JP3337805B2 - Alternator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling an object to be controlled such as an alternator, the engine having a function of suppressing the abnormal state by changing a control amount when an abnormal state such as an overvoltage state occurs. The present invention relates to a control device.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for suppressing an abnormal state by changing a control amount when an abnormal state such as an overvoltage state occurs during control of a control target object, for example, Japanese Patent Laid-Open No. 55-15794
2. Description of the Related Art An alternator control device as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2 is known. This control device provides a control circuit for controlling the amount of power generated by the alternator in accordance with the battery voltage with respect to the alternator including a field coil, a stator coil, a rectifier, and the like. A circuit for stopping energization of the field coil when an overvoltage state higher than a predetermined value is provided.

By the way, in the device disclosed in the above publication,
Although the control circuit is configured by an electric circuit composed of a transistor or the like, in order to perform more advanced control, a control device that controls a control target using a control unit having a CPU is also generally known. In the control of (1), there is a control in which energization of the field coil is performed by duty control or the like in the control unit. In the case of such a control device, when the alternator is in an overvoltage state, by changing the control amount such that the duty control value is set to 0, the energization to the field coil is stopped and the overvoltage state is suppressed.

[0004]

By the way, in an apparatus in which a control object having a CPU is used to control an object to be controlled as described above, when the control amount is changed when an abnormal state such as an overvoltage state occurs. However, there remains a problem that a delay occurs until the abnormal state is suppressed by the change of the control amount.

The control unit controls the power generation amount of the alternator in accordance with the battery voltage and the like. In the control unit, a process of setting and outputting a control amount such as a duty control value is a constant control. This control cycle is performed every cycle. If the control cycle is short, the load on the control unit increases. Therefore, the control cycle is set relatively long within a range that satisfies the control accuracy.
Degree. However, when an overvoltage condition occurs,
If the process of changing and outputting the control amount is also performed at a relatively long cycle similar to the control at the normal time, a considerable delay occurs until the overvoltage state is suppressed by the change of the control amount. Since the alternator output voltage rises sharply when an overvoltage occurs due to a disconnection or the like, the alternator output voltage rises significantly during the delay, adversely affecting the voltage detector and the like receiving this voltage.

The present invention has been made in view of the above circumstances, and has been described in the art in which normally, the control amount is set for a control target and output processing is performed at a relatively long cycle in order to reduce the load on the control unit. It is an object of the present invention to provide an engine control device capable of suppressing the occurrence of a state promptly and improving reliability.

[0007]

Means for Solving the Problems The invention according to claim 1
Controls the alternator power generation according to various conditions
Control amount setting for setting the control amount for each predetermined normal control cycle
And a control signal corresponding to the control amount.
Control means for outputting to the controller
Detects the output voltage of the alternator and
When an overvoltage condition that is higher than the
When the overvoltage state is determined by the determining means and the determining means,
Control amount change to change the control amount in the direction to lower the output voltage
Control means and the control amount changed by the control amount changing means.
Is shorter than the above-mentioned control cycle for normal use.
Control cycle changing means for outputting to the alternator in a cycle.
The alternator control device, wherein the control means comprises:
Corresponds to the control amount set for each of the above normal control cycles
The control signal is sent to a timer card with a predetermined cycle.
Output to the alternator after a predetermined time
The control cycle changing means is shorter than the normal control cycle.
Control signal corresponding to the control amount set in
Control amount without time delay to the amount setting timing
Output to the alternator in accordance with the
You.

[0008] The invention according to claim 2 provides the invention according to claim 1.
In the alternator control device, the
When the voltage state is determined, the output voltage is reduced.
The control amount to be changed to
And the timer counter is reset.
Delays the control amount setting timing
Control signal according to the control amount setting
Is output to the data.

[0009]

According to the first aspect of the present invention, the control means
Is the above control The control set for each of the above normal control cycles
The control signal corresponding to the quantity is
With a predetermined delay by the timer counter
Output to the control alternator.
Set the output and process the output in a relatively long cycle.
Reduce the burden on the troll unit. In addition, the detection
If the stage determines that an overvoltage condition has occurred, the output voltage is reduced.
The control amount to change in the direction is shorter than the control cycle for normal operation.
Set at a constant cycle, and
Output to the alternator without time delay
Quickly reduces the alternator output voltage.
It is.

