Zero Robotics High School Tournament 2012 (US Only)

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The following two tests are from a recent ISS test session where we demonstrated several elements of the game. We have selected these two tests to show the diferences between simulation and ISS

Cloud Maneuvering and Gravity

This test shows two satellties navigating in Zone 3. After moving to their initial positions SPH1 (Blue) moves towards a fixed target using setPositionTarget. SPH2 (RED) turns off all control and is gradually pulled into the cloud.

Animations:

Simulation
ISS
Side by side screen capture (ISS on right)

Finish Maneuver

This test shows the satellites completing the finish maneuver in Zone 3.

Animations:

Simulation
ISS

Items to note:

• Overall, estimation noise is similar to the simulation.
• You may see the blue satellite jump forward then correct backwards slightly. In this case, the satellite's actual CO2 tank was starting to get low. At each time step the internal positioning algorithm expected the satellite to be slightly farther ahead, then measurements corrected the position.
• Timing of motion is not exactly the same. The crew on the ISS sets a pressure regulator on top of the satellite control the force produced by the thrusters. If there is some error in the setting due to the accuracy of the pressure guage or changes in the tank level, there can be some variation in the satellite thrust.
• To make sure your code can tolerate variations in thrust and estimation noise, make sure you do not have overly strict timing requirements to arrive at a particular location and make sure to incorporate measurements to correct for errors in the expected motion.