JP2012206629A - Electronic control system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determination a state preceding a failure.SOLUTION: While detecting the failure caused to an objective device of a failure diagnosis, an operation state parameter of a vehicle related to the objective device is obtained and it is determined whether or not the behavior of the obtained operation state parameter has a tendency to lead to the failure of the objective device. When the failure is detected (time t6), predetermined failure-time control corresponding to the detected failure is carried out. When it is determined that there is the tendency to lead to the failure (time t4), pre-failure control which is different from the failure-time control is carried out.

Description

  The present invention relates to a vehicular electronic control device that detects a failure occurring in an in-vehicle device used for vehicle control.

  In vehicle control, when detecting a failure that occurs in an in-vehicle device, instead of making a failure determination immediately after detecting an event indicating the occurrence of the failure, a predetermined determination condition is satisfied (in many cases, A deterministic decision is made after waiting for the event to be detected multiple times in succession (Patent Document 1 below).

JP 2001-050382 A

  However, in the failure detection by such a method, control (for example, notification to the driver) for dealing with the failure is performed only after a definitive determination is made by the establishment of the determination condition. Therefore, in an in-vehicle device that has not completely failed, but is in a state before the failure, the detection of the event is temporary or accidental even though the deterioration or damage has progressed considerably. Since the determination condition is not satisfied, a definitive determination is not made and no special measures are taken for the purpose of protection or the like.

  Therefore, an object of the present invention is to make it possible to cope with not only a failure but also a pre-failure state for an in-vehicle device subject to failure diagnosis.

  The present invention acquires a failure detection means for detecting a failure that occurs in a failure diagnosis target device mounted on a vehicle, the driving state parameter of the vehicle related to the target device, and the behavior of the acquired driving state parameter A failure tendency determining means for determining whether or not there is a tendency to reach the failure of the target device; and for executing predetermined control at the time of failure according to the detected failure when the failure detecting means detects the failure And a second control unit for executing pre-failure control different from the failure-time control when the failure tendency control means outputs the first signal and the failure tendency determination means determines that the failure tends to occur. And a vehicle pre-failure control means for outputting the above signal.

  According to the present invention, a failure occurring in the failure diagnosis target device is detected, and predetermined failure time control corresponding to the detected failure is executed, while the behavior of the vehicle driving state parameter with respect to the failure diagnosis target device is monitored, When there is a tendency to cause a failure of the failure diagnosis target device in the behavior, this can be determined by the failure tendency determining means, and the pre-failure control can be executed. In this way, not only the failure is dealt with, but also the presence of the tendency in the behavior of the operation state parameter is determined, so that the state before the failure can be determined for the device, and the state before the failure is established via the second signal. Can be dealt with.

The block diagram of the engine which mounted the electronic control apparatus (engine control unit) for vehicles which concerns on one Embodiment of this invention. The flowchart which shows the basic flow of the failure detection control which an engine control unit same as the above performs Flowchart showing details of state determination process before failure in failure detection control Explanatory drawing which shows operation | movement of the engine control unit regarding failure detection control (and state determination processing before failure) same as above. Explanatory drawing which shows operation | movement of the engine control unit regarding the failure detection control which concerns on other embodiment of this invention. The flowchart which shows the content of the state determination process before failure which concerns on another embodiment of this invention. Explanatory drawing which shows operation | movement of the engine control unit regarding the failure detection control which concerns on embodiment same as the above.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a configuration of an internal combustion engine (hereinafter referred to as “engine”) 1 on which an electronic control device for a vehicle according to an embodiment of the present invention is mounted, with an automatic transmission 2 connected to its output shaft added. ing.

  The engine 1 includes an electric throttle device 12 in an intake pipe 11, and the electric throttle device 12 includes a butterfly throttle valve that is driven to open and close by an electric motor (not shown). The output torque of the engine 1 is controlled by adjusting the opening of the throttle valve by an engine control unit (hereinafter referred to as “ECU”) 13.

