JP2004324599A - Troubleshooting control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect abnormality of idling rotational speed control, from which the failure of a specific system and a specific part cannot be specified, and improve efficiency for analyzing trouble by a troubleshooting control device for a vehicle. <P>SOLUTION: This troubleshooting control device for a vehicle includes a failure detection means, a code setting means, a failure code output means and a failure code preservation means. The device is provided with an idling rotational speed control means controlling the engine speed during idling operation of an engine mounted on the vehicle so that the engine speed is equal to a target speed, a fluctuation detection means detecting the fluctuation of the engine speed within a sampling time which is set during the idling rotational speed control by this idling rotational speed control means, and a failure determination means comparing a value detected by this fluctuation detection means with a set failure determining value and determining the failure of the idling rotational speed control. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a failure diagnosis control device for a vehicle, and in particular, can detect an abnormality of idle speed control such that a failure of a specific system or component cannot be identified, and improves the efficiency of failure analysis by the failure diagnosis control device for a vehicle. TECHNICAL FIELD The present invention relates to a vehicle failure diagnosis control device capable of realizing a vehicle.
[0002]
[Prior art]
In recent years, domestic and foreign exhaust gas regulations have become stricter year by year, and accordingly, the demand for on-board diagnostics (OBD: On-Board Diagnostic) of on-vehicle electronic controllers has also become stricter.
[0003]
In the basic control of the vehicle failure diagnosis control device, when the running state of the vehicle satisfies certain conditions, the input / output of the vehicle-mounted electronic controller is monitored to determine whether the vehicle is normal or abnormal. If it is determined that an abnormality has occurred, a failure code (DTC: Diagnostic Trouble Code) for identifying which component or system is abnormal and the running state when the failure determination is performed are stored in a data holding memory (EEPROM or battery power supply). In the RAM backed up in step (1).
[0004]
As a conventional vehicle failure diagnosis control device, in an engine in which the engine speed during idle operation is controlled by the opening control of an idle speed control actuator, feedback control is performed to a target speed with water temperature as a parameter, and the feedback amount is calculated. Is learned from a difference between the current feedback amount and the feedback amount learned in the past, a failure diagnosis of the idle speed control device is performed (for example, Patent Document 1). reference.).
[0005]
A conventional vehicle failure diagnosis control apparatus calculates a deviation value between an actual engine rotation speed and a target idle rotation speed when controlling the engine rotation speed to a target rotation idle rotation speed determined by an operation state, and calculates the deviation value. If the deviation value after the elapse of the predetermined time set based on the abnormally exceeds the predetermined deviation value set in advance corresponding to the idle speed control, it is determined that there is an abnormality and the air-fuel ratio control actuator is activated. There is one on the lean side that is forcibly driven (for example, see Patent Document 2).
[0006]
As a conventional vehicle failure diagnosis control device, in an idle speed control method for controlling the speed of an internal combustion engine to a target speed set in accordance with an operating state, when the target speed changes, When the rotation speed of the internal combustion engine does not fall within a predetermined range around the target rotation speed, there is a case where idle speed control is determined to be abnormal (for example, see Patent Document 3).
[0007]
[Patent Document 1]
JP-A-62-251449 (page 3, FIG. 4)
[Patent Document 2]
JP-A-60-119337 (pages 3 and 4, FIG. 6)
[Patent Document 1]
JP-A-60-104738 (page 4, FIG. 4)
[0008]
[Problems to be solved by the invention]
By the way, in the conventional vehicle failure diagnosis control device, a failure of a specific system and a part is detected, and a failure code for identifying the content of the failure and a traveling state at the time of failure are stored. Thereafter, when there is a data request from an external failure diagnosis tester, the in-vehicle failure diagnosis control device responds the data to the failure diagnosis tester. The failure diagnostic tester displays the data on a display and notifies the operator of the failure.
[0009]
However, failures detected inside the on-vehicle electronic controller by the conventional vehicle failure diagnosis control device are limited to failures of specific systems and components. On the other hand, a failure of the vehicle brought by the driver for repair cannot be diagnosed by the current in-vehicle failure diagnosis control device, and a failure code often remains.
[0010]
Therefore, in the current vehicle failure diagnosis control device, although failure of a very large number of systems and components can be considered as a factor, when it is impossible to specify a system or a component, it can be determined as a failure. There is a problem that cannot be done. Such failures that cannot be determined as failures include engine start failure, engine stall, idle speed failure, and the like.
