JP2010112257A - Device and method for detecting switch failure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch failure detection device and method of good responsiveness without making an erroneous decision within a short decision time. <P>SOLUTION: The switch failure detection device for detecting a failure in at least two contacts which go ON/OFF in mutually interlocking relation includes a decision means (10) for deciding an all-ON state of the two contacts and a control means (10) for instructing the starting of required control according to the result of the decision by the decision means, wherein the decision means confirms that a non-faulty one out of the two contacts actually goes ON/OFF in response to a user operation before fixing the decision result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a switch failure detection apparatus and method, and more particularly to a switch failure detection apparatus and method having a plurality of (at least two) contacts.

  2. Description of the Related Art Recently, in vehicles such as automobiles (hereinafter simply referred to as “vehicles”), an engine starter that can start and stop an engine without inserting a mechanical key into the keyhole has been frequently used. I came. In this engine starting device, the portable device owned by the driver and the vehicle-mounted device collate specific information (hereinafter referred to as an ID code) assigned to the vehicle, and if the code matches, the driving is performed. The engine is allowed to start and stop based on the operation of the engine start switch by a person.

  The engine start switch used in such a device has a much higher degree of design freedom than a keyhole-use switch. Therefore, in general, the one-touch type in which the operability is emphasized, that is, a pressing operation is performed with a fingertip. This is a “push switch”. Hereinafter, a switch using this method is referred to as a “push-type engine start switch”.

  By the way, in the case of a switch having an electrical contact in general, rarely “ON failure” due to fusion between contacts (failure that does not return to OFF while being ON) or “OFF failure” due to disconnection of a signal line ( Failure that does not turn ON even when operated) may occur. Since such a failure is particularly fatal in a push-type engine start switch for a vehicle that requires a high level of safety, an effective countermeasure technique is required.

  Therefore, in order to be able to start and stop the engine safely even when the “ON failure” or “OFF failure” occurs, for example, it is described in Patent Document 1 below. As described above, a push type engine start switch is provided with a plurality of contacts, and when one of the contacts fails, the switch is turned on or off based on the output signal of the other contact. Technology is known.

  More specifically, in Patent Document 1 below, each switch signal of a plurality of contacts is subjected to a logical sum determination (OR determination) to allow engine start, and each switch signal of the plurality of contacts is subjected to a logical product determination ( AND determination) and allowing the engine to stop. Further, this document also describes that a failure is determined when a mismatched state of switch signals of a plurality of contacts has elapsed for a certain period of time, and an input (switch signal) that is recognized as a failure is excluded from the determination.

JP-A-2005-140015

  However, in the above-described prior art, a failure is determined when a mismatch occurs in the state of a plurality of contacts and the state continues for a predetermined time or more. There is a problem that it is not possible to correctly determine which contact point has failed.

  Accordingly, an object of the present invention is to provide a switch failure detection apparatus and method with reduced erroneous determination.

The switch failure detection device according to the present invention is a switch failure detection device that detects a failure of at least two contacts that are turned ON / OFF in conjunction with each other, a determination unit that determines all ON states of the two contacts, and the determination unit Control means for instructing the start of the required control according to the determination result, and the determination means actually turns ON / OFF the non-failed contact of the two contacts in response to a user operation. After confirming this, the determination result is fixed.
The switch failure detection method according to the present invention is a switch failure detection method for detecting a failure of at least two contacts that are turned ON / OFF in conjunction with each other, a determination step that determines all ON states of the two contacts, and the determination step And a control step for instructing the start of the required control according to the determination result, wherein the non-failed contact of the two contacts is actually turned on / off in response to a user operation. After confirming this, the determination result is fixed.

  According to the present invention, since the failure is determined based on the re-operation by the user, it is possible to provide a switch failure detection device and method that reduce the occurrence of erroneous determination.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a vehicle engine start / stop device.
The vehicle engine start / stop device includes an in-vehicle device 1 and a vehicle key 2. The vehicle key 2 takes the form of a portable device carried by a driver, and stores an ID code for key verification in the portable device. ing.

