JP2003182557A - Device and method for failure diagnosis of vehicular switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure diagnosis device of a vehicular switch capable of reducing the possibility of erroneous diagnosis caused by a use condition and obtaining high reliability. <P>SOLUTION: A main switch Sw2 detects whether a brake pedal 1 is stepped on and reaches a first predetermined position or not, and an auxiliary switch Sw1 detects whether the brake pedal 1 reaches a second predetermined position between an initial position and the first predetermined position or not. When it is detected that the brake pedal 1 reaches the second predetermined position, an ECM 7 starts the integration of time. When the integrated value of time reaches a first predetermined value and it is detected that the brake pedal 1 reaches the first predetermined position or that the brake pedal 1 does not reach the second predetermined position, the ECM 7 stops the integration of time, clears the integrated value, and integrates the number times that the integrated value of time reaches the first predetermined value to discriminate that the main switch Sw2 causes a failure when the integrated value of the number reaches a second predetermined value. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosing apparatus and a failure diagnosing method for judging a failure of a vehicle switch such as a brake pedal switch.

[0002]

2. Description of the Related Art In a general vehicle, when a brake pedal is depressed, a brake pedal switch detects the depression, and a brake lamp is lit in response to the detection information to decelerate the driver of the following vehicle. Notify visually.
In recent years, the information from the brake pedal switch is
It is also widely used for controlling engines, ATs and ABSs. In such a case, if the brake pedal switch fails, there is a risk that the engine or the like will not be properly controlled. For this reason, there is used a failure diagnosing device that includes a brake pedal switch including a main switch and an auxiliary switch, and determines whether or not the brake pedal switch has a failure based on information from the auxiliary switch. In this type of failure diagnosis device, when it is determined that the main switch is out of order, the warning lamp in the vehicle compartment is turned on to notify the driver of the failure of the brake pedal switch, and the brake for controlling the engine etc. is also provided. By not using the information from the pedal switch (main switch), the inconvenience caused by the failure of the main switch is eliminated early.

As an example of a failure diagnosing device, as shown in FIG. 10, when the brake pedal is depressed from the initial position and moved to reach the first detection position, the output state changes from "0" to "1". Some have an auxiliary switch that switches and a main switch that switches the output state from "0" to "1" when the brake pedal further moves and reaches the second detection position. As a specific method for determining the failure of the main switch, the timer is started when the state of the auxiliary switch is switched from "0" to "1", and then the state of the main switch is set to " A method of determining a failure when not switching from "0" to "1" (hereinafter referred to as a time-based diagnostic method), or the state of the main switch is switched from "0" to "1" as shown in FIG. A method of integrating the number of times when the auxiliary switch state is switched from "0" to "1" without a counter and judging the failure when the integrated value reaches a predetermined value (hereinafter, diagnosis based on the number of times Method).

Further, a so-called play area where the braking function does not work is provided in a predetermined range from the initial position in the movable area of the brake pedal, and the brake lamp is turned on based on the information from the main switch. Therefore, the second detection position is often set in the play area immediately before the braking function is activated.

[0005]

For example, when the driver continues to run the vehicle without stepping on the brake pedal with his / her foot lightly placed, the foot on the brake pedal vibrates due to the vibration of the vehicle and the like. The brake pedal
After reaching the first detection position, there is a possibility of going back and forth in a short time before and after the first detection position without reaching the second detection position. When the brake pedal reciprocates before and after the first detection position, the state of the auxiliary switch is switched between "0" and "1" while the state of the main switch is maintained at "0".

When the brake pedal exhibits such a special behavior, the brake pedal switch is considered to be defective due to this in the time-based diagnostic method and the frequency-based diagnostic method of the above-described conventional failure diagnostic apparatus. It will be judged. That is, in the time-based diagnosis method, it is determined that the failure occurs when the accumulated time when the states of the main switch and the auxiliary switch are both “0” reaches the predetermined time. Further, in the diagnosis method based on the number of times, the number of times is integrated every time the brake pedal reciprocates before and after the first detection position without reaching the second detection position, and when the integrated value of the number reaches a predetermined value. It is judged as a failure.

