An Electronically Controlled Shock Absorber Using Electrorheological Fluid

Electrorheological (ER) fluids, sometimes called “smart” fluids, are materials having flow properties that can be modified with electric field. This unique behavior is utilized in the design of a shock absorber with fast-acting electronic control. The damping force of the shock absorber is adjusted by selectively applying voltage to the ER fluid. In this paper, data are provided to illustrate that the damping forces needed for an automobile suspension are achieved using a device with realistic package size and power requirements. The data also demonstrate that the prototype shock absorber performs consistently in a durability test where the conditions are typical for life testing of commercial shock absorbers. The prototype is observed to operate successfully on a vehicle as a retrofit for an original equipment shock absorber with variable damping.