KR-20260065291-A - BRAKE SYSTEM AND METHOD FOR DETECTING OF PEDAL TRAVEL SENSOR FAILURE OF BRAKE SYSTEM

KR20260065291AKR 20260065291 AKR20260065291 AKR 20260065291AKR-20260065291-A

Abstract

A brake system comprises at least one pedal displacement sensor for detecting displacement of a brake pedal; and a controller electrically connected to the at least one pedal displacement sensor, wherein the controller acquires a pedal displacement value based on receiving an output signal of the at least one pedal displacement sensor, and determines that the at least one pedal displacement sensor is faulty based on the fact that, during the acquisition of the pedal displacement value, the difference between a first pedal displacement value and a second pedal displacement value acquired consecutively is greater than a predetermined reference value, and that at least one pedal displacement value acquired consecutively after the acquisition of the second pedal displacement value is equal to the second pedal displacement value.

Inventors

이찬희

Assignees

에이치엘만도 주식회사

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (20)

At least one pedal displacement sensor for detecting displacement of a brake pedal; and It includes a controller electrically connected to at least one pedal displacement sensor, and The above controller is, A pedal displacement value is obtained based on the reception of the output signal of at least one pedal displacement sensor, and Determining that the at least one pedal displacement sensor is faulty based on the fact that, during the acquisition of the above pedal displacement values, the difference between the first pedal displacement value and the second pedal displacement value acquired consecutively is greater than a predetermined reference value, and that at least one pedal displacement value acquired consecutively after the acquisition of the second pedal displacement value is the same as the second pedal displacement value. Brake system.
In paragraph 1, The above controller is, Acquiring the pedal displacement value based on receiving the output signal of the at least one pedal displacement sensor at each predetermined time period, Brake system.
In paragraph 2, The above controller is, Based on the fact that each of at least one pedal displacement value obtained consecutively after the acquisition of the second pedal displacement value is identical to the pedal displacement value of the immediately preceding time period, the error count value is increased, and Determining that the at least one pedal displacement sensor is faulty based on the fact that the above increased error count value is greater than a preset reference error count, Brake system.
In paragraph 3, The above controller is, In a second period following the first period in which the second pedal displacement value was obtained, the difference value and the predetermined reference value are compared based on the acquisition of the second pedal displacement value. Based on the fact that the above difference value is greater than the above preset reference value, a flag indicating an abnormal state of the at least one pedal displacement sensor is changed to a set state, and the error count is set to 0. Brake system.
In paragraph 3, The above controller is, Based further on the fact that the above flag is in a set state, increasing the above error count value, Brake system.
In paragraph 5, The above controller is, If, while the above increased error count value is less than or equal to the above preset reference error count, at least one pedal displacement value obtained consecutively after the acquisition of the second pedal displacement value is different from the pedal displacement value of the immediately preceding time cycle or if the flag is not set, the at least one pedal displacement sensor is determined to be normal. Brake system.
In paragraph 6, The above controller is, If, while the increased error count value is less than or equal to the preset reference error count, at least one pedal displacement value acquired consecutively after the acquisition of the second pedal displacement value is different from the pedal displacement value of the immediately preceding time cycle, or if the flag is not set, the flag is reset and the error count is set to 0. Brake system.
In paragraph 6, The above controller is, If the difference value is less than or equal to the preset reference value, the at least one pedal displacement sensor is determined to be normal. Brake system.
In paragraph 8, The above at least one pedal displacement sensor is, It includes a first pedal displacement sensor, a second pedal displacement sensor, and a third pedal displacement sensor, The above controller is, If it is determined that the first pedal displacement sensor, the second pedal displacement sensor, and the third pedal displacement sensor are normal, additional fault diagnosis of the first pedal displacement sensor, the second pedal displacement sensor, and the third pedal displacement sensor is performed based on a comparison of the pedal displacement value of the first pedal displacement sensor, the pedal displacement value of the second pedal displacement sensor, and the pedal displacement value of the third pedal displacement sensor. Brake system.
