阅读说明：本技术 一种改善整车停车nvh性能的控制方法及装置 (Control method and device for improving NVH performance of parking of whole vehicle ) 是由 仇杰 薛小兵 李继 于 2018-05-29 设计创作，主要内容包括：本发明公开了一种改善整车停车NVH性能的控制方法及装置,所述控制方法包括：判断整车是否熄火停机；若整车是否熄火停机的判断结果为是,则根据发动机转速确定能够使进气门开启时刻在压缩上止点之后或者使排气门在压缩上止点以前关闭的VVT防振角度；将VVT系统的运行角度调节至确定的VVT防振角度,在整车熄火停机到发动机转速完全为0期间调整进气门或排气门的相位；将VVT系统的运行角度调回参考位置。该方法从振动源本身即三缸发动机方面提出了通过停机时更改VVT角度的策略,改善整车停机NVH性能,有效的解决停机时的整车抖动问题。(The invention discloses a control method and a control device for improving NVH (noise, vibration and harshness) performance of parking of a whole vehicle, wherein the control method comprises the following steps: judging whether the whole vehicle is flameout and stopped; if the judgment result of whether the whole vehicle stalls is yes, determining a VVT anti-vibration angle which can enable the opening time of the intake valve to be behind the compression top dead center or enable the exhaust valve to be closed before the compression top dead center according to the engine speed; adjusting the operation angle of the VVT system to a determined VVT anti-vibration angle, and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0; the operating angle of the VVT system is adjusted back to the reference position. The method provides a strategy for changing the VVT angle during shutdown from the aspect of a vibration source, namely a three-cylinder engine, improves the shutdown NVH performance of the whole vehicle, and effectively solves the problem of vehicle shaking during shutdown.)

1. a control method for improving NVH performance of parking of a whole vehicle comprises the following steps:

judging whether the whole vehicle is flameout and stopped;

if the judgment result of whether the whole vehicle stalls is yes, determining a VVT anti-vibration angle which can enable the opening time of the intake valve to be behind the compression top dead center or enable the exhaust valve to be closed before the compression top dead center according to the engine speed;

adjusting the operation angle of the VVT system to a determined VVT anti-vibration angle, and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

the operating angle of the VVT system is adjusted back to the reference position.

2. The control method for improving NVH performance of vehicle parking according to claim 1, comprising the following steps:

Setting a critical environment temperature for indicating that the external environment is in a low-temperature state;

Acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, increasing the rotating speed for adjusting the operating angle of the VVT system back to the reference position.

3. the control method for improving NVH performance of vehicle parking according to claim 1, comprising the following steps:

Setting a critical environment temperature for indicating that the external environment is in a low-temperature state;

Acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, not adjusting the operation angle of the VVT system.

4. the control method for improving NVH performance of vehicle parking according to claim 1, comprising the following steps:

And after the operation angle of the VVT system is adjusted back to the reference position, detecting whether the operation angle of the VVT system is at the reference position, if not, increasing the rotating speed threshold value for adjusting the operation angle of the VVT system back to the reference position when the VVT system is flamed out next time.

5. the control method for improving NVH performance of vehicle parking according to claim 1, comprising the following steps:

after the operation angle of the VVT system is adjusted back to the reference position, whether the operation angle of the VVT system is at the reference position or not is detected, and if the detection result is negative, the determined VVT anti-vibration angle is reduced to the VVT anti-vibration angle closer to the reference position when the flameout is carried out next time.

6. A control device for improving NVH performance of parking of a whole vehicle is characterized by comprising:

the judging unit is used for judging whether the whole vehicle is flameout and stops;

VVT vibration prevention angle determination means for determining a VVT vibration prevention angle capable of causing the intake valve opening timing to be after compression top dead center or causing the exhaust valve to be closed before compression top dead center, in accordance with the engine speed, when the determination result by the determination means is yes;

The VVT anti-vibration angle execution unit is used for adjusting the operation angle of the VVT system to the determined VVT anti-vibration angle and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

and the VVT angle callback unit is used for recalling the operation angle of the VVT system to the reference position.

7. the control device for improving NVH performance of the whole vehicle parking according to claim 6, characterized by comprising:

A temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

The temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

the comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

And the operation angle speed regulating unit is used for increasing the rotating speed for regulating the operation angle of the VVT system back to the reference position when the acquired real-time environment temperature is less than the set critical environment temperature.

8. the control device for improving NVH performance of the whole vehicle parking according to claim 6, characterized by comprising:

A temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

the temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

the comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

And the operation angle stopping and adjusting unit is used for controlling the VVT system not to adjust the operation angle when the acquired real-time environment temperature is less than the set critical environment temperature.

