T3

Thermopile Placement

Okay, so I'm trying to place my XY thermopile on a delta wing but have issues because of the vertical stabilizers. I don't get a clear view about 15-20 degrees off center of the two rear sensors towards the middle of the plane. Is this going to be a big deal?

If it is, I was considering putting winglets out on the tips of the plane and putting the sensor about halfway between the center of the plane and then tip to avoid what I can of the winglet. Again, at the center of the plane up front, the winglets would still be in the way of the sensor.

And one more question. If the XY sensor is place directly on the wing, will that be an issue at all for it? I ask because I know when I had it on an EasyStar, it will on the canopy where it had a pretty clear view of everything whereas on a wing, it'll have a pretty good view but it won't up off the wing much at all.

Yes, I know this is older technology but it's my way of playing around with an autopilot until I can afford an APM. I'll make due until then!

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • T3

    Okay, so I went through and made sure MIXING_MODE was set to 1 and then did 32 tests to see what was the proper setting and what could be the problem. I took REVERSE_ROLL, REVERSE_PITCH, REVERSE_ELEVONS, REVERSE_CH1_ELEVON, and REVERSE_CH2_ELEVON and set them through all the possible combinations of 1 and -1. The results are in the file I attached.

    It seems that REVERSE_ROLL and REVERSE_PITCH have no effect. Is this a bug or am I missing something?

    SF DEBUG.xlsx

    https://storage.ning.com/topology/rest/1.0/file/get/3692149112?profile=original
  • Developer

    The IR sensors have about a 60° field of view. Anything less is OK for stabilization. But limits your ability to maintain accuracy at steeper bank angles.

    Jason

  • T3

    Ahhh! Okay, so I have an issue now. I previously installed all the gear on an EasyStar and it worked wonderfully but now that it's on a delta wing, I'm having a little issue. I have the XY sensor placed up front with a pretty good view and the Z sensor is in a hole in the wing with a view of the ground and sky. The cable for the XY sensor comes out the front so I have the XY_SENSOR_LOCATION set to 0 and my ENABLE_Z_SENSOR is set to 1. My question is is there an up/down for the Z sensor (please say no!)? Also, the Z sensor does not protrude out the bottom of the wing. I have it currently mounted so the bottom of the Z sensor is about 1 cm higher than the bottom of the wing so it is far from flush but can see the ground. I did it to protect the sensor when belly landing.

    I ask these qeustions because I got everything connected up and when I put my hand in front of the XY sensor in stabilize mode, the elevons go down and when at the back two sensors, the elevons go up, which is backwards from what I would need. When my hand is put to the right of the sensor simulating the right wing pointed to the ground, the left elevon goes up and the right goes down as it should and vice versa. I suppose I could set the XY_SENSOR_LOCATION to 2 or 3 to see if that would give me what I need but I shouldn't have to do that. Any ideas what could be wrong? I attached the config file so you can take a look.

    Any help would be great as tomorrow will be another dead calm day before the snow settles in for the weekend. Thanks!

     

    AP_Config_SuperFly.h

  • T3
    This place is great! I love all the help I get here. Thanks for the quick responses Ron and Chris.
  • 3D Robotics
    It doesn't need a clear view. Just mount it on top of the cockpit and you'll be fine.
  • Kenta,

     

    I am working with an Ardupilot and thermopiles right now, on and Easy Star. It is pretty important the thermopiles have a clear line of sight "to the horizon" in order to work properly.

     

    I think as long as you have clear line of sight directly in front of the sensor, you are ok. I don't believe they "view" a wide area. I could be wrong though.

     

    Your last sentence , I could put in a post for myself. I got a really great deal on all the electronics so I can  get experience with the ardupilot before buying a APM/IMU.

This reply was deleted.

Activity