CN113898468B - Fault diagnosis method and device for auxiliary braking system - Google Patents
Fault diagnosis method and device for auxiliary braking system Download PDFInfo
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- CN113898468B CN113898468B CN202111203158.5A CN202111203158A CN113898468B CN 113898468 B CN113898468 B CN 113898468B CN 202111203158 A CN202111203158 A CN 202111203158A CN 113898468 B CN113898468 B CN 113898468B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B77/00—Component parts, details or accessories, not otherwise provided for
- F02B77/08—Safety, indicating or supervising devices
- F02B77/083—Safety, indicating or supervising devices relating to maintenance, e.g. diagnostic device
Abstract
The application provides a fault diagnosis method and a fault diagnosis device for an auxiliary braking system, wherein the method comprises the following steps: determining whether the auxiliary braking system has electrical faults or not according to the relevant fault parameters of the auxiliary braking system, if not, determining whether the auxiliary braking system is in a service test mode, if so, adjusting an idle speed set value of the engine, opening an auxiliary braking electromagnetic valve and a throttle valve, determining whether the auxiliary braking system has non-electrical faults or not according to first free fall time of the rotating speed of the engine under the first braking action, if not, detecting whether a driving state parameter of the auxiliary braking electromagnetic valve and a neutral state parameter are both set, and if so, determining whether the auxiliary braking system has non-electrical faults or not according to second free fall time of the rotating speed of the engine under the second braking action. Through the application, whether the auxiliary braking system has a non-electric fault or not can be diagnosed.
Description
Technical Field
The application relates to the technical field of engines, in particular to a fault diagnosis method and device for an auxiliary braking system.
Background
The auxiliary brake system commonly used for the engine body mainly comprises exhaust brake, in-cylinder brake and the like, wherein non-electrical faults, such as non-electrical faults of an exhaust brake solenoid valve, mechanical faults of an exhaust brake butterfly valve and the like, frequently occur in the actual use process of the auxiliary brake system, and the occurrence of the faults can cause the auxiliary brake of the engine to be abnormal, so that the problems of insufficient power, poor economy, poor brake effect and the like of the engine are caused, and the use of a user is seriously influenced. Such non-electrical faults cannot be found and handled in advance because an engine electronic control system (ECU) cannot directly diagnose the non-electrical faults.
In summary, there is a need for a method for diagnosing faults of an auxiliary braking system, so as to find out faults of non-electrical devices in the auxiliary braking system in time.
Disclosure of Invention
In view of this, the present application provides a method and a device for diagnosing a fault of an auxiliary braking system, which are used for diagnosing a fault of the auxiliary braking system, and the technical scheme is as follows:
an auxiliary brake system fault diagnosis method comprising:
determining whether the auxiliary braking system has electrical faults or not according to the relevant fault parameters of the auxiliary braking system;
if the auxiliary braking system has no electric appliance faults, determining whether the auxiliary braking system is in a service test mode;
if the auxiliary braking system is in the service test mode, the rotation speed of the engine is enabled to fall back freely under the first braking action by adjusting the idle speed set value of the engine and opening the auxiliary braking electromagnetic valve and the throttle valve, and whether the auxiliary braking system has non-electrical equipment faults or not is determined according to the first free fall time of the rotation speed of the engine under the first braking action;
and if the auxiliary brake system is not in the service test mode, detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake electromagnetic valve are both set, and if so, determining whether the auxiliary brake system has non-electrical faults or not according to the second free fall time of the rotating speed of the engine under the second brake action.
Optionally, determining whether the auxiliary braking system has an electrical fault according to the relevant fault parameter of the auxiliary braking system, including:
if the relevant fault parameters of the auxiliary braking system are not set, determining that the auxiliary braking system has no electric appliance fault;
and if the relevant fault parameters of the auxiliary braking system are set, determining that the auxiliary braking system has an electrical fault.
Optionally, the method includes the steps of adjusting an idle speed set value of the engine, and opening an auxiliary braking solenoid valve and a throttle valve to enable the rotation speed of the engine to freely fall back under the first braking action, and the method includes the following steps:
starting the engine, and increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed;
and restoring the idle speed set value of the engine to a normal idle speed value, and opening an auxiliary brake solenoid valve and a throttle valve to enable the rotating speed of the engine to freely fall back under the action of a first brake.
Optionally, the first free fall time is a time when the rotation speed of the engine is reduced from the target rotation speed to a preset rotation speed, and the preset rotation speed is greater than or equal to a normal idle speed value;
determining whether the auxiliary braking system has a non-electrical fault according to a first free fall time of the rotating speed of the engine under the action of first braking, wherein the method comprises the following steps:
determining a difference value between the target rotating speed and a preset rotating speed as a first difference value;
determining a total intake air flow rate of a cylinder of the engine during a first free fall time as a first intake air flow rate;
determining a first preset threshold value according to the first difference value and the first intake air flow;
and determining whether the auxiliary braking system has a non-electrical fault according to the first free fall time and a first preset threshold value.
Optionally, determining whether the auxiliary braking system has a non-electrical fault according to the first free fall time and the first preset threshold, including:
if the first free fall time is larger than or equal to a first preset threshold value, determining that the auxiliary braking system has non-electrical faults;
and if the first free fall time is less than a first preset threshold value, determining that the auxiliary braking system has no non-electrical faults.
Optionally, before starting the engine and increasing the idle speed set value of the engine from the normal idle speed value to the target speed, the method further includes:
and detecting the speed of the whole vehicle, starting the engine when detecting that the speed of the whole vehicle is 0, and increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed.
