The data from the pulse sensing method results in graphs that allow us to analyze the behavior of the propellers. From these graphs, we can derive rise time, settling time, and overshoot. To test our system and ensure its effectiveness and robustness, we came up with five test cases.
Cases 1, 2, and 3 deal with speed. In all three cases the master is running at a constant speed and the slave is offset by a varying amount. The initial speed of the slave will be determined by the cases listed below.
Case 1—Low speed—approximately 120 rpm*
Case 2—Medium speed—approximately 375 rpm*
Case 3—High speed—approximately 630 rpm*
*These numbers are derived from the performance specifications of the motors we had purchased.
We have chosen to analyze the behavior of our system at different speeds because we want to make sure response time and effectiveness of the system is consistent, and, if not consistent, its performance still remains within specifications.
Case 4—One off, one on
In this case, the master propeller starts on while the slave propeller(s) start off. Case 4 checks for integration flaws. The very large initial frequency difference will enter into the PI controller and be remembered for many decision counts, if the integral term constant is too large this could lead to an excessively long settling time.