As described above, in the conventional failure diagnosing device, there is a possibility that the failure may be erroneously determined as a failure depending on the behavior of the brake pedal, even though the main switch is normal.

The present invention has been made in view of the above circumstances, and a failure diagnosis device and a failure diagnosis method for a vehicle switch in which the possibility of erroneous diagnosis due to a use state is reduced and high reliability is obtained. For the purpose of providing.

[0009]

In order to achieve the above object, a vehicle switch failure diagnosis apparatus according to the present invention comprises a main switch, an auxiliary switch, a time accumulating means, a frequency accumulating means, and a failure judging means. And are equipped with.

The main switch detects whether or not a movable member mounted on a vehicle and movable in a predetermined direction from an initial position has reached a first predetermined position. The auxiliary switch detects whether the movable member has reached a second predetermined position between the initial position and the first predetermined position. The time integrating means starts integrating time when the auxiliary switch detects that the movable member has reached the second predetermined position, and moves when the integrated value of this time reaches the first predetermined value. When the main switch detects that the member has reached the first predetermined position, or when the auxiliary switch detects that the movable member has not reached the second predetermined position, the time accumulation is stopped. Clear the integrated value for that time. The number integration means integrates the number of times the integrated value of time has reached the first predetermined value. The failure determination means uses the second integrated value of the number of times
When the predetermined value of is reached, it is determined that the main switch is out of order.

In the above structure, when the movable member moves from the initial position to the first predetermined position, first, when the movable member reaches the second predetermined position, the auxiliary switch detects the movable member, and the time integrating means operates. Start time integration.

If the main switch is normal,
When the movable member reaches the first predetermined position, the main switch detects this, and the time integrating means stops the time integration and clears the integrated value up to that point. Here, the first predetermined value set in the time integrating means should be set longer than the time required for the movable member to move from the second predetermined position to the first predetermined position in a normal use state. For example, the time integration means stops the integration of time before reaching the first predetermined value and clears the integrated value of the time until then, and the number integration means does not integrate the number of times. Therefore, the failure determination means determines that the main switch has not failed, that is, is normal.

On the other hand, if the main switch is out of order,
Even when the movable member reaches the first predetermined position, the main switch does not detect this, and the time integration means continues the time integration. When the integrated value of time reaches the first predetermined value, the time integrating means stops the integration and clears the integrated value of time, and the number of times integrating means performs the integration of the number of times. When the movement of the movable member is repeated, every time the integrated value of time by the time integration means reaches the first predetermined value, the integration of the number of times by the number of times integration means is repeated, and the integrated value of the number of times increases and the second predetermined value increases. When the value is reached, the failure determination means determines that the main switch has failed.

Further, after the movable member reaches the second predetermined position, it has a special behavior such that it reciprocates in a short time before and after the second predetermined position without reaching the first predetermined position. In this case, when the movable member reaches the second predetermined position, the auxiliary switch detects the movable member and the time integrating means starts integrating the time, but the integrated value of this time reaches the first predetermined value. The movable member often returns to the initial position side rather than the second predetermined position before. Therefore, the integration of time is stopped and cleared before the integrated value reaches the first predetermined value. Therefore, the number of times is not accumulated by the number of times accumulating unit, and the failure determining unit does not erroneously determine that the main switch has a failure. It should be noted that the movable member is temporarily maintained between the first predetermined position and the second predetermined position, and the integrated value of time is sporadically before the movable member returns to the initial position side from the second predetermined position. Even when the first predetermined value is reached, the number of times is integrated by the number integration means only once, and unless the integrated value of the number reaches the second predetermined value, the main switch The failure determination means does not erroneously determine that there is a failure.

As described above, according to the present invention, the movable member reciprocates in a short time before and after the second predetermined position without reaching the first predetermined position after reaching the second predetermined position. Even if such an exceptional behavior is exhibited, it is possible to prevent the main switch from being erroneously determined as a failure. Therefore, the possibility of erroneous diagnosis due to the usage state of the movable member is reduced, and high reliability can be obtained.