Optionally, after detecting that the driving state parameter and the neutral state parameter of the auxiliary brake solenoid valve are both set, before determining whether the auxiliary brake system has a non-electrical fault according to a second free fall time of the rotation speed of the engine under a second braking action, the method further includes:
detecting whether the driving state parameter of the auxiliary braking electromagnetic valve is reset or not;
and if the driving state parameter of the auxiliary brake electromagnetic valve is reset, taking the time from setting to resetting of the driving state parameter of the auxiliary brake electromagnetic valve as second free fall time.
Optionally, determining whether the auxiliary braking system has a non-electrical fault according to a second free fall time of the rotation speed of the engine under the action of the second brake, including:
determining an engine speed difference value corresponding to the resetting of the auxiliary brake electromagnetic valve driving state parameter from the set value as a second difference value;
determining a total intake air flow rate of a cylinder of the engine during a second free fall time as a second intake air flow rate;
determining a second preset threshold value according to the second difference value and the second air intake flow;
and determining whether the auxiliary braking system has non-electrical faults or not according to the second free fall time and a second preset threshold value.
Optionally, determining whether the auxiliary braking system has a non-electrical fault according to the second free fall time and a second preset threshold, including:
if the second free fall time is greater than or equal to a second preset threshold value, determining that the auxiliary braking system has a non-electrical fault;
and if the second free fall time is less than a second preset threshold value, determining that the auxiliary braking system has no non-electrical faults.
An auxiliary brake system fault diagnosis device comprising: the device comprises an electric appliance fault judgment module, a service test mode judgment module, a first fault diagnosis module and a second fault diagnosis module;
the electric appliance fault judging module is used for determining whether the auxiliary braking system has electric appliance faults or not according to the relevant fault parameters of the auxiliary braking system;
the service test mode judging module is used for determining whether the auxiliary braking system is in a service test mode or not if the auxiliary braking system does not have electrical faults;
the first fault diagnosis module is used for adjusting an idle speed set value of the engine and opening an auxiliary braking electromagnetic valve and a throttle valve to enable the rotating speed of the engine to freely fall back under the first braking action if the service test mode judgment module determines that the service test mode is in, and determining whether the auxiliary braking system has non-electrical equipment faults or not according to the first free fall-back time of the rotating speed of the engine under the first braking action;
and the second fault diagnosis module is used for detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake solenoid valve are both set or not if the service test mode judgment module determines that the auxiliary brake solenoid valve is not in the service test mode, and determining whether the auxiliary brake system has non-electrical equipment faults or not according to the second free fall time of the rotating speed of the engine under the second brake action if the auxiliary brake solenoid valve is in the neutral state parameter.
According to the technical scheme, whether the auxiliary braking system has an electrical fault or not is determined according to relevant fault parameters of the auxiliary braking system, if the auxiliary braking system does not have the electrical fault, whether the auxiliary braking system is in a service test mode or not is determined, if the auxiliary braking system is in the service test mode, the idle speed set value of the engine is adjusted, the auxiliary braking electromagnetic valve and the throttle valve are opened, the rotating speed of the engine freely falls under the first braking action, whether the auxiliary braking system has a non-electrical fault or not is determined according to the first free falling time of the rotating speed of the engine under the first braking action, if the auxiliary braking system is not in the service test mode, whether the driving state parameter and the neutral state parameter of the auxiliary braking electromagnetic valve are set or not is detected, and if the auxiliary braking system has the non-electrical fault or not is determined according to the second free falling time of the rotating speed of the engine under the second braking action. According to the auxiliary braking system fault diagnosis method, whether the auxiliary braking system has the non-electrical faults or not can be diagnosed in the service test mode and the non-service test mode, and the auxiliary braking system fault diagnosis method does not need to add a sensor and an actuator, so that diagnosis cost is low.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only the embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic flow chart illustrating a first method for diagnosing a fault of an auxiliary braking system according to an embodiment of the present disclosure;
FIG. 2 is a schematic flow chart illustrating a non-electrical fault diagnosis of the auxiliary braking system in the service test mode according to the embodiment of the present disclosure;
fig. 3 is a schematic flow chart illustrating non-electrical fault diagnosis performed on an auxiliary braking system in a normal operation process of a finished automobile according to the embodiment of the present application;
fig. 4 is a schematic structural diagram of an auxiliary brake system fault diagnosis device provided in an embodiment of the present application;
fig. 5 is a hardware block diagram of an auxiliary brake system fault diagnosis device according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
The auxiliary braking system may have electrical faults as well as non-electrical faults during actual use. Here, the electrical faults refer to faults that can be directly diagnosed by the ECU (engine electronic control system), for example, faults such as open circuit, short circuit to ground, short circuit to power supply, and the like, and the non-electrical faults refer to faults that cannot be directly diagnosed by the ECU (engine electronic control system), for example, non-electrical faults such as clamping stagnation, aging, and inflexibility of the exhaust brake butterfly valve in the exhaust brake system. The auxiliary braking of the engine is abnormal due to the occurrence of the non-electrical faults, and the ECU cannot directly diagnose the non-electrical faults, so that the non-electrical faults cannot be found and repaired in time, the problems of insufficient power, poor economy, poor braking effect and the like of the engine are caused, and the use of a user is seriously influenced.
In view of the problems in the prior art, the inventor of the present invention has conducted extensive research, and then has conceived that, on the premise that no electrical fault exists in an actual auxiliary braking system, whether a non-electrical fault exists in the auxiliary braking system can be determined by comparing an actual downward trend of an engine speed in the auxiliary braking system with a downward trend of a speed in a normal braking system, and meanwhile, related factors influencing the downward trend of the engine speed need to be considered, so as to improve accuracy of fault diagnosis.
