JPH11272504A - Computer monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a computer monitoring device which can secure safe operation even when a power source voltage supplied to a microcomputer is lowered and the microcomputer is in abnormal state. SOLUTION: In order to supply the power with a microcomputer monitoring circuit 14 and a signal processing circuit 16 when a power source voltage supplied by a microcomputer power source 18 lowers, an auxiliary power source 20 for supplying a slightly lower voltage than the voltage the microcomputer 18 supplies is provided. If the power source voltage supplied by the microcomputer power source 18 lowers, a potential of the auxiliary power source 20 becomes higher than the potential of a point D and so the power is supplied with the microcomputer monitoring circuit 14 and the signal processing circuit 16 by way of a diode 26. Thus, since the microcomputer monitoring circuit 14 and the signal processing circuit 16 can successively operate, it is possible to perform processing for securing safe operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer monitoring device for monitoring whether or not a computer applied to control such as detection of a window ascending and descending of a power window system of a vehicle and detection of a foreign object being caught is operating normally.

[0002]

2. Description of the Related Art Conventionally, in a system using a microcomputer (hereinafter referred to as a microcomputer) such as a power window system for a vehicle, the microcomputer uses a stabilized power supply that is controlled at a constant voltage based on a voltage obtained from a battery. Working (about 5V). Here, a microcomputer monitoring circuit (a so-called watchdog timer) prevents an erroneous operation (for example, an operation of a power window contrary to the intention of a switch operation due to latch-up of an active signal or the like) when the microcomputer becomes abnormal. Circuit) to monitor the operating state of the microcomputer.

Specifically, when the microcomputer is operating normally, a pulse signal is output to the microcomputer monitoring circuit at a predetermined cycle, and the microcomputer monitoring circuit operates normally while detecting the pulse signal. Judge that you are doing. If the pulse signal cannot be detected for a predetermined time or more, the microcomputer determines that the microcomputer is in an abnormal state and outputs a signal for inhibiting communication with the microcomputer to a signal processing circuit for outputting a signal for operating the power window. In addition, the power window is prevented from malfunctioning, and a reset signal is output to the microcomputer to restart the microcomputer.

[0004] In this way, the safe operation in the abnormal state of the microcomputer is ensured. However, when the power supply to the microcomputer monitoring circuit is shared with the power supply to the microcomputer, when the power supply voltage supplied to the microcomputer decreases. The power supply voltage supplied to the microcomputer monitoring circuit also drops, and there is a problem that it is not possible to ensure a safe operation for preventing a malfunction of the power window due to a microcomputer abnormality.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a computer monitoring device capable of ensuring a safe operation even when the power supply voltage supplied to the microcomputer drops and the microcomputer becomes abnormal. Is the purpose.

[0006]

According to one aspect of the present invention, there is provided a computer monitoring device provided in a controller for operating a controlled device in accordance with a program installed in a computer. A power supply circuit for supplying power to the computer, operated by power supplied from the power supply circuit, a monitoring circuit for monitoring an operation state of the computer, and operated by power supplied from the power supply circuit; An abnormality processing circuit that performs processing when the computer operates abnormally; an auxiliary power supply that can supply power to at least the monitoring circuit and the abnormality processing circuit; and a voltage value of power supplied from the power supply circuit is a predetermined voltage value. Switching means for switching to the auxiliary power supply when the power is lower than the above.

According to the first aspect of the present invention, an auxiliary power supply is provided for the case where the power supply voltage supplied from the power supply circuit is reduced, and the power supply voltage supplied from the power supply circuit is reduced to cause an abnormal state of the computer. In this case, the power is switched to the auxiliary power supply by the switching means to supply power to the monitoring circuit and the abnormality processing circuit. Therefore, the monitoring circuit and the abnormality processing circuit can continue to operate, so that a process for ensuring a safe operation can be performed.

