JP5664926B2 - Start control device for internal combustion engine - Google Patents

Description

  The present invention relates to a start control device for an internal combustion engine that includes start control means for performing start control of the internal combustion engine and receiving information transmitted by CAN communication from other control means.

  In a start control system for an internal combustion engine (engine) mounted on a vehicle, for example, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2008-291863), power management is performed separately from an engine ECU that controls the engine. An ECU is provided, and vehicle information is transmitted and received between the engine ECU and the power management ECU through CAN (Controller Area Network) communication, and engine start control (cranking control) is performed by the power management ECU. Some have made it possible to start the engine even when the engine ECU is reset due to a decrease in battery voltage.

Japanese Patent Laying-Open No. 2008-291863 (FIG. 7 etc.)

  By the way, in a system in which start control is performed by a start ECU (for example, a power management ECU) provided separately from the engine ECU, the start ECU receives an event frame transmitted only during cranking by CAN communication. Has been developed. In a system employing such a communication specification, the applicant resets the event frame reception state flag to “ERROR” when reception of the event frame is interrupted during cranking, as shown in FIG. The diagnostic code storage flag is reset to “ERROR”, and if the diagnostic code storage flag is “ERROR” at the end of the cranking, the abnormality diagnosis for storing the diagnostic code after a predetermined precondition is established is being studied. However, the following new issues were found in the research process.

  In the above-described abnormality diagnosis, the diagnosis code is stored even if it is determined that the reception of the event frame is interrupted only for a short time immediately before the end of cranking even though no abnormality has actually occurred. Will be. In this case, when the vehicle is inspected at a dealer or the like, the diagnosis code is stored despite the fact that no abnormality has actually occurred, so the vehicle will be inspected more than necessary. Doing extra work.

  In addition, in the above-described abnormality diagnosis, if an abnormality occurs during cranking and event frame reception is interrupted, and the event frame reception state returns to normal before the end of cranking, an abnormality is actually detected. However, there is a drawback that the diagnostic code is not stored despite the occurrence of the error.

  Therefore, the problem to be solved by the present invention is to provide a start control device for an internal combustion engine that can improve the accuracy (abnormality diagnosis accuracy) of the diagnostic code storage processing based on the reception state of the event frame.

In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a start control means for performing start control of the internal combustion engine and receiving an event frame transmitted during cranking by CAN communication from another control means. In the internal combustion engine start control device, the start control means integrates the event frame interruption time when reception of the event frame is interrupted during cranking, and the event frame is received even if the event frame is received. The accumulated value of the interruption time of the frame is held without being cleared, and an abnormality diagnosis is performed in which a diagnosis code is stored when the integrated value of the interruption time of the event frame exceeds a predetermined determination threshold value.

  In this way, an event occurred when the event frame was interrupted frequently, or the event frame was continuously interrupted for a long time, and the accumulated value of the event frame exceeded the judgment threshold. Thus, the diagnosis code can be stored, and the accuracy (abnormality diagnosis accuracy) of the diagnosis code storage processing based on the reception state of the event frame can be increased.

  For example, if it is determined only once that the reception of the event frame has been interrupted for a short time immediately before the end of cranking, the integrated value of the event frame interruption time does not exceed the determination threshold value, and thus an abnormality has occurred. The diagnosis code is not memorized. As a result, the diag code is stored unnecessarily when it is determined that the reception of the event frame is interrupted only once for a short time just before the end of the cranking even though no abnormality has actually occurred. Can be prevented.

  Further, when reception of an event frame is temporarily interrupted during cranking, if the integrated value of the event frame interruption time exceeds a determination threshold, it is determined that an abnormality has occurred and a diagnosis code is stored. As a result, even after an event occurs during cranking and the reception of the event frame is interrupted, the diag code can be stored even when the event frame reception state returns to normal before the cranking ends.

  In this case, as in claim 2, the determination threshold value may be set according to a use environment assumed in advance. In this way, the judgment threshold is changed according to the use environment (for example, the outside air temperature, the frequency of start control, etc.) preliminarily assumed in the design stage or the manufacturing stage, and the integrated value of the interruption time of the event frame is changed. The sensitivity when storing the diagnosis code can be changed to the sensitive side or the insensitive side.