Based on this, the inventor proposes an auxiliary brake system fault diagnosis method, and the following embodiments will describe the auxiliary brake system fault diagnosis method provided in the present application in detail.
Referring to fig. 1, a schematic flowchart of a method for diagnosing a fault of an auxiliary braking system according to an embodiment of the present application is shown, where the method for diagnosing a fault of an auxiliary braking system may include:
and S101, determining whether the auxiliary braking system has electrical faults or not according to the relevant fault parameters of the auxiliary braking system.
Specifically, in this embodiment, when the auxiliary braking system does not have an electrical fault, the non-electrical fault diagnosis needs to be performed on the auxiliary braking system. The auxiliary brake system refers to an auxiliary brake system to be subjected to non-electrical fault diagnosis.
Optionally, in this step, it may be determined whether an electrical fault exists in the auxiliary braking system according to a relevant fault parameter of the auxiliary braking system, specifically, if the relevant fault parameter of the auxiliary braking system is not set, it is determined that the electrical fault does not exist in the auxiliary braking system, and if the relevant fault parameter of the auxiliary braking system is set, it is determined that the electrical fault exists in the auxiliary braking system.
And S102, if the auxiliary braking system has no electrical faults, determining whether the auxiliary braking system is in a service test mode.
In this embodiment, when the entire vehicle is in the service test mode and is not in the service test mode, the non-electrical fault diagnosis may be performed on the auxiliary braking system, so that when it is determined that the auxiliary braking system has no electrical fault, it is further determined whether the auxiliary braking system is in the service test mode.
Alternatively, this step may determine whether to be in the service test mode by obtaining an auxiliary brake system service test request status parameter indicating whether to be in the service test mode. If the service test request state parameter of the auxiliary brake system is not set, the auxiliary brake system is determined not to be in the service test mode.
And step S103, if the auxiliary braking system is in the service test mode, adjusting an idle speed set value of the engine, opening an auxiliary braking electromagnetic valve and a throttle valve to enable the rotating speed of the engine to freely fall back under the first braking action, and determining whether the auxiliary braking system has non-electrical faults or not according to the first free fall time of the rotating speed of the engine under the first braking action.
The method comprises the step of carrying out non-electrical fault diagnosis on the auxiliary braking system when the whole vehicle is in a service test mode. In the service test mode, the vehicle is not moved in place, the engine is disconnected with the transmission system, at the moment, the idle speed set value of the engine can be adjusted, the auxiliary brake electromagnetic valve and the throttle valve are opened, the rotating speed of the engine freely falls under the first brake action, and then whether non-electrical equipment faults exist in the auxiliary brake system or not is determined according to the first free falling time of the rotating speed of the engine under the first brake action. Here, the first free fall time may reflect an actual downward tendency of the engine speed under the first braking action.
Here, the idle speed setting value is an engine speed value corresponding to no-gear-shifting without stepping on an accelerator in a vehicle-in-place state, the opening degree of the auxiliary brake solenoid valve may be used to determine the magnitude of the braking action, and both the opening degree of the auxiliary brake solenoid valve and the opening degree of the throttle valve may be used to control the intake air flow rate in the cylinder of the engine.
And step S104, if the auxiliary brake system is not in the service test mode, detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake electromagnetic valve are both set, and if so, determining whether the auxiliary brake system has non-electrical equipment faults or not according to the second free fall-back time of the rotating speed of the engine under the second brake action.
Specifically, if the vehicle is not in the service test mode, the whole vehicle is represented to be in a normal operation state, and then the step can be used for carrying out non-electrical fault diagnosis on the auxiliary braking system in the normal operation process of the whole vehicle.
In this step, when it is determined that the auxiliary brake solenoid valve is not in the service test mode, it may be detected whether the driving state of the auxiliary brake solenoid valve is set, and if the driving state of the auxiliary brake solenoid valve is set, it may be detected whether the neutral state is set, and if the driving state parameter of the auxiliary brake solenoid valve and the neutral state parameter are set, the rotation speed of the engine may fall back freely under the second braking action, and then it may be determined whether the non-electrical equipment fault exists in the auxiliary brake system according to the second free fall time of the rotation speed of the engine under the second braking action. Here, the second free fall time may reflect an actual downward tendency of the engine speed under the second braking action.
In this step, the driving state setting of the auxiliary brake solenoid valve represents that the auxiliary brake is opened, at this time, the rotation speed of the engine is reduced under the braking action, the driving state resetting of the auxiliary brake solenoid valve represents that the auxiliary brake is closed, and the rotation speed of the engine is not influenced by the braking action any more.
Optionally, the setting and resetting of the driving state parameter of the auxiliary brake solenoid valve includes, but is not limited to, the following scenarios: the driver actively starts the auxiliary brake (for example, the auxiliary brake may be used in the whole vehicle running process, and the driver can actively start the auxiliary brake at the moment), so that the driving state parameter of the auxiliary brake electromagnetic valve is set; and when the rotating speed of the engine is lower than a certain threshold value, the driving state parameter of the auxiliary brake electromagnetic valve can be automatically reset.
In this step, the setting of the neutral state parameter indicates that the engine is in a neutral state. The reason why the engine in this embodiment needs to be in the neutral state is that: when the engine is in a non-neutral state, the whole vehicle is connected with a transmission shaft, wheels and the like, frictional resistance is generated, and at the moment, after the auxiliary brake is started, whether the rotating speed of the engine is reduced due to the auxiliary brake or the frictional resistance cannot be determined. Therefore, in order to prevent the influence of factors such as a transmission system and road conditions on the rotating speed descending trend of the engine after the auxiliary brake is started under the condition that the whole vehicle is in a gear shift, the whole vehicle is required to be in a transmission system disconnection working condition, namely, the engine is in a neutral position state.