In the above structure, the number integration means may be configured to clear the integrated number of times when the main switch detects that the movable member has reached the first predetermined position.

In the above configuration, even if the number of times is accumulated by mistake, the accumulated value of the number of times until then is cleared when the main switch is judged to be normal, so that a failure occurs. The judging means can make a more accurate judgment, and the reliability is further improved.

The movable member may be a brake pedal.

Further, the number of times the integrated value of the number of times by the number-of-times integrating means reaches the second predetermined value is further integrated, and when the integrated value reaches the predetermined value, it is determined that the main switch is out of order. May be determined.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a failure diagnosis device for a brake pedal switch will be described below with reference to the drawings.

1 to 3 are schematic views of a failure diagnosis device for a brake pedal switch according to this embodiment. FIG. 1 shows an initial state of the brake pedal, FIG. 2 shows an intermediate state of the brake pedal switch, and FIG. Shows the complete switching state of the brake pedal switch. 4 is the ECM of FIG.
FIG. 5 is a block diagram schematically showing a part of FIG. 5, FIG. 5 is a flowchart showing control of the failure diagnosis program of the present embodiment,
FIG. 6 is a relationship diagram between the state of the brake pedal switch and the position of the brake pedal in each state of FIGS. 1 to 3, and FIG. 7 is a time chart showing the states of the brake pedal switch and the error counter when the main switch is normal. ,
FIG. 8 is a time chart showing the states of the brake pedal switch and the error counter when the main switch is out of order, and FIG. 9 is a time chart showing the states of the brake pedal switch and the error counter when the brake pedal shows a special behavior. It is a chart.

As shown in FIG. 1, the failure diagnosis device 3 for the brake pedal 1 includes a brake pedal switch 5 and an ECM.
(Electric Control Module) 7.

The brake pedal 1 as a movable member is arranged in the lower front part of the driver's seat, and its upper end is rotatably connected to the vehicle body. The lower part of the brake pedal 1 is stepped on by the driver's foot from an initial position close to the driver's foot and moves to the front of the vehicle body. The initial position of the brake pedal 1 is restricted by a stopper (not shown) and a return spring (not shown). That is, the brake pedal 1 is biased toward the initial position by the return spring, and the rotation of the brake pedal 1 rearward of the vehicle body from the initial position is blocked by the stopper.

When the brake pedal 1 is depressed against the urging force of the return spring, the braking device (not shown) of the vehicle operates. In the movable area of the brake pedal 1, a so-called play area in which the braking device does not operate is provided in a predetermined range from the initial position.

The brake pedal switch 5 includes an auxiliary switch Sw1 and a main switch Sw2. The auxiliary switch Sw1 detects that the brake pedal 1 has been stepped on from the initial position and has reached the first detection position (second predetermined position), and outputs it to the ECM 7. Main switch Sw2
Detects that the brake pedal 1 has been further depressed from the first detection position to reach the second detection position (first predetermined position), and outputs it to the ECM 7. Since the brake lamp (not shown) is turned on based on the information from the main switch Sw2, the second detection position is set in the play area immediately before the braking function is activated. In addition, the auxiliary switch Sw
1 is for judging the failure of the main switch Sw2, and it is preferable that the brake pedal switch 5 is small as a whole.
The detection positions are set close to each other.

Next, the brake pedal switch 5 will be described in more detail.

The auxiliary switch Sw1 has two contacts 13,1.
5 and a connection plate 17 that electrically connects the contacts 13 and 15 so as to be openable and closable. One contact 13 is EC
It is connected to M7 and the other contact 15 is grounded.
The output state from the auxiliary switch Sw1 to the ECM7 is "0" when both the contacts 13 and 15 are connected by the connection plate 17 (the state where the auxiliary switch Sw1 is closed), and the connection plate 17 connects both the contacts 13 and 15 to each other. The output state from the auxiliary switch Sw1 to the ECM 7 in the state away from (the state where the auxiliary switch Sw1 is open) is "1".

