Airplane mode RTH

denism · Post by **denism** » Fri Feb 21, 2014 7:28 am

Is there a benefit of having BARO and COMPASS in addition to the GPS?
GPS provides ASL altitude and heading is calculated. With multirotors there was definitely benefit from compass, but this is always moving airplane now.
Any advise on using / not using BARO+MAG? Those two little guys on the right. I build around board with MPU6050 only, so BARO and MAG can be external. With MAG it anyways best option to move it away from motor wires.

Thanks!

PatrikE · Post by **PatrikE** » Fri Feb 21, 2014 3:07 pm

Keep it simple.
It will fly fine with MPU + Gps.
No need for Mag and Baro for Fixed wing.

It seems you are using I2CGps.
Use the Modified I2CGps code included in the dev file.

I also have a modified version of KV osd that shows
Mag and Baro related data based on GPS.

denism · Post by **denism** » Fri Feb 21, 2014 3:31 pm

Thanks Patrik, I loaded I2C code you included with your FW.
Can you please post the link to the modified KV OSD?

Good to hear that I can skip on BARO and MAG, sketch barely fits in to the 28k on 32u4 already.

PatrikE wrote:Keep it simple.
It will fly fine with MPU + Gps.
No need for Mag and Baro for Fixed wing.

It seems you are using I2CGps.
Use the Modified I2CGps code included in the dev file.

I also have a modified version of KV osd that shows
Mag and Baro related data based on GPS.

PatrikE · Post by **PatrikE** » Fri Feb 21, 2014 6:21 pm

I Packed all All tools and Modified Versions I Used For Dev.
Info in the Package.
FixedWingNav.rar
All major problems is fixed and It feels Stable now.

/Patrik

denism · Post by **denism** » Fri Feb 21, 2014 9:17 pm

Thanks for the set.
You do not maintain source code in the http://code.google.com/p/multiwii/sourc ... ingNav_Dev , just archives?
PITA running diffs to see what is changed between releases.

PatrikE wrote:I Packed all All tools and Modified Versions I Used For Dev.
Info in the Package.
FixedWingNav.rar
All major problems is fixed and It feels Stable now.

/Patrik

PatrikE · Post by **PatrikE** » Fri Feb 21, 2014 9:47 pm

https://code.google.com/p/multiwii/source/browse/#svn%2Fbranches%2FPatrikE%2FFixedWingNav_Dev%2FMultiWii
No Actual changes since last rel just some cleanup and
Merged with latest code from MultiWii_shared.

denism · Post by **denism** » Sat Feb 22, 2014 8:21 am

That is perfect.
FYI I fly multiwii acc/gyro modes oh the fixed wings for over a year now (F-35, Twinstar, X-8 FPV) and now I think I will test NAV code on ModelAero Polaris Ultra.
You have some PIDs/ GAINs established. What kind of the plane those are tailored to? That is in regards of aileron/rudder/elevator authority and level flight throttle. Just want to get adjusted it as close as possible to the airframe I will be flying with.

PatrikE wrote:https://code.google.com/p/multiwii/source/browse/#svn%2Fbranches%2FPatrikE%2FFixedWingNav_Dev%2FMultiWii
No Actual changes since last rel just some cleanup and
Merged with latest code from MultiWii_shared.

PatrikE · Post by **PatrikE** » Sat Feb 22, 2014 11:57 am

Clear Eeprom or reset from Gui.
Default PID's For FW will be loaded after that.

I have used a Easystar clone.( Dynam EZ-Hawk )
And Hobbyking RadJet 800 during testing.
I have used same settings for both models.
Radjet may need a little higher P for Altitude.

I have actually never flown it with a model with rudder.
Only Ailerion/Elevator.

denism · Post by **denism** » Sun Feb 23, 2014 1:02 am

all with rudder. On x-8 wing I use split ailerons with custom mixing for the rudder. Lower yaw P to about 3.0 on all.

