JP5838962B2 - Sound image localization apparatus and program - Google Patents

Description

  The present invention relates to a sound image localization apparatus that localizes a sound image so as to guide a driver's line of sight in order to realize an appropriate driving operation while the vehicle is traveling.

  Various techniques for ensuring the safety of traveling of vehicles have been proposed. For example, a lane departure prevention device that prevents a lane departure when a vehicle is about to depart from the lane during travel has been proposed (see, for example, Patent Document 1).

  In this apparatus, the lane departure amount is calculated as a predicted value, and whether or not the host vehicle is in a lane departure tendency is detected based on the calculated predicted value. When the host vehicle tends to depart from the lane, an alarm is issued or the vehicle is controlled so as to avoid deviation from the lane.

Japanese Patent No. 3945488

  By the way, the technique described in Patent Document 1 detects whether or not there is a tendency to deviate from the lane. After the tendency to deviate from the lane occurs, a warning is issued or the vehicle is controlled. That is, it is predicted that the behavior of the vehicle will be in a dangerous state, and measures are taken for that.

However, when considering further safe driving, it is important to devise measures to prevent the behavior of the vehicle from becoming dangerous in the first place.
Therefore, the applicant has proposed a device for guiding the driver's line of sight while driving.

  It has been found that the driver's line of sight while driving is poured around the point where the visual momentum is minimized. Therefore, for example, a point (hereinafter referred to as “predictive attention point”) where the driver will turn his gaze after N seconds (for example, five seconds) is predicted, and the sound image is localized at this predicted attention point using the technology of stereophony. Let A “sound image” is a sound source in the sense of hearing that senses the spatial position and the like, and “localize the sound image” means to make the spatial position in the sense of sound of the sound source constant. Therefore, when a sound image is localized at the predicted gazing point, it sounds as if the sound source is at the predicted gazing point (direction and distance). Note that “localization” includes not only the meaning of “constant position” but also the meaning of “position” defined as such, but in this specification, the “localization” is used to avoid the confusion. And the latter is referred to as a “localization position”. Thus, by localizing the sound image at the predicted gazing point, the driver's line of sight can be guided to the predicted gazing point, and the behavior of the vehicle can be stabilized.

  However, such line-of-sight guidance technology also has room for improvement in the following respects. That is, there are cases where it is appropriate and inappropriate to guide the line of sight to the predicted gazing point. In the former case, safe driving is ensured by actively guiding the gaze to the predicted gazing point, and in the latter case, safe driving is ensured by not performing the gaze guidance to the predicted gazing point. For example, when driving in an urban area or the like, there is a high possibility that there are objects such as pedestrians to pay attention to in addition to the predicted gazing point, so it is safe not to guide the line of sight to the predicted gazing point. That is, driving is secured.

  The present invention has been made to solve the above-described problems, and its purpose is to guide the driver's line of sight to the gazing point using the technology of stereophonic sound under an appropriate situation. An object of the present invention is to provide a sound image localization apparatus that can perform line-of-sight guidance.

  The sound image localization apparatus (3) made to achieve the above object, together with an audio system (52) for generating a sound image and a stereophonic system (51) for setting a transfer function for localizing the sound image to the audio system Used.

  Here, the sound image localization device is embodied as a navigation device, for example. At this time, the audio system and the stereophonic sound system are usually provided outside the navigation device. However, you may implement | achieve as invention of the navigation system provided with the navigation apparatus, the audio system, and the stereophonic sound system.

  In the sound image localization apparatus, the execution means (30a) executes sound image localization processing. In this sound image localization processing, a gaze point that tends to be watched by the driver during driving is calculated, and the gaze point is output to the stereophonic sound system to localize the sound image to the gaze point via the audio system. It is. Note that the gaze point is, in other words, that the driver is recommended to gaze while driving.

  Here, particularly in the present invention, the acquisition means (30b) acquires travel-related information that is information related to the travel of the host vehicle. Based on the travel-related information acquired by the acquisition unit, the execution control unit (30c) controls the stop / start of the sound image localization process by the execution unit.

The travel-related information may be surrounding information of the host vehicle or travel information such as the travel speed of the host vehicle.
In this way, when the driver's gaze is guided to the gaze point using the stereophonic technology, gaze guidance to the gaze point can be performed under an appropriate situation.

