JP7707971B2 - Vehicle Control Method - Google Patents

Description

This disclosure relates to a vehicle control method.

In recent years, internal combustion engines and motors have come to be used as power sources for vehicles, and hybrid vehicles that use both an internal combustion engine and a motor as power sources are known.

When a vehicle is traveling, it may produce a booming sound. Specifically, a vehicle is made up of elastic bodies, and when a time-varying torque is applied to each component or the system to which they are connected, torsional vibration occurs. When the torque frequency matches the torsional resonance frequency, the amplitude of the torsional vibration increases, causing noise and other issues.

Patent Document 1 discloses a technique for reducing this torsional vibration, in which a damper torque calculated from the crank angle and input shaft angle is output in reverse phase by a motor, thereby performing control to reduce torque fluctuations.

JP 2017-100580 A

The control method disclosed in Patent Document 1 requires the motor to output torque, and so there is a problem in that fuel efficiency decreases if torque for vibration control continues to be output when the vehicle does not require vibration control.

This disclosure has been made in consideration of the problems described above, and provides a vehicle control method that improves fuel efficiency by implementing vibration damping control only when the vehicle requires vibration damping control.

The vehicle control method disclosed herein is a control method for a hybrid vehicle that performs vibration control to remove vibrations by applying a torque in the opposite phase to the damper torque to the motor, and when the engine is rotated at a predetermined rotation speed, it determines whether the difference between the engine torque at which a predetermined vibration occurs when vibration control is performed and the engine torque at which a predetermined vibration occurs when vibration control is not performed is greater than or equal to a predetermined value, and executes vibration control if the difference is greater than or equal to the predetermined value.
This makes it possible to determine whether or not to execute vibration suppression control based on the difference between the engine torque that generates vibration when vibration suppression control is executed and the engine torque that generates vibration when vibration suppression control is not executed.

Furthermore, the vehicle control method according to the present disclosure sets, as a region in which vibration damping control is performed, a region in which the difference between the engine torque at which a predetermined vibration occurs when the vibration damping control is performed and the engine torque at which a predetermined vibration occurs when the vibration damping control is not performed is equal to or greater than a predetermined torque, and the engine torque is equal to or less than the engine torque at which a predetermined vibration occurs when the vibration damping control is performed and equal to or greater than the engine torque at which a predetermined vibration occurs when the vibration damping control is not performed, and in the region in which vibration damping control is performed, a battery output required for vibration damping control is calculated using the engine speed and the value of the vibration damping torque generated when performing vibration damping, and reserves the calculated battery output required for vibration damping control before performing the vibration damping control.
This makes it easier to execute vibration damping control when it is necessary.

Furthermore, in the vehicle control method according to the present disclosure, when the battery output required for the vibration damping control cannot be reserved, the engine speed is increased until conditions are met for not executing the vibration damping control.
This allows vibration suppression to be achieved without relying on the battery output when the battery output cannot be secured.

This allows for improved fuel economy while still implementing vehicle vibration damping control.

FIG. 2 is a diagram showing an example of a connection related to the power of a vehicle according to the first embodiment. FIG. 2 is a diagram showing an example of a configuration for vehicle operation control according to the first embodiment; 4 is a diagram showing an example of an NV line and a vibration control ON line according to the first embodiment. FIG. 4 is a flowchart showing an example of a procedure of vibration suppression control according to the first embodiment. 13 is a flowchart showing an example of a procedure of vibration damping control according to the second embodiment. 13 is a diagram showing an example of an NV line, a vibration control ON line, and a vibration control region according to the second embodiment. FIG. FIG. 11 is a diagram showing an image of a battery output reserve according to the second embodiment. 13 is a flowchart showing an example of a procedure for suppressing deterioration of NV performance by increasing the minimum engine speed according to the third embodiment. 13 is a diagram showing the minimum rotation speed during normal operation according to the third embodiment, and a state in which the minimum rotation speed is increased when the maximum battery output required for vibration suppression control cannot be reserved. FIG.