The main switch Sw2 has two contacts 19,
21 and a connection plate 23 that electrically connects the contacts 19 and 21 so as to be openable and closable. One contact 19 is E
It is connected to the CM 7 and the other contact 21 is connected to the positive electrode 25 of the battery. Connection plate 2 between both contacts 19, 21
The output state from the main switch Sw2 to the ECM7 in the state of being connected by 3 (the state in which the main switch Sw2 is closed) is "1", and the connecting plate 23 has both contacts 19,2.
State away from 1 (state where main switch Sw2 is open)
The output state from the main switch Sw2 to the ECM7 is 0.

Auxiliary switch Sw1 and main switch Sw2
The contacts 13, 15, 19, 21 and the connecting plates 17, 23 are housed in the housing 29 of the brake pedal switch 5, and the connecting plates 17, 23 are connected and supported by the rod 27. The rod 27 is slidably supported with respect to the housing, and extends from the connection plate 17 toward the brake pedal 1 to the outside of the housing. The tip of the rod 27 faces the brake pedal 1 and is pushed and moved by the brake pedal 1 which is depressed and moved.
With the movement of the rod 27, the connection plates 17 and 23 move.

As shown in FIG. 1, in the brake pedal switch 5 in the initial state, the rod 27 is biased by the return spring (not shown) to the most projecting position (shown in FIG. 1) from the housing, and the auxiliary switch Sw1 is activated. When it is closed, “0” is output, and when the main switch Sw2 is opened, “0” is output. While the brake pedal 1 is depressed and moves from the initial position to the first detection position, the tip of the rod 27 is separated from the brake pedal 1, and the brake pedal switch 5 is maintained in the initial state.

When the brake pedal 1 is depressed to reach the first detection position, the brake pedal 1 abuts against the tip of the rod 27 and presses it, the rod 27 moves to the right in FIG. 1, and the brake pedal switch 5 operates. Transition to an intermediate state as shown in FIG. Brake pedal switch 5 in intermediate state
Then, the auxiliary switch Sw1 opens to output "1", and the main switch Sw2 opens to output "0".

When the brake pedal 1 is further depressed to reach the second detection position, the brake pedal switch 5 shifts to the complete switching state as shown in FIG. In the brake pedal switch 5 in the complete switching state, the auxiliary switch Sw1 opens and outputs "1", and the main switch Sw2 closes and outputs "1".

As described above, the output states of the auxiliary switch Sw1 and the main switch Sw2 are changed according to the position of the brake pedal 1. That is, as shown in FIG. 6, in the state A (state shown in FIG. 1) from when the brake pedal 1 reaches the first detection position from the initial position, the output states of the auxiliary switch Sw1 and the main switch Sw2 are both “0”. Thus, only the output state of the auxiliary switch Sw1 is switched to "1" when the brake pedal 1 reaches the first detection position. In the state B (state shown in FIG. 2) from when the brake pedal 1 reaches the second detection position from the first detection position, the output state of the auxiliary switch Sw1 is "1" and the output state of the main switch Sw2 is "0". Yes, the output state of the main switch Sw2 also switches to "1" when the brake pedal 1 reaches the second detection position. In the state C (state shown in FIG. 3) after the brake pedal 1 reaches the second detection position, the output states of the auxiliary switch Sw1 and the main switch Sw2 are both "1".

Next, the ECM 7 will be described in more detail.

As shown in FIG. 4, the ECM 7 includes a timer control unit 31 and a timer 33 which constitute time integration means, a counter control unit 35 and an error counter 37 which constitute frequency integration means, and a failure as failure determination means. Judgment unit 39
And are equipped with.

