“…For example, traditional control methods like negative velocity feedback control [4][5][6], positive position feedback control [7][8][9][10], PID control [11][12][13][14] and bang-bang control [15][16][17]; modern control methods such as Lyapunov control [18,19], linear quadratic regulator (LQR) control [18,[20][21][22] and linear quadratic Gaussian (LQG) control [20,[23][24][25][26]. There are also some advanced control and intelligent control methods which can be found in the literature, for instance, sliding model control [27,28], model predictive control [29,30], fuzzy logic control [31,32] and neural network control [33][34][35]. Nevertheless, these control methods cannot suppress vibrations very efficiently because external disturbances are not considered in the design of these control methods, which are exactly the major cause of vibrations.…”