Code is missing yaw expo. Need to have that separate from ail/ele expo.

moti0072 · Post by **moti0072** » Sun Feb 23, 2014 9:53 am

PatrikE wrote:New update witch should work on Mega boards
[url?https://multiwii.googlecode.com/svn/branches/PatrikE/FixedWingNav_Dev/FW_Nav_140214.rar]FW_Nav_140214.rar[/url]

Servo order is.
Wing1 D7 & D37
Wing2 D6
Rudd D2
Eleva D5
ESC D3

Hi PatrikE
I update my card with this fw after i arm and setup the sw its arm but not move any servo ...i need to do any more?

PatrikE · Post by **PatrikE** » Sun Feb 23, 2014 11:47 am

In config.h
Try to Comment
#define MEGA_HW_PWM_SERVOS

PatrikE · Post by **PatrikE** » Mon Feb 24, 2014 12:26 pm

Bench Tested servo outputs on a Crius AIO
Using MEGA_HW_PWM_SERVOS

SERVO4 = pin 11 (aileron left for fixed wing or TRI YAW SERVO)
SERVO5 = pin 12 (aileron right for fixed wing)
SERVO6 = pin 6 (rudder for fixed wing)
SERVO7 = pin 7 (elevator for fixed wing)
SERVO8 = pin 8 (motor for fixed wing)

Without MEGA_HW_PWM_SERVOS

SERVO4 = pin 7 (aileron left for fixed wing or TRI YAW SERVO) +D37
SERVO5 = pin 6 (aileron right for fixed wing)
SERVO6 = pin 2 (rudder for fixed wing)
SERVO7 = pin 5 (elevator for fixed wing)
SERVO8 = pin 3 (motor for fixed wing)

moti0072 wrote:I update my card with this fw after i arm and setup the sw its arm but not move any servo ...i need to do any more?

USB will not drive the servos!
External Power must be connected! (ESC or BEC)

moti0072 · Post by **moti0072** » Mon Feb 24, 2014 12:42 pm

I test with esc ,
I connect the esc to board and the servo just signal ...

moti0072 · Post by **moti0072** » Mon Feb 24, 2014 12:57 pm

I select arm in the switch my be arm with the stick

denism · Post by **denism** » Mon Feb 24, 2014 3:54 pm

What about true airspeed? GPS speed is good .... for multirotors. And with wind it becomes dangerously wrong speed indicator for airplanes.
Have spare MPXV7002DP. Can Mutiwii NAV support it?

PatrikE · Post by **PatrikE** » Mon Feb 24, 2014 5:39 pm

There's a. Thread about it in the forum.
It will be hard to fit in smaller processors.
I don't have any sensor to experiment with
but it would be a good complement to the project.

PatrikE · Post by **PatrikE** » Tue Feb 25, 2014 1:44 pm

The Airspeed thread.
viewtopic.php?f=8&t=2450

denism · Post by **denism** » Tue Feb 25, 2014 4:54 pm

Yes thanks, found KaiK work and dropped that code in.
Now I think of ignoring GPS speed and replacing it with true airspeed reading. When airspeed reading is no longer updating switch back to GPS speed. Keep GPS speed as a backup.
There are airplanes which drop the wing , not the nose in the stall

PatrikE wrote:The Airspeed thread.
viewtopic.php?f=8&t=2450

PatrikE · Post by **PatrikE** » Tue Feb 25, 2014 10:32 pm

Using ground speed can be really wrong with Head/Tailwind.
Current Code only use GPS speed to ensure the plane moves toward Home with a minimum 400cm/s (~12 km/h)

It should be possible to Change to TrueAirspeed instead of GPS speed.
But there should still be a check to make sure Plane is moving forward in strong Headwind.

denism · Post by **denism** » Tue Feb 25, 2014 11:12 pm

I plan to have GPS speed displayed with modified KV OSD as well as TrueAirspeed. And make Nav code use TrueAirspeed, calibrated.

