CN107462423B

CN107462423B - Method and device for detecting position of brake pedal

Info

Publication number: CN107462423B
Application number: CN201610396634.2A
Authority: CN
Inventors: 赵毅; 仇林至; 吴平友; 周三国; 赵海燕
Original assignee: SAIC Motor Corp Ltd
Current assignee: SAIC Motor Corp Ltd
Priority date: 2016-06-06
Filing date: 2016-06-06
Publication date: 2020-01-31
Anticipated expiration: 2036-06-06
Also published as: CN107462423A

Abstract

A method and a device for detecting the position of a brake pedal, the method comprises the steps of obtaining a zero position voltage U0 of the brake pedal, detecting the output voltage Ub of a brake pedal sensor corresponding to zero braking force of the brake pedal, judging whether to update the zero position voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to zero braking force of the brake pedal and the zero position voltage U0, and detecting the position of the brake pedal according to the relation between the current output voltage U of the brake pedal sensor, the updated zero position voltage U0 and the maximum output voltage UF when the zero position voltage U0 is determined to be updated, wherein the maximum output voltage UF is the output voltage of the brake pedal sensor corresponding to the maximum stroke of the brake pedal.

Description

Method and device for detecting position of brake pedal

Technical Field

The invention relates to the field of vehicle design, in particular to a method and a device for detecting brake pedal positions.

Background

Since the output voltage of the brake pedal sensor continuously varies within as the brake pedal continuously varies within its designed effective stroke range, the detection of the brake pedal position is achieved by detecting the current position voltage of the brake pedal sensor corresponding to the brake pedal.

At present, when the whole vehicle is off-line detected, an electronic controller receives a command sent by a diagnosis device, and triggers and detects the voltage when a brake pedal is in a free state, and the voltage is stored as the zero voltage of the position of the brake pedal. When the position of the brake pedal is judged, the judgment needs to be carried out according to the zero voltage and the current position voltage of the brake pedal sensor.

However, the detection of the position of the brake pedal by the above-described method may cause inaccurate detection of the position of the brake pedal, thereby deteriorating safety of the vehicle.

Disclosure of Invention

The invention solves the problem of how to improve the accuracy of the detection of the position of the brake pedal so as to improve the safety of the vehicle.

In order to solve the problems, the invention provides a method for detecting the position of a brake pedal, which comprises the steps of obtaining a zero-position voltage U0 of the brake pedal, wherein the zero-position voltage U0 is a reference voltage for calculating the position of the brake pedal, detecting the output voltage Ub of a brake pedal sensor corresponding to zero braking force applied to the brake pedal, judging whether to update the zero-position voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to zero braking force applied to the brake pedal and the zero-position voltage U0, and detecting the position of the brake pedal according to the relation between the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF when the zero-position voltage U0 is determined to be updated, wherein the maximum output voltage UF is the output voltage of the brake pedal sensor corresponding to the maximum stroke of the brake pedal.

Optionally, the obtaining of the zero voltage U0 of the brake pedal includes: and when the brake pedal assembly is assembled, detecting the output voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero, wherein the output voltage is used as the zero voltage U0.

Optionally, the brake pedal assembly is assembled, including any of off-line testing of a vehicle on which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the device for brake pedal position detection.

Optionally, after the brake pedal assembly is assembled and before the detected output voltage of the brake pedal sensor corresponding to zero braking force applied to the brake pedal is detected and is used as the zero voltage U0, the method further comprises the step of determining that the output voltage meets at least conditions that the driving mileage of the vehicle is a valid number, is less than or equal to a preset mileage and belongs to a preset voltage range, and the driving mileage of the vehicle is a valid number, is greater than the preset mileage and belongs to a preset second voltage range.

Optionally, the judging whether to update the zero-position voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to the zero-position voltage U0 when the braking force applied to the brake pedal is zero includes detecting the output voltage Ub of the brake pedal sensor corresponding to the zero-position voltage U0, obtaining an average value Uc of the output voltage Ub meeting a -th storage condition when the output voltage Ub meets a preset -th storage condition and continues for a preset -th threshold, determining to update the zero-position voltage U0 when the average value Uc meets a preset second storage condition and continues for a preset second threshold, and obtaining an average value of the average value Uc meeting the second storage condition as the updated zero-position voltage U0.

Optionally, the obtaining of the average value Uc of the output voltage Ub meeting the 0 storage condition when the output voltage Ub meets the preset storage condition for the preset time threshold includes storing the output voltage Ub and adding to a counter when the output voltage Ub meets the storage condition, obtaining the stored average value Uc of the output voltage Ub of the time threshold until the counter is continuously increased and equal to the preset time threshold, and clearing the counter when an absolute value of a difference between the average value Uc of the output voltage Ub and the zero voltage U0 is smaller than the preset difference threshold, and re-executing the step of detecting the output voltage Ub of the brake pedal sensor corresponding to the brake pedal with zero braking force.

Optionally, the storage condition is any condition, wherein the driving distance of the vehicle is valid data, is less than or equal to a preset distance and the output voltage belongs to a preset voltage range, and the driving distance of the vehicle is valid data, is greater than the preset distance and the voltage belongs to a preset second voltage range.

Optionally, determining whether the Uc satisfies a predetermined second storage condition for a predetermined second secondary threshold value, includes determining whether a second counter is zero when an absolute value of a difference between the average value Uc of the output voltage Ub and the zero-bit voltage U0 is greater than or equal to the th difference threshold value, recording the average value Uc of the output voltage as the th output voltage average value Uc1 and adding to the second counter when the second counter is zero, determining whether an absolute value of a difference between the average value Uc of the secondary output voltage and the reference output voltage average value UcA is less than or equal to a predetermined second difference threshold value when the second counter is i and i is not zero, wherein the reference output voltage average value UcA is an average value of the previous i output voltage average values Uc, when an absolute value of a difference between the average value Uc of the output voltage and the reference output voltage average value UcA is greater than the second difference threshold value, storing all of the output voltage average values Uc 2-Uc and the absolute value nt + t of the second counter as the second difference threshold value ndza + t, determining whether the absolute value of the average value of the output voltage nc is equal to the second threshold value ndt + t, and the second counter when the absolute value of the second counter is greater than the second threshold value, and the predetermined second counter, and the second counter is equal to the second threshold value, and the second threshold value of the second counter is equal to the second threshold value of the output voltage average value 3623, and the output voltage average value.

Optionally, the second storage condition is: the absolute value of the difference between the average value Uc of the output voltage at the current time and the reference output voltage average value UcA is less than or equal to the second difference threshold.

The embodiment of the invention provides an method for detecting the position of a brake pedal, which comprises the steps of obtaining an input voltage corresponding to a zero-position voltage U0 of the brake pedal, calculating the ratio of the zero-position voltage U0 to the input voltage as a zero-position voltage ratio P0, calculating the reference voltage ratio of the position of the brake pedal by the zero-position voltage ratio P0, calculating the ratio of the current output voltage U to the input voltage corresponding to the current output voltage U as a current output voltage ratio P, and detecting the position of the brake pedal according to the relation among the current output voltage ratio P, the zero-position voltage ratio P0 and the maximum output voltage ratio PF, wherein the maximum output voltage ratio PF is the ratio of the maximum output voltage UF to the input voltage corresponding to the maximum output voltage UF.

Optionally, the method further comprises: calculating the ratio Pb of the output voltage Ub to the input voltage corresponding to the output voltage Ub; judging whether to update the zero voltage ratio P0 according to the relation between the ratio Pb of the input voltage and the zero voltage ratio P0; when the zero voltage ratio P0 is determined to be updated, the position of the brake pedal is detected according to the relation among the current output voltage P of the brake pedal sensor, the updated zero voltage ratio P0 and the maximum output voltage ratio PF.

Optionally, the calculating a ratio of the zero voltage U0 and the input voltage as a zero voltage ratio P0 includes: after the brake pedal assembly is assembled, detecting the output voltage and the input voltage of a corresponding brake pedal sensor when the braking force applied to the brake pedal is zero, and taking the ratio of the output voltage and the input voltage as a zero-position voltage ratio P0.

Optionally, after the brake pedal assembly is assembled, before the output voltage and the input voltage of the brake pedal sensor corresponding to the brake pedal with zero braking force are detected, the ratio of the output voltage to the input voltage is used as a zero-position voltage ratio P0, the method further comprises the step of determining that the ratio of the output voltage to the input voltage meets at least conditions that the driving mileage of the vehicle is an effective number and less than or equal to a preset mileage, the ratio of the output voltage to the input voltage belongs to a preset -th voltage ratio range, the driving mileage of the vehicle is an effective number and more than the preset mileage, and the ratio of the output voltage to the input voltage belongs to a preset second voltage ratio range.

Optionally, the determining whether to update the zero voltage ratio P0 according to the relationship between the ratio Pb of the input voltage and the zero voltage ratio P0 includes: detecting the ratio Pb of the output voltage and the input voltage of a brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero; when the ratio Pb meets a preset third storage condition and continuously reaches a preset third time threshold value, calculating an average value Pc of the voltage ratio Pb meeting the third storage condition; and when the Pc meets a preset fourth storage condition and continuously reaches a preset fourth number threshold, determining to update the zero voltage ratio P0, and solving the average value of the Pc meeting the fourth storage condition as an updated zero voltage ratio P0.

Optionally, the step of obtaining the average value Pc of the voltage ratio Pb meeting the third storage condition when the ratio Pb meets the preset third storage condition and continuously reaches the preset third time threshold includes detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the brake pedal receiving zero braking force, storing the ratio Pb of the voltage and adding a third counter when the ratio Pb of the voltage meets the third storage condition, obtaining the average value Pc of the stored ratio Pb of the preset third time threshold until the third counter continuously increases and equals to the preset third time threshold, and when the absolute value of the difference between the average value Pc and the zero voltage ratio P0 is smaller than the preset third difference threshold, resetting the third counter and re-executing the step of detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the brake pedal receiving zero braking force.

Optionally, the third storage condition is any of the following conditions that the driving distance of the vehicle is valid data, is less than or equal to a preset distance and the voltage ratio belongs to a preset voltage ratio range, and the driving distance of the vehicle is valid data, is greater than the preset distance and the voltage ratio belongs to a preset second voltage ratio range.

Optionally, the determining whether the Pc meets a preset fourth storage condition includes determining whether a fourth counter is zero when an absolute value of a difference between the average Pc of the voltage ratios and the zero-voltage ratio P0 is greater than or equal to the third difference threshold, recording the average Pc of the voltage ratios as a th output voltage ratio average Pc1 and adding to the fourth counter when the fourth counter is zero, determining whether an absolute value of a difference between the average Pc of the voltage ratios and a reference voltage ratio average PcA is less than or equal to a preset fourth difference threshold when the fourth counter is i, determining whether all of the average Pc of the voltage ratios are 1-Pc (i) and the fourth counter is zero when the absolute value of a difference between the average Pc of the voltage ratios and the reference voltage ratio average PcA is greater than the fourth difference threshold, determining whether the absolute value of the difference between the average Pc of the voltage ratios and the reference voltage ratio average Pc of the fourth counter is equal to the fourth difference threshold, and determining whether the absolute value of the difference between the average Pc of the voltage ratios and the reference voltage ratio average Pc of the fourth counter is equal to the preset fourth difference threshold 3668 + kdi when the absolute value of the average Pc of the voltage ratios and the fourth counter is greater than the preset fourth difference threshold, determining whether the absolute value of the fourth counter is equal to the fourth difference threshold, and determining whether the absolute value of the fourth counter is equal to the fourth difference threshold + kdi, wherein the fourth counter 361.

Optionally, the fourth storage condition is: the absolute value of the difference between the average value Pc of the voltage ratio of the current time and the average value PcA of the reference voltage ratio is less than or equal to the fourth difference threshold.