9. the control device for improving NVH performance of the whole vehicle parking according to claim 6, characterized by comprising:

an operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

And the operation angle speed regulating unit is used for increasing the rotating speed threshold value for regulating the operation angle of the VVT system back to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

10. The control device for improving NVH performance of the whole vehicle parking according to claim 6, characterized by comprising:

an operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

And the VVT anti-vibration angle adjusting unit is used for reducing the determined VVT anti-vibration angle to a VVT anti-vibration angle closer to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

Technical Field

the invention relates to the technical field of automobile engines, in particular to a control method for improving NVH (noise, vibration and harshness) performance of parking of a whole automobile. The invention also relates to a control device for improving the NVH performance of the whole vehicle parking.

Background

in recent years, a new generation of small-displacement three-cylinder supercharged engines are successively introduced by various large factories, the displacement is concentrated in a range of 1.0L-1.5L, and the power output level which can be achieved by a four-cylinder engine of the past grade of 1.6L-2.4L is originally obtained by smaller fuel consumption and more excellent exhaust emission performance.

However, three-cylinder engines have many disadvantages in terms of power consistency, vibration and noise, life and durability, high rotational speed power, throttle response, etc. compared to four-cylinder engines, even six-cylinder and eight-cylinder engines, three-cylinder engines have large vibration and noise, for example, which are determined by their physical properties because the engine cycle is divided into four parts: air inlet, compression, acting and exhaust, so when four jar engines just in time can guarantee two pistons upward movements, two other pistons downward movements offset vibrations each other, and three jar engines normal during operation have the piston of a jar with two other jar piston motion opposite direction anyway, can't accomplish the balance, so vibrations are great, otherwise six jar and eight jar engines are then more smooth-going.

the three-cylinder engine shakes greatly, so that the shaking of the whole vehicle is larger than that of a four-cylinder engine in the starting, stopping and normal running processes of the vehicle, particularly when the vehicle stops, the shaking of the whole vehicle, a seat and a steering wheel can be obviously felt due to the fact that the engine shakes greatly, and the customer experience is poor. In order to reduce the overall vehicle shake during shutdown, the following methods are generally adopted:

Firstly, the jitter is reduced through suspension debugging, but if suspension modification is carried out to avoid the problem of shutdown jitter, NVH (English abbreviation for noise, vibration and sound vibration roughness) performance of the vehicle under other working conditions is deteriorated, and a good balance cannot be achieved.

and secondly, when the vehicle is stopped, a throttle valve is closed, the resistance of a piston during operation is increased, the fluctuation of the rotating speed of the engine is reduced, and the shaking is reduced. But at present, on some three-cylinder whole vehicle projects, the throttle valve is closed to the minimum, but the whole vehicle shakes obviously.

thirdly, the vibration is reduced by increasing the inertia damping of the flywheel, and the vibration of the whole vehicle is mainly caused by the fluctuation of the rotating speed of an engine, so that the MT (manual transmission) and DCT (dual clutch transmission) vehicles are in a clutch disengagement state when the vehicles are stopped, and the effect of the method on reducing the vibration of the whole vehicle is not obvious.

Therefore, how to reduce the vibration when the three-cylinder engine is stopped is a technical problem to be solved by those skilled in the art.

disclosure of Invention

the invention aims to provide a control method for improving NVH (noise, vibration and harshness) performance of parking of a whole vehicle. The method provides a strategy for changing the angle of VVT (variable valve timing technology) during shutdown from the aspect of a vibration source, namely a three-cylinder engine, improves the shutdown NVH performance of the whole vehicle, and effectively solves the problem of shaking of the whole vehicle during shutdown.

The invention further aims to provide a control device for improving the NVH performance of the whole vehicle parking.

in order to achieve the first object, the invention provides a control method for improving the NVH performance of a vehicle parking, which comprises the following steps:

judging whether the whole vehicle is flameout and stopped;

if the judgment result of whether the whole vehicle stalls is yes, determining a VVT anti-vibration angle which can enable the opening time of the intake valve to be behind the compression top dead center or enable the exhaust valve to be closed before the compression top dead center according to the engine speed;

adjusting the operation angle of the VVT system to a determined VVT anti-vibration angle, and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

the operating angle of the VVT system is adjusted back to the reference position.

further, comprising:

setting a critical environment temperature for indicating that the external environment is in a low-temperature state;

Acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, increasing the rotating speed for adjusting the operating angle of the VVT system back to the reference position.

further, comprising:

setting a critical environment temperature for indicating that the external environment is in a low-temperature state;

acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, not adjusting the operation angle of the VVT system.

