JP2001295683A - Idling engine speed control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain power consumption of a power battery, while vibration is controlled by a motor to the maximum in idling by enabling the vibration control under a condition, where the motor average torque is zero. SOLUTION: This idling engine speed control device of a hybrid vehicle is provided with an engine 1, a motor 52 rotated with the engine, the power battery 53 as a power supply for the motor 52, and a means 54 for conducting the rotating speed control for canceling variation in engine torque by the motor 52 during idling. The device is provided with a means 55 for controlling the engine torque to be increased, so that the motor average torque becomes zero, when the motor average torque during the control of rotating speed by the motor 52 is a positive value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle speed control device for a hybrid vehicle.

[0002]

2. Description of the Related Art There is known a hybrid vehicle having both an internal combustion engine (engine) and an electric motor (motor) as prime movers and running with one or both driving forces (Japanese Patent Laid-Open No. 8-182110). Reference).

[0003]

Meanwhile, in a hybrid vehicle, it is conceivable that vibration suppression control is performed using a motor that rotates with the engine in order to suppress vibration accompanying fluctuations in engine torque during idling. That is, as shown in the left half of FIG. 3, a motor torque having a phase exactly opposite to the periodically fluctuating engine torque is generated,
This motor torque cancels the fluctuation of the engine torque.

[0004] However, when the motor average torque per period of engine torque fluctuation or per predetermined period becomes a positive value, the electric power is discharged from the high-power battery as the power source of the motor. When the battery charge amount (SOC) falls below the minimum charge amount due to the power consumption of the high-power battery, it is necessary to stop the vibration suppression control using the motor, increase the engine speed, and force the high-power battery to perform forcible charging. Therefore, the opportunity to perform the vibration suppression control using the motor is limited.

Further, it has been confirmed by an experiment that the damping effect is maximized when the average motor torque is zero. Therefore, when the average motor torque is not zero, the damping effect is reduced.

Accordingly, in the present invention, the motor average torque is controlled by increasing the motor torque so that the motor average torque becomes zero when the motor average torque during the vibration suppression control using the motor is a positive value. It is an object of the present invention to make it possible to perform vibration suppression control in a state where is zero, thereby suppressing the power consumption of a high-power battery while maximizing vibration suppression using a motor during idling.

[0007]

According to a first aspect of the present invention, as shown in FIG. 11, an engine 51, a motor 52 that rotates with the engine, and a high-power battery 5 serving as a power source for the motor 52 are provided.
And means 54 for controlling the rotation speed by the motor 52 in such a direction as to cancel the fluctuation of the engine torque during idling.
Means 55 for controlling the engine torque to increase so that the motor average torque becomes zero when the motor average torque during the rotation speed control by the motor 52 is a positive value. Is provided.

[0008] In the second invention, the idle air amount when the engine torque is controlled to increase in the first invention is stored even after the engine is stopped.

According to a third aspect of the present invention, in the first aspect, the means for controlling the engine torque to increase increases the throttle control device and controls the throttle control device to increase the throttle valve opening by instructing the throttle control device. Means.

In a fourth aspect of the present invention, the throttle valve opening when the throttle valve opening is controlled to increase in the third aspect is stored even after the engine is stopped.

In a fifth aspect based on the second aspect, the idle air amount is a sum of an additional idle air amount and a base idle air amount corresponding to the positive motor average torque.

In a sixth aspect, in the fifth aspect, the base idle air amount is a value preset so as to obtain a target idle speed.

In a seventh aspect, in the fifth aspect, the base idle air amount is a value learned so as to obtain a target idle speed in a state where the motor does not generate torque at the time of shipment from a factory. is there.

[0014]

According to the first, second, third and fourth aspects of the present invention, it is possible to control the rotation speed by the motor in a state where the average motor torque is zero. Vibration suppression can be performed to a maximum by the speed control, and the power consumption of the high-power battery can be suppressed.

According to the fifth and sixth aspects, the motor average torque can be accurately reduced to zero regardless of the magnitude of the motor average torque.

According to the seventh aspect, the rotation speed control by the motor is stopped when learning the base idle air amount at the time of factory shipment. Therefore, the rotation speed control by the motor is also performed at the time of learning the base idle air amount at the time of factory shipment. Erroneous learning due to performing can be prevented.

