JP7447720B2 - Engine control method and engine control device - Google Patents

Description

The present invention relates to an engine control method and an engine control device.

Patent Document 1 discloses a control device for a series hybrid vehicle that charges a battery with a generator using an engine as a drive source and supplies power from the battery to a drive motor for driving. Particularly, in this control method, in a region where the magnitude of road noise is lower than engine noise, the engine rotational speed is reduced to suppress the overall noise level of the vehicle.

Japanese Patent Application Publication No. 11-103501

However, simply reducing the engine rotational speed does not have a sufficient effect of suppressing the noise level, and may cause discomfort to vehicle occupants.

Therefore, an object of the present invention is to suppress discomfort to occupants due to noise caused by engine operation in a series hybrid vehicle.

According to an aspect of the present invention, in a series hybrid vehicle, the engine drives a generator to charge a battery and supply electric power to a drive motor for driving from the battery according to a required output, and the engine is started. An engine control method is provided that sets a starting threshold that is a threshold of the required output for causing the engine to start. This engine control method includes a background noise state determination step of determining whether the background noise of the vehicle is in a relatively high high background noise state or a relatively low background noise state; and a start/stop threshold setting step of setting a start threshold accordingly. In the start/stop threshold setting step, if it is determined that the background noise of the vehicle is in the high background noise state, the start threshold is set to a relatively small first start threshold, and the background noise of the vehicle is set to the relatively small first start threshold. When it is determined that the state is a low background noise state, the starting threshold is set to a relatively large second starting threshold. In addition, in the start/stop threshold setting process, if it is determined that the background noise of the vehicle is in a high background noise state, the stop threshold is set to a relatively small first stop threshold, and the background noise of the vehicle is low. If it is determined that there is a noise state, the stop threshold can be set to a relatively large second stop threshold.

According to the present invention, it is possible to suppress the discomfort caused to the occupant due to the noise accompanying the operation of the engine.

FIG. 1 is a diagram illustrating the configuration of a series hybrid vehicle in which an on-vehicle actuator control method according to an embodiment of the present invention is executed. FIG. 2 is a block diagram showing the functions of a controller that executes processing related to the in-vehicle actuator control method. FIG. 3 is a block diagram showing the functions of the road surface determination section. FIG. 4A is a flowchart illustrating zero-point calibration of the longitudinal G detection value in the slip determination process. FIG. 4B is a flowchart illustrating setting of a slip flag in the slip determination process. FIG. 4C is a diagram illustrating the interrelationship between the detected longitudinal G value, the estimated longitudinal G value, and the slip of the vehicle. FIG. 5 is a flowchart illustrating the estimated state determination process. FIG. 6A is a flowchart illustrating a process for setting a deactivation flag. FIG. 6B is a flowchart illustrating the process of clearing the deactivation flag. FIG. 7 is a flowchart illustrating the start flag setting process. FIG. 8 is a flowchart illustrating the stop flag setting process. FIG. 9 is a diagram illustrating an example of a map that defines the start threshold and the stop threshold. FIG. 10 is a diagram illustrating control results according to this embodiment.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a block diagram illustrating a configuration common to a series hybrid vehicle (hereinafter also simply referred to as "vehicle 100") to which an in-vehicle actuator control method (particularly an engine start/stop permission control method) according to the present embodiment is applied. It is.

As shown in FIG. 1, a vehicle 100 includes an engine (internal combustion engine) 1, a generator 2, a battery 3, an electric drive motor 4, a gear 5, an axle 6, wheels 7, and a controller 50. It is configured as a so-called series hybrid vehicle. That is, in the vehicle 100, the engine 1 drives the generator 2 to charge the battery 3 according to the required output P _r and supplies electric power from the battery 3 to the drive motor 4 for driving. In this embodiment, the on-vehicle actuators to be controlled include the engine 1, the generator 2, and the drive motor 4.

The engine 1 is mechanically connected to a generator 2 via a speed increaser (not shown), and the generator 2 is connected to a battery 3 so that power can be transmitted and received.

The drive motor 4 is mechanically connected to an axle 6 via a gear 5, and the axle 6 is mechanically connected to wheels 7. The driving force (or regenerative force) of the drive motor 4 is transmitted to the wheels 7 via the gear 5 and the axle 6. Therefore, the rotational speed of the wheels 7 (that is, the acceleration or deceleration of the vehicle 100) is adjusted by the driving force (or regenerative force) of the drive motor 4.

In particular, the vehicle 100 of this embodiment has a mechanical brake that brakes the vehicle 100 in response to an operation on a brake pedal mounted on the vehicle 100, and also includes a mechanical brake that brakes the vehicle 100 in response to an operation on a brake pedal mounted on the vehicle 100. A regenerative brake is installed that obtains braking force by regenerating the drive motor 4 according to the amount of reduction.

The controller 50 is a computer programmed to centralize control of the vehicle 100, including processing related to an engine control method as an in-vehicle actuator control method according to the present embodiment. More specifically, the controller 50 includes a hardware configuration consisting of a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input/output interface (I/O interface), and an in-vehicle actuator control method. It consists of a program for executing the processes that make up the system. Note that the controller 50 may be realized by implementing the above program on one computer hardware, or may be realized by distributing and implementing the above program on a plurality of computer hardware. As a specific example, the functions of the controller 50 can be realized by various computers installed in the vehicle 100, such as a battery controller, a vehicle controller, and a motor controller.

The controller 50 executes the engine control method described above by inputting various parameters received from various sensors or other controllers (not shown). Specifically, the controller 50 detects a detected value of the state of charge (SOC) of the battery 3 (hereinafter also referred to as "battery SOC") and a detected value of the rotational speed of the wheels 7 (hereinafter referred to as "wheel speed w"). ), detection value of the steering angle for the steering mounted on the vehicle 100 (hereinafter also referred to as "steering angle θ"), detection of longitudinal G (ratio of acceleration in the forward direction or backward direction of the vehicle 100 to gravitational acceleration) value (hereinafter also referred to as "longitudinal G detection value"), a flag indicating the operation of the stability control system (VDC: Vehicle Dynamics Control) (hereinafter also referred to as "VDC operation flag f _vdc "), TCS (Traction Control System) A flag indicating the operation of the ABS (Anti-lock Brake System) (hereinafter also referred to as the "ABS operation flag f _abs "), a flag indicating the operation of the ABS (Anti-lock Brake System) (hereinafter also referred to as the "TCS operation flag f _tcs "), a CAN (Controller Area Network) communication effectiveness (hereinafter also referred to as "CAN effective flag f _can "), a flag indicating that the mechanical brake mounted on the vehicle 100 is being operated (brake pedal operation) ( The estimated value of the rotation speed of the drive motor ₄ (hereinafter also referred to as the "motor rotation speed N _m "), and the operation amount for the accelerator pedal mounted on the vehicle 100 (hereinafter also referred to as "brake pedal operation flag f b "), (hereinafter also referred to as "accelerator opening degree APO") is acquired as an input.

Note that in this embodiment, the accelerator opening degree APO defines the magnitude of the output (mainly power consumed by running the vehicle 100) required of the vehicle 100 (particularly the drive motor 4). In particular, in this embodiment, the controller 50 executes power running control that requests positive driving force from the drive motor 4 when the accelerator opening degree APO is greater than or equal to a predetermined value, and when the accelerator opening degree APO is less than the predetermined value, the controller 50 regenerative control that requires negative driving force (i.e., regenerative braking force) to be performed. That is, when the accelerator opening degree APO is greater than or equal to the predetermined value, the output required from the vehicle 100 is a positive value, and when the accelerator opening degree APO is less than the predetermined value, the output required from the vehicle 100 is a negative value. becomes. In the following description, from the viewpoint of simplifying the description, the output (positive value or negative value) required of this vehicle 100 will be referred to as "required output P _r ".

FIG. 2 is a block diagram illustrating the functions of the controller 50. As illustrated, the controller 50 includes a vehicle speed calculation section 20, a target driving force calculation section 22, a road surface determination section 24, a sound vibration start determination section 26, a start/stop flag setting section 27, and a target power generation operating point. A setting section 28 is provided.

The vehicle speed calculation unit 20 calculates the vehicle speed v of the vehicle 100 based on the motor rotation speed N _m . The vehicle speed calculation unit 20 outputs the calculated vehicle speed v to the target driving force calculation unit 22 and the road surface determination unit 24.

The target driving force calculation unit 22 calculates a target value of driving force (hereinafter referred to as “target motor torque _T (also referred to as _"m "). The target driving force calculation unit 22 outputs the calculated target motor torque T _m to the road surface determination unit 24 and the drive motor 4 (motor inverter not shown in more detail).

The road surface determination unit 24 includes wheel speed w, steering angle θ, longitudinal G detected value, VDC operation flag f _vdc , TCS operation flag f _tcs , ABS operation flag f _abs , CAN valid flag f _can , brake pedal operation flag f _b , The road surface level Le is set based on the accelerator opening degree APO.

Here, the road surface level Le is a parameter that indexes the state of background noise of the vehicle 100 when the vehicle 100 is traveling. In particular, the road surface level Le is an estimated value (hereinafter also referred to as a "road noise value") that quantifies the degree of road surface roughness calculated from the wheel speed w (more specifically, the angular acceleration A described later), and It is set as a parameter indicating whether or not the estimated state of the road noise value is an appropriate estimated state. More specifically, the road surface level Le of this embodiment is "0", which corresponds to a case where the estimation state of the road noise value is not an appropriate estimation state, and "1", which is obtained by leveling the magnitude of the road noise value in each predetermined step. ” to “4”. In particular, in this embodiment, the magnitude of the road surface level Le is used as an index for estimating whether the background noise of the vehicle 100 is relatively large or small. More specifically, when the road surface level Le is "0" to "2", the background noise state is estimated to be a low background noise state, and when the road surface level Le is "3" to "4", the background noise state is estimated to be a low background noise state. The state is estimated to be a high background noise state.

