JP5441557B2 - Abnormality diagnosis device - Google Patents

Description

  The present invention relates to an abnormality diagnosis device that detects and diagnoses an abnormality in an energization control device that controls energization to a load such as a glow plug.

  Conventionally, as an abnormality detection device that detects an abnormality in a glow plug energization control device that assists ignition of a diesel engine, Patent Literature 1 provides a plurality of power supply lines that supply power from a battery to a plurality of glow plugs. A plurality of switch means for switching between energization and non-energization of the glow plug, and a timing for turning one of the plurality of switch means on and another one or more switch means off. Control means capable of controlling, energization state detection means for detecting an energization state from the battery to the glow plug in a state in which the timing control by the control means is performed, and detection by the energization state detection means Abnormality determination means for determining an energization abnormality of a part of the plurality of glow plugs based on the result , The abnormality detection apparatus is disclosed which comprising the.

  In the conventional abnormality detection device as disclosed in Patent Document 1, the battery voltage is detected when a switching means such as an FET is turned on to detect the presence or absence of a short circuit of the energization line, and the current sensor is detected when the switching means is turned on. Disconnection is detected by detecting the amount of current, output voltage is detected by using a shunt resistor, and interruption and overcurrent are detected.

On the other hand, in recent years, low-rated ceramic glow plugs have been adopted in order to improve the quick warmth of the glow plugs and exhaust emissions. However, if a short circuit occurs in the switch means and current is continuously applied from the power supply line directly to the ceramic glow plug without being restricted by the switch means, the ceramic glow plug may be damaged due to thermal runaway.
For this reason, when a short circuit occurs in the switch means, the energization to the glow plug must be surely cut off.

In addition, when a plurality of switch means are provided, water drops adhere to bridge between the output terminals of the plurality of switch means or between the input terminals due to the occurrence of condensation during cold start, and a short circuit occurs between the switch means. May occur.
When a short circuit occurs between the switch means due to the adhesion of water droplets, there is no abnormality in the switch means itself, and if the current to the load can be maintained, the water drops generated by condensation will evaporate during that time, It may return to the state.
Furthermore, there is a possibility that a short circuit may occur between the wirings, that is, between the switch means due to the inclusion of the wirings. Even in such a case, the normal state may be restored by vibration or the like.
Therefore, considering the convenience of the driver, it is not always desirable to stop energization uniformly when a short circuit abnormality occurs between the switch means.

However, in the conventional abnormality detection device as disclosed in Patent Document 1, it is not assumed that a short circuit abnormality occurs between a plurality of switch means, but the switch means itself is short-circuited or occurs between a plurality of switch means. I can't tell if it's a short circuit.
In addition, when a short circuit occurs between a plurality of switches, the glow plug may be destroyed due to excessive energization of the glow plug.
Therefore, in a conventional abnormality detection device that cannot distinguish between a short circuit of the switch means itself and a short circuit between a plurality of switch means, the switch means is not an abnormality of the switch means, but is a temporary failure and can be recovered between adhering water drops. Even in the case of short-circuiting, the energization must be stopped uniformly as in the case where a short-circuit occurs in the switch means.

  Even if a short circuit occurs between a plurality of switch means, other glow plugs may be able to drive normally, so even if a short circuit abnormality occurs between a plurality of switch means in order to enable retreat travel There is also a demand to continue energizing the glow plug as much as possible.

  Also, when starting a diesel engine, energization is started at the same time for both the starter and the glow plug, which have a large rush current, for cranking, so noise is likely to occur and abnormally occurs due to the effects of noise. There is also a risk that the diagnostic device malfunctions.

  Therefore, in view of such a situation, the present invention eliminates the influence of noise in an abnormality diagnosis device used for energization control that controls energization to a plurality of loads by opening and closing switch means provided for each load. A short circuit abnormality is detected, and when a short circuit abnormality is detected, it is determined whether it is a short circuit between a plurality of switch means or a short circuit occurring inside the switch means, and according to the cause of the short circuit abnormality An object of the present invention is to provide an abnormality diagnosis device that enables selection of energization control.

According to a first aspect of the present invention, there is provided a power source, a switch unit that is provided for each load with respect to a plurality of loads, and controls the supply and stop of power from the power source to the load by opening and closing, and the switching of the switch unit A drive signal transmission means for transmitting a drive signal to be transmitted; and a drive control means for opening and closing the switch means in accordance with the drive signal, and detecting and diagnosing an abnormality in the power supply control device that controls the power supply to the load. In the abnormality diagnosis device,
Output abnormality detection means for detecting an output abnormality of each switch means is provided for each of the plurality of switch means, and when one switch means is opened according to the drive signal among the plurality of switch means, the switch means Primary determination means for determining presence / absence of output abnormality of the means by the output abnormality detection means, and after determining the output abnormality by the primary determination means, the drive signal of the switch means in which the abnormality has occurred is stopped, and the other switch And an alternative energization unit that attempts to energize a plurality of loads by opening and closing the switch unit in which the drive signal is stopped by a drive signal that opens and closes the unit (claim 1).

In the second invention, the primary determination means is an element open output detection means for detecting an output when the switch means is in an open state, and an element open detection time for determining a detection result of the element open output detection means. Whether there is a false detection by comparing the output number, the number of abnormalities detected by the output determination means when the element is open, and the number of abnormalities counted by the abnormality number counting means and the threshold Erroneous detection determination means for determining whether or not .

In the third invention, when the primary determination means determines that the output is abnormal, the drive signal is stopped, all of the plurality of switch means are temporarily opened, and the output abnormality is detected by the primary determination means. The switch means is provided with secondary determination means for determining again whether or not there is an output abnormality by the output abnormality detection means (claim 3).