[0011]
These engine start failures, engine stalls, idle speed failures, etc. are serious failures for the driver, but cannot be diagnosed as failures by the conventional on-board failure diagnosis control device. Even if a repairman is requested, a trouble code does not remain, so it takes time for the repairman to re-verify the trouble for grasping the situation, and it is difficult to analyze the cause of the trouble.
[0012]
Therefore, the conventional vehicle failure diagnosis control device cannot diagnose failures such as engine start failure, engine stall, idle speed failure, and the like that cannot identify failure of a specific system or component. There is a disadvantage that the efficiency of the method is reduced.
[0013]
[Means for Solving the Problems]
In order to eliminate the above-mentioned inconvenience, the present invention provides a failure detecting means for detecting a failure of a vehicle-mounted component, and a code for setting a different failure code for each vehicle-mounted component so that the failed vehicle-mounted component can be identified. A failure diagnosis control device for a vehicle, comprising: a setting unit, a failure code output unit that outputs a failure code when there is a failed in-vehicle component, and a failure code storage unit that stores a corresponding failure code. Idle speed control means for controlling the engine speed during idle operation of the engine to a target speed, and the engine speed within a set sampling time during idle speed control by the idle speed control means. A fluctuation detecting means for detecting a fluctuation of the number, and a value detected by the fluctuation detecting means and a set failure judgment. Characterized in that it comprises a failure determining means for determining a failure of the idle speed control by comparing and.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The vehicle failure diagnosis control device according to the present invention is set during idle speed control by idle speed control means for controlling the engine speed during idle operation of the engine mounted on the vehicle to be the target speed. The fluctuation of the engine speed within the sampling time detected by the fluctuation detecting means is detected by the fluctuation detecting means, and the value detected by the fluctuation detecting means is compared with a set failure judgment value. Is determined, the fluctuation of the engine speed can be monitored during the idle speed control, and an abnormality of the idle speed control that cannot identify a failure of a specific system or component can be detected.
[0015]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention. In FIG. 3, reference numeral 2 denotes a vehicle, and reference numeral 4 denotes a vehicle-mounted electronic controller in which a failure diagnosis program of a vehicle failure diagnosis control device mounted on the vehicle 2 is programmed. Examples of the on-vehicle electronic controller 4 include an engine controller 4-1 for controlling an engine and an automatic transmission controller 4-2 for controlling an automatic transmission.
[0016]
The engine controller 4-1 and the automatic transmission controller 4-2, which are the in-vehicle electronic controllers 4, are provided so as to be connected to the in-vehicle communication line 6 formed of a serial communication line or a CAN (CONTROLLER AREA NETWORK) communication line.
[0017]
The vehicle-side connector 8-1 of the connector device 8 is connected to the in-vehicle communication line 6. An external device-side connector 8-2 of the connector device 8 is provided on the vehicle-side connector 8-1 so as to be connectable and detachable. The external device side connector 8-2 is provided by connecting a failure diagnosis tester 12 which is an external device provided outside the vehicle 2 by an external communication line 10 composed of a serial communication line or a CAN (CONTROLLER AREA NETWORK) communication line. I have.
[0018]
As shown in FIG. 4, the engine controller 4-1 is provided with a first communication port 14 which is a serial communication port for performing data communication with the failure diagnosis tester 12 by serial communication via the in-vehicle communication line 6, A CPU 16, which is a central processing unit for calculating an optimal control amount for target control based on a signal from an input processing circuit 24 described later and outputting a control signal based on the calculation result, is provided. A block rewritable ROM (flash memory or EEPROM when programmed at a factory) 18 is provided, a RAM 20 is provided for storing data for the CPU 16 to perform calculations, and a control sensor (for example, an engine speed sensor) is provided. , An engine coolant temperature sensor, a battery voltage sensor, etc.) An input processing circuit 24 is provided, and an output control circuit 28 for receiving a control signal from the CPU 16 and driving a control actuator (for example, an idle speed control valve) 26 is provided. An automatic transmission controller 4-2 as another controller is provided. A second communication port 30 for communicating with the vehicle via the in-vehicle communication line 6, and a power supply circuit 36 for connecting a power supply 32 mounted on the vehicle 2 and an ignition switch 34. . The power supply 32 of the vehicle 2 is connected from the connector device 8 to the failure diagnosis tester 12 via the external device-side power line 42 and the external device-side ground line 44 by a vehicle-side power line 38 and a vehicle-side ground line 40. .
[0019]
The engine controller 4-1 causes the CPU 16 to execute a failure diagnosis program by using a failure detection unit 46 that detects a failure of a vehicle-mounted component of the vehicle 2 and a failure detection unit 46 that differs for each vehicle-mounted component so that the failed vehicle-mounted component can be identified. The system includes a code setting unit 48 for setting a failure code, a failure code output unit 50 for outputting a failure code when there is a failed vehicle-mounted component, and a failure code storage unit 52 for storing a corresponding failure code.
