Servers by jDrones

# Sailboat Support

(karla) #392

Yes, the cup-type anemometer for wind speed is the same I used @patmo141.
I did not need any resistors for it to work. That was needed for the wind vane though.
You can scroll up and check in this long thread.
I think the fact you do have readings is a good sign. Have you checked the factor multiplierâ€¦

(karla) #393

@patmo141 I was thinking of this calculation and setting

. for the wind speed calculation with the cups: RPM_SCALING calculation =
from RPM to Wind speed meter/sec:
Circumference = 2 x PI x Radius = 2 x 3.141 x 0.09
Anemometer drag factor = 1.18 according to their data sheet
Then divide by 60 for the RPM minute to m/seconds.
(0.5654 x 1.18) / 60 = 0.011119
RPM_SCALING = 0.011119

(Patrick Moore) #394

@karla yes I borrowed the factor you provided above. My readings donâ€™t seem like they fluctuate at all with spinning the cups though.

(karla) #395

I remember that when I got it to work it was surprising.
Please try to connect one of the wires from the cups to ground and the other wire to signal. No 5v at all involved.

(karla) #396

also, you need to spin the cup rotor for 5, 10, 15 sec before it show any speed. There is an average over time. Also you may need to have a lipo attachedâ€¦

(karla) #397

Hey!
some development here
This morning I had a chance to sail the laser with the standard rig with the new autopilot and the new wind instrument
This is a great leap for me from the first sailing, 2 years ago with librepilot.org.
ArduRover sail boat can do tacking to reach target position, and sheet out/in on heeling angle.
I am very inspired of the sailing this morning.

. Manual mode
(+) sails as expected no issues

. Acro mode
(+) keeping course when rudder stick is at neutral.
(+) sheeting in and out depending on wind was correct direction.
(+) heeling at 20 degrees was correctly sheeting out when over reaching.

. Auto mode
(+) reaching wp1 and wp2 and then wp1 again but interrupted by me with a RTL command .
(-) overshooting the target a lot (PIDs?)

. RTL mode
(+) getting there
(-) over shooting a lot in tacking. How to fix?

Please have a look at the video below.
Please understand that the mag was calibrated elsewhere and should have been done at site.
so please turn sound down or limit it since it will complain about
. Error Pos Vert variance
. Error Compass Variance

However, it seems the baro has no impact and the compass is still correct.

The video is over 10 min and it is going from
.Manual
.Acro
.Auto
.RTL
.Manual

I need more sailing trips to understand what needs to be tuned.

Thanks a lot!
K.

(Peter Hall) #398

The FPV is very cool!. The compass is defiantly quite un-happy, fixing that will probably help quite a bit. On the RTL you can see its heading is nearly 90 deg off from the direction it is moving in. Maybe you can move it way from metal or the servos. my boat has the same issue, although not quite so bad, hard to get any separation when the water proof compartment is so small. Quite tricky to tune up the steering PIDâ€™s as its hard to go at a consistent speed, iâ€™m still on the defaults and it is not too bad.

(karla) #399

Haha, yes and helpful looking at after the sail to understand what happened.

This morning was time for the maiden sail with the Wing Sail rig.

I started with a new compass calibration at the site.
After that there was no complain of compass variance or any other complains. So I think the location of the mag on deck close to the mast is okay. No servos around but some other stuff, however I can move it around on deck as needed. At the moment it seems totally fine though

The wind this morning is weak, shifting direction, and gusty.
Not ideal at all, but I am eager to get some first try of the wing.

1. I have no prior experience and need to figure out how to sail with a Wing and control tab from ground up.

2. I had to place the boat too far away from where I was standing to get some free wind.

3. Sailing in weak wind means the wing donâ€™t move despite control tab changes.

4. My impression is that the wing can sail the boat well in good wind - has potential,
I just donâ€™t know how to operate it yet.

5. After some 14 min of trying to sheet in and out and get some boat speed, I lost patience and turned on the Motor and headed home Good to have a motor!

6. I had the idea that if there is no wind and starting a motor with the control tab at neutral, i assumed the rig would turn to straight forward - I think it did.

2 Likes
(Peter Hall) #400

looks good!, i know the theory but have also never used a wing sail. It seems to be work OK, as you say more wind will help, I will have to pull my finger out and get the code done.

(David Boulanger) #401

You hit 1 knot every now and then. Thatâ€™s not to shabby for a test.

Edit: More than 1 knot

(Patrick Moore) #402

ok great, looking forward to testing with LiPi + Ground/Signal connection + continuous spinning. If that doesnâ€™t work Iâ€™ll order a box o resistors Thank you for the suggestions!

-P

(karla) #403

@David_Boulanger, yeah i guess you right not too shabby for a maiden. I can use the standard rig in light winds and the wing when more brisk. It should be basically the same to sail them, getting a good desired angle to the wind, only difference is the sheeting is indirect via the control tab, but the goal is the same.

A question regarding waypoint missions.
The wiki mentions WP_OVERSHOOT but I canâ€™t find the SAIL_MAX_XTRACK parameter in the MP version I have? @iampete

B t w I could try out your motor setup code you completedâ€¦ no hurry though

(Peter Hall) #404

WP_OVERSHOOT defines the maximum cross track error before tacking in master and stable. I had SAIL_MAX_XTRACK on my dev build for abit.

The good news is that SAIL_MAX_XTRACK is coming back with the motoring stuff since you it can turn off all the sailing stuff so need the WP_OVERSHOOT for its original use. Iâ€™m working on the wiki for the motoring stuff today, I will do you a firmware build and hopefully the updated wiki will explain everything ok.

1 Like
(Peter Hall) #405

This is the motoring build for KakuteF7 : https://drive.google.com/open?id=1VkG3ZbFLv7WuwFO12Qk7xotpgGdPVeib

No instructions yet tho, thatâ€™s tomorrows job

1 Like
(karla) #406

Just a general question, when loading a new version of the code must all calibration of accelerometers and compass be redone or will the â€˜oldâ€™ settings be working if just loading up the settings file from the previous version?

(Peter Hall) #407

old calibration settings will be fine in most cases, it will fail pre-arm if it needs redoing. In most caseâ€™s everything upgrading will be fine, although as your going from old master to new master rather than between stable releases there could be some funny stuff.

The thing to be careful of is flashing parameters from file, in general it is a bad idea to flash all parameters from from a file, better to compare and only change the ones that you understand.

1 Like
(karla) #408

Just come to think about it, did you try to swop the wires?
I remember only one way worked, but canâ€™t remember which way.

(Peter Hall) #409

@patmo141 @IAMMATT 's excellent new RPM wiki page just went live, possibly it can shed some more light on the setup.

http://ardupilot.org/rover/docs/common-rpm.html

1 Like
(jason odell) #410

Hello, new guy here I created an account to make you aware of this project if you werenâ€™t already. https://blog.sotonsailrobot.org/
They use small magnets in a wind vane to over drive a magnetometer and get wind direction. Very low friction if you balance it well. Anyway seemed relevant as the ultrasonic stuff is pretty expensive.

(Peter Hall) #411

HI Jason, welcome,

Iâ€™m aware of the lads down at Southampton, its a neat idea, we do already support loads of compasses, it maybe quite easy to add it as a driver back-end. I think the tricky bit is to try and stop the code useing it for navigation, there is lots of code to failsafe between compasses ect. Would probably need a new calibration method too.