  The automatic transmission 2 includes a gear-type mechanical transmission 21 disposed on the output side of the engine 1 and a torque converter 23 interposed between the engine 1 and the mechanical transmission 21. The pump impeller of the torque converter 23 is connected to the output shaft of the engine 1, while the turbine runner of the torque converter 23 is connected to the input shaft of the mechanical transmission 21. The gear stage of the mechanical transmission 21 is controlled by a hydraulic control mechanism 22, and the hydraulic pressure supplied to each transmission element such as a transmission clutch is controlled according to a transmission control signal from an automatic transmission control unit (ATC / U) 24. Thus, for example, the gear position is switched between the first speed to the fourth speed.

  In the present embodiment, the ECU 13 and the automatic transmission control unit 24 are configured to be able to communicate with each other via the communication line 31. Furthermore, in this embodiment, the engine rotation which outputs the output signal of the accelerator sensor 51 which detects the depression amount of the accelerator pedal by a driver | operator, and the signal synchronized with the crankshaft rotation of the engine 1 with respect to ECU13 as a driving | running state parameter of a vehicle. While the output signal of the sensor 52 and the output signal of the air flow meter 53 for detecting the intake air flow rate of the engine 1 are input, the rotational speed of the turbine runner of the torque converter 23 (hereinafter referred to as “turbine”) is transmitted to the automatic transmission control unit 24. The output signal of the turbine rotation sensor 54 for detecting the “rotation speed” and the output signal of the vehicle speed sensor 55 for detecting the rotation speed of the output shaft of the automatic transmission 2 (correlation with the traveling speed of the vehicle) are input. Sensor information acquired by the ECU 13 and the automatic transmission control unit 24 can be communicated with each other, and can be shared between the control units 13 and 24.

  The automatic transmission control unit 24 sets the target shift speed according to the vehicle speed and the amount of depression of the accelerator pedal in the automatic shift mode, and sets the target shift speed according to the position of the shift lever in the manual shift mode. If it is different from the target shift speed, a shift request is generated and a shift control signal for setting the shift speed as the target shift speed is output to the hydraulic control mechanism 22.

  In the present embodiment, the ECU 13 has a function as a “vehicle electronic control device”, detects a failure occurring in the engine rotation sensor 52, and determines whether the engine rotation sensor 52 is in a pre-failure state. . In general failure detection of the engine rotation sensor 52, after detecting a fluctuation indicating the occurrence of a disconnection that can be listed as one of detection targets in the sensor output signal, the signal level after the fluctuation continues for a predetermined time. Thus, a definitive determination is made that a failure has occurred in the engine rotation sensor 52. However, in the failure detection by this method, the wiring of the engine rotation sensor 52 is not in a state of being disconnected, but a definitive judgment is made only after the disconnection is reached. Although the sensor output signal can be replaced by the output from another sensor having the above, the driver cannot be prepared in advance for the failure of the sensor 52 itself. In the present embodiment, the engine rotation sensor 52 is a “failure diagnosis target device”, and a disconnection that has occurred in the engine rotation sensor 52 as a failure to be detected is regarded as a pre-failure state to be determined. Assume a hanging state. As a result, although the complete disconnection has not been reached, it is possible to cope with the case where the wiring is broken. The “vehicle electronic control device” can be implemented not only by the ECU 13 but also by other in-vehicle devices (for example, the automatic transmission control unit 24) according to the failure mode to be detected.

  FIG. 2 is a flowchart showing a basic flow of failure detection control executed by the ECU 13.

In S101, a sensor output signal is read. In this embodiment, the output signal of the engine rotation sensor 52 is read.
In S102, it is determined whether a predetermined failure condition is satisfied based on the read sensor output signal. In the present embodiment, it is determined whether or not the sensor output signal is equal to or lower than a predetermined signal level indicating occurrence of disconnection in the engine rotation sensor 52. If the failure condition is satisfied, the process proceeds to S103, and otherwise, the process proceeds to S104. In the pre-failure state in which the wiring is about to be disconnected, both a state (normal state) and a state (failure state) in which the sensor output signal is higher than the predetermined signal level can be taken due to vehicle running vibration or the like.

In S103, the failure detection number counter CNT1 is incremented by a predetermined value (for example, 1).
In S104, the failure detection number counter CNT1 is cleared (CNT = 0). As described above, the failure detection number counter CNT1 is cleared every time the failure condition is not satisfied.

