JP7330610B2 - vehicle controller - Google Patents

Description

The present invention relates to a vehicle control device comprising a battery for supplying electric power to a plurality of vehicle-mounted electric loads, an alternator for charging the battery by generating electricity from the rotation of an engine, and power generation control means for controlling the power generation of the alternator.

Conventionally, a battery mounted on a vehicle supplies power to various vehicle-mounted electrical loads, and when the charge amount decreases, it is charged by the power generated by the alternator. At this time, based on the integrated value of the battery current detected by the current sensor, the SOC (State Of Charge), which is the ratio of the remaining charge of the battery at that time to the battery charge capacity at full charge, is estimated. However, if it does not fall below the lower limit of the charge control range, for example, 92%, battery charge/discharge control is repeated, and if the estimated SOC falls below 92%, charge/discharge control is generally prohibited to protect the battery. is.

By the way, in this type of device, the amount of charge in the battery due to the power generated by the alternator and the amount of discharge from the battery due to the supply of operating power to the electric load are integrated to calculate the remaining charge of the battery. is stored in a memory, and when the engine is restarted under idling stop control, the remaining charge amount of the battery is accurately calculated by subtracting the discharge amount error considering the power consumption of the starter from the remaining charge amount stored in the memory. has been proposed (see Patent Document 1).

JP 2017-229183 A (paragraphs 0038 to 0047 and FIGS. 3 to 5)

However, as described above, the conventional apparatus may consider the error on the discharging side of the battery but does not consider the error on the charging side of the battery. That is, the battery is normally designed and manufactured by a battery manufacturer such that the true SOC exceeds 100% even if the estimated SOC of the battery is 100% when the battery is new and has not deteriorated at all. Therefore, when the battery is new and not deteriorated, the true SOC is 100% or more than 100%. Due to self-discharge of the battery or the like, it may be calculated to be, for example, 92%, and an error may occur between the estimated SOC and the true SOC.

As a result, the battery is overcharged even though the battery does not need to be charged, leading to deterioration of the battery. Various inconveniences caused by errors on the charging side of the battery occur, such as prohibiting the charging/discharging control of the battery even though the charging/discharging control of is not prohibited.

According to the present invention, if the battery is not degraded and the battery is overcharged by the alternator, the estimated value of the battery charge is corrected to a higher value so that the battery charging/discharging control can be performed according to the actual battery charge. aim.

In order to achieve the above object, the vehicle control device of the present invention comprises a battery that supplies power to a plurality of vehicle-mounted electric loads, and an engine rotation that generates power to charge the battery, and the rotation of the engine during deceleration. A vehicle control device comprising: an alternator for generating power by deceleration regeneration to charge the battery ; and a power generation control means for controlling power generation by increasing the work of the alternator so that the terminal voltage of the battery reaches a target voltage. a charge amount estimating means for estimating the battery charge amount based on an integrated value of the battery current of the battery detected by a current sensor; battery deterioration detection means for detecting the presence or absence of deterioration of the battery based on whether or not there is deterioration; and when the battery deterioration detection means detects that there is no deterioration of the battery, the alternator is operated without deterioration of the battery. determining means for determining whether or not the battery is overcharged by the alternator; and when the determining means determines that the non-deteriorated battery is overcharged by the alternator, the charge amount estimating means determines and correction means for correcting the estimated value of the battery charge amount to a value higher by a predetermined value, wherein the judgment means detects that the battery deterioration detection means has detected that there is no deterioration of the battery, and deceleration regeneration of the alternator is performed. When the terminal voltage of the battery reaches the target voltage before the amount of work of the alternator reaches a predetermined amount in the state of (1), it is determined that the battery is not deteriorated and is in a state of being overcharged by the alternator. is characterized by

According to this invention, when the battery deterioration detection means detects that the battery is not deteriorated and the determination means determines that the non-deteriorated battery is overcharged by the alternator, the charge amount is estimated. Since the estimated value of the battery charge is corrected to a value higher by a predetermined value, the battery is overcharged even though it does not need to be charged, and the battery charge is controlled by charge/discharge control as in the conventional method. It is possible to prevent the battery charge/discharge control from being prohibited even though it is not necessary to prohibit the battery charge/discharge control due to an erroneous judgment that the battery charge/discharge control has decreased to a value that prohibits the actual Battery charge/discharge control can be performed according to the battery charge amount.

