JP2022156731A - Vehicle, control device, control method and program - Google Patents

Abstract

To suppress an output shaft of an engine from resonating when the engine misfires.SOLUTION: A vehicle is equipped with: an engine provided with an output shaft that outputs power; a twisting part that makes a twisting moment act on the output shaft; a rotating electric machine, connected to the output shaft through the twisting part, which generates torque for power generation; and a delay control part that performs delay control by which the generation of the torque is delayed, when the engine rotates at a specific rotation speed when the engine misfires.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle, control device, control method, and program.

In recent years, hybrid vehicles have become popular. In a hybrid vehicle, feedback control is performed to control the rotation speed of a motor in order to achieve a target engine rotation speed. As a related technique, the target rotation speed and target torque of the engine are set based on the required torque, and the estimated engine torque is estimated by considering whether the exhaust gas is supplied to the intake side. Setting commands to control an engine and a motor has been disclosed (see, for example, Patent Document 1).

Also, the hybrid vehicle is equipped with an engine. This engine is, for example, a multi-cylinder engine. A multi-cylinder engine can continue to rotate without stopping even if a misfire occurs in one of the cylinders.

Japanese Patent Application Laid-Open No. 2008-290560

However, when the engine rotates at a specific number of revolutions at the time of a misfire, resonance may occur in the drive system if feedback control is performed. This may increase the input torque to the transmission.

SUMMARY OF THE INVENTION The present invention has been made in consideration of such circumstances, and one of the objects thereof is to be able to suppress the resonance of the drive system caused by a misfire.

A vehicle, a control device, a control method, and a program according to the present invention employ the following configurations.
(1): A vehicle according to one aspect of the present invention includes an engine having an output shaft that outputs power, a twist portion that applies a torsional moment to the output shaft, and a torsion portion that is connected to the output shaft via the torsion portion. a rotary electric machine that generates torque for power generation; and a delay control unit that performs delay control to delay the generation of the torque when the engine rotates at a specific number of revolutions when the engine misfires.

(2): In the aspect of (1) above, a detection section is provided for detecting resonance of the output shaft caused by the torsional moment, and the delay control section detects the resonance when the detection section detects the resonance. control.

(3): In the aspect (1) or (2) above, an engine control unit that controls the engine; a rotating electrical machine control unit that controls the rotating electrical machine based on instructions received from the engine control unit; and the delay control unit controls a communication delay time between the engine control unit and the rotating electric machine control unit, a phase delay time due to physical torsion of the flywheel, and resonance at the time of a misfire. The delay control is performed based on the delay time of

(4): In the aspect of (3) above, the delay control section is provided in either one of the engine control unit and the rotating electric machine control unit.

(5): A control device according to an aspect of the present invention includes an engine having an output shaft that outputs power, a twisting portion that applies a torsional moment to the output shaft, and a torque on the output shaft via the twisting portion. and a rotating electric machine that is connected to generate torque for power generation, the control device for use in a vehicle, wherein when the engine misfires and the engine rotates at a specific number of revolutions, the generation of the torque is delayed. a delay control unit that performs delay control to cause the

(6): A control method according to one aspect of the present invention includes an engine having an output shaft that outputs power, a twisting portion that applies a torsional moment to the output shaft, and a torque on the output shaft via the twisting portion. and a computer used in a vehicle equipped with a rotating electrical machine connected to generate torque for power generation, and a delay control for delaying the generation of the torque when the engine misfires and the engine rotates at a specific number of revolutions. I do.

(7): A program according to one aspect of the present invention includes an engine having an output shaft that outputs power, a twisting section that applies a torsional moment to the output shaft, and a engine connected to the output shaft via the twisting section. a rotating electric machine that generates torque for power generation, and a computer used in a vehicle that includes a delay control that delays the generation of the torque when the engine is rotating at a specific number of revolutions when the engine misfires. let it happen

According to (1) to (7), it is possible to suppress the resonance of the drive system caused by misfiring.

