Control Characteristics of ER Devices

The successful development of a new generation of technology incorporating an electro-rheological (ER) fluid requires three principal ingredients; advanced ER fluid, reliable mechanical mechanism and efficacious control scheme. This paper discusses the third one. After describing general, but stringent requirements for semiactive or active control systems featuring the ER fluid, feedback control characteristics of some specific ER devices are presented; a frequency-dependent feedback control of mode shape in a smart flexible structure containing the ER fluid, an optimal control of vibration in a semi-active suspension installed with ER shock absorbers, and a neural network control of position in a hydraulic ER valve-cylinder system.