In Paragraph 9, The above controller is, Determining that the third pedal displacement sensor is faulty based on the fact that the difference between the pedal displacement value of the first pedal displacement sensor and the pedal displacement value of the second pedal displacement sensor is less than or equal to a predetermined reference difference value, and the difference between the pedal displacement value of the first pedal displacement sensor and the pedal displacement value of the second pedal displacement sensor, respectively, and the pedal displacement value of the third pedal displacement sensor is greater than a predetermined reference difference value. Brake system.
Acquiring a pedal displacement value based on receiving an output signal from at least one pedal displacement sensor that detects displacement of the brake pedal; Determining that the at least one pedal displacement sensor is faulty based on the fact that, during the acquisition of the pedal displacement value, the difference between the first pedal displacement value and the second pedal displacement value acquired consecutively is greater than a predetermined reference value, and that at least one pedal displacement value acquired consecutively after the acquisition of the second pedal displacement value is the same as the second pedal displacement value. Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 11, Acquiring a pedal displacement value based on receiving an output signal of at least one pedal displacement sensor is, Performed at predetermined time intervals, Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 12, It further includes increasing an error count value based on the fact that each of at least one pedal displacement value obtained consecutively after the acquisition of the second pedal displacement value is identical to the pedal displacement value of the immediately preceding time period. Determining that the above-mentioned at least one pedal displacement sensor is faulty is, Based on the fact that the above increased error count value is greater than a pre-specified standard error count, Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 13, In a second period following the first period in which the second pedal displacement value was obtained, the difference value and the predetermined reference value are compared based on the acquisition of the second pedal displacement value. Based on the fact that the difference value is greater than the preset reference value, the method further comprises changing a flag indicating an abnormal state of the at least one pedal displacement sensor to a set state and setting the error count to 0. Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 13, Increasing the above error count value is, Based further on the fact that the above flag is in a set state, Method for detecting pedal displacement sensor failure in a brake system.
In paragraph 15, The method further comprises determining that the at least one pedal displacement sensor is normal if, while the increased error count value is less than or equal to the preset reference error count, at least one pedal displacement value acquired consecutively after the acquisition of the second pedal displacement value is different from the pedal displacement value of the immediately preceding time cycle or if the flag is in an unset state. Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 16, The method further comprises, while the increased error count value is less than or equal to the preset reference error count, if at least one pedal displacement value obtained consecutively after the acquisition of the second pedal displacement value is different from the pedal displacement value of the immediately preceding time cycle or if the flag is not set, resetting the flag and setting the error count to 0. Method for detecting pedal displacement sensor failure in a brake system.
The method further includes determining that the at least one pedal displacement sensor is normal when the difference value is less than or equal to the preset reference value. Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 18, The above at least one pedal displacement sensor is, It includes a first pedal displacement sensor, a second pedal displacement sensor, and a third pedal displacement sensor, The above pedal displacement sensor failure detection method is, If it is determined that the first pedal displacement sensor, the second pedal displacement sensor, and the third pedal displacement sensor are normal, the method further includes performing additional fault diagnosis of the first pedal displacement sensor, the second pedal displacement sensor, and the third pedal displacement sensor based on a comparison of the pedal displacement value of the first pedal displacement sensor, the pedal displacement value of the second pedal displacement sensor, and the pedal displacement value of the third pedal displacement sensor. Method for detecting pedal displacement sensor failure in a brake system.
In Paragraph 19, Performing the above additional fault diagnosis is, Determining that the third pedal displacement sensor is faulty based on the fact that the difference between the pedal displacement value of the first pedal displacement sensor and the pedal displacement value of the second pedal displacement sensor is less than or equal to a predetermined reference difference value, and the difference between the pedal displacement value of the first pedal displacement sensor and the pedal displacement value of the second pedal displacement sensor, respectively, and the pedal displacement value of the third pedal displacement sensor is greater than a predetermined reference difference value. Method for detecting pedal displacement sensor failure in a brake system.