First embodiment
Hereinafter, a vehicle control method according to a first embodiment will be described with reference to the drawings. Here, the vehicle will be described as a hybrid vehicle. Fig. 1 is a diagram showing an example of connections related to the power of the vehicle.

The vehicle 1 includes an internal combustion engine (hereinafter, engine) 11, a motor 12, a conversion unit 13, and wheels 14. The vehicle 1 also includes a damper 21 that connects the engine 11 and the motor 12, an input shaft 22 that connects the motor 12 and the conversion unit 13, and a drive shaft 23 that connects the conversion unit 13 and the wheels 14.

As shown in FIG. 2, the vehicle 1 has a configuration related to vehicle operation control. Specifically, the vehicle 1 includes a storage unit 31 that stores information such as an upper limit of NV (Noise Vibration) performance when vibration suppression control is performed and when vibration suppression control is not performed, a calculation unit 32, a determination unit 33 that determines whether or not vibration suppression control is performed, and a control unit 34 that causes the motor 12 to perform vibration suppression control according to the determination of the determination unit 33.

The engine 11 is typically a gasoline engine that compresses a mixture of gasoline and air, then ignites, burns, and expands it, outputting kinetic energy and generating torque.

The motor 12 generates torque using electricity stored in a battery housed in the vehicle 1. In response to control from the control unit 34, the motor 12 generates a vibration damping torque that is in the opposite phase to the damper torque applied from the engine 11 to the damper 21. In other words, the vibration damping torque is a torque that is generated to perform vibration damping.

Here, the battery power is used to generate power for the motor 12 to rotate the wheels 14, to cause the motor 12 to perform vibration damping control, and to operate electrical equipment within the vehicle.

The conversion unit 13 converts the power input from the power source, the engine 11 or the motor 12, via the input shaft 22 so that the wheels 14 operate appropriately according to the driving conditions of the vehicle 1.

Typically, the conversion unit 13 has a transmission and a differential gear. The transmission is made up of gears and shafts, and transmits the power of the power source to the shaft while changing the torque, rotation speed, and rotation direction. The differential gear is a differential device that converts the power to absorb the difference in rotation between the left and right wheels depending on the road conditions and driving conditions, such as when the vehicle 1 is turning a corner.

The wheels 14 rotate by receiving the force converted by the conversion unit 13 via the drive shaft 23. This allows the vehicle 1 to move.

The memory unit 31 stores NV (Noise Vibration) performance with and without vibration suppression control. For example, the memory unit 31 stores the contents shown in FIG. 3.

Figure 3 shows an NV line with vibration suppression that indicates the state in which the engine torque value that is the upper limit for NV performance changes when the engine speed is changed with vibration suppression control always on for a specified gear stage in vehicle 1, an NV line without vibration suppression that indicates the state in which the engine torque value that is the upper limit for NV performance changes when the engine speed is changed with vibration suppression control always off, and an NV line that indicates the NV performance that is acceptable for this vehicle 1.

In other words, each NV line shown in Figure 3 is a line that indicates the upper limit of engine torque allowed for each engine speed, based on the fact that NV performance deteriorates when a large engine torque is generated for a given engine speed, and NV performance improves when the engine torque is reduced.

Furthermore, FIG. 3 shows a vibration damping ON line that is the criterion for determining whether or not to perform vibration damping control in the motor 12. Note that below, a state in which vibration damping control is performed may be described as a state in which vibration damping control is ON, and a state in which vibration damping control is not performed may be described as a state in which vibration damping control is OFF. The vibration damping ON line will be described in detail later.

The calculation unit 32 can perform calculations to convert information so that a judgment can be made in the judgment unit 33, for example, based on the information stored in the memory unit 31.

The determination unit 33 determines whether or not to cause the motor 12 to perform vibration suppression control. Specifically, the determination unit 33 determines to perform vibration suppression control when the difference between the NV line with vibration suppression control and the NV line without vibration suppression control in FIG. 3 is greater than a predetermined value. In other words, the determination unit 33 determines to perform vibration suppression control at a point in FIG. 3 where these two lines are widely separated vertically.

