Integration Marvelmind and Pixhawk 4

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Autodrone
Posts: 1
Joined: Mon Mar 25, 2019 5:41 pm

Integration Marvelmind and Pixhawk 4

Post by Autodrone »

Hello everyone,

we are about to develop an autonomous flying drone using Marvelmind indoor GPS and the Pixhawk 4, but we have some problems with the integration of Marvelmind indoor GPS and Pixhawk 4. The Marvelmind works without big problems, but we never get the message "3D Fix" when integrating it into the Mission Planner.
We tried several integration options:

1) A first attempt was the integration according to the following link: http://ardupilot.org/copter/docs/common-marvelmind.html.
We have only made these settings in the parameter list and with the Hedgehog we use the Marvelmind protocol in the Marvelmind to send the GPS signal. After we have made all the settings, we receive the message "GPS: No GPS" in the HUD.

2) Second, we have tried the integration according to the following instructions: https://www.robotshop.com/media/files/p ... manual.pdf.
We have used the attached parameter list and use NMEA 1803 in the Marvelmind to send the GPS signal. The NMEA messages are also enabled.
Here we get the message "GPS: No Fix" in the HUD. However, any slight changes to the parameters, as indicated in some forums, will not help to get the message "GPS: 3D Fix".


For the wiring we have tried the options on the Pixhawk 4 via the Telem1 or the UART & I2C as well as the GPS connection. But we don't know which is the right alternative? We suspect it, via the GPS module.

We have tried a lot and don't know what else to do to get "3D Fix". Do you have any experience with the Pixhawk 4 and the integration of the Marvelmind GPS with the Pixhawk 4? Does anyone have any ideas about what we're doing wrong or what we can try out to make progress?

Best regards,
Autodrone

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Re: Integration Marvelmind and Pixhawk 4

Post by admin »

Autodrone wrote:Hello everyone,

we are about to develop an autonomous flying drone using Marvelmind indoor GPS and the Pixhawk 4, but we have some problems with the integration of Marvelmind indoor GPS and Pixhawk 4. The Marvelmind works without big problems, but we never get the message "3D Fix" when integrating it into the Mission Planner.
We tried several integration options:

1) A first attempt was the integration according to the following link: http://ardupilot.org/copter/docs/common-marvelmind.html.
We have only made these settings in the parameter list and with the Hedgehog we use the Marvelmind protocol in the Marvelmind to send the GPS signal. After we have made all the settings, we receive the message "GPS: No GPS" in the HUD.

2) Second, we have tried the integration according to the following instructions: https://www.robotshop.com/media/files/p ... manual.pdf.
We have used the attached parameter list and use NMEA 1803 in the Marvelmind to send the GPS signal. The NMEA messages are also enabled.
Here we get the message "GPS: No Fix" in the HUD. However, any slight changes to the parameters, as indicated in some forums, will not help to get the message "GPS: 3D Fix".


For the wiring we have tried the options on the Pixhawk 4 via the Telem1 or the UART & I2C as well as the GPS connection. But we don't know which is the right alternative? We suspect it, via the GPS module.

We have tried a lot and don't know what else to do to get "3D Fix". Do you have any experience with the Pixhawk 4 and the integration of the Marvelmind GPS with the Pixhawk 4? Does anyone have any ideas about what we're doing wrong or what we can try out to make progress?

Best regards,
Autodrone


Hello colleagues,

We will check once again what can be added or corrected. It may take some days, at least. But we will do.

Meanwhile, community, if you have good hints, please, share.

Kind regards,
Maxim

davasp
Posts: 1
Joined: Tue Jan 15, 2019 5:57 pm

Re: Integration Marvelmind and Pixhawk 4

Post by davasp »

Hi all.

We are also stuck trying to integrate marvelmind but we're using a pixhawk 2.1 (cube). We've tried any possible parameter combination on the receiving end using both NMEA and Marvelmid protocols. We could never get a positon reading using MM protocol, even after setting serial comms to "beacon" and forcing beacon type to "Marvelmind", and disabling GPS use in both EKF and AHRS.

We can get position information using NMEA, albeit with EKF flags in Velocity and position using certain parameter settings, and "Bad GPS Health" using others. Position tracking shown in Mission Planner is very jumpy and inaccurate when we use the second settings, But it tracks very well when we use the former... however, having those EKF flags, it wont let us arm in auto/loiter mode.

Please let me know how can we help, any input will also be gratly appreciated.

David.

ifiksel
Posts: 2
Joined: Thu Aug 08, 2019 4:19 am

Re: Integration Marvelmind and Pixhawk 4

Post by ifiksel »

I have been working on this issue for a few weeks now. It's still not going into position hold but we do get a "GPS lock". I connected the hedgehog to the GPS port of the Pixhawk 4.

In Mission Planner, Enable EKF3, GPS is set to NMEA (5) at 115200 (115).
Also, there is a parameter to not check for satellites

In the MM Dashboard, in the hedgehog interface, set:
Uart interface = 115200
enable all NMEA messages
enable IMU fusion for location and speed
enable processed IMU data

"Bad GPS Health" means that the GPS update rate is below 5Hz. Make sure you have a good radio connection to fix this or if you don't have the 100Hz IMU license, I recommend getting it.

If you re-calibrate the Pixhawk accelerometer and compass you will get rid of most of the errors but I still get them.

I think in order to use auto mode you need to arm in stablize mode, increase the throttle and switch into auto mode. Don't take my word on this because I have not tried this yet.