  Further, as in claim 3, when the integrated value of the interruption time of the event frame exceeds the determination threshold value, a diagnostic code for the event frame is stored, and the periodic frame transmitted periodically from other control means is stored. When reception is interrupted, a diagnostic code for a regular frame may be stored. In this way, the event frame diag code and the regular frame diag code can be distinguished and stored, and it is possible for the dealer or the like to identify the abnormality of the vehicle at an early stage.

  Further, as in claim 4, the integrated value of the event frame interruption time may be stored in a non-volatile memory (a rewritable memory that retains stored data even when the starting control means is powered off). In this way, the integrated value of the event frame interruption time can be held even when the internal combustion engine is stopped (when the control means for starting is turned off), and the event frame interruption time can be maintained during the next start control. Without resetting the integrated value, the integrated value of the interruption time of the event frame can be updated following the previous start control.

FIG. 1 is a diagram showing a schematic configuration of an engine start control system in one embodiment of the present invention. FIG. 2 is a time chart showing an execution example of the abnormality diagnosis of this embodiment. FIG. 3 is a flowchart showing the flow of processing of the start control main routine. FIG. 4 is a flowchart showing the flow of processing of the cranking control routine. FIG. 5 is a flowchart showing the flow of processing of the reception state determination routine. FIG. 6 is a flowchart showing the flow of processing of the diagnostic code storage processing routine. FIG. 7 is a time chart showing an execution example of the abnormality diagnosis of the comparative example.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, a schematic configuration of the engine start control system will be described with reference to FIG.
A power management ECU 12 (starting control means) is provided separately from an engine ECU 11 (other control means) that controls an engine (not shown) that is an internal combustion engine.

  The output signal of the push switch 13, the output signal of the current sensor 15 for detecting the charging current of the battery 14, the voltage sensor 16 for detecting the battery voltage (voltage of the battery 14), and the like are input to the power management ECU 12. The power management ECU 12 includes a power supply switching unit 17 that controls the power state of the entire vehicle electrical system, a start control unit 18 that controls engine start, a charge control unit 19 that controls charging of the battery 14, and the like. .

  On the other hand, output signals from the coolant temperature sensor 20 that detects the coolant temperature of the engine and the rotation speed sensor 21 that detects the engine rotation speed NE are input to the engine ECU 11. The engine ECU 11 includes a start control unit 22 and a complete explosion determination unit 23 that performs a complete explosion determination of the engine. The start control unit 22 of the engine ECU 11 serves as a counter referred to by the complete explosion determination unit 23, and the start control unit 18 of the power management ECU 12 mainly plays a role of controlling the start of the engine. ing.

  The power management ECU 12 and the engine ECU 11 transmit and receive necessary information through CAN communication. A starter SW flag indicating that the push switch 13 is turned on is transmitted from the power management ECU 12 to the engine ECU 11. On the other hand, vehicle information (engine state, transmission state, etc.), engine speed NE, cooling water temperature, starter-off request flag, etc. are transmitted from the engine ECU 11 to the power management ECU 12.

  When the push switch 13 is turned on and the switch-on signal SSW is input to the power switching unit 17, the power management ECU 12 inputs the engine start request signal STSW from the power switching unit 17 to the start control unit 18. The start control unit 18 supplies drive current to the starter relay 24 based on the engine start request signal STSW to turn on the starter relay 24. Thereby, electric power is supplied from the battery 14 to the starter 25, and engine cranking is started. While the engine start request signal STSW is continued, the start control unit 18 supplies a drive current to the starter relay 24 and performs cranking unless the starter off request flag is input from the complete explosion determination unit 23 of the engine ECU 11. If a starter-off request flag is input from the complete explosion determination unit 23, supply of drive current to the starter relay 24 is stopped, the starter relay 24 is turned off, and engine cranking is stopped. To do.

  In this embodiment, the engine ECU 11 transmits an event frame to the power management ECU 12 only during cranking by CAN communication, and periodically transmits a periodic frame to the power management ECU 12 while the power is on.

Further, the power management ECU 12 executes each routine shown in FIGS. 3 to 6 to be described later. When reception of the event frame is interrupted during cranking, the power management ECU 12 accumulates the event frame interruption time to obtain the event frame. Even if the event frame is received, the accumulated value of the interruption time of the event frame is held without being cleared, and when the accumulated value of the interruption time of the event frame exceeds a predetermined determination threshold, an abnormality diagnosis is performed in which a diagnosis code is stored.