  The present invention is characterized by each means of the sound image localization apparatus, and each means is usually realized as a program that causes a computer to function. In this sense, it may be realized as an invention of a program for realizing each means.

It is a block diagram which shows schematic structure of a navigation system. It is a flowchart which shows a sound image localization process. It is a flowchart which shows a guidance stop process. It is a flowchart which shows a guidance start process. It is explanatory drawing which shows the lattice point L set virtually on the road. It is explanatory drawing which shows a retinal spherical model. It is explanatory drawing which shows the direction of the eyes | visual_axis when the same driver drive | works the same course by the case where it is not performed when the sound image localization process is performed. It is explanatory drawing which shows the change of the acceleration in the left-right front-back direction of a vehicle when a sound image localization process is performed. It is explanatory drawing which shows the change of the acceleration in the left-right front-back direction of the vehicle when the sound image localization process is not performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A navigation system 1 shown in FIG. 1 is mounted on a vehicle and includes a navigation device 3 and a subsystem 5 controlled by the navigation device 3.

  The navigation device 3 is configured around the control unit 30. The control unit 30 is configured as a so-called computer system, and includes a CPU, a ROM, a RAM, an I / O, and a bus line connecting them.

  The control unit 30 includes a camera 31, a geomagnetic sensor 32, a gyroscope 33, a distance sensor 34, a GPS receiver 35, a map data input unit 36, an operation switch group 37, a communication unit 41, an external memory 42, and a display unit 43. Is connected.

  The camera 31 is a structure for photographing the front of the vehicle. The camera 31 is embodied as a monocular camera or the like. By photographing a predetermined range in front of the vehicle, it becomes possible to detect obstacles such as pedestrians.

  The geomagnetic sensor 32 is configured to detect the direction of the vehicle by geomagnetism. The gyroscope 33 outputs a detection signal corresponding to the angular velocity of the rotational motion applied to the vehicle. Furthermore, the distance sensor 34 outputs the travel distance of the vehicle. The GPS receiver 35 receives a transmission signal from a GPS (Global Positioning System) artificial satellite and detects the position coordinates and altitude of the vehicle. With this configuration, the control unit 30 can calculate the position, direction, and the like of the vehicle. The method for obtaining the position based on the output signal from the GPS receiver 35 may be either a single positioning method or a relative positioning method.

  The map data input unit 36 is a configuration for inputting map data to the control unit 30. The map data is stored in the DVD-ROM 36 a and is input to the control unit 30 via the map data input unit 36. Of course, an HDD or a CD-ROM may be used in addition to the DVD-ROM 36a. The map data includes road data, drawing data, map matching data, route guidance data, and the like.

  The operation switch group 37 is configured to input various instructions from the user, and is embodied as a physical push button switch or the like. Alternatively, it may be embodied as a touch panel configured integrally with the display unit 43.

  The communication unit 41 is a configuration for performing inter-vehicle communication with other vehicles around the host vehicle. Thereby, for example, if there is a request from another vehicle, the control unit 30 can transmit the position information (the own vehicle position and altitude) of the own vehicle to the other vehicle.

  The external memory 42 is a memory that enables temporary storage. For example, it may be configured by a flash memory or the like so that stored contents are not lost even when the power is turned off. Moreover, you may comprise by HDD etc.

  The display unit 43 is configured by, for example, a liquid crystal display. The display unit 43 displays a map based on the map data input via the map data input unit 36 and the vehicle position on the map. When a route to the destination is searched, the route can be displayed.

The subsystem 5 includes a stereophonic sound system 51 and an audio system 52.
The stereophonic sound system 51 instructs the audio system 52 to set a transfer function in order to localize the sound image. Specifically, the setting of the transfer function is instructed based on the command value output from the control unit 30, as will be described later. The transfer function is used in a well-known sound image localization technique, and more specifically, is a head-related transfer function (HRTF) that represents a transfer characteristic of sound from the virtual sound source to the eardrum of the listener.

