[docs] Move Orbit Wiki page

microsoft · Jun 26, 2020 · d9e6e3a · d9e6e3a
1 parent 34bb394
commit d9e6e3a
Show file tree

Hide file tree

Showing 3 changed files with 22 additions and 0 deletions.
diff --git a/docs/images/orbit.png b/docs/images/orbit.png
diff --git a/docs/orbit.md b/docs/orbit.md
@@ -0,0 +1,21 @@
+# An Orbit Trajectory
+
+Moved here from https://github.com/microsoft/AirSim/wiki/An-Orbit-Trajectory
+
+Have you ever wanted to fly a nice smooth circular orbit? This can be handy for capturing 3D objects from all sides especially if you get multiple orbits at different altitudes.
+
+So the `PythonClient/multirotor` folder contains a script named [Orbit](https://github.com/microsoft/AirSim/blob/master/PythonClient/multirotor/orbit.py) that will do precisely that.
+
+See [demo video](https://youtu.be/RFG5CTQi3Us)
+
+The demo video was created by running this command line:
+
+```shell
+python orbit.py --radius 10 --altitude 5 --speed 1 --center "0,1" --iterations 1
+```
+
+This flies a 10 meter radius orbit around the center location at (startpos + radius * [0,1]), in other words, the center is located `radius` meters away in the direction of the provided center vector.  It also keeps the front-facing camera on the drone always pointing at the center of the circle. If you watch the flight using LogViewer you will see a nice circular pattern get traced out on the GPS map:
+
+![image](images/orbit.png)
+
+The core of the algorithm is not that complicated.  At each point on the circle, we look ahead by a small delta in degrees, called the `lookahead_angle`, where that angle is computed based on our desired velocity.  We then find that lookahead point on the circle using sin/cosine and make that our "target point". Calculating the velocity then is easy, just subtract our current position from that point and feed that into the AirSim method `moveByVelocityZ`.
diff --git a/mkdocs.yml b/mkdocs.yml
@@ -94,6 +94,7 @@ nav:
     - "Moving on Path Demo": 'https://github.com/Microsoft/AirSim/wiki/moveOnPath-demo'
     - "Building Point Clouds": 'https://github.com/Microsoft/AirSim/wiki/Point-Clouds'
     - "Surveying Using Drone": 'drone_survey.md'
+    - "Orbit Trajectory": "orbit.md"
   - "Misc":
     - "AirSim on Real Drones": 'custom_drone.md'
     - "Installing cmake on Linux": 'cmake_linux.md'