The embodiment of the invention provides an brake pedal position detection device which comprises a acquisition unit, a judgment unit and a position detection unit, wherein the acquisition unit is suitable for acquiring a zero-position voltage U0 of a brake pedal, the zero-position voltage U0 is a reference voltage for calculating the position of the brake pedal, the detection unit is suitable for detecting the output voltage Ub of a brake pedal sensor corresponding to zero braking force applied to the brake pedal, the judgment unit is suitable for judging whether the zero-position voltage U0 is updated according to the relation between the output voltage Ub of the brake pedal sensor corresponding to zero braking force applied to the brake pedal and the zero-position voltage U0, the position detection unit is suitable for detecting the position of the brake pedal according to the relation among the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and a maximum output voltage UF when the judgment unit determines that the zero-position voltage U0 is updated, and the maximum output voltage UF of the brake pedal is corresponding to the maximum stroke.

Optionally, the th acquisition unit comprises a th detection subunit and a th voltage selection subunit, wherein the th detection subunit is suitable for detecting the output voltage of a brake pedal sensor corresponding to zero braking force applied to the brake pedal after the brake pedal assembly is assembled, and the th voltage selection subunit is suitable for enabling the output voltage detected by the th detection subunit to serve as the zero voltage U0.

Optionally, the obtaining unit further comprises a determining subunit adapted to determine whether at least conditions that the vehicle has a driving range of a valid number and is less than or equal to a preset range and the output voltage belongs to a preset voltage range, that the vehicle has a driving range of a valid number and is greater than the preset range and the output voltage belongs to a preset second voltage range are met after the detecting subunit detects the output voltage, and the voltage selecting subunit is further adapted to use the output voltage detected by the detecting subunit as the zero voltage U0 when the determining subunit determines that the output voltage meets the at least conditions.

Optionally, the th judging unit includes a second detecting subunit adapted to detect the output voltage Ub of the brake pedal sensor corresponding to zero braking force applied to the brake pedal, a th calculating subunit adapted to obtain an average value Uc of the output voltage Ub meeting a th storage condition when the output voltage Ub meeting a preset th storage condition continues for a preset th threshold, and a th updating subunit adapted to determine to update the zero voltage U0 and obtain the average value of the Uc meeting the second storage condition as an updated zero voltage U0 when the Uc meets a preset second storage condition continues for a preset second threshold.

Optionally, the th calculation subunit includes a th storage module adapted to store the output voltage Ub when the output voltage Ub meets the 0 th storage condition, a 1 th counter adapted to calculate the number of the output voltages Ub stored in the 2 th storage module, a 3 th calculation module adapted to obtain an average Uc of the output voltage Ub of the th threshold when the th counter is continuously increased and equal to a preset th threshold, a th judgment module adapted to judge whether an absolute value of a difference between the average Uc and the zero-position voltage U0 is smaller than a preset th difference threshold, and a th control module adapted to zero the th counter when the absolute value of the difference between the average Uc and the zero-position voltage U0 is smaller than the th difference threshold, and control the second detection unit to perform the step of detecting the output voltage Ub of the brake pedal corresponding to the brake pedal when the brake pedal is subjected to zero.

Optionally, the storage condition is any condition, wherein the driving distance of the vehicle is valid data, is less than or equal to a preset distance and the output voltage belongs to a preset voltage ratio range, and the driving distance of the vehicle is valid data, is greater than the preset distance and the output voltage belongs to a preset second voltage ratio range.

Optionally, the updating subunit comprises a second determining module adapted to determine whether a second counter is zero when determining that the absolute value of the difference between the average value Uc of the output voltage and the zero-bit voltage U0 is greater than or equal to the difference threshold, a recording module adapted to record the average value Uc of the output voltage when the second counter is zero, and use the recorded average value Uc of the output voltage as the average value Uc1, a second counter adapted to record the number of the average values Uc of the output voltage, a third determining module adapted to determine whether the absolute value of the difference between the average value Uc of the output voltage and the reference average value UcA is less than or equal to a preset second difference threshold when determining that the second counter is i and i is not zero, wherein the reference average value UcA is the average value of the previous i average values Uc of the output voltages, a second control module adapted to store the absolute value of the second counter equals to the preset second difference value Uc when determining that the absolute value Uc of the average value Uc of the output voltage is greater than or equal to the preset second threshold, and a fourth determining module adapted to store the absolute value ndza + t + the second counter when determining that the absolute value of the average value Uc is greater than the preset second counter, and i + t +.

The embodiment of the invention provides brake pedal position detection device, which comprises a second acquisition unit, a calculation unit, a second calculation unit and a second position detection unit, wherein the second acquisition unit is suitable for acquiring input voltage corresponding to zero voltage U0 of a brake pedal, the calculation unit is suitable for calculating the ratio of the zero voltage U0 to the input voltage as a zero voltage ratio P0, the zero voltage ratio P0 is a reference voltage ratio for calculating the position of the brake pedal, the second calculation unit is suitable for calculating the ratio of the current output voltage U to the input voltage corresponding to the current output voltage U as a current output voltage ratio P, and the second position detection unit is suitable for detecting the position of the brake pedal according to the relation among the current output voltage P, the zero voltage ratio P0 and a maximum output voltage ratio PF, wherein the maximum output voltage ratio is the ratio of the maximum output voltage PF to the input voltage corresponding to UF.

Optionally, the apparatus further comprises: a third calculating unit, adapted to calculate a ratio Pb of the output voltage Ub to an input voltage corresponding to the output voltage Ub; the second judging unit is suitable for judging whether to update the zero voltage ratio P0 according to the relation between the ratio Pb of the input voltage and the zero voltage ratio P0; the second position detection unit is further adapted to detect the position of the brake pedal according to a relationship among the current output voltage P of the brake pedal sensor, the updated zero-position voltage ratio P0, and the maximum output voltage ratio PF when the second determination unit determines that the zero-position voltage ratio P0 is updated.

Optionally, the th calculating unit is adapted to detect that the brake pedal is subjected to zero braking force when the brake pedal assembly is assembled, and use the ratio of the output voltage to the input voltage as the zero-position voltage ratio P0, wherein the ratio corresponds to the output voltage to the input voltage of the brake pedal sensor.

Optionally, the pedal assembly is assembled, including any of off-line testing of a vehicle on which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the device for brake pedal position detection.

Optionally, the device further comprises a third judging unit, which is adapted to determine that the ratio of the output voltage to the input voltage meets at least conditions that the driving mileage of the vehicle is a valid number and less than or equal to a preset mileage, and the ratio of the output voltage to the input voltage belongs to a preset voltage ratio range, and the driving mileage of the vehicle is a valid number and more than or equal to a preset mileage, and the ratio of the output voltage to the input voltage belongs to a preset second voltage ratio range after the brake pedal assembly is assembled and after the ratio of the output voltage to the input voltage of the brake pedal sensor corresponding to the brake pedal subjected to zero braking force is detected as a zero-position voltage ratio P0.

Optionally, the second determining unit includes: the third detection subunit is suitable for detecting the ratio Pb of the output voltage and the input voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero; the second calculating subunit is suitable for calculating an average value Pc of the voltage ratio Pb meeting the third storage condition when the ratio Pb meets the preset third storage condition and continuously reaches a preset third time threshold; and the second updating subunit is suitable for determining to update the null voltage ratio P0 when the Pc meets a preset fourth storage condition and continuously reaches a preset fourth number threshold, and solving the average value of the Pc meeting the fourth storage condition as an updated null voltage ratio P0.

Optionally, the second computing subunit includes: the second detection module is suitable for detecting the ratio Pb of the output voltage and the input voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero; the second storage module is suitable for storing the ratio Pb of the voltages when the ratio Pb of the voltages meets the third storage condition; the third counter is suitable for recording the number of the ratio Pb in the second storage module; the second calculation module is suitable for calculating the average value Pc of the ratio Pb of the stored preset third-time threshold voltage until the third counter is continuously increased and equal to the preset third-time threshold value; a fifth judging module, adapted to judge whether an absolute value of a difference between the average value Pc and the zero voltage ratio P0 is smaller than a preset third difference threshold; and the fourth control module is suitable for resetting the third counter when the absolute value of the difference value between the average value Pc and the zero-position voltage ratio P0 is smaller than the third difference threshold value, and re-executing the step of detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero.

Optionally, the second updating subunit includes a sixth determining module adapted to determine whether a fourth counter is zero when an absolute value of a difference between the average Pc of the voltage ratios and the zero-position voltage ratio P0 is greater than or equal to the third difference threshold, a second recording module adapted to record the average Pc of the voltage ratios as a output voltage ratio average Pc1 when the fourth counter is zero, a fourth counter adapted to calculate the number of the average Pc1 in the second recording module, a seventh determining module adapted to determine whether an absolute value of a difference between the average Pc of the voltage ratios and a reference voltage ratio average PcA is less than or equal to a preset fourth difference threshold when the fourth counter is i and i is not zero, wherein the reference voltage ratio average PcA is an average of the previous i voltage ratio averages, a fifth controlling module adapted to store the absolute value Pc of the average Pc of the voltage ratios and the reference voltage average PcA as a preset fourth difference threshold when the absolute value of the absolute value Pc of the average Pc of the voltage ratios and the reference voltage ratio average 355637 is greater than or less than the preset fourth difference threshold, and determine whether the absolute value of the sum of the fourth counter is equal to the fourth difference value of the sixth counter and the fourth counter, wherein the fourth counter is equal to the fourth counter, and the absolute value of the fourth counter is equal to the fourth counter PcA, and the fourth counter is equal to the fourth counter, and the absolute value of the fifth determining module is equal to the fourth counter.

Compared with the prior art, the technical scheme of the invention has the following advantages:

because the relation between the output voltage Ub of the brake pedal sensor and the zero-position voltage U0 corresponding to the brake pedal when the braking force applied to the brake pedal is zero can reflect the change of the free-state position of the brake pedal caused by aging and the like, in order to avoid the change of the free-state position of the brake pedal caused by aging and the like, whether the zero-position voltage U0 is updated or not can be judged according to the relation between the output voltage Ub and the zero-position voltage U0, and then when the zero-position voltage U0 is determined to be updated, the position of the brake pedal is detected according to the relation between the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF, so that the accuracy of detecting the position of the brake pedal can be improved, and the safety of a vehicle can be improved.

Since the input voltage of the brake pedal sensor affects the output voltage thereof and changes after the vehicle is used, the current output voltage P of the brake pedal sensor and the updated zero-position voltage ratio P are adopted₀And maximum output voltage ratio P_FThe position of the brake pedal is detected, so that errors caused by the change of the input voltage and the detection result of the position of the brake pedal can be avoided, the accuracy of the detection of the position of the brake pedal is further improved , and the safety of the vehicle is improved.

Drawings

FIG. 1 is a schematic flow chart diagram of a method of brake pedal position detection in an embodiment of the present invention;

FIG. 2 is a schematic flow chart diagram illustrating another method of brake pedal position detection in an embodiment of the present invention;

FIG. 3 is a schematic illustration of the operating principle of brake pedal components in an embodiment of the invention;

FIG. 4a is a schematic flow chart of another method of brake pedal position detection in an embodiment of the present invention;

FIG. 4b is a schematic flow chart of another brake pedal position detection method in an embodiment of the present invention;

FIG. 5a is a schematic flow chart of another method of brake pedal position detection in an embodiment of the present invention;

FIG. 5b is a schematic flow chart of another brake pedal position detection method in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of brake pedal position sensing apparatus in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of kinds of judgment units in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of another brake pedal position sensing arrangement in an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of another brake pedal position sensing arrangement in an embodiment of the present invention;

fig. 10 is a schematic structural diagram of types of second judgment units in the embodiment of the invention;

fig. 11 is a schematic structural diagram of another brake pedal position detection apparatus in an embodiment of the present invention.

Detailed Description

When the vehicle is used, along with the continuous aging of the brake pedal and the whole brake system, when the brake pedal is in a free state, the corresponding position is changed compared with the corresponding position when the whole vehicle leaves a factory, and the output voltage value corresponding to the brake pedal in the free state is also changed compared with the corresponding zero voltage value when the whole vehicle leaves the factory.

