Methods and devices of the type mentioned in the introduction are known from the prior art. Motor vehicles are now frequently equipped with parking brakes that can be integrated in a particularly compact manner into the motor vehicle, in particular into a wheel brake of the motor vehicle. For this purpose, it is known by way of example to arrange an actuator on the brake caliper of a wheel brake, said actuator having an electric motor and an adjusting element, so as to be able to actuate the wheel brake independently of its dedicated actuation, in particular independently of a hydraulic actuation of the wheel brake. For this purpose, it is known by way of example to arrange an electric motor on the brake caliper, said electric motor operating by way of a gear mechanism on a brake pad or a brake piston as the adjusting element. The brake piston is displaced in the direction towards a brake disc by means of actuating the electric motor, said brake disc being connected in a non-rotatable manner to a wheel of the motor vehicle, wherein an adjusting torque is generated by means of the electric motor, said adjusting torque being exerted by way of the gear mechanism onto the adjusting element in order to achieve the desired clamping force or braking force on the wheel brake. It is known to achieve the clamping force by means of a predetermined movement path of the adjusting element. It is important to achieve the predetermined movement path both by firmly applying as well as releasing the parking brake. It is possible using knowledge of the actual movement path by way of example to set a release path or opening path of the parking brake with a high degree of accuracy so that the brake shoes safely release from the brake disc. Usually, a rotational speed sensor is provided so as to determine the movement path, said rotational speed sensor monitoring the rotational speed of the electric motor or the electric motor is operated in dependence upon time or the movement path of the adjusting element is ascertained directly by means of a movement path sensor.
USPTO Backgrounds
USPTO Backgrounds