It is the figure which illustrated the drive system 100 used for the hybrid vehicle M which concerns on embodiment. FIG. 3 is a diagram showing the phase of generator torque and the phase of engine rotation speed; It is an example of a time chart at the time of a misfire. 4 is a flowchart showing an example of a process performed by engine ECU 120 at the time of a misfire. It is an example of experimental results showing the relationship between delay control, engine rotation speed, and transmission input torque.

Hereinafter, embodiments of a vehicle, a control device, a control method, and a program according to the present invention will be described with reference to the drawings.

[Embodiment]
[Configuration of Drive System 100 Used in Hybrid Vehicle]
FIG. 1 is a diagram illustrating a drive system 100 used in a hybrid vehicle M according to an embodiment. As shown in FIG. 1 , drive system 100 includes engine 110 , engine ECU (Electronic Control Unit) 120 , flywheel 130 , transmission 140 , motor ECU 150 , PDU (Power Drive Unit) 160 , generator 170 . and

Engine 110 outputs power using gasoline, light oil, or the like as fuel. That is, engine 110 is a gasoline engine or a diesel engine. In this embodiment, the engine 110 is, for example, a four-cylinder gasoline engine. Engine ECU 120 (an example of an engine control unit) is an electronic control unit that controls engine 110 . Engine ECU 120 is also an example of a control device.

Flywheel 130 (an example of a twisted portion) is provided on crankshaft 111 (an example of an output shaft of engine 110). Flywheel 130 is a damper that stabilizes the rotation of crankshaft 111 . Specifically, flywheel 130 rotates due to the output from engine 110 and generates a moment of inertia due to the rotation. The flywheel 130 stabilizes the rotation of the crankshaft 111 with this moment of inertia. Further, the flywheel 130 has therein a torsion spring that dynamically absorbs torsional vibration of the crankshaft 111 . Transmission 140 is a transmission.

The motor ECU 150 (an example of a rotating electrical machine control unit) is an electronic control unit that controls a driving motor (not shown) and a generator 170 (an example of a rotating electrical machine). The PDU 160 is a device that converts the DC power of the lithium ion battery into three-phase AC power and transmits it to the motor. PDU 160 includes an inverter. The generator 170 is a motor for power generation that uses the rotation of the engine 110 as a power source. Specifically, the generator 170 uses the rotational force of the crankshaft 111 to generate torque for power generation (hereinafter referred to as “generator torque”) to generate power.

The engine ECU 120 performs feedback control of the engine speed. In the feedback control, engine ECU 120 transmits to motor ECU 150 an instruction to generate torque for setting the engine speed to the target speed. Based on the instruction, the motor ECU 150 performs control to rotate the driving motor at a predetermined number of revolutions in order to bring the number of revolutions of the engine to the target number of revolutions, and regenerates the generator 170 with a predetermined torque. control to allow

Here, in engine 110, one of the four cylinders may misfire. When engine 110 misfires, the cylinder in which the misfire occurred does not operate, resulting in fluctuations in rotation of engine 110 . In particular, when engine 110 rotates at a specific number of revolutions during a misfire, resonance (hereinafter referred to as “misfire resonance”) may occur in crankshaft 111 . The specific number of rotations is a number of rotations corresponding to the natural frequency based on the moment of inertia of the engine and the generator and the characteristic value of the spring mass system of the torsion spring provided in the flywheel 130 . If feedback control of the rotation speed is performed while the engine is vibrating at the natural frequency, the vibration may be increased, and misfire resonance may occur. This will be specifically described with reference to FIG.

FIG. 2 is a diagram showing the phase of the generator torque and the phase of the rotational speed of the engine 110. As shown in FIG. FIG. 2A shows each phase when misfire resonance does not occur. As shown in FIG. 2A, the waveform of the generator torque and the waveform of the rotation speed of the engine 110 show waveforms with a phase of τ. When misfire resonance does not occur, the phase of the generator torque and the phase of the rotation speed of the engine 110 are opposite to each other, and they act to suppress vibrations.

On the other hand, FIG. 2B shows each phase when misfire resonance occurs. At a specific engine speed at the time of a misfire, if a phase shift occurs in the generator torque, as shown in FIG. Misalignment occurs and they reinforce each other. As a result, the amplitude (vibration) increases, that is, misfire resonance occurs.