In order to solve the above problems, embodiments of the present invention provide a method and an apparatus for detecting a position of a brake pedal, where a relationship between an output voltage Ub of a brake pedal sensor and a zero voltage U0, which corresponds to when a braking force applied to the brake pedal is zero, may reflect a change in a free state position of the brake pedal due to aging, and the like, so that the method determines whether to update the zero voltage U0 according to the relationship between the output voltage Ub and the zero voltage U0, and further detects the position of the brake pedal according to a relationship between a current output voltage U of the brake pedal sensor, the updated zero voltage U0, and a maximum output voltage UF when the zero voltage U0 is determined to be updated, thereby improving accuracy of detection of the position of the brake pedal and improving safety of a vehicle.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

A flow chart of a method of brake pedal position detection in an embodiment of the present invention is shown below and described in detail with reference to fig. 1:

s11: and acquiring a zero voltage U0 of the brake pedal.

In the embodiment of the present invention, the zero voltage U0 may be used as a reference voltage to obtain the current position of the brake pedal, as shown in formula (1):

S＝100×(U0-U)/(U0-UF)％-offsetS (1)

wherein: s is a current position of the brake pedal, offsetS is a drift position amount that is allowed to actually occur to the brake pedal during the period of judging whether the zero voltage is updated, a specific value thereof may be obtained through engineering verification and bench test, UF is an output voltage of the brake pedal sensor corresponding to when the brake pedal reaches the maximum stroke, and U is an output voltage corresponding to the current position of the brake pedal.

In order to ensure that the zero voltage U0 corresponds to the current brake pedal structure, in a specific implementation, if the brake pedal assembly is assembled, the output voltage of the brake pedal sensor corresponding to the brake pedal receiving zero braking force can be detected, and the output voltage is taken as the zero voltage U0.

In a specific implementation, the assembly of the brake pedal assembly may include various scenarios, such as an offline test of a vehicle on which the brake pedal is installed, a replacement of the brake pedal sensor, and a replacement of a device responsible for detecting the current position of the brake pedal. It is to be understood that the assembly of the brake pedal assembly does not include only those illustrated herein, but the examples herein are merely for the convenience of those skilled in the art to better understand the present invention and are not to be construed as limiting the present invention in any way.

Since the free-state position of the pedal changes with the difference in mileage of the vehicle, in the embodiment of the present invention, after the brake pedal assembly is assembled, before the detected output voltage of the brake pedal sensor when the braking force applied to the brake pedal is zero is used as the zero voltage U0, it may be determined that the driving range of the vehicle is a valid number, is less than or equal to a preset range and the output voltage belongs to a preset voltage range, or the driving range of the vehicle is a valid number, is greater than the preset range and the output voltage belongs to a preset second voltage range.

S12: and detecting the output voltage Ub of the brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero.

S13: it is determined whether the zero voltage U0 is updated.

It will be appreciated that, throughout the service cycle of the brake pedal, if the position of the brake pedal at which the applied braking force is zero, i.e. the free-state position, is constant, the output voltage Ub of the brake pedal sensor corresponding to the zero position voltage U0 and the zero position voltage U0 should also be the same when the brake pedal is subjected to zero brake force, however, due to aging and the like, as the service life increases, the free state position of the brake pedal actually changes, correspondingly, the voltage output by the brake pedal sensor when the brake pedal is in the free state position is different, if the previous zero voltage U0 is still used as the reference voltage to calculate the current position of the brake pedal after the change of the free-state position of the brake pedal, the obtained position result is inaccurate. Therefore, in specific implementation, whether to update the zero voltage U0 can be determined according to the relationship between the output voltage Ub of the brake pedal sensor and the zero voltage U0 when the braking force applied to the brake pedal is zero.

In a specific implementation, whether the zero-position voltage U0 is updated or not can be judged by continuously detecting the output voltage Ub. of the brake pedal sensor corresponding to the brake pedal receiving zero braking force, and then judging the output voltage Ub, storing the output voltage Ub only when the driving range of the vehicle is an effective number and less than or equal to a preset range and the output voltage belongs to a preset voltage range, or when the driving range of the vehicle is an effective number and more than the preset range and the voltage ratio belongs to a preset second voltage range, adding to an -th counter to record the number of the output voltages Ub meeting the condition, and obtaining an average value of the stored -th threshold number of times of the output voltages Ub when the -th counter is continuously increased and reaches a preset -th threshold of times.

For convenience of illustration, the average value of the output voltage Ub is counted as Uc., and then the average value Uc is determined, if the absolute value of the difference between the average value Uc and the zero-position voltage U0 is smaller than a preset difference threshold, the counter may be cleared, and the step of continuously detecting the output voltage Ub of the brake pedal sensor corresponding to the brake pedal having zero braking force applied thereto may be executed again, is performed until the counter is continuously incremented again and reaches a preset threshold.

If the absolute value of the difference between the average value Uc of the output voltage and the zero voltage U0 is greater than or equal to the difference threshold, it may be determined whether a second counter is zero, and when the second counter is zero, the average value Uc of the output voltage calculated this time may be directly recorded as the average value Uc1 of the output voltage, and is added to the second counter.

If the second counter is i and i is not zero, it may be determined whether the absolute value of the difference between the average value Uc of the output voltage and the reference output voltage average value UcA at this time is less than or equal to a preset second difference threshold, where it is noted that the reference output voltage average value UcA is the average value of the average values of the previous i output voltages, then if the absolute value of the difference between the average value Uc of the output voltage and the reference output voltage average value UcA is greater than the second difference threshold, all of the output voltage average values Uc (1) to Uc (i) and the second counter are set to zero, but if the absolute value of the difference between the average value Uc of the output voltage at this time and the reference output voltage average value UcA is less than the second difference threshold, the second counter may be added, and the average value Uc of the output voltage at this time may be recorded as the i +1 th output voltage average value Uc (i +1), the average value of the i output voltage average values has been obtained previously, and the average value of the second counter is not obtained as the number corresponding to the number of i + 1.

For example, the counter is 3, UcA, which is an average value of three voltages of Uc1, Uc2 and Uc3, if the absolute value of the difference between the average value Uc of the output voltage and the average value UcA of the three voltages of Uc1, Uc2 and Uc3 is greater than the second difference threshold, all the output voltage average values Uc1-Uc3 and the second counter are set to zero, and if the absolute value of the difference between the average value Uc of the output voltage and the reference output voltage average value UcA is less than the second difference threshold, the second counter may be added to become 4, and the average value Uc of the output voltage of this time may be recorded as the 4 th output voltage average value Uc 4.

Then, whether the value i in the second counter is equal to a preset second-time threshold value Ndzat is judged, when the value i in the second counter is equal to the preset second-time threshold value Ndzat, it may be determined that the zero voltage U0 is updated, and finally, an average value Uci of the average values of the preset second-time threshold values Ndzat is obtained as the updated zero voltage U0.

When it is determined to update the zero voltage U0, executing S14; otherwise, the flow is ended.

S14: and detecting the position of the brake pedal according to the relation among the current output voltage U of the brake pedal sensor, the updated zero voltage U0 and the maximum output voltage UF.

In order to avoid inaccuracy of the detection result of the brake pedal position caused by the change of the free-state position of the brake pedal, in a specific implementation, after determining to update the zero-position voltage U0, the formula (2) may be adopted to detect the position of the brake pedal according to the relationship among the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF:

S＝100×(U1-U)/(U1-UF)％-offsetS (2)

wherein: s is the current position of the brake pedal, and U1 is the updated zero voltage U0.

In order to timely find out the short circuit to the ground or the open circuit fault of the relevant component of the brake pedal, in the embodiment of the invention, if the current output voltage U is detected to be less than the preset voltage threshold UGND within the continuous preset time period T, the position signal of the brake pedal sensor can be set to 100%, and the position validity of the brake pedal sensor can be set to be invalid.

In order to timely detect the open-circuit fault of the relevant components of the brake pedal, in the embodiment of the present invention, if the current output voltage U is detected to be greater than the preset second voltage threshold value UBAT within the continuous preset time period T, the position signal of the brake pedal sensor is set to 100%, and the position validity of the brake pedal sensor is set to be invalid.

In order to timely find out the abnormal condition of the output of the brake pedal sensor, in the embodiment of the invention, when the current output voltage U is detected to be less than or equal to the preset second voltage threshold value UBAT and greater than the zero position voltage U0 before updating within the continuous preset time period T, the position signal of the brake pedal sensor may be set to 0%, and the position validity of the brake pedal sensor may be set to be invalid.

In another embodiment of the invention, when the zero voltage U0 is not obtained, the position signal of the brake pedal sensor is set to 100% and the position validity of the brake pedal sensor is set to invalid, thus , when the zero voltage U0 is not detected, i.e., the electronic controller does not receive a diagnosis detection command or detects the zero voltage U0 or fails to detect the zero voltage U0, the fault can be timely discovered and recorded.

Since the output voltage of the brake pedal sensor is affected not only by the structure of the brake pedal related component but also by the input voltage of the brake pedal sensor throughout the entire operating cycle of the brake pedal, the position of the brake pedal may be detected using the method shown in fig. 2 in the embodiment of the present invention, which may include the steps of:

s21: an input voltage corresponding to the zero voltage U0 of the brake pedal is obtained.

S22: the ratio of the zero voltage U0 and the input voltage is calculated as the zero voltage ratio P0.

In order to avoid an error in the detection result of the brake pedal position due to fluctuation of the input voltage of the brake pedal sensor, a ratio of the zero voltage U0 to the input voltage may be calculated as a zero voltage ratio P0, and the zero voltage ratio P0 is a reference voltage ratio for calculating the brake pedal position.

S23: and calculating the ratio of the current output voltage U to the input voltage corresponding to the current output voltage U as the current output voltage ratio P.

S24: and detecting the position of the brake pedal according to the relation among the current output voltage P, the zero voltage ratio P0 and the maximum output voltage ratio PF.

In a specific implementation, the zero voltage ratio P0 can be used to calculate the brake pedal position using equation (3):

S＝100×(P0-P)/(P0-PF)％-offsetS (3)

wherein: s is the current position of the brake pedal, and PF is the ratio of the maximum output voltage UF to the corresponding input voltage.

In another embodiment of the present invention, the ratio Pb of the output voltage Ub to the input voltage corresponding to the output voltage Ub may be calculated, then the ratio Pb of the input voltage is compared with the zero voltage ratio P0, and then whether to update the zero voltage ratio P0 is determined according to the relationship between the ratio Pb of the input voltage and the zero voltage ratio P0, and if it is determined that the zero voltage ratio P0 is updated, the position of the brake pedal may be obtained by using the formula (4) according to the relationship between the current output voltage P of the brake pedal sensor, the updated zero voltage ratio P0, and the maximum output voltage ratio PF:

S＝100×(P1-P)/(P1-PF)％-offsetS (4)

wherein: s is the current position of the brake pedal, and P1 is the updated zero voltage ratio.

To enable those skilled in the art to better understand and implement the present invention, a schematic connection diagram of brake pedal related components in an embodiment of the present invention is shown below, which may include, as shown in fig. 3:

an electronic controller 309, a memory 313 and a diagnostic device 308, wherein a brake pedal position signal 311 is output from the electronic controller 309, and the interface related to the input of the electronic controller 309 can be or more of an ignition key state interface 301, a brake lamp switch state interface 302, an engine working state interface 303, a vehicle mileage state interface 304, a vehicle mileage availability state interface 305, a driver state interface 306 and a vehicle network wake-up state interface 307.

The electronic controller 309 can know whether the whole vehicle is in a power-on state or not through ignition key state information fed back by the ignition key state interface 301, the electronic controller 309 can know whether the brake lamp switch of the whole vehicle is activated or not through judgment of the state of the brake lamp switch, the electronic controller 309 can know whether the engine is in a working state or not through judgment of the working state interface 303 of the engine, the electronic controller 309 can know the current driving range of the whole vehicle through judgment of the driving range state interface 304 of the whole vehicle, the electronic controller 309 can know whether the driving range 304 of the whole vehicle is a real and effective value or not according to judgment of the effectiveness of the driving range 305 of the whole vehicle, the electronic controller 309 can know the opening and closing state of a driver of the whole vehicle through judgment of the network awakening state interface 307 of the whole vehicle, the brake pedal sensor 310 can be a resistance type sensor per se, and the electronic controller 309 can be suitable for supplying power to the brake pedal sensor 310, and voltage output from the brake pedal sensor 310 can be input to the electronic controller 309.