According to a second aspect of the present invention, the switching means includes:
An anode side is connected to each output terminal of the power supply circuit and the auxiliary power supply, and a pair of diodes are connected so that a cathode side is common.

According to the second aspect of the present invention, the switching means is constituted by a pair of diodes connected to the respective output terminals of the power supply circuit and the auxiliary power supply on the anode side and the cathode side in common. It is possible to switch to the auxiliary power supply with a simple configuration, and to suppress power supply interference with each other.

According to a third aspect of the present invention, the auxiliary power supply includes:
It operates effectively only when a predetermined signal is input.

According to the third aspect of the present invention, the operation of the auxiliary power supply is made effective only when there is a predetermined signal input, that is, when a safe operation must be ensured. It is possible to suppress an increase in current consumption in a standby state where there is no power supply.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a computer monitoring device 10. The computer monitoring device 10 includes a microcomputer (hereinafter, referred to as a microcomputer) 12, a microcomputer monitoring circuit 14, a signal processing circuit 16, and a microcomputer, which are configured by connecting a CPU (not shown), a RAM, a ROM, and various interfaces via a bus. Power supply 18,
An auxiliary power supply 20 is provided.

The signal processing circuit 16 performs processing according to the input signals 1 and 2 and transmits the signal A to the microcomputer 12. The microcomputer 12 performs processing based on the signal A output from the signal processing circuit 16 and outputs a signal B to the signal processing circuit 16. The signal processing circuit 16 performs signal processing based on the signal B output from the microcomputer 12 and outputs an output signal C. In the present embodiment, as an example, signal 1 is an ignition signal of the vehicle, and signal 2 is an UP signal or DO for raising and lowering a door glass 100 described later.
The WN signal and the output signal C are signals for driving a motor 52 for raising and lowering the door glass 100 described later.

FIG. 2 shows the internal structure of the door 12 on the driver's seat side of the vehicle. As shown in FIG. 2, a motor 52 is provided inside the driver's seat door. Motor 52
Is connected to a window regulator section 46. The window regulator 46 is a so-called wire type in the present embodiment, and an intermediate portion of a wire (not shown) is wound around a rotary plate 52A attached to a drive shaft of the motor 52. The ends of the wires are each connected to a holding channel 54 that supports the lower end of the door glass 100,
Is attached to the main guide 56 so as to be vertically movable.

As a result, when the motor 52 rotates in the forward and reverse directions, this rotational driving force is transmitted through the wire, and
The door glass 100 moves up and down (up and down) along the glass guide 48. The configuration of the window regulator unit 46 is not limited to such a wire type, but may be an X-arm type,
A so-called motor self-propelled type in which the motor itself moves along the rack may be used.

The door glass 10 is driven by the drive of the motor 52.
0 is raised, the peripheral edge of the door glass 100
The opening of the door frame 42A is closed by fitting into a rubber weather strip (not shown) in the second frame 42A. When the door glass 100 is moved downward by the rotation of the motor 52, the frame 4
2A opening is opened.

When a switch (not shown) is operated to raise and lower the door glass 100 and an UP signal or a DOWN signal is input to the signal processing circuit 16 as a signal 2, the signal processing circuit 16 performs processing based on the signal 2. Do
The signal is transmitted to the microcomputer 12 as a signal A. The microcomputer 12 performs processing in accordance with the signal A, and outputs the signal B to the signal processing circuit 1.
Output to 6. The signal processing circuit 16 performs processing according to the signal B, outputs an output signal C for driving the motor 52, drives the motor 52, and
0 is raised and lowered.

The microcomputer 12 is connected to a microcomputer monitoring circuit 14 for detecting an abnormal operation of the microcomputer 12, and outputs a cancel pulse signal to the microcomputer monitoring circuit 14 at a predetermined cycle. Also, it is restarted by a reset signal output from the microcomputer monitoring circuit 14.

