It seems to be useful to apply the model reference adaptive control (MRAC) method for pneumatic servo systems. Since pneumatic servo systems are easily effected by the change in system parameters such as the load mass or supply pressure, etc.
The MRAC method for the pneumatic cylinder position servo system using a diaphragm-type electro-pneumatic converter is proposed in this paper. The converter acts with a very short lag time and has a simple first order transfer function. So the total transfer function of the servo system can be represented to the lower order system and this is suitable for the execution of MRAC.
The experimental tests were carried out by using a 200-mm stroke and 40-mm bore single rod-type air cylinder. The reference model was set to the second order system which has an optimal dumping factor. Also, the response of the MRAC was tested under the various input conditions such as a rectangular signal, sinusoidal signal or triangular signal was yielded, respectively.
As a result, the accommodations for the change in load mass, supply pressure or magnification of servo amplifier could be clarified.