Below, details of the process related to the setting of the road surface level Le by the road surface determination section 24 will be explained.

FIG. 3 is a block diagram showing the functions of the road surface determining section 24. As shown in FIG. As illustrated, the road surface determination section 24 includes an angular acceleration variance value calculation section 241, a slip determination section 242, an estimated state determination section 243, a variance value correction section 244, and a road surface level setting section 245.

The angular acceleration variance calculation unit 241 calculates the variance of the angular acceleration A of the wheels 7 (hereinafter also referred to as "angular acceleration variance var_A") based on the wheel speed w. Specifically, the angular acceleration variance calculation unit 241 calculates the angular acceleration A by calculating the first time differential with respect to the wheel speed w. Then, the angular acceleration variance value calculation unit 241 samples the angular acceleration A and sets the variance as the angular acceleration variance value var_A. Hereinafter, this variance value will also be referred to as "angular acceleration variance value var_A."

Here, the angular acceleration variance value var_A represents the variation in the angular acceleration A, and is a parameter that correlates with the roughness of the road surface on which the vehicle 100 travels (road noise value). Therefore, the angular acceleration variance value var_A can be used as an index for estimating the magnitude of the road noise value that determines the road surface level Le. Note that instead of the angular acceleration variance value var_A, any statistical amount that correlates with the variation in the angular acceleration A, such as the standard deviation and the root mean square, may be calculated as the estimation index of the road noise value. Then, the angular acceleration variance value calculation unit 241 outputs the calculated angular acceleration variance value var_A to the variance value correction unit 244.

The slip determination unit 242 receives the vehicle speed v and the detected longitudinal G value from the vehicle speed calculation unit 20 as input, and executes a slip determination process. The slip determination process is performed by checking a slip flag f _sl that indicates that a slip of the vehicle 100 has occurred (or is predicted to occur) in a specific driving scene of the vehicle 100 (from a stop to a low-speed driving state immediately after starting). This is the process of setting. In particular, in this embodiment, the slip determination process is performed as one of the elements for determining whether the estimated state of the road noise value is an appropriate estimated state. In particular, the slip determination process detects the occurrence of slip to the extent that the estimation accuracy of the road noise value based on the angular acceleration variance value var_A is reduced, although the vehicle 100 has not reached the slip accompanied by the above-mentioned TCS or VDC operation. Performed from a perspective.

4A and 4B are flowcharts for explaining the slip determination process. In particular, FIG. 4A shows the flow of processing related to longitudinal G input adjustment, and FIG. 4B shows the flow of processing related to setting of the slip flag f _sl . Note that the processes shown in FIGS. 4A and 4B can be executed in parallel.

First, as shown in FIG. 4A, in step S110, the slip determination unit 242 determines whether the vehicle 100 is stopped. Specifically, the slip determination unit 242 counts the time during which the vehicle speed v continues to be 0 or substantially 0, and when the time reaches a predetermined stop determination reference time, the slip determination unit 242 determines that the vehicle 100 It is determined that the vehicle is parked. If the slip determination unit 242 determines that the vehicle 100 is not stopped, it ends this routine. On the other hand, if the slip determination unit 242 determines that the vehicle 100 is stopped, it executes the processing from step S120 onwards.

In step S120, the slip determination unit 242 performs zero-point calibration on the longitudinal G detection value. That is, the slip determination unit 242 calculates a difference obtained by subtracting 0 from the longitudinal G detection value obtained when the vehicle 100 is stopped, and stores it in the storage area. Then, the slip determination unit 242 obtains a value obtained by subtracting the above-mentioned difference from a detection value input from a G sensor (for example, a strain gauge type or a capacitance type), not shown, as a longitudinal G detection value at subsequent control timings.

As shown in FIG. 4B, in step S130, the slip determination unit 242 determines whether the vehicle 100 is in a low speed running state. Specifically, the slip determination unit 242 determines whether the vehicle speed v is equal to or less than a predetermined low speed determination threshold.

When the slip determining unit 242 determines that the vehicle 100 is not in a low speed running state, it sets the slip flag f _sl to "0" and ends this routine. On the other hand, if the slip determination unit 242 determines that the vehicle 100 is in a low speed running state, it executes the processing from step S140 onwards.

In step S140, the slip determination unit 242 calculates an estimated longitudinal G value from the vehicle speed v. Specifically, the slip determination unit 242 calculates the acceleration a by differentiating the vehicle speed v with respect to time, and calculates the longitudinal G estimated value from the acceleration a.

Then, in step S150, the slip determination unit 242 determines whether the difference between the longitudinal G detected value calibrated using the value at the time of stopping and the longitudinal G estimated value calculated from the vehicle speed v is larger than a predetermined reference value. Here, the predetermined reference value is such that the longitudinal G estimated value estimated from the vehicle speed v (corresponding to the actual rotation speed of the wheels 7) actually acts on the vehicle 100 to the extent that it can be determined that the vehicle 100 is slipping. It is set to a suitable value from the viewpoint of whether or not it is far from the longitudinal G detected value based on the inertial force.

FIG. 4C is a diagram illustrating the interrelationship between the detected longitudinal G value, the estimated longitudinal G value, and the slip of the vehicle 100. Note that the horizontal axis in the graph of FIG. 4C shows the longitudinal G estimated value (corresponding to the time differential value of the motor rotation speed N _m ), and the vertical axis shows the longitudinal G detected value. Further, a broken line L1 and a solid line L2 represent the relationship between the longitudinal G estimated value and the longitudinal G detected value when no slip occurs and when a slip occurs, respectively. Moreover, the dotted line L3 represents a straight line in which the longitudinal G estimated value and the longitudinal G detected value are the same.

As understood from FIG. 4C, when no slip occurs (broken line L1), the longitudinal G estimated value and the longitudinal G detected value are equal to each other. On the other hand, when a slip occurs, the rate of change in the rotational speed of the wheels 7 (the rate of change in the motor rotational speed _Nm ) deviates from the value based on the assumption that the grip state between the tires and the road surface is maintained. Therefore, when a slip occurs, the longitudinal G estimated value (solid line L2) determined based on the vehicle speed v calculated from the motor rotation speed N _m is the longitudinal G detected value detected by the G sensor (motor rotation speed N _m (detected value regardless of the value). Therefore, as described with reference to FIG. 4B, by referring to the mutual deviation between the longitudinal G estimated value and the longitudinal G detected value, it is possible to suitably detect a slip in the vehicle 100.

Then, the slip determination unit 242 sets the slip flag f _sl of the vehicle 100 to "1" when the determination result in step S150 is affirmative. On the other hand, if the determination result in step S150 is negative, the slip determination unit 242 sets the slip flag f _sl of the vehicle 100 to "0".

Returning to FIG. 3, the slip determination unit 242 outputs the set slip flag f _sl to the estimated state determination unit 243.

The estimated state determination unit 243 uses wheel speed w, vehicle speed v, target motor torque T _m , brake pedal operation flag f _b , accelerator opening APO, VDC operation flag f _vdc , TCS operation flag f _tcs , ABS operation flag f _abs , Using the CAN valid flag f _can and slip flag f _sl as input, an estimation state determination process is executed to determine whether or not the road noise value estimation state is a proper estimation state. In particular, in the estimation state determination process of this embodiment, the appropriate estimation flag f op is set to "1" when the estimation state of the road noise value is an appropriate estimation state, and the appropriate estimation flag f _op is set to "1" when the estimation state of the road noise value is not an appropriate estimation _state . is set to "0". The details of the estimated state determination process will be described below.

FIG. 5 is a flowchart illustrating the estimated state determination process.

As shown in the figure, first, in step S200, the estimated state determination unit 243 selects a brake pedal operation flag f _b , an accelerator off flag f _ac , a VDC operation flag f _vdc , a TCS operation flag f _tcs , and an ABS operation flag f _abs Determine whether all are set to "0". Note that the accelerator off flag f _ac is a flag that is set to "1" when it is determined that the accelerator pedal is not operated (driving force request to the vehicle 100). Specifically, the estimated state determining unit 243 sets the accelerator off flag f _ac to "1" when the accelerator opening APO is less than or equal to a predetermined value, and sets the accelerator off flag f ac to "1" when the accelerator opening APO exceeds the predetermined value. Set to "0".

If the estimated state determining unit 243 determines that at least one of these flag values is "1", the process proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. In other words, this applies when an operation on the brake pedal is detected, when an operation on the accelerator pedal is not detected, when VDC is activated, when TCS is activated, or when ABS is activated. Then, since it is assumed that the calculated value of the angular acceleration A contains an error, it will be determined that the estimated state of the road noise value is not appropriate.

On the other hand, if the estimated state determining unit 243 determines that all the flag values are "0" in the determination in step S200, it executes the process in step S210.

In step S210, the estimated state determination unit 243 determines whether the target motor torque T _m is greater than or equal to the first torque threshold T _{m_th1} and less than or equal to the second torque threshold T _{m_th2} . If the result of the determination is negative, the estimated state determining unit 243 proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. On the other hand, if the result of the determination is positive, the estimated state determination unit 243 executes the process of step S220.

