JP4305333B2 - Sound field control apparatus and method - Google Patents

Description

  The present invention relates to a sound field control apparatus and method for controlling a sound field in a passenger compartment.

Conventionally, an alarm device that detects an object position around a vehicle, notifies the driver of the position of the object using a sound image by a speaker, and alerts the driver to the object is known (for example, , See Patent Document 1). In this alarm device, a sound signal in a low frequency band with a long wavelength is used for the sound for locating the sound image position in the left-right direction, and even if the driver's position fluctuates, the change in the sound image is kept small. ing.
Japanese Patent Laid-Open No. 06-55984

  By the way, the position of the driving driver changes according to the driving state of the vehicle. For example, when the vehicle enters the corner, the driver's ear position (ear point) with respect to the vehicle moves from its fixed position due to inertial force. There are things to do. In this case, since the sound field changes relatively depending on the running state of the vehicle, the desired acoustic effect cannot be obtained at the driver's ear position. Such an inconvenience applies not only when an alarm is issued, but also when listening to music in which sounds of a wide range of frequency components are output regardless of whether the frequency is low or when moving the sound image.

  Accordingly, an object of the present invention is to provide a sound field control apparatus and method that can effectively maintain an intended acoustic effect even when a change in the running state of a vehicle occurs.

In order to solve the above problems, according to one aspect of the present invention, there is provided a sound field control device for controlling a sound field in a vehicle compartment formed by sound output means,
A normal function that forms a reference sound field based on the position of the occupant's ear in the normal driving state of the vehicle;
When a change in the running state of the vehicle is predicted, a movement distance at the time of a change in the occupant's ear position caused by the change in the predicted running state is predicted, and the movement distance of the predicted ear position is There is provided a sound field control device having a correction function for correcting a reference sound field.

In this aspect, the change in the traveling state of the vehicle may be predicted in advance based on given map information and traveling information of the vehicle. The change in the running state of the vehicle may be a change factor caused by acceleration in the vehicle front-rear direction or vehicle left-right direction generated in the vehicle .

According to another aspect of the present invention, there is provided a sound field control device for controlling a sound field in a vehicle formed by sound output means,
A running state change prediction means for predicting a change in the running state of the vehicle ;
A travel distance predicting means for predicting a travel distance in the case of a change in an occupant's ear position caused by a change in the travel state predicted by the travel state change predicting means ;
The sound field is controlled in accordance with the prediction result by the traveling state change predicting means, and the travel distance of the occupant's ear position in the passenger compartment accompanying the change in the traveling state of the vehicle is predicted by the traveling distance predicting means. A sound field control device is provided, which is characterized by compensating for the moving distance .

According to another aspect of the present invention, there is provided a sound field control method for controlling a sound field in a vehicle formed by sound output means,
Predicting a change in the running state of the vehicle based on the given map information and the running information of the vehicle;
Predicting the movement distance of the occupant's ear position that occurs when the change in the running state of the vehicle is predicted; and
Changing the sound field control mode according to the predicted movement distance of the occupant's ear position at the time when the change in the running state of the vehicle occurs. Provided.

  ADVANTAGE OF THE INVENTION According to this invention, even when the driving | running | working state change of a vehicle arises, the sound field control apparatus which can maintain a desired acoustic effect effectively, and its method can be obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram showing a main part of a sound field control apparatus according to the present invention. The sound field control device according to the present embodiment is configured with the audio device 40 as the center. The audio device 40 includes an appropriate processor such as a digital signal processor, for example, and digitally processes various audio signals to form a desired sound field that matches the shape of the vehicle interior.

  The audio device 40 is provided integrally with a console upper panel of a vehicle as an audio head unit, for example. The audio device 40 may be embodied as an MD integrated AM / FM electronic tuner, for example. In addition, the audio device 40 may be capable of 5.1ch multi-surround reproduction of a DVD video by incorporating a DVD player.

  For example, a display device 50 such as a VGA display is connected to the audio device 40, and the state of the audio device 40 and the like are displayed on the display device 50. The audio device 40 receives various input signals from the user via various switches and a remote controller.

  A navigation device 60 is connected to the audio device 40. The navigation device 60 measures the position of the vehicle using information from a GPS receiver that receives a GPS (Global Positioning System) signal, a gyro sensor, and the like, and uses the given map data on the display device 50. The vehicle position is superimposed on the map. The given map data includes the coordinate information of each node corresponding to the junction / branch point of the intersection / highway, link information connecting adjacent nodes, road width information corresponding to each link, each link May include road types such as national roads, prefectural roads, and highways, traffic restriction information for each link, traffic restriction information between links, and the like. Further, given map data may be stored in a rewritable storage device such as an HDD, and the contents thereof may be added / updated.

