Accurate mode control based on inerter array of large unmanned underwater vehicle propulsion motor floating raft system

Inerter is a basic two-terminal dynamic element. To explore the theory of inerter and obtain new mode control method of large unmanned underwater vehicle propulsion motor floating raft system, novel accurate mode control based on inerter array is proposed. First, accurate mode control based on triangular inerter array is researched. Then, method of accurate mode control based on rectangular inerter array is explained. Then, accurate mode control based on cross inerter array is researched. Dynamic models and accurate mode control methods are verified by experiments. The percentage deviations between experimental and theoretical natural frequencies are within 12%. It is concluded that accurate mode control based on inerter array is effective. Triangular inerter array and rectangular inerter array with equal inertances and nonzero distances must change all points to change a mode. Isosceles triangular inerter array which contains zero distance and cross inerter array need to change two points to change a torsional mode. Inerter arrays with a centroid inerter can accurately change the translational mode.