  In S105, it is determined whether or not the engine rotation sensor 52 is in a pre-failure state. The contents of the pre-failure state determination process will be described later with reference to the flowchart shown in FIG. The pre-failure state determination process is a process of setting the pre-failure state determination flag FLG2 according to the determination result. In the present embodiment, the pre-failure state determination flag FLG2 is normally set to 0, and the engine rotation sensor 52 is set. Is switched to 1 when it is determined that is in the pre-failure state. In the present embodiment, the function as “failure tendency determination means” is realized by the processing of S105 and S108 described later.

  In S106, it is determined whether or not the failure detection number counter CNT1 after counting up has reached a predetermined value. If the predetermined value has been reached, the process proceeds to S107, and otherwise, the process proceeds to S108. In the present embodiment, the function as “failure detection means” is realized by the processing of S102, 103, and 106.

In S107, a failure detection flag FLG1 is set (for example, FLG1 = 1).
In S108, it is determined whether or not the engine rotation sensor 52 is in a pre-failure state. The determination as to whether or not the vehicle is in the pre-failure state is performed in the pre-failure state determination process in S105. When the pre-failure state determination flag FLG2 set in the process is 1, the engine rotation sensor 52 is in the pre-failure state. If not, the process proceeds to S109. Otherwise (for example, 0), the process proceeds to S110 because it is not in the pre-failure state.

  In S109, the control (pre-failure control) corresponding to the pre-failure state of the engine rotation sensor 52 is executed. In the present embodiment, as the pre-failure control, the driver is notified that the engine rotation sensor 52 is in the pre-failure state and the wiring is about to be cut. The notification to the driver may be made by turning on a warning light or by emitting a warning sound. As a result, the driver can be urged to inspect and repair the engine rotation sensor 52 before the engine rotation sensor 52 is disconnected. Instead of or in addition to the notification to the driver, the execution period of the failure detection control may be shortened. As a result, when an actual disconnection occurs in the engine rotation sensor 52, this can be dealt with promptly. Is possible. In the present embodiment, the function as “pre-failure control means” is realized by the processing of S109.

  In S110, it is determined whether or not the failure detection flag FLG1 is set. If it is set (FLG1 = 1), the process proceeds to S111. Otherwise, the current control is terminated without performing the next failure control.

  In S111, failure time control is executed. In the present embodiment, control for notifying the driver that the engine rotation sensor 52 has been disconnected is executed. For example, when a warning light is turned on to notify that the vehicle is in the pre-failure state, it can be handled by changing the color of the warning light. In the present embodiment, the function as the “failure control means” is realized by the processing of S111.

  FIG. 3 is a flowchart showing the contents of the pre-failure state determination process (S105 shown in FIG. 2) in the failure detection control.

  In S201, it is determined whether or not a predetermined failure condition is satisfied for the engine rotation sensor 52. This determination may be the same content as the processing in S102. If the failure condition is satisfied, the process proceeds to S202. Otherwise, the process returns to the basic routine of failure detection control (hereinafter simply referred to as “basic routine”) shown in FIG.

  In S202, it is determined whether or not a condition satisfaction number holding flag (hereinafter referred to as “number holding flag”) FLG3 is set. If it is set, the process proceeds to S205. Otherwise, the process proceeds to S203. In the present embodiment, the number holding flag FLG3 is normally set to 0, and is switched to 1 in the next processing of S203.

In S203, the number holding flag FLG3 is set (for example, FLG3 = 1).
In S204, the condition satisfaction count holding timer (hereinafter referred to as “number holding timer”) TIM1 is reset (TIM1 = 0). Thus, the number holding timer TIM1 is reset when the number holding flag FLG3 is switched from 0 to 1 (in the process of S203).

  In S205, it is determined whether or not the time indicated by the count holding timer TIM1 is within a predetermined time Δt. If it is within the predetermined time Δt, the process proceeds to S206, otherwise (in other words, when a predetermined time or more has elapsed since the count holding timer TIM1 was reset in the process of S204), The process proceeds to S209.

In S206, the condition satisfaction number counter CNT2 is counted up by a predetermined value (for example, 1).
In S207, it is determined whether or not the condition satisfaction number counter CNT2 after counting up has reached a predetermined value. If the predetermined value has been reached, the process proceeds to S208. Otherwise, the process returns to the basic routine without performing the process of S208.