Therefore, in the present embodiment, the misfire resonance is suppressed by delaying the generation of the generator torque by τ′. This will be described in detail below. Engine ECU 120 includes misfire detector 121 , resonance detector 122 , delay controller 123 , and feedback controller 124 .

Generator 170 is connected to the output shaft of engine 110 via a twisted portion including crankshaft 111 and flywheel 130 . Specifically, generator 170 is connected to the output shaft via torsion and transmission 140 . The torsional portion applies a torsional moment to the crankshaft 111 . Misfire resonance is caused by the torsional moment of the torsion portion when engine 110 rotates at a specific number of revolutions at the time of misfire. Although there is a clutch in transmission 140, the clutch does not cause misfire resonance. That is, the torsion does not include the clutch.

The misfire detector 121 detects engine misfire. Engine misfires can occur while the engine is running, and more specifically, they can occur both when the engine is stopped (when the vehicle is started) and when the vehicle is running. A misfire detection unit 121 detects a misfire using the detection results of various sensors. Various sensors include, for example, a crank angle sensor that detects the crank angle of the crankshaft 111, a rotation speed sensor that detects the rotation speed of the crankshaft 111, and a rotation speed sensor that detects the rotation speed of the input shaft 171 of the generator 170. is. Note that the detection result of the crank angle sensor and the detection result of the rotation speed sensor may differ due to, for example, slipping of the clutch in the transmission 140, but they are usually the same.

Misfire detection unit 121 detects occurrence of misfire by analyzing the detection result of the crank angle sensor or the detection result of the rotation speed sensor. A known method can be used to determine misfire. As an example, when the detection result of the crank angle sensor is used to determine misfire, the misfire detection unit 121 calculates the area (misfire parameter) by integrating the angular velocity with respect to the top dead center for each cylinder. It is possible to determine combustion and misfire if the area is small.

Resonance detector 122 detects misfire resonance when misfire is detected by misfire detector 121 . For example, the resonance detector 122 passes the rotation speed of the engine 110 through a band-pass filter corresponding to the resonance frequency, and detects misfire resonance when the amplitude of the signal is equal to or greater than a predetermined value. Note that misfire resonance is resonance that occurs during a misfire. Therefore, the resonance detector 122 may detect misfire resonance (resonance of the natural frequency) only during a misfire. It is also possible not to detect misfire resonance.

Feedback control unit 124 performs feedback control to control the generation of generator torque in order to set engine 110 to a target rotational speed.

Delay control unit 123 performs delay control to delay the generation of generator torque when engine 110 rotates at a specific rotational speed when engine 110 misfires. Specifically, when the resonance detector 122 detects misfire resonance, the delay controller 123 performs delay control to delay generation of generator torque. More specifically, when misfire resonance is detected, delay control unit 123 transmits an instruction (control signal) to motor ECU 150 to delay generation of generator torque related to feedback control by feedback control unit 124 . When engine 110 rotates at a specific speed when engine 110 misfires, and it can be assumed that misfire resonance occurs, delay control unit 123 performs delay control even if misfire resonance is not detected. may

It should be noted that, as described above, the misfire resonance is the resonance of the natural frequency. For example, the resonance frequency of misfire resonance is an eigenvalue regardless of whether misfire occurs in one cylinder or two cylinders. Therefore, the delay value is a constant value regardless of the misfire state or the number of misfiring cylinders.

Here, motor ECU 150 causes generator 170 to generate generator torque based on the control signal (instruction) received from engine ECU 120 . There is a delay due to communication between the engine ECU 120 and the motor ECU 150 . That is, the timing at which motor ECU 150 receives the control signal is delayed from the timing at which engine ECU 120 transmits the control signal. A delay in transmission of the control signal may also increase the vibration at the natural frequency, causing misfire resonance. Therefore, the delay control unit 123 performs delay control in consideration of communication delays between the engine ECU 120 and the motor ECU 150 . Note that this delay is also an eigenvalue. Therefore, the value delayed by the delay control unit 123 is a constant value.