  The in-vehicle device 1 includes a start / stop switch (corresponding to a push-type engine start switch) 3, an ACC relay 4, an IG relay 5, a brake switch 6, an engine ECU 7, a power supply switching ECU 8 connected thereto, and a notification unit 9. First, the configuration of the start / stop switch 3 will be described.

FIG. 2 is a configuration diagram of the start / stop switch 3.
The start / stop switch 3 is a push switch of a plurality of contacts (at least two contacts) type, and here, two movable contacts 3a and 3b which are turned ON / OFF in conjunction with each other, and a pair of these movable contacts 3a and 3b. Fixed contacts 3c to 3f, an elastic member 3g such as a spring for keeping the movable contacts 3a and 3b in an OFF state, and a push button 3h for receiving an operation input against the elastic force of the elastic member 3g. Yes.

  The start / stop switch 3 having such a configuration is normally in an OFF state because the two movable contacts 3a and 3b and the fixed contacts 3c to 3f are separated from each other by the elastic force of the elastic member 3g as shown in the figure. However, when an operating force larger than the elastic force of the elastic member 3g is applied to the push button 3h, the two movable contacts 3a and 3b and the fixed contacts 3c to 3f come into contact with each other and are in the ON state. Thus, the switch signals SW1 and SW2 extracted from the fixed contacts 3d and 3f on the right side in the figure are changed (transitioned) to a predetermined potential (a power supply potential Vb corresponding to the H level in the illustrated example).

  Next, returning to FIG. 1, the code reading device 4 a reads the ID code stored in the vehicle key 2 and transmits it to the power supply switching ECU 8. The power supply switching ECU 8 compares this ID code (ID code read from the vehicle key 2) with the ID code stored in the ROM, and if they match, an engine start permission signal is sent to the engine ECU 7. Send.

  The power supply switching ECU 8 is a control unit of a program control system composed of a well-known CPU, ROM, and RAM. The power supply switching ECU 8 is operated whenever the start / stop switch 3 is pressed. And a predetermined notification sound is output from the notification unit 9 to the driver whenever necessary.

  Further, switch signals SW1 and SW2 from the start / stop switch 3 are inputted to the input terminal of the power supply switching ECU 8, and the power supply switching ECU 8 has the potentials of these switch signals SW1 and SW2 equal to or higher than a predetermined value (or below). ), And if it is determined to be equal to or greater than a predetermined value, it is determined that the start / stop switch 3 is being pressed.

  Further, when the start / stop switch 3 is pressed while the brake pedal is being depressed in the engine “start” standby state, the power supply switching ECU 8 receives an ID code (vehicle key 2) from the code reading device 4a. ID code read out from the vehicle), and the collation result between the ID code (ID code read out from the vehicle key 2) and the ID code stored in the ROM is a collation result. In this case, an engine start signal for starting the engine is output to the engine ECU 7.

  Further, the power supply switching ECU 8 outputs an engine stop signal for stopping the engine to the IG relay 5 when the start / stop switch 3 is pressed while the engine is running.

  In the operating state, the ACC relay 4 connects the accessory circuit of the vehicle to the positive power supply terminal of the in-vehicle battery, and puts the accessory circuit in an energized state. The IG relay 5 connects a starter motor or the like for starting the vehicle engine in an operating state in addition to the accessory circuit in response to an engine start signal from the power supply switching ECU 8 to the plus power supply terminal, and energizes the starter motor or the like. . Further, when the IG relay 5 obtains the engine stop signal from the power supply switching ECU 8, the IG relay 5 is brought into a non-connected state, and the starter motor or the like and the plus power terminal of the in-vehicle battery are brought into a non-energized state.

  The brake switch 6 is a switch that is turned on when the brake pedal is depressed, and inputs a detection signal thereof to the power supply switching ECU 8.

  The engine ECU 7 is a control unit of a program control system including a well-known CPU, ROM, and RAM. When the engine ECU 7 acquires an engine start permission signal from the power supply switching ECU 8, the engine ECU 7 can start the engine. Set to the engine start standby state. Further, the engine ECU 7 starts operations of the starter motor, the fuel injection device, and the ignition device based on the engine start signal from the power supply switching ECU 8. Thus, the engine is started by the fuel being injected into the engine while the starter motor is rotating and the spark plug is ignited.