According to a fourth invention, in the third invention, the secondary determination means is a drive signal stop means for stopping the drive signal, and the switch means in a state where the drive signal is stopped by the drive signal stop means. Output detection means for detecting the output of the element drive, and output determination means for the element drive stop when determining the detection result of the element drive stop output detection means. The primary determination means determines that the output is abnormal. And, when it is determined that the output is abnormal by the drive stop output determining means, it is determined that the element is short-circuited, the primary determination means is determined to be abnormal output, and the output is determined by the drive stop output determining means. If it is determined that there is none, it is determined that the element is short-circuited.

In 5th invention, in 3rd or 4th invention, the alternative electricity supply process by the said alternative electricity supply means is implemented after the said primary determination and before the said secondary determination, or after the said secondary determination ( Claim 5).

According to a sixth invention, in any one of the third to fifth inventions, a substitute output number counting means for counting the number of substitute outputs outputted in a state where the drive signal is stopped by the substitute energization means and the number of substitute outputs. The tertiary determination means for determining whether or not the alternative energization process is being performed by comparing the number of alternative outputs counted by the counting means and the threshold value, and when the alternative output is not detected during the alternative energization process, an inter-element short circuit is detected. When the inter-element short-circuit elimination determining means that determines that the inter-element short-circuit elimination determination means determines that the inter-element short-circuit elimination determination means is resolved, the drive signal stop is canceled and the normal energization control is resumed. Normal return means (claim 6).

According to a seventh aspect, in any one of the first to sixth aspects, the load is a glow plug that is provided for each cylinder of the diesel engine and that assists ignition by heating the air-fuel mixture.

According to the first aspect of the present invention, the drive signal to the switch means determined to have some short circuit abnormality in the primary determination is stopped, and alternative energization is attempted by the other switch means not stopped. If the detected short-circuit abnormality is an inter-element short circuit that occurs across a plurality of elements, the switch means in which the drive signal is stopped is connected to the other switch means via the inter-element short circuit when an alternative energization is performed. Because it is driven to open and close by the drive signal that drives the power supply, it does not extend the energization time due to the overlap of the duty time, and it is appropriate to maintain the energization continuously and not supply excessive power to the load where the short circuit between elements occurred. It can be driven with a sufficient amount of power.
On the other hand, in the case of an in-element short circuit in which a short circuit has occurred in the switch means, the drive signal of the channel in which no abnormality has occurred is transmitted to the channel in which an abnormality has occurred even if alternative energization is attempted. In other words, when the energization of the channel in which the abnormality has occurred is stopped, the load in which the in-element short circuit has occurred is not energized.

According to the second aspect of the invention, it is possible to prevent a single erroneous detection of an output abnormality due to the influence of noise or the like by determining an output abnormality only when the number of abnormality detections is equal to or greater than a threshold value. Therefore, the reliability as an abnormality diagnosis device is improved.

According to the third invention, it is possible to determine whether the output abnormality of the switch means is due to an intra-element short-circuit abnormality or an inter-element short-circuit abnormality. This can be selected as appropriate.

According to the fourth aspect of the present invention, it is possible to sequentially perform abnormality diagnosis for the plurality of switch means by the primary determination means and the secondary determination means, and to identify the switch means in which an abnormality has occurred. For example, when an internal short circuit has occurred, the switch means has been destroyed and cannot be recovered. Therefore, if the internal short circuit is determined, the drive signal transmitting means indicates that the internal short circuit has occurred. It is possible to transmit a next determination signal and provide an energization cut-off means to immediately cut off the energization to the load to prevent damage to the load, or to send an alarm to prompt the exchange of the switch means.
In addition, the short circuit between elements is a state in which there is no abnormality in the switch means itself, and a short circuit is generated between a plurality of elements, and it may be possible to control energization to the load.
Therefore, when it is determined that the element is short-circuited, it is possible to resume transmission of the drive signal and continue energization of the load. In this case, since the plurality of switch means in which the short circuit between elements drives each other's load, the duty time overlaps and the energization time to each load becomes long. It is also possible to optimize the amount of energized power by correcting the signal to be short.

  In the fifth invention, when the alternative energization process is performed after the primary determination and before the secondary determination, the alternative energization process is performed immediately without waiting for the completion of the secondary determination. If the alternative energization process is performed after the secondary determination, it is determined that the short-circuit abnormality occurring due to the secondary determination is an element-to-element short-circuit and alternative energization is possible. Alternative energization is carried out only when

  According to the sixth aspect of the invention, the output of the switch means that has stopped the drive signal during the alternative energization period is not determined as an abnormal output, but is determined to be due to the alternative energization, the energization is continued, and the short circuit between the elements Is eliminated and the switch means can be driven normally, the stopped drive signal can be resumed to return to normal energization control.

  According to the seventh aspect of the invention, it is possible to perform highly reliable abnormality diagnosis without erroneous detection even during cranking where noise is likely to occur, and in addition, in-element short circuit that may lead to damage to the glow plug. On the other hand, the power supply is cut off immediately to prevent damage to the glow plug, and in the situation where the glow plug rating has a margin against the short circuit between elements, the current supply control is performed for all cylinders. On the other hand, in situations where there is not enough room for the rating of the glow plug, processing with a high degree of freedom is possible, such as stopping energization only to the glow plug in which a short circuit between elements has occurred, and an abnormality diagnosis device used in the glow plug energization control device As reliability improves.

