Vacuum pressure sensor validity checking method and system
阅读说明：本技术 真空压力传感器有效性校验方法及其系统 (Vacuum pressure sensor validity checking method and system ) 是由 黄以佳 易东旭 杨黎健 岳彬彬 伊海霞 罗宇亮 于 2020-05-22 设计创作，主要内容包括：本发明涉及真空压力传感器有效性校验方法及其系统,所述方法包括：周期性地获取主缸缸压和主缸缸压变化率,并根据所述主缸缸压和主缸缸压变化率判定驾驶员是否进行了一次有效制动动作；若驾驶员进行了一次有效制动动作,则获取本次制动过程中真空度的波动范围,并根据所述波动范围判定真空压力传感器是否卡滞；其中,若所述波动范围超过预设波动范围,则判定真空压力传感器未卡滞,若所述波动范围未超过预设波动范围,则进一步获取本次制动后有效释放制动瞬间的真空度,并根据所述真空度与所述波动范围的比较结果判定真空压力传感器是否卡滞。实施本发明,能够校验真空压力传感器是否发生了卡滞异常。(The invention relates to a method and a system for verifying the effectiveness of a vacuum pressure sensor, wherein the method comprises the following steps: periodically acquiring master cylinder pressure and master cylinder pressure change rate, and judging whether a driver performs one effective braking action according to the master cylinder pressure and the master cylinder pressure change rate; if the driver performs an effective braking action, acquiring the fluctuation range of the vacuum degree in the braking process, and judging whether the vacuum pressure sensor is stuck according to the fluctuation range; and if the fluctuation range does not exceed the preset fluctuation range, further acquiring the vacuum degree at the moment of effectively releasing the brake after the brake, and judging whether the vacuum pressure sensor is blocked or not according to the comparison result of the vacuum degree and the fluctuation range. By implementing the invention, whether the vacuum pressure sensor is in clamping stagnation abnormity can be verified.)
1. A method for verifying the validity of a vacuum pressure sensor is characterized by comprising the following steps:
periodically acquiring master cylinder pressure and master cylinder pressure change rate, and judging whether a driver performs one effective braking action according to the master cylinder pressure and the master cylinder pressure change rate;
if the driver performs an effective braking action, acquiring the fluctuation range of the vacuum degree in the braking process, and judging whether the vacuum pressure sensor is stuck according to the fluctuation range; and if the fluctuation range does not exceed the preset fluctuation range, further acquiring the vacuum degree at the moment of effectively releasing the brake after the brake, and judging whether the vacuum pressure sensor is blocked or not according to the comparison result of the vacuum degree and the fluctuation range.
2. The method for verifying the validity of the vacuum pressure sensor according to claim 1, wherein the step of determining whether the driver has performed an effective braking action according to the master cylinder pressure and the master cylinder pressure change rate specifically comprises the steps of:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
3. The vacuum pressure sensor validity checking method according to claim 1, wherein the obtaining of the vacuum degree at the moment of effective release of braking after the current braking specifically includes:
acquiring master cylinder pressure and master cylinder pressure change rate in real time;
judging whether the driver performs an action of effectively releasing the brake pedal once according to the master cylinder pressure and the master cylinder pressure change rate; if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs an effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
and if the driver performs one effective brake releasing action, acquiring the vacuum degree at the moment of effectively releasing the brake after the brake is performed.
4. The vacuum pressure sensor validity checking method according to claim 3, wherein the step of determining whether the vacuum pressure sensor is stuck according to the comparison result of the vacuum degree and the fluctuation range specifically includes:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
if the conditions are met, determining that the vacuum pressure sensor is stuck;
if the above condition is not satisfied, it is determined that the vacuum pressure sensor is not stuck.
5. The vacuum pressure sensor validity verification method of any one of claims 1 to 4, further comprising:
in the process of executing the steps, if the brake switch is turned on and the master cylinder pressure is smaller than the third pressure threshold value, or the action of releasing the brake is changed from effective to ineffective, the validity check of a new period is restarted after the preset third time is delayed and waited.
6. The vacuum pressure sensor validity verification system is characterized by comprising a brake judging unit and a verification unit;
the brake judging unit is used for periodically acquiring master cylinder pressure and master cylinder pressure change rate and judging whether a driver performs one effective brake action according to the master cylinder pressure and the master cylinder pressure change rate;
the verification unit includes:
the fluctuation range acquisition unit is used for acquiring the fluctuation range of the vacuum degree in the braking process when the driver performs an effective braking action; and
the clamping stagnation judging unit judges whether the vacuum pressure sensor is clamped or not according to the fluctuation range; the clamping stagnation determination unit comprises a first determination unit and a second determination unit, and the first determination unit is used for determining that the vacuum pressure sensor is not clamped when the fluctuation range exceeds a preset fluctuation range; and the second judging unit is used for acquiring the vacuum degree at the moment of effectively releasing the brake after the brake is performed, and judging whether the vacuum pressure sensor is stuck or not according to the comparison result of the vacuum degree and the fluctuation range when the fluctuation range does not exceed the preset fluctuation range.