On the other hand, the judgment unit 33 judges not to execute vibration suppression control when the difference between the NV line when vibration suppression control is applied and the NV line when vibration suppression control is not applied is equal to or less than a predetermined value.

That is, the determination unit 33 determines whether or not the difference between the engine torque at which a predetermined vibration occurs when vibration damping control is implemented and the engine torque at which a predetermined vibration occurs when vibration damping control is not implemented is equal to or greater than a predetermined value when the engine is rotated at a predetermined rotation speed. Here, the predetermined vibration is the upper limit of vibration that can be tolerated in the vehicle 1. In addition, the predetermined value can be any value, but is typically the upper limit of the vibration damping torque described below.

The control unit 34 controls the motor 12 to change the implementation state of vibration damping control according to the judgment result of the judgment unit 33. Here, the control unit 34 executes vibration damping control with at least one condition being whether or not the difference between the engine torque at which a predetermined vibration occurs when the vibration damping control judged by the judgment unit 33 is implemented and the engine torque at which a predetermined vibration occurs when the vibration damping control is not implemented is equal to or greater than a predetermined value.

As described below, the control unit 34 can also control the battery output to operate the motor 12 and the power to operate other power systems, etc.

In the following, the vehicle 1 will be described as having sensors capable of acquiring engine speed and engine torque values, and acquiring these sensor values as appropriate.

Here, an example of the vibration damping control procedure in vehicle 1 will be described with reference to the flowchart shown in FIG.

The upper limit of the damping torque generated by the motor 12 for vibration control is set to a value that does not significantly affect the performance of the vehicle power, etc., by generating the damping torque. For example, the upper limit of the damping torque is defined as 30 Nm.

The determination unit 33 determines whether the current engine speed and engine torque of the vehicle 1 obtained are equal to or higher than the vibration damping ON line on the two-dimensional graph shown in Figure 3 (step S11). Here, the determination by the determination unit 33 will be explained by explaining Figure 3 in more detail.

As shown in FIG. 3, in the NV line with vibration suppression, when the engine speed is lower than R1 and reaches R1, the engine torque value increases as the engine speed increases. In the NV line with vibration suppression, the engine torque value remains almost constant when the engine speed is increased from R1 to R3. When the engine speed is further increased and becomes higher than R3, the engine torque value also increases as the engine speed increases.

On the other hand, in the non-vibration damping NV line, when the engine speed is lower than R1 and reaches R2, the engine torque value increases as the engine speed increases. Note that R2 is higher than R1. In this case, the non-vibration damping NV line shows that when the engine speed is increased from R1 to R4, the engine torque value remains almost constant. R4 is slightly higher than R3. When the engine speed is further increased and reaches a value higher than R4, the engine torque value also increases as the engine speed increases.

Here, we will explain the difference in engine torque value at engine speed for the NV line with vibration suppression and the NV line without vibration suppression in Figure 3. As shown in Figure 3, the NV line with vibration suppression is always higher than the NV line without vibration suppression. In other words, with vibration suppression, the upper limit of engine torque in terms of NV performance that is allowable is higher than when there is no vibration suppression at the same engine speed.

From a state where the engine speed is lower than R1 up to R1, the NV line with vibration suppression has a higher engine torque value as the engine speed increases. Similarly, the NV line without vibration suppression has a higher engine torque value as the engine speed increases. As shown in Figure 3, in this section, the NV line with vibration suppression and the NV line without vibration suppression are almost parallel.

In the section up to this rotation speed R1, the NV line with vibration suppression and the NV line without vibration suppression are significantly separated. In other words, at the same engine rotation speed, there is a large difference in the upper limit of engine torque in terms of NV performance between the case with vibration suppression and the case without vibration suppression.