  FIG. 3 is a diagram showing a switch failure determination program executed by the power supply switching ECU 8. In this program, first, it is determined whether or not the switch signal SW1 is ON (step S1). If it is not ON, it waits as it is until it is ON, and if it is ON, it is next determined whether or not the switch signal SW2 is ON (step S2). If the switch signal SW2 is ON, it is determined that the start / stop switch 3 is being pressed (that is, the ON state) (step S3), and the flow ends, but the switch signal SW2 is ON. If not, failure determination is started (step S4), and it is again determined whether or not the switch signal SW1 is ON (step S5). If the switch signal SW1 is ON, it is determined whether or not the switch signal SW2 is ON (step S6). If the switch signal SW2 is not ON, the process returns to step S5, while the switch signal SW2 is ON. If there is, the failure determination is continued (step S7), the notification unit 9 is driven (step S8), and it is determined again whether or not the switch signal SW1 is ON (step S9).

  If the switch signal SW1 is not ON, the failure determination is finished (step S12) and the flow is completed. If the switch signal SW1 is ON, it is determined whether the switch signal SW2 is ON (step S10) If the switch signal SW2 is ON, the process returns to step S9. On the other hand, if the switch signal SW2 is not ON, an ON failure of the start / stop switch 3 is determined (step S11), and the flow ends.

  On the other hand, if the determination result in step S5 is NO, that is, if the switch signal SW1 is not ON, it is determined whether or not the switch signal SW2 is ON (step S13). If the switch signal SW2 is ON, If the failure determination is finished (step S19) and the flow is completed and the switch signal SW2 is not ON, the failure determination is continued (step S14), the notification unit 9 is driven (step S15), and the switch signal SW1 is again set. It is determined whether or not it is ON (step S16). If the switch signal SW1 is not ON, the process returns to step S13. If the switch signal SW1 is ON, it is determined whether or not the switch signal SW2 is ON (step S17), and the switch signal SW2 is ON. If there is, the failure determination is finished (step S19), the flow is completed, and if the switch signal SW2 is not ON, an OFF failure of the start / stop switch 3 is determined (step S18), and the flow is finished.

Next, a specific example of the failure determination process (see step S4, step S7, and step S14 in FIG. 3) will be described.
First, as described above, the start / stop switch 3 in the present embodiment is a normally OFF type in which the normal state is OFF and the operation is ON, and the number of contacts is “2”. It becomes four.

<Both ON failure>
Both ON failures refer to failures that do not return to OFF while the two movable contacts 3a and 3b are fixed together. When this failure occurs, the function of the start / stop switch 3 is completely lost. It is not self-propelled and is in a complete failure state. It is necessary to carry it in the factory with a tow truck for repair.
<Single ON failure>
The one-side ON failure is a failure that does not return to OFF while one of the two movable contacts 3a and 3b is fixed. Since the other of the two movable contacts 3a and 3b is operating normally, it is in a semi-failed state, and the engine can be started and stopped using the contact on the normal side. Although it is self-propelled, there is a possibility that the contact on the normal side will eventually fail, so it is necessary to receive repairs as soon as possible.
<Both OFF failure>
Both OFF failures are failures in which the two movable contacts 3a and 3b are not turned ON due to disconnection or the like. The function of the start / stop switch 3 is completely lost. It is not self-propelled and is in a complete failure state. It is necessary to carry it in the factory with a tow truck for repair.
<Single OFF failure>
The single OFF failure refers to a failure in which one of the two movable contacts 3a and 3b does not turn ON. Since the other of the two movable contacts 3a and 3b is operating normally, it is in a semi-failed state, and the engine can be started and stopped using the contact on the normal side. Although it is self-propelled, there is a possibility that the contact on the normal side will eventually fail, so it is necessary to receive repairs as soon as possible.