Further, comprising:

and after the operation angle of the VVT system is adjusted back to the reference position, detecting whether the operation angle of the VVT system is at the reference position, if not, increasing the rotating speed threshold value for adjusting the operation angle of the VVT system back to the reference position when the VVT system is flamed out next time.

Further, comprising:

after the operation angle of the VVT system is adjusted back to the reference position, whether the operation angle of the VVT system is at the reference position or not is detected, and if the detection result is negative, the determined VVT anti-vibration angle is reduced to the VVT anti-vibration angle closer to the reference position when the flameout is carried out next time.

to achieve the second object, the present invention provides a control device for improving NVH performance of a vehicle parking, including:

the judging unit is used for judging whether the whole vehicle is flameout and stops;

VVT vibration prevention angle determination means for determining a VVT vibration prevention angle capable of causing the intake valve opening timing to be after compression top dead center or causing the exhaust valve to be closed before compression top dead center, in accordance with the engine speed, when the determination result by the determination means is yes;

The VVT anti-vibration angle execution unit is used for adjusting the operation angle of the VVT system to the determined VVT anti-vibration angle and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

and the VVT angle callback unit is used for recalling the operation angle of the VVT system to the reference position.

preferably, the method comprises the following steps:

A temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

the temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

the comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

And the operation angle speed regulating unit is used for increasing the rotating speed for regulating the operation angle of the VVT system back to the reference position when the acquired real-time environment temperature is less than the set critical environment temperature.

preferably, the method comprises the following steps:

A temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

the temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

the comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

And the operation angle stopping and adjusting unit is used for controlling the VVT system not to adjust the operation angle when the acquired real-time environment temperature is less than the set critical environment temperature.

Preferably, the method comprises the following steps:

An operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

and the operation angle speed regulating unit is used for increasing the rotating speed threshold value for regulating the operation angle of the VVT system back to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

Preferably, the method comprises the following steps:

An operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

and the VVT anti-vibration angle adjusting unit is used for reducing the determined VVT anti-vibration angle to a VVT anti-vibration angle closer to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

In order to improve the NVH performance of the whole three-cylinder engine during parking, the invention develops a strategy for controlling the VVT during parking, the VVT is mainly controlled by the engine oil pressure, the engine oil pressure is gradually reduced along with the reduction of the rotating speed after the parking, the current strategy is to quickly return to the reference position after shutdown, no longer make VVT adjustments, ensure that the VVT returns to the reference position after shutdown, on the basis, the VVT control strategy is added during the shutdown, when the whole vehicle is shut down until the rotating speed is completely 0, the phase of an intake valve or an exhaust valve is adjusted, the opening moment of the intake valve is enabled to be behind the compression top dead center or the exhaust valve is enabled to be closed before the compression top dead center, the running resistance of the engine piston is increased, namely, an air spring is added in the engine, so that the vibration of the engine during the shutdown is effectively reduced, and the shutdown NVH performance of the whole vehicle is improved.

The control device for improving the NVH performance of the whole vehicle parking can realize the control method, and the control device for improving the NVH performance of the whole vehicle parking also has corresponding technical effects because the control method for improving the NVH performance of the whole vehicle parking has the technical effects.

drawings

FIG. 1 is a control flow chart of a control method for improving NVH performance of parking of a whole vehicle according to the present invention.

Detailed Description

in order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

a typical VVT system consists essentially of a phaser, which is the actuator of the system, and an oil control valve, which is the controller of the system.

An engine management system EMS (generally called as an engine ECU) searches a MAP (MAP) according to signals transmitted by a throttle opening sensor, an engine water temperature sensor, a rotating speed sensor, an air flow meter and the like, and calculates a required valve timing angle, namely a target position, of the engine under each working condition; meanwhile, an engine management system EMS calculates the actual position of the camshaft according to feedback signals transmitted by a crankshaft position sensor and a cam position sensor. EMS compares the target position with the actual position, sends an actuating signal to the engine oil control valve according to the control strategy of EMS, changes the position of a valve core in the control valve, thereby changing the flow direction and the flow rate of the engine oil in an oil way, and feeds signals of advance, lag, constant maintenance and the like back to the cavity of the VVT phaser in an oil pressure mode, so as to realize the relative rotation between the inner stator and the outer rotor of the phaser, adjust the timing angle of the camshaft, and further achieve the purposes of adjusting the air intake (exhaust) amount and the opening and closing time of the valve.