[0020]
When the execution condition of the failure diagnosis program is satisfied, the engine controller 4-1 monitors the input / output, detects the failure of the vehicle-mounted component by the failure detection means 46, and determines that the failure has occurred, the code setting means 48 A failure code DTC (DIAGNOstic TROUBLE CODE) set according to the vehicle-mounted parts and a running state when the failure is determined are stored in a data storage memory such as an internal EEPROM or a RAM backed up by a battery power supply (FIG. (Not shown).
[0021]
When the failure diagnosis tester 12 is connected to the engine controller 4-1 via the connector device 8, the failure diagnosis tester 12 is activated by being supplied with power from the power supply 32, and starts operating when the failure diagnosis tester 12 is stored in the data storage memory inside the engine controller 4-1. The code DTC and the running state are read and displayed on a display (not shown).
[0022]
The engine controller 4-1 constituting the vehicle failure diagnosis control device includes an idle speed control unit 54. The idling speed control means 54 detects the idling speed of the engine mounted on the vehicle 2 during idling by the sensor 20, and increases / decreases, for example, the intake air amount of the engine by the actuator 26. Control is performed so as to reach the set target rotation speed.
[0023]
The engine controller 4-1 includes a fluctuation detecting means 56 for detecting a fluctuation of the engine rotational speed within a set sampling time during the idle rotational speed control by the idle rotational speed control means 54. A failure determination unit 58 is provided for comparing the set value with a set failure determination value to determine a failure in idle speed control. The fluctuation detecting means 56 detects a value obtained by integrating the difference between the maximum value and the minimum value of the fluctuation of the engine speed within the sampling time.
[0024]
Next, the operation will be described with reference to the control flowchart of FIG.
[0025]
When the control is started (100), the engine controller 4-1 in which the failure diagnosis program of the vehicle failure diagnosis control device is programmed clears the rotation speed deviation integrated value of the engine rotation speed (102), and performs the idle rotation speed control. It is determined (104) whether a predetermined time has elapsed from the start of the rotation speed feedback control.
[0026]
If the determination (104) is NO, the process returns to the process (102) and the determination (104) is repeated. If the determination (104) is YES, the timer of the rotation speed fluctuation detection cycle T6 of the engine rotation speed is started (106), and it is determined whether the ignition switch 34 is turned off (108).
[0027]
If the judgment (108) is YES, the process is ended (110). If this determination (108) is NO, it is determined (112) whether or not the rotation speed feedback control of the idle rotation speed control is being continued.
[0028]
If this determination (112) is NO, the process returns to the process (102). If the determination (112) is YES, the timer of the engine speed rotational speed deviation detection cycle T5 is started (114), the maximum value NeA of the engine speed fluctuation is obtained (116), and the rotational speed deviation detection is performed. It is determined whether the period T5 has elapsed (118).
[0029]
If this determination (118) is NO, this determination (118) is repeated. If the determination (118) is YES, the minimum value NeB of the change in the engine speed is obtained (120), the integrated value of the engine speed deviation is updated (122), and whether or not the engine speed change detection period T6 has elapsed. It is determined (124). The rotational speed deviation integrated value is updated by the equation: rotational speed deviation integrated value = previous rotational speed deviation integrated value + | NeA-NeB |.
[0030]
If the determination (124) is NO, the process returns to the determination (108). If this determination (124) is YES, it is determined (126) whether or not the rotational speed deviation integrated value exceeds the abnormality determination rotational speed which is a failure determination value.
[0031]
If the determination (126) is YES, the abnormal code, which is the failure code, is stored in the data storage memory (128) and stored, and the number of idle malfunctions (rotational speed hunting) is incremented (INCREMENT) (130). The rotational speed deviation integrated value is cleared (132), and the process returns to the process (106). If this determination (126) is NO, the rotational speed deviation integrated value is cleared (132) and the process returns to (106).
[0032]
In this manner, as shown in FIG. 2, during detection of a failure within the predetermined period T6 of the idle speed control, the engine controller 4-1 outputs the maximum value of the fluctuation of the engine speed as various control data in the predetermined period T5. NeA and the minimum value NeB are sampled, the maximum value NeA and the minimum value NeB of the sampled data are compared, and the integrated value of the difference between the maximum value NeA and the minimum value NeB is updated.