According to the second aspect of the present invention, the determination means
When the overvoltage state is determined by the stage, the output voltage is reduced.
Control amount to change in the direction to be controlled is shorter than the control cycle for normal operation
The timer counter is reset at
By setting, the control amount setting timing
Control signal according to the control amount setting without time delay
Is output to the alternator,
Output voltage can be quickly reduced.

[0011]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of a control device according to an embodiment of the present invention. In this embodiment, an alternator is used as a control object, and the power generation amount is controlled. That is, the apparatus shown in FIG. 1 includes an alternator 2 driven by a crankshaft of an engine 1 and the alternator 2
A control unit 3 for controlling the operation state of the vehicle, a battery 5 for supplying a current to the control unit 3 and an electric load 4 mounted on the vehicle, etc., a main relay 7 which is connected when the ignition key switch 6 is turned on, Warning lamp 8 that lights up when a failure occurs
And

The alternator 2 includes a stator coil 9
, A field coil 10, and a three-phase full-wave rectifier 11. When the rotor core around which the field coil 10 is wound rotates, the AC current generated in the stator coil 9 is applied to the electric load 4 and the battery 5. Is configured to be supplied. Further, the current flowing through the field coil 10 is controlled by the control unit 3, and more specifically, the current is controlled by a duty signal output to a transistor 15 connected to the field coil 10, whereby the alternator 2 Is feedback-controlled.

The control unit 3 includes an intake air temperature detecting means 12 for detecting an intake air temperature of an engine, a vehicle speed detecting means 13 for detecting a running speed of a vehicle, a water temperature detecting means 14 for detecting a cooling water temperature of the engine, and the like. The detection signal is input, and further, the battery voltage Vs and the output voltage Vt of the alternator are input.

As shown in FIG. 2, the control unit 3 includes control amount setting means 16, control means 17, determination means 18, control amount changing means 19, and control cycle changing means 20.
have. The control amount setting means 16 sets a control amount for the alternator 2 according to various conditions. Specifically, as shown in a flowchart described later, the target voltage of the battery set according to the intake air temperature and the like and the actual battery The voltage is compared with a voltage, and the duty control value of the duty signal is set according to the comparison result.

The control means 17 outputs a control signal corresponding to the duty control value set by the control amount setting means 16 via a pulse width modulation means (PWM) 21 and executes this processing for a predetermined normal time. It is performed every control cycle. As described later, the pulse width modulation means 21 generates a duty signal by a pulse wave having a constant period by using a PWM timer, and adjusts the pulse width of the duty signal in accordance with the duty control value. It was done.

The judging means 18 judges when the value of the variable element that changes according to the control amount is in an abnormal state exceeding a predetermined normal range. In this embodiment, the output voltage of the alternator 2 is determined. Vt, and the output voltage Vt
Is determined when an overvoltage state occurs in which the value is higher than a predetermined value (overvoltage determination reference value). This determination means 18
Is set shorter than the normal control cycle.

The control amount changing means 19 changes the control amount in a direction to decrease the output voltage Vt when the overvoltage state is determined. Specifically, the duty control value is set to 0 when the overvoltage state is determined. %. Further, the control cycle changing means 20 outputs the control amount changed by the control amount changing means 19 in a cycle shorter than the normal control cycle. Specifically, the determination means 1
In the same cycle as the processing in step 8, the signal with the duty control value set to 0% is output, and the output of the pulse modulation means 21 is switched off by resetting the counter of the PWM timer.

The control executed in the control unit 3 will be described with reference to the flowcharts shown in FIGS.

FIG. 3 shows a control cycle for normal use (for example, 10 m).
This is a control routine that is performed every s), and the processing as the control amount setting means 16 and the control means 17 is performed by this routine.

When the processing of this routine starts, first, in step S1, the detected value of the battery voltage Vs is input, and then, in step S2, a target voltage Ve for charging the battery 5 is set. The target voltage Ve is set as shown in FIG. 5, for example, according to the intake air temperature corresponding to the battery temperature. That is, when the temperature is low, the charge current receiving performance of the battery is low. Therefore, the target voltage Ve is increased in order to prevent insufficient charging, and when the temperature is high, the charge current receiving performance of the battery is high, so that overcharging is performed. In order to prevent this, the target voltage Ve is lowered.

Next, in step S3, it is determined whether or not the overvoltage identification flag Xv is 0. When it is determined that the overvoltage identification flag Xv is 0 (when not in an overvoltage state)
Performs the processing after step S4.