When the auxiliary switch Sw1 detects that the brake pedal 1 has moved from the initial position and has reached the first detection position (the output state of the auxiliary switch Sw1 is from "0" to "1"). (When switched to “”, the timer 33 is controlled to start the integration of time. When the integrated value (timer count value) Ti of this time reaches a preset timer specified value (first predetermined value) Tp,
When the main switch Sw2 detects that the brake pedal 1 has reached the second detection position (main switch Sw2
When the output status of is switched from "0" to "1"),
Alternatively, when the auxiliary switch Sw1 detects that the brake pedal 1 has not reached the first detection position (auxiliary switch Sw
In either case (when the output state of 1 returns to “0”), the timer 33 stops counting the time and clears the timer count value Ti. The timer specified value Tp is
It is set to be longer than the time required for the brake pedal 1 to move from the first detection position to the second detection position when the driver depresses the brake pedal 1 to utilize the brakes during normal vehicle traveling. ing.

The counter control unit 35 integrates the integrated value (error count value) Ec of the number of times by the error counter 37 every time the timer count value Ti reaches the timer specified value Tp. Further, the counter control unit 35 notifies the main switch Sw2 that the brake pedal 1 has reached the second detection position.
Is detected (when the output state of the main switch Sw2 is switched from "0" to "1"), the error count value Ec is cleared.

The failure judging section 39 determines the error count value Ec.
Has reached the error count specified value (second predetermined value) Ep, it is determined that the main switch Sw2 has failed. When it is determined that the main switch Sw2 is out of order, the ECM 7 turns on a warning lamp (not shown) in the vehicle compartment to notify the driver of the brake pedal switch 5
Of the main switch Sw2 of the engine is notified, and the engine, AT (Automatic Transmission) and ABS (Antil
Main switch Sw2 for controlling the Bock System)
Temporarily stop using information from.

Next, the control of the failure diagnosis program in the ECM 7 will be described in more detail with reference to the flowchart of FIG.

By inserting the key into the key cylinder and turning it to the accessory position, the timer control unit 31, the timer 33, the counter control unit 35, the error counter 37,
And the failure determination unit 39 is turned on, and the process proceeds to step S1.

In step S1, the counter control unit 35 resets the error count value Ec of the error counter 37 to 0, the timer control unit 31 resets the timer count value Ti of the timer 33 to 0, and the process proceeds to step S2.

In step S2, the failure determination section 39 determines whether the output states of the auxiliary switch Sw1 and the main switch Sw2 are both "0". That is, when the brake pedal 1 is not depressed as a determination start condition in this control, and both the auxiliary switch Sw1 and the main switch Sw2 are “0” (when the brake pedal 1 is not depressed), The process proceeds to step S3 to start the determination by this control.

On the other hand, when one of the auxiliary switch Sw1 and the main switch Sw2 is "1" (when the brake pedal 1 is already depressed), both the auxiliary switch Sw1 and the main switch Sw2 are changed to "0". The determination in this step is repeated (until the depression of the brake pedal 1 is released).

In step S3, the failure determination section 39 determines whether the output state of the auxiliary switch Sw1 and the output state of the main switch Sw2 are different. If they are not different (equal to each other), the output states of the auxiliary switch Sw1 and the main switch Sw2 are both "0", and it is determined that the brake pedal 1 has not been depressed, so the process returns to step S2.

On the other hand, when the output states of the auxiliary switch Sw1 and the main switch Sw2 are different, the auxiliary switch Sw1
Since the output state of Sw1 is "1" and it is determined that the brake pedal 1 has been depressed and reached the first detection position, the process proceeds to step S4.

In step S4, the timer control unit 31 controls the timer 33 to start the integration of the timer count value Ti, and the process proceeds to step S5.

In step S5, the failure determination unit 39 compares the timer count value Ti with the timer specified value Tp. If the timer count value Ti is smaller than the timer specified value Tp, the process proceeds to step S6.

In step S6, the failure determination unit 39 determines whether the output state of the auxiliary switch Sw1 and the output state of the main switch Sw2 are different. When they are different, the output state of the auxiliary switch Sw1 is "1" and the output state of the main switch Sw2 is "0". In this case, since the brake pedal 1 exists between the first detection position and the second detection position, the output state of the main switch Sw2 may be “0”, and the brake pedal 1 may be set to the second detection position. However, there is a possibility that the output state of the main switch Sw2 is "0" because the main switch Sw2 is out of order. Therefore, immediately switch the main switch Sw2
Does not determine that is broken, and returns to step S5. That is, while the timer count value Ti is smaller than the timer specified value Tp, the output state of the auxiliary switch Sw1 is "1" and the output state of the main switch Sw2 is "0", the control of steps S5 and S6 is repeated. .

