JP2002362322A - Controller for on-vehicle electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller capable of driving an on-vehicle electrical apparatus without misidentifying an operation even when there is a fluctuation of a power supply voltage. SOLUTION: An output of a control signal to a wiper driving circuit is controlled on the basis of a minimum operating voltage VMmin of the wiper driving circuit. A CPU circuit monitors the power supply voltage, it recognizes the VMmin, and when the power supply voltage drops and becomes lower than the VMmin, it stops the output of the control signal to the wiper control circuit. Then, if the power supply voltage becomes lower than a minimum operating voltage VCmin of the CPU circuit, the CPU circuit stops operating. When the power supply voltage recovers to the VCmin or more, the CPU circuit starts to operate, while the output of the control signal to the wiper driving circuit is stopped until the power supply voltage becomes the VMmin or more. The control signal is not outputted even though the CPU circuit recovers first, and misidentification by the CPU circuit of a motor lock and operation of a fail safe mode can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling the driving of various electric components mounted on a vehicle, such as a wiper motor and a power window motor, and more particularly to a control device having a minimum operating voltage and being affected by fluctuations in a power supply voltage. The present invention relates to a technology that is effective when applied to control of on-vehicle electrical components.

[0002]

2. Description of the Related Art In recent years, systems for controlling on-vehicle electrical components such as a power window motor and a wiper motor by a CPU have been widely used for the purpose of improving the commerciality of vehicles such as automobiles. In such a system, the lowest voltage at which the operation of the system is guaranteed is determined by the portion having the highest lowest operating voltage in the system. Generally, the voltage is set to be the lowest. For example, in a control system of a wiper device, CP
The minimum operating voltage of the U circuit is lower than that of the motor drive circuit.

FIG. 3 is an explanatory diagram showing the operation of the CPU circuit when the power supply voltage fluctuates in the control system of the conventional wiper device. As shown in FIG. 3, when the power supply voltage decreases due to the driving of the starter motor or the like and becomes lower than the minimum operating voltage VMmin of the motor drive circuit, the motor drive circuit first stops, and the motor also stops there. At this time, since the power supply voltage is still higher than the minimum operating voltage VCmin of the CPU circuit, the operating state of the CPU circuit is maintained. Thereafter, when the power supply voltage becomes lower than VCmin, the CPU circuit also stops operating, and the output of the control signal to the motor drive circuit also stops.

[0004]

On the other hand, when the power supply voltage gradually recovers and becomes equal to or higher than VCmin, the CPU circuit is first recovered. With the resurrection, the CPU circuit sends a control signal to the motor drive circuit. However, at this time, since the power supply voltage has not yet reached VMmin, the motor drive circuit does not operate even when the control signal is received, and the motor does not operate.

[0005] Here, if the motor does not operate within a certain period of time after the output even though the control signal has been sent out, the CPU circuit determines that the motor is locked, and the fail-safe mode operates. That is, when the motor is locked, the output of the control signal is stopped and the motor control circuit is stopped to prevent damage.

Therefore, as described above, if the CPU circuit operates first and outputs a control signal to the motor drive circuit, but the motor does not operate within a predetermined time, the CP
The U circuit may erroneously recognize this as a motor lock and activate the fail-safe mode. Such a situation may occur not only when the power supply voltage is restored after the power supply voltage is reduced, but also when the voltage is gradually increased from 0V. Then, once the motor stops in the fail-safe mode, there is a problem that the motor cannot be driven until the system is restarted.

For example, when the ignition switch is turned off while the wiper switch is turned on, when the ignition switch is turned on when the engine is started, the CPU circuit is started at the same time, and a control signal is output to the motor drive circuit to start the motor. I do. Then, when the starter motor is driven, a voltage drop occurs with it,
May fall below VMmin. Then, even if the voltage is restored after the engine is started, the fail-safe mode is activated as described above, and the wiper motor may remain stopped.