7. The vacuum pressure sensor validity verification system of claim 6, wherein the brake determination unit is specifically configured to:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
8. The vacuum pressure sensor validity verification system according to claim 6, wherein the second determination unit specifically comprises:
the first signal acquisition unit is used for acquiring the master cylinder pressure and the master cylinder pressure change rate in real time;
a brake release determination unit for determining whether the driver has performed an effective brake pedal release operation based on the master cylinder pressure and the master cylinder pressure change rate; if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs an effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
the second signal acquisition unit is used for acquiring the vacuum degree of the brake moment when the brake is effectively released after the brake is performed for one time by the driver; and
and the signal processing unit is used for judging whether the vacuum pressure sensor is stuck or not according to the comparison result of the vacuum degree and the fluctuation range.
9. The vacuum pressure sensor validity verification system of claim 8, wherein the signal processing unit is specifically configured to:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
when the conditions are met, determining that the vacuum pressure sensor is stuck;
and when the conditions are not met, judging that the vacuum pressure sensor is not blocked.
10. The vacuum pressure sensor validity verification system of any one of claims 6-9, further comprising:
a delay waiting unit for generating a delay waiting signal and sending the signal to the brake judging unit when the brake switch is turned on and the master cylinder pressure is less than a third pressure threshold value or the action of releasing the brake is changed from effective to ineffective;
and the brake judging unit is also used for restarting validity check of a new period after delaying and waiting for a preset third time according to the delay waiting signal.
Technical Field
The invention relates to the technical field of vehicle control, in particular to a method and a system for verifying the effectiveness of a vacuum pressure sensor.
Background
In new energy vehicle types, because pure electric vehicle types and fuel cell vehicle types do not have engines, or hybrid vehicle types have engines but are not started in the whole running process, the electronic vacuum pump is widely used to provide a vacuum source for a vacuum boosting system. Many vacuum boosting systems often need to periodically acquire the vacuum degree of a booster through a vacuum sensor, so that the start and stop of an electric vacuum pump are determined, namely, the electric vacuum pump is started when the vacuum in the booster is insufficient, and the vacuum pump is stopped when the vacuum degree in the booster is sufficient. Therefore, if the vacuum sensor is abnormal but the abnormality is not recognized, the boosting force of the vacuum boosting system may be abnormal, and the braking capability of the vehicle may not be expected.
Most of the current electronic control units often verify the effectiveness of the vacuum pressure sensor simply, including short circuit, open circuit and short power supply of the sensor, and power supply abnormity detection of the sensor, and also include some simpler rationality verifications, such as voltage range rationality detection and the like. Although these verification methods can provide effective help under most conditions, they cannot cover all abnormal conditions. For example, an abnormal "stuck" failure of a vacuum pressure sensor: when the vacuum pressure changes, the voltage value sent by the vacuum pressure sensor does not change along with the change of the vacuum pressure, but continuously stops at a fixed voltage value. When the abnormality occurs, the abnormality cannot be detected through common validity check, and the electronic control unit can mistakenly enable the vacuum pump to work due to the abnormal value of the vacuum sensor or mistakenly and continuously disable the vacuum pump to work, so that the abnormality of the power assisting system is caused.
Disclosure of Invention
The invention aims to provide a method and a system for verifying the effectiveness of a vacuum pressure sensor so as to verify whether the vacuum pressure sensor is in clamping stagnation abnormity.
An embodiment of the present invention provides a method for verifying validity of a vacuum pressure sensor, including:
periodically acquiring master cylinder pressure and master cylinder pressure change rate, and judging whether a driver performs one effective braking action according to the master cylinder pressure and the master cylinder pressure change rate;
if the driver performs an effective braking action, acquiring the fluctuation range of the vacuum degree in the braking process, and judging whether the vacuum pressure sensor is stuck according to the fluctuation range; and if the fluctuation range does not exceed the preset fluctuation range, further acquiring the vacuum degree at the moment of effectively releasing the brake after the brake, and judging whether the vacuum pressure sensor is blocked or not according to the comparison result of the vacuum degree and the fluctuation range.