The microcomputer monitoring circuit 14 determines that the microcomputer 12 is operating normally while the cancel pulse signal output from the microcomputer 12 at a predetermined cycle is input, and sends a reset signal to the microcomputer 12. Is not output, and the microcomputer state determination signal output to the signal processing circuit 16 is made normal (for example, high level).

When the cancel pulse signal has not been detected for a predetermined time or more, the microcomputer 12 determines that the microcomputer 12 is abnormal, outputs a reset signal to the microcomputer 12, restarts the microcomputer 12, and sends the signal to the signal processing circuit 16. Abnormal output microcomputer status judgment signal (for example, low level)
To In this case, the signal processing circuit 16 outputs the output signal C
Communication with the microcomputer 12, that is, the output of the signal A and the reception of the signal B are prohibited so that the door glass 100 does not operate abnormally when the door glass 100 moves abnormally.
Outputs an output signal C (for example, a motor stop signal) for preventing abnormal operation.

Also, the microcomputer monitoring circuit 14 outputs a reset signal to the microcomputer 12 even when the voltage supplied to the microcomputer 12 becomes lower than a voltage at which the microcomputer 12 can operate normally, restarts the microcomputer 12, and outputs a cancel pulse signal. The same operation is performed as when no detection has been performed for a longer time.

The microcomputer power supply 18 is connected to the microcomputer monitoring circuit 1
4. It is connected to the microcomputer 12 and converts the voltage supplied from the power supply 22 to a predetermined voltage (5 V in this embodiment as an example) and supplies it to the microcomputer monitoring circuit 18 and the microcomputer 12. The anode side of the diode 24 is connected to the microcomputer power supply 18, and the cathode side is connected to the cathode side of the diode 26, the microcomputer monitoring circuit 14, and the signal processing circuit 16.

The anode side of the diode 26 is connected to the auxiliary power supply 20, and the cathode side is connected to the diode 24.
, The microcomputer monitoring circuit 14, the signal processing circuit 1
6 is connected. The auxiliary power supply 20 has a voltage supplied from the power supply 22 slightly lower than the voltage supplied from the microcomputer power supply 18, and a voltage at which the microcomputer monitoring circuit 14 and the signal processing circuit 16 can operate (for example, 4 V in this embodiment). ), And supplies it to the microcomputer monitoring circuit 14 and the signal processing circuit 16 via the diode 26.

At this time, the potential at point D shown in FIG.
It becomes about 3V. For this reason, since the potential at the point D is higher than the potential of the auxiliary power supply 20, no current flows through the diode 26, and the current supplied from the microcomputer power supply 18 flows through the diode 24, and the microcomputer monitoring circuit 14 and the signal processing It is supplied to the circuit 16. That is, the configuration is such that the microcomputer power supply 18 is automatically switched to the auxiliary power supply 20.

If the power supply voltage supplied from the microcomputer power supply 18 drops due to, for example, a short-circuit between the power supply and the ground, the potential at the point D also decreases, and the potential of the auxiliary power supply 20 becomes higher. Therefore, the current supplied from the auxiliary power supply 20 flows through the diode 26 and is supplied to the microcomputer monitoring circuit 14 and the signal processing circuit 16.

As described above, when the microcomputer power supply 18 is normal, power is supplied from the microcomputer power supply 18 to the microcomputer monitoring circuit 14 and the signal processing circuit 16, and the microcomputer power supply 1
In the event that 8 is abnormal, power is supplied from the auxiliary power supply 20 to the microcomputer monitoring circuit 14 and the signal processing circuit 16. Also,
A diode OR circuit 28 composed of the diodes 24 and 26 can prevent interference between power supplies.

Further, an ignition signal (signal 1) is input to the auxiliary power supply 20. It operates only when this ignition signal is on (the power window is operable, so it is necessary to ensure safe operation), so when the ignition signal is off (standby because the power window is inoperable, In this case, it is not necessary to ensure safe operation), so that the current consumption does not increase.

Further, the auxiliary power supply 20 may be operated effectively when the ignition signal is off. In such a case, it becomes possible to apply to an anti-theft system.