PatrikE wrote:Using ground speed can be really wrong with Head/Tailwind.
Current Code only use GPS speed to ensure the plane moves toward Home with a minimum 400cm/s (~12 km/h)

It should be possible to Change to TrueAirspeed instead of GPS speed.
But there should still be a check to make sure Plane is moving forward in strong Headwind.

msev · Post by **msev** » Fri Feb 28, 2014 11:45 am

Soooo when will Alex integrate this into shared ;-)

...seems its stable, many positive user comments

PatrikE · Post by **PatrikE** » Fri Feb 28, 2014 12:50 pm

I think It's ready to merge in to shared branch now.
I have found some issues with Failsafe if Gps fails while Passthru.
But It's same issue on normal V2.3
I will fix that first!
After that it's up to Alex if it's ok to GO.

The big issue is if I2C_GPS is used.
that it requires the modified I2C_GPS.
OSD Data from original I2C_GPS gives wrong OSD data witch FixedWing use for navigation.
If you use wrong I2C_GPS the plane will not navigate correct!

For Serial GPS there's no such problems.

fryefryefrye · Post by **fryefryefrye** » Sat Mar 01, 2014 12:31 pm

PatrikE wrote:I Packed all All tools and Modified Versions I Used For Dev.
Info in the Package.
FixedWingNav.rar
All major problems is fixed and It feels Stable now.

/Patrik

I want use this code to my plane. But there is a problem. So I switch back to Official 2.2 for my first fly.

Rudder is working OK in pass-through, But it will turn to one director slowly in other Mode. PWM from 1500 goto 1700 in about 10sec.

If the control stick of rudder moved and stop, the rudder will goto center and then move to 1700 in about 10sec.

All input values from gyro when the problem happen was 0.

PatrikE · Post by **PatrikE** » Sat Mar 01, 2014 2:46 pm

Set Yaw I to zero.

fryefryefrye · Post by **fryefryefrye** » Sun Mar 02, 2014 2:03 pm

PatrikE wrote:Set Yaw I to zero.

It's worked. Thank you.

I'm flying the MWC 2.2 on airplane with ANGLE mode today, It's so easy to fly.

I try to switch to GPSHome with MWC 2.2, the plane keep flying higher and higher, but it will turning around above my head, and will not goto far away. Any ideas about that ?

I will try your GPS function next time.

Do you know the BARO is working for airplane ? I want to use the Alt keep function for airplane.

PatrikE · Post by **PatrikE** » Sun Mar 02, 2014 2:59 pm

MWC 2.2 does NOT support RTH with Planes!
It will behave exactly as you describe.
You need to use FixedWingNav version for planes.

Is there other problems than I-Term when you use FixedWingNav ?

Do you know the BARO is working for airplane ?

Not in current version.
It will only control throttle but not Elevator.

fryefryefrye · Post by **fryefryefrye** » Mon Mar 03, 2014 2:44 am

PatrikE wrote:
Is there other problems than I-Term when you use FixedWingNav ?

Sunday is over when I got your reply about "I-Term". So I'm fly with MWC2.2 on Sunday.

I have updated FixedWingNav in my plane and finish the ground test.

I will try GPSHOME next time.

Is the GPS_hold working in your FixedWingNav ? If it will work, what about the Altitude will work?

PatrikE · Post by **PatrikE** » Mon Mar 03, 2014 9:51 am

GPS_hold works.
It will save the pos in 3D where it's enabled and repetedly return to the same point.
Altitude from GPS is used.
Should keep around +/- 2m.

fryefryefrye · Post by **fryefryefrye** » Mon Mar 03, 2014 1:36 pm

PatrikE wrote:GPS_hold works.
It will save the pos in 3D where it's enabled and repetedly return to the same point.
Altitude from GPS is used.
Should keep around +/- 2m.

Thank you, hope I can have the fly in the weekend of the next week.

denism · Post by **denism** » Tue Mar 04, 2014 8:21 am

Patrick,

I got that MPXV7002DP airspeed sensor working on analog input pin and reporting airspeed in the regular cm/s. Stored in gobal int airspeedSpeed.
Here is what I think I will be doing with NAV_Thro. All the rest of NAV code uses GPS_speed the way you programmed it.
Any thoughts? Is it going to break anything? Thanks!

