JP6725399B2 - Electronic control unit for automobile - Google Patents

Description

The present invention relates to a vehicle electronic control device that controls an idle speed by estimating an electric load from a power consumption of a vehicle.

Along with the reduction in engine idle speed, there has been proposed a technique for controlling the idle speed according to an electric load, which is one of the loads during idling. For example, in Patent Document 1, when the engine is in an idle state and the current consumption of the vehicle can be supplied from a battery, the target power generation voltage of the vehicle generator is set to a voltage lower than usual to set the non-power generation state, A control device for a vehicle generator is disclosed that issues an increase command for the intake air amount when an increase in the electric load is detected, and can respond to an increase in the load accompanying the start of power generation of the vehicle generator by increasing the air amount. There is.

JP, 2009-024668, A

By the way, the current consumption of a vehicle can be basically estimated on the vehicle side from the operating states of various kinds of equipment mounted therein. The electric loads that can be detected by the vehicle include headlights, hazard lamps, air conditioners, navigation systems, audios, and the like.
However, the user may not be able to recognize the amount of electricity used by a cigarette lighter or an outlet. In particular, when a plurality of devices are connected to a cigarette lighter or an outlet with so-called octopus wiring, it becomes difficult to estimate the current consumption. In order to detect the deterioration of the battery, the current consumption can be measured when the current sensor is connected to the negative terminal of the battery, but the measurement is difficult if the user directly connects the battery to the electric load. is there.

Therefore, there is a possibility that the engine rotation becomes unstable due to the power generation load accompanying the increase of the load, or the battery is over-discharged and stalled. This problem can be avoided by carrying out load handling with a margin, that is, by increasing the idle speed to increase the amount of power generation, but this is contrary to the reduction in idle speed and increases fuel consumption.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the idle stability of the engine and to cause the battery to be over-discharged without causing an unnecessary increase in fuel consumption. An object of the present invention is to provide an electronic control device for an automobile capable of suppressing the above-mentioned problem.

The electronic control unit for an automobile of the present invention is an electric load estimating unit that estimates an electric load from the electric power consumption of the vehicle, and an electric power generation amount of an alternator whose engine is idle according to the electric load estimated by the electric load estimating unit. And a power generation amount setting means for setting, detecting the discharge amount of the battery during idling, and the power generation amount of the alternator set by the power generation amount setting means, the discharge amount of the electric load discharging the battery. An electronic control unit for a vehicle, which corrects according to the above, when estimating the peak value of the regeneration amount when performing the regenerative power generation in the deceleration state of the vehicle, the peak current of the regeneration amount falls below the set threshold value. If it is, it is determined that there is an unknown electric load that the vehicle does not recognize , the power consumption is estimated in the subsequent idle state, and the It is characterized in that the power generation amount of the alternator is corrected.

According to the present invention, the existence of an unknown load is confirmed from the electric power consumption of the vehicle, the electric power consumption is estimated in the idle state, and the electric power generation at the time of idling is calculated according to the electric power generation combined with this electric power consumption. Since the correction is performed, the idle stability of the engine can be improved and the battery can be prevented from being over-discharged. Further, since the amount of power generation required during idling is set according to the electric load, useless fuel consumption can be suppressed.

It is a block diagram showing a schematic structure of an electronic control unit for vehicles concerning an embodiment of the present invention. 3 is a flowchart showing the operation of the electronic control device shown in FIG. 1. 3 is a timing chart for explaining the operation of the electronic control unit shown in FIG. 1 and showing changes in a vehicle speed, a target equivalence ratio, a battery voltage, and a charge/discharge current of the battery. It is a wave form diagram which shows the relationship between the discharge amount of the battery detected with the current sensor, and the 1st thru|or 3rd threshold value. It is a wave form diagram which shows the relationship between the amount of regeneration to a battery, and discharge current.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a vehicle electronic control device according to an embodiment of the present invention. An ECU (Electronic Control Unit) 1 as an electronic control device for a vehicle is configured to include a microcomputer 2, an input circuit 3, an output circuit/output monitoring circuit 4, a power supply circuit 5, and the like. Then, the ECU 1 controls various control devices 15 of the engine 14.

