JP7502133B2 - vehicle - Google Patents

Description

The present invention relates to a technology capable of controlling the airflow around a vehicle, and more specifically, to a vehicle capable of reducing wind throb noise in the vehicle by controlling the airflow using a plasma actuator.

Conventionally, techniques have been proposed for reducing wind throbbing noise in vehicles, such as by arranging a wind deflector on a door frame.
For example, Patent Document 1 discloses a technique for reducing wind throbbing (resonating noise within the vehicle cabin) by providing a wind deflector on a door frame to redirect the flow of outside air away from the door opening.

Patent Document 2 discloses that when the vehicle's side window is opened and the vehicle speed is equal to or greater than a predetermined value, the door frame garnish is raised to reduce wind throttling. Patent Document 3 discloses technology for a racing car equipped with a front wing and a rear wing that can arbitrarily select the effect of generating downforce and reducing air resistance depending on the driving conditions, such as lateral G, cornering, straight running, and speed, to obtain the most suitable aerodynamic effect for each vehicle speed and driving condition.

Furthermore, according to Patent Document 4 and Patent Document 5, it is possible to rectify the airflow around the vehicle using plasma generated by a PA (plasma actuator). More specifically, for example, Patent Document 4 proposes installing a PA on the A-pillar or fender of the vehicle, and suppressing (rectifying) the separation flow of air flowing around the vehicle by driving the PA.

Patent Document 5 also discloses that a PA is placed upstream of an aircraft's weapons bay, and the shear layer of the airflow is deflected away from the weapons bay, thereby reducing the sound level generated while the weapons bay door is open.

JP 2000-301943 A JP 2008-195107 A JP 2010-158977 A U.S. Pat. No. 9,821,862 JP 2008-290711 A

Existing technologies, including those described in the above patent documents, do not adequately meet the market needs for reducing wind throb noise, and the following problems exist. That is, if a plasma actuator such as that shown in patent documents 4 and 5 is installed in the position of a wind deflector such as that shown in patent documents 1 to 3, it is certainly possible to reduce wind throb noise by controlling the periodic vortexes around the vehicle that cause wind throb noise.

However, existing technologies, including those described in the above patent documents, and combinations of these technologies, do not allow for control of the PA in accordance with the specific conditions of a vehicle while it is moving. In other words, if it were possible to control the PA in accordance with the specific conditions of a vehicle, that is, the opening and closing status of the windows, and a combination of factors such as the vehicle speed, steering angle, and lateral acceleration, it would be possible to achieve a more comfortable driving experience by further reducing wind throb noise.

The present invention has been made in consideration of the above-mentioned problems, and aims to provide a vehicle that can improve driving comfort by using a plasma actuator to control the wind throb noise generated in the vehicle depending on the vehicle conditions such as the opening and closing status of the windows, the vehicle speed, the steering angle, and the lateral acceleration.

To solve the above problem, one embodiment of the present invention provides a vehicle comprising: (1) a plasma actuator provided in a portion of the vehicle body; a vehicle condition detection unit that detects vehicle condition values of the vehicle body; and a control device that controls the plasma actuator in response to the vehicle condition values obtained by the vehicle condition detection unit to reduce wind throb noise in the vehicle.

In the above (1), (2) the vehicle condition value is at least one of the window opening degree and the driving condition of the vehicle, and the driving condition can be at least one of the vehicle speed, steering angle, and lateral acceleration.

In addition, in the above (1) or (2), (3) a sound collection sensor that detects wind throb noise in the vehicle is further provided, and the control device can control the output value of the plasma actuator based on the value detected by the sound collection sensor.

In any of the above (1) to (3), (4) the plasma actuator may be disposed at an open end of a window of the vehicle, and the window of the vehicle may be a side window or a sunroof.

In any of the above (1) to (4), (5) a vehicle environment detection unit may be further provided for detecting a vehicle environment value in the vehicle, and the control device may control the output value of the plasma actuator based on the vehicle environment value detected by the vehicle environment detection unit.