If the battery is weak, a voltage drop may occur when the air conditioner is turned on, when the headlights are passed, and when the power window is opened and closed. Is assumed. In these cases, the electrical component cannot be used unless the ignition switch is turned off, the wiper switch and the like are turned off, and then the engine is started again, so that the improvement has been desired.

In this case, Japanese Unexamined Patent Publication No. 63-17145 discloses that a signal based on a voltage increase is used as an input signal, and a control signal is sent to a power supply circuit of the electric component, thereby causing a malfunction of the electric component under a low voltage. Is disclosed. However, in the configuration in which the power supply of the electrical components is stopped, the CP
The state in which the electrical component did not respond to the control signal output from the U circuit was not eliminated, and was not effective as a measure against malfunction in the fail-safe mode.

An object of the present invention is to provide a control device capable of driving a vehicle-mounted electric component without erroneously recognizing an operation even when a power supply voltage fluctuates.

[0011]

According to the present invention, there is provided a vehicle electrical equipment control apparatus for controlling an electrical equipment drive circuit for driving an electrical equipment mounted on a vehicle, and controlling the electrical equipment drive circuit. A control circuit that operates at a voltage lower than the minimum operating voltage of the component drive circuit, wherein the control device is a control device for the vehicle-mounted electrical component, wherein power is supplied from a common power supply to the electrical component drive circuit and the control circuit. The control circuit controls an output of a control signal to the electric component driving circuit based on a minimum operating voltage of the electric component driving circuit with respect to a voltage change of the power supply.

According to the present invention, the control signal is output to the electrical component drive circuit based on the minimum operating voltage of the electrical component drive circuit, so that the control signal is accurately transmitted to the electrical component drive circuit in response to a voltage change of the power supply. be able to. Therefore, although the control signal is output when the power supply voltage is lower than the minimum operating voltage, the electric component does not operate, and it is possible to prevent the control circuit from erroneously recognizing this as a malfunction or abnormality of the electric component. For this reason, for example, even in an electrical component in which the fail-safe mode is set at the time of occurrence of an abnormality, it is possible to prevent the fail-safe mode from erroneously operating due to the voltage fluctuation, and to improve the reliability of the system.

In the control device, the control circuit monitors the power supply voltage and recognizes a minimum operating voltage of the electric component driving circuit, and the power supply voltage is lower than a minimum operating voltage of the electric component driving circuit. In this case, the output of the control signal to the electrical component drive circuit may be stopped. As a result, when the power supply voltage is lower than the minimum operating voltage of the electrical component drive circuit, the control signal is not output, so that
It is possible to more reliably prevent erroneous recognition due to no response to electrical components.

Further, in the control device, the control circuit stops outputting a control signal to the electric component driving circuit when the power supply voltage decreases and becomes lower than the minimum operating voltage of the electric component driving circuit, When the power supply voltage is lower than the minimum operating voltage of the control circuit, while stopping its own operation, the power supply voltage is equal to or higher than the minimum operating voltage of the control circuit and starts operating itself. Alternatively, the output of the control signal to the electric component drive circuit may be stopped until the voltage becomes equal to or higher than the minimum operating voltage of the electric component drive circuit. Thus, even if the control circuit is first restored when the power supply voltage drops and rises again, no control signal is output if the power supply voltage is lower than the minimum operating voltage of the electrical component drive circuit. Therefore, for example, even when the power supply voltage temporarily drops due to the start of the starter motor, it is possible to reliably prevent erroneous recognition due to no response of the electrical component.

In addition, in the control device, the electric component may be a wiper motor for driving a wiper device. Thus, for example, even when the ignition switch is turned off with the wiper switch turned on, the control device does not malfunction when the ignition switch is turned on next time, and the fail-safe mode does not operate. Therefore, complicated work such as restarting the system is not required, and unnecessary burden on the driver can be reduced.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a system configuration in a wiper motor (vehicle electrical component) control device according to an embodiment of the present invention, and FIG. 2 shows an operation of a CPU circuit when a power supply voltage fluctuates in the control device in FIG. FIG.

