Development of Electronically Controlled Shock Absorber using Magneto-Rheological Fluid

The electronically controlled shock absorber with magneto-rheological fluid, KF-MRS07, was developed for the Formula SAE (FSAE), which is an annual collegiate racing competition. The KF-MRS07 has been newly developed based on KF-NS06, a mono-tube type shock absorber produced in 2006 incorporating commercial oil. The KF-NS06 is a low cost product but hard to adjust the damping property. On the other hand, the KF-MRS07 can be controlled electronically whose damping force is changeable instantaneously while running. The equivalent viscous damping coefficient, the measure for evaluating the shock absorbers, is changed about 99% with 1.0A applied current. On-track test results show that the yaw rates can be changed from an oversteer condition to an understeer one with a simple threshold control.