Magnetorheological Fluid Technology

171MR Applications for Vibration and Impact Control

6.3.2 Collision Mitigation

A vehicle system is simplied to chassis, engine room, and bumper. Its motion

is assumed to be in one direction. Figure6.16 shows the vehicle model with

the MR impact damper that has 3 degrees-of-freedom [28, 29]. The vehicle

model includes an occupant model that has 2 degrees-of-freedom consider-

ing the upper and lower part of the body [30]. Therefore, the dynamic model

of the vehicle system including occupant is derived as:

2 ( ) 2

2 ( ) 2 ( )

2 ( ) 2 ( sin )

( sin ) ( ) cos

( sin ) cos sin

1 1 1 1 2

2 2 1 1 2 2 2 3

3 3 2 2 3 3 3 4

4 4 3 3 4 2 4 3 5

5

2

3 3 4 5

M x k x x F