Abstract: While hydraulic coupling for changing speed is the control element,the dynamic property influences the dynamic process of all the system.For example,the slay mud pump liquid level control system by hydraulic coupling,becomes bad.This paper puts forward the MRAC-PID control method which simpifies the design of conventional model reference with the adaptive control system.The control method has been testified possible and practical by a lot of emulation and imitation experiments.

Key words: hydrodynamic control system, hydraulic coupling, adaptive control system