CN-121986041-A - Method for detecting dynamic impacts of an electric brake actuator, brake actuator for a brake system, and brake system for a vehicle

Abstract

The invention relates to a method (S) for detecting dynamic impacts of an electric brake actuator (1), comprising the step of detecting (S1) a change in the stiffness of the electric brake actuator (1) on the basis of a motor shaft torque detection (S1) of a motor (11) of the electric brake actuator (1). The invention further relates to a brake actuator (1) for a brake system of a vehicle, comprising an electric motor (11) for delivering a brake fluid, and a control device which is designed to detect a change in the stiffness of the brake actuator (1) on the basis of a motor shaft torque of the electric motor (11). The invention further relates to a brake system for a vehicle, comprising such a brake actuator (1).

Inventors

• A mine-laying Sai Er
• Herve B.

Assignees

• 罗伯特·博世有限公司

Dates

Publication Date

20260505

Application Date

20240930

Priority Date

20231010

Claims (10)

1. 1. A method (S) for identifying dynamic impacts of an electric brake actuator (1), comprising the steps of: The stiffness of the electric brake actuator (1) is changed based on the motor shaft torque identification (S1) of the motor (11) of the electric brake actuator (1).
2. 2. The method (S) according to claim 1, wherein, upon recognizing (S1) the stiffness change, a ratio of the motor shaft torque to a measured rotational speed of the motor (11) is compared (S1 a) with a predetermined limit value.
3. 3. A method (S) according to claim 2, wherein the predetermined limit value corresponds to a ratio of a maximum activated air gap motor torque to a measured rotational speed of the motor (11).
4. 4. The method (S) according to claim 1, wherein the temporal gradient of the motor shaft moment is compared (S1 b) with a predetermined threshold upon recognizing (S1) the stiffness change.
5. 5. The method (S) according to claim 1, wherein the physical surrogate model parameters of the second order spring mass system are estimated (S1 c) continuously in time upon recognizing (S1) the stiffness change.
6. 6. Method (S) according to claim 5, wherein the physical surrogate model parameters are estimated by means of a "recursive least squares method", which determines the surrogate model parameters, in particular the stiffness, from measured system states.
7. 7. The method (S) according to any of the preceding claims, further comprising the step of decelerating (S2) the motor (11) in accordance with the identified stiffness change.
8. 8. A brake actuator (1) for a brake system of a vehicle, having: an electric motor (11) for delivering a brake fluid, and And a control device configured to recognize a change in stiffness of the brake actuator (1) based on a motor shaft torque of the motor (11).
9. 9. Brake actuator (1) according to claim 8, configured for carrying out the method (S) according to any one of claims 1 to 7.
10. 10. A brake system for a vehicle having a brake actuator (1) according to claim 8 or 9.

Description

Method for detecting dynamic impacts of an electric brake actuator, brake actuator for a brake system, and brake system for a vehicle Technical Field The invention relates to a method for detecting dynamic impacts of an electric brake actuator. The invention further relates to a brake actuator for a brake system of a vehicle. The invention also relates to a brake system for a vehicle, which brake system has such a brake actuator. Background For example, load peaks can occur in the brake actuator if the brake system is hardened or if the brake system is pressed into the rear stop in an uncontrolled manner in the standby state. In this case, in the first case, in particular in the case of ABS control, a large change in the stiffness of the brake system or of the brake actuator is caused by closing the valve. In the case of rapid braking, there is a high rotational speed in the drive train of the brake actuator. Thus, kinetic energy from the rotation of the drive train acts on the suddenly hardened braking system, thereby creating a load spike. Such load peaks should be avoided. In the prior art, some software-based or hardware-based protection measures for brake actuators are known. Disclosure of Invention The invention provides a method for detecting dynamic impacts of an electric brake actuator having the features of claim 1, a brake actuator for a brake system of a vehicle having the features of claim 8, and a brake system for a vehicle having the features of claim 10. According to a first aspect of the invention, a method for detecting dynamic impacts of an electric brake actuator is provided. The method includes the step of identifying a change in stiffness of the electric brake actuator based on a motor shaft torque of a motor of the electric brake actuator. According to a second aspect of the invention, a brake actuator for a brake system of a vehicle is provided. The brake actuator has an electric motor for delivering brake fluid and a control device. The control device is configured to identify a change in stiffness of the brake actuator based on a motor shaft torque of the motor. According to a third aspect of the present invention, a brake system for a vehicle is provided, the brake system having a brake actuator according to the second aspect of the present invention. The invention is based on the idea of protecting the drive train of an electric brake actuator, in particular the electric motor, by optimally controlling the electric motor, against loads critical for the components that may lead to damage to the drive train. In this case, in particular, the mechanical loads occurring in dynamic impacts are reduced. In a dynamic impact, the motor shaft torque increases rapidly. The motor shaft torque is determined in particular by the active drive of the motor and the kinetic energy to be reduced in the event of a dynamic impact. If the brake actuator is hardened by closing all the inlet valves of the wheels of the vehicle and the brake actuator continues to move forward, or if the brake actuator unintentionally moves into the front stop, dynamic shocks in the brake actuator may occur in the forward movement on the one hand. If the brake system is pressed or moved into the rear stop in an uncontrolled manner or actively and unintentionally as a result of incorrect actuation in the standby state, dynamic impacts on the other hand can occur in the backward movement. An advantage of the present invention is that a signal without significant time delay can be used to identify stiffness changes. The motor shaft torque is available as a software variable substantially without delay in order to detect a change in stiffness more quickly, in particular with respect to the signal of an ESP, a pressure sensor or a valve circuit having a delay time of approximately 5 to 20 ms. The load reduction may be significantly improved compared to longer delay times in an ESP, pressure sensor or valve circuit. A further advantage of the invention is a higher accuracy of the determination of the load state, since the measurement is performed directly at the highest load or where the load is formed, i.e. on the motor shaft. Thus, a change in the efficiency of the transmission of the brake actuator can be compensated, wherein, despite the large loads occurring on the motor shaft, low loads may be indicated on the transmission output. Within the meaning of the present invention, a signal is substantially delay-free if it has a delay time of about 1 millisecond or less, in particular a delay time of about 0.5 millisecond. Advantageous embodiments and improvements result from the further dependent claims and the description with reference to the drawings. According to a further development of the invention, the ratio of the motor shaft torque to the measured rotational speed of the motor is compared with a predetermined limit value when a change in stiffness is detected. In particular, the stiffness change is detected when a pr