The method for diagnosing the faults of the auxiliary braking system comprises the steps of firstly determining whether the auxiliary braking system has electrical faults or not, determining whether the auxiliary braking system is in a service test mode or not if the auxiliary braking system does not have the electrical faults or not, determining whether the auxiliary braking system has non-electrical faults or not by adjusting an idle speed set value of an engine and opening an auxiliary braking electromagnetic valve and a throttle valve if the auxiliary braking system is in the service test mode, enabling the rotating speed of the engine to freely fall back under the action of first braking, determining whether the auxiliary braking system has the non-electrical faults or not according to the first free falling time of the rotating speed of the engine under the action of the first braking, detecting whether driving state parameters and neutral state parameters of the auxiliary braking electromagnetic valve are both set or not if the auxiliary braking system is not in the service test mode, and determining whether the auxiliary braking system has the non-electrical faults or not according to the second free falling time of the rotating speed of the engine under the action of the second braking if the auxiliary braking system is not in the service test mode. According to the auxiliary braking system fault diagnosis method, whether the auxiliary braking system has the non-electrical faults or not can be diagnosed in the service test mode and the non-service test mode, and the auxiliary braking system fault diagnosis method does not need to add a sensor and an actuator, so that diagnosis cost is low.
In order to make those skilled in the art understand the present solution more, the following two embodiments respectively describe the processes of step S103 and step S104 in detail.
In an alternative embodiment, the present embodiment describes the process of step S103. In step S103, when the entire vehicle is in the service test mode, the non-electrical fault that cannot be directly diagnosed by the ECU may be pre-diagnosed.
Please refer to fig. 2, which is a schematic flow chart illustrating a non-electrical fault diagnosis of the auxiliary braking system in the service test mode according to the embodiment of the present application.
Alternatively, the process of "making the engine speed drop freely under the braking action by adjusting the idle speed set value of the engine and opening the auxiliary braking solenoid valve and the throttle valve" in the step S103 may include the following steps S201 to S202:
and step S201, starting the engine, and increasing the idling set value of the engine from the normal idling value to the target rotating speed.
Specifically, in the service test mode, the vehicle is not moved on site, the engine is disconnected from the drive train, and the idle speed set value of the engine can be increased from the normal idle speed value to the target rotating speed after the engine is started.
For example, if the normal idle speed is 650rpm, the step may increase the idle speed setting of the engine from 650rpm to 2000rpm.
In an optional embodiment, in order to perform non-electrical fault diagnosis on the auxiliary brake system more safely in the service test mode, in this embodiment, when it is determined that the auxiliary brake system is in the service test mode, the vehicle speed of the entire vehicle is detected, when it is detected that the vehicle speed of the entire vehicle is 0, the engine is started again, the idle speed set value of the engine is increased from the normal idle speed value to the target speed, and if it is detected that the vehicle speed of the entire vehicle is not 0, whether the auxiliary brake system is in the service test mode is determined again until it is determined that the auxiliary brake system is in the service test mode, and when the vehicle speed of the entire vehicle is 0, the engine is started again, and the idle speed set value of the engine is increased from the normal idle speed value to the target speed.
And S202, restoring the idling set value of the engine to a normal idling value, and opening an auxiliary brake electromagnetic valve and a throttle valve to enable the rotating speed of the engine to freely fall back under the first brake action.
In this step, after the rotation speed of the engine is increased to the target rotation speed, the set time is maintained, and then the idle speed set value of the engine is restored to the normal idle speed value, at this time, the rotation speed of the engine can freely fall back.
In order to determine whether the auxiliary braking system has a non-electrical fault, it is necessary to determine a free fall situation of the engine speed under the braking action, therefore, this step needs to open the auxiliary braking solenoid valve and a throttle valve (alternatively, the throttle valve may also be a throttle valve) on the air intake path while returning the idle speed set value of the engine to the normal idle speed value, so as to make the engine speed fall freely under the first braking action.
And step S203, taking the time for the rotating speed of the engine to be reduced from the target rotating speed to the preset rotating speed as a first free fall time.
Alternatively, in addition to the above steps S201 to S202, the "free fall time of the engine speed under the first braking action" in the above step S103 may be a time when the engine speed is reduced from the target speed to the preset speed under the first braking action corresponding to the auxiliary braking system.
Optionally, in view of that the auxiliary brake is automatically exited after the rotation speed of the engine is lower than a certain value, so as not to generate a braking effect any more, in order to more accurately determine whether the auxiliary brake system has a non-electrical fault, the preset rotation speed may be a value greater than a normal idle speed value, for example, the normal idle speed value is 650rpm, and the preset rotation speed may be 1200rpm.
Of course, in some scenarios, the preset rotation speed may also be equal to the normal idle speed value.
Based on this, the process of determining whether the auxiliary braking system has the non-electrical fault according to the first free fall time of the engine speed under the first braking action in the step S103 may include the following steps S204 to S207:
and step S204, determining the difference value between the target rotating speed and the preset rotating speed as a first difference value.
For example, if the target rotation speed is 2000rpm and the preset rotation speed is 1200rpm, the first difference is 800rpm.
In step S205, the total intake air flow rate of the cylinders of the engine in the first free fall time is determined as the first intake air flow rate.
After intensive research, the inventor finds that braking effects at different intake air flow rates after the auxiliary brake is turned on are different, and therefore, the present embodiment needs to consider the influence of the intake air flow rate on a first preset threshold value described below.