The input circuit 3 includes various sensors and switches provided in the engine 14, such as an engine rotation sensor, a crank angle sensor, a water temperature sensor, or an ignition key, a starter switch, a throttle sensor, and the like provided in the vehicle, for measuring results and switches. A signal indicating the state is input. Further, a signal indicating current consumption is input from the current sensor 13 that measures the current consumption of the battery 12.

The signal input to the input circuit 3 is input to the microcomputer 2, and the signal processed by the microcomputer 2 is supplied from the output circuit to the relays and solenoid valves of various control devices 15 provided in the engine 14, For example, ignition timing, fuel injection amount, opening/closing of a throttle valve, valve timing, etc. are controlled. At this time, the output monitor circuit feeds back the control states of the various control devices 15 to the microcomputer 2, and the microcomputer 2 monitors the control states of the various control devices 15.
Further, the voltage Vba is applied to the power supply circuit 5 from the battery 12, and the operating power is supplied to each circuit, for example, the microcomputer 2, the input circuit 3, and the output circuit/output monitoring circuit 4.

The microcomputer 2 includes a CPU (Central Processing Unit) 6, an A/D converter (ADC) 7, a D/A converter (DAC) 8, a random access memory (RAM) 9, a read-only memory (ROM) 10 or a flash. A nonvolatile memory such as an EEPROM is built in, and these are connected to each other via a bus 11. The CPU 6 is one of the central components of the microcomputer 2 and performs various processes such as control, calculation, and information transfer. The ADC 7 converts a signal (analog signal) indicating the measurement result and the state of the switch input from the various sensors and switches into the input circuit 3 into a digital signal so that the CPU 6 can process the signal. The DAC 8 converts the digital signal processed by the CPU 6 into an analog signal for controlling relays and solenoid valves of various control devices 15, and supplies the analog signal to the output circuit/output monitoring circuit 4.

The RAM 9 is used as a work area of the CPU 6 and stores various data. The ROM 10 stores a program describing a control procedure by the CPU 6, initial values and set values indicating the state of the engine, and the like. The program stored in the ROM 10 is read when the engine 14 is started, transferred to the RAM 9 or the like and stored, and the various control devices 15 are controlled based on the stored information. The engine 14 is provided with an alternator 16, which uses the rotation of the engine 14 as a power source to generate electric power and charge the battery 12.

Next, the operation of the electronic control unit shown in FIG. 1 will be described with reference to the flowchart of FIG. 2, the timing chart of FIG. 3, and the waveform diagrams of FIGS.
First, as shown in FIG. 2, the ECU 1 determines whether or not the coast regeneration is in progress (step S1). When it is determined that the regeneration is in progress, the charge/discharge amount of the battery 12 during the coast regeneration is determined by the current sensor 13. Is detected (step S2).

As shown in the waveform diagram of FIG. 3, for example, when the vehicle speed (VSP) is 80 km/h and the braking or accelerator is off (time t1), the vehicle is decelerated and stopped (0 km/h), The engine 14 becomes idle (time t4). In the coast regeneration, the alternator 16 generates electric power by using the energy that the vehicle decelerates, and the battery 12 is charged. During deceleration, the target equivalence ratio is decreased to increase the engine speed, so that the amount of power generated by the alternator 16 is increased and the voltage Vba of the battery 12 is increased from 12.6V to 14.5V, for example.
On the other hand, if it is determined in step S1 that coast regeneration is not being performed, the process waits until coast regeneration control is entered.

When the charge/discharge amount of the battery 12 is detected by the current sensor 13, it is input to the ADC 7 via the input circuit 3, converted into digital data, and stored in the RAM 9. The detection condition needs to be a battery liquid temperature that can secure a stable regeneration amount. For example, when the liquid temperature of the battery 12 is low or high, the regeneration amount is recognized as low and the detection accuracy deteriorates. Exclude it.

As shown in FIG. 4, in the present embodiment, the first to third thresholds Ta, Tb, and Tc of the discharge amount of the battery 12 are stored in the ROM 10 in advance. Here, the threshold Ta is −1000 mA/h and the threshold Tb. Is -2000 mA/h and the threshold value Tc is -3000 mA/h. The threshold value of the regenerative amount is a torque amount (unknown load amount) that deteriorates the engine stalling margin ratio during idling determined by each engine specification from the regenerative amount peak value determined by the state of the battery 12 and the power generation amount of the alternator 16. Set based on the subtracted value.