A wiper motor control device (hereinafter, abbreviated as a control device) 1 of the present embodiment is a controller for controlling the drive of a wiper device installed on a windshield of an automobile. The wiper device is configured such that wiper blades respectively disposed on the driver's seat side and the passenger's seat side are driven by one wiper motor (hereinafter abbreviated as motor) 2 via a link mechanism (not shown). . Motor 2
Is controlled by the controller 1, whereby the wiper blade performs a reciprocating wiping operation on the windshield.

The control device 1 has a built-in microcomputer and a CPU circuit (control circuit) 3 which plays a central role in control operation.
And a motor drive circuit (electrical component drive circuit) 4 for driving the motor 2. Power is input to the CPU circuit 3 from the vehicle-mounted battery 5 via the power supply circuit 6.
Its ON / OFF is controlled by an ignition switch 8 connected via an ignition switch input circuit 7. The CPU circuit 3 is connected to a wiper switch 10 via a wiper switch input circuit 9. The wiper switch 10 is provided with mist and window wash switches in addition to the LO, HI, and INT operation positions.

The motor 2 is housed in a motor unit 11, and a relative position signal (rotation signal) indicating a moving amount of the wiper blade in proportion to the motor rotation angle is received from the unit 11.
Also, an absolute position signal indicating the blade position is output. In this case, the motor unit 11 is provided with an A-phase Hall IC circuit 12, a B-phase Hall IC circuit (hereinafter abbreviated as IC circuits) 13, and a fixed-position stopping device 14. Then, relative position signals are output from the IC circuits 12 and 13, and an absolute position signal (origin signal) is output from the fixed position stop device 14. That is, the number of pulses proportional to the rotation angle of the motor is output from the IC circuits 12 and 13,
CPU circuit 3 via motor pulse input circuits 15 and 16
Is input to If the origin is set at the lower inversion position, for example, the home position stop device 14 outputs an origin signal when the blade comes to the lower inversion position and inputs the origin signal to the CPU circuit 3 via the origin input circuit 17. Based on these signals, the CPU circuit 3 calculates the position and the moving speed of the blade, and outputs a control signal to the motor drive circuit 4 as appropriate.

The motor drive circuit 4 controls the rotation speed and direction of the motor 2 based on instructions from the CPU circuit 3. A motor drive FET circuit 18 is provided at a subsequent stage of the motor drive circuit 4 to perform forward / reverse rotation and speed control of the motor 2 to realize a reciprocating wiping operation of the wiper blade. In addition, there is Lo between the CPU circuit 3 and the motor 2.
An / Hi output switching circuit 19 is interposed, and adjusts the output of the motor 2 according to the operation mode selected by the wiper switch 10.

Next, the operation of the control device 1 will be described. As shown in FIG. 2, also in this case, the CPU circuit 3 and the motor drive circuit 4 have the minimum operating voltages VCmin and VMm.
in is defined. Then, the power supply voltage drops and VMmin
If it is less than the above, the motor drive circuit 4 stops and the motor 2 also stops. At this time, since the power supply voltage is still higher than VCmin, the operation state of the CPU circuit 3 is maintained.

However, if the control signal continues to be output as it is and the motor stop time exceeds a predetermined time, the fail-safe mode may operate. Therefore, in the control device 1, when the power supply voltage becomes lower than VMmin, CP
The output of the control signal is stopped even when the U circuit 3 is operating. That is, until the power supply voltage becomes less than VCmin (T
s ₁ ) is the control output stop mode, in which the control output to the motor drive circuit 4 is stopped. This prevents the CPU circuit 3 from erroneously recognizing that the motor is locked, and prevents the fail-safe mode operation.

Thereafter, when the power supply voltage continues to decrease and becomes less than VCmin, the CPU circuit 3 also stops operating. At this time, the output of the control signal to the motor drive circuit 4 has already been stopped, and the system is in a halt state. As a configuration for maintaining the operation of the CPU circuit even under low voltage and preventing the CPU circuit from being initialized, a configuration for lowering the frequency of the system clock under low voltage is described in Utility Model Registration No. 2586696. It is shown.