Alternatively, the process of determining the total intake air flow rate in the first free fall time in the cylinder of the engine of the present step may include: an integrated value of the intake air flow rate in the first free fall time is calculated, which is the first intake air flow rate.
And S206, determining a first preset threshold value according to the first difference value and the first intake air flow.
Optionally, in consideration of differences in braking effects under different intake air flow rates, in this step, a mapping relationship between the difference value, the intake air flow rate, and the first preset threshold may be pre-constructed, so that when the first difference value and the first intake air flow rate are obtained, the first preset threshold is determined according to the first difference value and the first intake air flow rate, and the pre-established mapping relationship between the difference value, the intake air flow rate, and the first preset threshold.
And step S207, determining whether the auxiliary braking system has a non-electrical fault or not according to the first free fall time and a first preset threshold value.
In this step, a first free fall time of the rotation speed of the engine under the first braking action may be determined, and then, according to the determined first free fall time and a first preset threshold, it may be determined whether a non-electrical fault exists in the auxiliary braking system. If the first free fall time of the rotating speed of the engine under the first braking action is greater than or equal to a first preset threshold value, it is determined that the auxiliary braking system has non-electrical faults, and if the first free fall time of the rotating speed of the engine under the first braking action is smaller than the first preset threshold value, it is determined that the auxiliary braking system does not have the non-electrical faults.
Optionally, in this step, when it is determined that the auxiliary braking system has a non-electrical fault, an abnormal fault of the auxiliary braking system may be reported, and a user is prompted to perform maintenance, so as to avoid the problems of insufficient engine power, poor economy, poor braking effect, and the like.
According to the embodiment of the application, whether the auxiliary braking system has the non-electrical faults or not can be diagnosed when the whole vehicle is in the service test mode, and the diagnosis cost is low without adding a sensor and an actuator.
In another alternative embodiment, the present embodiment describes the process of step S104. In step S104, when the entire vehicle is not in the service test mode, the non-electrical faults that cannot be directly diagnosed by the ECU are pre-diagnosed, that is, the non-electrical faults of the auxiliary braking system are diagnosed in the normal operation process of the entire vehicle.
Please refer to fig. 3, which is a schematic flow chart illustrating a non-electrical fault diagnosis performed on an auxiliary braking system during a normal operation of a vehicle according to an embodiment of the present disclosure.
Optionally, the process of diagnosing the non-electrical fault of the auxiliary braking system during the normal operation of the entire vehicle may include the following steps S301 to S307:
and S301, detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake electromagnetic valve are both set.
Specifically, the method comprises the steps of firstly detecting whether a driving state parameter of an auxiliary brake electromagnetic valve is set or not so as to determine whether to start auxiliary braking or not.
If the driving state parameter of the auxiliary brake solenoid valve is set, the characteristic that the auxiliary brake is started is represented, and whether the neutral state parameter is set or not can be detected at the moment, so that whether the engine is in the neutral state or not can be determined.
And S302, if the driving state parameter of the auxiliary brake solenoid valve and the neutral gear state parameter are set, detecting whether the driving state parameter of the auxiliary brake solenoid valve is reset or not.
And step S303, if the driving state parameter of the auxiliary brake electromagnetic valve is reset, taking the time from setting to resetting of the driving state parameter of the auxiliary brake electromagnetic valve as a second free fall time.
After the driving state parameter of the auxiliary braking electromagnetic valve and the neutral gear state parameter are both set, the rotating speed of the engine can freely fall back under the second braking action.
Based on this, the process of determining whether the auxiliary braking system has the non-electrical fault according to the second free fall time of the rotation speed of the engine under the second braking action in the step S104 may include the following steps S304 to S307:
and S304, determining the engine speed difference value corresponding to the resetting of the auxiliary brake electromagnetic valve driving state parameter from the set value to the resetting as a second difference value.
In this step, the rotation speed of the engine can freely fall back under the second braking action within the time (i.e., the second free fall time) from the setting to the resetting of the driving state parameter of the auxiliary braking solenoid valve, so the rotation speed of the engine during the setting and the rotation speed of the engine during the resetting of the driving state parameter of the auxiliary braking solenoid valve can be respectively determined in this step, and the second difference can be obtained by calculating the difference between the rotation speeds of the two engines.
Step S305, determining the total intake air flow rate of the cylinder of the engine in the second free fall time as a second intake air flow rate.
Alternatively, the present step may obtain the second intake air flow rate by calculating the integrated value of the intake air flow rate in the second free fall time, corresponding to step S204 described above.
And S306, determining a second preset threshold according to the second difference and the second air inflow.
Optionally, in consideration of differences in braking effects under different intake air flows, a mapping relationship between the difference, the intake air flow and the second preset threshold may be pre-constructed in this step, so that when the second difference and the second intake air flow are obtained, the second preset threshold is determined according to the second difference and the second intake air flow, and the pre-established mapping relationship between the difference, the intake air flow and the second preset threshold.
And step S307, determining whether the auxiliary braking system has non-electrical faults or not according to the second free fall time and a second preset threshold value.
In this step, a second free fall time of the rotation speed of the engine under the second braking action may be determined, and then, according to the second free fall time and a second preset threshold, it may be determined whether the auxiliary braking system has a non-electrical fault. If the second free fall time is greater than or equal to a second preset threshold, it is determined that the auxiliary braking system has a non-electrical fault, and if the second free fall time is less than the second preset threshold, it is determined that the auxiliary braking system does not have the non-electrical fault.