In S208, it is determined that the engine rotation sensor 52 is in the pre-failure state, and the pre-failure state determination flag FLG2 is set to 1.
In S209, the count holding flag FLG3 is cleared (FLG3 = 0).

  In S210, the condition satisfaction number counter CNT2 is cleared (CNT2 = 0). As described above, the number holding flag FLG3 and the condition satisfaction number counter CNT2 are set to have a predetermined time indicated by the number holding timer TIM1 after the number holding flag FLG3 is switched from 0 to 1 (S203) due to the establishment of the failure condition (S201). Each time the time Δt elapses, it is cleared. Therefore, in the present embodiment, the condition satisfaction number counter CNT2 indicates the cumulative value of the number of times that the failure condition is satisfied within the predetermined time Δt.

  FIG. 4 is an explanatory diagram showing the operation of the ECU 13 related to the failure detection control (and the pre-failure state determination process) shown in FIG. The operation of the ECU 13 related to the control will be described with reference to FIG.

  As shown in FIG. 4, when the ECU 13 determines that the failure condition is satisfied at time t1, the ECU 13 counts up both the failure detection number counter CNT1 and the condition satisfaction number counter CNT2. In the present embodiment, the failure detection number counter CNT1 is for detecting a failure (disconnection) that has occurred in the engine rotation sensor 52, and is cleared every time the failure condition is not satisfied, while the condition satisfaction number counter CNT2 is detected. Is for determining the state of disconnection before the disconnection, and is cleared each time a predetermined time Δt elapses without making the pre-failure state determination (time t2). In the example shown in FIG. 4, the ECU 13 makes a definitive determination that the engine rotation sensor 52 is disconnected at time t <b> 6 when the failure condition is continuously determined four times, and sets the failure detection flag FLG <b> 1 to 1. Set to. On the other hand, at the time t4 when the cumulative number of failure conditions (condition satisfaction number counter CNT2) within a predetermined time Δt reaches a predetermined value (3 in the present embodiment), the wiring of the engine rotation sensor 52 is cut off. It is determined that the current state is present, and the pre-failure state determination flag FLG2 is set to 1. The operation of the ECU 13 when there is a failure detection and a pre-failure state determination is as described above.

  Thus, according to the present embodiment, when a failure (disconnection) occurring in the engine rotation sensor 52 is detected and this is actually detected, it is possible to notify the driver of the occurrence of the disconnection. Furthermore, according to the present embodiment, by monitoring the behavior of the output signal of the engine rotation sensor 52, it can be determined that the wiring of the engine rotation sensor 52 is in a state of being disconnected (pre-failure state), By notifying the driver when it is determined that the wiring is about to be disconnected, it is possible to urge the engine rotation sensor 52 to be inspected and repaired before the disconnection occurs.

Hereinafter, other embodiments of the present invention will be described.
The determination of whether or not it is in the pre-failure state is performed not only by information obtained from the failure diagnosis target device (in the above example, the engine rotation sensor 52) itself, but also by other correlations with the failure diagnosis target device. It is also possible to carry out based on information obtained from an in-vehicle device. Specifically, based on information obtained from other in-vehicle devices, the expected value of the operation that the fault diagnosis target device should perform is calculated, and the fault diagnosis target device fails based on the difference between the measured value and the expected value. It is determined whether or not it is in the previous state.

  FIG. 5 is an explanatory diagram showing the operation of the ECU 13 regarding the failure detection control (and the state determination process before failure) in such a case. In the present embodiment, the turbine rotation sensor 54 is a “failure diagnosis target device”, and the ECU 13 has a function as a “vehicle electronic control device”. The failure to be detected is a disconnection that occurs in the turbine rotation sensor 54, and the pre-failure state to be determined is a state in which the wiring in the turbine rotation sensor 54 is about to be disconnected. The basic flow of the failure detection control and the content of the pre-failure state determination process may be the same as those shown in FIGS.