[0017]

1 and 2 show an example of the configuration of a hybrid vehicle. Each of these is a parallel type hybrid vehicle that runs using either or both of the power of the engine and the motor according to the running conditions.

In FIG. 1, a thick solid line indicates a transmission path of mechanical force, and a thick broken line indicates a power line. A thin line indicates a control line, and a double line indicates a hydraulic system. The power train of this vehicle includes a motor 1, an engine 2, a clutch 3, a motor 4, a continuously variable transmission 5, a reduction gear 6, a differential gear 7, and driving wheels 8. The output shaft of the motor 1, the output shaft of the engine 2, and the input shaft of the clutch 3 are connected to each other, and the output shaft of the clutch 3, the output shaft of the motor 4, and the input shaft of the continuously variable transmission 5 are connected to each other. ing.

When the clutch 3 is engaged, the engine 2 and the motor 4
Is the propulsion source of the vehicle, and when the clutch 3 is released, only the motor 4 is the propulsion source of the vehicle. The driving force of the engine 2 or the motor 4 is controlled by a continuously variable transmission 5, a reduction gear 6, and a differential gear 7.
Is transmitted to the drive wheels 8 via Pressure oil is supplied from the hydraulic device 9 to the continuously variable transmission 5 to clamp and lubricate the belt. An oil pump (not shown) of the hydraulic device 9 is driven by a motor 10.

The motor 1 is mainly used for starting the engine and generating electric power, and the motor 4 is mainly used for propulsion (powering) and control of the vehicle. The motor 10 is for driving the oil pump of the hydraulic device 9. Further, when the clutch 3 is engaged, the motor 1 can be used for propulsion and braking of the vehicle, and the motor 4 can be used for starting the engine and generating power. The clutch 3 is a powder clutch, and can adjust the transmission torque. The continuously variable transmission 5 is a continuously variable transmission of a belt type, a toroidal type, or the like, and can continuously adjust the speed ratio.

The motors 1, 4, and 10 are driven by inverters 11, 12, and 13, respectively. When a DC electric motor is used for the motors 1, 4, and 10, a DC / DC converter is used instead of the inverter. The inverters 11, 12, and 13 are connected to a high-power battery (42V battery) 15 via a common DC link 14, convert DC charging power of the high-power battery 15 into AC power, and supply the AC power to the motors 1, 4, and 10. At the same time, the AC power generated by the motors 1 and 4 is converted into DC power to charge the high-power battery 15. Since the inverters 11 to 13 are connected to each other via the DC link 14, the electric power generated by the motor during the regenerative operation is transferred to the strong electric battery 15.
Can be supplied directly to the motor during the power running operation without going through. Various batteries such as lithium-ion batteries, nickel-metal hydride batteries, and lead batteries, and electric double layer capacitors, so-called power capacitors, are applied to the high-power battery 15.

A controller 16 includes a microcomputer and its peripheral parts, various actuators, etc., and transmits torque of the clutch 3, rotation speeds and output torques of the motors 1, 4, 10, speed ratio of the continuously variable transmission 5, The fuel injection amount, injection timing, ignition timing, and the like of the engine 2 are controlled.

As shown in FIG. 2, the controller 16 includes a key switch 20, a select lever switch 21,
Accelerator pedal sensor 22, brake switch 23, vehicle speed sensor 24, battery temperature sensor 25, battery SO
A C detection device 26, an engine rotation speed sensor 27, and a throttle opening sensor 28 are connected. Key switch 20
Closes when the key of the vehicle is set to the ON position or the START position (hereinafter, the closing of the switch is referred to as ON and the opening of the switch is referred to as OFF). The select lever switch 21 switches any one of P, N, R, and D according to the set position of a select lever (not shown) that switches the range to one of parking P, neutral N, reverse R, and drive D. Turns ON.

The accelerator pedal sensor 22 detects the amount of depression of the accelerator pedal, and the brake switch 23 detects the amount of depression of the brake pedal (switch ON at this time). The vehicle speed sensor 24 detects the running speed of the vehicle, and the battery temperature sensor 25 detects the temperature of the high-power battery 15. The battery SOC detection device 26 has an SOC (State Of) which is a representative value of the actual capacity of the high-power battery 15.
Charge). Further, the engine rotation speed sensor 27 detects the rotation speed of the engine 2, and the throttle opening sensor 28 detects the throttle valve opening of the engine 2.