The timer count value Ti is the timer specified value Tp.
Output state of the main switch Sw2 is "1" before reaching
Switch (when both switches Sw1 and Sw2 are both "1"), or when the output state of the auxiliary switch Sw1 is switched to "0" (both switches Sw1 and Sw2 are both "0"). Time), the process proceeds from step S6 to step S7.

In step S7, the timer controller 31
The timer 33 stops counting the timer count value Ti, resets the timer count value Ti to 0, and proceeds to step S8.

In step S8, the failure determination unit 39 determines whether the output states of the auxiliary switch Sw1 and the main switch Sw2 are both "0". Both switches Sw1, Sw
When both 2 are not "0", it is determined in step S6 that the states of both switches Sw1 and Sw2 are "1". In this case, as shown in FIG. 7, in the brake pedal switch 5, the auxiliary switch Sw1 is "0".
Since the main switch Sw2 is switched from "0" to "1" after the switch from "1" to "1" and before the timer specified value Tp elapses, it is determined that the main switch Sw2 is functioning normally. Go to step S9.

In step S9, the counter control unit 35
Resets the error count value Ec of the error counter 37 to 0, returns to step S2, and repeats this control.

In step S8, both switches Sw1,
When it is determined that both Sw2 are “0”, as shown in FIG. 9, in the brake pedal switch 5, after the auxiliary switch Sw1 is switched from “0” to “1”, the timer specified value Tp has elapsed. The main switch Sw2 is "0" before
Since the auxiliary switch Sw1 is switched from "0" to "1" without switching from "1" to "1", the brake pedal 1 reaches the first detection position without being fully depressed and then reaches the second detection position. It is determined that there is a very high possibility that it has moved to the initial position side from the first detection position. Therefore, it is not possible to accurately determine whether the main switch Sw2 is functioning normally or is out of order, and therefore the process returns to step S2 while maintaining the error count value Ec in the state at that time, and this control is repeated.

In step S5, when the timer count value Ti reaches the timer specified value Tp, the brake pedal switch 5 has the auxiliary switch Sw as shown in FIG.
Even if the timer specified value Tp elapses after 1 is switched from "0" to "1", the auxiliary switch Sw1 is kept at "1" and the main switch Sw2 is kept at "0". It is determined that the main switch Sw2 does not switch to "1" even when 1 is fully depressed to reach the second detection position, that is, there is a possibility that the main switch Sw2 is out of order, and the process proceeds to step S10.

In step S10, the timer controller 31
Stops the counting of the timer count value Ti by the timer 33, resets the timer count value Ti to 0, and proceeds to step S11.

In step S11, the counter controller 35
However, 1 is added to the error count value Ec of the error counter 37, and the process proceeds to step S12.

In step S12, the failure determination section 39
It is determined whether the error count value Ec is greater than or equal to the error count specified value Ep. When the error count value Ec is equal to or greater than the error count specified value Ep, it is determined that the main switch Sw2 has failed, and when the error count value Ec is less than the error count specified value Ep, the process returns to step S2 to perform this control. repeat.

As described above, in the present embodiment, when the driver depresses the brake pedal 1 to utilize the brake and the brake pedal 1 moves and reaches the first detection position, the auxiliary switch Sw1 detects the brake pedal 1. (Auxiliary switch Sw1 switches from "0" to "1"), timer 3
3 starts integrating the timer count value Ti.

If the main switch Sw2 is normal, FIG.
As shown in, when the brake pedal 1 is fully depressed to reach the second detection position, the main switch Sw2 detects this (the main switch Sw2 switches from "0" to "1"), and the timer control unit 31 is the timer count value Ti
And the timer count value Ti is reset to 0. Here, the timer specified value Tp set in the timer control unit 31 is the second detection from the first detection position by the brake pedal 1 when the driver depresses the brake pedal 1 in order to utilize the brake during normal vehicle traveling. Since it is set to be longer than the time required to move to the position, the timer control unit 31 stops the accumulation of the timer count value Ti before the timer count value Ti reaches the timer specified value Tp, and Is reset to 0, and the counter control unit 35 does not integrate the error count value Ec. Therefore, the failure determination unit 39 determines that the main switch Sw2 has not failed, that is, is normal.