Here, the first torque threshold T _{m_th1} and the second torque threshold T _{m_th2} are the lower limit and upper limit of the target motor torque T _m , respectively, which are determined from the viewpoint of ensuring estimation accuracy of the road noise value. Note that the first torque threshold T _{m_th1} and the second torque threshold T _{m_th2} may be set to fixed values determined experimentally in advance, or may be set to variable values that change depending on the driving state of the vehicle 100. Also good.

In particular, the first torque threshold T _{m_th1} and the second torque threshold T _{m_th2} may be variable values depending on the vehicle speed v. For example, if the determination result in step S210 is negative at a certain control timing, a different first torque threshold T _{m_th1} or second torque threshold T _{m_th2} may be used for the determination at a later control timing. good. That is, a predetermined hysteresis may be set for the first torque threshold T _{m_th1} and the second torque threshold T _{m_th2} .

Next, in step S220, the estimated state determination unit 243 determines whether the vehicle speed v is greater than or equal to the first vehicle speed threshold value _{v_th1} and less than or equal to the second vehicle speed threshold value _{v_th2} . If the result of the determination is negative, the estimated state determining unit 243 proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. On the other hand, if the result of the determination is positive, the estimated state determination unit 243 executes the process of step S230.

Here, the first vehicle speed threshold value v _{_th1} and the second vehicle speed threshold value v _{_th2} are the lower limit value and upper limit value of the vehicle speed v, respectively, which are determined from the viewpoint of ensuring estimation accuracy of the road noise value. Note that the first vehicle speed threshold v _{_th1} and the second vehicle speed threshold v _{_th2} may be set to fixed values determined experimentally in advance, or may be set to variable values that change depending on the driving state of the vehicle 100. Also good. In particular, a predetermined hysteresis may be set for the first vehicle speed threshold v _{_th1} and the second vehicle speed threshold v _{_th2} , similarly to the first torque threshold T _{m_th1} and the second torque threshold T _{m_th2} .

Next, in step S230, the estimated state determination unit 243 determines whether the slip flag f _sl set in the slip determination process is "0". If the determination result is negative, the estimated state determination unit 243 proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. That is, in this case, it is determined that the calculated value of the angular acceleration A for estimating the road noise value may include an error due to the slip of the vehicle 100. On the other hand, if the estimated state determining unit 243 determines that the slip flag f _sl is "0", it executes the process of step S240.

In step S240, the estimated state determination unit 243 determines whether the CAN validity flag f _can is "1". If the estimation state determination unit 243 determines that the CAN validity flag f _can is not "1", the process proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. In other words, in this case, it is assumed that the input parameters such as wheel speed w for calculating the angular acceleration A cannot be obtained normally, and it is determined that the estimation accuracy of the road noise value may decrease. . On the other hand, when the estimated state determining unit 243 determines that the CAN validity flag f _can is "1", it executes the process of step S250.

In step S250, the estimated state determination unit 243 determines whether the number of distributed samples is equal to or greater than a certain value. Specifically, the estimated state determination unit 243 uses the timing at which it is detected that all of the determination results in steps S200 to S250 are positive as a base point, and determines the timing from the viewpoint of suitably calculating the angular acceleration variance value var_A. It is determined whether a certain number of calculated values of angular acceleration A have been obtained.

If the estimation state determining unit 243 determines that the number of distributed samples is not equal to or greater than a certain value, the process proceeds to step S270, sets the appropriate estimation flag f _op to "0", and ends this routine. In other words, in this case, the number of input data (more specifically, the number of detected wheel speeds w) for determining the appropriate angular acceleration variance value var_A is insufficient from the viewpoint of ensuring the estimation accuracy of the road noise value. The appropriate estimation flag f _op is set to "0". On the other hand, if the estimated state determining unit 243 determines that the number of distributed samples is equal to or greater than the certain value, it executes the process of step S260. Note that in the determination in step S250, if the determination result is negative at a certain control timing, there is a delay that waits until the number of distributed samples is secured (that is, until the determination result becomes positive). Processing may be adopted.

If all of the determination results in steps S200 to S250 are positive, in step S260, the estimated state determining unit 243 sets the appropriate estimation flag f _op to "1" and ends this routine. That is, in this embodiment, when all the determination results in steps S200 to S250 are positive, it is determined that the estimation accuracy of the road noise value is secured above a certain level, and the appropriate estimation flag f _op is set to "1". ” will be set.

Returning to FIG. 3, the estimated state determination unit 243 outputs the set appropriate estimation flag f _op to the road surface level setting unit 245.

On the other hand, the variance value correction unit 244 inputs the vehicle speed v, the steering angle θ, and the angular acceleration variance value var_A, and corrects the angular acceleration variance value var_A. Specifically, the variance value correction unit 244 corrects the angular acceleration variance value var_A using a table that defines correction coefficients according to the vehicle speed v and the steering angle θ. In particular, in this embodiment, the correction is performed such that the larger the vehicle speed v or the steering angle θ is, the smaller the angular acceleration variance value var_A is. In addition, instead of or in addition to the correction of the angular acceleration variance value var_A based on the vehicle speed v and the steering angle θ, in the process of setting the road surface level Le in the road surface level setting unit 245, which will be described later, a comparison with the angular acceleration variance value var_A is performed. It is also possible to adopt a configuration in which the threshold value is corrected according to the vehicle speed v and the steering angle θ.

The significance of this correction will be explained. When the steering operation is being performed, the wheels 7 will slip slightly compared to when the steering operation is not being performed, so that when the wheels 7 go over a convex part on an uneven road surface, the wheels 7 may slip slightly. The variance of the angular acceleration A tends to be larger than expected. Therefore, when a steering operation is being performed, a correction is performed to reduce the angular acceleration variance value var_A in accordance with the magnitude of the vehicle speed v, from the viewpoint of maintaining the estimation accuracy of the road noise value. Then, the variance value correction unit 244 outputs the corrected angular acceleration variance value var_A_c to the road surface level setting unit 245.

The road surface level setting unit 245 receives the angular acceleration variance value var_A_c and the appropriate estimation flag f _op and sets the above-mentioned road surface level Le. In particular, when the appropriate estimation flag f _op is set to "0" (that is, when the road noise value estimation state is not the appropriate estimation state), the road surface level setting unit 245 sets the angular acceleration variance value var_A_c to Regardless, the road surface level Le is set to "0".

On the other hand, when the appropriate estimation flag f _op is set to "1" (when the road noise value estimation state is the appropriate estimation state), the road surface level setting unit 245 determines the road noise value (i.e., the angular acceleration The road surface level Le is set to "1" to "4" depending on the magnitude of the variance value var_A_c). More specifically, the road surface level setting unit 245 sets three threshold values for the angular acceleration variance value var_A_c, and sets the road surface level Le as " 1,” “2,” “3,” and “4,” respectively. Then, the road surface level setting section 245 outputs the set road surface level Le to the sound vibration start determination section 26.

In addition, in this embodiment, the case where the road surface level Le is set to "0", "1", or "2" corresponds to a low background noise state, and the case where it is set to "3" or "4" corresponds to a low background noise state. Corresponds to a high background noise condition.

Returning to FIG. 2, the sound vibration start determination unit 26 inputs the road surface level Le, the appropriate estimation flag f _op , and the vehicle speed v, and outputs a required output P _r for starting the engine 1 according to the magnitude of the road surface level Le. control (hereinafter referred to as " _{sound vibration start} (also referred to as "control") executes a sound vibration start determination process to determine whether to enable or not. In particular, in the estimated state determination process of this embodiment, the deactivation flag f _no is set to "0" when the sound vibration start determination process should be executed, and is set to "1" when it should not be executed. be done. The details of the sound vibration start determination process will be described below. Note that in this embodiment, when the vehicle 100 is started (when the ignition switch is turned on), the initial value of the deactivation flag f _no is set to either "0" or "1". Assumed.

6A and 6B are flowcharts illustrating the sound vibration start determination process. In particular, FIG. 6A is a flowchart illustrating the determination to set the deactivation flag f _no to "1" (deactivation flag setting determination) in order to invalidate the operation of the sound vibration start control. Further, FIG. 6B is a flowchart illustrating a determination to clear the deactivation flag f _no set based on the process of FIG. 6A (deactivation flag clear determination).

First, in the deactivation flag setting determination shown in FIG. 6A, in step S300, the sound vibration start determination unit 26 determines whether the appropriate estimation flag f _op is set to "1". Then, when the sound vibration start determination unit 26 determines that the appropriate estimation flag f _op is "1", it executes the processes from step S310 onwards.

In step S310, the sound vibration start determination unit 26 sets a control unit distance d _u . Here, the control unit distance d _u is the distance that the vehicle 100 travels during a preset calculation cycle Δt (for example, 10 ms). That is, the control unit distance d _u is defined as a value obtained by multiplying the vehicle speed v by the calculation period Δt, and is a variable amount depending on the magnitude of the vehicle speed v.

In step S320, the sound vibration start determination unit 26 calculates the road surface determination cumulative travel distance D. Specifically, first, the sound vibration start determination unit 26 acquires the total travel distance of the vehicle 100 from the time when the vehicle 100 is started (for example, the timing when the ignition switch is turned on) to the current control cycle. Then, the sound vibration start determination unit 26 determines the distance traveled by the vehicle 100 when the proper estimation _flag is set to "1" from the start of the vehicle 100 to the current control cycle. Calculate distance. More specifically, the sound vibration start determination unit 26 calculates the road surface determination cumulative travel distance D by multiplying the number of times of control for which the appropriate estimation flag f _op is set to "1" by the control unit distance d _u .