From rotation speed R1 to rotation speed R2, the NV line with vibration suppression has an almost constant engine torque value even as the engine rotation speed increases, while the NV line without vibration suppression has an increased engine torque value as the engine rotation speed increases. In other words, from rotation speed R1 to rotation speed R2, with vibration suppression, the allowable engine torque is almost constant, but without vibration suppression, the allowable engine torque increases as the rotation speed increases. That is, in this section from rotation speed R1 to rotation speed R2, the NV line without vibration suppression gradually approaches the NV line with vibration suppression as the rotation speed increases.

From rotation speed R2 to rotation speed R3, the engine torque value is almost constant on the NV line with vibration suppression. On the other hand, the engine torque value is also almost constant on the NV line without vibration suppression. In other words, in the section from rotation speed R2 to rotation speed R3, the allowable engine torque is almost constant regardless of the rotation speed, whether with or without vibration suppression. At this time, the NV line with vibration suppression and the NV line without vibration suppression are almost parallel and close to each other.

From RPM R3 to RPM R4, the engine torque value increases as the engine speed increases on the NV line with vibration suppression, while the engine torque value remains almost constant on the NV line without vibration suppression even as the engine speed increases. Here, because the difference between RPM R3 and R4 is small, the NV line with vibration suppression and the NV line without vibration suppression remain close to each other even as the engine speed increases.

When the engine speed is higher than R4, the NV line with vibration suppression and the NV line without vibration suppression both have higher engine torque values as the engine speed increases. As shown in Figure 3, in this section, the NV line with vibration suppression and the NV line without vibration suppression are nearly parallel, and the NV line with vibration suppression and the NV line without vibration suppression remain close to each other.

Next, we will explain the vehicle's NV line, which is the upper limit line for the vehicle's NV performance. As shown in Figure 3, when the engine speed is lower than R2, the NV line is set slightly above the NV line with vibration suppression, and when the engine speed is equal to or higher than R2, the NV line is set slightly above the NV line without vibration suppression.

At this time, the region where the engine speed is lower than R2 is the region where the vehicle's NV line is above the NV line with vibration suppression and the NV line without vibration suppression. In other words, this region is the region where the NV line is above the upper limit of the vibration suppression torque.

On the other hand, in the region where the engine speed is equal to or higher than R2, the vehicle's NV line is higher than the NV line without vibration suppression, but lower than the NV line with vibration suppression. In other words, this is the region where the vehicle's NV line is equal to or lower than the upper limit of the vibration suppression torque.

As shown in FIG. 3, the vibration damping ON line that determines whether or not to turn on vibration damping is set as follows. In vehicle 1, vibration damping control is performed when the engine speed and engine torque output shown in FIG. 3 are equal to or higher than the vibration damping ON line.

More specifically, the vibration suppression ON line is set slightly below the non-vibration suppression NV line in the region where the engine speed is lower than R2. This region where the engine speed is lower than R2 is the region where there is a large deviation between the vibration suppression NV line and the non-vibration suppression NV line.

Also, as shown in FIG. 3, when the engine speed is equal to or greater than R2, the vibration control ON line is set to an infinitely higher position. In other words, when the engine speed is equal to or greater than R2, the vibration control ON line is set to be determined to be below the vibration control ON line, regardless of the engine speed and engine torque.

If the determination unit 33 determines that the engine speed and engine torque of the vehicle are equal to or higher than the vibration damping ON line in FIG. 3 (Yes in step S11), the control unit 34 executes vibration damping control (step S12). That is, the control unit 34 turns on the vibration damping control of the motor 12.

On the other hand, if the determination unit 33 determines that the engine speed and engine torque of the vehicle are lower than the vibration damping ON line in FIG. 3 (No in step S11), the vibration damping control is not executed (step S13). In other words, the control unit 34 sets the vibration damping control of the motor 12 to the OFF state.

This allows vibration damping control to be turned off as long as the vehicle's NV performance is satisfied without vibration damping.