The present invention makes it possible to provide a vehicle that can improve driving comfort by reducing wind throb noise that occurs in the vehicle depending on the vehicle conditions.

1 is a side view of a vehicle with a wind throb noise reduction function according to an embodiment of the present invention; 1 is a plan view of a vehicle with a wind throb noise reduction function according to an embodiment, as viewed from above; FIG. 2 is a functional block diagram of a vehicle equipped with a wind throb noise reduction function. 4 is a flowchart showing a method for controlling wind throb noise using a plasma actuator according to an embodiment. 11 is a graph showing a change in noise level inside a cavity due to a plasma actuator according to an embodiment.

Next, a preferred embodiment for carrying out the present invention will be described. Note that, for example, for parts of the driving mechanism of the plasma actuator other than those described in this embodiment, known plasma actuator mechanisms, including those described in the patent documents listed above, may be used. In addition, for vehicle configurations other than those described in detail in this embodiment, known component technologies and mechanisms related to vehicles may be used to supplement the configuration.

[Vehicle 100]
First, a vehicle 100 according to this embodiment will be described with reference to Figures 1 to 3. As shown in the figures, the vehicle 100 according to this embodiment is preferably a four-wheeled vehicle, but may be applied to other known vehicles, such as two-wheeled vehicles, as long as they generate the wind throb noise described above. As a four-wheeled vehicle, in addition to gasoline-powered vehicles, hybrid vehicles and electric vehicles equipped with various types of secondary batteries may be used.

The vehicle 100 of this embodiment has a wind throbbing noise reduction function that reduces low-frequency (10 to 50 Hz) noise called wind throbbing noise that occurs when the vehicle is driven with the windows open, and is configured to include at least a plasma actuator 10, sensors 20, and a control device 30.
In the present invention, the above-mentioned wind throbbing noise refers to a coupled phenomenon between the release of periodic vortices (periodic vortices) generated at window openings, which is generally known as part of aerodynamic noise, and Helmholtz resonance in the vehicle cabin space.

<Plasma actuator 10>
The plasma actuator 10 of this embodiment has a function of reducing wind throbbing noise in a vehicle. More specifically, the plasma actuator 10 of this embodiment has a function of collapsing or separating periodic vortices that are generated at the front end F1 of the opening WO of the window W while the vehicle is traveling. Examples of the opening WO in which such periodic vortices are generated in the vehicle 100 include the side window of the vehicle shown in Figure 1, as well as a sunroof as shown in Figure 2 and a rear window (not shown).

The specific structure of the plasma actuator 10 is a known plasma actuator disclosed in, for example, Patent Document 4 or Patent Document 5, and in this embodiment, a dielectric barrier discharge (DBD) type plasma actuator can be applied. Note that the plasma actuator 10 of this embodiment is not limited to the DBD plasma actuator described above, and other known PAs may be applied, such as a sliding discharge (SD) type plasma actuator that has been improved to have a larger plasma generation area.

Specifically, the plasma actuator 10 of this embodiment is configured to include at least two plasma actuators PA1 and PA2 each provided at the front end of a side window at the rear (rear seat) of the vehicle 100 in the traveling direction.
In addition, as can be understood from Figures 1 and 2, the vehicle 100 of this embodiment may be configured to include plasma actuators PA3 and PA4 respectively provided at the front ends of the side windows forward in the direction of travel of the vehicle 100 (driver's seat or passenger seat), or a plasma actuator PA5 located at the front end of the sunroof.

More specifically, the plasma actuators PA1 and P2 of this embodiment are disposed at the front ends of both side windows on the rear side of the vehicle 100, i.e., above the center pillar, and extend in the vehicle height direction (Z direction in FIG. 1). Note that the plasma actuators PA1 and PA2 of this embodiment may be disposed over the entire front ends of the above-mentioned side windows, or may be disposed intermittently.