As shown in FIG. 5, in the coast down state, the peak current of the regeneration amount during coast down shown by the solid line 20 is estimated from the consumption current (discharge amount) detected by the current sensor 13, and the broken line 21 is set with respect to the set threshold value. When the peak current of the regenerative amount is lower as shown by, the unknown electric load which is not recognized by the vehicle side (referred to as an unknown load), for example, the user directly connects the load to the battery 12 It is determined that there is. This determination is executed for the first to third threshold values Ta, Tb, Tc, and the presence or absence of the unknown load is determined based on the determination result of each threshold value.

For example, if the peak current of the regenerative amount exceeds the threshold value Ta only once, it is determined that there is a variation in the current, and when it exceeds a predetermined number of times, it is determined that there is an unknown load. Further, when the peak current of the regeneration amount exceeds the threshold value Tc, it is determined that there is an unknown load even once. In this way, the presence or absence of an unknown load is determined by combining the levels of the thresholds Ta, Tb, and Tc, the number of times these thresholds are exceeded, the time until each threshold is exceeded, and the like.

That is, in step S3, the charge/discharge amount detected by the current sensor 13 and the discharge amount threshold value Ta stored in the ROM 10 in advance are compared by the CPU 6. When the charge/discharge amount is smaller than or equal to the threshold value Ta, the CPU 6 calculates the regenerative amount estimated value VA (step S4). On the other hand, when the charge/discharge amount is larger than the threshold value Ta, the charge/discharge amount is similarly compared with the discharge amount threshold value Tb stored in advance in the ROM 10 by the CPU 6 (step S5), and the charge/discharge amount is smaller than the threshold value Tb. When they are smaller than or equal to each other, that is, when “Ta<charge/discharge amount<Tb”, the estimated regeneration amount VB is calculated by the CPU 6 (step S6).

When the charge/discharge amount is larger than the threshold value Tb, the charge/discharge amount and the discharge amount threshold value Tc stored in advance in the ROM 10 are compared by the CPU 6 (step S7), and the charge/discharge amount is smaller than or equal to the threshold value Tc. That is, when “Tb<charge/discharge amount<Tc”, the regeneration amount estimated value VC is calculated by the CPU 6 (step S8). On the other hand, when the charge/discharge amount is larger than the threshold value Tc, the regeneration amount estimated value VD is calculated by the CPU 6 (step S9).

After obtaining the regenerative amount estimation values VA, VB, VC, VD in this way, whether the regenerative amount estimation value is smaller than the peak current of the charging/discharging amount in consideration of the level and duration of each regenerative amount estimation value. It is determined whether or not (step S10). In this way, by calculating the regeneration amount estimated values VA, VB, VC, and VD using the plurality of threshold values Ta, Tb, and Tc, variations in current consumption, influences of fluctuations in current consumption due to operation of an unknown load, and It is possible to suppress fluctuations in current consumption, effects of deterioration of the battery 12, and the like when the unknown load operates at different timings.

Then, when the peak current of the charge/discharge amount is smaller than or equal to the estimated regeneration amount value, it is determined that there is an unknown load (step S11), and when it is larger, the process returns to step S2 to perform coast regeneration. When it is determined that there is an unknown load, the target equivalence ratio is increased to reduce the engine speed, and the charging of the battery 12 is completed, as shown at the timing from time t2 to t3 in FIG. As a result, the voltage Vba of the battery 12 drops to 12.6V.

When the vehicle speed is reduced to 0 km/h and the vehicle is stopped (time t4) and becomes idle (step S12), the battery 12 is discharged at the timing of time t5 (step S13). The idle speed Idle at this time is, for example, 650 rpm, and the target voltage Vba of the battery 12 is, for example, 12.6V.

In this way, when the value falls below the above threshold value during coast regeneration, it is detected that there is an unknown load, and if the alternator is put into a non-power generation state (battery voltage is 12.6 V) from the next course down, the current of the battery 12 becomes negative. On the other hand, if the normal vehicle load is subtracted, the current consumption due to the unknown load can be found. With this, it is possible to measure how much electricity the unknown load connected to the cigarette lighter, the outlet, or the battery 12 consumes electricity. In FIG. 3, if the consumed current is -40 A and the load recognized by the vehicle is 15 A, it is understood that the unknown load consumes 25 A.

