Mission Planning: Mission Start missing features

Ground Control Software QGroundControl
1

Why under the mission start box when planning a mission are Flight Speed and the camera settings missing?
image What’s in the user guide
image What’s in my QGroundControl

2

The mavlink commands for these which QGC supports are not supported by ArduPilot.

3

Does the flight speed correspond to a DO_CHANGE_SPEED? ArduPilot
definitely supports that mission item. MAV_CMD_NAV_WAYPOINT doesn’t have
fields for waypoint speed, so I’m a bit confused by the interface.

Which camera messages would be need to add support for to get the
additional options?

4

The Camera Section uses the follow commands (the ones I think are missing from ArduPilot are bolded):
MAV_CMD_DO_MOUNT_CONTROL, MAV_CMD_IMAGE_START_CAPTURE, MAV_CMD_DO_SET_CAM_TRIGG_DIST, MAV_CMD_VIDEO_START_CAPTURE

Flight Speed uses: MAV_CMD_DO_CHANGE_SPEED.
I think there was something wrong with respect to the supported params for that one. Maybe the airspeed/groundspeed things. Don’t remember:

        MissionItem* item = new MissionItem(seqNum++,
                                            MAV_CMD_DO_CHANGE_SPEED,
                                            MAV_FRAME_MISSION,
                                            _vehicle->multiRotor() ? 1 /* groundspeed */ : 0 /* airspeed */,    // Change airspeed or groundspeed
                                            _flightSpeedFact.rawValue().toDouble(),
                                            -1,                                                                 // No throttle change
                                            0,                                                                  // Absolute speed change
                                            0, 0, 0,                                                            // param 5-7 not used
                                            true,                                                               // autoContinue
                                            false,                                                              // isCurrentItem
                                            missionItemParent);
5

There is also MAV_CMD_SET_CAMERA_MODE.

6

I’m sure people more knowledgeable than me can argue on the image-start and video-start ones. The video one looks benign, at least, and could be tested on something like a SkyViper. The image one… well… I’m not sure of the utility of shooting in seconds.

The speed one is a bit problematic in that Rovers do groundspeed not airspeed :slight_smile: (unless you’re doing it really right). Plane is the only vehicle that flies airspeed AFAIK (possible exception being some of the boats) - perhaps checking to see if it’s a plane would be better there.

I don’t immediately see an incompatibility, however. I do recall there being a discussion in the distant past.

7

Yeah I noticed that bug as well when I pasted this. I’ll fix it.

I believe the long exposures are used for night photography.

8

Also in poking through the ArduPilot DO_CHANGE_SPEED code I’m not quite seeing the problem as to why I disabled it. One things I saw though was that on various vehicles a number of of the parameters of that message are ignored which could lead to incorrect behavior. Seems like they should NACK if the message values are not appropriate/supported for their vehicle. Currently it looks like in some cases they will still affect speed but likely not the way the user wanted.