On the other hand, in the range where the vehicle's NV performance cannot be satisfied without vibration damping, but can be satisfied with vibration damping, vibration damping control can be turned ON. Specifically, in vehicle 1, in the range where the difference between the NV lines with and without vibration damping is equal to or greater than the vibration damping torque upper limit, that is, in the region where the engine speed described above is lower than speed R2, vibration damping control can be turned ON when the engine torque exceeds the NV line without vibration damping.

Therefore, in vehicle 1, a vibration damping ON line is set on a two-dimensional graph showing the relationship between engine speed and engine torque, and vibration damping control can be executed when the engine torque is equal to or greater than the vibration damping ON line. In this case, in vehicle 1, if the difference between the NV line with vibration damping and the NV line without vibration damping is large, it is advantageous in terms of energy management to raise the NV line with vibration damping, so efficiency can be improved by executing vibration damping control.

On the other hand, in vehicle 1, when the difference between the NV line with vibration suppression and the NV line without vibration suppression is small and the difference is less than 30 Nm, which is the upper limit of the vibration suppression torque, it is considered to be advantageous in terms of energy management not to implement the muffled vibration suppression, so it is possible to control so that vibration suppression control is not executed. This allows vehicle 1 to efficiently use the battery power used for vibration suppression control.

Embodiment 2
In the first embodiment, a description has been given of vibration suppression by outputting a torque in the opposite phase to the damper torque by the motor. However, since it is necessary to output torque from the motor, if the output is taken away by other control and if the motor cannot generate torque, it is considered that the NV performance of the vehicle will deteriorate.

Therefore, in the region where vibration control is performed, we will explain a method of reserving the battery output required for the motor to generate torque for vibration control, and calculating the upper limit of the system torque that can be used for power, etc., to prevent the deterioration of the vehicle's NV performance.

In addition, in the second embodiment, a vehicle having a similar configuration to the vehicle 1 described in the first embodiment is used, so the components are given the same reference numerals and the description is omitted.

Now, referring to Figure 5, we will explain an example of a procedure for determining whether vibration control is necessary and reserving battery output for vibration control if vibration control is necessary.

The determination unit 33 determines whether the current engine speed and engine torque of the vehicle 1 are within the vibration control region (step S21).

Here, the vibration suppression region will be explained. FIG. 6 shows the NV line with vibration suppression, which shows the state where the engine torque value that is the upper limit in terms of NV performance changes when the engine speed is changed with vibration suppression control always on, the NV line without vibration suppression, which shows the state where the engine torque value that is the upper limit in terms of NV performance changes when the engine speed is changed with vibration suppression control always off, and the NV line that is permissible for this vehicle 1, as well as the set vibration suppression region. Here, the NV line with vibration suppression, the NV line without vibration suppression, the NV line, and the vibration suppression ON line are the same as those shown in FIG. 3, so their explanation will be omitted.

The vibration suppression region shown in Figure 6 is the region where the engine speed is lower than R2, and is sandwiched between the NV line with vibration suppression above and the NV line without vibration suppression below.

In other words, the vibration suppression region is a region of engine speeds where the difference between the engine torque at which a certain vibration occurs when vibration suppression control is implemented and the engine torque at which a certain vibration occurs when vibration suppression control is not implemented is equal to or greater than a certain value. That is, the range of the horizontal axis set as the vibration suppression region in FIG. 6 is the range where the difference between the NV line with vibration suppression and the NV line without vibration suppression is large on the vertical axis, and in this case is a range lower than the rotation speed R2.

Furthermore, the vibration suppression region is a region that is equal to or lower than the engine torque at which a predetermined vibration occurs when vibration suppression control is implemented, and is equal to or higher than the engine torque at which a predetermined vibration occurs when vibration suppression control is not implemented. That is, the range of the vertical axis set as the vibration suppression region in FIG. 6 has an upper limit of the NV line with vibration suppression and a lower limit of the NV line without vibration suppression.

If the engine speed and engine torque of vehicle 1 are within the vibration suppression region (Yes in step S21), vehicle 1 calculates the battery output to be reserved for performing anti-vibration control by motor 12 (step S22).

