Analysis and design for missile of three-loop autopilot

The structure characteristic of the three-loop autopilot is analyzed and the pole placement analytic algorithm is given. In order to ensure that the system will meet the stability requirement when taking the dynamic characteristics of all the hardware devices into account, the frequency of the open-loop crossover should be constrained. Based on the pole placement algorithm, a non-linear equation with the non-dominant pole as a variable and the open-loop crossover frequency as a constraint is constructed. Solving the equation and getting the corresponding value of the non-dominant pole, the design of autopilot can be completed. Finally, through an example, it is shown that the method is convenient and practicable for the design of a three-loop autopilot.