The simulation on this page shows that it is possible
to control the geometry of a global constellation using
an underactuated and bounded control system. We utilize
the same initial network of 100 balloons, but we apply
an algorithm called "Paired North-South Zonal Control,"
which is described as follows:
- Zones are defined as -90 to -45, -45 to 0, 0 to
45, 45 to 90 latitude.
- Define the target number of balloons in each zone
as 15, 35, 35, and 15, respectively.
- Every four hours, count the number of balloons
in each zone.
- If the actual number differs from the target, specify
balloons to be moved from nearby zones, give them
the appropriate control instructions, and remove them
from paired North-South control.
- Continue moving these balloons that are under zonal
control until the destination zone is reached.
- For those balloons not under zonal control and
whose nearest neighbors are not under zonal control,
apply paired north-south control.
Paired north-south control is defined as follows:
- Only apply control when a StratoSat is closer than
2000 km from its nearest neighbor
- The control direction (when applied) is either
north or south, nothing else.
- If a StratoSat is north of it's nearest neighbor,
it is commanded north.
- If a StratoSat is south of it's nearest neighbor,
it is commanded south.
- Re-evaluate control for each StratoSat every 4
This movie goes for 120 days like the free-floating