1 is a block diagram of one embodiment of a vehicle control device of the present invention; FIG. FIG. 2 is an operation explanatory diagram of FIG. 1; FIG. 2 is an operation explanatory diagram of FIG. 1; FIG. 2 is an operation explanatory diagram of FIG. 1; FIG. 2 is a flowchart for explaining the operation of FIG. 1; FIG.

An embodiment of an idling stop vehicle equipped with a vehicle control device according to the present invention will be described in detail with reference to FIGS. 1 to 5. FIG.

In FIG. 1, reference numeral 1 denotes a vehicle control device mounted on an idling stop vehicle using an engine 2 as a driving source. and a battery 5 that is charged by the power generated by Here, the battery 5 is, for example, a lead battery with a nominal voltage of 12 V. The battery 5 is connected to an electric load 7 such as a wiper motor, a headlight, an air conditioner, and an audio device mounted on an idling stop vehicle. An electrical load 7 is powered from a battery 5 via line 6 .

When the ignition (IG) switch is turned on to start the engine 2 , voltage is applied to the starter 3 from the battery 5 through the power supply line 6 , the plunger of the starter 3 moves, and the starter gear of the starter 3 moves to the position of the engine 2 . It meshes with the flywheel held on the crankshaft. Then, the relay provided in the starter 3 is turned on, the engine 2 is cranked, and the ignition plug of the engine 2 is sparked while the engine 2 is being cranked, thereby starting the engine 2 .

The alternator 4 includes a rotor, a stator, and an IC regulator. The rotor rotates as the crankshaft of the engine 2 rotates, and a rotor coil provided on the rotor rotates. By supplying the excitation current, a three-phase alternating current flows through the stator coils provided in the stator by electromagnetic induction. This three-phase alternating current is rectified into a DC voltage by a rectifier, and DC power is output from the alternator 4 as generated power. be.

At this time, the IC regulator of the alternator 4 controls the duty ratio of the exciting current supplied to the rotor coil. The amount of power generated by the alternator 4 decreases as the time increases. The alternator 4 also has a deceleration regeneration function that regenerates power from the rotation of the engine during deceleration to charge the battery 5 and suppresses power generation by the engine to reduce fuel consumption.

Furthermore, the idling stop car is provided with a plurality of ECUs (Electronic Control Units) having a microcomputer configuration including a CPU and a memory, and each ECU is configured so that two-way communication is performed by CAN (Controller Area Network) communication. It's becoming These ECUs include an ECU 8 shown in FIG. An engine speed sensor that outputs a pulse signal synchronized with rotation as a detection signal, a throttle opening sensor that outputs a detection signal corresponding to the opening of the electronic throttle valve of the engine 2 (throttle opening), and a terminal voltage of the battery 5 Various sensors such as a voltage sensor for detection, a current sensor for detecting the current of the battery 5, and a temperature sensor for measuring the ambient temperature of the battery 5 are connected. Further, the ECU 8 is also powered by the battery 5 . The ECU 8 has a function of calculating and estimating the battery charge amount based on the integrated value of the battery current of the battery 5 detected by the current sensor, and this function corresponds to the "charge amount estimating means" in the present invention. .

Based on information obtained from detection signals of various sensors and various information input from other ECUs, the ECU 8 controls the electronic throttle valve and injectors of the engine 2 for starting, stopping, adjusting the output, etc. of the engine 2. and controls spark plugs, etc. Further, the ECU 8 sets a target voltage, which is a target value of the battery voltage, generates a voltage adjustment signal based on the difference between the target voltage and the battery voltage, outputs the voltage adjustment signal to the IC regulator of the alternator 4, When the voltage adjustment signal is input to the IC regulator, the IC regulator controls the duty ratio of the excitation current of the alternator 4 based on the voltage adjustment signal. Such a control function of the alternator 4 by the ECU 8 corresponds to the "power generation control means" in the present invention.