The controller 16 also includes a fuel injection device 41, an ignition device 42, a variable valve device 43,
An electronic control throttle control device (driving a butterfly-shaped throttle valve using a DC motor as a throttle actuator) 44 and the like are connected. Controller 1
6 controls the throttle valve 44 and the fuel injection device 41 so as to obtain a predetermined target torque with a target of a stoichiometric air-fuel ratio or an air-fuel ratio leaner than the stoichiometric air-fuel ratio, thereby controlling the throttle valve opening and the fuel supply to the engine 2. While adjusting the amount, the ignition device 42 is driven to control the ignition timing of the engine 2. Further, the controller 16 controls the variable valve operating device 43 to adjust the operation state of the intake and exhaust valves of the engine 2. The controller 16 is supplied with power from a low-voltage auxiliary battery (12 V battery) 33.

The controller 16 also generates a motor torque having a phase exactly opposite to that of the engine torque in order to suppress the vibration caused by the fluctuation of the engine torque at the time of idling. The rotation speed of the motor 1 is controlled so as to cancel each other (see FIG. 3). The method of controlling the rotation speed using the motor 1 itself is known and will not be described in detail.

In this case, when the motor average torque becomes a positive value, the power of the high-power battery 15 is consumed. To avoid this, the controller 16 sets the motor average torque during the rotation speed control of the motor 1 to a positive value. In this case, control is performed so that the engine torque increases (for example, the intake air amount increases) so that the motor average torque becomes zero. In this case, since the intake air amount changes according to the throttle valve opening, the intake air amount of the engine is increased by increasing the throttle valve opening.

The contents of this control executed by the controller 16 will be described with reference to the flowchart of FIG.

FIG. 4 is for calculating the throttle valve target opening during idling.
(Every 0 ms).

In step 1, it is determined whether or not the feedback control condition for the idle speed is satisfied. The feedback control condition is when the following two conditions are satisfied, and if any one of them is released, the feedback control condition is not satisfied and the feedback control is stopped.

The throttle valve opening is at the idle position.

The vehicle speed is equal to or lower than a predetermined value or the select lever is in a neutral position.

When the feedback control condition is satisfied, the routine proceeds to step 2, where it is checked whether or not the learning of the additional idle air amount has been completed by using a flag (an additional idle air amount learned flag described later in step 11). When the learning of the additional idle air amount has not been completed (additional idle air amount learning completed flag = 0), the process proceeds to step 3 and thereafter to learn the additional idle air amount. Specifically, first, in step 3, the current value of the motor 1 is sampled. However, the description will be made on the assumption that the rotation speed control for vibration suppression by the motor 1 is being performed at the time of idling. Therefore, the motor 1 current value here is the motor 1 current value during rotation speed control for vibration suppression.

Steps 5, 6, and 7 are performed until the number of samples of the motor 1 current value reaches a predetermined value. That is, in step 5, the base idle air amount is set as the target idle air amount. The base idle air amount is the target idle rotation speed NS
This is a value set in advance so that ET can be obtained. Since the target idle rotation speed NSET changes according to the water temperature, the air conditioner, the gear position, and the like, the base idle air amount also changes according to the water temperature, the air conditioner, the gear position, and the like. Here, for simplicity, the case where NSET is a constant value will be described. At this time, the base idle air amount is a fixed value.

In steps 6 and 7, the value obtained by searching the table of FIG. 5 from the target idle air amount is calculated as the throttle valve target opening area, and the table of FIG. 6 is searched from the target opening area. The calculated value is calculated as the throttle valve target opening.

The throttle valve target opening calculated in this way is a DC motor (throttle actuator).
And output. If the actual throttle valve opening detected by the throttle opening sensor 28 does not match the target opening, feedback control is performed so as to match.

On the other hand, when the number of samples of the motor 1 current value has reached a predetermined number, the process proceeds to steps 8 to 12. That is, in step 8, the motor 1 average torque is calculated using a predetermined number of motor 1 current values (sample values). Motor 1
Since the method of calculating the average torque is known, the description is omitted.