Code: Select all

/*############### New FUNCTION ###############*/
// Force the Plane moving forward in headwind
#define AIR_MAXSPEED  3000  // Vne, ~108km/h. Airframe dependant.
#define AIR_NAVSPEED  1500  // Desired air speed in NAV mode ~54km/h
#define GPS_MINSPEED  500  // 500= ~18km/h
#define I_TERM        0.1f
int spDiff = 0;
int spAdd  = 0;

if (GPS_speed < GPS_MINSPEED) { // check for too slow ground speed
      spAdd += (GPS_MINSPEED - GPS_speed)*I_TERM;  // increase nav air speed 
} else {
      spAdd -= spAdd*I_TERM;                       // decrease nav air speed 
}  
spAdd = constrain(spAdd, 0, AIR_MAXSPEED - AIR_NAVSPEED - 100);

if (airspeedSpeed < AIR_NAVSPEED - 100 + spAdd || airspeedSpeed > AIR_NAVSPEED + 100 + spAdd) {  // maintain air speed between NAVSPEED and MAXSPEED
   spDiff = (AIR_NAVSPEED + spAdd - airspeedSpeed)*I_TERM;
   SpeedBoost += spDiff;
}
    
SpeedBoost = constrain(SpeedBoost,0,500);
NAV_Thro += SpeedBoost;
/*############################################*/

PatrikE wrote:Using ground speed can be really wrong with Head/Tailwind.
Current Code only use GPS speed to ensure the plane moves toward Home with a minimum 400cm/s (~12 km/h)

It should be possible to Change to TrueAirspeed instead of GPS speed.
But there should still be a check to make sure Plane is moving forward in strong Headwind.

fryefryefrye · Post by **fryefryefrye** » Wed Mar 05, 2014 6:48 am

PatrikE wrote:
Do you know the BARO is working for airplane ?
Not in current version.
It will only control throttle but not Elevator.

Do you have plan to write some code on Alt_Keep?
I think the code is already in your FW_NAV code, just move some of then into BARO.

For people without Baro, the GPS alt also can be used. But it will need more code to add a flight mode, I think.

Rangarid · Post by **Rangarid** » Wed Mar 05, 2014 8:15 am

Hi,

just found this yesterday, so i did not have the chance to go through this thread. I want to build a really small autopilot for one of my flying wings. Therefor i wanted the smallest possible controller. This one for example looks really nice:

But it does not have a baro. Do i need a baro for altitude or does the AP uses GPS altitude anyways? I guess the mag is not really needed, right?

PatrikE · Post by **PatrikE** » Wed Mar 05, 2014 9:37 am

Looks really nice!.
You don't need a Baro for Airplane.
Altitude from GPS is used.

MPU6050 + GPS is enough.

Rangarid · Post by **Rangarid** » Wed Mar 05, 2014 9:49 am

PatrikE wrote:Looks really nice!.
You don't need a Baro for Airplane.
Altitude from GPS is used.

MPU6050 + GPS is enough.

Thanks mate. BTW this is nanowii from hobbyking if you dont know it already.

shikra · Post by **shikra** » Wed Mar 05, 2014 10:32 am

Hi Patrick, I have yet to use it in a plane but have tested RTH for a copter from a couple of km and I'm glad to say it worked fine,

I noticed on the OSD a long time ago that the distance and speed were wrong, but only ever saw one other post about the speed
I have some code which fixes both the OSD speed and Distance added into my version of KVOSD. I took the distance out because needed the memory and I never seen anyone mention the issue. I guess not many go more than 650m on a copter!

I think I still have it - means do not have to upgrade the I2CGPS!

I can look to optimise the code and find space to add it back in... if it helps.

PatrikE wrote:The big issue is if I2C_GPS is used.
that it requires the modified I2C_GPS.
OSD Data from original I2C_GPS gives wrong OSD data witch FixedWing use for navigation.
If you use wrong I2C_GPS the plane will not navigate correct!

For Serial GPS there's no such problems.

felixrising · Post by **felixrising** » Wed Mar 05, 2014 11:08 am

On topic but not arduino... Abusemark (timecop) has a very nice small FC called the AfroMini 32.. Similar price to the nanowii but much nicer from a formfactor + baro (yeah, not used, I know

) and lots of room (cpu, ram, flash) for features.. I've just stuck a acro naze32 on a flying wing which works great, baseflight supports aircraft but obviously hasn't got PatrikE contributions ported (yet)...