The navigation device 60 includes a CAN (controller area).
Various electronic components in the vehicle are connected via an appropriate bus such as a network. For example, various sensors such as a wheel speed sensor, a steering sensor, and a yaw rate sensor are connected to the navigation device 60.

  FIG. 2 is a functional block diagram showing the main configuration of the audio device 40. The audio device 40 includes a speaker 42, an audio amplifier 44 (power amplifier), a sound field control unit 46, a phase calculation unit 48, and an ear point movement distance calculation unit 49 (hereinafter referred to as “EP movement distance calculation unit 49”). Is provided.

  The speaker 42 is composed of a plurality of speakers (including a tweeter and a woofer) mounted at a predetermined location in the vehicle interior, and the same type of speakers 42 are arranged on the left and right sides to form a pair.

  The sound field control unit 46 controls the sound field in the passenger compartment formed by the sound output from the speaker 42. The sound output from the speaker 42 is a sound that expresses an alarm or music, and the type thereof may be arbitrary. The audio amplifier 44 supplies the amplified audio signal to each speaker 42 based on the phase control information of each speaker 42 (each output channel) from the sound field control unit 46.

  The sound field control unit 46 controls the sound field in the passenger compartment by controlling the output phase (timing) of the sound signal to each of the left and right speakers 42 to realize various acoustic effects. For example, when notifying the user of the position of an obstacle by a warning, not only notifying that there is an obstacle in the right direction by simply outputting from the right speaker 42, but for example shifting the sound field from the whole area to the right side. Thus, it is possible to notify the user of the position of the obstacle in a more easily understandable form. By forming such various acoustic effects, various information (for example, distance to obstacles and risk) can be transmitted to the user using the change in the sound field as a medium.

  By the way, in order to realize such an acoustic effect, it is necessary to perform precise acoustic control (particularly, sound field control centered on the phase). This acoustic control is performed based on the occupant's ear position (ear point), but the ear point is likely to fluctuate due to various disturbances that occur in the vehicle while the vehicle is running. Therefore, when performing acoustic control without considering such fluctuations of the ear point, there is a possibility that a useful acoustic effect that should be obtained by such precise acoustic control may not be obtained.

  Therefore, in this embodiment, as will be described in detail below, a change in the running state of the vehicle that causes the fluctuation of the ear point is predicted based on various information, and the fluctuation of the ear point is appropriately compensated based on the prediction result. By doing so, it is possible to maintain a desired acoustic effect even when the running state of the vehicle changes.

  Specifically, the EP movement distance calculation unit 49 predicts / calculates the movement distance L of the ear point (and the time when the movement occurs) based on the traveling state of the vehicle. The movement distance L of the ear point is defined as a relative movement amount based on the nominal position of the ear point based on the design value (that is, the ear position of the neutral occupant in the vehicle in the neutral position). However, the movement distance L may be appropriately corrected based on information related to the user's physique. Note that the information related to the user's physique may be based on input data by the user, or may be based on an image recognition processing result for a captured image of the in-vehicle camera.

  For example, the EP travel distance calculation unit 49 is based on the speed and acceleration information obtained from the wheel speed sensor and the road shape information on the future route obtained from the map data of the navigation device 60. The travel distance L at that time is predicted and calculated.

  The phase calculation unit 48 converts the movement distance L calculated by the EP movement distance calculation unit 49 using the output sound source wavelength λ (phase conversion value = L / λ).

  The sound field control unit 46 changes the phase of the audio signal for each of the left and right speakers 42 based on the phase conversion value L / λ from the phase calculation unit 48. For example, as shown in FIG. 3, when the ear point is shifted to the left with respect to the nominal position, the phase of the sound output from the left speaker 42 is delayed and the phase of the sound output from the right speaker 42 is advanced. Make it. Thereby, even when it deviates from the nominal position of the ear point, substantially the same acoustic effect as when it is in the nominal position of the ear point can be realized.

  As described above, according to the present embodiment, the phase of the sound output from the left and right speakers 42 is changed in response to the deviation of the ear point, so even if the behavior change of the vehicle occurs, Therefore, the desired acoustic effect intended by precise sound field control can be maintained. Such compensation is useful not only for alarms with precise sound field control as described above, but also for music playback with precise sound field control such as 5.1ch multi-surround reproduction.

  FIG. 4 is a flowchart showing the main operation of the audio apparatus 40 of this embodiment. Here, a description will be given in association with a case where a vehicle passes through a corner as shown in FIG.

  First, when it is detected from the map information and the vehicle position information of the navigation device 60 that the corner as shown in FIG. Road shape information relating to the corner is acquired from the map information (step 100). This road shape information includes the curvature R and cant α of the corner, and may further include the configuration of the corner (the length of a constant curvature section, the length of a clothoid section, etc.).