In step 9, a value obtained by searching the table of FIG. 7 from the average torque of the motor 1 is calculated as an additional idle air amount, and this value is stored in the memory (RAM) in the controller 16 in step 10. This completes the learning of the additional idle air amount, so that the additional idle air amount learned flag is switched from 0 to 1 in step 11.

The above-mentioned additional idle air amount is an air amount for additionally generating the motor 1 average torque (however, the motor average torque is a positive value) during rotation speed control for vibration suppression by the engine. It is. In step 12, a value obtained by adding the additional idle air amount to the base idle air amount is calculated as the target idle air amount, and then the processes in steps 6 and 7 are executed.

As shown in FIG. 7, when the motor 1 average torque is a negative value, the additional idle air amount is given as a negative value. This is for the following reason. When the average torque of the motor 1 is a negative value, the high-power battery 15 is overcharged, and the deterioration of the high-power battery is accelerated. Therefore, the vibration damping control using the motor may be stopped to avoid this. Thus, the opportunity for performing the vibration suppression control is limited. Therefore, in order to make the average torque of the motor 1 zero even when the average torque of the motor 1 is a negative value, a negative value is given to the additional idle air amount, The control is such that the torque is reduced (see FIG. 10). As a result, the deterioration of the high-power battery 15 can be prevented, and the opportunity for performing the vibration suppression control is not limited.

If the feedback control condition is satisfied even after the additional idle air amount learned flag = 1, the process proceeds from Step 2 to Steps 13 and 14 from the next time, and the additional idle air read from the memory is read. The target idle air amount is calculated by adding the air amount to the base idle air amount. In steps 6 and 7, the throttle valve opening is controlled so that the target idle air amount flows.

Thereafter, when the engine 2 is stopped, the additional idle air amount stored in the memory is transferred to the EEPROM so that the value does not disappear.

Here, the operation of the present embodiment will be described with reference to FIG. 3. The right half of the figure is the case of the present embodiment. According to the present embodiment, when the rotational speed control is performed by the motor 1 for damping during idling, and the average torque of the motor 1 is a positive value, the idle air amount is increased to increase the motor 1 having the positive value. Since the extra torque is generated by the engine for the average torque, the rotation speed control by the motor 1 can be performed in a state where the average torque of the motor 1 is zero. The power consumption of the high-power battery 15 can be suppressed while maximally damping by the speed control.

Since the idling rotational speed is determined by the sum of the engine torque and the motor torque, the idling rotational speed does not change even if the engine generates extra motor torque corresponding to the motor average torque.

Now, in an engine equipped with an electronically controlled throttle device, in order to prevent a target idle rotation speed from being obtained due to a throttle valve installation error or the like, a throttle valve opening degree is set for each vehicle at the time of shipment from a factory. Is adjusted to obtain the target idle rotation speed, and then the air amount at this time (that is, the base idle air amount) is learned. In this case, too, the rotation speed control by the motor 1 for vibration suppression is performed. If performed, erroneous learning occurs when the motor average torque has a non-zero value.
This is because the base idle air amount should be a value for the engine alone, but the idling speed is determined by the sum of the engine torque and the motor torque during the operation of the motor, so the motor torque is generated as an error. To come. For example, even when the throttle valve opening is the same, when the motor average torque is a positive value, the idle rotation speed increases by that amount, and conversely, when the motor average torque is a negative value, the idle rotation speed decreases by that amount. I do.

Therefore, when learning the base idle air amount at the time of shipment from the factory, the rotation speed control by the motor 1 is stopped.

The details of the control executed by the controller 16 will be described in detail with reference to FIG. 8. In step 21, it is determined whether or not an instruction to learn the base idle air amount has been received. The instruction for learning is executed by a diagnostic tool or a similar hand tool (not shown). That is, a hand tool capable of communicating with the controller 16 is connected to the controller 16, and the hand tool is operated to instruct the controller 16 to learn the base idle air amount.

When a learning instruction is received, step 22
To stop the rotation speed control by the motor 1
Zero the torque.

