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Guided mode equivalent for Pixhawk for indoor navigation #419

Closed aitjellal closed 8 years ago

aitjellal commented 8 years ago

Hi, I am a PhD student and currently working with Pixhawk+Mavros @vooon @TSC21 My set-up is : Pixhawk + PixIO+ Optitrack + Mavros + Onboard Mini Computer (connected via USB to Serial FTDI) + Indoor No GPS I have remapped the "optitrack, mocap" topic to "vision" and actived "vision" in QgroundControl. I checked the topic "local_position/local" and it seems that the visual position is fused with IMU data. That's fine. Now, I want to make indoor navigation (hovering , takeoff. land, Square flight )

In which flight mode should I set the Pixhawk. I read that for the "APM Software Stack" one could use the "Guided mode" http://dev.ardupilot.com/wiki/copter-commands-in-guided-mode/ and set the desired position via : SET_POSITION_TARGET_LOCAL_NED

is there an equivalent for this flight mode for "Pixhawk Stack" ?

Is it possible to takeoff (indoor) to a desired position autonomously after "arming" and switching from the manual mode?
thanks.

jlian commented 8 years ago

I use APM with GUIDED exclusively and am not too familiar with PX4 flight stack. In mavros the SET_POSITION_TARGET_LOCAL_NED is achieved with the setpoint_position plugin (see here http://wiki.ros.org/mavros#mavros.2BAC8-Plugins.). In PX4 I was under the impression that it's called OFFBOARD mode and the setpoint_position plugin should work the same way. Have you read this article https://pixhawk.org/dev/ros/mavros_offboard ?

For arming and takeoff autonomously it should be possible in PX4 as it is possible with APM. You need to set up service clients for ~/cmd/arming and ~/cmd/takeoff and also ~set_mode. This would be inside your own ROS program. From the command line it's even easier as you can just use mavcmd.

aitjellal commented 8 years ago

Thank's @jlian

can anybody confirm that the flight mode "OFFBOARD in PX4" is equivalent to "Guided in APM" ?

Would it work with the Mode "Assist -- POSCTL (position controlled) " ? https://pixhawk.org/users/system_modes

" Have you read this article https://pixhawk.org/dev/ros/mavros_offboard ?" Yes, but I did not understand what is does. I wondered that OFFBOARD is used when the user wants to implement his own controller.

I am confused, I do not know which flight mode to use. best regards.

mhkabir commented 8 years ago

confirm that the flight mode "OFFBOARD in PX4" is equivalent to "Guided in APM"

Yes

Would it work with the Mode "Assist -- POSCTL (position controlled) " ?

No. Use offboard - https://pixhawk.org/dev/offboard_control

aitjellal commented 8 years ago

thanks @mhkabir Mohammed .
so I proceed just as @jlian has described. does the command ~cmd/takeoff also work in indoor with local coordinate system NED (no gps , no global position estimate)?

aitjellal commented 8 years ago

I checked ~cmd/takeoff (mavros_msgs/CommandTOL) Send takeoff command. The ROS topic type is as follow : http://docs.ros.org/api/mavros_msgs/html/srv/CommandTOL.html

float32 min_pitch # used by takeoff float32 yaw float32 latitude float32 longitude float32 altitude

bool success uint8 result

so, I think the command "~cmd/takeoff " does only work if GPS is available.
for my indoor experiment using Optitrack, I think I can not use "~cmd/takeoff ". can any body confirm this ? @mhkabir @jlian @LorenzMeier

thanks.

jlian commented 8 years ago

I would really try to do all of these things in the simulator first before the real aircraft. You can turn off GPS in the simulator too, in pretty sure.

On Nov 3, 2015, at 12:51, aitjellal notifications@github.com wrote:

I checked ~cmd/takeoff (mavros_msgs/CommandTOL) Send takeoff command. The ROS topic type is as follow : http://docs.ros.org/api/mavros_msgs/html/srv/CommandTOL.html

Common type for Take Off and Landing http://docs.ros.org/api/mavros_msgs/html/srv/CommandTOL.html

float32 min_pitch # used by takeoff float32 yaw float32 latitude float32 longitude

float32 altitude

bool success

uint8 result

so, I think the command "~cmd/takeoff " does only work if GPS is available.

for my indoor experiment using Optitrack, I think I can not use "~cmd/takeoff ". can any body confirm this ? @mhkabir @jlian @LorenzMeier

thanks.

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vooon commented 8 years ago

Updates?

aitjellal commented 8 years ago

I can now fly autonomously using Optitrack. Thank you guys.

The "mocap" topic is remapped to "vision". I have adapted the program https://pixhawk.org/dev/offboard_control/testing for indoor use. (fly just 0.8m instead of 8m).

This program sends desired positions via "mavros/setpoint_position/local " the programm also subscribe to " mavros/local_position/local" to get the current position In order to check if the desired position is reached or not.

I have enabled the "offboard" flight mode using QGC and assigned an RC switch for it. Flight procedure :

I still have an issue, which I think is related to "parameter tuning". I did no parameter tuning. I used the default values.

The Quadcopter fly slowly most of the time to a position above the desired position. and keep going up. and then recover and go down. I this a parameters tuning problem ? or did I miss something ? Any link to good tutorials where I can learn how to solve this problem. thank you.

vooon commented 8 years ago

Did you tried to fly it manually (via RC)? If it's response is same then it is definitely PID tuning problem. My knowledge about copters is minimal, so please check manuals in px4 wiki and ask questions at px4-users.

riseio commented 8 years ago

Hey aitjellal, I am working on trying to get a similar configuration working properly but have been having some troubles. When you start publishing to "mavros/setpoint_position/local " does the light on the pixhawk go green like if you had a gps lock and stay green?

aitjellal commented 8 years ago

hi, does the light on the pixhawk go green like if you had a gps lock and stay green? no. it does not. light remains blue.

Date: Thu, 21 Jan 2016 01:47:30 -0800 From: notifications@github.com To: mavros@noreply.github.com CC: aitjellal@hotmail.fr Subject: Re: [mavros] Guided mode equivalent for Pixhawk for indoor navigation (#419)

Hey aitjellal,

I am working on trying to get a similar configuration working properly but have been having some troubles. When you start publishing to "mavros/setpoint_position/local " does the light on the pixhawk go green like if you had a gps lock and stay green?

— Reply to this email directly or view it on GitHub.