Safe Landings in Tight Spaces

Landing on your back porch? In close proximity to trees? And near your grandmother? :) 

We produced documentation regarding the 'Precision Landing' developments (link). The primary intent of this development is to enable more industrial use-cases for multi-copters, namely, fully automated systems with auto re-charge capabilities. However, it is also useful for assisting manual landings in tight spaces. I typically would not attempt to land on my patio, near a house, under a tree, and on a table. 

The assisted landing uses a Sensor/Beacon system (link) to center the IRIS+ over the IR Beacon when in Loiter or Land flight modes. In the above video, we are using a modified version of AC3.2.1 which uses readings from the Sensor/Beacon system. In short, if the Sensor detects the Beacon, the copter will hover over the Beacon. If the Beacon is not detected, the copter operates as expected in Loiter/Land.

Loitering over a Beacon is demonstrated in the video below.

Randy shot a very nice video of a precision landing. This development will not be in the AC3.3 master. We are still experimenting .... Also, note that the 3.3-based version (demonstrated below) is somewhat different than the 3.2.1 version. You can read more about it here (link). 

I am also curious about the use-cases for fixed wings. We have had requests about this, but my knowledge on the matter is limited. Feel free to shoot me a message (thomas at irlock dot com), or reply below. 

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  • Could this be implemented on Arduplane for net landings?

  • @OG Yes, a larger gimbal would probably do the trick. For smaller gimbals, it would be better to break out the camera sensor (like in the Percepto product or FlytheShift).

    @Nick Excellent. 

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  • Thomas, great videos. I have received my new IR-Lock beacons this week and will post a follow up video with my experiences.

  • @OG

    Thanks. Are you talking about the older videos? The IR-LOCK Sensor (modified Pixy) actually has servo outputs built into the board. So we directly controlled two servos with a simple PD controller programmed on the Sensor. 

    Unfortunately, we never had time to integrate it into a 'nice' gimbal with brushless motors. The challenging part was mounting the Sensor (~30g) onto the gimbal, without upsetting the balance.

  • Developer

    Thomas, great to have the docs.

    @Doug, I think the small overshoot issue is that the controller needs to be changed from a position controller (i.e. the sensor's output is converted to a new position to land on) to a velocity controller (the output is converted to a 3D speed).  We discovered this with the red-balloon-popper as well - we don't know exactly how far the target is but we do know what direction it's in.  So as long as we have a velocity vector that points at the target we will hit it.  It's not a big change though and I think it'll all be included in AC3.4.

  • @Doug

    Yes, you are definitely correct on that point. When we completed Precision Landing 'missions' (link) w/ our 3.2.1 code, there was a actually a loiter delay, which allowed the copter some time to get centered before descending.

    It is still a work in progress. Currently, we do a lot customized coding to fit particular applications. 


  • Just a suggestion for your precision landing process.  I noted Randy had moved the copter off from overhead the IR beacon on the ground and when he activated the Precision Land mode it descended with two-three overshoots.  I would recommend that the copter not start its descend until it is directly overtop the beacon, this way you don't have to worry about clipping something as it is coming down in tight areas. 

  • Hi OG,

    That is a good question. Have you seen this documentation?

    It includes most of the basic info. Let me know if you need more details on a particular topic.  

    Precision Landing | Beacon docs
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