US 12,420,763 B2
Method and technology for detecting and releasing iced-up brake linings of an electric parking brake
Benedikt Ohlig, Vallendar (DE); Thomas Hein, Neuwied (DE); and Michael Bergmann, Koblenz (DE)
Assigned to ZF Active Safety GmbH, Kobienz (DE)
Filed by ZF Active Safety GmbH, Koblenz (DE)
Filed on Jun. 30, 2022, as Appl. No. 17/853,995.
Claims priority of application No. 102021117276.4 (DE), filed on Jul. 5, 2021.
Prior Publication US 2023/0001907 A1, Jan. 5, 2023
Int. Cl. B60T 13/74 (2006.01); B60T 17/22 (2006.01)
CPC B60T 13/741 (2013.01) [B60T 17/221 (2013.01); B60T 2201/124 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for determining a state of a brake lining on a wheel brake of a brake system of a motor vehicle, wherein the wheel brake has an electromechanical brake actuator which is designed to build up a force acting on a brake disc of the brake system by pressing the brake lining against the brake disc, and which is assigned to a first axle of the motor vehicle, wherein the method comprises:
detecting, via a control unit, a first wheel rotation rate and/or first wheel speed of the first motor-vehicle axle assigned to the electromechanical brake actuator;
detecting, via the control unit, a second wheel rotation rate and/or second wheel speed of the second motor-vehicle axle; and
determining, via the control unit, an adhesion state of the brake lining by determining whether the brake lining is adhering to and/or stuck to the brake disc due to icing while the electromechanical brake actuator is in a released state, wherein the determination comprises:
verifying that the wheel brake and the electromechanical brake actuator are not applying any braking force to the brake disc;
verifying that an engine of the motor vehicle is in operation;
determining that the first wheel rotation rate and/or first wheel speed of the first motor-vehicle axle has the value zero while the second wheel rotation rate and/or second wheel speed of the second motor-vehicle axle is greater than zero;
determining that the second wheel rotation rate and/or second wheel speed substantially corresponds to at least one of: an engine rotation rate,
an engine speed, a drive shaft rotation rate, or a drive shaft speed of the motor vehicle; and
in response to determining the brake lining is adhering to and/or stuck to the brake disc, generating, via the control unit, a control signal for the electromechanical brake actuator to build up a force acting on the brake disc by pressing the brake lining against the brake disc and then releasing the force, thereby freeing the stuck brake lining from the brake disc by breaking up ice between the brake lining and the brake disc.