Electro-rheological fluid controllers

The paper proposes two new fluid controllers based on the properties of the ER fluids. The first controller is a modulated width pulse system in which the control variable is the duration of the input signal with constant amplitude. An ER valve with an on/off function assures the pulse width modulated signal. This valve operates as a hydraulic semiconductor controlled by a high-voltage signal. The second controller is developed like a new control system based on a mixed control: a conventional control of the fluid pressure and a centralised and sequential distributed viscosity controller. The stability of the motion is proved and the conditions of the trajectory control on the switching manifolds are determined. Two viscosity control procedures are used: a lumped control and a sequential distributed control which allows the decomposition of the system in a finite number of a lower dimension problems. The numerical simulations are presented.