The block diagram which shows the outline | summary of the whole electricity supply control apparatus containing the abnormality detection apparatus in embodiment of this invention. The abnormality detection flowchart applied to the abnormality detection apparatus in the 1st Embodiment of this invention. The time chart which shows the effect with respect to the short circuit in an element of the abnormality detection apparatus in the 1st Embodiment of this invention. The time chart which shows the effect with respect to the short circuit between elements of the abnormality detection apparatus in the 1st Embodiment of this invention. The abnormality processing flowchart at the time of determining with the short circuit between elements applied to the abnormality detection apparatus in the 1st Embodiment of this invention. The time chart which shows the effect with respect to the short circuit between elements of the abnormality detection apparatus in the 1st Embodiment of this invention. The abnormality processing flowchart at the time of determining with the short circuit between elements applied to the abnormality detection apparatus in the 2nd Embodiment of this invention. The abnormality processing flowchart at the time of the short circuit abnormality detection applied to the abnormality detection apparatus in the 3rd Embodiment of this invention. The abnormality detection flowchart applied to the conventional abnormality detection apparatus shown as a comparative example. The time chart which shows the operation | movement with respect to the short circuit in an element of the conventional abnormality detection apparatus as a comparative example. The time chart which shows the problem of the action | operation with respect to the short circuit between elements of the conventional abnormality detection apparatus as a comparative example.

Referring to FIG. 1, as an abnormality diagnosis device in an embodiment of the present invention, an electronic control unit (ECU) 20 that controls the operation of a diesel engine is driven with a glow plug 50 attached to each cylinder of the diesel engine as a load. An abnormality diagnosis device (DIU) 34 applied to the glow plug energization control device 1 that controls energization to the load according to the drive signal SI transmitted from the ECU 20 as a signal transmitting means will be described as an example.
In the present embodiment, the case of a four-cylinder engine is illustrated, but the present invention is not limited to this embodiment. The present invention is particularly suitable as an abnormality diagnosis device in a glow plug energization control device using a low-rated ceramic glow plug as a load, but can be applied to all energization control devices that control a plurality of loads.

  As shown in FIG. 1, the glow plug energization control device 1 is provided for each cylinder of an unillustrated diesel engine, and a glow plug 50 that heats the air-fuel mixture and assists ignition is used as a load to supply power to the glow plug 50. A power source 10 such as an in-vehicle battery as a source, a key switch 11 that opens and closes the power source 10, an electronic control unit (ECU) 20, and an energization control unit (GCU) 30 that controls energization to the glow plug 50. ing.

The energization control unit (GCU) 30 includes a plurality of switch means 31 (MOS ₁ , MOS ₂ , MOS ₃ , MOS ₄ ) provided for each load, and a drive signal SI transmitted from the ECU 20 to each switch means 32. A drive control means (DCU) 32 for transmitting drive signals G ₁ , G ₂ , G ₃ , G ₄ for driving opening and closing, and an output abnormality detection means 33 provided for each switch means, a potential on the output side of the switch means 31. Output potential detecting means for detecting the abnormality, and an abnormality diagnosing device (DIU) 34 for judging abnormality based on the result detected by the output abnormality detecting means 33.

  The DIU 34, which is the main part of the present invention, is a primary determination means (S100 to S104) for determining the presence or absence of a short circuit abnormality, and when a short circuit abnormality is detected, whether the cause is due to an internal short circuit or an inter-element short circuit. Secondary determination means (step 105 to step 110) for identifying whether the error occurs.

For the switch means 31, a power semiconductor device such as a power MOSFET or IGBT is used.
The ECU 20 transmits a drive signal SI to the GCU 30 in order to control the energization to the glow plug 50 in accordance with the operation state of the diesel engine, and is turned on / off from the DCU 32 to the gate G of the switch means 31 according to the drive signal SI. driving voltage V _G is applied in a pulsed state, the switch means 31 is opened and closed. In order to adjust the heat generation timing of the glow plug 50 provided in each cylinder according to the operating state of the engine, the DCU 32 outputs the drive voltage V _G from G _{1 to} G _{4 while} shifting the timing at a predetermined interval. .