The plasma actuators PA3 and PA4 of this embodiment are disposed at the front ends of both side windows on the front side of the vehicle 100, i.e., above the A-pillars, and extend in the vehicle height direction (Z direction in FIG. 1). Note that the plasma actuators PA3 and PA4 of this embodiment may be disposed over the entire front ends of the above-mentioned side windows, or may be disposed intermittently.

The plasma actuator PA5 of this embodiment is disposed at the front end of the sunroof of the vehicle 100 (e.g., near the line connecting the upper ends of the left and right A-pillars) and extends in the vehicle width direction (X direction in FIG. 1). Note that the plasma actuator PA5 of this embodiment may be disposed over the entire width of the front end of the sunroof described above, or may be disposed intermittently.

The above-mentioned installation of the plasma actuators PA1 to PA5 is just one example, and they may be installed in other locations on the vehicle 100 as long as they are able to separate or collapse the periodic vortexes described above.

<Sensors 20>
As shown in Fig. 3, the sensors 20 of this embodiment include sensors that detect vehicle status values. The vehicle status values are values that indicate the state of the vehicle while it is traveling, and examples of such values include the window opening degree, vehicle speed, steering angle, and lateral acceleration. As examples of sensors that detect the above-mentioned vehicle status values, the sensor 20 includes a window opening degree sensor 201, a vehicle speed sensor 202, a steering angle sensor 203, and a lateral acceleration sensor 204.

The window opening sensor 201 can be, for example, a known sensor capable of measuring the opening degree of a window at a specific location on the vehicle 100 while it is moving. This enables the control device 30 to control the operation of the plasma actuator 10 according to the window opening degree obtained from the window opening sensor 201.

The vehicle speed sensor 202 can be, for example, a known sensor capable of measuring the speed of the vehicle 100 while it is moving. This allows the control device 30 to control the operation of the plasma actuator 10 according to the vehicle speed obtained from the vehicle speed sensor 202.

The steering angle sensor 203 may be a known sensor capable of detecting the steering angle while the vehicle 100 is traveling. Specifically, the steering angle sensor is installed at any location near the steering shaft of the steering device, and has the function of detecting the steering angle of the steering wheel by outputting a signal corresponding to the rotation angle of the steering shaft at the installation position.

The lateral acceleration sensor 204 can be, for example, a known sensor capable of measuring the speed of the vehicle 100 while it is moving. This allows the control device 30 to control the operation of the plasma actuator 10 according to the vehicle speed obtained from the lateral acceleration sensor 204.

In addition to the sensors that detect the vehicle status values, a sound collection sensor 205 may be provided at any location in the vehicle 100 .
The sound collection sensor 205 may be a known microphone capable of detecting aerodynamic noise (wind throb noise) inside the vehicle cabin while the vehicle is moving. The frequency of the sound to be collected is preferably the low frequency band (10 to 50 Hz) that is the target of this embodiment. Note that the sound collection performance can be further improved by applying a sound absorbing agent to the vehicle cabin to reduce sounds other than the low frequency band (10 to 50 Hz).
The location where the sound sensor 205 is installed may be, for example, near the rear end F2 of the opening WO of the window W where wind throb noise is thought to be loudest inside the vehicle cabin, but is not limited to this.

Furthermore, the sensors 20 of the embodiment may be configured to include a sensor that detects vehicle environmental values. The vehicle environmental values are values that represent the influences that the vehicle receives from the outside (environment outside the vehicle cabin) while traveling, and examples of sensors that detect vehicle environmental values include a wind speed sensor 206 and a road direction sensor 207.

The wind speed sensor 206 serves to detect the wind speed around the vehicle when it is stopped. This wind speed sensor 206 can be installed at any position outside the vehicle body. Also, instead of installing a wind speed sensor 206 that directly measures the wind speed around the vehicle when it is stopped, an external wind speed measuring device that can obtain wind speed information within the vehicle via a known external communication device CS may function as the wind speed sensor 206.

