Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
searchwing-px4-analyse [2018/10/28 22:40] natwati [Points that require discussion] |
searchwing-px4-analyse [2018/10/28 23:41] natwati [Points that require discussion] |
||
|---|---|---|---|
| Line 41: | Line 41: | ||
| In case actual position waypoints are used (and not loiter waypoints) the position controller will use the logic documented in "A New Nonlinear Guidance Logic for Trajectory Tracking" (S. Park, J. Deyst, and J. P. How, Aug 2004). The L1 distance defined in the default parameter only allows an offset correction of about 70% within 5 seconds (and 90% within 10s). This would be a 100 (200) meter distance for a ground speed of 20 m/s. | In case actual position waypoints are used (and not loiter waypoints) the position controller will use the logic documented in "A New Nonlinear Guidance Logic for Trajectory Tracking" (S. Park, J. Deyst, and J. P. How, Aug 2004). The L1 distance defined in the default parameter only allows an offset correction of about 70% within 5 seconds (and 90% within 10s). This would be a 100 (200) meter distance for a ground speed of 20 m/s. | ||
| - | The PX4 firmware only supports one mission at a time. If the mission needs to be updated a full clear is required. Afterwards the mission needs to be uploaded using multiple mavlink messages and roundtrip times (see [[https://mavlink.io/en/protocol/mission.html|Mission Protocol]]). The behavior of the PX4 controlled plane during this phase still needs to be examined. | + | The PX4 firmware does not support altering an ongoing mission. This requires a full clear of the mission. Afterwards the mission needs to be uploaded using multiple mavlink messages and roundtrip times (see [[https://mavlink.io/en/protocol/mission.html|Mission Protocol]]).\\ |
| + | If all commands of a mission have been executed and the plane is in mission mode it will loiter. Missions can be paused in hold mode which causes the plane to loiter. | ||
| + | |||
| + | The PX4 firmware implements the possibility to upload a second mission in the background while another mission is active. QGroundControl does not support this and forces the user to pause the mission when uploading a new mission. | ||
| ===== Points that require discussion ===== | ===== Points that require discussion ===== | ||
| * How to command flying to a moving location? | * How to command flying to a moving location? | ||
| - | * What happens during upload of missions? | ||
| * Is an increased responsiveness of L1 position control during approach required? | * Is an increased responsiveness of L1 position control during approach required? | ||
| * A predicted route of the ship could be used to generate a trajectory that passes though all points the landing spot could be located at. This seems possible as no sudden deviation of the predicted route is to be expected for a ship. | * A predicted route of the ship could be used to generate a trajectory that passes though all points the landing spot could be located at. This seems possible as no sudden deviation of the predicted route is to be expected for a ship. | ||
| - | * Expected waves and wind (possibly from this source: [[http://users.ntua.gr/mathan/pdf/Pages_from%20_WIND_WAVE_ATLAS_MEDITERRANEAN_SEA_2004.pdf|WIND_WAVE_ATLAS_MEDITERRANEAN_SEA]] | + | * Expected waves and wind should be investigated (possibly from this source: [[http://users.ntua.gr/mathan/pdf/Pages_from%20_WIND_WAVE_ATLAS_MEDITERRANEAN_SEA_2004.pdf|WIND_WAVE_ATLAS_MEDITERRANEAN_SEA]]) |
| + | * Can geofencing provide sufficient accuracy to prevent a collision with the ship? | ||