On the other hand, if the main switch Sw2 is out of order, as shown in FIG. 8, even if the brake pedal 1 reaches the second detection position, the main switch Sw2 does not detect it (the main switch Sw2 becomes "0"). ”Is maintained), the timer control unit 31 continues to integrate the timer count value Ti.
Then, when the timer count value Ti reaches the timer specified value Tp, the timer control unit 31 stops the integration of the timer count value Ti and resets it to 0, and the counter control unit 35
The error count value Ec is integrated. Brake pedal 1
When the movement of is repeated, the error count value Ec is repeatedly accumulated each time the timer count value Ti reaches the timer specified value Tp, and when the error count value Ec increases and reaches the error count specified value Ep, the failure judgment is made. Part 39 is
It is determined that the main switch Sw2 is out of order.

In addition, for example, the driver operates the brake pedal 1
If the vehicle continues to run without stepping on with the foot lightly placed, the foot on the brake pedal 1 vibrates due to the vibration of the vehicle, etc., and after this, the brake pedal 1 reaches the first detection position. However, there are cases where a special behavior is shown in which the vehicle moves back and forth in a short time before and after the first detection position without reaching the second detection position. At this time, the brake pedal switch 5 repeats the initial state shown in FIG. 1 and the intermediate state shown in FIG. 2, and as shown in FIG. 9, the state of the main switch Sw2 is maintained at "0" and the auxiliary switch Sw1 is kept. State switches between "0" and "1". Auxiliary switch Sw1
Is switched to “1”, the timer control unit 31 starts integrating the timer count value Ti, but in most cases,
Since the brake pedal 1 returns to the initial position side from the first detection position before the timer count value Ti reaches the timer specified value Tp (the auxiliary switch Sw1 returns to “0”), the timer count value Ti becomes The integration is stopped and reset to 0 before the timer specified value Tp is reached. Therefore, the error count value Ec by the counter control unit 35
Of the main switch
You can not mistakenly judge that Sw2 is out of order. It should be noted that the brake pedal 1 is temporarily maintained between the second detection position and the first detection position, and before the auxiliary switch Sw1 returns to "0", the timer count value Ti is sporadically set to the timer specified value Tp. Even if the count has reached the limit, the counter control unit 35 adds 1 to the error count value Ec.
Only once, unless the error count value Ec reaches the error count specified value Ep, the main switch Sw
The failure determination unit 39 does not erroneously determine that 2 is defective.

As described above, according to the present invention, the brake pedal 1 reciprocates in a short time before and after the first detection position without reaching the second detection position after reaching the first detection position. Even if the behavior is exceptional, it is possible to avoid erroneously determining that the main switch Sw2 is out of order. Therefore, the possibility of erroneous diagnosis due to the usage state of the brake pedal 1 is reduced, and high reliability can be obtained.

Further, the counter control unit 35 informs the main switch Sw that the brake pedal 1 has reached the second detection position.
When 2 is detected, the error count value Ec is reset to 0. Therefore, even if the error count value Ec is erroneously integrated, the main switch Sw
Since the error count value Ec up to then is cleared when it is determined that 2 is normal, the failure determination unit 39 can make a more accurate determination, and the reliability is further improved.

Further, a counter for further integrating the number of times the error count value Ec has reached the specified error count value Ep is further provided, and when the integrated value reaches a predetermined value, it is determined that the main switch Sw2 is out of order. It may be configured such that 39 makes a judgment.

Furthermore, in the present embodiment, an example in which the present invention is applied to a brake pedal switch is shown, but the present invention is not limited to this, and a movable member such as an air conditioner switch or a clutch switch is detected. It can be applied to various switches for vehicles for operating.