In step S330, the sound vibration start determination unit 26 calculates the cumulative travel distance D _ba on rough roads. Specifically, the sound vibration start determination unit 26 determines whether the appropriate estimation flag f _op is set to "1" and the road surface level Le is set to "3" or "4" from the start of the vehicle 100 to the current control cycle. By multiplying the set number of times of control by the control unit distance d _u , the cumulative rough road travel distance D _ba is obtained.

Then, in step S340, the sound vibration start determination unit 26 calculates the rough road continuation rate R _bc . Specifically, the sound vibration start determination unit 26 divides the rough road running cumulative distance D _ba by the road surface determination cumulative traveling distance D to obtain the rough road continuation rate R _bc .

Next, in step S350, the sound vibration start determination unit 26 determines that the rough road continuation rate R _bc is equal to or greater than a predetermined rough road continuation rate threshold R _{bc_th} while the vehicle 100 has traveled a predetermined specified travel distance _{D_th} . It is determined whether or not. Specifically, the sound vibration start determination unit 26 calculates the specified travel distance D _{_th} by multiplying the predetermined number of times of control by the control unit distance d _u . Then, the sound vibration start determination unit 26 determines whether or not the rough road continuation rate R _bc becomes equal to or greater than the rough road continuation rate threshold R _{bc_th} during the control cycle during driving for the specified travel distance D _{_th} . In addition, the bad road continuation rate threshold R _{bc_th} determines whether erroneous determination continues in determining whether the road the vehicle 100 is traveling on is a "bad road" or a "good road" (determination based on the road surface level Le). It is set to a suitable value from the viewpoint of determining whether or not the

In particular, the rough road continuation rate threshold R _{bc_th} is set from the viewpoint of determining whether or not the operation time of the engine 1 becomes longer and fuel efficiency decreases when the sound vibration start control is enabled. More specifically, a state in which the erroneous determination that the vehicle 100 is traveling on a "bad road" is maintained for a certain period of time or more and the operation of the sound vibration start control is enabled (the engine 1 is easily started or difficult to stop) It is assumed that if this condition continues, the battery SOC will rise and the engine 1 will be started and stopped frequently. Therefore, the rough road continuation rate threshold R _{bc_th} is set to a suitable value from the viewpoint of suppressing such a situation.

When the sound vibration start determination unit 26 determines that the rough road continuation rate R _bc is equal to or higher than the rough road continuation rate threshold R _{bc_th} over the specified travel distance _{D_th} , the process proceeds to step S360, and the deactivation flag f _no is set to "1" and this routine ends. That is, in this case, the sound vibration start control is invalidated. On the other hand, if the above determination result is negative, the sound vibration start determination unit 26 proceeds to step S370 and ends this routine while maintaining the deactivation flag f _no .

On the other hand, in step S300, if the sound vibration start determining unit 26 determines that the appropriate estimation flag f _op is not "1" (determining that it is "0"), the process proceeds to step S340. That is, in the current control cycle, if it is determined that the estimated state of the road noise value is not appropriate, the sound vibration start determination unit 26 calculates the road surface determination cumulative mileage D in step S320 and calculates the road surface determination cumulative travel distance D in step S330. The rough road continuation rate R _bc is calculated without calculating the cumulative travel distance D _ba .

As a result, if the vehicle 100 continues to travel while the road noise value estimation state is not appropriate, the distance related to the travel can be excluded from the calculation target of the road surface judgment cumulative travel distance D. It is possible to suppress a decrease in accuracy of the rough road continuation rate R _bc . More specifically, by adding the distance when the road noise value estimation state is not appropriate to the road surface judgment cumulative mileage D, the rough road continuation rate R _bc is calculated to be lower than the expected value, which may cause errors. A phenomenon in which the sound vibration start control is switched between activation and non-activation based on the determination is suppressed.

Note that the sound vibration start determination unit 26 resets the road surface determination cumulative travel distance D calculated in step S320 to 0 in the control cycle after the deactivation flag f _no is switched from "1" to "0". Preferably, the device is configured to do so. As a result, in a scene where the vehicle 100 travels a relatively long distance after starting, the road surface judgment accumulated mileage D becomes a large value, and the rough road judgment cumulative mileage D _ba is divided by the road surface judgment accumulated mileage D. The rate of change in the road continuation rate R _bc is suppressed from becoming small. As a result, the accuracy of misjudgment based on the rough road continuation rate R _bc can be further improved.

Next, the determination of clearing the deactivation flag shown in FIG. 6B will be explained.

First, in step S380, the sound vibration start determination unit 26 determines whether the deactivation flag f _no is set to "1". Then, when the sound vibration start determining unit 26 determines that the deactivation flag f _no is not "1" (determining that it is "0"), it ends this routine. On the other hand, if the sound vibration start determination unit 26 determines that the deactivation flag f _no is "1", it executes the processing from step S381 onwards.

In step S381, the sound vibration start determination unit 26 determines whether the good road continuation rate R _gc has become equal to or greater than a predetermined good road continuation rate threshold R _{gc_th} after the vehicle has traveled the specified travel distance D _{_th} . Specifically, the sound vibration start determination unit 26 calculates the specified travel distance D _{_th} using the same method as the process in step S350 described above. Then, the sound vibration start determination unit 26 determines whether or not the good road continuation rate R _gc becomes equal to or greater than the good road continuation rate threshold R _{gc_th} during the control cycle during driving for the specified travel distance D _{_th} .

Here, the good road continuation rate R _gc is a value obtained by dividing the cumulative travel distance D _gc on good roads by the road surface judgment cumulative travel distance D. Further, the cumulative distance traveled on a good road D _gc can be calculated by multiplying the number of times the road surface level Le is set to any one of "0" to "2" by the control unit distance d _u . Note that the good road continuation rate R _gc may be determined by subtracting the bad road continuation rate R _bc determined in step S340 from 1 (corresponding to the total road surface judgment cumulative travel distance D). Furthermore, the good road continuation rate threshold R _{gc_th} determines that the good road judgment based on the road surface level Le continues to the extent that the deactivation flag f _no can be cleared (that is, the bad road driving judgment based on the erroneous judgment is set to a suitable value from the viewpoint of determining that no

In particular, the good road continuation rate threshold R _{gc_th} is such that the deactivation flag f _no , which is set from the viewpoint of suppressing the sound vibration start control from being executed based on the bad road judgment based on the above-mentioned erroneous judgment, is set to "1" forever. '' is set to a suitable value from the viewpoint of suppressing a situation where the engine 1 does not operate even in a necessary scene.

Then, when the sound vibration start determination unit 26 determines that the good road continuation rate R _gc is equal to or higher than the good road continuation rate threshold R _{gc_th} over the specified mileage _{D_th} , the process proceeds to step S382, and the deactivation flag f _no is set to "0" and this routine ends. That is, in this case, the sound vibration start control is switched from an invalid state to an effective state. On the other hand, if the above determination result is negative, the sound vibration start determination unit 26 proceeds to step S383 and ends this routine while maintaining the deactivation flag f _no .

Returning to FIG. 2, the sound vibration start determination unit 26 outputs the set deactivation flag f _no to the start/stop flag setting unit 27.

The start/stop flag setting unit 27 inputs the battery SOC, the deactivation flag f _no , and the target motor torque T _m and sets the start flag f _st (normal start flag f _ust and rough road start) for starting the engine 1. Executes start/stop flag setting processing (start flag setting processing and stop flag setting processing) that sets the flag f _bst ) and the stop flag f _en (normal stop flag f _uen and rough road stop flag f _ben ) for stopping. do.

FIG. 7 is a flowchart illustrating the start flag setting process.

First, in steps S410 and S420, the start/stop flag setting unit 27 sets a normal start threshold P _{r_suth} and a rough road start threshold P _{r_sbth} .

Here, the normal start threshold P _{r_suth} defines the start timing determined from the viewpoint of operating the engine 1 at the most efficient operating point (an operating point close to the optimum fuel efficiency point) while maintaining the battery SOC within an appropriate range. It is set as the value of the requested output P _r . Therefore, the normal starting threshold P _{r_suth} of this embodiment is prepared in advance in the form of a map using the required output P _r , the vehicle speed v, and the battery SOC as variables.

On the other hand, the rough road starting threshold P _{r_sbth} defines the starting timing determined from the viewpoint of making it easier to start the engine 1 compared to the case where the normal starting threshold P _{r_suth} is set within a range where the battery SOC does not exceed the appropriate range. The value of the requested output P r is set as the value of the requested output P _r . That is, the rough road starting threshold P _{r_sbth} is set to a value less than or equal to the normal starting threshold P _{r_suth} and is prepared in advance in the form of a map using the required output P _r , vehicle speed v, and battery SOC as variables.

Next, in step S430, the start/stop flag setting unit 27 determines whether the deactivation flag f _no is "1". When the start/stop flag setting unit 27 determines that the deactivation flag f _no is "1" (when the sound vibration start control is disabled), the process proceeds to step S440.

In step S440, the start/stop flag setting unit 27 determines whether the requested output P _r is equal to or greater than the normal start threshold P _{r_suth} . When the start/stop flag setting unit 27 determines that the required output P _r is equal to or higher than the normal start threshold P _{r_suth} , the start/stop flag setting unit 27 sets the normal start flag f _ust as the start flag f _st in step S460, and ends this process. .