In the next step S14, the current value detected by the current sensor 13 is compared with the base current consumption value, and if the base current consumption value is large, the current value due to the unknown load is detected (step S15), and the engine load increases. Since the base current consumption value is large, the idling speed is controlled according to the electric load (step S16). At this time, the current value of the unknown load is replaced with torque, and the unknown load is added to the idle rotation. In addition, the engine speed added is added to the engine during idling to ensure stalling resistance. On the other hand, if the base current consumption value is small or equal, normal idling speed control is performed (step S17).

If the regenerative amount of the battery 12 stored in the ROM 10 in advance is exceeded, the threshold value is newly set (initial value), assuming that the battery 12 has been replaced (new).
In addition, for example, when the peak current of the charge/discharge amount gradually decreases over a long period from the threshold Ta to the threshold Tb and from the threshold Tb to the threshold Tc, it is determined that the deterioration of the battery 12 has an effect. In this case, the driver may be notified by a display device or a warning sound that the battery 12 is deteriorated.

As described above, the peak value of the regenerative amount is estimated at the time of coast down, and if the peak value of the regenerative amount is below the estimated value, the existence of the unknown load is suspected. Then, the existence of an unknown load is confirmed when the vehicle is in the decelerating state, the power consumption is estimated in the subsequent idle state, and the power generation amount during the idle is set.
By doing so, it is possible to compensate for an increase in current consumption due to an unknown load without incurring unnecessary increase in fuel consumption, improve idle stability, and suppress overdischarge of the battery.

Although the present invention has been described using the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. For example, an example in which three charge/discharge threshold values are set has been shown, but two threshold values may be set, or four or more threshold values may be set as necessary. Although the current sensor 13 is used to detect the charge/discharge amount of the battery 12, other sensors can be used as long as the charge/discharge current of the battery can be detected.

Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all constituent elements shown in the embodiment, at least one of the problems described in the section of the problem to be solved by the invention can be solved, and it is described in the section of the effect of the invention. When at least one of the effects is obtained, a configuration in which this constituent element is deleted can be extracted as an invention.

DESCRIPTION OF SYMBOLS 1... ECU (electronic control unit for automobile), 2... Microcomputer, 3... Input circuit, 4... Output circuit/output monitoring circuit, 5... Power supply circuit, 6... CPU, 7... A/D converter (ADC), 8 ... D/A converter (DAC), 9... Random access memory (RAM), 10... Read-only memory (ROM), 11... Bus, 12... Battery (power supply), 13... Current sensor, 14... Engine, 15... Various types Control equipment, 16... Alternator

Claims (3)

An electric load estimating means for estimating an electric load from the electric power consumption of the vehicle, and an electric power generation amount setting means for setting the electric power generation amount of the alternator when the engine is idle according to the electric load estimated by the electric load estimating means. Prepare,
An electronic control unit for an automobile, which detects a discharge amount of a battery during idling, and corrects the power generation amount of the alternator set by the power generation amount setting means according to a discharge amount of an electric load discharging the battery. There
When regenerative power generation is performed in the decelerated state of the vehicle, the peak value of the regenerative amount is estimated, and if the peak current of the regenerative amount is lower than the set threshold value, unknown on the vehicle side is unknown. A vehicle characterized by determining that there is an electric load , estimating the power consumption in the subsequent idle state, and correcting the power generation of the alternator during idle according to the power generation combined with the power consumption. Electronic control unit. When regenerative power generation is performed in a decelerated state of the vehicle, the presence or absence of an unknown electric load that is not recognized by the vehicle side is determined from the power generation state of the regenerative power generation and a predetermined threshold value, and the battery is discharged. it is determined that an unknown electric load that is not recognized by the vehicle side from the discharge amount of the electric load, automotive electronic control unit according to claim 1, characterized in that. The electronic control unit for an automobile according to claim 2, wherein the presence or absence of an unknown electric load which is not recognized on the vehicle side is determined at the time of coast down.