The audio system 52 includes a sound source 53, filters 54L and 54R, and speakers 55L and 55R.
The sound source 53 is embodied as a CD sound source or a radio sound source. Note that recording by the user may be used as a sound source, or an alarm sound or the like may be used as a sound source. These sound sources 53 can be switched via the operation switch group 37 of the navigation device 3.

  One of the speakers 55L and 55R is a left speaker 55L for outputting sound from the left side of the user, and the other is a right speaker 55R for outputting sound from the right side of the user.

  The left filter 54L corresponds to the left speaker 55L, and the right filter 54R corresponds to the right speaker 55R. As described above, when the sound image is localized, the left filter 54L and the right filter 54R perform filtering based on the transfer function. The signals from the sound source 53 filtered in this way are output to the left speaker 55L and the right speaker 55R, respectively.

  Note that the left speaker 55L and the right speaker 55R are two channels, and the left speaker 55L and the right speaker 55R may each be composed of a plurality of speakers. Further, in a normal time when line-of-sight guidance described later is not performed, signal output from the sound source 53 is performed based on the audio environment set by the user. At this time, the audio system 52 outputs a signal without passing through the filters 54L and 54R.

  The audio environment may be an equalizer setting that changes the frequency characteristics of the output signal. It is also possible to set the left and right balance. When speakers are arranged in the front-rear direction, setting of the front-rear balance is also included. The setting of the audio environment is performed via the operation switch group 37 and stored in the external memory 42 of the navigation device 3. It is assumed that the default audio environment is stored in the external memory 42 when the setting is not made by the user.

  In addition, an ECU group 60 in the vehicle is connected to the control unit 30 via a network such as an in-vehicle LAN. The control unit 30 can acquire the vehicle speed acquired by, for example, a wheel speed sensor by communicating with a plurality of ECUs constituting the ECU group 60.

  Next, sound image localization processing will be described based on the flowchart of FIG. By executing this sound image localization processing, the sound image is localized at the predicted gazing point, and the driver's line of sight can be guided to the predicted gazing point. The sound image localization process is repeatedly executed by the control unit 30 at a predetermined time interval (for example, 300 ms) when the line-of-sight guidance mode is “ON” or “AUTO”.

  The line-of-sight guidance mode is for selecting and instructing whether or not to perform the driver's line-of-sight guidance by executing sound image localization processing. The line-of-sight guidance mode includes “ON”, “AUTO”, and “OFF”. . In the case of the line-of-sight guidance mode “ON”, sound image localization processing is basically executed. Further, when the line-of-sight guidance mode is “OFF”, the sound image localization process is not executed. Furthermore, in the case of the line-of-sight guidance mode “AUTO”, execution of the sound image localization process is determined based on various travel-related information.

In first S100, the speed of the host vehicle is acquired. In this process, the current speed of the host vehicle is acquired via the ECU group 60.
In continuing S110, the position of the own vehicle is acquired. This process uses the geomagnetic sensor 32 and the GPS receiver 35 to calculate the position and orientation of the host vehicle, and further uses road data and map matching data in the map data input via the map data input unit 36. The position of the vehicle on the map is acquired.

  In the next S120, the road shape is acquired. In this process, the shape of the road on which the host vehicle is traveling is acquired based on the position of the host vehicle acquired in S110. As will be described later, in order to estimate the position of the host vehicle after N seconds, a road shape within a predetermined range (for example, up to 50 m ahead) is acquired in consideration of the traveling direction.

  In subsequent S130, the curvature of the road at the position of the host vehicle after N seconds is acquired. This process acquires the curvature of the road at the estimated position of the host vehicle when traveling for N seconds at the speed of the host vehicle acquired in S100.

  In the next S140, the speed and yaw rate of the host vehicle after N seconds are estimated. The yaw rate is the rate of change of the rotation angle in the turning direction of the host vehicle. Here, the speed of the host vehicle acquired in S100 is set as the speed of the host vehicle after N seconds, and the yaw rate of the host vehicle is estimated based on the curvature of the road acquired in S130.

  In subsequent S150, a command value is calculated. This process calculates a command value indicating a predicted point of gaze at the position of the host vehicle after N seconds. The predicted gazing point can be calculated by the method described in Japanese Patent No. 4735676. This command value is calculated as, for example, the distance R to the predicted gazing point, the azimuth angle θ that is the horizontal angle from the host vehicle, and the elevation angle φ that is the vertical angle from the host vehicle.

