Problem with Waypoint Navigation

We tried to fly the same set of waypoints 8 times.

Twice it worked perfectly. (15050804.GPX)

Once it flew to the first waypoint and stayed there while continuing to rise at a constant rate. (13050806.GPX)

Five times it flew to the first way point and then on to the second waypoint, but failing to keep the proper altitude and instead rising at a constant rate. Upon reaching the second waypoint it would stay there and continue to rise. (13050803.GPX)

The firmware version was 90g.

I want to get some extra eyes on this. Maybe there was something the pilot was doing to cause the misbehavior. I am hoping it's a pilot error and not bug in the firmware.

 

Here is the waypoint file. I had to add ".txt" to the file to be able to upload it. You will have to remove the ".txt" if you want to load it into MKTool. However, it is a text file so you can just read it in a text editor if you want.

You can tell it's not a sensor error as the correct location of the craft is stored in the GPx file. A sudden error in the GPS reading would show up as a big position change in the GPX file. The craft was supposed to fly at an altitude of 70 meters, but you can see that it flies right through that altitude without even pausing.

 

I don't think you got to your first waypoint. Your first waypoint is at 60 meters altitude and it only got to 31 meters altitude. It was programed to go up at half a meter per second which it looks like it was doing. So that looks OK. However, it also looks like it wasn't flying in the right direction. The navi controller thinks that it's target is to the North East, but it's course is to the South East.

In this list, the first number is the course direction and second number is the direction it needed to go in order to reach the target (I think).


101 77
101 132
103 122
105 104
107 96
110 93
114 70
114 59
115 53
115 49
115 45
115 46
115 46
115 48
115 52
115 55
115 57
115 60
115 62
115 58
115 56
115 54
115 50
115 48
116 43
116 44
116 45
116 44
116 42
116 42
116 43
116 45
116 44
116 46
115 42
112 41
109 39
109 40
108 38
107 32
107 29
107 27
107 27
108 28
110 31
110 33
110 33
110 32
110 32
110 30
110 30

 

I has a similar problem with come home once. I flipped on come home and once it got to the home position it just started to go straight up. It was really high before I finally decided that something was wrong.

 

Here you go.

This was my first attempt to fly with waypoint control. I had thought that the way point program would be stored on the micro SD card, and so I programmed it in my house unpowered it and took it outside and powered it up again. Of course it lost it's program as the program is stored in the microcontrollers RAM. So instead of the running the program it only did a come home. But I thought the program was running. The first part would have been for the flyer to fly up to 30 meters and and it was going up so I just let it. Eventually, I figured out that something was going wrong.

In this flight I didn't have altitude control on. Later I decided that this might be the reason that it went up. In a later waypoint test the copter failed to point the camera at a point of interest. It flew the waypoints but didn't point the camera. It turned out that this happened because carefree control wasn't turned on. I decided that the theory of operation for waypoint flying was for the flyer to control it's coordinates it needed position hold on, for it to control it's altitude it needed altitude control on, and for it to control it's yaw it needed carefree control on. And so I figured that the reason why it flew up way past it's come home altitude was because I didn't have altitude control on and so it didn't control for it's altitude. I'm not so sure now. Altitude control was on for the all the waypoint flights that it flew up on. Maybe it was just misbehaving in the same manner.

 

I figured out what was going on here. When flying under waypoint control the CS8 is still paying attention to inputs from the remote control. And so if the throttle is above the neutral set point then the craft will go up even though the waypoint program says it should fly level.

It's too easy to tap the throttle and not realize that you have sent the craft off course until it sticks at a waypoint. However, I suppose the thinking is that it insures that the state of the transmitter is in sync with the state of the craft so that there aren't any surprises when the program ends. You could imagine a case where the CS8 falls out of the sky as you turn off the CH switch because the throttle got bumped to zero while the program was running and no one noticed. On the other, there are better ways to handle this.

Anyway, the takeaway is to steady the craft before you run the waypoint program and then don't touch the controls while the program is in effect.