Further, the ECU 8 automatically stops the engine 2 when a predetermined engine stop condition is satisfied during running, and restarts the engine 2 by the starter 3 when a predetermined engine restart condition is satisfied while the engine 2 is automatically stopped. It has a stop control function. It should be noted that the control of the engine 2 and the idling stop control described above are not limited to being controlled by the ECU 8 alone, and may be controlled by different ECUs.

By the way, to explain the idling stop control operation of the idling stop vehicle, when the driver gets in the vehicle and turns on the ignition (IG) switch (not shown) to command the engine start, the IG switch signal is input to the ECU 8. Based on this input, the relay of the starter 3 is instantaneously energized and turned on by the ECU 8, power is supplied from the battery 5 to the starter 3, the starter 3 is started, and the stopped engine 2 is started (initial start). Once the engine 2 is started and the battery 5 is once charged to a fully charged state by the electric power generated by the alternator 4, the idling stop control is executed by the ECU 8 until the engine 2 is stopped by turning off the IG switch. .

When the ECU 8 during idling stop control detects that the driver depresses the brake pedal according to a red traffic light, for example, and the master cylinder pressure is equal to or higher than a predetermined depression pressure, the ECU 8 detects various sensors. When it is confirmed that a predetermined stop condition for idling stop control (for example, the condition that the stop lamp is lit and the vehicle speed is below a predetermined speed) is established based on the signal from When the vehicle speed also drops below a predetermined vehicle speed, the fuel throttle to the engine 2 is throttled and the engine 2 is automatically stopped.

On the other hand, when the ECU 8 detects that the driver has taken his foot off the brake pedal as the traffic light turns green and the master cylinder pressure has decreased to a predetermined release pressure, the ECU 8 causes the idling stop vehicle 1 to stop idling. When it is confirmed that a predetermined restart condition (for example, the stop lamp is off and the door is closed) is established, the relay of the starter 3 is instantaneously energized based on the restart command from the ECU 8. is turned on, power is supplied from the battery 5 to the starter 3, the starter 3 is started, and the stopped engine 2 is automatically restarted. Thereafter, the automatic stop of the engine 2 based on the establishment of a predetermined stop condition during deceleration and the automatic restart of the engine 2 based on the establishment of a predetermined restart condition are alternately performed.

By the way, the SOC (corresponding to the "battery charge amount" of the present invention), which is the ratio of the remaining charge of the battery at that time to the battery charge capacity at full charge, can be calculated based on the integrated value of the battery current. Normally, the battery 5 is designed and manufactured by the battery maker so that the actual SOC exceeds 100%. It exceeds 100% as indicated by the dashed-dotted line in the middle. Therefore, as shown by the solid line in FIG. 2, if the battery 5 is not new and is deteriorated, even if the estimated SOC is discharged from 100% to, for example, 98%, the battery 5 will not deteriorate. does not fall below 100%, the battery 5 is not overcharged without deterioration, or the SOC of the battery 5 has not decreased to a level that prohibits charge/discharge control. Even though it is erroneously determined that the control has been lowered to the level that prohibits control, or the SOC of the battery 5 has not decreased to the idle stop prohibition level that is lower than the level that prohibits charge/discharge control, the idle stop prohibition level is estimated. It is erroneously determined that the SOC is low, and idling stop is prohibited.