Feedback control at normal time is controlled by “τ1+τ2”. τ1 is the transmission delay time of the control signal between engine ECU 120 and motor ECU 150 . τ2 is the phase lag time due to the physical torsion of the flywheel 130; On the other hand, the feedback control at the time of misfire is controlled by "τ1+τ2+τ3". τ3 is a delay time added to normal feedback control in order to suppress resonance during misfire.

Moreover, the delay control unit 123 may be provided on the route from the engine ECU 120 to the PDU 160 . In this embodiment, the delay control section 123 is provided in the engine ECU 120 . As a result, there is no need to add a new part having the function of the delay control unit 123 . Note that the delay control unit 123 may be provided in the motor ECU 150 so as not to increase the number of new components. Also, the delay control unit 123 may be provided between the engine ECU 120 and the motor ECU 150 or between the motor ECU 150 and the PDU 160 .

Each function of engine ECU 120 and motor ECU 150 is implemented by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components are hardware (circuits) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit) (including circuitry), or by cooperation of software and hardware. The program may be stored in advance in a storage device (not shown) such as an HDD or flash memory of the engine ECU 120 and the motor ECU 150, or may be stored in a removable storage medium such as a DVD or CD-ROM. It may be installed in the HDD or flash memory of engine ECU 120 and motor ECU 150 by attaching the medium to the drive device.

Further, engine ECU 120 and motor ECU 150 may include storage units. The storage unit is implemented by a storage device such as RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), flash memory, or the like. Information stored in the storage unit may be stored in an external device (for example, management server Sv) accessible by the control device 400 .

[Time chart at misfire]
FIG. 3 is an example of a time chart at the time of misfire. FIG. 3(A) shows a time chart of the engine rotation speed. In FIG. 3(A), times t1 to t2 show the variation from the target speed due to misfire. FIG. 3B shows a time chart of misfire detection. In FIG. 3B, times t1 to t2 indicate that a misfire has been detected.

FIG. 3(C) shows a time chart for detection of misfire resonance. In FIG. 3C, time t3 to t4 indicates that misfire resonance occurs. Since the misfire ends at the time t2, the misfire resonance also ends at the timing of the time t2. Therefore, detection of misfire resonance may be ended at the timing of time t2. Note that even if resonance of a frequency corresponding to misfire resonance is detected in the range from t2 to t4, delay control of the generator torque is not performed because misfire is not occurring.

FIG. 3D shows a time chart of delay control of generation of generator torque. In FIG. 3D, from time t5 to t6, it is shown that delay control of generation of generator torque is being performed. The delay control is started when both misfire and misfire resonance are detected, and ends when at least one of misfire and misfire resonance is not detected. Specifically, time t5 indicates the timing at which both misfire and misfire resonance are detected and delay control is started. Time t6 indicates the timing at which the misfire is no longer detected and the delay control ends.

[Processing performed by engine ECU 120 at the time of misfire]
FIG. 4 is a flowchart showing an example of delay control determination processing by engine ECU 120 . In FIG. 4, the misfire detector 121 determines whether or not a misfire has been detected (step S401). Resonance detector 122 waits until misfire is detected by misfire detector 121, and when misfire is detected, determines whether engine 110 is at a specific rotational speed (step S402). If the engine 110 is not at the specific rotational speed, the resonance detector 122 moves to step S405.

When engine 110 is at the specific rotational speed, resonance detector 122 determines whether misfire resonance is detected (step S403). If the resonance detector 122 does not detect misfire resonance, the process proceeds to step S405. When the resonance detection unit 122 detects the misfire resonance, the delay control unit 123 performs delay control to delay generation of generator torque more than usual (step S404).

Then, misfire detection unit 121 determines whether or not misfire is not detected (step S405). If the misfire detection unit 121 detects a misfire, the process proceeds to step S402. On the other hand, misfire detection unit 121 terminates the series of processes when no misfire is detected.

[Example of experimental results]
Next, an example of experimental results according to this embodiment will be described. FIG. 5 is an example of experimental results showing the relationship between delay control, engine speed, and transmission input torque. In FIG. 5, time t5 indicates the timing at which delay control of the generator torque is started. The waveform of the rotation speed of the engine shows a tendency of attenuation after time t5.