In step 23, it is checked whether or not the base idle air amount has been learned from a flag (a base idle air amount learned flag in step 35 described later). If the base idle air amount has not yet been learned (base idle air amount learned flag = 0), the process proceeds to step 24, and it is determined whether or not the condition is a feedback control condition of the idle rotation speed. If it is not the feedback control condition, step 3
6 to maintain the throttle valve target opening at the same level as the previous time (tT, which is the previous value of the throttle valve target opening,
VOz is directly shifted to the current value of the throttle valve target opening, tTVO). The initial value of the throttle valve target opening has a predetermined fixed value.

When the feedback control condition is satisfied, the routine proceeds to step 25, where the actual engine rotational speed Ne detected by the rotational speed sensor 27 is read, and the absolute value of the difference between the actual engine rotational speed Ne and the target idle rotational speed NSET and the allowable value ε are determined in step 2.
Compare with 6. Here, the case where Ne deviates from NSET by more than an allowable value will be described.
Proceed to 7 to compare NSET with Ne. Ne is NSET
If it is lower, in order to increase Ne to NSET, in step 28, the throttle valve target opening tTVO is set to a constant value Δ
Increase by TVO. As the throttle valve opening increases, the amount of intake air increases, and the engine speed increases. If the value is still outside the allowable value ε, the process of step 28 is repeated. As a result, Ne eventually settles within the allowable value ε centered on NSET.

The same applies when Ne is higher than NSET. In order to reduce Ne to NSET, the throttle valve target opening tTVO is reduced by a constant value ΔTVO in step 29. Due to the decrease in the throttle valve opening, the amount of intake air decreases, and the engine speed decreases. If the value is still outside the allowable value ε, the process of step 29 is repeated. As a result, Ne eventually settles within the allowable value ε centered on NSET.

When Ne has settled within the allowable value ε centered on NSET in this way, the process proceeds to step 30, and
Maintain the target throttle valve opening as before. In steps 31 and 32, the throttle valve opening area is calculated by searching a table having the contents shown in FIG. 6 from the target throttle valve opening at that time, and a table having the contents shown in FIG. 5 is further searched from the opening area. By doing so, the idle air amount is calculated. Then, in steps 33 and 34, this idle air amount is put into the base idle air amount, and this base idle air amount is stored in the memory (RAM) in the controller 16. This completes the learning of the base idle air amount, so that the base idle air amount learned flag is switched from 0 to 1 in step 35.

This base idle air amount learned flag =
From step 23, the process proceeds from step 23 to step 36, and the target throttle valve opening is maintained at the same value as the previous time.

When the learning of the base idle air amount at the time of shipment from the factory is completed in this way, an instruction to cancel the learning of the base idle air amount by the hand tool is issued, and then the hand tool is removed from the controller 16.

Thereafter, when the engine 2 is stopped, the base idle air amount stored in the memory (RAM) is transferred to the EEPROM so that the value does not disappear.

As described above, according to the second embodiment, the rotation speed control by the motor 1 is stopped when learning the base idle air amount at the time of shipment from the factory. Erroneous learning caused by performing the rotation speed control by the control can be prevented.

In the embodiment, when the motor average torque is a positive value, the additional idle air amount is calculated so that the motor average torque becomes zero, and this additional idle air amount is stored in the EEPROM so that the value does not disappear when the engine is stopped. As described above, when the motor average torque is a positive value, the throttle valve opening when the engine torque is controlled to increase so that the motor average torque becomes zero so that the value does not disappear when the engine stops. May be transferred to the EEPROM.

In the embodiment, the case where the torque waveform at the time of the rotation speed control by the motor for damping is a sine curve approximation (see FIG. 3) is not limited to this. As shown, the torque waveform may be a rectangular waveform, or the motor rotation speed may be controlled by chopper drive or PWM drive. The point is that any motor torque may be used as long as the motor torque is generated so as to have a phase opposite to the periodically fluctuating engine torque and cancel the fluctuation of the engine torque.

Although the embodiment has been described in the case where the throttle control device of the electronic control is provided, the present invention is also applicable to the case where the auxiliary air control valve controlled by the controller is provided in the passage bypassing the throttle valve linked to the accelerator pedal. The invention can be applied.