Therefore, in order to prevent such inconvenience, the ECU 8 performs the following control. That is, the ECU 8 estimates the battery state of charge (SOC) based on the integrated value of the battery current of the battery 5 detected by the current sensor, and the minimum value of the terminal voltage of the battery 5 when the ignition switch is turned on is within a predetermined range. The presence or absence of deterioration of the battery 5 is detected based on whether it is equal to or less than the threshold value, and when it is detected that the battery 5 is not deteriorated, the battery 5 is not deteriorated and is in a state of being overcharged by the alternator 4. When it is determined that the non-degraded battery 5 is in a state of being overcharged by the alternator 4, the estimated SOC, which is the remaining charge of the battery, increases by a predetermined correction value set in advance. corrected. Here, the process of detecting the presence or absence of deterioration of the battery 5 by the ECU 8 corresponds to "battery deterioration detection means" in the present invention, and the correction process of the estimated SOC by the ECU 8 corresponds to the "correction means" of the present invention.

The presence or absence of deterioration of the battery 5 is detected by the following procedure. When the ignition switch is turned on, the terminal voltage of the battery 5 drops abruptly, for example, as shown in FIG. Since the voltage rises to a predetermined voltage along with it, depending on whether both the minimum voltage V1 during rushing immediately after the ignition switch is turned on and the minimum voltage V2 during cranking fall below preset threshold values V1t and V2t, respectively, the battery life is determined. 5 deterioration is determined. Both the minimum voltage V1 during rushing and the minimum voltage V2 during cranking of the battery 5 do not fall below the respective threshold values V1t and V2t (V1>V1t, V2>V2t), which continues five times, for example. Then, the ECU 8 detects that the battery 5 has not deteriorated.

Whether or not the battery 5 is not degraded and is overcharged by the alternator 4 is determined by the ECU 8 depending on whether or not the following conditions are satisfied.

(1) Deceleration regenerative state The ECU 8 determines that the deceleration regenerative state is in effect when the accelerator pedal is not depressed and the lockup clutch is ON.

(2) Battery Fluid Temperature is Higher than 15° C. The ECU 8 determines whether the battery fluid temperature estimated from the ambient temperature of the battery 5 by the temperature sensor is higher than 15° C. at which the battery's original performance can be maintained.

(3) The work load (FDUTY) of the alternator 4 is less than 50% As shown in FIG. When the target voltage rises from 14.5 V to 16 V, for example, as shown in FIG. A regenerated charging current flows, and the terminal voltage of the battery 5 gradually rises as shown in FIG. At this time, when the battery 5 is degraded, the FDUTY of the alternator 4 increases to 100%. By the time the FDUTY of the alternator 4 reaches 50%, for example, the terminal voltage of the battery 5 reaches 16 V, which is the target voltage. It is determined whether the FDUTY of the alternator 4 is less than 50% when the terminal voltage of the battery 5 during deceleration regeneration reaches the target voltage.

(4) Estimated SOC is less than 92% The estimated SOC of the battery 5 calculated from the integrated value of the battery current is less than, for example, 92%, which is preset as a level at which charge/discharge control of the battery 5 should be prohibited. It is judged whether

Then, the ECU 8 determines that all of the above conditions (1) to (4) are satisfied, that is, in the deceleration regeneration state, the battery fluid temperature is higher than 15° C., and the work load (FDUTY) of the alternator 4 is less than 50%. When the estimated SOC of the battery 5 at that time is less than 92%, it is determined that the battery 5 is new and not deteriorated and is in an overcharged state. is in a state of being overcharged by the alternator 4, the estimated SOC, which is used as the criterion for determining the condition in (4) above, is reduced by the correction amount δ (such as 3%) obtained experimentally in advance. The estimated SOC of 92% is corrected to, for example, 95%.

The control operation of the ECU 8 will be described with reference to the flowchart of FIG. It is determined whether or not the battery 5 is degraded (step S1) based on whether the respective threshold values are exceeded, and if the battery 5 is degraded and the determination result is NO, the operation is terminated If the determination result is YES, that is, if the battery 5 has not deteriorated, the battery 5 is new and not deteriorated and is overcharged based on whether or not all of the above conditions (1) to (4) are satisfied. If the determination result is NO, the operation is terminated. If the determination result is YES, the estimated SOC calculated based on the integrated value of the battery current is set to The correction amount .delta. is added and corrected (step S3) .