The electronic controller 309 can continuously detect the output voltage value Ub of the brake pedal sensor 310 during the whole operation, the electronic controller 309 can calculate and output a brake pedal position signal 311 and a brake pedal position validity signal 312 according to the output voltage value Ub, when the vehicle is off-line or the whole vehicle is replaced with the brake pedal or the brake pedal sensor 310 or the electronic controller 309, that is, when the components of the brake pedal are reinstalled, a diagnostic command can be sent to the electronic controller 309 through the diagnostic device 308, and after receiving the diagnostic command, the electronic controller 309 can memorize the output voltage value of the initial position of the brake pedal sensor 310 as the zero voltage U0, that is, the reference voltage for calculating the current position of the brake pedal thereafter, and the memory 313 corresponding to the electronic controller 309 can save important variables, such as the zero voltage U0, during the whole detection.

In order to make the present invention more understandable and practical for those skilled in the art, another brake pedal position detection method in the embodiment of the present invention is provided below, and before describing the detection method in detail, the meaning of the relevant parameters under is first described to facilitate the following description:

u0 indicates the output voltage of the initial position of the brake pedal sensor successfully detected by the electronic controller after the diagnostic command is sent to the electronic controller by the diagnostic device, i.e. the zero-position voltage, U1 indicates the updated zero-position voltage value, and the initial value of U1 is identical to U0. Uci (the value of i can be 1, 2, 3, … … Ndzat) indicates that when the brake pedal is in a free state and the brake pedal sensor has significantly deviated from the currently stored zero-position voltage U0 or the updated zero-position voltage U1 value, the electronic controller needs to adjust the average value of the corresponding output voltage Ub value, noted Uci.Ndzat indicates that if the brake pedal sensor has significantly deviated from the currently stored U0 or U1 value for consecutive Ndzat times, the electronic controller needs to adjust the U1 value, the first counter A indicates the initial value is 0. CounterB indicates the initial value is 0. C0.

Uzri represents the output voltage of the brake pedal sensor at the initial stage of its use, when it is in the free-state position. Uzrl represents the output voltage of the brake pedal sensor throughout its life cycle, in its free-state position, and ranges greater than Uzri depending on the braking system characteristics. And the electronic controller determines Uzri and Uzrl according to the driving mileage of the whole vehicle. When the mileage of the whole vehicle is less than or equal to the preset mileage, the electronic controller considers that the brake pedal sensor is in the initial use stage, and the output voltage range of the initial position is Uzri. And when the mileage of the whole vehicle is greater than the preset mileage, the electronic controller considers that the range of the output voltage of the initial position of the brake pedal sensor is Uzll.

UGND represents the range of output voltage Ub values corresponding to the brake pedal sensor output when it is shorted to ground or open to the ground UBAT represents the range of output voltage Ub values corresponding to the brake pedal sensor output when it is shorted to the power source UF represents the value of output voltage Ub corresponding to the brake pedal sensor when the brake pedal reaches a maximum travel, Δ Ua represents the value of output voltage Ub detected by the electronic controller when it determines that the current brake pedal is in a free state that deviates from the maximum allowable range of U0 or U1, and when that range is exceeded indicates that the brake pedal free state position has significantly deviated.

The method is described in detail below with reference to fig. 3, 4a and 4b, and may include the following steps:

s401: it is detected whether there is any malfunction of the brake pedal sensor.

In particular implementations, after the assembly of the relevant components of the brake pedal, the electronic controller may detect the value of the null voltage U0 of the brake pedal sensor and memorize the null voltage U0 in memory. When the whole electronic controller works, the diagnosis equipment needs to send a corresponding diagnosis command to the electronic controller.

After receiving the diagnosis command, the electronic controller detects a Ub value of the brake pedal sensor, if the vehicle mileage is less than or equal to the preset mileage, the vehicle mileage validity is valid, and the Ub value is within the range of the th voltage range Uzli, the current Ub value is stored and memorized in a memory from a U0 storage device, if the vehicle mileage is greater than the preset mileage, the vehicle mileage validity is valid, and the Ub value is within the range of the second voltage range Uzll, the current Ub value is stored and memorized in a memory from a zero-position voltage U0, the value of the initialization voltage parameter U1 is the acquired zero-position voltage U0, and the voltage parameter U1 is an updated zero-position voltage.

In order to timely detect the failure of the brake pedal component, in a specific implementation, whether any failure exists in the brake pedal sensor may be detected, and when no failure exists in the brake pedal sensor, S402 and S419 may be executed, or conversely, S422, S424, S425, S426 and S427 may be executed, and it should be noted that the specific execution sequence of S422, S424, S425, S426 and S427 is not limited to any particular order, and may be executed sequentially, or may be executed in parallel .

S402: initially, CounterA is 0.

In a specific implementation, counter A may be set to zero.

And S403, judging whether the network awakening state is the network awakening source awakening network, changing the state of a driver from off to on, detecting that the whole vehicle is in a power-off state according to the state of the ignition key, and detecting that the brake lamp switch is effective and the brake lamp has no fault.

In a specific implementation, when the wakening status is that the wakening source wakens up the network, the status of the driver changes from off to on, and it is detected that the entire vehicle is in the power-off status according to the status of the ignition key, and the stop lamp switch is active and the stop lamp is not faulty, the electronic controller may determine that the current brake pedal is in the free state, and perform S404, otherwise, continue to perform S402.

S404: and acquiring the output voltage Ub of the brake pedal sensor.

In a specific implementation, when the brake pedal is determined to be in the free state at present, the output voltage Ub value at this time can be detected.

S405: and judging whether the driving mileage is less than or equal to 200 KM.

Since the driving range affects the free-state position of the brake pedal, in specific implementation, it can be determined whether the driving range is less than or equal to 200 KM. When the driving mileage is less than or equal to 200KM, executing S406; otherwise, S407 is executed.

S406: and judging whether the value of the output voltage Ub is in the range of Uzri.

When the output voltage Ub is in the Uzri range, S408 is performed, and conversely, S402 may be performed.

S407: and judging whether the value of the output voltage Ub is in the range of Uzll.

When the output voltage Ub is in the range Uzrl, S408 is performed, and conversely, S402 may be performed.

S408: the counter a increments by 1.

S409, whether the counter A is the threshold M of th time is judged.

In a specific implementation, the value of the output voltage Ub can be continuously detected and judged, and the detection of the value of the output voltage Ub is not stopped until the value of the counter a is the th time threshold value, as long as times that the detected value of the Ub does not meet the condition, S402 is executed, namely, the counter a clears 0 and restarts the detection of the output voltage Ub, it should be noted that, in the embodiment of the present invention, the th time threshold value M is 8.

S410: the average value of the Ub values obtained in 8 consecutive times was obtained.

In a specific implementation, when the counter a is incremented to 8, the average value of Ub values obtained by 8 detections is denoted as Uc.

S411: it is determined whether | Uc-U0 | is smaller than Δ Ua.

In this embodiment, Δ Ua is defined as the th difference threshold, and if | Uc-U0 | is < Δ Ua, S402 is executed and restarted, the th counter is cleared, and if | Uc-U0 | is ≧ Δ Ua, S412 may be executed.

S412: it is determined whether counter b is zero.

In a specific implementation, if the second counter is zero, S413 may be executed; otherwise, S414 may be performed.

S413: uc1 ═ Uc is obtained, and the counter B is incremented to 1.

That is, the average value of the output voltage Ub obtained this time is stored as Uc1, and is added to the second counter B, it should be noted that Uci represents the average value of the output voltage Ub obtained the ith time, that is, obtained when the counter B is i, as described above, when the counter B is 1, the average value of the output voltage Ub obtained correspondingly is Uc 1.

S414, determines if | Uc-UcA | is less than or equal to Δ Ub.

In this embodiment, for convenience of description, if Δ Ub indicates the second difference threshold, it may be determined whether | Uc-UcA | is less than or equal to Δ Ub when the second counter B is not 0, and S415 may be performed if | Uc-UcA | ≦ Δ Ub, and S416 may be performed otherwise. Wherein: UcA denotes the average of i Uci, i being the number stored in the counter B, i being non-zero.

Uci and CounterB are both set to zero S415.

If the condition is satisfied: | Uc-UcA | ≦ Δ Ub, and all the average values of output voltages Uc1-Uc (i) and the second counter CounterB are set to zero.

S416: CounterB + +, Uc (i +1) is calculated and stored.

In an embodiment, if | Uc-UcA | is greater than Δ Ub, the numbers i to (i +1) in the fourth counter may be updated, and the average value Uc of the output voltages Ub obtained this time may be stored as Uc (i + 1). Wherein: i +1 is the number recorded in the second counter after updating, i.e. after accumulation, i is the number recorded by the counter at S414 before S416 is not executed.

S417: it is determined whether the counter B is equal to the second decimal threshold Ndzat.

In a specific implementation, the number in calculator B is increased continuously, and when the number in calculator B is equal to Ndzat, which indicates that the condition for adjusting the current null voltage U0 is satisfied at this time, S418 may be performed, and conversely, S402 may be performed.

S418：U1＝ΣUci/Ndzat，CounterC++，CounterB＝0。

In a specific implementation, Uci can be obtained as an average value Σ Uci/Ndzat, where i is 1, 2, 3, … Kdzat in this order, that is, the Kdzat Pci is obtained as an average value, and the average value is assigned to the updated zero-position voltage U1, that is, the current U1 is updated to Σ Uci/Ndzat, and every times of updating U1, the counter C is incremented by 1, and the counter B is cleared, where the number of times of updating U1, that is, the number of times of updating the zero-position voltage, is recorded in the counter C, so as to facilitate the subsequent tracking process and better understand the working condition of the brake pedal.

S419: it is determined whether the stored U0 is the same as the stored U1.

Since the initial value of U1 is equal to the zero-position voltage U0, the updated zero-position voltage value is given to U1 only when it is confirmed that the zero-position voltage U0 is updated, it may be first judged whether the stored U0 is identical to the stored U1 when detecting the current brake pedal position, and S420 is performed when it is determined that the stored U0 is identical to the stored U1, and otherwise S421 is performed.

S420: with U0 as the reference voltage.

In a specific implementation, when it is determined that the stored U0 is the same as the stored U1, the current position of the brake pedal can be obtained by using the above formula (1) directly using U0 as a reference voltage.

S421: with U1 as the reference voltage.

In particular implementations, if it is determined that the stored U0 is not the same as the stored U1, the current position of the brake pedal can be obtained using equation (2) above.

In order to find out the failure of the brake pedal component in time, when the failure of the brake pedal sensor is detected, the specific type of the failure can be judged, and corresponding processing is executed, and specifically, referring to fig. 4b, the following details of the judgment and processing part of the failure are described:

s422: a determination is made as to whether a U0 value has been detected.

S423 may be performed when it is determined that the value of U0 is detected, and otherwise S401 is performed.

S423: the position of the brake pedal sensor is set to 100%, and the positional validity of the brake pedal sensor is set to invalid.

S424: and judging whether UGND < Ub is detected to be less than or equal to UF within the continuous time length T.

S423 may be performed when UGND < Ub ≦ UF is determined to be detected for the continuous duration T, otherwise S401 is performed.

S425: and judging whether the current Ub is detected to be larger than the UBAT in the continuous time length T or not.

S423 may be executed when it is determined that the current Ub is detected to be greater than UBAT within the continuous duration T, otherwise S401 is executed.

S426: and judging whether the current Ub is detected to be smaller than UGND in the continuous time length T.

S423 may be executed when it is determined that the current Ub is detected to be less than UGND within the continuous duration T, otherwise S401 is executed.

S427: and judging whether U0 < Ub is less than or equal to UBAT is detected in the continuous time length T.

S428 may be performed when it is determined that U0 < Ub ≦ UBAT is detected within the continuous duration T, otherwise S401 is performed.

