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PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
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Kill switch for companion computer #14465

Closed cimbar closed 4 years ago

cimbar commented 4 years ago

Hi, In 1.8.2 release and before, disarming with mavlink message was possible. I was using mavros and sending mavros/State message as armed=false and it was working as same as manual kill switch. While flying in offboard mode with companion computer and not using RC controller, this was an option for emergency stop. When i passed to 1.10 version, i realized that this option is not possible anymore and returns this error: FCU: Disarming denied! Not landed If i am missing some parameter to change, i am sorry but if there isn't any possibility for emergency stop via mavlink message, i think it should be implemented. Thanks

TSC21 commented 4 years ago

You need to send the arm command with the param 2 set to 21196. https://mavlink.io/en/messages/common.html#MAV_CMD_COMPONENT_ARM_DISARM. You can use the mavcmd for that same purpose.

TSC21 commented 4 years ago

You can also extend mavsafety with that option, and its actually the best way of doing it. If you do it so, please issue a PR to MAVROS, so everyone can benefit from it.

cimbar commented 4 years ago

Following your suggestion, i used mavros_msgs/CommandLong service on /mavros/cmd/command topic inside of the code instead of using mavcmd. Also, users can call service from bash with

rosservice call /mavros/cmd/command "{broadcast: false, command: 400, confirmation: 0, param1: 0.0, param2: 21196.0, param3: 0.0,
  param4: 0.0, param5: 0.0, param6: 0.0, param7: 0.0}"

Thanks for help

julianoes commented 4 years ago

Alternatively there is also: https://mavlink.io/en/messages/common.html#MAV_CMD_DO_FLIGHTTERMINATION But for this the flight termination circuit breaker might need to be disabled.

TSC21 commented 4 years ago

Following your suggestion, i used mavros_msgs/CommandLong service on /mavros/cmd/command topic inside of the code instead of using mavcmd. Also, users can call service from bash with

rosservice call /mavros/cmd/command "{broadcast: false, command: 400, confirmation: 0, param1: 0.0, param2: 21196.0, param3: 0.0,
  param4: 0.0, param5: 0.0, param6: 0.0, param7: 0.0}"

Thanks for help

@cimbar are you interested in extending the mavsafety with the feature as well? Like a kill command?

cimbar commented 4 years ago

https://github.com/mavlink/mavros/pull/1405

DronecodeBot commented 1 year ago

This issue has been mentioned on Discussion Forum for PX4, Pixhawk, QGroundControl, MAVSDK, MAVLink. There might be relevant details there:

https://discuss.px4.io/t/how-to-disarm-drone-in-the-offboard-control/33665/1