Next, the operation of the embodiment of the present invention will be described in detail with reference to the drawings.

When the microcomputer 12 is supplied with power by the microcomputer power supply 18, the microcomputer 12 starts to start. Microcomputer monitoring circuit 1
4 indicates that the microcomputer 12 is activated when the microcomputer 12 is started.
Start monitoring whether is working properly. Microcomputer 1
While the cancel pulse signal output from 2 is detected, the microcomputer 12 determines that the microcomputer 12 is in a normal state, and sets the microcomputer state determination signal output to the signal processing circuit 16 to a high level (normal).

When a switch (not shown) for raising and lowering the door glass 100 is operated, an UP signal or DOWN signal is output.
When the signal is input to the signal processing circuit 16 as the signal 2,
The signal processing circuit 16 performs processing based on the signal 2 and transmits the signal A to the microcomputer 12. Microcomputer 1
At 2, the signal is processed according to the signal A and the signal B is output to the signal processing circuit 16. Then, the signal processing circuit 16 performs processing according to the signal B, outputs an output signal C for driving the motor 52, drives the motor 52, and moves the door glass 100 up and down.

Here, when the power supply voltage supplied from the microcomputer power supply 18 drops and the microcomputer 12 becomes abnormal, the potential at the point D also drops, so that the potential of the auxiliary power supply 20 becomes higher. The current supplied from the auxiliary power supply 20 flows through the diode 26 and is supplied to the microcomputer monitoring circuit 14 and the signal processing circuit 16. Therefore, the microcomputer monitoring circuit 14 and the signal processing circuit 16 can continue to operate normally.

In the microcomputer monitoring circuit 14, the microcomputer 12
Is in an abnormal state.
2 and restart, and the signal processing circuit 16
Set the microcomputer determination signal to be output to low level (abnormal).

In the signal processing circuit 16, since the microcomputer determination signal output from the microcomputer monitoring circuit 14 is abnormal, communication with the microcomputer 12, that is, transmission and reception of the signal A and the signal B is prohibited, and the door glass 100 is raised and lowered. A motor stop signal is output as the output signal C so as not to cause an abnormal operation. Therefore, the door glass 100 does not operate abnormally.

The auxiliary power supply 20 operates only when the ignition signal (signal 1) is on (the power window is operable, so that it is necessary to ensure safe operation). Therefore, the auxiliary power supply 20 is in a standby state in which the ignition signal is off. In the case of (the power window cannot be operated, it is not necessary to ensure the safe operation), the unnecessary current consumption can be suppressed.

When the input of the signal 1 can be used also as the power supply input, the input of the signal 1 is input to the auxiliary power supply 20 as the power supply input to operate the auxiliary power supply 20, as shown in FIG. Can also. Further, if the microcomputer monitoring circuit 14 can be configured so that the microcomputer state determination signal output from the microcomputer monitoring circuit 14 becomes abnormal when the power supply voltage supplied from the microcomputer power supply 18 drops, it is indicated by a dotted line in the figure. The auxiliary power supply line 34 can be deleted.

Next, another example of the computer monitoring apparatus according to the present invention is shown in FIG. The same parts as those of the computer monitoring device 10 shown in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted.

The computer monitoring device 30 shown in FIG.
A 5V regulator circuit 32 with a built-in watchdog timer incorporating a watchdog timer (microcomputer monitoring circuit) is provided. The 5V regulator circuit 32 with a built-in watchdog timer adjusts the power supply voltage supplied from the power supply 22 to 5V.
And supplies it to the signal processing circuit 16 and the microcomputer 12, and monitors the operating state of the microcomputer 12.