The road direction sensor 207 may be a known camera or the like capable of detecting the vehicle's traveling direction, and may be installed anywhere on the vehicle. Also, instead of detecting the vehicle's traveling direction with a camera, it is also possible to obtain information on the road direction from road information or the like in a navigation device NS mounted on the vehicle.

<Control device 30>
The control device 30 has a function of controlling the plasma actuator 10 described above to reduce wind throbbing noise in the passenger compartment of the vehicle 100 while the vehicle 100 is running.
A specific example of the control device 30 is a known integrated circuit (control IC) that is powered by a battery (not shown), such as a known lithium ion secondary battery or a nickel metal hydride battery, mounted on the vehicle 100. The control device 30 of this embodiment may also include a memory (not shown) that stores an executable control program, such as a rectification method described below.

Such a control device 30 has the function of generating high-frequency signals that drive each of the above-mentioned plasma actuators 10 (plasma actuators PA1 to PA5). As a more specific example, the control device 30 of this embodiment is configured to include a known inverter element that converts the DC voltage of the battery described above into AC voltage.

The battery described above has the function of supplying the necessary power to the plasma actuator 10 and the sensors 20. The battery in this embodiment may be any other known battery, such as a lead acid battery or a nickel-metal hydride battery, as long as it is capable of boosting the voltage to the driving voltage of the plasma actuator.

The control device 30 of this embodiment preferably includes a boost circuit that boosts the voltage from the battery to a voltage at which the plasma actuator can be driven. More specifically, the boost circuit of this embodiment can be, for example, a known transformer that can boost the voltage of the installed car battery (12V or 24V) or the voltage of the motor battery (several hundredV) to several thousandV. Note that the plasma actuator 10 of this embodiment is a known plasma actuator that can be driven at several thousandV, but the boost ratio by the boost circuit 50 can be changed as appropriate depending on the value of the drive voltage of the plasma actuator.

More specifically, as shown in FIG. 3, the control device 30 of this embodiment includes a vehicle condition detection unit 31, a vehicle environment detection unit 32, a determination unit 33, a PA drive control unit 34, and a presentation unit 35.
Of these, the vehicle condition detection unit 31 has a function of receiving information on the vehicle condition from the sensors 20 that detect the above-mentioned vehicle condition values.
The vehicle environment detection unit 32 also has a function of receiving information about the vehicle environment from the sensors 20 that detect the above-mentioned vehicle environment values.

As described below, the judgment unit 33 has the function of determining whether or not it is necessary to drive the plasma actuator in response to the wind throb noise to be controlled, depending on conditions such as vehicle status values or a combination of vehicle status values and vehicle environmental values.
The PA drive control unit 34 has a function of controlling the drive of the plasma actuators 10 (PA1 to PA5) via the above-mentioned boost circuit, etc. Note that the drive control of the plasma actuator 10 may be performed using a known control mechanism for a plasma actuator in addition to the present embodiment.
The presentation unit 35 presents setting screens for various equipment installed in the vehicle 100 via the presentation device DS described later, and also has the function of presenting the driving status and behavior control status of the above-mentioned plasma actuator 10 to the occupants.

The external communication device CS can be, for example, a known communication device that can communicate various types of information with the outside world using packet communication using the above-mentioned smartphone or next-generation automotive wireless communication technology, such as connected services.

The storage device MR can be, for example, a known recording device/storage device such as a hard disk drive or non-volatile memory, and is a means capable of recording various information such as the conditions under which wind throb noise occurred in the past.
The navigation device NS can be, for example, a known navigation system equipped with a GPS function, and is capable of detecting position information of the vehicle 100 in cooperation with the above-mentioned control device 30. Furthermore, the navigation device NS stores map information (not shown), and the control device 30 can detect the absolute position of the vehicle by referring to the map information.

