Magnetorheological Fluid Technology

88 Magnetorheological Fluid Technology: Applications in Vehicle Systems

states, –1 and 1, corresponding to the opposite polarization of a ferromag-

netic material. The output of the adopted relay is either 0 or 1. This is suit-

able for modeling hysteresis of an MR damper where the output (damping

force) varies between zero and a maximum value. In this case, a hysteresis

loop is located in the rst quadrant of the input-output (current-damping

force) plane. The Preisach plane can be geometrically interpreted as one-

to-one mapping between relays and switching values of (α, β) as shown

in Figure4.18(b). The maximum damping force restricts the plane within

the triangle in Figure 4.18(b), where α

0

and β

0

represent the upper and

lower li