Drone decelerating when getting closer to the waypoint in Missions

[SouSageYa (Fatih Serdaroğlu)]

Hey Guys! It is me again. I’m Currently testing a 3DR IRIS Quadrotor on a Mission I drew. It is slowing real hard when getting closer to the waypoint. What is this problem is it about the parameters ??

[dkemxr (Dave)]

There is a fix coming for that.

S-Curve Progress

Hi all, I thought some people may be interested in the progress we have made with the development of S-Curve navigation. We have got the first proof of concept working and so far it is living up to all my expectations. Here is a video showing the performance of 4.0 navigation. This video highlights the problems with the current approach when we use low accelerations and high speeds. The first half of the video looks pretty good because the acceleration is only 1/3 the speed. When the acceler…

[SouSageYa (Fatih Serdaroğlu)]

So you say that there is no fix for that situation

[dkemxr (Dave)]

It’s expected behavior. You can try adding a small delays at the Waypoint, increase WPNAV_ACCEL and reduce WPNAC_SPEED.

[SouSageYa (Fatih Serdaroğlu)]

Hey! It is me again. Do you have any info about QGroundControl ? I’m planning to draw my autonomous missions on QGround but as I Expected I ran into the same problem.

[dkemxr (Dave)]

I typically only use QGC as an In-Flight Ground Control Station on IOS. There is a forum thread for QGC.

[Notorious7 (just_curious)]

If I am flying quadcopter in guided mode and I send mavlink message in guided mode continuously(every half a second) to go to a certain coordinate then it will keep accelerating and decelerating continuously everytime it get the same location mavlink message ?

[Emre_Saldiran (Emre Saldıran)]

You should not be sending position target continuously. There is no timeout like posvel or velocity target while sending only target position.

[SouSageYa (Fatih Serdaroğlu)]

Could you please explain a little bit more. I could not understand what did you mean.

[Emre_Saldiran (Emre Saldıran)]

As stated in here SET_POSITION_TARGET_GLOBAL_INT, type_mask tells Ardupilot to how to interpret the data.

If you use type_mask of 0b110111111000 meaning position only, vehicle will be guided towards target points as if it is doing wp navigation in AUTO mode. Also see goto_position_target_global_int in dronekit.

İf you use typemask of 0b110111000111 or 0b110111000000 meaning velocity only or position and velocity, these methods requires you to send new reference message at most 3 seconds interval. This 3 seconds is hardcoded as GUIDED_POSVEL_TIMEOUT_MS. Also see send_global_velocity in dronekit.

[quote=“SouSageYa, post:1, topic:66976, full:true”]
Hey Guys! It is me again. I’m Currently testing a 3DR IRIS Quadrotor on a Mission I drew. It is slowing real hard when getting closer to the waypoint. What is this problem is it about the parameters ??
[/quote] For your original question, you might wanna try spline waypoint until the S-curve PR is merged.

[Leonardthall (Leonard Hall)]

@dkemxr

There is a fix coming for that.

Yes, S-Curve navigation.