[0066]

As described above, according to the present invention,
After the movable member reaches the second predetermined position, it does not reach the first predetermined position, but exhibits an exceptional behavior such as reciprocating in a short time before and after the second predetermined position. Also,
It is avoided that the main switch is mistakenly determined to be a failure. Therefore, the possibility of erroneous diagnosis due to the usage state of the movable member is reduced, and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an initial state of a brake pedal switch in a failure diagnosis device according to this embodiment.

FIG. 2 is a schematic diagram showing an intermediate state of a brake pedal switch in the failure diagnostic device of FIG.

FIG. 3 is a schematic diagram showing a complete switching state of a brake pedal switch in the failure diagnostic device of FIG.

FIG. 4 is a block diagram schematically showing a part of the ECM shown in FIG.

FIG. 5 is a flowchart showing control of a failure diagnosis program of this embodiment.

FIG. 6 is a relationship diagram between the state of the brake pedal switch and the position of the brake pedal in each state of FIGS. 1 to 3.

FIG. 7 is a time chart showing the states of the brake pedal switch and the error counter when the main switch is normal.

FIG. 8 is a time chart showing the states of the brake pedal switch and the error counter when the main switch is out of order.

FIG. 9 is a time chart showing the states of the brake pedal switch and the error counter when the brake pedal shows a special behavior.

FIG. 10 is a relationship diagram between the state of a conventional brake pedal switch and the position of the brake pedal.

FIG. 11 is a time chart showing a special behavior of the brake pedal.

[Explanation of symbols]

1 Brake pedal (movable member) 3 Failure diagnosis device 5 Brake pedal switch (vehicle switch) 7 ECM 31 Timer control unit (time integration means) 33 timer (time integration means) 35 Counter Control Unit (Number Accumulation Means) 37 Error counter (count integration means) 39 Failure determination unit (failure determination means) Sw1 auxiliary switch Sw2 main switch Ti timer count value (time integrated value) Tp timer specified value (first predetermined value) Ec error count value (total number of times) Ep error count specified value (second predetermined value)

Claims (4)

[Claims] 1. A main switch for detecting whether or not a movable member mounted on a vehicle and movable in a predetermined direction from an initial position has reached a first predetermined position, the movable member having the initial position and the first switch. And an auxiliary switch for detecting whether or not the movable member has reached a second predetermined position, and a time when the auxiliary switch detects that the movable member has reached the second predetermined position. Is started, and when the integrated value of this time reaches a first predetermined value, when the main switch detects that the movable member has reached the first predetermined position, or when the movable member is When the auxiliary switch detects that the second predetermined position has not been reached, time integration means for stopping the integration of the time and clearing the integrated value, and the integrated value of the time is the first integrated value. Number of times the specified value is reached And a failure determination means for determining that the main switch has a failure when the integrated value of the number of times by the number of integration means reaches a second predetermined value. A vehicle switch failure diagnosis device characterized by: 2. The vehicle switch failure diagnosing device according to claim 1, wherein the number-of-times integrating means detects that the movable member has reached the first predetermined position. In addition, the vehicle switch failure diagnosis device is characterized in that the integrated value of the number of times is cleared. 3. The vehicle switch failure diagnosis device according to claim 1 or 2, wherein the movable member is a brake pedal. 4. A step of detecting by a main switch whether or not a movable member mounted on a vehicle and movable in a predetermined direction from an initial position has reached a first predetermined position; Detecting whether a second predetermined position between the first predetermined position and the movable member has reached the second predetermined position, and integrating the time when it is detected that the movable member has reached the second predetermined position. Starting, the integrated value of the time reaches a first predetermined value, it is detected that the movable member has reached the first predetermined position, or the movable member is No. 2, the step of stopping the integration of the time and clearing the integrated value when it is detected that the time has not reached the predetermined position, and the number of times the integrated value of the time has reached the first predetermined value. Steps to accumulate and previous When the integrated value of the count has reached the second predetermined value, step a failure diagnosis for the switch for a vehicle, comprising the to determining that the main switch has failed.