In this embodiment, the presentation device DS is configured to include a known speaker SP and display DP mounted on the vehicle. Of these, the display DP may also be used as a monitor for the navigation device NS. In addition, the presentation device DS of this embodiment may be configured to be capable of short-range wireless communication with a portable device such as a smartphone owned by the occupant.

[Method of controlling vehicle behavior using plasma actuators]
Next, with further reference to FIGS. 4 and 5, a method for controlling wind throb noise using a plasma actuator, which is executed by the control device 30 in this embodiment, will be described.

4, in step 1-A, a vehicle status value of the vehicle 100 is detected. Specifically, the window opening sensor 201 detects the opening degree of the window.
Next, in step 2, the control device 30 determines whether the current window opening degree detected in step 1 is equal to or greater than a predetermined value. As a result, for example, when the window opening degree is small, wind throbbing noise is relatively unlikely to occur, or even if it does occur, the noise is small, so that the drive of the plasma actuator 10 can be stopped, thereby achieving the above-mentioned energy saving of the battery.

The "predetermined value" of the window opening in step 2 described above can be set to various values depending on the type of vehicle 100 and the region in which the vehicle is driven. As an example, in this embodiment, a window opening of 25% is set as the predetermined value, and in this case, if the rear seat side window is opened less than 25% (1/4), the operation of the plasma actuator 10 is stopped. Note that a window opening of 25% refers to the height of the opening when the height of the window in the Z direction of the vehicle 100 is set to 100.

The control device 30 may also refer to map information from the navigation device NS and vary the "predetermined value" according to the current location of the vehicle 100. This allows the "predetermined value" to be set according to the location, for example, when traveling in an area where strong winds are likely to occur, such as a valley or basin, or in a place where reverberation is expected, such as inside a tunnel, thereby further improving driving comfort.

Between step 1-A and step 2, step 1-B may be provided for detecting the vehicle environment values. Step 1-B is not essential and may be omitted as appropriate. Details regarding step 1-B will be described later. If step 1-B for detecting the vehicle environment values is provided, it is possible to control the drive of the plasma actuator 10 according to the combination pattern of the vehicle status values detected in the above-mentioned step 1-A and the vehicle environment values detected in step 1-B.

If the current vehicle status value is "PA operation required" (Yes in step 2) in step 2, the control device 30 refers to the wind throb noise control table stored in the memory or storage device MR and controls the output of the plasma actuator at a specified position in the following step 3. At this time, as shown in FIG. 1, etc., the plasma actuator is positioned so that the periodic vortex generated at the front end F1 of the window opening WO in the moving vehicle 100 collapses or is separated from the rear end F2 of the window opening WO.

As an example, the reduction of wind throbbing noise at rear passenger windows will be described.
More specifically, controller 30 controls the output of plasma actuator PA1 in accordance with the value of the window opening degree detected in step 1-A.

For example, if the output of plasma actuator PA1 is controlled in two stages, the output of plasma actuator PA1 can be set to "weak" if the window opening degree detected in step 1-A is between 25% and 50%, and the output of plasma actuator PA1 can be set to "strong" if the window opening degree detected in step 1-A is between 50% and 100%, thereby making it possible to appropriately control the wind throbbing noise of vehicle 100.

Figure 5 is a schematic diagram showing the difference in noise levels when the plasma actuator 10 of this embodiment is driven and when it is not driven in a cavity with an opening simulating a vehicle interior. As shown in Figure 5, when the plasma actuator 10 is not driven (PA-OFF), a characteristic noise level peak is observed in a frequency band at a specific period, whereas when the plasma actuator 10 is driven (PA-ON), the peak disappears.