Rangarid wrote:
PatrikE wrote:Looks really nice!.
You don't need a Baro for Airplane.
Altitude from GPS is used.

MPU6050 + GPS is enough.

Thanks mate. BTW this is nanowii from hobbyking if you dont know it already.

crashlander · Post by **crashlander** » Wed Mar 05, 2014 12:02 pm

I'm also in process of sticking AfroMini32 on my FW.
On a plus side that board has 2 serial ports!
So lets hope the Patrik's code gets into mainline MWII and TC ports it to Baseflight (soon).

Regards
Andrej

PatrikE · Post by **PatrikE** » Wed Mar 05, 2014 2:11 pm

I Want a Afro32!....
To Bad it's sold out!..

Perfect fit in a narrow airframe.
I use a Mongoose-9DoF in my plane But the 328 is on the absolute limit of memory.
Besides it needs some soldering on the processor because PPM isn't pinnedout.
And a Mega gets too large in my plane.

Rangarid · Post by **Rangarid** » Wed Mar 05, 2014 2:15 pm

Hehe, i want one as well. Its only 18€...Hope they will be in stock again soon.

crashlander · Post by **crashlander** » Wed Mar 05, 2014 5:00 pm

PatrikE wrote:I Want a Afro32!....

Yep it is the sexy-est FC I have ever seen.
The bottom TX RX pads are probably not 5V tolerant (from checking the CPU data sheet and TC's code) but since most of UBLOX GPS's have internal Vreg and operate on 3.3V that is not problematic (at least mine gives 3.3V TX and RX when connected to 5V VCC).

Regards
Andrej

felixrising · Post by **felixrising** » Wed Mar 05, 2014 10:58 pm

Hi, yeaht/c needs to get cooking.. he knows there are a few people wanting them but is busy with other paid work and cooking up normal naze32.. but don't let that stop you from hassling him in #multiwii channel.

I think those bottom pads are 5v tolerant ... they are normally used for pin 4/5 RC input and gps on the full naze... which I have no issues using with UBLOX GPS etc..

aydineser · Post by **aydineser** » Thu Mar 06, 2014 11:06 am

How about this board
http://witespyquad.gostorego.com/the-flip32-249.html

msev · Post by **msev** » Thu Mar 06, 2014 12:42 pm

Acronaze32 from Timecop would make a similairly good platform like the afromini.. Its small at 36*36mm, cheap as its same price as afromini.. And its in stock: http://abusemark.com/store/index.php?ma ... ucts_id=38

Plüschi · Post by **Plüschi** » Thu Mar 06, 2014 2:03 pm

Flip32 has some serious problems. Esc pins wired wrong, non functional dsm port.

Afromini is really small + light + comes with baro. No onboard usb port.

e_lm_70 · Post by **e_lm_70** » Thu Mar 06, 2014 4:21 pm

aydineser wrote:How about this board
http://witespyquad.gostorego.com/the-flip32-249.html

Since TimeCop does make board which he open the HW, we can't really call this board a clone.

In the open software and open hardware the "clone" factor is part of the game

Personally I would have made a better link to the HW creator of the board, with a link from witespyquad to www.abusemark.com ... for clearly state the paternity of the board.
Or they could have made a royalties payment to TimeCop

But yes, it is not really mandatory for ethical business point of view the two points above.

Anyhow, we all know that these boards are designed and supported by timecop, his prices are not high at all, and shipping from Japan is ultra fast and reliable.

So, why not take a board from the creator of it ?

If you want a cheap Naze32 ... you can take a 10DOF from eBay, and take from TimeCop the nice STM32 micro development board ... just connect these two board via i2c, and you have all you need for control a copter or airplane.

adilson · Post by **adilson** » Fri Mar 07, 2014 3:44 am

Is RTH already incorporated to MultiWii 2.3 or the only working versions are the ones posted here?

