The requirement for the competitions states:
At motor burnout, the thrusters shall increase the rocket’s roll rate from 0 revolutions per minute (rpm) to 120 rpm, maintain 120-240 rpm for 3 seconds, then decrease to 0 rpm before apogee.
Since this system needs to maintain a spin rate within a large margin, the control scheme can be kept simple, using only the proportional terms of a PID function.
Originally we wanted to use PWM as the main control parameter to allow for the system to create an analog thrust signal from a digital thrust. unfortunately, I was under a major time crunch so I switched to a logic based Control system that functioned the same, but used Boolean PD logic gates to activate the thrusters
This video is the first test for the cold gas system. I decided to use an open loop control strategy where it opens the counter clockwise valve for 5 seconds and then reverses the direction for 4 seconds. The graph bellow is the results of the gyroscope data.
This was the first closed loop control test. This test failed due to timing issues (where a parameter was in milliseconds rather then Seconds) and the system turned on the wrong direction to slow down.
This was the 8th test and a complete success once the bugs were fix. Below is the data from this test with some visual goal posts of the RPM set points for the control systems.