On the other hand, if the start/stop flag setting unit 27 determines that the deactivation flag f _no is "0" in step S430 (if the sound vibration start control is enabled), the process proceeds to step S450.

In step S450, the start/stop flag setting unit 27 determines whether the requested output P _r is equal to or greater than the rough road starting threshold P _{r_sbth} . When the start/stop flag setting unit 27 determines that the requested output P _r is equal to or greater than the rough road starting threshold P _{r_sbth} , the start/stop flag setting unit 27 sets the rough road starting flag f _bst as the starting flag f _st in step S470 and executes this process. finish.

According to the start flag setting process described above, when the sound _vibration start control is effective, _the start flag _{f st} (Rough road start flag f _bst ) will be set.

FIG. 8 is a flowchart illustrating the stop flag setting process.

First, in steps S510 and S520, the start/stop flag setting unit 27 sets a normal stop threshold P _{r_euth} and a rough road stop threshold P _{r_ebth} .

Here, the normal stop threshold P _{r_euth} is set as a value of the required output P _r that defines a stop timing that can sufficiently secure the battery SOC even if the engine 1 is stopped (stops power generation). The normal stop threshold P _{r_euth} is prepared in advance in the form of a map using the required output P _r , the vehicle speed v, and the battery SOC as variables.

On the other hand, the rough road stop threshold P _{r_ebth} is set as the value of the required output P _r that defines a stop timing that makes it more difficult to stop the engine 1 within a range where the battery SOC can be maintained within an appropriate range. That is, the rough road stopping threshold P _{r_ebth} is set to a value less than or equal to the normal stopping threshold P _{r_euth} and is prepared in advance in the form of a map using the required output P _r , vehicle speed v, and battery SOC as variables.

In step S530, the start/stop flag setting unit 27 determines whether the rough road start flag f _bst is set as the start flag f _st . If the start/stop flag setting unit 27 determines that the rough road start flag f _bst is set, the process proceeds to step S550, and if it determines that it is not set, the process proceeds to step S540.

In step S540, the start/stop flag setting unit 27 determines whether the vehicle 100 is currently traveling on a rough road. Specifically, the start/stop flag setting unit 27 determines that the vehicle is traveling on a rough road when the road surface level Le set at the current control timing is "3" or higher, and otherwise determines that the vehicle is traveling on a good road. Judging to be medium.

If the start/stop flag setting unit 27 determines that the vehicle 100 is currently traveling on a rough road, the process proceeds to step S550, whereas if it determines that the vehicle 100 is currently traveling on a good road, the process proceeds to step S560.

In step S550, the start/stop flag setting unit 27 determines whether the requested output P _r is less than or equal to the rough road stop threshold P _{r_ebth} . Then, when the start/stop flag setting unit 27 determines that the requested output P _r is equal to or less than the rough road stop threshold P _{r_ebth} , the start/stop flag setting unit 27 sets the rough road stop flag f _ben as the stop flag f _en (step S570), and this process end. On the other hand, if the start/stop flag setting unit 27 determines that the requested output P _r is not less than the rough road stop threshold P _{r_ebth} , it does not set the stop flag f _en and ends this process.

In step S560, the start/stop flag setting unit 27 determines whether the requested output P _r is less than or equal to the normal stop threshold P _{r_euth} . When the start/stop flag setting unit 27 determines that the requested output P _r is equal to or less than the normal stop threshold P _{r_euth} , the start/stop flag setting unit 27 sets the normal stop flag _{f uen as} the stop flag f en (step S580), and ends this process. do. On the other hand, if the start/stop flag setting unit 27 determines that the requested output P _r is not less than the normal stop threshold P _{r_euth} , it does not set the stop flag f _en and ends this process.

According to the stop flag setting process described above, when the rough road start flag f _bst is set as the start flag f _st (when the engine 1 starts at the rough road start threshold P _{r_sbth} ), the stop flag f _en is set as the start flag f st. A rough road stop flag f _ben is set (the engine 1 is stopped at the rough road stop threshold P _{r_ebth} ). On the other hand, when the normal start flag f _ust is set as the start flag f _st (when the engine 1 starts at the normal start threshold P _{r_suth} ), it is determined whether the road surface at the time of stopping is a "bad road" or a "good road". ”, a rough road stop flag f _ben or a normal stop flag f _uen is set.

FIG. 9 shows an example of a map that defines the normal starting threshold P _{r_suth} , the rough road starting threshold P _{r_sbth} , the normal stopping threshold P _{r_euth} , and the rough road stopping threshold P _{r_ebth} . According to the map shown in FIG. 9, the rough road starting threshold P _{r_sbth} is the rough road starting threshold P _{r_sbth} and _the rough road stopping threshold P _{r_ebth} is set to a value lower than the normal start threshold P _{r_suth} and the normal stop threshold P _{r_euth} . In particular, we focused on the SOC intermediate region where changes in battery SOC are easily tolerated (area where it is difficult to deviate from the appropriate range even if battery SOC changes), and set the rough road starting threshold P _{r_sbth} and the rough road stopping threshold P _{r_ebth} to the normal starting threshold. The rough road starting threshold P _{r_sbth} (rough road stopping threshold P _{r_ebth} ) and the normal starting threshold P _{r_suth} (normal stopping threshold P _{r_euth} ) are set to a value lower than P _{r_suth} and the normal stopping threshold P _{r_euth} in other SOC areas. It is preferable that they be set to substantially the same value. This suppresses overcharging or overdischarging of the battery 3 due to execution of the acoustic vibration start control, or frequent starting and stopping of the engine 1 due to battery SOC going back and forth within the appropriate range. be able to.

Further, the rough road starting threshold P _{r_sbth} and the normal starting threshold P _{r_suth} are set to take smaller values as the battery SOC is lower. Further, the rough road stop threshold P _{r_ebth} and the normal stop threshold P _{r_euth} are set to take larger values as the battery SOC becomes larger.

Returning to FIG. 2, the start/stop flag setting section 27 outputs the set start flag f _st and stop flag f _en to the target power generation operating point setting section 28 .

The target power generation operating point setting unit 28 sets the operating point of the engine 1 using the start flag f _st and the stop flag f _en as input. Specifically, the target power generation operating point setting unit 28 sets the fuel efficiency as much as possible within a range where the battery SOC can be maintained within an appropriate range, according to the start timing and stop timing of the engine 1 defined by the _start flag f st and the stop flag f _en . The target rotational speed N _e and target torque T _e of the engine 1 are set so as to improve the fuel efficiency (approach the optimum fuel efficiency point). Then, the target power generation operating point setting unit 28 sets the set target rotational speed N _e and target torque T _e of the engine 1 to the generator 2 (in particular, the inverter of the generator 2, not shown) and the engine 1 (particularly, the inverter, not shown), respectively. output to the engine control controller).

FIG. 10 is a diagram illustrating a control result obtained by applying the control method according to the present embodiment to a specific driving scene of the vehicle 100. FIG. 10(a) shows a section in which the sound vibration start control is effective. Moreover, FIG. 10(b) shows the change in battery SOC over time. Furthermore, FIG. 10(c) shows changes over time in the required output P _r , the start threshold P _{r_sth} , and the stop threshold P _{r_eth} . In particular, the rough road starting threshold P _{r_sbth} and the normal starting threshold P _{r_suth} are shown by a bold solid line and a bold broken line, respectively, and the rough road stopping threshold P _{r_ebth} and the normal stopping threshold P _{r_euth} are shown by a thin solid line and a thin broken line, respectively.

As shown in the figure, the sound vibration start control is effective because the vehicle continues to be traveling on a "good road" until time t1 (Yes in step S381 and step S382 in FIG. 6B). Then, at time t1, the vehicle 100 starts traveling on the "bad road" and the sound vibration start control is started.

Then, at time t2, when the required output P _r becomes equal to or greater than the rough road starting threshold P _{r_sbth} , the rough road starting flag f _bst is set and the engine 1 is started (Yes in step S450 and step S470). Along with this, power generation is started and the battery SOC begins to increase.

Next, at time t3, the rough road continuation rate R _bc exceeds the rough road continuation rate threshold R _{bc_th} , and the sound vibration start control becomes invalid (Yes in step S350 and step S360 in FIG. 6A). Then, the required output P _r becomes equal to or less than the rough road stop threshold P _{r_ebth} while driving on a rough road, the rough road stop flag f _ben is set, and the engine 1 is stopped (Yes in step S540, Yes in step S550, and ). Along with this, power generation stops and the battery SOC begins to decrease.

According to the control method according to the present embodiment described above, when the background noise of the vehicle 100 is in a high background noise state (when the road surface level Le is "3" or "4"), the background noise of the vehicle 100 is in a low background noise state (road surface level When the level Le is from "0" to "2"), control is realized that makes it easier to start the engine 1 and makes it more difficult to stop it. Therefore, when the vehicle 100 is running, the amount of generated power required according to the required output _Pr and the battery SOC can be satisfied while reducing the discomfort caused to the occupants due to the noise of the engine 1.

[Modified example]
Next, a modification of the control method described in the above embodiment will be described.

(Modification 1)
A configuration may be adopted in which execution and non-execution of the slip determination process, the estimated state determination process, or the sound vibration start determination process are switched by a predetermined switch (such as an ignition switch) operated by the occupant of the vehicle 100 or the like. For example, a configuration is adopted in which the appropriate estimation flag f _op is set to "0" in priority to the estimated state determination process, or a configuration in which the deactivation flag f _no is set to "1" in priority to the sound vibration start determination process. You may do so. Thereby, the occupant of the vehicle 100 or the like can select a mode in which the engine 1 is started or a mode in which the engine 1 is not started, as desired.