I recommend following the Marvelmind + pixhawk integration manual. The Ardupilot firmware provided in the manual is for the FMUv2 and not for the FMUv5 in the Pixhawk 4. I don't know if this is the main reason for the system not integrating. Hopefully, the admin can clarify this.

Hope this helps

avilahuerta
Posts: 4
Joined: Sat Dec 21, 2019 2:34 pm

Integration Marvelmind and Pixhawk 4

Post by avilahuerta »

After setting up my starter kit (the Starter Set Super NIA-3D), i am now going to integrate it in my drone project. As far as I have seen in the forum, there seems to be two possibilities:

1.- Connect the hedgehog to the pixhawk control board using the GPS port and follow the instructions of
https://www.robotshop.com/media/files/p ... manual.pdf.

2.- Connect the hedgehog to one of the pixhawk telemetry ports (in my case it will be telem2 as I am using telem1 to conect a wifi module) and follow the instructions of ardupilot documentation found in http://ardupilot.org/copter/docs/common-marvelmind.html.

If I follow the first option, it seems that I have to install an specific autopilot SW (found in https://drive.google.com/file/d/0B7tPlr ... sp=sharing as the integration manual says). This SW version seems not to be up to date with latests ardupilot SW, and uses a set of parameters specific to this version that might not be the same I have in my drone (which is already calibrated and flying without marvelmind).

I have two questions: first which of the two options is recommended?; and second: is it possible to connect to the GPS port and follow the instructions of https://www.robotshop.com/media/files/p ... manual.pdf but using an standard ardupilot delivery (the last stable one)?

I would appreciate any suggestions on this. My first attempt will be option 2, so I do not modify the existing sw in my drone.

Thanks

smoker77
Posts: 327
Joined: Sat Feb 06, 2016 4:03 pm

Re: Integration Marvelmind and Pixhawk 4

Post by smoker77 »

Hello,

First of these two options was tested in Marvelmind. It uses standard NMEA0183 GPS protocol, so flight controller works with Marvelmind mobile beacon as with regular GPS receiver. In manual we refer to the version of Ardupilot which we have tested, but I think more new versions should also work.

Second option is recommended by Ardupilot team. It uses non-standard Marvelmind protocol, which gives more special data to pixhawk, like distances to stationary beacons. So this option may be work better than first one, but it can work only with Pixhawk firmware supporting Marvelmind protocol (BCN_TYPE = 2 setting).

avilahuerta
Posts: 4
Joined: Sat Dec 21, 2019 2:34 pm

Re: Integration Marvelmind and Pixhawk 4

Post by avilahuerta »

Hello,

Thanks for your answer. I have started connecting the hedgehog to the GPS port of my pixhawk. I am using Arducopter 3.6.9. After configuration of both Marvelmind system and ardupilot, I get stable and accurate 3D tracking in dashboard.

However, in ardupilot, I have acuurate 2D tracking (X,Y) but not in Z (height). I receive the message GPS 3D fix in mission planer, and 2D tracking seems to work properly. But height readings are not good and are not stable while in dashboard Z readings are OK and stable.

Any hints on what might be going on?.

Thanks

smoker77
Posts: 327
Joined: Sat Feb 06, 2016 4:03 pm

Re: Integration Marvelmind and Pixhawk 4

Post by smoker77 »

Hello,
May be Pixhawk is configured for using barometer or IMU or some another sensor for getting altitude instead of data from Marvelmind system?

avilahuerta
Posts: 4
Joined: Sat Dec 21, 2019 2:34 pm

Re: Integration Marvelmind and Pixhawk 4

Post by avilahuerta »

Hello

Thanks for your answer. In fact I have made some progress. I had the EK3_ALT_SOURCE configured as 3 (use beacon) and this was causing apparently the problem. I have changed it to 2 (meaning use GPS) and now it works better. At least I have stable readings of absolute altitude, consistent with the ones I see in dashboard. There is however a small difference (a few centimeters) between the values for Z as I see in dashboard and the absolute altitude I see by asking ardupilot (I use a python program to read the values). Latitude and Longitude seem to be ok.

I will try additional modifications in ardupilot parameters (mainly those related to EK3).

By the way, did anyone try to disable EKF when using Marvelmind as GPS? Does it work?

Thanks

avilahuerta
Posts: 4
Joined: Sat Dec 21, 2019 2:34 pm

Re: Integration Marvelmind and Pixhawk 4

Post by avilahuerta »

Regarding impact of accuracy of North alignment in Marvelmind and drones and in general de use of Marvelmind for autonomous control of drones indoor, I would like to share the following with the community:

I have connected the hedgehog to the drone pixhawk controller using the
GPS port, and I have stable readings of position both in dashboard and
in the drone controller. Drone controller has a 3D fix of position and
height (provided by Marvelmind system).

However, when I issue flight commands to the drone (takeoff, mission
positions) I get drifts in the positioning. I first thought that this
was due to miss-alignment between the North direction of the drone
(calculated by its internal compass) and the North alignment of
Marvelmind (defined by the Y axis in dashboard as far as I understand).
I have rotated the dashboard map by changing the value of the "submap
rotation, degrees) as indicated in the marvelmind manual, and it seems
to work better although drifts in position still occur. The drone should
stay stable in a position and height (with only small changes that are
compensated thanks to the information received by the pixhawk drone
controller via marvelmind and GPS interface) but this is not the case. I
was wandering if this might be due to small differences in North
alignment, that in practice are impossible to avoid.

Has anyone succesfully solved any issues, so drones lock in position and height in an stable way?. I would appreciate any suggestions.

Thanks

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