.

Rob

# Images

Jun 13, 2012, 03:54 PM
Why didn't they run? A pass???
United States, WA, Woodinville
Joined Mar 2007
8,412 Posts
Quote:
 Originally Posted by robone I have been doing an exercise to check the correct declination to be used, which is not complete yet, by placing my hexa on a solid surface and leaving in one position and changing the declination and then measuring the Longitude and Latitude, over a period of about 3-4 minutes. There were 9 Satellites and the DOP as determined by Trimble online was about 0.8. My declination is -18 so I started with +19 and then worked my way down. There are a few gaps. I then took the co-ordinates and worked out the distance between the two extreme points. This in theory should be the amount that the multirotor will move. Dec..Movement +19..6.31m +18..10.05m +17..12.59m +16..3.45m +15..3.19m +14..7.46m +13..9.84m -12..6.38m -14..8.33m -18..8.33m I am going to rerun the exercise again tomorrow and also fill in a few gaps, but it looks like that even though I should be using a declination of 18, in fact I should be using +15 as this gives a less movement. Just for interest, I attach a map showing how dense the contours are over Southern Africa, and a few other areas in the world, such as Chile and Northern Canada, which makes it even more necessary maybe to run the exercise I have just done to get the correct declination to use. In other parts of the world, it looks like it is not so necessary to be as accurate. Rob
very interesting.

I'm using -16 since I am at +16 (WA state)
Given the wide gaps between the dec lines, it would seem that my locale is about as accurate as its going to get with regards to actual dec settings.
 Jun 14, 2012, 11:35 AM Registered User South Africa, GP, Johannesburg Joined Sep 2010 2,495 Posts Did another exercise today just to check the readings yesterday and had the following results: Remember, my declination should be +18 +20...12.8m +19...8.8m +18...7.8m +17...7.8m +16...6.3m +15...3.8m +14...3.7m +13...6m +12...5m +11...4.8m +10...4.4m +9...6.8m So this correlates with my readings yesterday showing that +15 should be about the right declination to use, instead of the +18. Just some background from http://earthsci.org/education/fieldsk/declin.htm : "Local anomalies originating in the upper mantle, crust, or surface, distort the WMM or IGRF predictions. Ferromagnetic ore deposits; geological features, particularly of volcanic origin, such as faults and lava beds; topographical features such as ridges, trenches, seamounts, and mountains; ground that has been hit by lightning and possibly harboring fulgurites; cultural features such as power lines, pipes, rails and buildings; personal items such as crampons, ice axe, stove, steel watch, hematite ring or even your belt buckle, frequently induce an error of three to four degrees." I am going to run some further checks over the next few days, and only when there are 9 or more satellites. One thing I did notice is that as soon as the number of satellites drops down to 7/8, the level of accuracy vanishes completely and the multirotor starts to wonder all over the place. This correlates with my experience. As soon as I got 7 satellites I took off which is something I wont do again. I then checked the DOP on http://www.trimble.com/GNSSPlanningOnline/#/Settings and one can see straight away the DOP increases, but not always. It is worth using this as a planning tool to decide when you are going to fly and use. Just for interest, I get 10 satellites for 1 hour, 9 for about 3 hours and the rest of the day is a mix of 7-8 satellites. I checked other locations around the world and most of them fare better with the number of satellites. Got my Android Tablet and my Hexa is re-built after the last crash. So, now I must just work out how to use the Android as it is different to the iPhone I have been used to.
 Jun 14, 2012, 03:47 PM Registered User Finland, Uusimaa, HKI Joined Jan 2012 314 Posts Regarding to post tracking at last it looks like i'm getting my YS parcel tomorrow, and i think i'll straight replace WKM with YS in my CineStar 6 frame so i can possibly do one shooting with YS as soon as next wednesday. I have been playing around with PC GCS, but few questions are in my head about configuring it up. If you please can help me with these, i'd be much more than happy: 1. Has anyone tried with CC phoenix esc:s with latest mr fw, are they performing good or should i put SimonK flashed which i remember someone here had succeed well. ESC type normal right? 2. I'm going to use Futaba T8FG with s-bus, is there any tweaks i should know? I guess it's best use aircraft mode, throttle reversed and all others normal or how you have set them? Can i see somewhere the directions are right and not reversed? 3. How do i set up tx channels in YS pc GCS? Is there somewhere indicators that show current functions, positions and travels? 4. How to setup failsafe with futaba s-bus? 5. What parameters i should adjust and which direction for first flight with hexa auw 5kg? - roll and pitch sensitivity are regular gains right? - what does Roll and Pitch I ? - what does Throttle P and I and Ctrl type? - what does Rotate P and I and vertical stable? - Broken Rod? - aircraft type? - Steering gear frequency? 6. How do i input my setup mixing to controller (I6)? 7. Do i need to put imu and gps (XYZ) location from CG somewhere? I know there is a lot to ask and will be even more when i'll have the unit here at my desk, but these would help me a lot at this state, thanks in advance for your help. Kari
 Jun 15, 2012, 07:22 AM Registered User Joined Dec 2010 501 Posts Any info on the YS-X6 joystick? Price and availability.
Jun 15, 2012, 08:45 AM
Registered User
Joined Feb 2010
206 Posts
Finally starting to get a handle on the Jello issue I've been having. Check out my latest video:
 YS-X6 on a DJI F550 Frame +GoPro in R3 (4 min 56 sec)

I don't have the servos on the gimbal hooked up yet. It's a long story, but I basically need an 8ch receiver to be able to use it (I only have 7).