Referring to fig. 1, fig. 1 is a control flow chart of a control method for improving NVH performance of a vehicle parking according to the present invention.

in a specific embodiment, the control method for improving the NVH performance of the vehicle parking provided by the invention comprises the following steps:

firstly, judging whether the whole vehicle is flameout and stopped;

And then, if the judgment result of whether the whole vehicle is flamed out and stopped is yes, determining the VVT anti-vibration angle according to the engine speed, namely increasing the VVT angle running along with the engine speed.

The principle of setting the VVT vibration-proof angle is as follows: the intake valve opening timing is made to be after compression top dead center or the exhaust valve is made to be closed before compression top dead center.

specifically, a calibrated MAP for operating the VVT system may be added according to the engine speed and the engine oil temperature, and data setting may be performed according to the actual vehicle shaking condition, for example, data setting of a VVT anti-vibration angle may be performed when the engine oil temperature is high and the rotation speed interval is above 500 revolutions, and during operation, the engine controller gives an instruction to the VVT actuator to operate the VVT actuator according to the set angle.

Then, adjusting the operation angle of the VVT system to a determined VVT anti-vibration angle, and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

finally, the operating angle of the VVT system is adjusted back to the reference position.

Because the engine oil temperature is lower at low temperature, the VVT regulating speed can be slowed down, so that the rotating speed of the VVT returning to the reference position can be improved at low temperature, the VVT can not return to the reference position, namely, the MAP correction by increasing the ambient temperature is prevented. The specific implementation mode is as follows:

setting a critical environment temperature for indicating that the external environment is in a low-temperature state;

acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, increasing the rotating speed for adjusting the operating angle of the VVT system back to the reference position.

the set critical environment temperature may be any temperature value between 10 ℃ and 20 ℃, or any temperature value between 15 ℃ and 20 ℃, or any temperature value between 10 ℃ and 18 ℃ and between 15 ℃ and 22 ℃, and within a temperature range lower than the set critical environment temperature, the temperature ranges may be further divided into different temperature ranges, the temperature ranges are sorted according to the gradient of the temperature ranges, the rotation speed is gradually increased, each temperature range corresponds to an increased rotation speed range, taking the critical environment temperature as 20 ℃, when the external environment temperature is below 20 ℃, the rotation speed starts to be increased, and the specific calibration is as follows:

Critical ambient temperature	Rotational speed
		20 ℃ and above	640 turns
0℃-20℃	640 to 720 revolutions
		-20℃～0℃	720 to 800 turns
-20 ℃ and below	800 turn

In addition, the suspension of the whole vehicle at low temperature is harder, and the NVH of the whole vehicle at low temperature is better than that at normal temperature through test verification, so that the whole vehicle can not be shaken under the condition of not using VVT control after shutdown at low temperature. The specific implementation mode is as follows:

setting a critical environment temperature for indicating that the external environment is in a low temperature state (the specific setting manner may be the same as above);

acquiring the real-time environment temperature of the external environment;

And comparing the acquired real-time environment temperature with the set critical environment temperature, and if the acquired real-time environment temperature is less than the set critical environment temperature, not adjusting the operation angle of the VVT system.

The two correction schemes aiming at low temperature can be selected for use, namely, when the external environment is detected to be in a low-temperature state, the rotating speed of the VVT system for adjusting the running angle back to the reference position can be selected to be increased, so that the running angle of the VVT system can be accurately adjusted back to the reference position, and the running angle of the VVT system can be selected not to be adjusted, so that the running angle of the VVT system can quickly return to the reference position.

On the basis, another modification scheme can be designed, namely two critical environment temperatures are preset and are respectively a first critical environment temperature and a second critical environment temperature, wherein the first critical environment temperature is higher than the second critical environment temperature, and when the real-time environment temperature is lower than the first critical environment temperature and higher than the second critical environment temperature, the rotating speed of the VVT system is selected to be increased to adjust the operating angle of the VVT system back to the reference position, so that the operating angle of the VVT system can be accurately adjusted back to the reference position; and when the real-time environment temperature is lower than the second critical environment temperature, selecting not to adjust the operation angle of the VVT system, so that the operation angle of the VVT system quickly returns to the reference position.

