Unable to reliably repeat missions

Now that my loiter performance is rock solid using AC 2.8.1, I’ve moved onto flying missions.  So far, only about 40% of mission sorties are a success. My basic mission is 1) takeoff, 2) Delay, 3) Time Loiter at new location for 5 seconds, 4)  Land.  I’ve tried other commands with similar mission success results.


For my quad, poor mission performance is due to two issues:  Questions about commands behavior not answered by the wiki and technical issues with my quad.   Any help is greatly appreciated!


Questions not answered by the wiki:

1)  What is the difference between the Waypoint and Time Loiter commands?   Is the Time Loiter command the same as a Waypoint command with a delay specified?  They seem to be overlapping behaviors.  I’m not sure when to use one or the other.


2)  How is Home used ?  If I set a home in a mission plan via the mission planner, is that home location used for RTL?  Or is home set once the copter is armed?    I just don’t see why home is important.


3)  When Waypoints are read from the quad, what is the purpose and function of the dialog that asks “Reset Home to Loaded Coords?”.  I don’t see a difference in behavior between answering yes or no to that question.    Just not sure what home is used for and the wiki doesn’t really explain it.


3)  What is the “Home Tracker” option in the mission planning drop down list?


4)    “condition_delay” doesn’t work for me.  I assume it waits for a timer to end and then continue with the next mission step.  It does nothing in my mission.  How is it supposed to work?  I may have a general issue with not understanding what the “condition” commands do.  Do they need a “condition” command after each condition command?  I guess I don’t understand what conditions the “condition” commands work. 


Technical Issues with my quad:

5)  About one third of the missions takeoff properly (very quickly) but when the copter reaches the target altitude and points toward the next waypoint, the copter starts to descend while moving toward the next waypoint. I have to intervene by moving to Stabilize mode before it hits the ground.     Any idea why this might happen?


6)   About 50%  of my missions execute very well with a very quick assent to the target altitude on takeoff.  The other 50% start out with takeoff very slowly – sometimes just hovering at 1 meter and sometimes ascending slowly up to the planned altitude and then erroneously descending.  Why does it sometimes work and sometimes not work under the exact same conditions.


Thanks in advance for your thoughts on the above.  Not being able to repeat missions is very frustrating.  Also, I think the wiki could be improved to explain some command behaviors in a number of areas.  I can help update the wiki once I figure out the answers to the above questions if desired. 

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  • 3).  The is the location of the antenna tracker if you want it to have a different location than your home location.  Your tracker will use your home location by default if this is not set.

  • 100KM

    I'll answer the ones I know :

    2) Home is set when you arm the copter and have 3D gps lock.  Note that 3D lock on the copter is not the same as 3D lock on the gps (mediatek).  The blue led on the mediatek will be solid before you get a 3D lock on the copter (red led solid).  That's because the copter waits for the gps to have a few (I think 10) good positions before it accepts it as a lock.

    If you arm without 3D lock, then home will be whenever the copter gets 3D lock.

    So a home that is set in mission planner is always overridden in arducopter when you arm.  In arduplane there is no arming and its a different story.

    3) Answering yes will reset home in the missionplanner to the home that is loaded in the copter eeprom (so the home from the last arming with gps lock).  Answering no will keep the home in mission planner to the one that was set in mission planner.   If you write waypoints, home will be written to the copter.  But it will be reset when copter arms (see 2) )

    Home is important for arducopter to know it's home altitude (or it's zero relative altitude).  Also it is where the copter flies to when RTL is engaged (either manually or by failsafe or mission commands).  It also serves as the basepoint for supersimple mode.

    3) I think his is where your antenna tracker is positioned.

    5) Normally the copter compensates for the loss of lift when pitching forward.  Might be that for your copter it doesn't do it enough.  I have had this too in high winds, where the copter had to pitch very hard to fly against the wind.

    6) Have you tried hoovering first for a minute orso ?  The copter dynamically adjusts its hoover throttle, based on flying in stabilise.  Might be that your hoover throttle was still too low.

    Hope this helps some.

  • T3
    I would also be interested on the diffention of home setting. What are the specs on your quad? Do you have sonar?
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