S428: the position of the brake pedal sensor is set to 0%, and the positional validity of the brake pedal sensor is set to invalid.

p0 represents the output voltage of the initial position of the brake pedal sensor successfully detected by the electronic controller after sending a diagnostic command to the electronic controller by the diagnostic device, i.e. the ratio of the zero voltage to the input voltage corresponding thereto, P1 represents the updated zero voltage ratio, the initial value of P1 remains with P0. Pci (where i ═ 1, 2, 3, … … Kdzat) represents that, without passing through the diagnostic device, the electronic controller successfully detects that the brake pedal sensor has significantly deviated from the currently stored zero voltage ratio P0 or the updated zero voltage ratio P1 when the brake pedal is in the free state, the average of the output voltage ratios Pb at this time, written as Pci. Kdzat represents that the ratio of the output voltage of the brake pedal sensor to the input voltage has significantly deviated from the currently stored P38735 or P1 if a continuous Kdzat detects that the brake pedal sensor has been in the free state, the electronic controller needs to adjust the value P1, the counterterer represents the initial value, the counter 580, the initial value represents the second counter C, C0.

Pzri represents the ratio of the output voltage to the input voltage of the brake pedal sensor at the initial stage of its use, when it is in the free-state position. Pzll represents the ratio of the output voltage to the input voltage of the brake pedal sensor throughout its life cycle, in its free-state position, and ranges larger than pzli depending on the brake system characteristics. And the electronic controller determines Pzri and Pzrl according to the driving mileage of the whole vehicle. When the mileage of the whole vehicle is less than or equal to the preset mileage, the electronic controller considers that the brake pedal sensor is in the initial use stage, and the output voltage ratio of the initial position is within the range of Pzri.

And when the mileage of the whole vehicle is greater than the preset mileage, the electronic controller considers that the range of the output voltage ratio of the initial position of the brake pedal sensor is Pzrl. PGND represents the range of output voltage ratio Pb values corresponding to when the brake pedal sensor output is shorted to ground or open. PBAT represents the corresponding output voltage ratio Pb value range when the output of the brake pedal sensor is short-circuited to the power supply. PF represents the output voltage ratio Pb corresponding to the brake pedal sensor when the brake pedal reaches the maximum stroke. Δ Pa represents the deviation of the output voltage ratio Pb of the brake pedal sensor detected by the electronic controller from the maximum allowable range of P0 or P1 when it determines that the present brake pedal is in a free state, and when it exceeds this range, it indicates that the brake pedal free-state position has significantly deviated.

The value of Pci required to remain relatively stable when the electronic controller successfully detected series of Pci values, i.e., the deviation of any Pci values from the average of all previously obtained Pc (i-1) values cannot exceed Δ Pb. -this process is equivalent to the effect of data filtering.

The method is described in detail below with reference to fig. 3, 5a and 5b, and may include the following steps:

s501: whether a brake pedal sensor has a failure is detected.

In particular implementations, after the assembly of the relevant components of the brake pedal, the electronic controller may detect the null voltage ratio P0 of the brake pedal sensor and memorize the null voltage P0 in memory. When the whole electronic controller works, the diagnosis device needs to send a corresponding diagnosis command to the electronic controller, and when the electronic controller receives the diagnosis command, the electronic controller detects a Pb value of the brake pedal sensor, namely a ratio of output voltage and input voltage corresponding to the brake pedal in a free state position.

If the vehicle mileage is less than or equal to the preset mileage, the vehicle mileage validity is valid, and the Pb value is within the range of the voltage ratio Pzri of the th range, the current Pb value is stored and memorized as P0 to the memory, if the vehicle mileage is greater than the preset mileage, the vehicle mileage validity is valid, and the Pb value is within the range of the second voltage ratio Pzrl, the current Pb value is stored and memorized as a zero-position voltage P0 to the memory, and the value of the initialization voltage ratio parameter P1 is the acquired zero-position voltage ratio P0, and the voltage parameter P1 is the updated zero-position voltage value.

In order to timely detect the failure of the brake pedal component, in a specific implementation, whether any failure exists in the brake pedal sensor may be detected, and when no failure exists in the brake pedal sensor, S502 and S519 may be executed, or conversely, S522, S524, S525, S526 and S527 may be executed, and it should be noted that the specific execution sequence of S522, S524, S525, S526 and S527 is not limited to any particular order, and may be executed sequentially, or may be executed in parallel .

S502: initially, CounterA is 0.

And S503, judging whether the network awakening state is the network awakening source awakening network, changing the state of the driver from off to on, detecting that the whole vehicle is in a power-off state according to the state of the ignition key, and detecting that the brake lamp switch is effective and the brake lamp has no fault.

In a specific implementation, when the wakening status is that the wakening source wakens up the network, the status of the driver changes from off to on, and it is detected that the entire vehicle is in the power-off status according to the status of the ignition key, and the stop lamp switch is active and the stop lamp is not faulty, the electronic controller may determine that the current brake pedal is in the free state, and perform S504, otherwise, may continue to perform S502.

S504: and acquiring the ratio Pb of the output voltage and the input voltage of the brake pedal sensor.

In a specific implementation, when the brake pedal is determined to be in the free state at the present time, the ratio Pb of the output voltage to the input voltage at the present time may be detected.

S505: and judging whether the driving mileage is less than or equal to 200 KM.

Since the driving range affects the free-state position of the brake pedal, in specific implementation, it can be determined whether the driving range is less than or equal to 200 KM. When the driving mileage is less than or equal to 200KM, executing S506; otherwise, S507 is executed.

S506: and judging whether the output voltage ratio Pb is in the range of Pzri.

When the output voltage ratio Pb is in the range of Pzri, S508 is performed, and conversely, S502 may be performed.

S507: and judging whether the output voltage ratio Pb is in the range of Pzrl.

When the output voltage ratio Pb is in the range of pzll, S508 is performed, and conversely, S502 may be performed.

S508: the counter a increments by 1.

S509: and judging whether the counter A is the third time threshold value L or not.

In a specific implementation, the value of the output voltage ratio Pb may be continuously detected and determined, and the detection of the output voltage ratio Pb is not stopped until the value of the counter a is the third threshold value L. As long as the Pb value satisfying the condition is not detected three times in succession, S502 is executed, i.e., the counter a clears 0 and the detection of the output voltage ratio Pb is restarted.

It should be noted that, in the embodiment of the present invention, the third time threshold L is 8, in practical applications, a person skilled in the art may also set the third time threshold to other values according to practical needs, and the specific setting value of the third time threshold L does not limit the present invention in any way.

S510: the average value of the Pb values obtained in 8 consecutive cycles was obtained.

In a specific implementation, when the counter a is incremented to 8, the average value of Pb values obtained by 8 detections is recorded as Pc.

S511: judging whether Pc-P0 | is greater than or equal to Δ Pa.

In an embodiment, if | Pc-P0 | Δ Pa, then S502 is executed, and the process is restarted, and the third counter CounterA is cleared; if Pc-P0 | ≧ Δ Pa, S512 can be executed.

S512: it is determined whether counter b is zero.

In a specific implementation, if the fourth counter is zero, S513 may be executed; otherwise, S514 may be performed.

S513: pc1 is obtained as Pc, and the counter B is incremented to 1.

That is, the average value Pc of the output voltage ratio Pb obtained this time is stored as Pc1, and is added to the fourth counter, where Pci represents the average value of the output voltage ratio Pb obtained i time, that is, obtained when the counter B is i, as described above, the average value of the output voltage ratio Pb obtained when the counter B is 1 is Pc 1.

S514, determines if | Pc-PcA | is less than or equal to Δ Pb.

In a specific implementation, for convenience of description, let Δ Pb denote the fourth difference threshold. If the fourth counter B is not 0, it may be determined whether | Pc-PcA | is less than or equal to Δ Pb, and S515 may be performed if | Pc-PcA | is less than or equal to Δ Pb, otherwise, S516 may be performed. Wherein: PcA denotes the average of i Pci, i being the number stored in the counter B, i being non-zero.

And S515, setting Pci and CounterB to zero.

If Pc-PcA ≦ Δ Pb, all the average values of the output voltages Pc1-Pc (i) and the fourth counter CounterB are set to zero.

S516: CounterB + +, Pc (i +1) is calculated and stored.

In an embodiment, if | Pc-PcA | is greater than Δ Pb, the numbers i to (i +1) in the fourth counter b may be updated, and the average value Pc of the output voltage ratio Pb obtained this time may be stored as Pc (i + 1). Wherein: i +1 is the number recorded in the fourth counter countb after updating, i.e., after accumulation, and i is the number recorded in the fourth counter countb at the time of S514 before S516 is not performed.

S517: it is determined whether the counter B is equal to the fourth time threshold Kdzat.

In a specific implementation, if the counter B is equal to the fourth time threshold value Kdzat, that is, the number in the calculator B is continuously incremented, when the number in the calculator B is equal to Kdzat, indicating that the condition for adjusting the current zero-bit voltage ratio P0 is satisfied at this time, S518 may be executed, and conversely, S502 may be executed.

S518：P1＝ΣPci/Kdzat，CounterC++，CounterB＝0。

In a specific implementation, the average value Σ Pci/Kdzat of Pci may be obtained, where i is sequentially 1, 2, 3, … … Kdzat, that is, the average value of Kdzat Pci is obtained, and this average value is assigned to the updated zero-position voltage ratio P1, that is, the current P1 is updated to Σ Pci/Kdzat, and every updates P1 times, the counter C increments by 1, and the counter B is cleared, where the number of updates of P1, that is, the number of updates of the zero-position voltage, is recorded in the counter C, so as to facilitate the subsequent tracking process and better understand the working condition of the brake pedal.

S519: it is determined whether the stored P0 is the same as the stored P1.

Since the initial value of P1 is equal to the zero-position voltage ratio P0, the updated zero-position voltage ratio is given to P1 only when it is confirmed that the zero-position voltage ratio P0 is updated, it may be first determined whether the stored P0 is identical to the stored P1 when detecting the current brake pedal position, and S520 is performed when it is determined that the stored P0 is identical to the stored P1, and S521 is performed otherwise.

S520: p0 is taken as the reference voltage ratio.

In a specific implementation, when it is determined that the stored P0 is the same as the stored P1, the current position of the brake pedal can be obtained by using the above equation (3) directly using P0 as the reference voltage ratio:

S＝100×(P0-P)/(P0-PF)％-offsetS (3)

wherein: s is a current position of the brake pedal, offsetS is a drift position amount that is allowed to actually occur to the brake pedal during the period of judging whether the zero voltage is updated, a specific value thereof may be obtained through engineering verification and bench test, and PF is a ratio of an output voltage of the corresponding brake pedal sensor to an input voltage corresponding thereto when the brake pedal reaches the maximum stroke.

S521: p1 is taken as the reference voltage ratio.

In a specific implementation, if it is determined that the stored P0 is not the same as the stored P1, the current position of the brake pedal can be obtained using the above equation (4):

S＝100×(P1-P)/(P1-PF)％-offsetS (4)

in order to find out the failure of the brake pedal component in time, when the failure of the brake pedal sensor is detected, the specific type of the failure can be judged, and corresponding processing is executed, and specifically, referring to fig. 3 and fig. 5b, the following details of the judgment and processing of the failure are described:

s522: a determination is made as to whether a P0 value was detected.

When it is determined that the P0 value is detected, S523 may be performed, whereas S501 is performed.

S523: the position of the brake pedal sensor is set to 100%, and the positional validity of the brake pedal sensor is set to invalid.

S524: and judging whether PGND < Pb < PF is detected within the continuous time T.

S523 may be performed when it is determined that PGND < Pb ≦ PF is detected within the continuous time period T, whereas S501 may be performed otherwise.

S525: and judging whether the current Pb is larger than the PBAT or not within the continuous time length T.

When it is determined that Pb is greater than PBAT currently detected within the continuous duration T, S523 may be performed, otherwise S501 is performed.

S526: and judging whether the current Pb is smaller than PGND within the continuous time length T.