Although the embodiment has been described in the idle state, the present invention is not limited to the idle state, and the present invention can be similarly applied as long as the load is close to the idle state.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration example of a hybrid vehicle to which the present invention can be applied.

FIG. 2 is a block diagram of a controller.

FIG. 3 is a waveform chart showing the operation of the first embodiment when the motor average torque is a positive value.

FIG. 4 is a flowchart showing a control operation performed by a controller.

FIG. 5 is a characteristic diagram showing a relationship between an idle air amount and a throttle valve opening area.

FIG. 6 is a characteristic diagram showing a relationship between a throttle valve opening area and a throttle valve opening;

FIG. 7 is a characteristic diagram showing a relationship between a motor average torque and an additional idle air amount.

FIG. 8 is a flowchart illustrating a control operation performed by a controller according to the second embodiment.

FIG. 9 is a waveform chart showing the operation of the third embodiment.

FIG. 10 is a waveform chart showing the operation of the first embodiment when the motor average torque is a negative value.

FIG. 11 is a diagram corresponding to claims of the first invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor (motor accompanying an engine) 2 Engine 15 High-power battery 16 Controller 27 Rotation speed sensor 44 Throttle control device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F02D 9/02 351 F02D 11/10 H 11/10 29/02 D 29/02 41/08 310 41/08 310 45/00 376E 45/00 376 B60K 9/00 EF term (reference) 3G065 AA04 BA06 CA00 DA04 EA03 EA06 FA12 FA13 GA00 GA05 GA09 GA10 GA11 GA29 GA31 GA37 GA41 GA46 HA22 JA04 JA09 JA11 KA02 3G084 BA03 BA03 BA03 CA03 DA02 DA11 DA21 EA04 EA11 EB06 EB08 EB11 EB17 EC03 FA03 FA05 FA06 FA10 FA20 FA32 FA33 FA36 3G093 AA07 BA02 BA27 CA04 CA06 DA01 DA05 DA06 DA12 DB05 DB11 DB12 DB15 DB19 DB25 EA03 EA05 EA09 EC02 FA02 FA04 FA09 FA11 KA03 JA03 JA04 LA03 LA07 LC03 MA11 MA18 NA01 NA08 NB03 NC01 NC02 ND01 ND21 NE15 PA11A PA11Z PA14Z PE01A PE01Z PE06Z PE08Z PF01Z PF03Z PF05Z PF07Z PF10Z PF13Z PF16Z P G01Z 5H115 PA11 PC06 PG04 PI16 PI21 PI23 PU02 PU22 PU23 PV02 PV09 RB08 RB17 RE07 SE05 SE06 SF01 TE03

Claims (7)

[Claims] 1. A hybrid vehicle comprising: an engine; a motor that rotates with the engine; a high-power battery serving as a power source for the motor; and means for controlling a rotation speed by the motor so as to cancel fluctuations in engine torque during idling. The idle rotation speed control device according to claim 1, further comprising: means for controlling the engine torque to increase so that the motor average torque becomes zero when the motor average torque during the rotation speed control by the motor is a positive value. An idle speed control device for a hybrid vehicle. 2. The idle speed control device for a hybrid vehicle according to claim 1, wherein the idle air amount when the engine torque is controlled to increase is stored even after the engine is stopped. 3. The means for controlling the engine torque to increase the engine torque comprises a throttle control device and means for instructing the throttle control device to control the throttle valve opening to increase the throttle valve opening. The idle speed control device for a hybrid vehicle according to claim 1. 4. The idle speed control device for a hybrid vehicle according to claim 3, wherein the throttle valve opening when the throttle valve opening is controlled to be increased is stored even after the engine is stopped. . 5. The hybrid vehicle according to claim 2, wherein the idle air amount is a sum of an additional idle air amount and a base idle air amount corresponding to the positive motor average torque. Idle speed control device. 6. The idle speed control device for a hybrid vehicle according to claim 5, wherein the base idle air amount is a value set in advance so as to obtain a target idle speed. 7. The system according to claim 5, wherein the base idle air amount is a value learned so as to obtain a target idle rotation speed in a state where the motor does not generate torque at the time of shipment from a factory. 3. The idle speed control device for a hybrid vehicle according to claim 1.