Of these four failure categories, the single ON failure and single OFF failure can be further divided into the following two patterns.
<First pattern>
This is a pattern in which a single ON failure or a single OFF failure has occurred “before” when the push operation is performed, that is, a pattern in which a trouble such as contact sticking or disconnection has occurred in advance.
<Second pattern>
This is a pattern in which a single ON failure or a single OFF failure occurs “in the middle” of the push operation, that is, a pattern in which trouble such as contact sticking or disconnection occurs temporarily during the push operation.

  Hereinafter, the determination operation for each failure category and pattern will be described. In the following description, “both OFF failure” is not referred to. This is because when both OFF failures occur, there is no reaction even if the start / stop switch 3 is operated, and the failure is immediately noticed. Moreover, in the case of both OFF failures, the engine cannot be started, so there is no inconvenience directly related to safety.

First, the following four time parameters (T0 to T4) necessary for failure determination are set first.
"T0 (ON deviation allowable time)"
This is a time that takes into account the operational deviation between the two contacts 3a and 3b. The failure determination is started after the time T0 has elapsed from the time when the switch signals SW1 and SW2 change. This time T0 is preferably as short as possible. However, since it actually depends on the mechanical variation of the start / stop switch 3 and the pressing speed of the push button 3h, it can be set appropriately by trial and error in consideration of these. Good. For example, assuming that the mechanical variation (such as attachment error of the two contacts 3a and 3b) is 1.5 mm at the maximum, T0 = 25 ms + α when the operation speed is 60 mm / s, and when the operation speed is 10 mm / s. T0 = 150 ms + α. When the operation speed is 50 mm / s, T0 = 300 ms + α. α is a predetermined margin. Since the general operation speed is about 60 mm / s, there is no major inconvenience even when T0 = 25 ms + α. However, to make sure, the minimum operation speed T0 = 300 ms + α is adopted, and further, α = 200, and T0 = 500 ms.
“T1 (first failure determination duration)”
This is the time for the first determination used to eliminate instantaneous changes in the switch signals SW1 and SW2 due to noise or the like, for example, T1 = 100 ms. When the change of the switch signals SW1 and SW2 continues beyond this time T1, the change is determined to be true, and otherwise, it is excluded as a false change due to noise or the like.
“T2 (second failure determination duration)”
The same as T1 described above. However, it is different in that it is the time for the second determination.
“T3 (OFF deviation judgment time)”
This is the OFF deviation determination time that takes into account the operational deviation of the two contacts 3a and 3b. This time T3 is determined by the spring force of the elastic member 3g, and is always constant unless the deterioration of the elastic member 3g is taken into consideration. Here, T3 = 100 ms.

(1) Judgment operation of both ON faults When the two switch signals SW1 and SW2 are both in the ON state for a long time, it is judged as “both ON fault” of the start / stop switch 3. “Long time” refers to a time period during which the two switch signals SW1 and SW2 cannot be in an ON state in a normal use situation, for example, a time period from several tens of seconds to several tens of minutes. is there.

(2) Single ON Failure / First Pattern Determination Operation Next, the single ON failure / first pattern determination operation will be described with reference to the drawings.
FIG. 4 is a diagram showing a time chart of one-side failure / first pattern. This figure assumes a case where a fixed contact and a movable contact of one switch signal SW1 are fixed and an ON failure occurs. The power supply switching ECU 8 periodically determines the states of SW1 and SW2. The failure determination is started when the mismatch between SW1 is in the ON state and SW2 is in the OFF state continues for a time t0 after the lapse of T0 from the rising edge of the switch signal SW1. Thus, even if a mismatch occurs for a predetermined time or longer, no conclusion for failure determination is given. This is because it is not yet possible to determine whether an ON failure has occurred on the SW1 side or an OFF failure has occurred on the SW2 side with the start / stop switch 3 being pressed. The failure determination is continued as if something abnormal has occurred. Furthermore, it is determined that the switch signal SW1 is in the ON state and the SW2 is in the OFF state at time t1 when T1 has elapsed. Even at this time t1, since the mismatch has occurred, the failure determination is simply continued. No conclusions yet. Thereafter, in response to the pressing operation of the start / stop switch 3 by the driver, the other switch signal SW2 rises, and the state of each SW is determined at a time t3 after T2 has elapsed from the rising time t2. In this example, the determination result is that SW1 is in the ON state and SW2 is in the ON state. Further, the notification unit 9 requests the driver that an abnormality has occurred and performs a pressing operation again. Then, when the switch signal SW2 falls in response to the pressing release operation by the driver, the state of each SW is determined at time t5 after T3 has elapsed from time t4 of the fall. In this example, it is determined that SW1 is in the ON state and SW2 is in the OFF state. In this way, first, the mismatch of each SW is determined, then the match of each SW is determined, and the result of the failure determination is obtained when the mismatch of each SW is determined again. In the case of this example, it is determined as a one-on failure (first pattern). Further, in response to the notification from the notification unit 9, the driver performs the pressing operation of the start / stop switch 3 again, and at the time t6 when the other switch signal SW2 rises in response, the state of each SW is determined. . In this example, since both SW1 and SW2 are in the ON state, the start / stop switch 3 is determined to be on.