The method for determining whether the driver has performed an effective braking operation based on the master cylinder pressure and the master cylinder pressure change rate includes:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
According to the method, obtaining the vacuum degree at the moment of effectively releasing the brake after the brake, specifically comprises:
acquiring master cylinder pressure and master cylinder pressure change rate in real time;
judging whether the driver performs an action of effectively releasing the brake pedal once according to the master cylinder pressure and the master cylinder pressure change rate; if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs an effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
and if the driver performs one effective brake releasing action, acquiring the vacuum degree at the moment of effectively releasing the brake after the brake is performed.
According to the above method, wherein determining whether the vacuum pressure sensor is stuck according to the comparison result between the vacuum degree and the fluctuation range specifically includes:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
if the conditions are met, determining that the vacuum pressure sensor is stuck;
if the above condition is not satisfied, it is determined that the vacuum pressure sensor is not stuck.
The method as described above, wherein the method further comprises:
in the process of executing the steps, if the brake switch is turned on and the master cylinder pressure is smaller than the third pressure threshold value, or the action of releasing the brake is changed from effective to ineffective, the validity check of a new period is restarted after the preset third time is delayed and waited.
As the same inventive concept, the embodiment of the invention also provides a vacuum pressure sensor validity verification system, which comprises a brake determination unit and a verification unit;
the brake judging unit is used for periodically acquiring master cylinder pressure and master cylinder pressure change rate and judging whether a driver performs one effective brake action according to the master cylinder pressure and the master cylinder pressure change rate;
the verification unit includes:
the fluctuation range acquisition unit is used for acquiring the fluctuation range of the vacuum degree in the braking process when the driver performs an effective braking action; and
the clamping stagnation judging unit judges whether the vacuum pressure sensor is clamped or not according to the fluctuation range; the clamping stagnation determination unit comprises a first determination unit and a second determination unit, and the first determination unit is used for determining that the vacuum pressure sensor is not clamped when the fluctuation range exceeds a preset fluctuation range; and the second judging unit is used for acquiring the vacuum degree at the moment of effectively releasing the brake after the brake is performed, and judging whether the vacuum pressure sensor is stuck or not according to the comparison result of the vacuum degree and the fluctuation range when the fluctuation range does not exceed the preset fluctuation range.
The system according to the above, wherein the braking determination unit is specifically configured to:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
According to the above system, the second determination unit specifically includes:
the first signal acquisition unit is used for acquiring the master cylinder pressure and the master cylinder pressure change rate in real time;
a brake release determination unit for determining whether the driver has performed an effective brake pedal release operation based on the master cylinder pressure and the master cylinder pressure change rate; if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs an effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
the second signal acquisition unit is used for acquiring the vacuum degree of the brake moment when the brake is effectively released after the brake is performed for one time by the driver; and
and the signal processing unit is used for judging whether the vacuum pressure sensor is stuck or not according to the comparison result of the vacuum degree and the fluctuation range.
According to the above system, wherein the signal processing unit is specifically configured to:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
when the conditions are met, determining that the vacuum pressure sensor is stuck;
and when the conditions are not met, judging that the vacuum pressure sensor is not blocked.
The system as described above, wherein the system further comprises:
a delay waiting unit for generating a delay waiting signal and sending the signal to the brake judging unit when the brake switch is turned on and the master cylinder pressure is less than a third pressure threshold value or the action of releasing the brake is changed from effective to ineffective;
and the brake judging unit is also used for restarting validity check of a new period after delaying and waiting for a preset third time according to the delay waiting signal.
The above embodiment scheme has the following beneficial effects: the brake pedal is released by acquiring the master cylinder pressure and the master cylinder pressure change rate in the process of braking by a driver, and the brake pedal is judged according to the master cylinder pressure and the master cylinder pressure change rate and preset judgment logic, essentially according to the follow-up characteristic between the master cylinder pressure and the vacuum degree of a brake power-assisted system, when the master cylinder pressure fluctuates, whether the vacuum pressure sensor fluctuates or not is checked to judge that the clamping stagnation fails, and the technical problem of how to check whether the vacuum pressure sensor generates abnormal clamping stagnation or not is solved, so that the signal safety level of the vacuum pressure sensor is improved, and the power-assisted function safety of the vacuum power-assisted system is further improved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a flowchart illustrating a method for verifying the validity of a vacuum pressure sensor according to an embodiment of the present invention.
Fig. 2 is a block diagram of a vacuum pressure sensor validity verification system in another embodiment of the present invention.
Detailed Description
Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
In addition, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, well known means have not been described in detail so as not to obscure the present invention.