(Modification 2)
The on-vehicle actuator to which the control method of this embodiment is applied is not limited to the engine 1. In other words, if the device emits a certain level of operational sound (noise) that may cause discomfort to the occupants of the vehicle 100 when the road noise value is small, the control described in the above embodiment may be modified with some modifications. Can be applied. Examples of such in-vehicle actuators include air conditioners, fans, navigation systems, and audio. In addition, as another in-vehicle actuator, a running sound generator that generates a sound imitating the driving sound of the engine 1 in order to make those around the running vehicle 100 aware of the existence of the vehicle 100. The control method of this embodiment may be applied.

(Modification 3)
In this embodiment, the road surface level Le, which is an index of the level of background noise of the vehicle 100, is not limited to the five levels from "0" to "4". That is, it is an index of the magnitude of the background noise of the vehicle 100 based on the road noise value itself and the estimated state for the road noise value, and can be set at any stage if it is possible to distinguish between a high background noise state and a low background noise state. It is possible to set it to a number. Further, the index of the magnitude of the background noise of the vehicle 100 may be expressed as a continuous parameter.

(Modification 4)
Instead of the angular acceleration A of the wheels 7, or in addition to the angular acceleration A of the wheels 7, any other detected parameter correlated to the magnitude of the road noise may be employed as the detected parameter for calculating the road noise value. Such detection parameters include, for example, tire angular acceleration, running sound directly detected using a microphone, G sensor detection value (correlated with changes in acceleration due to road surface conditions), and suspension fluctuation amount. (variations due to road surface conditions), etc.

(Modification 5)
Depending on a predetermined operation mode set to vehicle 100, a configuration may be adopted in which execution or non-execution of slip determination processing, estimated state determination processing, sound vibration start determination processing, or engine starting itself is switched. For example, when the operation of the engine 1 is restricted by operating a predetermined switch (when the manner mode is set), or when the vehicle 100 is started (when the power is turned on) and the engine 1 is not started for the first time, The deactivation flag f _no may be set to "1" in priority to the sound vibration start determination process, or the operation of the engine 1 itself may be prohibited.

[Configuration of this embodiment and its effects 1]
According to the present embodiment, a vehicle-mounted actuator control method is provided that controls the operation of a vehicle-mounted actuator that is a source of noise. This in-vehicle actuator control method includes a road noise value estimation step (angular acceleration variance calculation unit 241 and variance correction 244), an estimated state determination step (FIG. 5) that determines whether the estimated state of the road noise value is an appropriate estimated state, and a dark state of the vehicle 100 based on the road noise value and the estimated state. Is it a high background noise state where the noise is relatively loud (road surface level Le = "3" to "4") or a low background noise state where the noise is relatively low (road surface level Le = "0" to "2")? a background noise state determination step (road surface level setting unit 245) for determining the background noise state of the vehicle 100; and an output adjustment step for adjusting the output of the on-vehicle actuator (engine 1) according to the determined background noise state of the vehicle 100 (FIGS. 7 and 8). ) and including.

Then, in the background noise state determination step (sound vibration start determination process), when it is determined that the estimated state is an appropriate estimated state (when all of the determination results in steps S200 to S240 in FIG. 5 are positive), It is determined whether the background noise of the vehicle 100 is in a high background noise state or a low background noise state according to the magnitude of the road noise value and a predetermined threshold value (road surface level Le = "2" and "3") ( Step S300 is Yes, and Steps S310 to S350). In the background noise state determination step, if it is determined that the estimated state is not a proper estimated state (No in step S300), it is determined that the background noise of the vehicle 100 is in a low background noise state regardless of the road noise value. (Step S360).

Furthermore, in the output adjustment step, when it is determined that the background noise of the vehicle 100 is in a high background noise state, the noise associated with the operation of the on-vehicle actuator (the noise associated with the operation of the engine 1) becomes relatively large. Set the output of the in-vehicle actuator to . On the other hand, when it is determined that the background noise of vehicle 100 is in a low background noise state, the output of the on-vehicle actuator is set so that the noise accompanying the operation of the on-vehicle actuator becomes relatively small.

As a result, the output of the on-vehicle actuator is increased in high background noise conditions in which it is difficult for the occupants of the vehicle 100 to recognize the noise accompanying the operation of the in-vehicle actuator, while the output of the in-vehicle actuator is decreased in low background noise conditions in which the noise is easily recognized. control is achieved. In particular, when the estimation accuracy of the road noise value (detection accuracy of angular acceleration A) is low, the background noise of the vehicle 100 is determined to be in a low background noise state regardless of the road noise value, thereby preventing erroneous determination. Based on this, it is possible to prevent a situation in which the output of the in-vehicle actuator is set high in a low background noise state. As a result, it is possible to more reliably prevent the noise caused by the operation of the vehicle-mounted actuator from causing discomfort to the occupants.

Note that in this embodiment, an on-vehicle actuator control device (controller 50) that executes the above-described on-vehicle actuator control method is provided. In particular, the controller 50 includes a road noise value estimation section (angular acceleration variance value calculation section, variance value correction section 244, and road surface level setting section 245) that executes the road noise value estimation process, and a road noise value estimation section that executes the above estimated state determination process. an estimated state determination section 243 that performs a background noise state determination step (road surface level setting section 245), and an output adjustment section (start/stop flag setting section 27 or target power generation operation) that performs an output adjustment step. It functions as a point setting section 28).

Further, in the estimated state determination step of the present embodiment, when the mechanical brake of the vehicle 100 is operating, it is determined that the estimated state of the road noise value is not a proper estimated state (No in step S200 and step S270).

That is, a specific scene in which it is determined that the road noise value estimation state is not a proper estimation state is a mechanical brake operation in which the frictional force acting on the wheel 7 becomes a disturbance element to the angular acceleration A for estimating the road noise value. You can set the time. In addition to the mechanical brake, the vehicle 100 of this embodiment is equipped with a regenerative brake that performs braking by adjusting the regenerative force of the drive motor 4 according to the amount of decrease in the accelerator opening APO. Therefore, depending on the braking scene, regenerative braking is expected to be performed more frequently than mechanical braking. For this reason, even if a control logic is adopted that determines that the operating state of the mechanical brake is not in the proper estimation state, it will always be determined that the braking scene of the vehicle 100 is not in the proper estimation state (the in-vehicle actuator is always activated during braking). The situation in which the output is set low is suppressed.

Furthermore, in the estimated state determination process of the present embodiment, if the wheels 7 are slipping, it is determined that the estimated state of the road noise value is not an appropriate estimated state (slip determination process in FIGS. 4A and 4B). That is, as a specific scene in which it is determined that the estimated state is not a proper estimated state, a slip time in which the vibration of the angular acceleration A due to the wheel 7 idling becomes a disturbance element can be set.

Further, in the estimated state determination step of the present embodiment, if the acceleration (longitudinal G estimated value) of the vehicle 100 is larger than a predetermined acceleration (longitudinal G detected value) determined from the viewpoint of determining sudden deceleration or sudden acceleration of the vehicle 100, Then, it is determined that the wheels 7 are slipping (Yes in step S150). In other words, a logic is realized in which a sudden deceleration or sudden acceleration in which a strong braking force or driving force is a disturbance factor compared to a normal deceleration or acceleration is determined to be a scene in which there is a risk of slipping.

Note that instead of or in addition to the acceleration of the vehicle 100, the target motor torque T _m of the drive motor 4, which is a traveling drive source mounted on the vehicle 100, is a predetermined value determined from the viewpoint of determining sudden deceleration or sudden acceleration of the vehicle 100. A configuration may be adopted in which it is determined that the wheels 7 are slipping when the driving force is greater than the driving force. In particular, in a scene where the vehicle 100 starts or stops on a slope, it is assumed that the deceleration or acceleration will be relatively small even during sudden deceleration or sudden acceleration. That is, depending on the driving scene, it is assumed that sudden deceleration or sudden acceleration cannot be identified with high precision from only deceleration or acceleration. On the other hand, since the target motor torque T _m is set including the gradient of the traveling road, increases and decreases resulting from sudden deceleration or sudden acceleration are suitably reflected even on a gradient road. Therefore, in a specific driving scene such as when driving on a slope, it is possible to more preferably identify the case where the vehicle 100 is slipping.

Furthermore, in this embodiment, the vehicle 100 is configured as a series hybrid vehicle that drives the generator 2 according to the required output P _r to charge the battery 3 and supplies power from the battery 3 to the drive motor 4 for driving. The on-vehicle actuator is configured as an engine 1 that drives a generator 2.

Then, in the output adjustment step, the required output P r for permitting the start of the engine 1 is determined according to the determined background noise state of the vehicle 100 (road surface level Le is one of "0" to "4") _. A starting threshold value P _{r_sth} is set (FIG. 7, FIG. 9). Further, a stop threshold P _{r_eth} , which is a threshold of the required output P _r for permitting the engine 1 to stop, is set (FIGS. 8 and 9).

In particular, when the required output P _r becomes equal to or greater than the starting threshold value P _{r_sth} , it is determined to start the engine 1, and when the required output P _r becomes equal to or less than the stop threshold value P _{r_eth} , it is determined to stop the engine 1.