With reference to FIG. 2, the abnormality detection method which can identify the cause of occurrence of the abnormality applied to the glow plug energization control device 1 in the first embodiment of the present invention will be described.
In Step 100 to Step 104, determination as to whether or not there is any short-circuit abnormality is performed as a primary determination unit.
The element open output detection means in step 100 is provided as an output abnormality detection means 33 when the switch means 31 opened / closed by the drive control means (DCU) 32 is opened according to the drive signal SI from the ECU 20. The output potential detection means detects the presence or absence of output in a state where the switch means 31 is opened (off state). As a specific configuration of output abnormality judging means it may detect the presence or absence of an output by comparing the output voltage V _SS and the input voltage V _DD of the detected output side by the output detection means.
Next, the element open output determination means in step 101 determines the detection result in step 100. If the battery voltage V _DD is detected on the output side of the switching element 31 in step 100, the output level becomes Hi even though the switch means 31 is in the OFF state, so that some abnormality may occur. It is determined that there is, and the process proceeds to step 102.
Next, the number of abnormality detections n is counted by the abnormality number counting means in step 102. In the erroneous detection determination means in step 103, the abnormality detected in step 101 is due to erroneous detection due to the influence of noise depending on whether or not the number n of abnormality detected is equal to or less than a threshold value (for example, 5 times). Or whether an abnormality is truly detected.
If the number of abnormality detections n is less than or equal to the threshold value, there is a risk of erroneous detection. Therefore, the determination in step 103 is Yes, and the process returns to step 100. Check if there is any output when is off.
If an abnormality is detected for some reason, Step 100 to Step 103 are repeated, and the abnormality detection count n is increased each time an abnormality is detected.
If the battery voltage V _DD is not detected on the output side of the switching element 31 in step 100, the output level in step 101 is Lo, and it is determined that there is no abnormality, and the process proceeds to step 102.
At this time, if the abnormality detection count n is 1 or more and less than or equal to the threshold value, and the output level of step 101 is Lo, the abnormality detected in step 103 earlier is due to erroneous detection. The number of abnormality detections n counted so far is reset to 0 by the count initialization means in step 104.
Further, returning to step 100, the determination as to whether or not an abnormal output is detected when the next drive signal SI is opened or closed is repeated.
If the number of abnormality detections n exceeds the threshold value in step 103, it is determined that the abnormality is not due to erroneous detection, but that a true abnormality has occurred, and the determination in step 103 is No. Proceed to 110 secondary determination means. At this time, a primary determination signal DI ₁ indicating that some abnormality has occurred is transmitted.
In the secondary determination means from step 105 to step 110, whether the output abnormality detected by the primary determination means is due to an internal short circuit in which a short circuit has occurred in the switch means 31, or a short circuit has occurred between the plurality of switch means 31. It is determined whether this is due to a short circuit between the elements.
The drive signal stop means in step 105 receives the primary determination signal DI ₁ transmitted from the primary determination means described above, and temporarily transmits the drive signal SI or outputs the drive voltage V _G from the drive control means 32. And all of the plurality of switch means 31 are simultaneously opened.
Next, in the element driving stop output detecting means in step 106, the presence or absence of output when all the switch means 31 are in the open state is detected by the output potential detecting means provided as the output abnormality detecting means 32.
In the element driving stop output determination means in step 107, when all the switch means 31 are in the open state and the battery voltage V _DD is detected on the output side in step 106, the output level in step 107 becomes Hi, Proceed to 108.
In the intra-element short-circuit determination in step 108, the output level Hi is detected even though all the switch means 31 are not operating at all. Therefore, the inside of the element in which the short-circuit abnormality has occurred inside the switch means 31. Judged as a short circuit.
In the element drive stop output determination means in step 107, when all the switch means 31 are open and the battery voltage V _DD is not detected on the output side in step 106, the output level in step 107 becomes Lo. Proceed to step 109.
In the inter-element short-circuit determination at step 109, the output level of step 101 is Hi when the switch means 31 to be detected by the primary determination means is in the open state and the other switch means 31 is driven to open and close. Nevertheless, when all the switch means 31 are open in the secondary determination means, the output level is Lo in step 107, so that the switch means 31 itself has no abnormality and a plurality of It is determined that the short circuit between the elements in which the short circuit abnormality has occurred between the switch means 31.
From the above, it is determined whether the output abnormality of the switch means 31 is due to an intra-element short-circuit abnormality or an inter-element short-circuit abnormality, and the result is transmitted to the ECU ₂₀ as a secondary determination signal DI2.
In addition, the primary determination means and the secondary determination means can sequentially perform abnormality diagnosis on the plurality of switch means 32 to identify the switch means in which an abnormality has occurred.
In step 110, in response to the secondary determination signal DI _2, it is possible to appropriately select whether the subsequent processing in any way.
For example, if an internal short circuit has occurred, the switch means 31 has been destroyed and cannot be restored. If it is determined in step 108 that the internal circuit short circuit has occurred, the ECU 20 is informed of the internal short circuit. A secondary determination signal DI ₂ is transmitted, and the relay 40 provided as a power cut-off means is opened (break), and the power supply to the glow plug 50 is immediately cut off to prevent damage to the load, or an alarm is sent. The switch means 31 or the GCU 30 can be exchanged.

Further, the short circuit between the elements is a state in which there is no abnormality in the switch means 31 itself and a short circuit is generated between a plurality of elements, and it may be possible to control energization to the load.
Therefore, when it is determined in step 109 that the element is short-circuited, in step 110, transmission of the drive signal SI can be resumed, and energization to the load (glow plug) 50 can be continued.
In this case, since the plurality of elements in which the short circuit between the elements occurs drives each other's load, the duty time overlaps and the energization time to each load becomes long. It is also possible to optimize the amount of heat generated by correcting _d short.
In addition, for example, when a short circuit between elements occurs due to the attachment of water droplets due to condensation, the water droplets evaporate while continuing energization, and the state of the short circuit between elements is eliminated, and normal energization control is entered. It is also possible to do.
When it is determined that the short circuit between the elements is determined, the switch unit 31 in which the short circuit between the elements is generated may be stopped, and the other switch unit 31 may perform a process of selecting a normal opening / closing drive. Specific processing after the secondary determination will be described later.

The effect of the first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 3A, when an in-element short circuit occurs in the switch means 31 (MOS), the input terminal D and the output terminal S are short-circuited. The operations by the primary determination means in steps 100 to 104 correspond to FIGS. (B) to (d), and the operations by the secondary determination means in steps 105 to 110 correspond to the drawings (e) to (g). ).
As shown in the figure (b), for example, the PWM control or the like, in a state in which the drive signal SI to turn on and off at a predetermined duty time t _d and the period T is transmitted, the elements in the short circuit occurs, the view ( As shown in c), the output voltage V _SS becomes a potential (Hi) substantially equal to the input voltage V _DD regardless of whether the drive signal SI is on or off.
In this state, the output voltage V _SS is detected by the output abnormality detection means 32 at the falling timing of the drive signal SI, and the primary determination signal DI ₁ is transmitted as shown in FIG. When the primary determination signal DI ₁ is transmitted each time the drive signal SI is turned on and off and the abnormality detection count n is detected more than a threshold value (for example, 5 times), the drive signal SI is stopped as shown in FIG. .
When the output voltage _VSS is detected in this state, the output level Hi is detected although the drive signal SI is in the complete stop state as shown in FIG. Then, it is determined that there is an intra-element short circuit, and a secondary determination signal DI ₂ indicating that there is an intra-element short circuit is transmitted. When it is determined by the secondary determination means that the element is short-circuited, the glow relay 40 can be opened and the energization of the glow plug 50 can be interrupted to prevent the glow plug 50 from being damaged by overcurrent.