Description

Brake System and Method for Detecting Pedal Travel Sensor Failure of Brake System The disclosed invention relates to a brake system and a method for detecting failure of a pedal displacement sensor of a brake system. The brake pedal is a device that controls the braking of a vehicle according to the driver's intention to brake. When the displacement of the brake pedal is detected by a pedal displacement sensor installed on the brake pedal, the corresponding signal is transmitted to the brake system, which can then utilize it for braking control of the vehicle. However, there has been a problem where, in the event of a failure of the pedal displacement sensor for the brake pedal, the brake system is unable to perform normal braking control of the vehicle even if the driver presses the brake pedal, due to abnormal signal output or no signal output from the pedal displacement sensor. Accordingly, a technology has been developed to provide redundancy of pedal displacement sensors by providing multiple pedal displacement sensors on the brake pedal. Depending on the type of vehicle, the number of channels for the pedal displacement sensors for the brake pedal is varied, such as 2 channels or 3 channels, so that signals from different channel displacement sensors can be provided to the brake system for each channel. However, conventionally, when the number of channels of the pedal displacement sensor for the brake pedal is 3 channels, there has been a problem in that when a fault injection is performed on two pedal displacement sensors with the same pedal stroke, one normal pedal displacement sensor is determined to be faulty, and the two pedal displacement sensors that received the fault injection are determined to be normal. An external pedal displacement sensor can be connected to a brake system controller (e.g., an Electronic Control Unit (ECU)) via a hard wire, and by manipulating the hard wire in the middle, a distorted signal can be input to the pedal displacement sensor in the same format as the output signal characteristics of the pedal displacement sensor when the signal is distorted. Furthermore, assuming the pedal displacement sensor outputs a signal via the SENT (Single Edge Nibble Transmission) protocol, the SENT protocol is a publicly available protocol that can be hacked by malicious users, potentially allowing for the injection of defects into the pedal displacement sensor. Therefore, when three pedal displacement sensors are provided on the brake pedal, there is a need to develop a new technology that can resolve the problem of determining two pedal displacement sensors with injected defects as normal and determining one pedal displacement sensor that is actually normal as faulty. FIG. 1 is a block diagram showing a part of the configuration of a brake system according to one embodiment. FIG. 2 is a diagram showing the arrangement and electrical connection of each pedal displacement sensor of a brake system according to one embodiment. FIG. 3 is a diagram showing the output signal of a pedal displacement sensor for a brake pedal according to one embodiment. FIG. 4 is a flowchart illustrating the fault diagnosis operation of a pedal displacement sensor of a brake system according to one embodiment. FIG. 5 is a flowchart illustrating the fault diagnosis operation of a pedal displacement sensor of a brake system according to one embodiment. FIG. 6 is a flowchart illustrating the fault diagnosis operation of a pedal displacement sensor of a brake system according to one embodiment. FIG. 7 is a diagram showing the output signals of a first pedal displacement sensor and a second pedal displacement sensor with a defect injected according to one embodiment, and a third pedal displacement sensor operating normally. Throughout the specification, the same reference numerals refer to the same components. This specification does not describe all elements of the embodiments, and general content in the art to which the disclosed invention pertains or content that overlaps between embodiments is omitted. The terms 'part, module, component, block' used in the specification may be implemented in software or hardware, and depending on the embodiments, a plurality of 'parts, modules, components, blocks' may be implemented as a single component, or a single 'part, module, component, block' may include a plurality of components. Throughout the specification, when a part is described as being 'connected' to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected, and indirect connections include connections made via a wireless communication network. Furthermore, when it is stated that a part 'includes' a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Throughout the specification, when it is stated that a component is located 'on' another component