As shown in FIG. 5, the rotational speed of the turbine runner (turbine rotational speed Nt) is calculated from the engine rotational speed, vehicle speed, and gradient resistance (road slope), and the calculated turbine rotational speed Nt _cal and actual turbine rotational speed Nt are calculated. (Detected by the turbine rotation sensor 54). Then, when the difference between the two (= Nt _cal −Nt) is equal to or greater than a predetermined value, the failure detection and the pre-failure state determination shown in FIGS. . Here, in the pre-failure state determination process shown in FIG. 3, the cumulative number of failure conditions within a predetermined time Δt is employed. In the present embodiment, the accumulated number of failure conditions may be adopted similarly to this, or instead, the accumulated or accumulated value of the difference (= Nt _cal −Nt) within the predetermined time Δt, or the maximum Values may be used, and when these values have reached predetermined values, it may be determined that the pre-failure state is present. When the pre-failure state of the turbine rotation sensor 54 is determined, as the pre-failure control for this, the estimated turbine rotation speed obtained by estimating the turbine rotation speed Nt from the output signals of other sensors (such as the engine rotation sensor 52 and the vehicle speed sensor 55). Instead of Nt _est, it is reflected in vehicle control (for example, shift control), or a warning lamp is activated to notify the driver that the vehicle is in a pre-failure state.

  FIG. 6 is a flowchart showing the contents of the pre-failure state determination process according to still another embodiment of the present invention. In the present embodiment, the fastening element (for example, a shift clutch) of the automatic transmission 2 is a “failure diagnosis target device”, and the ECU 13 functions as a “vehicle electronic control device”. The failure to be detected is deterioration due to wear of the transmission clutch, and the pre-failure state to be determined is a state in which the deterioration has progressed to the extent that protection control is required, although it does not lead to determination as a failure. . In the conventional failure detection method, which performs control to deal with this only after determining that a failure has occurred, the deterioration gradually progresses like a shift clutch, and finally it should be in a state that should be considered a failure. In such cases, no special measures are taken for the purpose of protection or the like until a definitive judgment is made regarding the failure. In the present embodiment, when the deterioration of the transmission clutch proceeds, this is determined as a pre-failure state, and control for the purpose of protecting the transmission clutch is executed. The failure of the transmission clutch can be detected because the proper engagement hydraulic pressure is not applied to the transmission clutch even though the hydraulic pressure supplied by the hydraulic control mechanism 22 is sufficient (the actual transmission speed does not match the target transmission speed). Is possible. In the present embodiment, the determination as to whether or not the vehicle is in the pre-failure state is performed as follows. FIG. 7 is an explanatory diagram showing the operation of the ECU 13 relating to the failure detection control, and the flowchart shown in FIG. 6 will be described with reference to FIG.

In S301, sensor output signals are acquired in time series order. In the present embodiment, the hydraulic pressure applied to the transmission clutch (hereinafter referred to as “engagement hydraulic pressure”) is detected.
In S302, it is determined whether or not acquisition of sensor output time-series information for one control is completed. In the present embodiment, a series of engagement hydraulic pressures from the start of the shifting operation (time t1 shown in FIG. 7) to the end thereof (time t4) are acquired. When acquisition is completed, it progresses to S303, and acquisition of sensor output time series information is continued in other cases.

  In S303, a state deviation amount is calculated. In the present embodiment, an ideal pattern of fastening hydraulic pressure for one control is obtained in advance through experiments or the like, and this is stored in the storage unit of the ECU 13. In actual control, the sensor output time series information (ECU acquisition data) acquired by the ECU 13 is compared with the ideal pattern of the shift hydraulic pressure, and the accumulated value of the difference between the two within one control period (FIG. 7) To calculate the area of the portion indicated by diagonal lines. In this embodiment, the sensor output time series information for one control is waited for completion and compared with the ideal pattern.However, each time the fastening hydraulic pressure is acquired, it is compared with the ideal pattern value, and the difference between the two is calculated. The state divergence amount may be calculated by sequentially integrating.

In S304, it is determined whether or not the calculated state deviation amount is within a predetermined range. If it is within the predetermined range, the current pre-failure state determination process is terminated, otherwise the process proceeds to S305.
In S305, it is determined that the shift clutch is in the pre-failure state, and the pre-failure state determination flag FLG2 is set (for example, FLG2 = 1).

