The formation of the wheel braking force in the tire tread area as a result of the driver exerting a foot force along with the accompanying internal forces is shown in the figure.
The foot force FF applied by the driver is initially multiplied by the brake pedal leverage into the input force for the control device, the control force Fcon. The transmission device, which in this case is hydraulic, converts the control force which is possibly supported by a brake booster which amplifies it further, into the auxiliary force Faux which is in turn transferred as hydraulic pressure to the master brake cylinder. The brake force reaches the wheel brake cylinders via the brake lines and forms the clamping force Ft required for operating the wheel brakes. The clamping forces cause a circumferential force Fper over the friction linings at the effective braking radius r and thus a wheel brake force FBwheel in the tire tread area.
The resulting wheel brake force results from the circumferential force to:

Eq. 3-54

by the brake characteristic C*, also called inner multiplication or multiplication of the wheel brake:

Eq. 3-55

and the outer multiplication io (multiplication of the transmission device):

Eq. 3-56

we get:

Eq. 3-57


Before dealing with the components of the braking system in more detail, the fundamental regulations associated with brakes should be briefly mentioned here.