In other words, if SW1 is changed to the OFF state at this time, it is not determined that the start / stop switch 3 is ON.
That is,
a) When any one of the switch signals changes from OFF to ON, and the mismatch due to the continued continuation of the other switch signal continues for 500 ms (T0) or longer, the failure determination starts.
b) If it is determined that the mismatch of the SW state continues for 100 ms (T1) after a), the failure determination is continued.
c) When the switch signal that was OFF in b) changes from OFF to ON and the other switch signals remain ON for 100 ms (T2) or longer, the failure determination is continued.
d) When the switch signal turned on in c) changes from ON to OFF and the other switch signals are in the ON state of 100 ms (T3) or more, a conclusion of failure determination is given.
As described above, when the mismatch of the state of each SW occurs, the conclusion of the failure determination is not made. Thereafter, when the start / stop switch 3 is pushed by the driver and the normal SW state is reversed and the state of each SW is matched, and then the state of each SW is again unmatched, it is determined that there is a failure. To do. Furthermore, “ON” of the start / stop switch 3 can be determined at the time of the second pressing operation.

(3) Single ON Failure / Second Pattern Determination Operation FIG. 5 is a diagram illustrating a time chart of the single ON failure / second pattern. This figure assumes a case where an ON failure has occurred at the contact (movable contact 3a) of one switch signal SW1. in this case,
a) When one of the switch signals (SW2 in this case) is turned ON → OFF and the other switch signal (SW1 in this case) is ON, the failure determination is started.
b) If it is determined that the mismatch of the state of each SW continues for 100 ms (T1) after a), the failure determination is continued.
c) If the switch signal (SW2 in this case) turned OFF in a) changes from OFF to ON and the other switch signals are ON for 100 ms (T2) or longer, the failure determination is continued.
d) When the switch signal (SW2 in this case) turned on in c) changes from ON to OFF and the other switch signals are in the ON state, a conclusion of failure determination is made and the switch signal = OFF is determined.
Thus, by pressing the start / stop switch 3 twice by the driver, “failure” can be determined after T3 from the release of the second pressing operation, and the start / stop switch 3 is set to “OFF”. Can be confirmed.

(4) Single OFF Failure / First Pattern Judgment Operation FIG. 6 is a time chart of single OFF failure / first pattern. This figure assumes that an OFF failure has occurred at the contact point (movable contact point 3b) of one switch signal SW2. in this case,
a) From the confirmation of OFF of both switch signals, it is determined that the normal push switch signal is OFF,
b) When one of the switch signals is changed from OFF to ON and the other switch signal is in the OFF state for 500 ms (T0) or longer, the failure determination is started.
c) After b), if it is determined that the mismatch of the state of each SW continues for 100 ms (T1) or more, the failure determination is continued.
d) When it is determined that the switch signal that was ON in c) changes from ON to OFF and the OFF state of the other switch signals continues for 100 ms (T2) or longer, the failure determination is continued.
e) When it is determined that the switch signal turned OFF in d) changes from OFF to ON and the OFF state of other switch signals continues for 500 ms (T0) or longer, the failure is confirmed and the switch signal = ON. Determine.
In this way, by pressing the start / stop switch 3 twice by the driver, it is possible to determine “failure” during the second pressing operation and to confirm that the start / stop switch 3 is “ON”. can do.