Hereinafter, an execution example of the abnormality diagnosis of the present embodiment will be described with reference to FIG.
First, it is determined whether or not reception of an event frame has been interrupted during cranking during start-up control. If it is determined that the event frame has been received normally, the event frame reception status flag is determined at that time t1. Is set to “OK”, and the diagnostic code storage flag is set to “OK”.

  After that, if it is determined that event frame reception has been interrupted during cranking, the event frame reception status flag is reset to “ERROR” at that time t2, and the event frame interruption time is integrated during cranking. Then, an integrated value of the event frame interruption time is obtained, and the integrated value of the event frame interruption time is stored in a rewritable nonvolatile memory such as a backup RAM (not shown) (stored data even when the power management ECU 12 is powered off). Stored in a rewritable memory. If the integrated value of the interruption time of the event frame does not exceed a predetermined determination threshold, the diagnostic code storage flag is maintained at “OK”.

  Since the integrated value of the event frame interruption time is stored in a non-volatile memory such as a backup RAM, the integrated value of the event frame interruption time is obtained even when the engine is stopped after the engine is operated (while the power management ECU 12 is powered off). Retained.

  Thereafter, it is determined whether or not the event frame has been received again during cranking at the next start control, and at the time t3 when it is determined that the event frame has been received normally, the event frame reception status flag and the diagnosis are displayed. The code storage flag is set to “OK”, and at the time t4 when it is determined that event frame reception has been interrupted during cranking, the event frame reception status flag is reset to “ERROR” and during cranking. An integrated value of the interruption time of the event frame is obtained, and the integrated value of the interruption time of the event frame is stored in a non-volatile memory such as a backup RAM.

  After that, when the integrated value of the interruption time of the event frame exceeds a predetermined determination threshold value, the diag code storage flag is reset to “ERROR” at the time t5, and then a predetermined diag code storage process is assumed. The diagnostic code is stored at time t6 when a predetermined time has elapsed since the condition was established.

  The abnormality diagnosis of the present embodiment described above is executed by the power management ECU 12 according to the routines shown in FIGS. Hereinafter, the processing content of each of these routines will be described.

[Start control main routine]
The start control main routine shown in FIG. 3 is repeatedly executed at a predetermined cycle when the push switch 13 is turned on (when the switch on signal SSW is input). In this case, the ON operation of the push switch 13 is, for example, a so-called short press that is pushed for a short time. When this routine is started, first, in step 101, a cranking control routine shown in FIG. 4 described later is executed, and in a next step 102, a diagnostic code storage processing routine shown in FIG. 6 described later is executed.

[Cranking control routine]
The cranking control routine shown in FIG. 4 is a subroutine executed in step 101 of the start control main routine of FIG. When this routine is started, first, in step 201, each flag (event frame reception state flag, cranking control flag, diagnostic code storage flag) is executed by executing a reception state determination routine of FIG. Are each set to “OK” or reset to “ERROR”.

  Thereafter, the process proceeds to step 202, where it is determined whether or not the cranking control flag is “OK”. If it is determined that the cranking control flag is “OK”, the reception state is normal. If it is determined that there is, the process proceeds to step 203 to shift to normal control.

  On the other hand, if it is determined in step 202 that the cranking control flag is not “OK” (that is, the cranking control flag is “ERROR”), it is determined that the reception state is abnormal. Then, the process proceeds to step 204, and the process shifts to fail-safe control by a direct line, a timeout, or the like.

  Thereafter, the process proceeds to step 205, and whether or not the cranking stop condition is satisfied is determined by, for example, information transmitted from the engine ECU 11 (starter-off request flag, cooling water temperature, engine speed NE) or the power management ECU 12. The determination is made based on the measured cranking continuation time or the like.

  If it is determined in step 205 that the cranking stop condition is not satisfied, the process proceeds to step 206, where the drive current is supplied to the starter relay 24 and the starter relay 24 is turned on. Thereby, electric power is supplied to the starter 25 to start or continue the cranking of the engine.

  Thereafter, if it is determined in step 205 that the cranking stop condition is satisfied, the process proceeds to step 207, where the supply of drive current to the starter relay 24 is stopped and the starter relay 24 is turned off. To do. Thereby, the power supply to the starter 25 is stopped, and the cranking of the engine is stopped.

[Reception status judgment routine]
The reception state determination routine shown in FIG. 5 is a subroutine executed in step 201 of the cranking control routine of FIG. When this routine is started, it is first determined in step 301 whether or not cranking is being performed. If it is determined that cranking is being performed, the process proceeds to step 302 where reception of an event frame is interrupted. Determine whether or not.