On the other hand, in the case of a short circuit between the elements, as shown in FIG. 4A, a short circuit occurs between the plurality of switch means 32 (MOS ₁ , MOS ₂ ), and one switch means 32 (MOS ₁ ). When the other switch means 32 (MOS ₂ ) is turned on even if the switch is turned off, the switch means 32 (MOS ₁ ) that is turned off is bypassed by bypassing the other switch means 32 (MOS ₂ ). Will be in the same state as
The operation by the primary determination means in step 100 to step 104 in the case where the short circuit between terminals corresponds to this figure (b) to (g), and the operation by the secondary determination means in step 105 to step 110 is as follows. This corresponds to FIGS. (H) to (k).
This Figure drive signals _{G 1} for driving one of the switching means 32 (MOS1) as shown in (b) is transmitted, the driving signal for driving the other switch means 32 (MOS2) as shown in the figure (c) When G ₂ is transmitted with a delay of a predetermined timing tg from the drive signal G ₁ , when an inter-element short circuit occurs as shown in FIG. MOS ₁ , MOS ₂ ) are applied with a drive voltage V _G so that their duty time t _d is increased by the timing gap t _g , and the output voltage V _SS as shown in FIGS. Is turned on and off at the apparent duty time (t _d + t _g ).
Therefore, as shown in the figure (e), the drive signals G ₁ within a predetermined time period from the fall of the drive signal G ₁ for driving the MOS ₁ is the output voltage V _SS by the output abnormality detecting section 32 at a timing of off detected, the output level becomes Hi, the primary determination signal C ₁₁ is output.
At this time, as shown in the figure (f), since the drive signal G ₂ is also before the rise of the drive signal G ₂ for driving the MOS ₂ is output is despite MOS ₂ off is detected, the primary judging signal _{C 12} is output.
When the primary determination signals C ₁₁ and C ₁₂ are transmitted each time the drive signals G ₁ and G ₂ are turned on and off and the abnormality detection count n is detected more than a threshold value (for example, 5 times), the primary determination output DI ₁ is output.

If it is determined by the primary determination that there is some abnormality rather than a false detection, the drive signal SI is stopped as shown in FIG. When the output voltage V _SS is detected within a predetermined period in this state, as shown in FIG. 5I, all the switch means 32 (MOS ₁ , MOS ₂ ) are stopped, and the energization is normally prevented. because there, the output level Lo is detected, as shown in the figure (j), it is determined to be short-circuited between the elements, that the output of the secondary determination signal DI ₂ is maintained at Lo, a short circuit between the elements Show.
If a second determination signal DI ₂ is not outputted, as shown in the figure (k), and cancels the stop of the drive signal SI, resumes transmission of the drive signal SI as shown in the figure (h) be able to.

With reference to FIG. 5, an example of a processing method after the secondary determination unit determines that an inter-element short-circuit is described.
When the inter-terminal short-circuit determination post-processing in step S120 is started, a plurality of switch means (for example, MOS ₁ and MOS ₂ ) in which the short-circuit between elements is detected in the inter-element short-circuit detection channel output stop means in step S121 are driven. One (G ₁ ) of the drive signals (G ₁ , G ₂ ) is stopped.
In the alternative energization count initialization means in step S122, a counter as an alternative output count counting means for counting the number of alternative outputs is initialized, and in the alternative energization processing means in the event of an element short circuit in step S123, an element short circuit has occurred. Among the drive signals (G ₁ , G ₂ ) for driving the plurality of switch means, the other switch means (MOS ₂ ) for which the drive signal (G ₂ ) is not stopped is used as an alternative energization means, Instead of the stopped switch means (MOS ₁ ), an alternative energization process for energizing the load is performed.
In the alternative energization processing frequency determination means in step S124, the alternative output frequency n for which the alternative energization processing in step S123 was performed is compared with a threshold value (for example, 5 times), and if it is less than the threshold value, the determination becomes Yes and the process proceeds to step S125.
The inter-element short-circuit elimination determination unit in step S126 determines whether there is an alternative output. If an alternative output is detected, the determination is No, and the process proceeds to step S127.
The alternative output number counting means in step S127 counts and adds to count the number n of the alternative energization processing, and returns to step S123.
If it is determined in step S124 that the number of alternative energization processes is equal to or greater than the threshold value, the determination is No and the process proceeds to step S125.
The tertiary determining means step S125, the tertiary determination signal DI ₃ indicating that it is an alternate energization process is outputted, the flow returns to step S123.
Until the short circuit between terminals is resolved and it is determined in step S125 that there is no alternative output. The alternative energization process of S123 is repeatedly performed.
If no alternative output is detected in step S125 and the determination is Yes, the process proceeds to step S128.
The inter-element short-dissolution decider postprocessing unit in step S128, the output is lost between element shunt according to an alternative energization is determined to have been eliminated at step S126, releases the output of the tertiary determination signal DI _3, the inter-device short Is detected and output of the drive signal (G ₁ ) to the switch means (MOS ₁ ) for which transmission of the drive signal (G ₁ ) has been stopped is resumed, and the normal return means of step S129 returns to the normal energized state. .