I'm still playing around with the gimbal setup, but it's starting to look much better, agreed?
Jun 15, 2012, 08:50 AM
Suspended Account
Joined Nov 2011
597 Posts
Quote:
 Originally Posted by redridinghood Any info on the YS-X6 joystick? Price and availability.
http://www.multirotortech.com.au/shop look at the top kit, comes with everything.
Jun 15, 2012, 09:21 AM
Registered User
South Africa, GP, Johannesburg
Joined Sep 2010
2,495 Posts
I have sent off my Flight Data file to ZeroUAV for them to have a look at.

Went out to a new location today, and starting with a declination of 15 up to 18, then checked each for co-ordination movement while still on the ground and 18 seemed to provide the minimum movement. I then took off using 15 and then later changed to 18 and as soon as I switched to GPS mode, the hexa flew all over the place. Tried a few times, and as soon as I switch on GPS it wants to go to some other country.

Went home, recharged the batteries and went back to same location. Re-calibrated the compass, twice, and then flew again. Left the declination now at 18 and as soon as I switched on the GPS it took off to some other location. Only way to control it was switch to Manual Mode 1 and fly back.

In manual mode 1 it is the best flight controller around. I think I may have a dud GPS, as what I get is not funny. I have used 2 other flight controllers with GPS's. Both had problems, but the multirotor always stuck around in within about 10m of the intended location

Anyway, attached is a pic of my setup.

Rob

Edit: In all cases, I had more than 9 satellites
My switch settings are correctly set. Checked on the Android.

# Images

Last edited by robone; Jun 15, 2012 at 09:26 AM.
Jun 15, 2012, 09:05 PM
Why didn't they run? A pass???
United States, WA, Woodinville
Joined Mar 2007
8,412 Posts
Quote:
 Originally Posted by Reginak For AV200 these number are too high...

not for me..at least not roll

I have ptz roll = -49 and it holds a fairly steady horizon
I have ptx pitch = -19 and it sucks. I'm trying little incriments at a time, but below -19 its too slow, and above it, it seems it moves too much.
 Jun 15, 2012, 09:07 PM Why didn't they run? A pass??? United States, WA, Woodinville Joined Mar 2007 8,412 Posts on another note, anyone fly an Octo with a heavy load yet? I've got a random twitch when loaded down. Happens every once in a while. Maybe twice in a 6 to 7 minute flight. like one of the left rear motors provides more thrust, then the FC immediately compensates. V, does ZeroUAV ever request flight data logs to evaluate what we are seeing in the field with the various different configurations?
 Jun 15, 2012, 10:34 PM http://gothelirc.com/ United States, AZ, Chandler Joined Dec 2011 1,113 Posts If you're experience a problem in flight, please email and let me know full detail and the flight log. I will forward it to them to so they can look at it.
 Jun 15, 2012, 10:53 PM DJI Support Las Vegas/Lake Tahoe Joined Feb 2010 16,383 Posts \$4000 for the Pro Kit!!! That is a lot of money. Latest blog entry: How to reload P3 firmware
Jun 15, 2012, 11:34 PM
Suspended Account
Joined Nov 2011
597 Posts
Quote:
 Originally Posted by Tahoe Ed \$4000 for the Pro Kit!!! That is a lot of money.
Not when you compare the features with the equivalent to the WJM with waypoints and GCS it isn't.
 Jun 15, 2012, 11:42 PM DJI Support Las Vegas/Lake Tahoe Joined Feb 2010 16,383 Posts DJI WKM, 900 mHz Data Link and Waypoints \$3340. I guess \$660 isn't that much less the cost of a joystick. Latest blog entry: How to reload P3 firmware
Jun 16, 2012, 12:02 AM
Suspended Account
Joined Nov 2011
597 Posts
Quote:
 Originally Posted by Tahoe Ed DJI WKM, 900 mHz Data Link and Waypoints \$3340. I guess \$660 isn't that much less the cost of a joystick.
It's beyond my budget, but from what I've seen, Ed, the YS goes great down under here, and of you are flying a CS8 or S800 the extra is an 'insurance' premium perhaps? I'm certainly not knocking DJI, but friends wh have both seen overly excited about the YS. Each to their own I believe. Im still getting my ship set up, so haven't even started on waypoints etc yet.