  If it is determined in step 302 that the reception of the event frame is not interrupted (the event frame is normally received), the process proceeds to step 303 and the event frame reception state flag is set to “OK”. .

  On the other hand, if it is determined in step 302 that reception of the event frame has been interrupted, the process proceeds to step 304, the event frame reception state flag is reset to “ERROR”, and then the process proceeds to step 305. The interruption time of the event frame is integrated to obtain an integrated value of the interruption time of the event frame, and the integrated value of the interruption time of the event frame is stored in a non-volatile memory such as a backup RAM.

  Thereafter, if it is determined in step 301 that cranking is not in progress, the process proceeds to step 306, where the previous event frame reception status flag is held (that is, the event frame reception status flag at the end of the previous cranking is set). Hold).

  Thereafter, the process proceeds to step 307, in which it is determined whether the event frame reception status flag is “ERROR” or the periodic frame reception status flag is “ERROR”. Here, the periodic frame reception status flag is set to “OK” when it is determined that the reception of the regular frame is not interrupted (the regular frame is normally received). On the other hand, when it is determined that the reception of the regular frame is interrupted, the regular frame reception state flag is reset to “ERROR”.

  If it is determined in step 307 that the event frame reception status flag is “ERROR” or the periodic frame reception status flag is “ERROR”, the state continues for a predetermined time, and then the process proceeds to step 308. The ranking control flag is reset to “ERROR”.

  On the other hand, if it is determined in step 307 that the event frame reception state flag is “OK” and the periodic frame reception state flag is “OK”, the state continues for a predetermined time, and then the process goes to step 309. Then, the cranking control flag is set to “OK”.

  Thereafter, the process proceeds to step 310, and it is determined whether or not the integrated value of the event frame interruption time exceeds a predetermined determination threshold value. Here, the determination threshold is set in accordance with the use environment (for example, the outside air temperature, the frequency of start control, etc.) assumed in advance in the design stage, the manufacturing stage, or the like.

  If it is determined in step 310 that the integrated value of the event frame interruption time exceeds the determination threshold value, the process proceeds to step 312 to reset the diag code storage flag to “ERROR”.

  On the other hand, if it is determined in the above step 310 that the integrated value of the interruption time of the event frame is equal to or less than the determination threshold value, the process proceeds to step 311 to determine whether or not the periodic frame reception state flag is “ERROR”. If it is determined that the periodic frame reception state flag is “ERROR”, the process proceeds to step 312 to reset the diag code storage flag to “ERROR”.

  On the other hand, if it is determined in step 310 that the accumulated value of the interruption time of the event frame is equal to or less than the determination threshold value and it is determined in step 311 that the periodic frame reception state flag is “OK”, In step 313, the diagnosis code storage flag is set to “OK”.

[Diagnostic code storage routine]
The diagnostic code storage processing routine shown in FIG. 6 is a subroutine executed in step 102 of the start control main routine of FIG. When this routine is started, first, in step 401, it is determined whether or not a predetermined condition for storing a diagnostic code is satisfied based on, for example, the following conditions (1) to (3).

(1) The IG switch is ON (power ON)
(2) The battery voltage is higher than the specified value
(3) The starter 25 is OFF (the starter 25 is stopped)

If all of these conditions (1) to (3) are satisfied, the preconditions for diag code storage processing are satisfied, but there are conditions that do not satisfy any one of the above conditions (1) to (3). In this case, the precondition for the diagnosis code storing process is not satisfied.
If it is determined in step 401 that the precondition for the diag code storage process is not satisfied, the present routine is terminated without executing the processes in and after step 402.

  On the other hand, if it is determined in step 401 that the preconditions for the diag code storage process are satisfied, the processes after step 402 are executed as follows. First, in step 402, it is determined whether or not the diagnostic code storage flag is “ERROR”. If it is determined that the diagnostic code storage flag is “OK”, the diagnostic code is not stored. This routine is terminated.

  On the other hand, if it is determined in step 402 that the diagnosis code storage flag is “ERROR”, the state continues for a predetermined time, and then the process proceeds to step 403 where the diagnosis code is stored in a non-volatile memory such as a backup RAM. And the routine is terminated.

