A design method of universal adaptive stabilizer

In the present paper, a design method of universal adaptive stabilizers for processes with unknown degrees and unknown signs of high-frequency gains, and with uncertain relative degrees r, r+1 or r+2 (with known r), is presented. This is an extension of Morse´s universal stabilizers where it was assumed that the relative degrees are uncertain but known to be 1 or 2. It is shown that single adaptive control schemes with 6 tuning parameters can deal with such enlarged uncertainties of relative degrees compared with the previous works, and that the resulting adaptive control systems are asymptotically stable