Then, when it is determined that the background noise of the vehicle 100 is in a high background noise state (road surface level Le = "3" to "4"), the starting threshold P _{r_sth} is set to a relatively small first starting threshold (rough road start threshold P _{r_sbth} ) (Yes in step S430 and step S440). Further, the stop threshold P _{r_eth} is set to a relatively small first stop threshold (rough road stop threshold P _{r_ebth} ) (Yes in step S540 and step S550). On the other hand, when it is determined that the background noise of the vehicle 100 is in a low background noise state (road surface level Le = "0" to "2"), the starting threshold P _{r_sth} is set to a relatively large second starting threshold (normal starting threshold P _{r_suth} ) (No in step S430 and step S450). Further, the stop threshold P _{r_eth} is set to a relatively large second stop threshold (normal stop threshold P _{r_euth} ) (No in step S540 and step S560).

In this way, assuming the engine 1 in the series hybrid vehicle 100 as the in-vehicle actuator according to the control method described in the above embodiment, by changing the required output P _r for starting or stopping the engine 1 as the output adjustment, the vehicle The start timing and stop timing of the engine 1 can be adjusted so as not to cause discomfort to the occupants due to noise when the vehicle 100 is running.

[Configuration of this embodiment and its effects 2]
According to the present embodiment, an engine control method and an engine control device, which are one aspect of the above-mentioned in-vehicle actuator control method and in-vehicle actuator control device, are provided.

In the engine control method of this embodiment, a series hybrid type engine 1 drives a generator 2 to charge a battery 3 and supplies power from the battery 3 to a driving motor 4 according to a required output P _r . In the vehicle 100, a starting threshold P _{r_sth} is set as a threshold for the required output P _r for starting the engine 1. This engine control method is applicable to a high background noise state where the background noise of the vehicle 100 is relatively large (road surface level Le = "3" to "4") or a low background noise state where the background noise of the vehicle 100 is relatively small (road surface level Le = "3" to "4"). = “0” to “2”) (road surface level setting unit 245); and a start/stop threshold that sets the start threshold P _{r_sth} according to the background noise state of the vehicle 100. A setting step (start flag setting process).

In the start/stop threshold setting step, if it is determined that the background noise of the vehicle 100 is in a high background noise state, the start threshold P _{r_sth} is set to a relatively small first start threshold (rough road start threshold P _{r_sbth} ) (No in step S430 and step S450), and if it is determined that the background noise of the vehicle 100 is in a low background noise state, the starting threshold P _{r_sth} is set to a relatively large second starting threshold (normal starting threshold P _{r_suth} ) (Yes in step S430 and step S460).

Further, in the engine control method of the present embodiment, in the start/stop threshold setting step, the stop threshold P _{r_eth} , which is the threshold of the required output P _r for stopping the engine 1, is set depending on the background noise state of the vehicle 100. Set (stop flag setting process). Then, when it is determined that the background noise of the vehicle 100 is in a high background noise state (road surface level Le = "3" to "4"), the stop threshold P _{r_eth} is set to a relatively small first stop threshold (rough road stop threshold P _{r_ebth} ) (Yes in step S540 and step S550). Further, when it is determined that the background noise of the vehicle 100 is in a low background noise state (road surface level Le = "0" to "2"), the stop threshold P _{r_eth} is set to a relatively large second stop threshold (normal stop threshold P _{r_euth} ) (No in step S540 and step S560).

This makes it more difficult to stop the engine 1 in a high background noise state than in a low background noise state. As a result, as described above, the engine 1 is configured to be easy to start but difficult to stop in a high background noise state, which reduces the operating time of the engine 1 in a high background noise state where it is difficult for the occupants of the vehicle 100 to recognize the noise. By making the time longer, the amount of power generation (amount of charge to the battery 3) can be ensured more suitably. Furthermore, in a situation where a high background noise condition continues for a certain period of time, frequent repetition of starting and stopping of the engine 1 due to rough road starting threshold P _{r_sbth} and rough road stopping threshold P _{r_ebth} being close to each other is suppressed. Ru

Note that in this embodiment, an engine control method (controller 50) that executes the engine control method described above is provided. That is, the controller 50 includes a background noise state determination section (road surface level setting section 245) that executes a background noise state determination step, and a start/stop threshold setting section (start/stop flag setting section) that executes a start/stop threshold setting step. 27).

In particular, in the estimated state determination step of this embodiment, the rough road starting threshold P _{r_sbth} and the normal starting threshold P _{r_suth} are set to smaller values as the charging rate (battery SOC) of the battery 3 is lower. Thereby, the engine 1 can be started in both the high background noise state and the low background noise state so that the battery SOC does not fall below the appropriate range.

Furthermore, the engine control method of the present embodiment estimates a road noise value (road surface level Le in the range of "1" to "4") that quantifies the magnitude of road noise from the angular acceleration A of the wheels 7 of the vehicle 100. The process further includes a road noise value estimation step (angular acceleration variance calculation unit 241 and variance value correction unit 244). Then, the road surface level setting unit 245 determines that the background noise of the vehicle 100 is in a high background noise state when the road noise value is equal to or higher than a predetermined threshold value (road surface level Le = "2" and "3"). (Step S300 is Yes). Then, if the judgment of the high background noise condition based on the road noise value continues (if the bad road continuation rate R _bc is equal to or higher than the bad road continuation rate threshold R _{bc_th} over the specified driving distance _{D_th} ), the following In the control, it is determined that the background noise state of the vehicle 100 is a low background noise state regardless of the magnitude relationship between the road noise value and the threshold value (Yes in step S350 and step S360).

Thereby, it is possible to determine whether the background noise state of the vehicle 100 is a high background noise state or a low background noise state based on the magnitude relationship between the road noise value calculated from the angular acceleration A and the predetermined threshold value. That is, a specific control logic for determining the state of background noise of vehicle 100 is realized. In addition, if the state in which the road noise value is determined to be equal to or greater than the threshold value continues, the background noise state of the vehicle 100 will be determined to be a low background noise state in subsequent control. Therefore, overcharging of the battery 3 or reduction in fuel efficiency due to the engine 1 continuing to be started based on the rough road starting threshold P _{r_sbth} which is a value lower than the normal starting threshold P _{r_suth} can be more reliably prevented. Can be done.

In particular, the determination of the continuation of the high background noise state based on the road noise value is based on the ratio of the distance that the vehicle 100 travels on the rough road (the rough road continuation rate R _bc ) in a predetermined control period (the specified travel distance D _{_th} ). The judgment is made based on whether or not it is equal to or greater than the value (bad road continuation rate threshold R _{bc_th} ). As a result, it is possible to determine a suitable control period for determining a low background noise state regardless of the road noise value, assuming an actual driving scene of the vehicle 100. In addition, instead of the rough road continuation rate R _bc , the continuation of the state in which the road noise value is determined to be equal to or higher than the above threshold value is determined based on whether the proportion of the rough road driving time in a predetermined control period is equal to or higher than the reference value. A configuration may be adopted in which the judgment is made based on the following.

The engine control method of the present embodiment further includes an estimated state determining step (FIG. 5) of determining whether the estimated state of the road noise value is an appropriate estimated state. In the background noise state determination step, control timings in which the estimated state is determined not to be the appropriate estimated state are excluded from the control period (No in step S300).

As a result, when the estimation accuracy of the road noise value is not properly maintained depending on the driving scene of the vehicle 100, etc., a situation in which it is determined that the high background noise state described above is not continuing based on an erroneous determination ( As a result, a situation in which the background noise state is determined to be a low background noise state is suppressed. Thereby, it is possible to more reliably prevent the occupants of the vehicle 100 from feeling uncomfortable due to the operation of the engine 1 in a low background noise state.

In addition, in the engine control method of this embodiment, the starting threshold value P _{r_sth} and the stopping threshold value P _{r_eth} are basically set so that the amount of power generation that maintains the battery SOC within an appropriate range is achieved. In other words, since the required amount of power generation is determined by the amount of energy consumed when the vehicle 100 travels a certain distance (integral value of the required output P _r ), the operating time of the engine 1 is ensured according to the amount of power generation. There is a need to. In contrast, as mentioned above, by configuring the starting threshold P _{r_sth} and the stopping threshold P _{r_eth} in a high background noise state to be both smaller than those in a low background noise state, the necessary amount of power generation can be secured. The operating time of the engine 1 can be suitably maintained. In other words, the frequency in which vehicle 100 is running without operating engine 1 (EV running) can be maintained.

In particular, in this embodiment, the rough road stop threshold P _{r_ebth} and the normal stop threshold P _{r_euth} are set to larger values as the battery SOC is higher. Thereby, the engine 1 can be stopped so that the battery SOC does not exceed the appropriate range in both the high background noise state and the low background noise state.

Furthermore, the engine control method of the present embodiment includes an engine start determination step (FIG. 7) that generates a start command (start flag f _st ) for the engine 1 when the required output P _r becomes equal to _or higher than the start threshold P r_sth; The process includes an engine stop determination step (FIG. 8) that generates a stop command (stop flag f _en ) for the engine 1 when _r becomes equal to or less than the stop threshold P _{r_eth} .

In the engine start determination step, if the background noise of the vehicle 100 is in a high background noise state (No in step S430), a rough road start flag f _bst is generated when the required output P _r becomes equal to or higher than the rough road start threshold P _{r_sbth} . (Yes in step S450 and step S470), and when the background noise of the vehicle 100 is in a low background noise state (Yes in step S430), the normal start flag is set when the required output P _r becomes equal to or greater than the normal start threshold P _{r_suth} f _ust is generated (Yes in step S440 and step S460).

