Multicopter waypoint mission flight smoothing

[cptX]

Current Behavior

I fly my multicopter to missions trying to get some nice videos. Unfortunately the multicopter jumps abruptly at every waypoint especially at terminal ones (eg waypoint 3 at my image). I have tried to find the parameters that affect this but didn't succeeded. With my fixed wing I increased the Loiter radius and the waypoint tracking accuracy to 8-9 and it really made the turnings smoother, but I cannot find any setting to make the flight smoother for the multicopter. Is it lack of documentation, lack of my knowledge or really lack of implementation?

Desired Behavior

Suggest or introduce ways or parameters to make the turns at waypoints smoother for multicopter mission flights.

Suggested Solution

Although I haven't yet dived in the INAV code, I image the solution as the following: Introduce a parameter like "smoothing rate" only used during waypoint mission flights which could apply to the commanded rate of angle change of every axis (pitch, roll, yaw). This parameter could be a percentage of the target rates commanded from the fc to catch the target path. This would mean that the banking angle for example would change only at a x% rate of the max angle set up for the roll axis during turns. This should not affect the stability of the aircraft (should not affect the flight PID) , but only the commanded rate to move the aircraft to the needed path... Not sure if my words here have any implementational meaning but I needed to start from something.

[breadoven]

What do you mean by "jumped" at the waypoints ? You can change the speed behaviour at waypoints so it doesn't slow down abruptly then speed up again after turning ... can be turned off via setting nav_mc_wp_slowdown.

[cptX]

@breadoven the change of movement (especially roll and yaw) is very abrupt at the waypoints where it changes directions. It doesn't change direction like a human pilot would do, it just tries to change the direction very fast. I don't want to slowdown my forward velocity, I just want to make turns slower/smoother.

[breadoven]

nav_mc_wp_slowdown is ON by default so unless you've changed it to OFF it will slow down at turns giving the jerky behaviour. Set it to OFF and the turns should be smoother and more flowing.

[ForkMeister]

Hi! It seems like I'm having the same problem, the turns for my multirotor are way too sharp, especially if i want it to cruise at a fairly high speed(60kph). The multirotor tries to abruptly stop at each waypoint(even with nav_mc_wp_slowdown off) , most of the time it starts to head to the next point before it has time to stopping fully. Im I doing something wrong? My waypoint radius is set to 25m and tracking accuracy to 9.

[breadoven]

Hi! It seems like I'm having the same problem, the turns for my multirotor are way too sharp, especially if i want it to cruise at a fairly high speed(60kph). The multirotor tries to abruptly stop at each waypoint(even with nav_mc_wp_slowdown off) , most of the time it starts to head to the next point before it has time to stopping fully. Im I doing something wrong? My waypoint radius is set to 25m and tracking accuracy to 9.

nav_wp_radius should be set much lower, closer to the default for a multirotor (1m only). This is how close the copter needs to get to the WP in order for it to be reached before moving on to the next WP.

nav_fw_wp_tracking_accuracy is a fixed wing setting only. It does nothing for a multirotor. That's what the fw stands for.

If setting nav_mc_wp_slowdown to OFF doesn't help then I'm not sure what the issue is other than nav_wp_radius being too big possibly.

[ForkMeister]

Hi! It seems like I'm having the same problem, the turns for my multirotor are way too sharp, especially if i want it to cruise at a fairly high speed(60kph). The multirotor tries to abruptly stop at each waypoint(even with nav_mc_wp_slowdown off) , most of the time it starts to head to the next point before it has time to stopping fully. Im I doing something wrong? My waypoint radius is set to 25m and tracking accuracy to 9.

nav_wp_radius should be set much lower, closer to the default for a multirotor (1m only). This is how close the copter needs to get to the WP in order for it to be reached before moving on to the next WP.

nav_fw_wp_tracking_accuracy is a fixed wing setting only. It does nothing for a multirotor. That's what the fw stands for.

If setting nav_mc_wp_slowdown to OFF doesn't help then I'm not sure what the issue is other than nav_wp_radius being too big possibly.

First test was with the diameter at 1m, the amount of pitch and throttle it gave to stop at the point was insane, even with slowdown off. It seems like INAV ignores that setting, but I will try today with INAV 8, cause right now I was flying on 7.1.2. If this persists I will open a bug report.

[breadoven]

Would be useful if you can provide a settings Diff and the WP mission being flown.

[ForkMeister]

It was still wierd on INAV 8, but it might be better, there was a lot more wierdness induced by a bad compass placement, since i had switch setups for INAV 8. Anyways here is the dump INAV_8.0.0_cli_20250116_165004.txt And here is the .mission file(opened in notepad and copied): <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <mission> <version value="2.3-pre8"/> <mwp cx="23.9512396" cy="56.8560646" home-x="0" home-y="0" zoom="16"/> <missionitem no="1" action="WAYPOINT" lat="56.8560646" lon="23.9512396" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="2" action="WAYPOINT" lat="56.8558456" lon="23.9519835" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="3" action="WAYPOINT" lat="56.8558612" lon="23.95257" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="4" action="WAYPOINT" lat="56.8559472" lon="23.9532995" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="5" action="WAYPOINT" lat="56.8564009" lon="23.9541578" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="6" action="WAYPOINT" lat="56.8569171" lon="23.9551878" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="7" action="WAYPOINT" lat="56.8573629" lon="23.9561462" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="8" action="WAYPOINT" lat="56.8592633" lon="23.9602375" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="9" action="WAYPOINT" lat="56.8602878" lon="23.9610529" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="10" action="WAYPOINT" lat="56.8609105" lon="23.96101" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="11" action="WAYPOINT" lat="56.8613758" lon="23.9601803" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="12" action="WAYPOINT" lat="56.86154" lon="23.9590144" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="13" action="WAYPOINT" lat="56.8615987" lon="23.9577198" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="14" action="WAYPOINT" lat="56.861454" lon="23.9567256" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="15" action="WAYPOINT" lat="56.8609418" lon="23.9559388" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="16" action="WAYPOINT" lat="56.8598743" lon="23.9559603" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="17" action="WAYPOINT" lat="56.8591587" lon="23.9557457" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="18" action="WAYPOINT" lat="56.8588029" lon="23.9555526" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="19" action="WAYPOINT" lat="56.8583884" lon="23.9549947" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="20" action="WAYPOINT" lat="56.8579269" lon="23.9538074" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="21" action="WAYPOINT" lat="56.8577275" lon="23.9531064" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="22" action="WAYPOINT" lat="56.8575711" lon="23.9521265" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="23" action="WAYPOINT" lat="56.8572348" lon="23.9512825" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="24" action="WAYPOINT" lat="56.8566795" lon="23.9508748" alt="50" parameter1="0" parameter2="0" parameter3="0" flag="0"/> <missionitem no="25" action="JUMP" lat="0" lon="0" alt="0" parameter1="1" parameter2="-1" parameter3="0" flag="165"/> </mission>

[GenCodeInc]

Until we get Spline aka curved waypoints like in Litchi and Ardupilot we will not see truly smooth quad turns on waypoints in iNav.