Optionally, in this step, when it is determined that the auxiliary braking system has a non-electrical fault, an abnormal fault of the auxiliary braking system may be reported, and a user is prompted to perform maintenance, so as to avoid the problems of insufficient engine power, poor economy, poor braking effect, and the like.
According to the embodiment of the application, whether the auxiliary braking system has the non-electrical faults or not can be diagnosed when the whole vehicle is not in the service test mode, namely whether the auxiliary braking system has the non-electrical faults or not can be diagnosed in the normal running process of the whole vehicle.
The embodiment of the present application further provides an auxiliary braking system fault diagnosis device, which is described below, and the auxiliary braking system fault diagnosis device described below and the auxiliary braking system fault diagnosis method described above may be referred to correspondingly.
Referring to fig. 4, a schematic structural diagram of an auxiliary brake system fault diagnosis device according to an embodiment of the present application is shown, and as shown in fig. 4, the auxiliary brake system fault diagnosis device may include: an electrical appliance fault judgment module 401, a service test mode judgment module 402, a first fault diagnosis module 403 and a second fault diagnosis module 404.
And an electrical fault judging module 401, configured to determine whether an electrical fault exists in the auxiliary braking system according to the relevant fault parameter of the auxiliary braking system.
A service test mode determining module 402, configured to determine whether the auxiliary braking system is in the service test mode if the auxiliary braking system has no electrical fault.
And a first fault diagnosis module 403, configured to, if the service test mode determination module determines that the service test mode is set, adjust an idle speed set value of the engine, and open the auxiliary brake solenoid valve and the throttle valve, so that the rotation speed of the engine freely falls back under the first braking action, and determine whether the auxiliary brake system has a non-electrical fault according to a first free fall time of the rotation speed of the engine under the first braking action.
And a second fault diagnosis module 404, configured to detect whether the driving state parameter and the neutral state parameter of the auxiliary brake solenoid valve are both set if the service test mode determination module determines that the auxiliary brake solenoid valve is not in the service test mode, and determine whether the auxiliary brake system has a non-electrical fault according to a second free fall time of the rotation speed of the engine under a second braking action if the driving state parameter and the neutral state parameter are both set.
The auxiliary braking system fault diagnosis device provided by the embodiment of the application determines whether the auxiliary braking system has an electrical fault according to relevant fault parameters of the auxiliary braking system, determines whether the auxiliary braking system is in a service test mode if the auxiliary braking system has no electrical fault, determines whether the auxiliary braking system has a non-electrical fault by adjusting an idle speed set value of an engine and opening an auxiliary braking electromagnetic valve and a throttle valve if the auxiliary braking system is in the service test mode, so that the rotating speed of the engine freely falls under a first braking action, determines whether the auxiliary braking system has the non-electrical fault according to first free falling time of the rotating speed of the engine under the first braking action, detects whether a driving state parameter and a neutral state parameter of the auxiliary braking electromagnetic valve are both set if the auxiliary braking electromagnetic valve is not in the service test mode, and determines whether the auxiliary braking system has the non-electrical fault according to second free falling time of the rotating speed of the engine under a second braking action if the auxiliary braking system is not in the service test mode. The auxiliary braking system fault diagnosis device provided by the application can be used for diagnosing whether the auxiliary braking system has non-electrical faults or not in a service test mode and a non-service test mode, and is low in diagnosis cost without adding a sensor and an actuator.
In a possible implementation manner, the electrical fault determining module 401 may specifically be configured to: and if the relevant fault parameters of the auxiliary braking system are not set, determining that the auxiliary braking system has no electric appliance faults, and if the relevant fault parameters of the auxiliary braking system are set, determining that the auxiliary braking system has electric appliance faults.
In one possible implementation, the first fault diagnosis module 403 may include, when the engine speed is allowed to fall back freely under the first braking action by adjusting an idle speed set value of the engine and opening the auxiliary braking solenoid valve and the throttle valve: the device comprises an idle speed set value increasing module and a rotating speed falling control module.
The idle speed set value increasing module is used for starting the engine and increasing the idle speed set value of the engine from a normal idle speed value to a target rotating speed.
And the rotating speed drop control module is used for recovering the idling set value of the engine to a normal idling value and opening the auxiliary brake solenoid valve and the throttle valve so as to enable the rotating speed of the engine to drop freely under the first brake action.
In a possible implementation manner, the first free fall time is a time when the rotating speed of the engine is reduced from a target rotating speed to a preset rotating speed, and the preset rotating speed is greater than or equal to a normal idle speed value;
when determining whether the non-electrical fault exists in the auxiliary braking system according to the first free fall time of the rotation speed of the engine under the first braking action, the first fault diagnosis module 403 may include: the device comprises a first difference value determining module, a first intake air flow determining module, a first preset threshold determining module and a first fault diagnosis submodule.
The first difference determining module is used for determining a difference between the target rotating speed and a preset rotating speed as a first difference.
The first intake air flow determination module is configured to determine a total intake air flow in a first free fall time of a cylinder of the engine as a first intake air flow.
And the first preset threshold determining module is used for determining a first preset threshold according to the first difference and the first intake air flow.
And the first fault diagnosis submodule is used for determining whether the auxiliary braking system has non-electrical faults or not according to the first free fall time and the first preset threshold value.
In a possible implementation manner, the first fault diagnosis sub-module may be specifically configured to determine that the auxiliary braking system has a non-electrical fault if the first free fall time is greater than or equal to a first preset threshold, and determine that the auxiliary braking system does not have the non-electrical fault if the first free fall time is less than the first preset threshold.
In a possible implementation manner, before the idle speed set value increasing module, the auxiliary braking system fault diagnosis device provided by the present application may further include: and a vehicle speed detection module.