On the other hand, in the engine stop determination step (start/stop flag setting unit 27), if the background noise of the vehicle 100 is in a high background noise state (Yes in step S530), the required output P _r is set to the rough road stop threshold P _{r_ebth} If it is below, a rough road stop flag f _ben is generated (Yes in step S550 and step S570), and if the background noise of the vehicle 100 is in a low background noise state (No in step S530), the requested output P _r is When the normal stop threshold value P _{r_euth} or less is reached, a normal stop flag f _uen is generated (Yes in step S460 and step S580).

Thereby, a specific control logic for making it easier to start the engine 1 in a high background noise state than in a low background noise state and making it difficult to stop the engine 1 is realized.

Further, in the engine start command step, if the state in which the background noise of the vehicle 100 is determined to be a high background noise state continues (Yes in step S350 and step S360), the background noise of the vehicle 100 will be reduced in the subsequent control. Regardless of the state determination result, when the required output P _r becomes equal to or greater than the normal start threshold P _{r_suth} , a normal start flag f _ust is generated (Yes in step S430, Yes in step S440, and step S460).

As a result, even if the judgment that the high background noise state is present continues for a certain period of time or more, the engine 1 is not actually started based on the normal starting threshold value P _{r_suth} without being constrained by the judgment. Control logic is implemented that can initiate the . Therefore, overcharging of the battery 3 and deterioration of fuel efficiency described above can be avoided.

In addition, in the engine stop command process, if the background noise of the vehicle 100 continues to be determined to be a high background noise state, the request will be executed in the subsequent control regardless of the determination result of the background noise state of the vehicle 100. A configuration may be adopted in which a normal stop flag f _uen is generated when the output P _r becomes equal to or less than the normal stop threshold P _{r_euth} . With this configuration as well, overcharging of the battery 3 and deterioration of fuel efficiency can be avoided.

Further, in the engine stop command step in the engine control method of the present embodiment, when the requested output P _r becomes equal to or higher than the rough road starting threshold P _{r_sbth} and the engine 1 is started (Yes in step S530), the vehicle 100 is darkened. Regardless of the noise state, when the required output P _r becomes equal to or less than the rough road stop threshold P _{r_ebth} , a stop command (rough road stop flag f _ben ) is generated (Yes in step S550 and step S570). On the other hand, if the required output P _r is equal to or higher than the normal starting threshold P _{r_suth and} the engine 1 is started (No in step S530), the required output P _r is set to stop the vehicle 100 on rough roads depending on the background noise state of the vehicle 100. When the threshold P _{r_ebth} or the normal stop threshold P _{r_euth} is reached, a stop flag f _en is generated (steps S540 to S580).

As a result, if the engine 1 is started based on the rough road starting threshold P _{r_sbth} set in a high background noise state (especially when driving on a rough road), regardless of the background noise state at the time of stopping, the high background noise state The engine 1 will be stopped based on the rough road stop threshold P _{r_ebth} . Therefore, even though a relatively small rough road starting threshold P _{r_sbth} (for rough roads) is applied when engine 1 is started, a relatively large normal stop threshold P _{r_euth} (for good roads) is applied when engine 1 is stopped. By doing so, a situation in which the engine 1 is frequently started and stopped due to the start threshold P _{r_sth} and the stop threshold P _{r_eth} approaching each other is suppressed.

On the other hand, when the engine 1 is started based on the normal starting threshold P _{r_suth} set in a low background noise condition (especially when driving on a good road), the engine 1 is started based on the normal starting threshold P _{r_euth} that is set when stopped. Even if a small rough road starting threshold P _{r_sbth} is applied, the starting threshold P _{r_sth} and the stopping threshold P _{r_eth} are separated from each other by a certain degree. Therefore, the engine 1 can be stopped by applying the rough road stopping threshold P _{r_ebth} or less or the normal stopping threshold P _{r_euth} depending on the background noise state of the vehicle 100 when the vehicle 100 is stopped.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. do not have.

20 Vehicle speed calculation unit 22 Target driving force calculation unit 24 Road surface determination unit 26 Sound vibration start determination unit 27 Start/stop flag setting unit 28 Target power generation operating point setting unit 50 Controller 100 Vehicle 241 Angular velocity dispersion value calculation unit 242 Slip determination unit 243 Estimation Condition determination section 244 Dispersion value correction section 245 Road surface level setting section

Claims (8)

In a series hybrid vehicle in which an engine drives a generator to charge a battery and supply electric power to a drive motor for driving from the battery in accordance with the required output, a threshold value of the required output for starting the engine. An engine control method that sets a starting threshold that is and/or a stopping threshold that is a threshold of the required output for stopping the engine, the method comprising:
a background noise state determining step of determining whether the background noise of the vehicle is in a high background noise state where the background noise is relatively loud or in a low background noise state where the background noise is relatively low;
a start/stop threshold setting step of setting the start threshold and/or the stop threshold according to the state of background noise of the vehicle,
In the start/stop threshold setting step,
If it is determined that the background noise of the vehicle is in the high background noise state, setting the starting threshold to a relatively small first starting threshold;
If it is determined that the background noise of the vehicle is in the low background noise state, the starting threshold is set to a relatively large second starting threshold, and/or the background noise of the vehicle is in the high background noise state. If it is determined that the stop threshold is in the state, the stop threshold is set to a relatively small first stop threshold,
If it is determined that the background noise of the vehicle is in the low background noise state, setting the stop threshold to a relatively large second stop threshold ;
further comprising a road noise value estimation step of estimating a road noise value that quantifies the magnitude of road noise from the angular acceleration of the wheels of the vehicle,
In the background noise state determination step,
If the road noise value is greater than or equal to a predetermined threshold, determining that the background noise state of the vehicle is the high background noise state,
If the determination of the high background noise state based on the road noise value continues, the background noise state of the vehicle is determined to be the low background noise state in subsequent control regardless of the magnitude relationship between the road noise value and the threshold value. judge that there is
Engine control method. The engine control method according to claim 1,
The first start threshold and the second start threshold are set to smaller values as the charging rate of the battery decreases;
Engine control method. The engine control method according to claim 1 or 2 ,
further comprising an estimated state determining step of determining whether the estimated state of the road noise value is a proper estimated state,
In the background noise state determination step,
Excluding the control timing in which the estimated state is determined not to be the appropriate estimated state from the target of the determination of the high background noise state based on the road noise value;
Engine control method. The engine control method according to any one of claims 1 to 3 ,
The first stop threshold and the second stop threshold are set to larger values as the charging rate of the battery increases;
Engine control method. The engine control method according to any one of claims 1 to 4 ,
an engine start command step of generating a start command for the engine when the required output becomes equal to or higher than the start threshold;
further comprising an engine stop command step of generating a stop command for the engine when the required output becomes less than or equal to a stop threshold that is a threshold for the required output for stopping the engine;
In the engine start command step,
when the background noise of the vehicle is in the high background noise state, generating the start command when the required output becomes equal to or higher than the first start threshold;
When the background noise of the vehicle is in the low background noise state, generating the start command when the required output becomes equal to or higher than the second start threshold;
In the engine stop command step,
When the background noise of the vehicle is in the high background noise state, generating the stop command when the required output becomes less than or equal to the relatively small first stop threshold;
When the background noise of the vehicle is in the low background noise state, generating the stop command when the required output becomes equal to or less than the relatively large second stop threshold;
Engine control method. The engine control method according to claim 5 ,
In the engine start command step,
If the state in which the background noise of the vehicle is determined to be the high background noise state continues, the requested output is set to the second start regardless of the determination result of the background noise state of the vehicle in subsequent control. generating the start command when the threshold value is exceeded;
Engine control method. The engine control method according to claim 5 or 6 ,
In the engine stop command step,
When the engine is started when the required output is equal to or higher than the first start threshold, the stop command is generated when the required output becomes equal to or lower than the first stop threshold regardless of the state of background noise of the vehicle. death,
When the required output is equal to or greater than the second start threshold and the engine is started, the required output is equal to or less than the first stop threshold or equal to or less than the second stop threshold depending on the state of background noise of the vehicle. Then, the stop command is generated.
Engine control method. In a series hybrid vehicle in which an engine drives a generator to charge a battery and supply electric power to a drive motor for driving from the battery in accordance with the required output, a threshold value of the required output for starting the engine. An engine control device that sets a starting threshold that is and/or a stopping threshold that is a threshold of the required output for stopping the engine,
a background noise state determination unit that determines whether the background noise of the vehicle is in a high background noise state where the background noise is relatively loud or in a low background noise state where the background noise is relatively low;
a start/stop threshold setting unit that sets the start threshold and/or the stop threshold according to a background noise state of the vehicle;
The start/stop threshold setting section includes:
If it is determined that the background noise of the vehicle is in the high background noise state, setting the starting threshold to a relatively small first starting threshold;
If it is determined that the background noise of the vehicle is in the low background noise state, the starting threshold is set to a relatively large second starting threshold, and/or the background noise of the vehicle is in the high background noise state. If it is determined that the condition is the same, the stop threshold is set to a relatively small first stop threshold,
If it is determined that the background noise of the vehicle is in the low background noise state, setting the stop threshold to a relatively large second stop threshold ;
further comprising a road noise value estimation unit that estimates a road noise value that quantifies the magnitude of road noise from the angular acceleration of the wheels of the vehicle;
The background noise state determination unit includes:
If the road noise value is greater than or equal to a predetermined threshold, determining that the background noise state of the vehicle is the high background noise state,
If the determination of the high background noise state based on the road noise value continues, the background noise state of the vehicle is determined to be the low background noise state in subsequent control regardless of the magnitude relationship between the road noise value and the threshold value. judge that there is
Engine control device.

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