TIA

felixrising · Post by **felixrising** » Fri Mar 07, 2014 4:02 am

It hasn't been picked up by Alexinparis yet... this thread is in ideas section, so probably PatrikE needs to poke Alex or Hamburger about it...

i3dm · Post by **i3dm** » Sat Mar 08, 2014 7:01 pm

Hello guys,
i would like to setup a Crius SE with Multiwii airplane on a flying wing.

PatrikE wrote:I Packed all All tools and Modified Versions I Used For Dev.
Info in the Package.
FixedWingNav.rar
All major problems is fixed and It feels Stable now.

/Patrik

Patrik - after reading around in the thread - thats a great help! thank you.
so in order to get my Crius SE board to run on my flying wing im using your DEV version and doing the following:
Multiwii:
1. define flying wing.
2. define Crius SE board.
3. define i2c_gps.

i2c_gps: flash your 2_2 version (as its eeprom backed up with a battery on my Ublox Neo6M)

MinimOSD: flash your KV version.

The above setup sould be able tp perform GPS hold (does it circle around the spot?) and RTH ?
Also what does it do in RTH? just fly back home in a steady altitude or... ?

Did i miss anything?
BTW which Ublox configuration file does this work with?

i3dm · Post by **i3dm** » Sat Mar 08, 2014 11:12 pm

Patrik,
I have actually found the TXT file and read it - and configured everything but i can not get my Ublox GPS to speak to the i2c_gps patched version.
in voth 2.1 and 2.2 of i2c_gps patched, i defined Ublox 115200 and loaded the Ublox config file in your folder (which defines Ublox protocol and 115200) but once the module flashes a locked GPS signel, the i2c_gps adapter is still flashing a red light slowly (i believe it should be blinking 3 times like in my Multiwii Quad).

Can you offer some assistance in getting a Ublox Neo6M to speak to the i2c_gps patched version?

Here is how i defined V2.2 of i2c_gps patched:

//////////////////////////////////////////////////////////////////////////////
// i2C comm definitions
//
#define I2C_ADDRESS 0x20 //7 bit address 0x40 write, 0x41 read

/* GPS Lead filter - predicts gps position based on the x/y speed. helps overcome the gps lag. */
#define GPS_LEAD_FILTER

// Special Mode for use with FixedWing
//
#define FIXEDWING // Patches for Navigation on Fixedwing.
#define I2CPATCH //Corrects OSD data and Navigation on Fixedwing.

/* Serial speed of the GPS */
#define GPS_SERIAL_SPEED 115200
//#define GPS_SERIAL_SPEED 38400

/* GPS protocol
* NMEA - Standard NMEA protocol GGA, GSA and RMC sentences are needed
* UBLOX - U-Blox binary protocol, use the ublox config file (u-blox-config.ublox.txt) from the source tree
* MTK_BINARY16 - MTK binary protocol (DIYDrones v1.6)
* MTK_BINARY19 - MTK binary protocol (DIYDrones v1.9)
* MTK_INIT - Initialize MTK GPS (if MTK_BINARY16 or 19 is not defined then it goes to NMEA, otherwise it goes for binary)
* With MTK and UBLOX you don't have to use GPS_FILTERING in multiwii code !!!
*
*/

//#define NMEA
#define UBLOX
//#define MTK_BINARY16
//#define MTK_BINARY19
//#define INIT_MTK_GPS

//////////////////////////////////////////////////////////////////////////////
// Sonar support. Based on code mods from Crazy Al
// Connect Sonar trigger to PC3 (arduino pin A3) and echo output to PC2 (arduino pin A2)
// Supported sonars :
// Ping/Pong type sonar modules such as HC-SR04, SRF-04, DYP-ME007 and many others...
// PWM output continous sonars such as the MAXBOTIX series (connect pin2(PWM out) of the sonar to PC2

//#define SONAR // USE Sonar

//Sonar type uncomment only one at a time
//#define PINGPONG
#define MAXBOTIX_PWM // PWM output mode sonar

felixrising · Post by **felixrising** » Sun Mar 09, 2014 6:38 am

BTW.. those Afromini 32's are fresh out of the oven and back in stock. I just picked up a couple.