On the other hand, when the power supply voltage gradually recovers and becomes VCmin or more, first, the CPU circuit 3 returns. Here, the conventional control circuit sends a control signal to the motor drive circuit 4 at this time. If the motor 2 does not operate within a certain time after the output of the control signal, the CPU circuit 3 erroneously recognizes that the motor is locked and the fail-safe mode is activated. The CPU at the time of return
As a measure for preventing malfunction of the circuit itself, Japanese Patent Application Laid-Open No. 61-42001 discloses a configuration in which the circuit is restored after a predetermined time delay from voltage recovery.

On the other hand, in the control device 1 according to the present invention,
At this point, the CPU circuit 3 itself is revived,
If the power supply voltage has not reached the minimum operating voltage VMmin of the motor drive circuit 4, the output of the control signal is stopped. That is, the CPU circuit 3 monitors the power supply voltage, recognizes the minimum operating voltage of the other electrical component to which the control signal is to be transmitted, and stops outputting the control signal when the power supply voltage is lower than that. Then, when the power supply voltage becomes equal to or higher than VMmin, the control signal is output to the motor drive circuit 4 again. That is, the CPU circuit 3 operates between the time when the power supply voltage exceeds VCmin and the operation is restored and the time when the power supply voltage becomes VMmin or more (T
s ₂ ) is the control output stop mode and the motor drive circuit 4
Waits without outputting a control signal for.

After the voltage recovery, the motor drive circuit 4 which has received the control signal from the CPU circuit 3 operates since the power supply voltage has already exceeded VMmin and drives the motor 2 upon receiving the control signal. On the other hand, the CPU circuit 3 recognizes that the motor 2 has been operated by receiving the relative position signal from the motor unit 11 in response to the control signal output. in this case,
Since the motor 2 is immediately activated by the signal output of the CPU circuit 3, the CPU 2 starts the motor 2 without determining that the motor is locked. Therefore, even when the power supply voltage drops due to the starter motor start or the like, the CPU circuit 3 does not erroneously recognize that the motor is locked, and the operation in the fail-safe mode can be prevented. Therefore, complicated work such as restarting the system is not required, and the reliability of the system can be improved.

The present invention is not limited to the above embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the operation of the control device 1 in the case where the power supply voltage drops and then returns and rises has been described. However, the same operation is performed when the power is newly turned on. In the above-described embodiment, the control device for controlling the drive of the wiper device among the in-vehicle electrical components has been described. It is. Further, the vehicle to which the present invention is applied is applicable not only to a vehicle equipped with an internal combustion engine, but also to an electric vehicle, a vehicle using both an internal combustion engine and an electric motor, and the like.

In the above-described embodiment, the case where the present invention is applied to the wiper device in which the wiper blades on the driver's seat side and the passenger's seat side are driven by one motor 2 has been described. The present invention is also applicable to a wiper device of a type in which the wiper blades are individually driven by two motors arranged on each wiper blade.

[0029]

According to the control device for on-vehicle electrical components of the present invention, the control circuit outputs a control signal based on the minimum operating voltage of the electrical component drive circuit in response to a voltage fluctuation of the power supply.
A control signal can be accurately sent to the electrical component drive circuit according to the voltage fluctuation. Therefore, although the control signal is output, the electric component does not operate because the power supply voltage is lower than the minimum operating voltage of the electric component driving circuit, and the control circuit erroneously recognizes this as a malfunction or abnormality of the electric component. Can be prevented. For this reason, it is possible to prevent the fail-safe mode from erroneously operating due to the voltage fluctuation, and to improve the reliability of the system.

When the power supply voltage is lower than the minimum operating voltage of the electric component driving circuit, the output of the control signal to the electric component driving circuit is stopped. In this case, the control signal is not output and the electric component is not output. Erroneous recognition of the control circuit due to no response can be more reliably prevented.