S523 may be performed when it is determined that the current Pb is less than PGND detected within the continuous time period T, and otherwise, S501 may be performed.

S527: and judging whether P0 < Pb < PBAT is detected in the continuous time length T or not.

S528 may be performed when it is determined that P0 < Pb ≦ PBAT is detected within the continuous duration T, otherwise S501 is performed.

S528: the position of the brake pedal sensor is set to 0%, and the positional validity of the brake pedal sensor is set to invalid.

In order to make those skilled in the art better understand and implement the present invention, the following also provides an apparatus which can implement the position detection method of the brake pedal described above, and referring to fig. 6, the apparatus may include an th acquisition unit 601, a detection unit 602, a th judgment unit 603, and a th position detection unit 604, wherein:

an obtaining unit 601, adapted to obtain a zero voltage U0 of the brake pedal, wherein the zero voltage U0 is a reference voltage for calculating the position of the brake pedal;

a detection unit 602 adapted to detect an output voltage Ub of a brake pedal sensor corresponding to a zero braking force applied to the brake pedal;

an th judging unit 603 adapted to judge whether to update the zero voltage U0 according to a relationship between the output voltage Ub of the brake pedal sensor corresponding to a zero braking force applied to the brake pedal and the zero voltage U0;

an position detecting unit 604, adapted to detect the position of the brake pedal according to the relationship among the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF when the determining unit 603 determines to update the zero-position voltage U0, wherein the maximum output voltage UF is the output voltage of the brake pedal sensor corresponding to the maximum stroke of the brake pedal.

In a specific implementation, the th obtaining unit 601 may include:

, a detecting subunit 6011 adapted to detect an output voltage of a brake pedal sensor corresponding to a zero braking force applied to the brake pedal when the brake pedal assembly is assembled;

an th voltage selecting subunit 6013 adapted to use the output voltage detected by the th detecting subunit 6011 as the zero voltage U0.

In a specific implementation, the brake pedal assembly includes any of off-line testing of a vehicle on which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the device for brake pedal position detection.

In a specific implementation, the th obtaining unit 601 may further include:

an th judging subunit 6012 adapted to, after the th detecting subunit 6011 detects the output voltage, judge whether at least conditions that the driving mileage of the vehicle is a valid number, is less than or equal to a preset mileage, and the output voltage belongs to a preset th voltage range, the driving mileage of the vehicle is a valid number, is greater than the preset mileage, and the output voltage belongs to a preset second voltage range are satisfied;

the th voltage selecting subunit 6013 is further adapted to use the output voltage detected by the th detecting subunit 6011 as the zero voltage U0 when the th judging subunit 6012 determines that the output voltage satisfies the at least conditions.

The following provides a schematic structural diagram of the -type judging unit 603 in the embodiment of the present invention, and as described in detail below with reference to fig. 7, the -type judging unit 603 may include:

a second detection subunit 71, adapted to detect an output voltage Ub of the brake pedal sensor corresponding to a zero braking force applied to the brake pedal;

an th calculation subunit 72 adapted to find an average value Uc of the output voltage Ub meeting the th storage condition when the output voltage Ub meets the th storage condition for a preset th threshold;

, an updating subunit 73, adapted to determine to update the zero voltage U0 when the Uc satisfies a preset second storage condition continuously reaching a preset second time threshold, and to find an average value of the Uc satisfying the second storage condition as an updated zero voltage U0.

In a specific implementation, the th calculation subunit 72 may include:

an storage module 721 adapted to store the output voltage Ub when it meets the storage condition;

an th counter 722 adapted to count the number of the output voltages Ub stored in the th storage module 721;

an calculating module 723, adapted to find the average value Uc of the stored th threshold number of the output voltages Ub when the th counter 722 is continuously incremented and equals to a preset th threshold number;

an th judging module 724 adapted to judge whether an absolute value of a difference between the average value Uc and the zero voltage U0 is less than a preset th difference threshold;

an th control module 725 adapted to, when it is determined that the absolute value of the difference between the average value Uc and the zero-position voltage U0 is less than the th difference threshold, clear the th counter 722 and control the second detecting unit 602 to re-execute the step of detecting the output voltage Ub of the brake pedal sensor corresponding to a zero braking force applied to the brake pedal.

In specific implementation, the storage condition is any conditions, wherein the driving distance of the vehicle is valid data and is less than or equal to a preset distance, and the output voltage belongs to a preset voltage ratio range, and the driving distance of the vehicle is valid data and is greater than the preset distance, and the voltage belongs to a preset second voltage ratio range.

In a specific implementation, the th updating subunit 73 includes:

a second determining module 731, adapted to determine whether the second counter 733 is zero when it is determined that the absolute value of the difference between the average value Uc of the output voltage and the zero voltage U0 is greater than or equal to the th difference threshold;

an recording module 732 adapted to record an average value Uc of the output voltage when the second counter 733 is zero, as a average value Uc 1;

a second counter 733 adapted to record the number of average values Uc of said output voltages;

a third determining module 734, adapted to determine whether an absolute value of a difference between the average value Uc of the current output voltage and the reference output voltage average value UcA is less than or equal to a preset second difference threshold when it is determined that the second counter 733 is i and i is not zero; wherein: the reference output voltage average value UcA is the average value of the previous i output voltage average values Uc;

a second control module 735 adapted to zero all of said average values of output voltages Uc-Uc (i) and said second counter 733, when it is determined that the absolute value of the difference between said average value of output voltages Uc and said average value of reference output voltages UcA is greater than said second difference threshold;

a third control module 736 adapted to add to the second counter 733 upon determining that the absolute value of the difference between the average value Uc of the output voltage of the current time and the reference output voltage average value UcA is less than the second difference threshold, control recording the average value Uc of the output voltage of the current time as the (i +1) th output voltage average value Uc (i + 1);

a fourth judging module 737 adapted to judge whether the value i in the second counter 733 is equal to a preset second-time threshold Ndzat; when it is determined that the value i in the second counter 733 is equal to a preset second-count threshold value Ndzat, it is determined that the Uc satisfies the second storage condition continuously up to the second-count threshold value.

In a specific implementation, the second storage condition is: the absolute value of the difference between the average value Uc of the output voltage at the current time and the reference output voltage average value UcA is less than or equal to the second difference threshold.

In order to timely identify a fault condition, as shown in fig. 8, the apparatus may further include an th fault handling unit 801 adapted to set the position signal of the brake pedal sensor to 100% and to set the position validity of the brake pedal sensor to invalid when the current output voltage U is detected to be less than a preset th voltage threshold UGND for a continuous preset time period T.

In a specific implementation, the apparatus may further include: a second fault handling unit 802 adapted to set the position signal of the brake pedal sensor to 100% and to set the validity of the position of the brake pedal sensor to invalid when it is detected that the current output voltage U is greater than a preset second voltage threshold UBAT for a continuous preset time period T.

In a specific implementation, the apparatus may further include: a third fault handling unit 803, adapted to detect that the current output voltage U is less than or equal to a preset second voltage threshold U within a continuous preset time period T_BATAnd is greater than the zero voltage U before updating₀The position signal of the brake pedal sensor is set to 0%, and the validity of the position of the brake pedal sensor is set to invalid.

In a specific implementation, the apparatus may further include a fourth fault handling unit 804, adapted to detect that the current output voltage U is greater than the th voltage threshold value U within a preset time period T_GNDAnd is less than the maximum output voltage U_FThe position signal of the brake pedal sensor is set to 100%, and the validity of the position of the brake pedal sensor is set to invalid.

In a specific implementation, the apparatus may further include: a fifth fault handling unit 805 adapted to handle a zero voltage U when the zero voltage U is not obtained₀The position signal of the brake pedal sensor is set to 100%, and the validity of the position of the brake pedal sensor is set to invalid.

In order to avoid the influence of the input voltage on the detection result of the brake pedal position, another device for detecting the brake pedal position in the embodiment of the present invention is shown below, and is described below with reference to fig. 9, wherein the device may further include a second acquiring unit 901, a th calculating unit 902, a second calculating unit 903 and a second position detecting unit 907, wherein:

a second obtaining unit 901 adapted to obtain an input voltage corresponding to a zero voltage U0 of the brake pedal;

an calculation unit 902 adapted to calculate a ratio of the null voltage U0 and the input voltage as a null voltage ratio P0, the null voltage ratio P0 being a reference voltage ratio for calculating a brake pedal position;

a second calculating unit 903 adapted to calculate a ratio of the current output voltage U to an input voltage corresponding thereto as a current output voltage ratio P;

a second position detecting unit 907 adapted to detect the position of the brake pedal according to the relationship among the current output voltage P, the zero voltage ratio P0 and the maximum output voltage ratio PF, wherein: the maximum output voltage ratio PF is the ratio of the maximum output voltage UF to its corresponding input voltage.

In a specific implementation, the apparatus may further include:

a third calculating unit 905 adapted to calculate a ratio Pb of the output voltage Ub to an input voltage corresponding to the output voltage Ub;

the second judging unit 906 is adapted to judge whether to update the zero voltage ratio P0 according to a relation between the ratio Pb of the input voltage and the zero voltage ratio P0;

the second position detecting unit 907 is further adapted to detect the position of the brake pedal according to a relationship among the current output voltage P of the brake pedal sensor, the updated zero-position voltage ratio P0, and the maximum output voltage ratio PF when the second determining unit 906 determines to update the zero-position voltage ratio P0.

In a specific implementation, the th calculating unit 902 is adapted to detect the output voltage and the input voltage of the brake pedal sensor corresponding to the brake pedal receiving zero braking force after the brake pedal assembly is assembled, and use the ratio of the output voltage and the input voltage as the zero-position voltage ratio P0.

In a specific implementation, the pedal assembly is assembled by any of offline testing of a vehicle on which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the device for detecting the position of the brake pedal.

In a specific implementation, the device further includes a third determining unit 908, adapted to determine that a ratio of the output voltage to the input voltage satisfies at least conditions that a driving range of the vehicle is an effective number and less than or equal to a preset range, the ratio of the output voltage to the input voltage belongs to a preset voltage ratio range, the driving range of the vehicle is an effective number and more than or equal to a preset range, and the ratio of the output voltage to the input voltage belongs to a preset second voltage ratio range, before detecting an output voltage and an input voltage of a brake pedal sensor corresponding to a brake pedal subjected to zero braking force after the brake pedal assembly is assembled, and before the ratio of the output voltage to the input voltage is taken as a zero voltage ratio P0.

The following shows a structure diagram of types of second determining unit 906 in the embodiment of the present invention, as shown in fig. 10, in a specific implementation, the second determining unit 906 includes:

a third detection subunit 101, adapted to detect a ratio Pb of an output voltage to an input voltage of a brake pedal sensor corresponding to a zero braking force applied to the brake pedal;

the second calculating subunit 102 is adapted to, when the ratio Pb meets a preset third storage condition and continues to reach a preset third time threshold, obtain an average value Pc of the voltage ratio Pb meeting the third storage condition;

the second updating subunit 103 is adapted to determine to update the null voltage ratio P0 when the Pc meets a preset fourth storage condition for a preset fourth time threshold, and find an average value of the Pc meeting the fourth storage condition as an updated null voltage ratio P0.

In a specific implementation, the second calculating subunit 102 includes:

the second detection module 1026 is adapted to detect a ratio Pb of an output voltage and an input voltage of the brake pedal sensor corresponding to a brake force applied to the brake pedal being zero;

a second storage module 1021, adapted to store the ratio Pb of the voltages when the ratio Pb of the voltages satisfies the third storage condition;

a third counter 1022, adapted to record the number of ratio values Pb in the second storage module 1021;

a second calculating module 1023, adapted to obtain an average value Pc of the stored ratio Pb of the voltages of the preset third-time threshold value until the third counter 1022 continuously increases and is equal to the preset third-time threshold value;

a fifth determining module 1024, configured to determine whether an absolute value of a difference between the average value Pc and the zero voltage ratio P0 is smaller than a preset third difference threshold;

and the fourth control module 1025 is adapted to clear the third counter 1022 when the absolute value of the difference between the average value Pc and the zero-position voltage ratio P0 is smaller than the third difference threshold, and to re-execute the step of detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the brake pedal receiving zero braking force.