When the microcomputer 12 is normal (when a cancel pulse signal is detected), the microcomputer state determination signal is at a high level (normal). When the microcomputer 12 is abnormal (the cancel pulse signal cannot be detected for a predetermined time or more), the microcomputer 12 outputs a reset signal to the microcomputer 12 to restart it, and sets the microcomputer state determination signal to low level (abnormal). In this case, since the microcomputer 12 is in an abnormal state, the signal processing circuit 16 outputs a motor stop signal as an output signal C, and secures a safe operation so that the door glass 100 does not abnormally operate.

When the power supply voltage supplied by the 5V regulator circuit 32 with a built-in watchdog timer drops, the potential at point E in the figure becomes lower than the potential of the auxiliary power supply 20. Power is supplied and processing can continue. In this case, since the microcomputer state determination signal becomes low level, the signal processing circuit 1
In step 6, the same process as described above for ensuring the safe operation is performed.

When the input of the signal 1 can be used as the power supply input, the input of the signal 1 is input to the auxiliary power supply 20 as the power supply input to operate the auxiliary power supply 20, as shown in FIG. Can also.

As described above, when the power supply voltage of the microcomputer power supply 18 falls, the microcomputer power supply is switched to the auxiliary power supply 20 to operate the microcomputer monitoring circuit 14 and the signal processing circuit 16. Safe operation of the window can be ensured.

In this embodiment, the case where the present invention is applied to a power window system has been described. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to an airbag system and the like.

[0045]

As described above, according to the first aspect of the present invention,
According to the described invention, an auxiliary power supply is provided for when the power supply voltage supplied from the power supply circuit decreases, and when the power supply voltage supplied from the power supply circuit decreases and the computer becomes abnormal, Since the auxiliary power supply is configured to supply power to the monitoring circuit for monitoring the operation state of the computer and the abnormality processing circuit that performs processing when the computer operates abnormally, the monitoring circuit and the abnormality processing circuit can continue to operate. It is possible to perform a process for ensuring a safe operation.

According to the second aspect of the present invention, the switching means is constituted by a pair of diodes connected such that the anode side is connected to the output terminals of the power supply circuit and the auxiliary power supply and the cathode side is connected in common. It is possible to switch to the auxiliary power supply with a simple configuration, and to suppress power supply interference with each other.

According to the third aspect of the present invention, the operation of the auxiliary power supply is operated only when a predetermined signal is input, that is, when the safe operation must be ensured, so that the standby without the signal input is performed. An increase in current consumption in the state can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a computer monitoring device according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing an internal structure of a driver side door of the vehicle according to the embodiment of the present invention.

FIG. 3 is a block diagram showing another example of the computer monitoring device according to the embodiment of the present invention.

FIG. 4 is a block diagram showing another example of the computer monitoring device according to the embodiment of the present invention.

FIG. 5 is a block diagram showing another example of the computer monitoring device according to the embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 computer monitoring device 12 microcomputer 14 microcomputer monitoring circuit 16 signal processing circuit 18 microcomputer power supply 20 auxiliary power supply 24, 26 diode 32 5V regulator circuit with built-in watchdog timer

Claims (3)

[Claims] 1. A computer monitoring device provided in a controller that operates a controlled device according to a program installed in a computer, comprising: a power supply circuit for supplying power to the computer; and a power supply from the power supply circuit. A monitoring circuit for monitoring the operation state of the computer, an abnormality processing circuit that is operated with electric power supplied from the power supply circuit and performs processing when the computer operates abnormally, at least the monitoring circuit and A computer monitor comprising: an auxiliary power supply capable of supplying power to the abnormality processing circuit; and switching means for switching to the auxiliary power supply when the voltage value of the power supplied from the power supply circuit falls below a predetermined voltage value. apparatus. 2. The switching means, wherein an anode side is connected to each output terminal of the power supply circuit and the auxiliary power supply,
2. The computer monitoring apparatus according to claim 1, wherein a pair of diodes are connected so as to have a common cathode side. 3. The apparatus according to claim 1, wherein the auxiliary power supply operates effectively only when a predetermined signal is input.
Alternatively, the computer monitoring device according to claim 2.