Next, the EP travel distance calculation unit 49 predicts the speed V during cornering based on the current vehicle speed and acceleration information, and the lateral acceleration Gc (= V ² / R + α / 100) acting on the vehicle during cornering. Is calculated (step 110). The speed V during cornering may be calculated on the assumption that the brake is not operated in a certain curvature section or that a predetermined deceleration is performed up to a predetermined distance before the end point of the clothoid section. At this time, the learning result of the deceleration mode when the user enters the corner may be used. The calculation process of the lateral acceleration Gc is completed at the latest before the vehicle reaches the corner (for example, the start position of the clothoid section) (that is, until the occurrence of the deviation of the ear point). Further, the calculation process of the lateral acceleration Gc is accompanied by calculation of the predicted occurrence time t1 of the lateral acceleration Gc.

  In step 110, if the predicted lateral acceleration Gc is smaller than a predetermined threshold value, it may be determined that there is no need for sound field correction. Alternatively, the EP travel distance calculation unit 49 predicts / calculates the lateral acceleration Gc after a predetermined time from the current time at a predetermined calculation cycle when heading to the corner, and the lateral acceleration Gc exceeds a predetermined value. In this case, the movement distance L of the ear point is calculated based on the lateral acceleration Gc (see next step 120), and the time point after the predetermined time from the current time may be set as the ear point movement start time t1.

Following step 110, the EP movement distance calculation unit 49 calculates the movement distance L of the ear point at the predicted occurrence time t1 of the lateral acceleration Gc based on the predicted lateral acceleration Gc (step 120). In this example, the moving distance L is given by L = Gc × t0 ^2. Here, t0 is a predicted time until the occupant steps on the lateral acceleration Gc, that is, a predicted time until the movement of the ear point is stopped after the lateral acceleration Gc is generated. This t0 may be set as a default value (for example, 0.2 s), or may be variable according to the magnitude of the lateral acceleration Gc. In addition, in order to consider that an appropriate value of t0 may vary depending on the user, data monitored and learned by the in-vehicle camera may be considered. An upper limit L _max may be set for the movement distance L.

  When the EP point movement distance calculation unit 49 calculates the ear point movement distance L in this way, the phase calculation unit 48 performs phase conversion on the calculated movement distance L using the output sound source wavelength λ to obtain a phase. A conversion value L / λ is obtained (step 130).

  When the phase conversion value L / λ is calculated by the phase calculation unit 48 in this way, the sound field control unit 46 applies to each of the left and right speakers 42 based on the calculated phase conversion value L / λ. The phase correction amount and correction timing of the audio signal are determined (step 140). Then, the sound field control unit 46 reaches the occupant's ear starting from the audio signal to be output at the predicted generation time point t1 of the earpoint movement distance L or at the predicted generation time point t1 of the earpoint movement distance L. The execution of phase correction is started from the audio signal (step 150). Thereby, the sound field is appropriately changed in response to the lateral acceleration Gc acting to move the ear point.

  Thereafter, the sound field control unit 46 continues the process of step 140 described above until the predicted time t2 when the lateral acceleration Gc disappears (that is, time t2 when the corner is exited). That is, the sound field control unit 46 ends the phase correction using the audio signal to be output at the predicted time t2 as a starting point or the audio signal reaching the passenger's ear at the predicted time t2. Accordingly, the sound field is appropriately changed in response to the disappearance of the lateral acceleration Gc and the return of the ear point to the original position.

  Note that the sound field control unit 46 may change the phase smoothly or discontinuously at the start and / or end of the phase correction according to the movement mode of the ear point. As an example of the former, stepwise phase correction may be started before the end point of the clothoid interval where movement of the ear point is expected to start, and phase correction may be ended stepwise after the start point of the clothoid interval. Further, when a further large change in the lateral acceleration Gc is predicted during corner traveling, the same phase correction may be executed accordingly.

  As described above, in the present embodiment, the fluctuation of the ear point due to the change in the vehicle behavior is estimated in advance based on information such as the road shape and speed, and after a predetermined travel distance [m] (or a predetermined travel time [s]. Later, the ear point is predicted and a sound field based on the predicted ear point is formed after the predetermined travel distance [m] (or after the predetermined travel time [s]). Thereby, as described above, the fluctuation of the ear point due to the change in the vehicle behavior is compensated, and the usefulness of the sound field control can be enhanced.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the fluctuation of the ear point when the lateral acceleration acts on the vehicle is mainly compensated. However, in the same way, before and after the ear point when the acceleration acts in the front-rear direction. It is also possible to compensate for variations in direction. For example, at the time of deceleration performed in a straight corner section (which may include a part of a clothoid section) as shown in FIG. 5, the deceleration at that time is predicted based on the target corner approach speed, and the predicted deceleration Based on the above, the amount of movement of the earpoint in the front-rear direction and the movement start time are predicted, and the same phase correction is performed from the predicted movement point to compensate for the amount of movement of the earpoint in the front-rear direction. Also good. In this case, the speakers 42 arranged in pairs in the front-rear direction are controlled.

