“…It is worth mentioning that the characteristic modeling differs from the conventional model reduction methods in that all information of the original dynamic model, including uncertainties and nonlinearities, is compressed/integrated into the time-varying coefficients of the characteristic model instead of truncating parts of the plant model [28,32,33]. e timevarying coefficients of the characteristic model are referred to as the characteristic parameters [33,35,36], and the characteristic parameters are identified online adaptively [31,33,35,37]. e characteristic model-based adaptive control might be a fresh perspective in the field of adaptive control: creating simplicity out of complexity [31], and it has already been applied successfully to more than 400 engineering systems including spacecraft, e.g., the reentry control of a manned spaceship [28,29,32], the control of servo systems with backlash and friction [30], and the control for the swing arm in a Fourier transform spectrometer [38].…”