Also, although the transmission input torque fluctuates greatly until time t5, the fluctuations subside after time t5. That is, after time t5, the misfire resonance is suppressed. As described above, in this embodiment, it is possible to suppress the transmission input torque by performing the delay control of generator torque generation at the time of misfire resonance.

As described above, in the present embodiment, when the engine 110 rotates at a specific number of revolutions at the time of misfire, the delay control is performed to delay the generation of the generator torque. As a result, even if misfire resonance (resonance of the drive system at the time of misfire) occurs, the phase of the generator torque can be adjusted to an appropriate phase, so the misfire resonance can be suppressed. Therefore, it is possible to suppress an increase in the input torque to transmission 140 at the time of misfire. Therefore, it is possible to prevent the transmission 140 from being damaged.

Further, in this embodiment, when misfire resonance is detected at a specific engine speed at the time of misfire, delay control of generation of generator torque is performed. As a result, misfire resonance that has occurred can be suppressed.

Further, in the embodiment, the delay control unit 123 includes a communication delay time between the engine ECU 120 and the motor ECU 150, a phase delay time due to physical twist of the flywheel, and a delay for suppressing resonance at the time of a misfire. I tried to control the delay based on time. As a result, it is possible to suppress the occurrence of misfire resonance caused by the communication delay.

Further, in this embodiment, the delay control unit 123 is provided in the engine ECU 120 or the motor ECU 150 . As a result, misfire resonance can be suppressed without adding a new component having the function of the delay control unit 123 .

As described above, the mode for carrying out the present invention has been described using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and replacements can be made without departing from the scope of the present invention. can be added.

REFERENCE SIGNS LIST 100 drive system 110 engine 120 engine ECU 130 flywheel 140 transmission 150 motor ECU 160 PDU 170 generator 121 misfire detector 122 resonance detector 123 Delay controller

Claims (7)

an engine having an output shaft for outputting power;
a torsion portion that applies a torsion moment to the output shaft;
a rotating electrical machine that is connected to the output shaft via the twisted portion and generates torque for power generation;
a delay control unit that performs delay control to delay the generation of the torque when the engine rotates at a specific speed when the engine misfires;
vehicle equipped with A detection unit that detects resonance of the output shaft caused by the torsional moment,
The delay control unit performs the delay control when the resonance is detected by the detection unit.
A vehicle according to claim 1 . an engine control unit that controls the engine;
a rotating electrical machine control unit that controls the rotating electrical machine based on instructions received from the engine control unit;
with
The delay control section controls a communication delay time between the engine control unit and the rotating electrical machine control unit, a phase delay time due to physical twist of the flywheel, and a delay time for suppressing resonance at the time of a misfire. and performing the delay control based on
A vehicle according to claim 1 or 2. The delay control unit is provided in either one of the engine control unit and the rotating electric machine control unit,
A vehicle according to claim 3. An engine having an output shaft that outputs power, a torsion section that applies a torsion moment to the output shaft, and a rotating electric machine that is connected to the output shaft via the torsion section and generates torque for power generation. A control device for use in a vehicle equipped with
a delay control unit that performs delay control to delay the generation of the torque when the engine rotates at a specific speed when the engine misfires;
A control device comprising: An engine having an output shaft that outputs power, a torsion section that applies a torsion moment to the output shaft, and a rotating electric machine that is connected to the output shaft via the torsion section and generates torque for power generation. A computer used in a vehicle equipped with
performing delay control to delay generation of the torque when the engine rotates at a specific speed when the engine misfires;
control method. An engine having an output shaft that outputs power, a torsion section that applies a torsion moment to the output shaft, and a rotating electric machine that is connected to the output shaft via the torsion section and generates torque for power generation. A computer used in a vehicle equipped with
detecting resonance of the output shaft caused by the torsional moment when the engine rotates at a specific speed when the engine misfires;
When the resonance is detected, delay control is performed to delay the generation of the torque;
program.

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