  In the above-described embodiment, an example is given of an event in which the moving state of the ear point is maintained for a relatively long time. However, the moving state of the ear point is only for a short time, such as a sudden lane change. This is also applicable to an event in which the acceleration is not maintained (that is, an event in which an increase or decrease in acceleration occurs within a short time).

  Further, in the above-described embodiment, the movement of the ear point is predicted based on the prediction result of the generation mode of the lateral acceleration (or the longitudinal acceleration). The same applies to the case where the position changes. For example, when a warning is generated according to the proximity to an obstacle during parking assist control, for example, a sound field is formed according to the driver's ear position (predicted position or detected position by a camera, etc.) during back travel May be.

  In the above-described embodiment, the sound field is controlled by feedforward from the viewpoint of responsiveness, but feedback control may be performed especially when a continuous sound field is formed such as when listening to music. Good.

  In the embodiment described above, the movement amount of the ear point and the phase correction amount corresponding to the movement amount of the ear point are calculated from the map information and the travel information of the navigation device 60. However, the map information and the travel information of the navigation device 60 and the phase correction are calculated. A map that associates the quantity may be created and stored in advance, and phase control may be executed using the map. Similarly, in the above-described embodiment, the earpoint movement occurrence predicted time t1 (that is, the phase correction start time t1) is calculated from the map information and the travel information of the navigation device 60, but the phase correction start time t1 is For simplicity, the predicted passage time relative to the start point of the constant curvature section of the corner may be used.

  Further, in the above-described embodiment, among the map information used for calculating the movement amount of the ear point, information that does not exist in the map data of the conventional navigation device 60 or that cannot be downloaded from the information providing service center (for example, cant α And road shape information such as curvature R) may be estimated and calculated in reverse from vehicle speed data and lateral acceleration data when actually traveling on the road, or from image processing results of a CCD camera, etc. It's okay. In this case, these pieces of information are stored in the storage device as map information (road accounting information) so that the information can be used when traveling on the road.

It is a system configuration figure showing the principal part of the sound field control device by the present invention. 3 is a functional block diagram showing a main configuration of an audio device 40. FIG. It is explanatory drawing which shows the movement aspect of an ear point typically. It is a flowchart which shows the main operations of the audio apparatus 40 of a present Example. It is explanatory drawing which shows the time of corner driving | running | working as one scene where the sound field control method of a present Example is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 40 Audio apparatus 42 Speaker 44 Audio amplifier 46 Sound field control part 48 Phase calculation part 49 Ear point movement distance calculation part 50 Display apparatus 60 Navigation apparatus

Claims (5)

A sound field control device for controlling a sound field in a vehicle compartment formed by sound output means,
A normal function that forms a reference sound field based on the position of the occupant's ear in the normal driving state of the vehicle;
When a change in the running state of the vehicle is predicted, a movement distance at the time of a change in the occupant's ear position caused by the change in the predicted running state is predicted, and the movement distance of the predicted ear position is A sound field control device having a correction function for correcting a reference sound field.   The sound field control device according to claim 1, wherein a change in the traveling state of the vehicle is predicted in advance based on given map information and traveling information of the vehicle. The sound field control device according to claim 1, wherein the change in the running state of the vehicle is a change factor caused by acceleration in the vehicle front-rear direction or vehicle left-right direction generated in the vehicle . A sound field control device for controlling a sound field in a vehicle formed by sound output means,
A running state change prediction means for predicting a change in the running state of the vehicle ;
A travel distance predicting means for predicting a travel distance in the case of a change in an occupant's ear position caused by a change in the travel state predicted by the travel state change predicting means ;
The sound field is controlled in accordance with the prediction result by the traveling state change predicting means, and the travel distance of the occupant's ear position in the passenger compartment accompanying the change in the traveling state of the vehicle is predicted by the traveling distance predicting means. A sound field control device characterized by compensating for a moving distance . A sound field control method for controlling a sound field in a vehicle formed by sound output means,
Predicting a change in the running state of the vehicle based on the given map information and the running information of the vehicle;
Predicting the movement distance of the occupant's ear position that occurs when the change in the running state of the vehicle is predicted; and
Changing the control mode of the sound field according to the predicted movement distance of the occupant's ear position at the time when the change in the running state of the vehicle occurs.

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