The vehicle speed detection module is used for detecting the vehicle speed of the whole vehicle, starting the engine when the vehicle speed of the whole vehicle is detected to be 0, and increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed.
In a possible implementation manner, the second fault diagnosis module 404 may be further configured to: and detecting whether the driving state parameter of the auxiliary brake solenoid valve is reset or not after detecting that the driving state parameter of the auxiliary brake solenoid valve and the neutral state parameter are both set, if the driving state parameter of the auxiliary brake solenoid valve is reset, taking the time from the set state to the reset state of the driving state parameter of the auxiliary brake solenoid valve as second free fall-back time, and determining whether the auxiliary brake system has non-electrical faults or not according to the second free fall-back time of the rotating speed of the engine under the action of second braking.
In a possible implementation manner, when determining whether the non-electrical fault exists in the auxiliary braking system according to the second free fall time of the rotation speed of the engine under the second braking action, the second fault diagnosis module 404 may include: the second difference determining module, the second air inflow determining module, the second preset threshold determining module and the second fault diagnosis submodule.
And the second difference determining module is used for determining the engine speed difference corresponding to the setting to the resetting of the driving state parameter of the auxiliary brake solenoid valve as a second difference.
And the second intake air flow determination module is used for determining the total intake air flow of the cylinder of the engine in the second free fall time as the second intake air flow.
And the second preset threshold determining module is used for determining a second preset threshold according to the second difference and the second air inflow.
And the second fault diagnosis submodule is used for determining whether the auxiliary braking system has non-electrical faults or not according to the second free fall time and a second preset threshold value.
In a possible implementation manner, the second fault diagnosis sub-module may be specifically configured to determine that the auxiliary braking system has a non-electrical fault if the second free fall time is greater than or equal to a second preset threshold, and determine that the auxiliary braking system does not have the non-electrical fault if the second free fall time is less than the second preset threshold.
The embodiment of the application further provides auxiliary brake system fault diagnosis equipment. Alternatively, fig. 5 shows a block diagram of a hardware structure of an auxiliary brake system fault diagnosis device, and referring to fig. 5, the hardware structure of the auxiliary brake system fault diagnosis device may include: at least one processor 501, at least one communication interface 502, at least one memory 503, and at least one communication bus 504;
in the embodiment of the present application, the number of the processor 501, the communication interface 502, the memory 503 and the communication bus 504 is at least one, and the processor 501, the communication interface 502 and the memory 503 complete the communication with each other through the communication bus 504;
the processor 501 may be a central processing unit CPU, or an Application Specific Integrated Circuit ASIC (Application Specific Integrated Circuit), or one or more Integrated circuits configured to implement embodiments of the present invention, etc.;
the memory 503 may include a high-speed RAM memory, and may further include a non-volatile memory (non-volatile memory) or the like, such as at least one disk memory;
wherein the memory 503 stores a program and the processor 501 may call the program stored in the memory 503 for:
determining whether the auxiliary braking system has an electrical fault or not according to the relevant fault parameters of the auxiliary braking system;
if the auxiliary braking system has no electric appliance faults, determining whether the auxiliary braking system is in a service test mode;
if the auxiliary braking system is in the service test mode, the rotation speed of the engine is enabled to fall back freely under the first braking action by adjusting the idle speed set value of the engine and opening the auxiliary braking electromagnetic valve and the throttle valve, and whether the auxiliary braking system has non-electrical equipment faults or not is determined according to the first free fall time of the rotation speed of the engine under the first braking action;
and if the auxiliary brake system is not in the service test mode, detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake solenoid valve are both set, and if so, determining whether the auxiliary brake system has non-electrical faults or not according to the second free fall time of the rotating speed of the engine under the second brake action.
Alternatively, the detailed function and the extended function of the program may refer to the above description.
The embodiment of the application also provides another readable storage medium, on which a computer program is stored, and the computer program is executed by a processor to implement the method for diagnosing the fault of the auxiliary braking system.
Alternatively, the detailed function and the extended function of the program may be as described above.
Finally, it is further noted that, herein, relational terms such as, for example, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A method of fault diagnosis for an auxiliary brake system, comprising:
determining whether the auxiliary braking system has electrical faults or not according to the relevant fault parameters of the auxiliary braking system;
if the auxiliary braking system does not have the electrical appliance fault, determining whether the auxiliary braking system is in a service test mode;
if the service test mode is adopted, increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed, opening an auxiliary braking electromagnetic valve and a throttle valve to enable the rotating speed of the engine to freely fall back under the first braking action, and determining whether the auxiliary braking system has non-electrical equipment faults or not according to the first free fall-back time of the rotating speed of the engine under the first braking action;
and if the auxiliary brake system is not in the service test mode, detecting whether an auxiliary brake solenoid valve driving state parameter and a neutral state parameter are both set, and if so, determining whether the auxiliary brake system has the non-electrical equipment fault according to second free fall time of the rotating speed of the engine under the second brake action.
2. The auxiliary brake system fault diagnosis method according to claim 1, wherein the determining whether the auxiliary brake system has an electrical fault according to the auxiliary brake system related fault parameter comprises:
if the relevant fault parameters of the auxiliary braking system are not set, determining that the auxiliary braking system has no electrical faults;
and if the related fault parameters of the auxiliary braking system are set, determining that the auxiliary braking system has electrical faults.