An embodiment of the present invention provides a method for checking effectiveness of a vacuum pressure sensor, fig. 1 is a flowchart of the method according to this embodiment, and the method according to this embodiment essentially determines "stuck" failure by detecting a master cylinder pressure according to a follow-up characteristic between the master cylinder pressure and a vacuum degree of a brake booster system, and checking whether the vacuum pressure sensor fluctuates when the master cylinder pressure fluctuates, referring to fig. 1, the method includes the following steps S101 to S102.
Step S101, periodically acquiring master cylinder pressure and master cylinder pressure change rate, and judging whether a driver performs one effective braking action according to the master cylinder pressure and the master cylinder pressure change rate;
specifically, the master cylinder pressure and the master cylinder pressure change rate are periodically obtained by an Electronic Control Unit (ECU) of the vehicle in the steps, and the master cylinder pressure is preferably collected once every 10ms and the master cylinder pressure change rate is calculated once every 20 ms.
Illustratively, the master cylinder pressure change rate can be subjected to low-pass filtering, and the filtering parameter can be selected to be 0.2 s.
Step S102, if the driver performs an effective braking action, acquiring a fluctuation range of the vacuum degree in the braking process, and judging whether the vacuum pressure sensor is stuck according to the fluctuation range;
and if the fluctuation range does not exceed the preset fluctuation range, further acquiring the vacuum degree at the moment of effectively releasing the brake after the brake, and judging whether the vacuum pressure sensor is blocked or not according to the comparison result of the vacuum degree and the fluctuation range.
Specifically, in the present embodiment, the fluctuation range of the vacuum degree within the latest preset time (preferably, but not limited to, 2.5s) from the determination of the effective braking timing may be (δ P)max，δPmin) Is expressed as δ PmaxIndicates the maximum vacuum degree, deltaP, in a preset timeminIndicating the minimum vacuum degree in the preset time.
Illustratively, if the fluctuation range exceeds + -7 mbar (i.e., δ P)max-δPmin14mbar) meaning that there is a fluctuation in vacuum level, there is no sticking anomaly for the vacuum pressure sensor. And if the fluctuation range does not exceed the range, the vacuum pressure sensor is possibly blocked abnormally, the vacuum degree at the moment of effectively releasing the brake after the brake is performed this time is further obtained, and whether the vacuum pressure sensor is blocked or not is judged according to the comparison result of the vacuum degree and the fluctuation range.
In a specific embodiment, the step S101 specifically includes:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
Specifically, when the driver depresses the brake pedal, the brake booster system provides vacuum boosting to the pedal, and the vacuum degree in the booster has obvious fluctuation, so that the main cylinder pressure of the brake system is increased to generate mechanical braking force. In this embodiment, the preset first time is preferably, but not limited to, 200ms, the first pressure threshold is preferably, but not limited to, 6bar, and the first rate of change threshold is preferably, but not limited to, 7 bar/s.
In a specific embodiment, the obtaining of the vacuum degree at the moment of effectively releasing the brake after the current brake in step S102 specifically includes:
step S201, after the brake, acquiring the master cylinder pressure and the master cylinder pressure change rate in real time;
step S202, judging whether the driver performs an action of effectively releasing the brake pedal or not according to the master cylinder pressure and the master cylinder pressure change rate;
if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs an effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
specifically, when the conditions 1 that the change rate of the master cylinder pressure is smaller than the second change rate threshold value and 2 that the brake switch is closed or the master cylinder pressure is larger than the second pressure threshold value are simultaneously met, it is determined that the driver performs an effective brake release action, when the driver releases the brake pedal, a front cavity and a rear cavity of the brake power assisting system are communicated, the vacuum degree also has an obvious fluctuation, meanwhile, the master cylinder pressure falls back, and the mechanical brake force disappears. In this embodiment, the preset second time is preferably, but not limited to, 120ms, the master cylinder pressure change rate is preferably, but not limited to, -11bar/s, and the second pressure threshold is preferably, but not limited to, 2 bar.
And step S203, if the driver performs an effective brake release action, acquiring the vacuum degree at the moment of effectively releasing the brake after the brake.
In an embodiment, the determining whether the vacuum pressure sensor is stuck according to the comparison result between the vacuum degree and the fluctuation range in step S102 specifically includes:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
if the conditions are met, determining that the vacuum pressure sensor is stuck;
if the above condition is not satisfied, it is determined that the vacuum pressure sensor is not stuck.
In this embodiment, the offset is preferably, but not limited to, 7 mbar.