In a specific implementation, the third storage condition is any of the following conditions that the driving distance of the vehicle is valid data, is less than or equal to a preset distance and the voltage ratio belongs to a preset voltage ratio range, and the driving distance of the vehicle is valid data, is greater than the preset distance and the voltage ratio belongs to a preset second voltage ratio range.

In a specific implementation, the second updating subunit 103 includes:

a sixth determining module 1031, adapted to determine whether the fourth counter 1033 is zero when the absolute value of the difference between the average value Pc of the voltage ratios and the zero-position voltage ratio P0 is greater than or equal to the third difference threshold;

a second recording module 1032 adapted to record the average value Pc of the voltage ratio as the -th output voltage ratio average value Pc1 when the fourth counter 1033 is zero;

a fourth counter 1033 adapted to count the number of said average values Pc1 in said second recording module 1032;

a seventh determining module 1034, configured to determine whether an absolute value of a difference between the current voltage ratio average Pc and the reference voltage ratio average PcA is less than or equal to a preset fourth difference threshold when the fourth counter 1033 is i and i is not zero; wherein: the reference voltage ratio average PcA is the average of the previous i voltage ratio averages;

a fifth control module 1035 adapted to zero all of the voltage ratio averages Pc1-Pc (i) and the fourth counter 1033 when the absolute value of the difference between the voltage ratio average Pc and the reference voltage ratio average PcA is greater than the fourth difference threshold;

a sixth control module 1036 adapted to add to said fourth counter 1033 when the absolute value of the difference between said average value Pc of the current voltage ratio and said average value PcA of the reference voltage ratio is less than said fourth difference threshold, and record said average value Pc of the current voltage ratio as the average value Pc (i +1) of the (i +1) th voltage ratio;

an eighth determining module 1037, adapted to determine whether the value i in the fourth counter 1033 is equal to a preset fourth time threshold Kdzat; when the value i in the fourth counter 1033 is equal to a preset fourth time threshold value Kdzat, it is determined that the Pc satisfies the fourth storage condition for the fourth time threshold value.

In a specific implementation, the fourth storage condition is: the absolute value of the difference between the average value Pc of the voltage ratio of the current time and the average value PcA of the reference voltage ratio is less than or equal to the fourth difference threshold.

In order to timely identify a fault, another brake pedal position detection apparatus according to an embodiment of the present invention is provided, and as shown in fig. 11, the apparatus may further include a seventh fault processing unit 1102 adapted to set the position signal of the brake pedal sensor to 100% and set the position validity of the brake pedal sensor to invalid when detecting that the voltage ratio P is greater than a second preset voltage ratio threshold PBAT within a continuous preset time period T.

In a specific implementation, the apparatus may further include: the eighth fault processing unit 1103 is adapted to, when it is detected within the continuous preset time period T that the voltage ratio P is less than or equal to a preset second voltage ratio threshold PBAT and greater than the zero voltage ratio P0 before updating, set the position signal of the brake pedal sensor to 0%, and set the validity of the position of the brake pedal sensor to invalid.

In a specific implementation, the apparatus may further include a ninth fault handling unit 1104, adapted to set the position signal of the brake pedal sensor to 100% and set the position validity of the brake pedal sensor to invalid when it is detected that the voltage ratio P is greater than the -th voltage ratio threshold PGND and less than the maximum output voltage ratio PF within a continuous preset time period T.

In a specific implementation, the apparatus may further include: a tenth fault handling unit 1105 adapted to set the position signal of the brake pedal sensor to 100% and to set the position validity of the brake pedal sensor to invalid when the zero-position voltage ratio P0 is not obtained.

Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer-readable storage medium, and the storage medium may include: ROM, RAM, magnetic or optical disks, and the like.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

A method of brake pedal position detection, , comprising:

acquiring a zero voltage U0 of the brake pedal, wherein the zero voltage U0 is a reference voltage for calculating the position of the brake pedal;

detecting the output voltage Ub of a brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero;

judging whether to update the zero voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to the brake pedal when the braking force applied to the brake pedal is zero and the zero voltage U0;

when the zero-position voltage U0 is determined to be updated, detecting the position of the brake pedal according to the relation among the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF, wherein: the maximum output voltage UF is the output voltage of the corresponding brake pedal sensor when the brake pedal reaches the maximum stroke;

the judging whether to update the zero voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to the brake pedal when the braking force applied to the brake pedal is zero and the zero voltage U0 includes:

when the output voltage Ub meets a preset storage condition and continuously reaches a preset time threshold, obtaining an average value Uc of the output voltage Ub meeting a storage condition, determining to update the zero-position voltage U0 when the average value Uc meets a preset second storage condition and continuously reaches a preset second time threshold, and obtaining an average value 539 of the average value Uc meeting the second storage condition as an updated zero-position voltage U2;

determining whether the Uc satisfies a predetermined second storage condition for a predetermined second threshold value, including determining whether a second counter is zero when an absolute value of a difference between an average Uc of the output voltage Ub and the zero-bit voltage U0 is greater than or equal to a th difference threshold value, recording the average Uc of the output voltage as a th output voltage average Uc1 and adding to the second counter when the second counter is zero, determining whether an absolute value of a difference between the average Uc of the output voltage and a reference output voltage average UcA is less than or equal to a predetermined second difference threshold value when the second counter is i and i is not zero, wherein the reference output voltage average UcA is an average of previous i output voltage averages UcA, setting all of the average Uc of the output voltage 2-Uc) and the average of the reference output voltage UcA as the second difference threshold value, when the absolute value of the difference between the average Uc of the output voltage and the reference output voltage average of the reference voltage average UcA is greater than the second difference threshold value, determining whether the average Uc 2-Uc and the absolute value of the second counter are equal to the second threshold value of the second counter when the absolute value of the average Uc + 4934, the average Uc is less than the second threshold value, and the second threshold value of the second counter is equal to the predetermined second threshold value, and the second threshold value, determining whether the average value of the average Uc + Ndi + 7 is equal to the second threshold value, and the second threshold value, wherein the second counter is equal to the second threshold value, and the second threshold value of the second counter, and the second counter is equal to the second threshold value of the second;

the storage condition is any of the following conditions that the driving distance of the vehicle is valid data, the driving distance is less than or equal to a preset distance and the output voltage belongs to a preset voltage range, and the driving distance of the vehicle is valid data, the driving distance is greater than the preset distance and the output voltage belongs to a preset second voltage range.
2. The method for detecting the position of the brake pedal as claimed in claim 1, wherein the obtaining of the zero voltage U0 of the brake pedal comprises:

and when the brake pedal assembly is assembled, detecting the output voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero, wherein the output voltage is used as the zero voltage U0.
3. The method of brake pedal position sensing according to claim 2, wherein the brake pedal assembly is assembled including any of offline testing of a vehicle in which the brake pedal is installed, replacement of the brake pedal sensor, and replacement of the device for brake pedal position sensing.
4. The method for detecting the position of the brake pedal according to claim 3, wherein after detecting the output voltage of the brake pedal sensor corresponding to zero braking force applied to the brake pedal after the assembly of the brake pedal assembly, and before using the detected output voltage as the zero voltage U0, the method further comprises:

determining that the output voltage satisfies at least of the following conditions:

the driving mileage of the vehicle is an effective number, is less than or equal to a preset mileage and the output voltage belongs to a preset th voltage range;

the driving mileage of the vehicle is a valid number, is greater than the preset mileage, and the output voltage belongs to a preset second voltage range.
5. The method of brake pedal position sensing according to claim 1, wherein said averaging Uc of the output voltage Ub satisfying the th storage condition when the output voltage Ub satisfies the preset th storage condition for a preset th threshold number of consecutive times comprises:

storing the output voltage Ub and adding to a counter when the output voltage Ub satisfies the th storage condition;

until the th counter is continuously increased and is equal to a preset th time threshold value, calculating an average value Uc of the output voltage Ub of the th time threshold value;

and when the absolute value of the difference value between the average value Uc of the output voltage Ub and the zero-position voltage U0 is smaller than a preset difference value threshold, clearing the counter, and executing the step of detecting the output voltage Ub of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero again.
A method of brake pedal position detection, comprising:

acquiring an input voltage corresponding to a zero voltage U0 of a brake pedal;

calculating the ratio of the zero voltage U0 to the input voltage as a zero voltage ratio P0, wherein the zero voltage ratio P0 is a reference voltage ratio for calculating the position of the brake pedal;

calculating the ratio Pb of the output voltage Ub to the input voltage corresponding to the output voltage Ub;

judging whether to update the zero voltage ratio P0 according to the relation between the ratio Pb of the input voltage and the zero voltage ratio P0;

when the zero-position voltage ratio P0 is determined to be updated, detecting the position of the brake pedal according to the relation among the current output voltage ratio P of the brake pedal sensor, the updated zero-position voltage ratio P0 and the maximum output voltage ratio PF; wherein: the maximum output voltage ratio PF is the ratio of the maximum output voltage UF and the corresponding input voltage;

the judging whether to update the zero voltage ratio P0 according to the relation between the ratio Pb of the input voltage and the zero voltage ratio P0 includes: detecting the ratio Pb of the output voltage and the input voltage of a brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero; when the ratio Pb meets a preset third storage condition and continuously reaches a preset third time threshold value, calculating an average value Pc of the voltage ratio Pb meeting the third storage condition; when the Pc meets a preset fourth storage condition and continuously reaches a preset fourth number threshold, determining to update the zero voltage ratio P0, and solving an average value of the Pc meeting the fourth storage condition as an updated zero voltage ratio P0;

judging whether the Pc meets a preset fourth storage condition, including judging whether a fourth counter is zero when the absolute value of the difference between the average value of the voltage ratios Pc and the zero-position voltage ratio P0 is greater than or equal to a third difference threshold, recording the average value of the voltage ratios Pc as the th output voltage ratio average value Pc1 and adding to the fourth counter when the fourth counter is zero, judging whether the absolute value of the difference between the average value of the voltage ratios Pc and the reference voltage ratio average value PcA is less than or equal to a preset fourth difference threshold when the fourth counter is i and i is not zero, wherein the reference voltage ratio average value PcA is the average value of the previous i voltage ratio averages, setting all the voltage ratio average values 1-Pc (i) and the fourth counter to zero when the absolute value of the difference between the average value of the voltage ratios Pc and the reference voltage ratio average value PcA is greater than the fourth difference threshold, determining whether the absolute value of the difference value of the Pc and the reference voltage ratio average value PcA is equal to the preset fourth difference threshold + t when the absolute value of the Pc and the Pc is greater than the preset fourth difference threshold, determining whether the absolute value of the difference value of the Pc + t is equal to the fourth counter, and the fourth counter is equal to the fourth difference threshold, wherein the fourth counter 361;

the third storage condition is any of the following conditions that the driving mileage of the vehicle is effective data, is less than or equal to a preset mileage and belongs to a preset voltage ratio range, and the driving mileage of the vehicle is effective data, is greater than the preset mileage and belongs to a preset second voltage ratio range.
7. The method of brake pedal position sensing according to claim 6, said calculating a ratio of said null voltage U0 and said input voltage as a null voltage ratio P0, comprising:

after the brake pedal assembly is assembled, detecting the output voltage and the input voltage of a corresponding brake pedal sensor when the braking force applied to the brake pedal is zero, and taking the ratio of the output voltage and the input voltage as a zero-position voltage ratio P0.
8. The method of brake pedal position sensing of claim 7 wherein said brake pedal assembly is assembled including any of offline testing of a vehicle to which said brake pedal is installed, replacement of said brake pedal sensor, and replacement of said brake pedal position sensing device.
9. The method for detecting the position of the brake pedal according to claim 7, wherein the step of determining the ratio of the output voltage to the input voltage of the brake pedal sensor after detecting that the braking force applied to the brake pedal is zero after the assembly of the brake pedal assembly is performed as the zero-position voltage ratio P0 further comprises:

determining that the ratio of the output voltage to the input voltage satisfies at least of the following conditions:

the driving mileage of the vehicle is an effective number, is less than or equal to a preset mileage and the ratio of the output voltage to the input voltage belongs to a preset -th voltage ratio range;

the driving mileage of the vehicle is a valid number, the driving mileage is larger than the preset mileage, and the ratio of the output voltage to the input voltage belongs to a preset second voltage ratio range.
10. The method of brake pedal position detection according to claim 6, wherein said averaging Pc of the voltage ratios Pb that satisfy a third storage condition when the ratios Pb satisfy the third storage condition continuously for a third threshold value includes:

detecting the ratio Pb of the output voltage and the input voltage of a brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero;

when the ratio Pb of the voltages satisfies the third storage condition, storing the ratio Pb of the voltages and adding a third counter;

until the third counter continuously increases and is equal to a preset third time threshold, calculating an average value Pc of the stored ratio Pb of the preset third time threshold to the voltage;

and when the absolute value of the difference value between the average value Pc and the zero voltage ratio P0 is smaller than a preset third difference threshold value, resetting the third counter, and executing the step of detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero again.
11, A brake pedal position sensing apparatus, comprising:

an acquisition unit, which is suitable for acquiring a zero voltage U0 of the brake pedal, wherein the zero voltage U0 is a reference voltage for calculating the position of the brake pedal;

the detection unit is suitable for detecting the output voltage Ub of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero;

an th judging unit, adapted to judge whether to update the zero voltage U0 according to the relation between the output voltage Ub of the brake pedal sensor corresponding to the zero position voltage U0 when the braking force applied to the brake pedal is zero;

an position detecting unit, adapted to detect the position of the brake pedal according to the relationship among the current output voltage U of the brake pedal sensor, the updated zero-position voltage U0 and the maximum output voltage UF when the determining unit determines to update the zero-position voltage U0, wherein the maximum output voltage UF is the output voltage of the brake pedal sensor corresponding to the maximum stroke of the brake pedal;

the judgment unit comprises a second detection subunit, a calculation subunit, a updating subunit and a second judgment subunit, wherein the second detection subunit is suitable for detecting the output voltage Ub of the brake pedal sensor corresponding to zero braking force applied to the brake pedal, the calculation subunit is suitable for obtaining the average value Uc of the output voltage Ub meeting the storage condition when the output voltage Ub meets the preset storage condition and continuously reaches the preset threshold for times, and the updating subunit is suitable for determining and updating the zero voltage U0 and obtaining the average value of the Uc meeting the second storage condition as the updated zero voltage U0 when the Uc meets the preset second storage condition and continuously reaches the preset second threshold for times;

the updating subunit comprises a second judging module, a recording module, a third judging module, a second control module, a third judging module, a fourth control module, a fourth judging module and a third judging module, wherein the second judging module is suitable for judging whether the absolute value of the difference value between the average value Uc of the output voltage and the reference voltage average value UcA is larger than or equal to a preset second difference threshold value when the absolute value of the difference value between the average value Uc of the output voltage and the zero-position voltage U0 is larger than or equal to a difference threshold value, whether the second counter is zero, the recording module is suitable for recording the average value Uc of the output voltage when the second counter is zero, and using the recorded average value Uc of the output voltage as the output voltage average value Uc1, the second counter is suitable for recording the number of the average value Uc of the average value of the output voltage, the third judging module is suitable for storing the absolute value of the average value Uc + Ndi of the output voltage as the second counter when the absolute value of the second counter is larger than or smaller than the preset second threshold value, and when the absolute value of the second counter is smaller than or equal to the second counter, and the absolute value of the second counter is smaller than or equal to the preset second threshold value, and when the absolute value of the second counter is equal to the absolute value of the second counter, and when the absolute value of the second counter is determined by the second counter, the second counter is equal to control module, the absolute value of the average value of the absolute value of the second counter is equal to control module UcA, and the absolute value of the;

the storage conditions are any conditions that the driving distance of the vehicle is valid data, the driving distance is less than or equal to a preset distance and the output voltage belongs to a preset voltage ratio range, and the driving distance of the vehicle is valid data, the driving distance is greater than the preset distance and the output voltage belongs to a preset second voltage ratio range.
12. The brake pedal position detecting apparatus according to claim 11, wherein the th acquisition unit includes:

, a detection subunit, adapted to detect the output voltage of the corresponding brake pedal sensor when the brake pedal assembly is assembled and the brake force applied to the brake pedal is zero;

an th voltage selection subunit adapted to select the output voltage detected by the th detection subunit as the zero voltage U₀。
13. The brake pedal position sensing apparatus of claim 12, wherein the brake pedal assembly is assembled to include any of offline testing of a vehicle to which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the brake pedal position sensing apparatus.
14. The brake pedal position detecting apparatus according to claim 12, wherein the th acquisition unit further includes:

an th judgment subunit, adapted to judge whether at least conditions that the vehicle has a mileage as a valid number, is less than or equal to a preset mileage, and the output voltage belongs to a preset th voltage range, that the vehicle has a mileage as a valid number, is greater than the preset mileage, and the output voltage belongs to a preset second voltage range, are met after the th detection subunit detects the output voltage;

the th voltage selecting subunit is further adapted to use the output voltage detected by the th detecting subunit as the zero voltage U0 when the th judging subunit determines that the output voltage satisfies the at least conditions.
15. The brake pedal position sensing apparatus of claim 11, wherein the th calculation subunit includes:

an storage module adapted to store the output voltage Ub when the output voltage Ub satisfies the storage condition;

an th counter adapted to count the number of the output voltages Ub stored in the th storage module;

an calculation module, adapted to find the average value Uc of the stored th threshold number of the output voltage Ub when the th counter is continuously incremented and equal to a preset th threshold number;

an th judgment module, adapted to judge whether the absolute value of the difference between the average value Uc and the zero voltage U0 is less than a preset th difference threshold;

and the control module is suitable for clearing the counter when the absolute value of the difference value between the average value Uc and the zero-position voltage U0 is determined to be smaller than the difference value threshold, and controlling the second detection unit to execute the step of detecting the output voltage Ub of the brake pedal sensor corresponding to the brake pedal with zero braking force again.
16, A brake pedal position sensing apparatus, comprising:

a second obtaining unit adapted to obtain an input voltage corresponding to a zero voltage U0 of the brake pedal;

an calculation unit adapted to calculate a ratio of the zero voltage U0 and the input voltage as a zero voltage ratio P0, the zero voltage ratio P0 being a reference voltage ratio for calculating a brake pedal position;

the second calculating unit is suitable for calculating the ratio of the current output voltage U to the input voltage corresponding to the current output voltage U as the current output voltage ratio P;

a second position detection unit, adapted to detect the position of the brake pedal according to the relationship among the current output voltage ratio P, the zero voltage ratio P0 and the maximum output voltage ratio PF, wherein: the maximum output voltage ratio PF is the ratio of the maximum output voltage UF to the corresponding input voltage;

the third calculating unit is suitable for calculating the ratio Pb of the output voltage Ub to the input voltage corresponding to the output voltage Ub;

the second judging unit is suitable for judging whether to update the zero voltage ratio P0 according to the relation between the ratio Pb of the input voltage and the zero voltage ratio P0;

the second position detection unit is further adapted to detect the position of the brake pedal according to the relationship among the current output voltage ratio P of the brake pedal sensor, the updated zero-position voltage ratio P0 and the maximum output voltage ratio PF when the second judgment unit determines to update the zero-position voltage ratio P0;

the second determination unit includes: the third detection subunit is suitable for detecting the ratio Pb of the output voltage and the input voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero;

the second calculating subunit is suitable for calculating an average value Pc of the voltage ratio Pb meeting the third storage condition when the ratio Pb meets the preset third storage condition and continuously reaches a preset third time threshold; a second updating subunit, adapted to determine to update the null voltage ratio P0 when the Pc meets a preset fourth storage condition for a preset fourth number threshold, and find an average value of the Pc meeting the fourth storage condition as an updated null voltage ratio P0;

the second updating subunit comprises a sixth judging module, a second recording module, a seventh judging module, a fifth control module and a fourth comparing module, wherein the sixth judging module is suitable for judging whether a fourth counter is zero or not when the absolute value of the difference between the average value Pc of the voltage ratios and the zero-position voltage ratio P0 is greater than or equal to a third difference threshold value, the second recording module is suitable for recording the average value Pc of the voltage ratios as a th output voltage ratio average value Pc1 when the fourth counter is zero, the fourth counter is suitable for calculating the number of the average values Pc1 in the second recording module, the seventh judging module is suitable for judging whether the absolute value of the difference between the average value Pc of the next voltage ratios and a reference voltage ratio average value PcA is less than or equal to a preset fourth difference threshold value when the fourth counter is i and i is not zero, wherein the reference voltage ratio average value PcA is the average value of the previous i voltage ratio averages, the fifth control module is suitable for judging whether the absolute value Pc of the fourth counter is equal to the fourth counter when the absolute value of the difference between the average value Pc PcA and the fourth voltage ratio Pc + t is greater than the preset fourth difference value, the fourth threshold value of the fourth counter is suitable for judging whether the fourth counter when the absolute value Pc + t of the absolute value of the fourth counter is equal to be equal to the absolute value of the fourth difference value of the fourth threshold value of the fourth counter 351, and the absolute value of the fourth counter is equal to the absolute value of the fourth threshold value of the fifth judging module, and the absolute value of the fifth judging module is equal to be equal to the absolute value of the fourth threshold;

the third storage condition is any of the following conditions that the driving mileage of the vehicle is effective data, is less than or equal to a preset mileage and belongs to a preset voltage ratio range, and the driving mileage of the vehicle is effective data, is greater than the preset mileage and belongs to a preset second voltage ratio range.
17. The brake pedal position detecting apparatus according to claim 16, wherein the -th calculating unit is adapted to detect the output voltage and the input voltage of the brake pedal sensor corresponding to a zero braking force applied to the brake pedal when the brake pedal assembly is assembled, and to use the ratio of the output voltage and the input voltage as a zero voltage ratio P0.
18. The brake pedal position sensing apparatus of claim 17, wherein the pedal assembly includes any of offline testing of a vehicle to which the brake pedal is mounted, replacement of the brake pedal sensor, and replacement of the brake pedal position sensing apparatus.
19. The brake pedal position detecting apparatus according to claim 17, further comprising:

and the third judging unit is suitable for determining that the ratio of the output voltage to the input voltage meets at least conditions that the driving mileage of the vehicle is an effective number, the driving mileage is less than or equal to a preset mileage, the ratio of the output voltage to the input voltage belongs to a preset voltage ratio range, the driving mileage of the vehicle is an effective number, the driving mileage is greater than the preset mileage, and the ratio of the output voltage to the input voltage belongs to a preset second voltage ratio range after the brake pedal assembly is assembled and the ratio of the output voltage to the input voltage of the brake pedal sensor corresponding to the brake pedal subjected to zero braking force is detected and is used as a zero-position voltage ratio P0.
20. The brake pedal position detecting apparatus according to claim 16, wherein the second calculating subunit includes:

the second detection module is suitable for detecting the ratio Pb of the output voltage and the input voltage of the corresponding brake pedal sensor when the braking force applied to the brake pedal is zero;

the second storage module is suitable for storing the ratio Pb of the voltages when the ratio Pb of the voltages meets the third storage condition;

the third counter is suitable for recording the number of the ratio Pb in the second storage module;

the second calculation module is suitable for calculating the average value Pc of the ratio Pb of the stored preset third-time threshold voltage until the third counter is continuously increased and equal to the preset third-time threshold value;

a fifth judging module, adapted to judge whether an absolute value of a difference between the average value Pc and the zero voltage ratio P0 is smaller than a preset third difference threshold;

and the fourth control module is suitable for resetting the third counter when the absolute value of the difference value between the average value Pc and the zero-position voltage ratio P0 is smaller than the third difference threshold value, and re-executing the step of detecting the ratio Pb of the output voltage and the input voltage of the brake pedal sensor corresponding to the situation that the braking force applied to the brake pedal is zero.