3. The auxiliary brake system fault diagnosis method according to claim 1, wherein the freely dropping the rotation speed of the engine under the first braking action by increasing the idle speed set value of the engine from the normal idle speed value to the target rotation speed and opening an auxiliary brake solenoid valve and a throttle valve comprises:
starting the engine, and increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed;
and recovering the idle speed set value of the engine to the normal idle speed value, and opening the auxiliary brake electromagnetic valve and the throttle valve to enable the rotating speed of the engine to freely fall back under the first brake action.
4. The auxiliary brake system fault diagnosis method according to claim 3, wherein the first free fall time is a time during which the rotation speed of the engine is reduced from the target rotation speed to a preset rotation speed, the preset rotation speed being greater than or equal to the normal idle speed value;
the determining whether the auxiliary braking system has a non-electrical fault according to the first free fall time of the rotating speed of the engine under the action of the first brake comprises the following steps:
determining a difference value between the target rotating speed and the preset rotating speed as a first difference value;
determining a total intake air flow rate of cylinders of the engine during the first free fall time as a first intake air flow rate;
determining a first preset threshold value according to the first difference value and the first intake air flow rate;
and determining whether the auxiliary braking system has the non-electrical fault according to the first free fall time and the first preset threshold.
5. The auxiliary brake system fault diagnosis method according to claim 4, wherein the determining whether the non-electrical fault exists in the auxiliary brake system according to the first free fall time and the first preset threshold value comprises:
if the first free fall time is larger than or equal to the first preset threshold, determining that the non-electrical fault exists in the auxiliary braking system;
and if the first free fall time is smaller than the first preset threshold value, determining that the auxiliary braking system does not have the non-electrical fault.
6. The auxiliary brake system fault diagnosis method according to claim 3, characterized by further comprising, before the starting the engine and raising an idle speed set value of the engine from a normal idle speed value to a target rotation speed:
and detecting the speed of the whole vehicle, starting the engine when detecting that the speed of the whole vehicle is 0, and increasing the idle speed set value of the engine from the normal idle speed value to the target rotating speed.
7. The auxiliary brake system fault diagnosis method according to claim 1, wherein after detecting that the auxiliary brake solenoid valve driving state parameter and the neutral state parameter are both set, before determining whether the non-electrical fault exists in the auxiliary brake system at the second free fall time under the second braking action according to the rotation speed of the engine, the method further comprises:
detecting whether the driving state parameter of the auxiliary brake solenoid valve is reset or not;
and if the auxiliary brake solenoid valve driving state parameter is reset, taking the time from the setting to the resetting of the auxiliary brake solenoid valve driving state parameter as the second free fall time.
8. The auxiliary brake system fault diagnosis method according to claim 7, wherein the determining whether the non-electrical fault exists in the auxiliary brake system according to a second free fall time of the rotation speed of the engine under a second brake application includes:
determining an engine speed difference value corresponding to the resetting of the auxiliary brake electromagnetic valve driving state parameter from the set value as a second difference value;
determining a total intake air flow rate of cylinders of the engine during the second free fall time as a second intake air flow rate;
determining a second preset threshold according to the second difference and the second intake air flow;
and determining whether the non-electrical faults exist in the auxiliary braking system according to the second free fall time and the second preset threshold.
9. The auxiliary brake system fault diagnosis method according to claim 8, wherein the determining whether the auxiliary brake system has a non-electrical fault according to the second free fall time and the second preset threshold value comprises:
if the second free fall time is greater than or equal to the second preset threshold, determining that the non-electrical fault exists in the auxiliary braking system;
and if the second free fall time is smaller than the second preset threshold, determining that the auxiliary braking system does not have the non-electrical fault.
10. An auxiliary brake system fault diagnosis apparatus, characterized by comprising: the system comprises an electric appliance fault judgment module, a service test mode judgment module, a first fault diagnosis module and a second fault diagnosis module;
the electric appliance fault judging module is used for determining whether the auxiliary braking system has electric appliance faults or not according to the relevant fault parameters of the auxiliary braking system;
the service test mode judging module is used for determining whether the auxiliary braking system is in a service test mode or not if the auxiliary braking system does not have the electrical appliance fault;
the first fault diagnosis module is used for increasing an idle speed set value of an engine from a normal idle speed value to a target rotating speed and opening an auxiliary braking electromagnetic valve and a throttle valve to enable the rotating speed of the engine to freely fall back under a first braking action if the service test mode judgment module determines that the service test mode is in, and determining whether the auxiliary braking system has non-electrical faults or not according to first free fall-back time of the rotating speed of the engine under the first braking action;
and the second fault diagnosis module is used for detecting whether the driving state parameter and the neutral state parameter of the auxiliary brake solenoid valve are both set or not if the service test mode judgment module determines that the auxiliary brake solenoid valve is not in the service test mode, and determining whether the auxiliary brake system has non-electrical equipment faults or not according to the second free fall time of the rotating speed of the engine under the second brake action if the driving state parameter and the neutral state parameter are both set or not.
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| JPH10169471A (en) * | 1996-12-13 | 1998-06-23 | Denso Corp | Brake failure diagnosing device and storage medium |
| JP4225323B2 (en) * | 2006-02-13 | 2009-02-18 | トヨタ自動車株式会社 | Shift control device for continuously variable transmission for vehicle |
| CN202118353U (en) * | 2010-11-01 | 2012-01-18 | 浙江博力机电制造有限公司 | Highly integrated electromagnetic valve body structure for auxiliary automobile brake |
| CN107035542B (en) * | 2017-06-05 | 2020-07-24 | 安徽江淮汽车集团股份有限公司 | Exhaust auxiliary braking device and control method thereof |
| CN110131041B (en) * | 2019-07-10 | 2019-10-18 | 潍柴动力股份有限公司 | A kind of fault detection method and fault detection system of exhaust brake control function |
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