The above describes in detail preferred embodiments of the present invention with reference to the attached drawings, but the present invention is not limited to these examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains may attempt further modifications to these embodiments and variations within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, the vehicle status value focuses on only a single element, the window opening degree, but this is not limited to this. Two elements, "window opening degree" and "vehicle speed", may be detected, and the plasma actuators 10 (PA1 to PA5) may be controlled based on a combination of these two detected values. Furthermore, the plasma actuators 10 (PA1 to PA5) may be controlled based on a combination of three or more detected values.

As an example of controlling the plasma actuators 10 (PA1 to PA5) based on a combination of the above two types of detection values, the plasma actuators 10 (PA1 to PA5) may be driven when the conditions that the "window opening" is equal to or greater than a predetermined value and the "vehicle speed" is equal to or greater than a predetermined value are met, and the plasma actuators PA may not be driven when either the "window opening" or the "vehicle speed" is less than a predetermined value, or when both the "window opening" and the "vehicle speed" are less than a predetermined value.

As a modification of this embodiment, when controlling the plasma actuator 10 based on the vehicle condition values described above, a sound collection sensor (microphone) 205 provided in the vehicle 100 may be used to detect wind throb noise within the vehicle cabin while the vehicle is moving, and the output of the corresponding plasma actuator 10 (plasma actuators PA1 to PA5) may be feedback-controlled in response to changes in the wind throb noise.

In other words, it is preferable that the vehicle 100 in this modified example further includes a sound collection sensor 205 that detects wind throb noise in the vehicle 100, and that the control device 30 controls the output value of the plasma actuator 10 based on the value detected by the sound collection sensor 205.

Furthermore, as another modification of this embodiment, it is also possible to control the plasma actuator 10 using a vehicle environment value in addition to the vehicle status value (step 1-B). For example, it is also possible to control the plasma actuator 10 using the detection values of the window opening as the vehicle status value and the wind speed around the vehicle as the vehicle environment value. In this case, the plasma actuators 10 (PA1 to PA5) may be driven when the condition that the "window opening" is equal to or greater than a predetermined value and the "wind speed around the vehicle" is less than a predetermined value is satisfied, and the plasma actuator 10 may not be driven when the above condition is not satisfied. Alternatively, the output value of the plasma actuator 10 may be increased when the above condition is satisfied, and the output value of the plasma actuator 10 may be decreased when the above condition is not satisfied.

10 Plasma actuator 20 Sensors 30 Drive device 100 Vehicle

Claims (5)

A plasma actuator provided at an open end of a side window or a sunroof ;
a vehicle status detection unit that detects an opening degree of the side window or the sunroof ;
A navigation device;
a control device that drives the plasma actuator when the opening degree of the side window or the sunroof is equal to or greater than a predetermined value to reduce wind throbbing noise in the vehicle;
Equipped with
The control device varies the predetermined value in accordance with a current position of the vehicle detected by the navigation device . The vehicle according to claim 1 , wherein the control device varies the predetermined value when the current position is within a predetermined area or a predetermined location. The vehicle of claim 2 , wherein the predetermined area is a valley or a basin, and the predetermined location is within a tunnel . The control device includes:
when the opening degree of the side window or the sunroof is equal to or greater than the predetermined value and is less than a second predetermined value that is greater than the predetermined value, the output of the plasma actuator is set to a first value;
4. The vehicle according to claim 1 , wherein when the opening degree of the side window or the sunroof is equal to or greater than the second predetermined value, the output of the plasma actuator is set to a second value larger than the first value . a plasma actuator provided at an open end of the window;
a vehicle status detection unit that detects the opening degree of the window;
a vehicle environment detection unit that detects a wind speed around the vehicle when the vehicle is stopped;
a control device that drives the plasma actuator to reduce wind throbbing noise in the vehicle when the opening degree of the window is equal to or greater than a first predetermined value and the wind speed is less than a second predetermined value, and does not drive the plasma actuator when the opening degree of the window is equal to or greater than the first predetermined value and the wind speed is equal to or greater than the second predetermined value;
A vehicle equipped with :