Fig. 13. Gain crossover frequency (_gc), phase crossover frequency (_pc), gain margin (GM), and phase margin (PM) of the measured bumblebee system. _gc is defined as the frequency that produces a gain of 0 dB, and _pc as the frequency that produces a phase of -180°. GM is the difference between the gain curve and 0 dB at _pc, and PM is the difference in phase between the phase curve and -180° at _gc. The dynamic stability of a control system can be quantified on the basis of GM and PM. When both GM and PM are positive, the control system is dynamically stable. Our results (GM20 and PM45) indicate that the measured bumblebee system has substantial dynamic stability.