Therefore, according to the above-described embodiment, when the ECU 8 detects that the battery 5 is not degraded and determines that the battery 5 that is not degraded is overcharged by the alternator 4, the battery is charged. Since the estimated value of the amount is corrected to a value higher by a predetermined value, the battery 5 is overcharged even though the battery 5 does not need to be charged, or the battery charge amount prohibits charging/discharging control as in the conventional art. is erroneously determined to have decreased to a value where the charging/discharging control of the battery 5 is prohibited even though the value does not require prohibiting the charging/discharging control of the battery 5, or the level at which the charging/discharging control is prohibited. Even though the SOC of the battery 5 has not decreased to the idle stop prohibition level lower than the idling stop prohibition level, it is prevented from erroneously determining that the estimated SOC has decreased to the idle stop prohibition level and idling stop is prohibited. It is possible to perform charge/discharge control of the battery 5 according to the actual battery charge amount.

Further, as described above, in the deceleration regeneration state, the battery liquid temperature is higher than 15° C., the work (FDUTY) of the alternator 4 is less than 50%, and the estimated SOC of the battery 5 at that time is 92%. In order to determine whether the battery 5 is in an overcharged state when the FDUTY is less than 50%, especially in the state of deceleration regeneration, whether the alternator 4 is working, that is, whether the FDUTY of the alternator 4 is less than 50%, for example. It is easy to see, and it is possible to easily and reliably determine whether or not the battery 5 is in an overcharged state.

The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the level at which the charge/discharge control of the battery 5 should be prohibited is set when the estimated SOC falls below 92%, but it is not limited to 92%. Furthermore, although 3% was exemplified as the correction amount δ of the estimated SOC, the correction amount is not limited to 3%, and the correction amount may be an optimum numerical value obtained experimentally in advance.

In addition, as a condition for determining whether the battery 5 is not degraded and is overcharged by the alternator 4, the work load (FDUTY) of the alternator 4 is less than 50%, but 50% is not an example. However, it is not necessarily limited to less than 50%.

Further, in the above-described embodiment, the case where the present invention is applied to the idling stop vehicle 1 has been described, but the present invention can also be applied to a vehicle such as the idling stop vehicle Iga.

The present invention is applied to a vehicle control device comprising a battery for supplying electric power to a plurality of on-vehicle electrical loads, an alternator for charging the battery by generating electricity from the rotation of the engine, and power generation control means for controlling the power generation of the alternator. be able to.

REFERENCE SIGNS LIST 1 vehicle control device 2 engine 4 alternator 5 battery 8 ECU (power generation control means, charge amount estimation means, battery deterioration detection means, correction means)

Claims (1)

a battery that supplies power to a plurality of in-vehicle electrical loads; an alternator that generates power when the engine rotates to charge the battery and generates power through deceleration regeneration when the engine rotates during deceleration to charge the battery; and the battery. A vehicle control device comprising power generation control means for performing power generation control by increasing the work load of the alternator so that the terminal voltage of becomes the target voltage ,
a charge amount estimating means for estimating a battery charge amount based on an integrated value of the battery current of the battery detected by a current sensor;
battery deterioration detection means for detecting the presence or absence of deterioration of the battery based on whether or not the minimum value of the terminal voltage of the battery when the ignition switch is turned on is equal to or less than a predetermined threshold;
determination means for determining whether or not the battery is not degraded and is overcharged by the alternator when the battery degradation detection means detects that the battery is not degraded;
When the determining means determines that the non-degraded battery is overcharged by the alternator, the estimated value of the battery charge amount by the charge amount estimating means is corrected to a value higher by a predetermined value. compensating means ,
The determination means detects that there is no deterioration of the battery by the battery deterioration detection means, and the terminal voltage of the battery increases until the amount of work of the alternator reaches a predetermined amount in the state of deceleration regeneration of the alternator. A vehicle control device , wherein when the target voltage is reached, it is determined that the battery is not deteriorated and is overcharged by the alternator .

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