2 T. Kiefer, A. Kugi, and W. Kemmetmüller, “Modeling and flatness‐based control of a 3DOF helicopter laboratory experiment,” in 6th IFAC Symposium on Nonlinear Control Systems, vol. 9, 2004.
3 Z. Li, H. H. T. Liu, B. Zhu, and H. Gao, “Robust second‐order consensus tracking of multiple 3‐DOF laboratory helicopters via output‐feedback,” IEEE Transactions on Mechatronics, vol. 20, no. 5, pp. 2538–2549, 2015.
4 B. Zhu, H. H.‐T. Liu, and Z. Li, “Robust distributed attitude synchronization of multiple three‐DOF experimental helicopters,” Control Engineering Practice, vol. 36, pp. 87–99, 2015.