  In the present embodiment, as the pre-failure control for the pre-failure state determination, in addition to notifying the driver, control for protecting the shift clutch that is the failure diagnosis target device is performed. Specifically, the shift operation involving the shift clutch is limited, or the shift time is changed with respect to the normal setting. As an example of the former, while a shift with an operation from the engaged state to the released state of the shift clutch is allowed, a shift with an operation from the open state to the engaged state is prohibited. When a shift to be restricted is requested, it may be allowed with a condition by waiting for a predetermined time after the request and executing the shift. As an example of the latter, in this embodiment, the progress of wear is suppressed by shortening the shift time. However, this may be extended depending on the type of failure to be detected. For example, when detecting a failure that has occurred in the hydraulic system, it is possible to protect the hydraulic system and extend the period until failure by extending the shift time and preventing the shock associated with the shift operation. it can. In this case, it is preferable to prevent an excessive increase in the oil temperature by extending the oil temperature only when the oil temperature is lower than a predetermined temperature or increasing the operation frequency of the oil cooler (ATF cooler).

  When a clogging of the hydraulic passage is detected as a failure, the pre-failure state can be dealt with by increasing the frequency of cleaning for temporarily removing the clog by increasing the hydraulic pressure temporarily as the pre-failure control.

  In this embodiment, the sensor output time-series information is obtained and the state deviation amount is calculated in units of one control (from the start of the shift to the end of the shift). However, the present invention is not limited to this. For example, sensor output time series information in the torque phase is acquired in units of the torque phase or inertia phase), and it is determined whether or not the shift clutch is in a pre-failure state based on the state deviation amount in the torque phase. May be.

  Needless to say, when the learning hydraulic correction causes a change in the engagement hydraulic pressure over time or a change in the shift time with respect to the initial setting, the ideal pattern may be adjusted accordingly.

  In the present embodiment, it is determined whether or not there is a pre-failure state by comparing the actual engagement hydraulic pressure with the ideal pattern, but an NG pattern (a typical hydraulic pattern at the time of failure) is stored instead of the ideal pattern. In addition, in actual control, the engagement hydraulic pressure may be compared with this NG pattern to determine whether or not there is a pre-failure state based on the degree of coincidence between the two.

  The determination using the sensor output time series information can be applied not only to the shift clutch but also to all failure diagnosis target devices that can predict the fluctuation pattern of the hydraulic pressure or the oil amount. For example, for a cooling oil pump for a transmission clutch (wet clutch), when the amount of oil at the time of refueling is greatly deviated from its ideal pattern, it can be determined that it is in a pre-failure state. . When the pre-failure state determination is made for the cooling oil pump, the driver is urged to recognize it by notification or the like, and the operation of the shift clutch is restricted.

  As a pre-failure control that can be applied in common to all of the specific examples described above, the result of the pre-failure state determination (pre-failure state determination flag FLG2) is stored as backup information so that it can be retained after the power is shut off. The determination result is adopted when driving the vehicle. Thereby, repeated determination can be avoided and the processing load can be reduced.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 11 ... Intake pipe, 12 ... Electric throttle device, 13 ... Engine control unit (ECU), 2 ... Automatic transmission, 21 ... Mechanical transmission, 22 ... Hydraulic control mechanism, 23 ... Torque converter, 24 ... Automatic transmission control unit, 31 ... communication line, 51 ... accelerator sensor, 52 ... engine rotation sensor, 53 ... air flow meter, 54 ... turbine rotation sensor, 55 ... vehicle speed sensor.

Claims (3)

A failure detection means for detecting a failure that occurs in a failure diagnosis target device mounted on a vehicle;
A failure tendency determining means for acquiring a driving state parameter of the vehicle related to the target device, and determining whether the behavior of the acquired driving state parameter has a tendency to lead to the failure of the target device;
When the failure detection means detects the failure, a failure time control means for outputting a first signal for executing a predetermined failure time control according to the detected failure;
A pre-failure control means for outputting a second signal for executing a pre-failure control different from the on-failure control when the failure tendency determination means determines that the failure tends to occur;
An electronic control device for a vehicle comprising the above.   The vehicular electronic control device according to claim 1, wherein the pre-failure control is a control that reduces a burden on the target device in the control of the vehicle. When the target device is to detect the operating state parameter,
2. The vehicle electronics according to claim 1, wherein the pre-failure control is control in which another driving state parameter correlated with the driving state parameter detected by the target device is reflected in the control of the vehicle. Control device.