[0033]
If the abnormality converges during the sampling time T5 (startup completed, idle speed converges near the target speed, etc.), the integrated value of the difference between the maximum value NeA and the minimum value NeB is cleared, and the abnormality is determined. Only the abnormal code is stored in the data storage memory together with various control states at the time of determination.
[0034]
In addition, the sampling time for each abnormality detection is a time from the start of the idle failure detection to the convergence of the idle failure when the idle speed is poor, and a time from the starter ON to the starter OFF when the start is poor.
[0035]
As a result, the engine controller 4-1 in which the failure diagnosis program of the vehicle failure diagnosis control device is programmed can monitor the fluctuation of the engine rotation speed during the idle rotation speed control, and the failure of a specific system or component can be monitored. Can be detected when idle speed control cannot be specified.
[0036]
Therefore, the engine controller 4-1 constituting the vehicle failure diagnosis control device can realize more efficient failure analysis by the vehicle failure diagnosis control device. Further, as a means for improving the efficiency of the failure analysis, a control sensor (for example, an engine speed sensor, an engine coolant temperature sensor, a battery voltage sensor, etc.) 22 or a control sensor 22 connected to the engine controller 4-1 during abnormality detection. Detecting the maximum value and the minimum value of an actuator (for example, an idle speed control valve or the like) 26 and storing these values as data in a data storage memory. This makes it possible to estimate the transition of the values of the control sensor 22 and the actuator 26 and the control constants input and output to and from the engine controller 4-1 in the event of an abnormality. Can be shortened.
[0037]
The present invention is not limited to the above-described embodiment, and various modifications can be made.
[0038]
For example, in the embodiment of the present invention, the determination is made by comparing the integrated value of the difference between the maximum value NeA and the minimum value NeB of the fluctuation of the engine speed detected within the sampling time T5 with the set abnormality determination value. Is determined by comparing the number of times the engine speed changes between the maximum value NeA and the minimum value NeB detected within the sampling time T5 with the set abnormality determination value, thereby determining the abnormality of the idle speed control. Can be detected.
[0039]
Further, in the embodiment of the present invention, when the integrated value of the difference between the maximum value NeA and the minimum value NeB of the fluctuation of the engine speed detected within the sampling time T5 exceeds the set abnormality determination value, a failure is determined. If it is determined that the integrated value tends to approach the abnormality determination value, the number of times of detection of the maximum value NeA and the minimum value NeB of the engine speed within the sampling time T5 is increased, or the interval of the sampling time T5 is increased. , The accuracy of the abnormality determination can be increased.
[0040]
【The invention's effect】
As described above, the vehicle failure diagnosis control device of the present invention can monitor fluctuations in the engine speed during idle speed control, and perform idle speed control such that failure of a specific system or component cannot be specified. An abnormality can be detected.
Therefore, the vehicle failure diagnosis control device of the present invention can realize more efficient failure analysis by the vehicle failure diagnosis control device.
[Brief description of the drawings]
FIG. 1 is a control flowchart of a vehicle failure diagnosis control device according to an embodiment of the present invention.
FIG. 2 is a timing chart at the time of sampling a maximum value and a minimum value of engine speed fluctuation.
FIG. 3 is a schematic side view of a vehicle equipped with the vehicle failure diagnosis control device.
FIG. 4 is a block diagram showing a communication system of the vehicle failure diagnosis control device.
[Explanation of symbols]
2 Vehicle 4 In-vehicle electronic controller 4-1 Engine controller 4-2 Automatic transmission controller 6 In-vehicle communication line 8 Connector device 10 Out-of-vehicle communication line 12 Failure diagnosis tester 16 CPU
18 ROM
20 RAM
32 power supply 34 ignition switch 36 power supply circuit 46 failure detection means 48 code setting means 50 failure code output means 52 failure code storage means 54 idle speed control means 56 fluctuation detection means 58 failure determination means

Claims (2)

Failure detection means for detecting a failure of a vehicle-mounted component; code setting means for setting a different failure code for each vehicle-mounted component so that the failed vehicle-mounted component can be identified; A fault diagnosis control device for a vehicle, comprising: a fault code output unit that outputs a fault code; and a fault code storage unit that stores a corresponding fault code. And a fluctuation detecting means for detecting a fluctuation of the engine speed within a set sampling time during the idle speed control by the idle speed control means. A failure of idle speed control is determined by comparing a value detected by the detection means with a set failure determination value. The vehicle failure diagnosis control apparatus characterized by comprising disabilities determination means. 2. The fault diagnosis control device for a vehicle according to claim 1, wherein the fluctuation detecting means detects a value obtained by integrating a difference between a maximum value and a minimum value of the fluctuation of the engine speed within a sampling time.

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