Here, the calculation unit 32 calculates the magnitude of the battery output to be reserved using the engine speed and the upper limit of the vibration damping torque generated when performing vibration damping. More specifically, the calculation unit 32 calculates the value of the battery output for generating torque for vibration damping control in the motor 12 based on the fact that the engine speed and engine torque are within the vibration damping region and the upper limit of the vibration damping torque.

Here, Figure 7 is a diagram showing an image of reserving battery output. As shown in Figure 7, the battery output required for the motor to execute vibration suppression control takes the form of a sine wave in which the output alternately increases on the Win side and the Wout side over time. Therefore, in step S22, the value of the battery output to be reserved is calculated so as to cover the magnitude of both amplitudes on both the Win side and the Wout side of the battery as shown in Figure 7. Then, proceed to step S23.

If the engine speed and engine torque of vehicle 1 are not in the vibration suppression region (No in step S21), proceed to step S23.

The calculation unit 32 calculates the upper limit of the battery output that can be used for power, etc. (step S23). That is, when the calculation unit 32 calculates the battery output to be reserved for vibration control in step S22, it calculates the upper limit of the battery output that can be used for power, etc. by subtracting the reserved output from the total output. On the other hand, when the calculation unit 32 does not calculate the battery output to be reserved for vibration control, it calculates the upper limit of the battery output assuming that there is no battery output to be reserved.

The control unit 34 controls the vehicle within a range that does not exceed the upper limit of the available battery output calculated in step S23 (step S24). That is, when the control unit 34 needs to reserve the battery output for vibration control, it performs the reserve, so that the upper limit of the battery output that can be used for power and other electronic devices is lower than when the reserve is not needed.

This allows the battery output necessary for vibration suppression to be reserved in the region where vibration suppression control is implemented. Whether or not to reserve battery output is changed depending on whether the state of vehicle 1 is in the region where vibration suppression control is implemented, so battery output can be used efficiently.

Embodiment 3
In the second embodiment, the battery output is reserved to cover the amplitude of both the Win and Wout sides of the battery when the vibration control is performed in the vibration control region. However, in a low temperature or low charge state, when Win and Wout are both restricted and the required output cannot be reserved, the muffled vibration control cannot be performed, and the NV performance of the vehicle may deteriorate.

Therefore, in the third embodiment, we will explain a method for preventing the vehicle's NV performance from deteriorating by increasing the minimum engine speed when the battery output cannot be reserved to cause the motor 12 to generate the torque required for vibration control.

In addition, in the third embodiment, as in the second embodiment, a vehicle having a similar configuration to the vehicle 1 described in the first embodiment is used, and therefore the same reference numerals are used for each component, and the description thereof is omitted. The NV line with vibration suppression, the NV line without vibration suppression, the NV line, and the vibration suppression ON line shown in FIG. 9, which will be described later, are the same as those shown in FIG. 3, and therefore the description thereof is omitted.

Now, referring to Figure 8, we will explain the procedure for increasing the minimum engine speed to suppress deterioration of NV performance when power for vibration control cannot be reserved.

The calculation unit 32 calculates the maximum battery output that is desired to be reserved for vibration damping control in the motor 12 in the current gear stage (step S31).

Here, the calculation unit 32 calculates the maximum battery output to be reserved for vibration damping control by the motor 12 from the engine speed, engine torque, and upper vibration damping torque limit.

The maximum battery output to be reserved is calculated to cover the amplitudes of both the Win and Wout sides of the battery, similar to step S22 in the second embodiment.

Next, vehicle 1 acquires both the current battery Win and Wout values (step S32). For example, the battery Win and Wout values are acquired using a sensor installed in vehicle 1.

The determination unit 33 compares the maximum battery output to be reserved calculated in step S31 with the current battery Win and Wout values obtained in step S32, and determines whether the maximum battery output to be reserved can be secured (step S33).

If the maximum battery output required for vibration control can be reserved (Yes in step S33), the battery output is reserved and the process ends.

