抄録
A water hydraulic system has many benefits compared with other existing drive systems. Its greatest merits with respect to application to the manufacturig plants are its environmental friendliness and non flammability. On the other hand the control problems arising in water hydraulics are serious because this system has greater friction compared to oil hydraulics which has a good control performance. In this research, several robust controller design approaches were examined and compared for the water hydraulic servo motor system.
In this paper as the second report, the control performances with a disturbance—observer—type control and a sliding mode control are discussed and examined. The former algorithm estimates the disturbance to be one of the system state based on the difference between a nominal and real system, and uses it to cancel the disturbance directly. On the other hand, the latter constrains the system states to a designed hyperplane which satisfies the desired dynamical properties. In spite of the fact that these methods are often applied to the oil hydraulics, no papers have reported on how they are effective for a water hydraulic system. Moreover a controller combining both strategies was also applied to the system. The experimental results show that the combined controller gives better performance in terms of rotational angle control than H∞ design method.