In the present embodiment described above, in the system in which the power management ECU 12 receives an event frame transmitted only during cranking from the engine ECU 11 by CAN communication, when the reception of the event frame is interrupted during cranking, Even if the event frame is received, the accumulated value of the interruption time of the event frame is held without being cleared, and the accumulated value of the interruption time of the event frame exceeds a predetermined judgment threshold. The error diagnosis that memorizes the code was performed, so the event frame interruptions occurred frequently or the event frame interruptions continued for a long time, and the integrated value of the event frame interruption time exceeded the judgment threshold If it is determined that an abnormality has occurred, store the diagnosis code Can, it is possible to improve the accuracy of the diagnosis code storing process based on the reception state of the event frame (abnormality diagnostic accuracy).

  For example, if it is determined only once that the reception of the event frame has been interrupted for a short time immediately before the end of cranking, the integrated value of the event frame interruption time does not exceed the determination threshold value, and thus an abnormality has occurred. The diagnosis code is not memorized. As a result, the diag code is stored unnecessarily when it is determined that the reception of the event frame is interrupted only once for a short time just before the end of the cranking even though no abnormality has actually occurred. Can be prevented. As a result, when the vehicle is inspected by a dealer or the like, it is not necessary to perform unnecessary work by storing unnecessary diagnostic codes.

  Further, when reception of an event frame is temporarily interrupted during cranking, if the integrated value of the event frame interruption time exceeds a determination threshold, it is determined that an abnormality has occurred and a diagnosis code is stored. As a result, even after an event occurs during cranking and the reception of the event frame is interrupted, the diag code can be stored even when the event frame reception state returns to normal before the cranking ends.

  In this embodiment, since the determination threshold is set according to the use environment (for example, the outside air temperature and the frequency of start control) assumed in advance in the design stage, the manufacturing stage, etc., the design stage, the manufacturing stage, etc. By changing the determination threshold according to the use environment assumed in (1), the sensitivity when storing the diag code with respect to the integrated value of the interruption time of the event frame can be changed to the sensitive side or the insensitive side.

  Furthermore, in the present embodiment, since the integrated value of the event frame interruption time is stored in a non-volatile memory such as a backup RAM, the event frame interruption time is also maintained even when the engine is stopped (while the power management ECU 12 is powered off). The accumulated value can be retained, and the accumulated value of the event frame interruption time can be updated at the time of the next start control without resetting the integrated value of the event frame interruption time. it can.

  In the above embodiment, there is no distinction between the case where the integrated value of the interruption time of the event frame exceeds the determination threshold and the case where the periodic frame reception status flag is “ERROR” (when reception of the periodic frame is interrupted). However, the present invention is not limited to this. For example, when the integrated value of the interruption time of the event frame exceeds the determination threshold, the diagnostic code for the event frame is stored, and the periodic frame is stored. If the reception of the frame is interrupted, a diagnostic code for a regular frame may be stored. In this way, the event frame diag code and the regular frame diag code can be distinguished and stored, and it is possible for the dealer or the like to identify the abnormality of the vehicle at an early stage.

  In the above embodiment, the present invention is applied to a system that uses a power management ECU as a starting control means. However, the present invention is not limited to this, and a control circuit other than the power management ECU (for example, an integrated verification ECU) is used for starting. The present invention may be applied to a system used as a control means.

  DESCRIPTION OF SYMBOLS 11 ... Engine ECU (Other control means), 12 ... Power management ECU (Starting control means), 13 ... Push switch, 14 ... Battery, 18 ... Start-up control part, 24 ... Starter relay, 25 ... Starter

Claims (4)

In an internal combustion engine start control device comprising start control means for performing start control of an internal combustion engine and receiving an event frame transmitted during cranking from other control means by CAN communication,
The start-up control means accumulates the event frame interruption time when reception of the event frame is interrupted during the cranking, and accumulates the event frame interruption time even if the event frame is received. An internal combustion engine start control device characterized in that a value is held without being cleared, and an abnormality diagnosis is performed in which a diagnosis code is stored when an integrated value of interruption times of the event frame exceeds a predetermined determination threshold value.   The start control device for an internal combustion engine according to claim 1, wherein the determination threshold value is set according to a use environment assumed in advance.   The starting control means stores a diag code for an event frame when the integrated value of the interruption time of the event frame exceeds the determination threshold, and is periodically transmitted from the other control means. The internal combustion engine start control device according to claim 1 or 2, wherein a diagnostic code for a regular frame is stored when reception of the frame is interrupted.   4. The start control device for an internal combustion engine according to claim 1, wherein the start control means stores an integrated value of the interruption time of the event frame in a nonvolatile memory.

Images