Demo Video

We have created a video that shows the movement of the beam. The time is going 40 times faster than normal. The reference is the diameter of the sun image at the distance of the heliostat. (the green circle) The black double arrow represents a beam accuracy of 2 mRad. The movement of our first proof of concept is limited to around 4 mRad with a few interruptions on this video. We have several issues that can be improved for production versions. This shows that our concept is sufficiently accurate for the purpose.

This video show some interruptions:

Near the start between 12:44 and 13:00 the control loop is stopped a few times or the target position slightly adapted, the movement by the sun is not corrected always during this period.
Just after 13:05 the heliostat is moved to another spot and with the same direction the target spot is moved by the same amount just before 13:08.
Around 14:49 someone is interrupting the light beam.
Around 15:12 – 15:30 the algorithm switches between the magnetic compass which is less accurate and the main algorithm several times.
At 16:32 the heliostat gets into the shade of a nearby building


Another video shows the compensation of support orientation changes.
This particular video starts with a close up of the test mirror, nearly completely covered by white paper. The resulting image thus equals an unsharp image of the sun.
The next shot shows a close up of the test heliostat, where two motors can be recognized. One is an abandoned antenna rotor motor and the other is an abandoned wiper motor , driving a threaded rod. This set up demostrates that inaccurate drives, so cheap, can be used

  • The next list shows when events start / complete in this video
  • at 0:20 from start the heliostat leaves its rest position to start aiming at the target
  • at 0:53 from start the beam is at the target for the first time.
  • at 1:11 from start a person starts to insert a piece of wood underneath the support
  • at 1:53 from start the heliostat has returned the beam in steps to the target
  • at 2:07 from start the piece of wood is removed from underneath the support
  • at 2:50 from start the beam has retruned to the target position
  • at 3:24 from start the piece of wood is put underneath the support at another position
  • at 4:18 from start the beam has returned to the target
  • at 4:27 the piece of wood is removed
  • at 4:53 the beam has returned to the target
  • at 5:10 the piece of wood is put underneath the support at the third position
  • at 5:45 the beam has returned to the target
  • at 5:48 the piece of wood is removed for the last time
  • at 6:54 the beam has returned to the target
  • at 7:11 the heliostat starts to return to the rest position.