If the running angle of the VVT system can not return to the reference position after the shutdown, the VVT system has the risk of jumping randomly in the next starting process of the vehicle, can not run according to the normal target position, easily causes the starting performance to be poor, and can possibly damage a phase modulator in serious conditions. In contrast, a monitoring function of whether the VVT can return to the reference position after the shutdown can be added, and the VVT is prevented from failing to return to the reference position.

specifically, after the operating angle of the VVT system is adjusted back to the reference position, whether the operating angle of the VVT system is at the reference position is detected, and if the detection result is negative, the rotation speed threshold for adjusting the operating angle of the VVT system back to the reference position is increased when the engine is turned off next time.

or after the operation angle of the VVT system is adjusted back to the reference position, whether the operation angle of the VVT system is at the reference position is detected, if the detection result is negative, the determined VVT anti-vibration angle is reduced when the VVT system is switched off next time, the reduction amplitude is preferably closer to the reference position, namely, the operation angle of the VVT system can be accurately returned to the reference position by changing the VVT angle controlled by the target and reducing the adjustment angle.

The above two control strategies for preventing the VVT from returning to the reference position may be used alternatively or together.

the above embodiments are merely preferred embodiments of the present invention, and are not limited thereto, and on the basis of the above embodiments, various embodiments can be obtained by performing targeted adjustment according to actual needs. For example, other parameters are introduced to correct the set VVT anti-vibration angle, or other strategies are adopted to ensure that the operation angle of the VVT system can accurately return to the reference position, and so on. This is not illustrated here, since many implementations are possible.

besides the control method, the invention also provides a control device for improving the NVH performance of the whole vehicle parking, which comprises the following steps:

the judging unit is used for judging whether the whole vehicle is flameout and stops;

VVT vibration prevention angle determination means for determining a VVT vibration prevention angle capable of causing the intake valve opening timing to be after compression top dead center or causing the exhaust valve to be closed before compression top dead center, in accordance with the engine speed, when the determination result by the determination means is yes;

The VVT anti-vibration angle execution unit is used for adjusting the operation angle of the VVT system to the determined VVT anti-vibration angle and adjusting the phase of an intake valve or an exhaust valve when the whole vehicle is shut down and the engine speed is completely 0;

And the VVT angle callback unit is used for recalling the operation angle of the VVT system to the reference position.

because the engine oil temperature is lower at low temperature, the VVT regulating speed can be slowed down, so that the rotating speed of the VVT returning to the reference position can be improved at low temperature, the VVT can not return to the reference position, namely, the MAP correction by increasing the ambient temperature is prevented. Therefore, the control device further includes:

a temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

The temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

the comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

and the operation angle speed regulating unit is used for increasing the rotating speed for regulating the operation angle of the VVT system back to the reference position when the acquired real-time environment temperature is less than the set critical environment temperature.

In addition, the suspension of the whole vehicle at low temperature is harder, and the NVH of the whole vehicle at low temperature is better than that at normal temperature through test verification, so that the whole vehicle can not be shaken under the condition of not using VVT control after shutdown at low temperature. If such a control strategy is adopted, the control device further includes:

A temperature setting unit for setting a critical environment temperature indicating that an external environment is in a low temperature state;

The temperature detection unit is used for acquiring the real-time environment temperature of the external environment;

The comparison unit is used for comparing the acquired real-time environment temperature with the set critical environment temperature;

And the operation angle stopping and adjusting unit is used for controlling the VVT system not to adjust the operation angle when the acquired real-time environment temperature is less than the set critical environment temperature.

as described above, the function of monitoring whether the VVT can return to the reference position after the shutdown can be added, and the VVT is prevented from failing to return to the reference position. Therefore, the control device may further include:

an operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

And the operation angle speed regulating unit is used for increasing the rotating speed threshold value for regulating the operation angle of the VVT system back to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

Alternatively, it comprises:

An operation angle detection unit for detecting whether an operation angle of the VVT system is at a reference position after adjusting the operation angle of the VVT system back to the reference position;

And the VVT anti-vibration angle adjusting unit is used for reducing the determined VVT anti-vibration angle to a VVT anti-vibration angle closer to the reference position when the next flameout occurs if the detection result of the operation angle detecting unit is negative.

the VVT control strategy is added during the shutdown, when the whole vehicle is flamed out and is shut down until the rotating speed is completely 0, the phase of the intake valve or the exhaust valve is adjusted, the opening moment of the intake valve is enabled to be behind the compression top dead center or the exhaust valve is enabled to be closed before the compression top dead center, the running resistance of an engine piston is increased, namely, an air spring is added in the engine, so that the jitter of the engine during the shutdown is effectively reduced, and the NVH performance of the shutdown of the whole vehicle is improved.

The control method and the control device for improving the NVH performance of the parking of the whole vehicle provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the core concepts of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.