If the maximum battery output required for vibration control cannot be reserved (No in step S33), the minimum engine speed in the current gear is increased (step S34).

Figure 9 shows the minimum rotation speed under normal conditions and the state in which the minimum rotation speed is raised when the maximum battery output required for vibration control cannot be reserved. As shown in Figure 9, the minimum rotation speed under normal conditions is lower than rotation speed R1. And, when the maximum battery output required for vibration control cannot be reserved, this minimum rotation speed can be raised to rotation speed R2.

Specifically, when a certain engine torque is generated in vehicle 1 between the normal minimum rotation speed and rotation speed R2, there are some points where the relationship between engine rotation speed and engine torque is above the no vibration suppression NV line shown in Figure 9. In this case, the NV performance of vehicle 1 is degraded.

Therefore, in vehicle 1, the minimum rotation speed is increased to rotation speed R2. In other words, instead of generating a predetermined torque at a rotation speed lower than rotation speed R2 as would normally be the case, a similar torque is generated with the engine torque increased to rotation speed R2. As a result, the relationship between engine rotation speed and engine torque tends to be below the no vibration damping NV line shown in Figure 9, and vehicle 1 is in a good state in terms of NV performance.

Based on the above, when power for vibration damping control cannot be reserved, deterioration of NV performance can be suppressed by increasing the minimum engine speed until conditions are met for not executing vibration damping control.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the invention. In other words, the above description has been omitted or simplified as appropriate for the purpose of clarity, and a person skilled in the art can easily modify, add, or convert each element of the embodiment within the scope of the present invention.

In the first embodiment, it has been described that when the engine speed is lower than R2, vibration damping control may or may not be performed, and vibration damping control is not performed at speeds equal to or higher than R2, but this is not limited to the above. In other words, it is not necessary to use R2 as the threshold value, and for example, R1 to R2 can be used as the threshold value.

Similarly, in the second embodiment, the upper limit of the engine speed when the vibration damping region is set is set to speed R2, but this is not limited to this.

In addition, in the third embodiment, the minimum engine speed is increased to speed R2, but this is not limited to this. The minimum engine speed may be increased to the point where the vibration-free NV line shown in FIG. 9 rises sufficiently.

The contents described in the first, second, and third embodiments may be used in any combination.

REFERENCE SIGNS LIST 11: internal combustion engine 12: motor 13: conversion unit 14: wheel 21: damper 22: input shaft 23: drive shaft 31: memory unit 32: calculation unit 33: determination unit 34: control unit

Claims (2)

A control method for a hybrid vehicle that performs vibration suppression control to remove vibrations by applying a torque in opposite phase to the damper torque to the motor,
determining whether or not a difference between an engine torque at which a predetermined vibration occurs when vibration damping control is performed and an engine torque at which the predetermined vibration occurs when vibration damping control is not performed is equal to or greater than a predetermined value when the engine is rotated at a predetermined rotation speed;
When the difference is equal to or greater than a predetermined value, when vibration suppression control is executed,
The engine speed is
A region in which a difference between an engine torque at which a predetermined vibration occurs when the vibration damping control is performed and an engine torque at which a predetermined vibration occurs when the vibration damping control is not performed is equal to or greater than a predetermined torque, and
The engine torque is
a region where the vibration damping control is executed is set to be an engine torque region where the engine torque is equal to or lower than an engine torque where a predetermined vibration occurs when the vibration damping control is executed and is equal to or higher than an engine torque where the predetermined vibration occurs when the vibration damping control is not executed;
In the region where the vibration suppression control is performed,
Calculating the battery output required for vibration suppression control using the engine speed and the value of the vibration suppression torque generated when performing vibration suppression;
reserving the calculated battery output necessary for the vibration damping control before performing the vibration damping control;
How to control a vehicle. When the battery output necessary for the vibration damping control cannot be reserved, the engine speed is increased until a condition for not executing the vibration damping control is met.
The method for controlling a vehicle according to claim 1 .