Abstract
In a hydraulic control system(here, we call this a major control loop), a proportional directional control(PDC) valve with spool position feedback may work in minor(or inner) control loop. In this study the authors suggest control schemes to improve the performance of PDC valve control loop(a minor control loop). At first, the mathematical model for the PDC valve is obtained through an experimental identification process. Then, a dead-zone compensation scheme is devised. And the control schemes for the PDC valve are suggested so as to reject disturbances effectively, and to obtain good reference tracking ability. Finally, the suggested control schemes are verified through experiments.
