When the driver steps on the brake pedal, he is sending electronic message to brakes electronic module, the electronic module reads the information and responds by applying electric field on the electrorheological fluid brake units connected to the wheels.
When an electric field is applied across the electrorheological fluid, the fluid viscosity change and braking torque is generated, forcing vehicle to slow down or stop.
The ECO Brake-By-Wire system consists of rotating grooved disk immersed in an electrorheological fluid.
In principle, the brake torque can be controlled by changing the electric current applied on the electrorheologica fluid, a compound containing fine particles in suspension stiffens in the presence of an electrical current. When an electric field is applied across the gap between the disk and the housing filled with an electrorheological fluid, the fluid viscosity change and braking torque is generated, forcing vehicle to slow down or stop.
The resistance to the motion of an electrorheological fluid is controlled by adjusting applied electric field.
The electrorheological fluid provides controllable resistance of active torque output in either direction of rotation, under computer control.
Properties such as torque capacity of the brakes, the wall shear stress and relative viscosity are determined by electric field and the temperature, as well as the input angular velocity of the rotating wheel.
The yield stress of an electrorheological fluid varies as a function of the electrical field applied. The controllable yield stress causes friction on the rotating disk surfaces, thus generating a retarding brake torque. The braking torque can be precisely controlled by changing electric current applied on the electrorheological fluid, provide consistent and stable braking force.