With reference to FIG. 6, the effect of the alternative energization process after the short circuit between elements in the present embodiment will be described.
If it is determined that the element is short-circuited, as described above, the drive signal SI that has been stopped during the secondary determination period is restored, and transmission of the drive signal SI is resumed as shown in FIG. .
According to the drive signal SI, as shown in FIGS. 2B and 2C, the transmission of the drive signals G ₁ and G ₂ is resumed. However, since the short circuit between the elements has occurred, the short circuit between the elements has occurred. switching means are _(MOS 1, MOS ₂₎ output potential _{V SS1, V SS2} respectively present views of (d), (f), the a state in which the duty time overlap with each other, the drive signal _(G 1, G ₂ ) When output is made despite being off, abnormality detection is counted as an output abnormality as shown in FIGS.
When the alternative energization process of the present embodiment is started, as shown in FIG. 5B, drive signals (G1, G ₂ ) for driving a plurality of switch means (MOS1, MOS ₂ ) in which an inter-element short circuit has occurred. One (G ₁ ) is stopped, and the switch means (MOS ₁ , MOS ₂ ) is opened / closed by the drive signal (G ₂ ) which is not stopped, so that the output potential V for driving each load _SS1 and _VSS2 do not overlap with the duty time as shown in FIGS.
Since the output on the side of the switch means (MOS ₁ ) that is alternatively energized while the drive signal (G ₁ ) is stopped is output even though the switch means is in the OFF state, this figure (e) As shown in (g), the number of times of abnormality detection is counted by the alternative energization frequency coefficient means, and the output of the switch means (MOS ₂ ) in which the drive signal (G ₂ ) is not stopped is normal as shown in FIG. The output is determined and the abnormal output is not counted.
When the alternative energization count n counted by the alternative energization count counting unit becomes equal to or greater than a threshold value (for example, 5), the tertiary determination output flag DI ₃₁ indicating that the alternative energization period is in effect, as shown in FIG.
At this time, the DI output output in accordance with the above-described steps S120 to S125 has information (D ₁ ) indicating that the switch means (MOS ₁ ) is abnormal as shown in FIG. Information (ERR ₂ ) indicating that this is due to alternative energization rises.
While the short circuit between the elements is occurring, an alternative energization process is performed. When the short circuit between the elements is resolved as shown in FIG. 5B, the alternative energization is performed as shown in FIG. was eliminated outputted from the side of the switch means (MOS _1), in step S128, the abnormality detection counter _{C 1} (alternate current number n) is cleared, the tertiary determination output flag _{DI 31} as shown in the figure (h) Canceled.
In step S128, the stopped drive signal (G1) is restarted, and the normal energization control is restored as shown in FIGS.
At this time, as shown in FIG. 6 (j), all the information bits indicating the normal state fall to the DI output.

With reference to FIG. 7, the effect of the alternative energization process after the short circuit between elements in the second embodiment of the present invention will be described.
In the above-described embodiment, the inter-terminal short-circuit elimination determination unit in step S126 is configured to immediately return to normal when it is determined that the inter-element short-circuit is eliminated when the output is not detected by the alternative energization process. The difference is that the number of times the output is no longer detected by the energization process is detected and the normal operation is restored.
When the post-terminal short-circuit determination post-processing in step S120a is started, the plurality of switch means (for example, MOS ₁ and MOS ₂ ) in which the short-circuit between elements is detected in the inter-element short-circuit detection channel output stop means in step S121a are driven. One (G ₁ ) of the drive signals (G ₁ , G ₂ ) is stopped.
In the inter-terminal short-circuit elimination determination variable initialization means in step S122a, a counter as an inter-terminal short-circuit elimination variable counting means for counting the variable m indicating the elimination of the short-circuit between terminals is initialized, and the alternative energization process at the time of inter-element short-circuit in step S123a Among the drive signals (G ₁ , G ₂ ) for driving the plurality of switch means in which the short circuit between the elements has occurred, the other switch means (MOS ₂ ) of the drive signal (G ₂ ) that is not stopped is used. As an alternative energization means, an alternative energization process for energizing the load instead of the switch means (MOS ₁ ) on the side where the drive signal is stopped is performed.
When the short circuit between the elements is eliminated, the channel in which the drive signal is stopped is not driven by the alternative energization process, and therefore no output is generated by the alternative energization process.
In the terminal short-circuit elimination determination means in step S124a, it is determined whether or not the terminal short-circuit has been eliminated based on the presence or absence of output due to alternative energization.
While the output from the channel stopped by the alternative energization process is detected, the process proceeds to No, and the alternative energization process at the time of short circuit between elements in step 123a is repeated.
If the output from the stopped channel is not detected in step S124a, the process proceeds to Yes, the inter-terminal short circuit elimination variable addition process in step 125a is performed, and the alternative process end determination unit in step S126a detects the alternative output in S125a. The terminal-to-terminal short-circuit elimination variable k that is no longer being compared is compared with a threshold value (for example, 5 times). If the variable is less than the threshold value, the determination is No, and the alternate energization process at the time of the element short-circuit in step S123a is repeated.
When the inter-terminal short-circuit elimination variable k is greater than or equal to the threshold value in step 126a, it is determined that the inter-element short-circuit has been eliminated, and the process proceeds to Yes, and the inter-element short-circuit elimination determination post-processing in step 127a is performed.
If it is determined in step S124a that the output due to alternative energization has disappeared and the short circuit between elements has been eliminated, the short circuit between elements is detected and the drive signal (G ₁ ) is transmitted. There the output of the switch means has been stopped driving signal to the (MOS ₁₎ (G ₁₎ is restarted, returning to the normal conducting state by normal return means of the step S128a.