In step S4, the battery voltage V
s and the set value of the target voltage Ve are compared to determine whether the battery voltage Vs is higher than the target voltage Ve.

If the result of this determination indicates that the battery voltage Vs is higher than the target voltage Ve, it is used in step S5 for duty control of the current value supplied to the field coil 10 of the alternator 2. By subtracting a preset amount dd from the previous duty control value Fd ', a duty control value Fd used for the current duty control is calculated. If NO is determined in step S4 and it is confirmed that the battery voltage Vs is equal to or lower than the target voltage Ve, the process proceeds to step S4.
In step 6, the duty control value Fd used for the current duty control is calculated by adding a predetermined amount dd to the previous duty control value Fd '.

After the calculation in step S5 or step S6, in step S7, the duty control value F
By outputting a control signal corresponding to d, feedback control for making the battery voltage Vs equal to the target voltage Ve is executed, and then the process returns.

When it is determined in step S3 that the overvoltage discrimination flag Xv is 1 (in the case of an overvoltage state), the routine returns as it is, that is, the calculation and output of the duty control amount are not performed in this routine.

FIG. 4 shows a routine which is executed at intervals (for example, 1 ms) shorter than the above-described normal control period. This routine allows the determination means 18, the control amount changing means 19 and the control period changing means 20 to be executed. Is performed.

When the processing of this routine is started, first, the output voltage Vt of the alternator 2 is input in step S11, and in step S12, it is determined whether or not the output voltage Vt is higher than the overvoltage determination reference value A. If this determination is NO, that is, if the output voltage Vt is equal to or less than the overvoltage determination reference value A, the overvoltage identification flag Xv is set to 0 in step S13.

If the determination in step S12 is YES, that is, if the output voltage Vt is higher than the overvoltage determination reference value A, the overvoltage identification flag Xv is set to 1 in step S14, and the duty control is performed in step S15. The value Fd is set to 0. In step S16, a control signal corresponding to the duty control value Fd is output, and the counter of the PWM timer is reset.

According to the control device of the present embodiment as described above, the change of the control signal and the like when the alternator 2 changes from the normal state to the overvoltage state during the control is as shown in the time chart of FIG. The operation will be described with reference to FIG.

The signal a in FIG. 6 is the processing timing according to the routine of FIG. 3 (hereinafter referred to as routine I), and the signal b is the processing timing according to the routine of FIG. 4 (hereinafter referred to as routine II). . These signals a, b
As shown by, the routine I is performed in a relatively long period, that is, a normal control period, and the routine II is performed in a short period. When the output voltage Vt is in a normal range equal to or less than the overvoltage determination reference value A, the calculation of the duty control value Fd and the processing of the control signal output are performed in the routine I having a relatively long cycle. 3 is reduced.

The duty control value Fd calculated in the routine I at the normal time is a value that causes the battery voltage Vs to converge to the target voltage Ve by feedback control. Then, the pulse width modulation means 21 generates the duty control value Fd at a predetermined duty cycle Td.
Is output. That is, in the pulse width modulation means 21, the output TCNT of the PWM timer counter gradually increases from 0 to the upper limit value during the duty cycle Td, and the timer counter output TCNT is set to the duty register value corresponding to the duty control value Fd. The PWM output is turned on until DTR is reached, and when the timer counter output TCNT exceeds the duty register value DTR, the PWM output is turned off. This PWM output becomes a duty signal corresponding to the duty control value Fd.

The power supply to the field coil 10 is controlled by this signal, and the power generation amount of the alternator 2 is controlled so that the battery voltage Vs converges to the target voltage Ve.

The process of inputting the output voltage Vt of the alternator 2 and comparing it with the overvoltage determination reference value A is performed in a short cycle routine II. Thus, when the output voltage Vt is in an overvoltage state higher than the overvoltage determination reference value A, this is quickly determined.

When it is determined that an overvoltage condition has occurred, the duty control value Fd is changed to 0%, so that energization of the field coil is cut off, and the output voltage of the alternator 2 is reduced.

In this case, by changing the duty control value Fd to 0 and outputting the duty control value Fd in the routine II, the control cycle when the overvoltage state is determined is changed so as to be shorter than the normal time. Then, the PWM timer counter is reset. Therefore, as compared with the case where such a change of the control cycle is not performed, the responsiveness of the control at the time of the overvoltage is enhanced, and the action of suppressing the abnormal increase in the output voltage of the alternator 2 is enhanced.