Further, the output of the control signal is stopped when the power supply voltage drops and becomes lower than the minimum operating voltage of the electrical component driving circuit, and the control circuit is turned off when the power supply voltage becomes lower than the minimum operating voltage of the control circuit. Even if the power supply voltage becomes equal to or higher than the minimum operating voltage of the control circuit and the control circuit starts operating, the output of the control signal is stopped until the power supply voltage becomes equal to or higher than the minimum operating voltage of the electrical component drive circuit. With this configuration, even if the control circuit returns to the initial state when the power supply voltage drops and then rises again, no control signal is output if the power supply voltage is lower than the minimum operating voltage of the electrical component drive circuit. Therefore, for example, even when the power supply voltage temporarily drops due to the start of the starter motor, erroneous recognition of the control circuit due to no response to the electrical component can be reliably prevented.

In addition, when the present invention is applied to a wiper device and the wiper motor is used as an electrical component to be controlled, for example, even if the ignition switch is turned off while the wiper switch is turned on, the next time the ignition switch is turned on When the switch is turned on, the control device does not malfunction and the fail-safe mode does not operate. Therefore, complicated work such as restarting the system is not required, and unnecessary burden on the driver can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a wiper motor control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an operation of a CPU circuit when a power supply voltage fluctuates in the control device of FIG. 1;

FIG. 3 is an explanatory diagram showing an operation of a CPU circuit when a power supply voltage fluctuates in a control system of a conventional wiper device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wiper motor control device 2 wiper motor (vehicle electrical component) 3 CPU circuit (control circuit) 4 motor drive circuit (electric component drive circuit) 5 vehicle battery 6 power supply circuit 7 ignition switch input circuit 8 ignition switch 9 wiper switch input circuit 10 wiper switch Reference Signs List 11 Motor unit 12 A phase Hall IC circuit 13 B phase Hall IC circuit 14 Fixed position stop device 15 Motor pulse input circuit (A phase) 16 Motor pulse input circuit (B phase) 17 Origin input circuit 18 Motor drive FET circuit 19 Lo / Hi output switching circuit VCmin Minimum operating voltage of CPU circuit VMmin Minimum operating voltage of motor drive circuit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toru Furusawa 1-2681, Hirosawa-cho, Kiryu-shi, Gunma F-term in Mitsuba Co., Ltd. 3D025 AG79

Claims (4)

[Claims] 1. An electric component driving circuit for driving electric components mounted on a vehicle, and controls the electric component driving circuit, and operates at a voltage lower than a minimum operating voltage of the electric component driving circuit. A control device for an on-vehicle electrical component having a control circuit, wherein power is supplied from a common power source to the electrical component drive circuit and the control circuit, wherein the control circuit responds to a voltage change of the power source. A control device for an in-vehicle electrical component, comprising: controlling a control signal output to the electrical component drive circuit based on a minimum operating voltage of the electrical component drive circuit. 2. The control device according to claim 1, wherein the control circuit monitors the power supply voltage and recognizes a minimum operating voltage of the electric component drive circuit, and the power supply voltage is controlled by the electric device. When the voltage is lower than the minimum operating voltage of the component drive circuit, output of the control signal to the electrical component drive circuit is stopped. 3. The on-vehicle electrical component control device according to claim 2, wherein the control circuit controls the electrical component drive circuit when the power supply voltage decreases and becomes lower than a minimum operating voltage of the electrical component drive circuit. While stopping the output of the control signal, if the power supply voltage becomes lower than the minimum operation voltage of the control circuit, the operation of the control circuit itself is stopped, while the power supply voltage becomes equal to or higher than the minimum operation voltage of the control circuit. A control device for a vehicle-mounted electrical component, characterized in that even when the device starts operating, the output of the control signal to the electrical component drive circuit is stopped until the operating voltage of the electrical component drive circuit becomes equal to or higher than the minimum operating voltage. 4. The control device according to claim 1, wherein said electric component is a wiper motor for driving a wiper device.