With reference to FIG. 8, the short circuit abnormality processing method in the 3rd Embodiment of this invention is demonstrated. In the above-described embodiment, after determining whether an internal short circuit or an inter-element short circuit is determined by secondary determination, the processing when it is determined as an inter-element short circuit has been described. Is determined, the short circuit abnormality process is immediately started before the secondary determination. According to the present embodiment, processing when a short-circuit abnormality occurs is quickly performed, and damage to the glow plug can be reliably prevented.
First, when any short-circuit abnormality is detected by the above-described primary determination means (S100 to S104), the post-primary determination processing in step S120b is started.
When the primary determination post-processing in step S120b is started, the drive signal (G ₁ ) for driving the switch means (for example, MOS ₁ ) in which the short-circuit abnormality is detected in the short-circuit abnormality detection channel output stop means in step S121b is stopped. The
In the alternative energization count initialization means in step S122b, a counter as an alternative output count counting means for counting the number of alternative outputs is initialized, and in the alternative energization processing means in step S123b, switch means (MOS ₁₎ in which a short circuit abnormality is detected. ) To the load instead of the switch means (MOS ₁ ) on the side where the drive signal is stopped, using another switch means (for example, MOS ₂ ) instead of the drive signal (G ₁ ) for driving the drive signal). An alternative energization process is performed to energize.
In the alternative energization processing frequency determination means in step S124b, the alternative output frequency n for which the alternative energization processing in step S123b was performed is compared with a threshold value (for example, 5 times), and if it is less than the threshold value, the determination becomes Yes, and the process proceeds to step S125.
In the alternative output determination means in step S125b, the presence / absence of an alternative output is determined. If an alternative output is detected, the determination is Yes, the process proceeds to step S126b, and if the alternative output is not detected, the determination is No, and the process proceeds to step S127b. .
When the alternative energization processing energization count n is equal to or less than the threshold value and no alternative output is detected by the alternative energization, the short circuit abnormality detected by the primary determination means (S100 to S104) is not an inter-element short circuit but an intra-element short circuit. It is conceivable that in-element short-circuit determination is performed in step 127b, and in-element short-circuit processing is performed in step S110 described above. In this embodiment, since the output of the channel in which the abnormality is detected in the primary determination is stopped, the output stop is maintained as it is when the intra-element short-circuit determination of S127b is made.
If an alternative energization output is detected in step S125b, the alternative output frequency counting means in step S126b counts up to count the number n of alternative energization processes, and the process returns to step S123b.
If it is determined in step S124b that the alternative energization processing count n is greater than the threshold, the determination is No, and the process proceeds to step S128b.
The tertiary determination signal output means in step S128b, it is outputted tertiary determination signal DI ₃ indicating that it is an alternate energization process.
Further, the inter-terminal short-circuit elimination determination means in step S129b eliminates the alternative output when the inter-terminal short-circuit is eliminated. Therefore, while the alternative output is detected, the determination is No and the process returns to step S123b to repeat the alternative energization process. .
If the inter-terminal short circuit is eliminated and the alternative output is not detected in step S129b, and the determination is Yes, the process proceeds to step S130b.
The inter-element short-dissolution decider postprocessing unit in step S130b, when the alternative current output is eliminated element between short circuit due is determined to have been eliminated at step S129b, cancels the output of the tertiary determination signal DI _3, short circuit abnormality The output of the drive signal (G ₁ ) to the switch means (MOS ₁ ) that has been detected and the transmission of the drive signal (G ₁ ) has been stopped is resumed, and the normal energization state is restored by the normal return means in step S131b.

Here, referring to FIGS. 9, 10, and 11, assuming that the conventional abnormality determination flow as shown in FIG. 9 is applied to the abnormality diagnosis apparatus of the present invention, the abnormality used in the conventional energization control apparatus is used. The problem of the diagnostic device will be described in detail.
In the conventional abnormality determination flow in which the short circuit abnormality cannot be distinguished from the short circuit between the elements and the short circuit between the elements, as shown in FIG. 9, the element open output detection means in step 200 drives according to the drive signal SI from the ECU 20. When the switch means 31 that is driven to open and close by the control means (DCU) 32 is opened, the output potential detection means provided as the output abnormality detection means 33 is in the open state (off state). Detect the presence or absence of output.

Next, when the battery voltage V _DD is detected at the output side of the switching element 31 in step 200, the output determination means at the element open time in step 201 sets the output level even though the switch means 31 is in the OFF state. Since it becomes Hi, it is determined in step 202 that there is a short circuit abnormality, and in step 203, the power supply to the load is cut off.
If the battery voltage V _DD is not detected on the output side of the switching element 31 in step 200, the output level of step 201 is Lo, it is determined that there is no abnormality, the process returns to step 200, and the determination is repeated.

Even with the conventional abnormality diagnosis device, the element as shown in FIG. 10A is transmitted in the state where the drive signal SI that is turned on / off with the pulse having the duty time t _d and the period T as shown in FIG. When an internal short circuit occurs, the output voltage _VSS is always Hi as shown in FIG. 10C, and the abnormality detection signal DI is transmitted as shown in FIG. It is possible to actuate the energization stop latch to cut off the energization to the load and protect the switch means and the load as shown in FIG.

However, in the conventional abnormality diagnosis apparatus, one switch means 31 (MOS ₁ ) is driven by the drive signal G ₁ shown in FIG. 11B, and the other switch means 31 (MOS ₂ ) is shown in FIG. When an inter-element short circuit occurs between a plurality of switch means 31 (MOS ₁ , MOS ₂ ) as shown in FIG. 5A in a state driven by the drive signal G ₂ shown, one switch means 32. Even when (MOS ₁ ) is off, the other switch means 32 (MOS ₂ ) is bypassed and becomes conductive.
Therefore, the output voltage V _SS of _one switch means 32 (MOS ₁ ) is driven with an apparent duty time (t _d + t _g ) as shown in FIG. signal G ₁ is the detection output is in the off state, the figure (e) an abnormality detection signal DI as shown in it is transmitted, to cut off the power supply to the load by operating the energization stop latch.
Therefore, even if it is in a recoverable state, such as a short circuit between elements, it cannot be distinguished from a short circuit within the element, and the current supply to the load is uniformly interrupted.
Also, when noise is likely to occur, such as during cranking, the energization stop latch is activated and the load is de-energized even if the abnormality detection signal DI is erroneously transmitted due to the influence of noise. There is also a fear.