That is, the processing for changing and outputting the duty control value without changing the control cycle is performed in the routine I.
As shown by a two-dot chain line in FIG. 6, a considerable amount of time elapses from the time point t0 when the overvoltage state is reached to the time point t2 when the duty control value is changed at the processing timing of the routine I after the overvoltage state determination. A delay time occurs, and a delay occurs before the duty signal generated at this time t2 is turned off. For this reason, the time T 'from when the overvoltage state occurs to when the energization of the field coil is cut off becomes longer, and during that time, the tendency of the overvoltage increases.

In contrast, according to the present embodiment, as shown by the solid line in FIG. 6, the overvoltage state is determined by the routine II having a short cycle, and the duty control value Fd is changed at the overvoltage state determination time t1. As a result, the delay from the occurrence of the overvoltage state to the change of the duty control value is reduced. In addition, the PWM timer counter is reset at time t1, whereby the PWM output is immediately turned off. Therefore, the time T from the occurrence of the overvoltage state until the energization of the field coil is cut off is greatly reduced, and the output voltage of the alternator is rapidly reduced.

[0039]

According to the first aspect of the present invention, the control amount is
Control means for outputting a corresponding control signal to the alternator
Corresponds to the control amount set for each of the above normal control cycles.
The control signal to
A predetermined time is delayed by the
Output to control the alternator
Setting and output processing at a relatively long cycle,
It is possible to reduce the burden on the rule unit.

An alternator that changes according to the control amount
Detects the output voltage of the
Detection means for determining when a high overvoltage condition has occurred
The output voltage is reduced when it is determined that an overvoltage condition has occurred.
The control amount to be changed in the direction is shorter than the control cycle for normal operation.
Set in the cycle, and further,
Output to the alternator without time delay
Reduces the alternator output voltage quickly
It becomes possible.

Therefore, in the normal state,
Control amount setting and output processing
It should be performed in a relatively long cycle to reduce the burden
However, when an abnormal condition occurs, it is quickly suppressed
And reliability can be improved .

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an entire control device according to a first embodiment.

FIG. 2 is a functional block diagram illustrating a configuration of a control unit in the embodiment.

FIG. 3 is a flowchart showing one routine of control according to the embodiment.

FIG. 4 is a flowchart illustrating another control routine according to the embodiment.

FIG. 5 is a diagram showing a relationship between intake air temperature and a target voltage of a battery.

FIG. 6 is a time chart showing changes in various signals under the control of the embodiment.

[Explanation of symbols]

 2 Alternator 3 Control unit 16 Control amount setting means 17 Control means 18 Judgment means 19 Control amount changing means 20 Control cycle changing means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-184081 (JP, A) JP-A-58-54405 (JP, A) JP-B-46-14925 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) H02J ^7/ 14-7/24 H02P 9/04 H02P 9/30

Claims (2)

(57) [Claims] 1. The amount of power generated by an alternator according to various conditions
Is set for each predetermined normal control cycle.
Control amount setting means for outputting a control signal corresponding to the control amount to the alternator.
Control means, and the output voltage of the alternator, which varies according to the control amount,
Detected, and this output voltage becomes an overvoltage state higher than a predetermined value.
When Tsu, and judging means for judging this, the output voltage is determined overvoltage condition by the determining means
A control amount changing means for changing the control amount in a direction to decrease, and a control amount corresponding to the control amount changed by the control amount changing means.
The control signal is cycled at a cycle shorter than the normal control cycle.
Alternator having control cycle changing means for outputting to the alternator
A discriminator controller, the control means has been set for each of the normal for the time control period
The control signal corresponding to the control amount is
With a predetermined period of time
And the control cycle changing means is shorter than the normal control cycle.
Control signal corresponding to the control amount set in
Control amount without time delay to the amount setting timing
Output to the alternator according to the setting of
Alternator control device. 2. The alternator control device according to claim 1,
When the overvoltage state is determined by the determination means,
The control amount to change in the direction to decrease the output voltage is usually
It is set at a cycle shorter than the time control cycle, and
The control amount is set by resetting the timer counter.
Control amount setting without time delay for fixed timing
That the control signal is output to the alternator
Alternator control device .