(5) Single OFF Failure / Second Pattern Determination Operation FIG. 7 is a diagram showing a time chart of single OFF failure / second pattern. This figure assumes that an OFF failure has occurred at the contact point (movable contact point 3b) of one switch signal SW2. in this case,
a) When both switch signals are in the OFF state, it is determined that the push switch signal is OFF,
b) When any one of the switch signals is changed from OFF to ON and it is determined that the OFF state of the other switch signal continues for 500 ms (T0) or longer, the failure determination is started.
c) After b), when it is determined that the mismatch of the state of each SW continues for 100 ms (T1) or longer, the failure determination is continued.
d) When it is determined that the switch signal that was ON in c) changes from ON to OFF and the OFF state of other switch signals continues for 100 ms (T2) or longer, the failure determination is continued, and the notification unit 9 notifies the driver that an abnormality has occurred and requests that the switch be pressed.
e) It was determined that the switch signal turned OFF in d) changed from OFF to ON in response to the driver's second switch pressing operation, and the OFF state of the other switch signals continued for 500 ms (T0) or longer. In this case, the failure is confirmed and the switch signal = ON is confirmed.
In this way, by pressing the start / stop switch 3 twice by the driver, it is possible to determine “failure” during the second pressing operation and to confirm that the start / stop switch 3 is “ON”. can do.

  As described above, in this embodiment, in order to avoid erroneous switch ON determination, the start / stop switch 3 is determined to be “ON” in all ON state determination (AND determination) of a plurality of contacts, and control such as engine start is performed. At the same time, the failure determination of the switch is performed after confirming that the non-failing contact is turned ON / OFF by the user operation, that is, based on the user operation. Therefore, since the failure determination is performed, a specific effect that the time until the failure is determined can be shortened. Furthermore, it is possible to more accurately determine an ON failure and an OFF failure.

  Specifically, when the push switch is determined to be pressed, it is not determined that the push switch is turned on for the first time, and only a warning (first notification) that prompts re-operation is notified to the user (control such as engine start is started). No), the actual failure determination and failure determination are performed at the second press operation, and it is determined that the push switch is ON according to the input of the normal contact and control is started.

  Further, at the time of push switch release determination, the failure determination → the failure is determined by re-pressing + release operation (second release operation), and the push switch OFF may be determined by normal contact input.

  The failure recovery can be determined by detecting the failure recovery when both OFFs are detected after the one-on failure detection, and after the one-off failure detection, the failure recovery is determined when both the ONs are detected. What is necessary is just to judge.

It is a block diagram of the engine start-stop device for vehicles. 3 is a configuration diagram of a start / stop switch 3. FIG. It is a figure which shows the switch failure determination program performed with power supply switching ECU8. It is a figure which shows the time chart of a piece ON failure / 1st pattern. It is a figure which shows the time chart of half ON failure / 2nd pattern. It is a figure which shows the time chart of a piece OFF failure / 1st pattern. It is a figure which shows the time chart of a piece OFF failure / 2nd pattern.

Explanation of symbols

3a contact 3b contact 10 power supply switching ECU (determination means, control means)

Claims (2)

In a switch failure detection device that detects a failure of at least two contacts that are turned ON / OFF in conjunction with each other,
Determining means for determining all ON states of the two contacts;
Control means for instructing the start of the required control according to the determination result of the determination means,
The determination means includes
A switch failure detection apparatus, wherein the determination result is confirmed after confirming that the contact that is not out of the two contacts is actually turned ON / OFF in response to a user operation. In a switch failure detection method for detecting a failure of at least two contacts that are turned ON / OFF in conjunction with each other,
A determination step of determining all ON states of the two contacts;
A control step for instructing the start of the required control according to the determination result of the determination step,
The determination step includes
A switch failure detection method comprising: confirming that a contact that is not out of the two contacts is actually turned ON / OFF in response to a user operation, and then determining the determination result.

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