It should be noted that the present invention is not limited to the above embodiment, and when an output abnormality occurs in which the output is detected even though the semiconductor element is off, all of the plurality of switch means are temporarily set. By detecting the presence or absence of output in the stopped state, it is possible to identify whether the detected output abnormality is due to an internal short circuit or an inter-element short circuit, and to enable more accurate energization control. Changes can be made as appropriate without departing from the spirit of the invention.
For example, in the above embodiment, as the output abnormality detection means, an example in which the output potential detection means for detecting the presence or absence of conduction of the element by detecting the potential on the output side of the element is shown, but as the output abnormality detection means, A configuration may be added in which a shunt resistor is provided to detect an overcurrent, or a disconnection is detected by measuring an output current with a current sensor in a state where the switch means is closed, as is conventionally done. .

DESCRIPTION OF SYMBOLS 1 Energization control apparatus 10 Power supply 11 Key switch 20 Electronic control apparatus (ECU)
30 Energization control unit (GCU)
31 Switch means (MOS ₁ , MOS ₂ , MOS ₃ , MOS ₄ )
32 Drive control means (DCU)
33 Output abnormality detection means (output potential detection means)
34 Abnormality diagnosis device (DIU)
40 Power cut off means (relay)
50 load (glow plug)
SI, G ₁ , G ₂ , G ₃ , G ₄ Drive signal DI ₁ Primary determination signal DI ₂ Secondary determination signals S100 to S103 Primary determination means S100 Element open output detection means S101 Element open output determination means S102 Abnormal count counting Means S103 False detection judgment means S105 to S110 Secondary judgment means S105 Drive signal stop means S106 Element drive stop time output detection means S107 Element drive stop time output judgment means S108 Intra-element short-circuit judgment S109 Inter-element short-circuit judgment
S120 to S129 Alternative energization means S120 Inter-terminal short-circuit determination post-processing S121 Inter-element short-circuit detection channel output stop means S122 Alternative energization frequency initialization means S123 Inter-element short-circuit alternative energization processing means S124 Alternative energization processing frequency determination means S125 Tertiary determination means S126 Inter-element short-circuit elimination determination means S127 Alternate output count counting means S128 Inter-element short-circuit elimination determination post-processing means S129 Normal recovery means

JP 2008-31979 A

Claims (7)

Provided for each load with respect to a power supply and a plurality of loads, and switch means for controlling supply and stop of power from the power supply to the load by opening and closing, and a drive signal for controlling opening and closing of the switch means In an abnormality diagnosis device for detecting and diagnosing an abnormality in an energization control device for controlling energization to the load, comprising drive signal transmission means and drive control means for opening and closing the switch means according to the drive signal,
An output abnormality detecting means for detecting an output abnormality of each switch means is provided for each of the plurality of switch means,
Primary determination means for determining, by the output abnormality detection means, whether or not there is an output abnormality of the switch means when one of the plurality of switch means is opened according to the drive signal;
After determining that the output is abnormal by the primary determination means, the drive signal of the switch means in which the abnormality has occurred is stopped, and the switch means in which the drive signal is stopped is opened and closed by the drive signal that opens and closes the other switch means. And an alternative energization means that attempts to energize a plurality of loads. The primary determination means includes an element open output detection means for detecting an output when the switch means is in an open state, an element open output determination means for determining a detection result of the element open output detection means, An error detection unit that counts the number of abnormalities detected by the output determination unit when the element is open, and an error detection that determines whether the error is detected by comparing the number of abnormalities counted by the error number counting unit with a threshold value The abnormality diagnosis device according to claim 1, further comprising a determination unit . When the primary determination means determines that the output is abnormal, the drive signal is stopped, all of the plurality of switch means are temporarily opened, and the switch means in which the output abnormality is detected by the primary determination means The abnormality diagnosis apparatus according to claim 1, further comprising secondary determination means for determining again whether or not there is an output abnormality by the output abnormality detection means . The secondary determination means is a drive signal stop means for stopping the drive signal;
An element drive stop output detection means for detecting the output of the switch means in a state where the drive signal is stopped by the drive signal stop means;
An element driving stop output judging means for judging the detection result of the element driving stop output detecting means,
If it is determined that the output is abnormal by the primary determination means, and if it is determined that the output is abnormal by the drive stop time output determination means, it is determined that the element is short-circuited,
The abnormality diagnosis device according to claim 3 , wherein when the primary determination unit determines that the output is abnormal and when the drive stop time output determination unit determines that there is no output, the abnormality diagnosis device according to claim 3 . The abnormality diagnosis device according to claim 3 or 4, wherein the alternative energization process by the alternative energization means is performed after the primary determination and before the secondary determination or after the secondary determination. The alternative energization processing is performed by comparing the alternative output number counting means for counting the number of alternative outputs output in a state where the drive signal is stopped by the alternative energization means, and the alternative output number counted by the alternative output number counting means and a threshold value. Tertiary determination means for determining whether or not
When an alternative output is not detected during the alternative energization process, an inter-element short-circuit elimination determination unit that determines that the inter-element short circuit has been eliminated,
If it is determined that the short circuit has been eliminated between the elements by the element between short dissolution decider means, according to claim 3 to 5 and a normal return means for returning to the normal energization control cancels the stop of the driving signal The abnormality diagnosis device according to any one of claims.   The abnormality diagnosis apparatus according to claim 1, wherein the load is a glow plug that is provided for each cylinder of the diesel engine and that heats the air-fuel mixture and assists ignition.

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