In a specific embodiment, the method further comprises:
in the process of executing the above steps S101 to S102, if the brake switch is turned on and the master cylinder pressure is less than the third pressure threshold, or the action of releasing the brake is changed from effective to ineffective, the validity check of a new cycle is restarted after waiting for the preset third time.
Specifically, when the driver depresses and releases the brake pedal, if the depression and release speed of the brake pedal is too slow or the pedal depth is too shallow, the fluctuation of the vacuum degree is relatively small. Therefore, in order to avoid misjudgment and too frequent validity check, the embodiment screens the stepping-on and releasing brake pedals with certain depth and speed by the driver, and only when the stepping-on and releasing brake pedals are stepped on, the 'clamping stagnation' check is carried out.
The embodiment of the present invention further provides a system for checking validity of a vacuum pressure sensor, where fig. 2 is a frame diagram of the system of this embodiment, and referring to fig. 2, the system of this embodiment includes a brake determination unit 1 and a checking unit 2;
the braking determination unit 1 is used for periodically acquiring master cylinder pressure and master cylinder pressure change rate, and determining whether a driver performs an effective braking action according to the master cylinder pressure and the master cylinder pressure change rate;
the verification unit 2 includes:
a fluctuation range acquisition unit 21 configured to acquire a fluctuation range of the vacuum degree in the current braking process when the driver performs an effective braking action; and
a sticking determination unit 22 that determines whether the vacuum pressure sensor is stuck or not based on the fluctuation range; the stagnation determination unit comprises a first determination unit 221 and a second determination unit 222, wherein the first determination unit 221 is used for determining that the vacuum pressure sensor is not clamped when the fluctuation range exceeds a preset fluctuation range; the second determining unit 222 is configured to, when the fluctuation range does not exceed the preset fluctuation range, obtain a vacuum degree at the instant when the brake is effectively released after the brake is performed this time, and determine whether the vacuum pressure sensor is stuck according to a comparison result between the vacuum degree and the fluctuation range.
In a specific embodiment, the brake determination unit 1 is specifically configured to:
if the first time is continuously preset, the master cylinder pressure is greater than a first pressure threshold value, and the master cylinder pressure change rate is greater than or equal to a first change rate threshold value, judging that the driver performs an effective braking action; otherwise, the driver is judged not to perform effective braking action.
In an embodiment, the second determining unit 222 specifically includes:
the first signal acquisition unit is used for acquiring the master cylinder pressure and the master cylinder pressure change rate in real time;
a brake release determination unit for determining whether the driver has performed an effective brake pedal release operation based on the master cylinder pressure and the master cylinder pressure change rate; if the second time is continuously preset, the change rate of the master cylinder pressure is smaller than a second change rate threshold value, and the brake switch is closed or the master cylinder pressure is larger than a second pressure threshold value, it is judged that the driver performs one effective brake release action; otherwise, judging that the driver does not perform effective brake releasing action;
the second signal acquisition unit is used for acquiring the vacuum degree of the brake moment when the brake is effectively released after the brake is performed for one time by the driver; and
and the signal processing unit is used for judging whether the vacuum pressure sensor is stuck or not according to the comparison result of the vacuum degree and the fluctuation range.
In a specific embodiment, the signal processing unit is specifically configured to:
judging whether the vacuum degree and the fluctuation range meet the following conditions:
δPmax–offset≤Prelease≤δPmin+offset
wherein, PreleaseThe offset is a preset vacuum degree delta P for effectively releasing the instant vacuum degree of the brake in the brake processmaxMaximum vacuum degree, deltaP, of said fluctuation rangeminThe minimum vacuum degree of the fluctuation range;
when the conditions are met, determining that the vacuum pressure sensor is stuck;
and when the conditions are not met, judging that the vacuum pressure sensor is not blocked.
In a specific embodiment, the system further comprises:
a delay waiting unit 3 for generating a delay waiting signal and transmitting the signal to the brake determination unit 1 when the brake switch is turned on and the master cylinder pressure is less than the third pressure threshold value or the action of releasing the brake is changed from effective to ineffective;
the braking determination unit 1 is further configured to restart validity checking of a new period after waiting for a preset third time in a delayed manner according to the delayed waiting signal.
The above-described system embodiments are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.
It should be noted that the system described in the foregoing embodiment corresponds to the method described in the foregoing embodiment, and therefore, portions of the system described in the foregoing embodiment that are not described in detail can be obtained by referring to the content of the method described in the foregoing embodiment, and details are not described here.
Furthermore, the validity check system for the vacuum pressure sensor according to the above embodiments may be stored in a computer-readable storage medium if it is implemented in the form of a software functional unit and sold or used as a stand-alone product.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.