  In the next S160, a localization position which is a target of sound image localization based on the command value is output. In this process, the localization position of the sound image in the three-dimensional orthogonal coordinate system is calculated based on the command value calculated in S150, and the localization position is output to the stereophonic sound system 51. Thereby, the stereophonic sound system 51 instructs the audio system 52 to set the transfer function used in the filters 54L and 54R. For example, the audio system 52 holds a plurality of transfer functions corresponding to instructions from the stereophonic sound system 51 in advance, and selectively sets the transfer functions. Thereby, the sound image formed by the speakers 55L and 55R is localized at the localization position corresponding to the command value.

By such sound image localization processing, the sound image is localized at the predicted gazing point, which is the gazing point at the vehicle position after N seconds.
As shown in FIG. 7, when the driver's line-of-sight direction (angle) with the front direction as 0 degrees is the vertical axis and the measurement time is the horizontal axis, the movement of the driver's line-of-sight when sound image localization processing is performed is As shown by curve A (curve shown by a thick solid line). On the other hand, the movement of the driver's line of sight when the sound image localization processing is not executed is as shown by a curve B (curve indicated by a thin solid line). At this time, a curve X (curve indicated by a broken line) indicates a change in the direction of the predicted gazing point.

  As can be seen from FIG. 7, the direction of the driver's line of sight increases due to the execution of the sound image localization process, and tends to be similar to the change in the direction of the predicted gazing point. Thereby, when the sound image localization processing is executed, it is understood that the driver's line of sight is guided in the direction of the predicted gazing point, and the driver is carrying the line of sight toward the back of the corner on the road.

FIGS. 8 and 9 plot the longitudinal and lateral accelerations of the vehicle on the vertical axis and the horizontal axis, respectively, when the sound image localization process is executed and when it is not executed. Here, in FIG. 9, which shows the time when the sound image localization processing is not executed, the magnitude and direction of the acceleration change abruptly, whereas in FIG. 8, which shows the time when the sound image localization processing is executed, The change in size and direction became continuous and smooth. As a result, when the line-of-sight guidance mode is turned on, the driver's line of sight is guided in the direction of the predicted gazing point, and as a result, a driving operation that smoothens the behavior of the vehicle is realized.

  However, there are cases where it is appropriate and inappropriate to guide the line of sight to the predicted gazing point. In the former case, safe driving is ensured by actively guiding the gaze to the predicted gazing point, and in the latter case, safe driving is ensured by not performing the gaze guidance to the predicted gazing point.

Therefore, in the present embodiment, the following guidance stop processing and guidance start processing are executed. Hereinafter, these processes will be described.
The guidance stop process shown in the flowchart of FIG. 3 is repeatedly executed by the control unit 30 at predetermined time intervals when the line-of-sight guidance mode is set to “ON” or “AUTO”. The reason why the line-of-sight guidance mode is also “ON” is to eliminate problems caused by executing the sound image localization process under an inappropriate situation.

  In first S200, it is determined whether or not driving support control is being performed. This process determines whether or not a control system that supports driving is operating, and is performed based on information from the ECU group 60. For example, it is determined whether an inter-vehicle automatic control system called ACC (Adaptive Cruise Control) and a lane keep assist system called LKA (Lane Keeping Assist System) are operating. When it is determined that the driving support control is being performed (S200: YES), the process proceeds to S210. On the other hand, when it is determined that the driving support control is not being performed (S200: NO), the process of S210 is not executed, and the process proceeds to S220.

  In S210, it is determined whether or not there is an override. This process determines whether or not there has been a driver's operation intervention during the driving support control. The operation intervention means an accelerator operation, a brake operation, a steering operation, or an operation for stopping (turning off) the driving support control. When there is a driver's operation intervention, it is considered that a driving situation that requires attention has occurred. If it is determined that there is an override (S210: YES), the sound image localization process is stopped in S280, the stop of the process is notified in S290, and then the guidance stop process is terminated. The process stop notification is a notification such as “Sound guidance stopped” (and so on). On the other hand, when it is determined that there is no override (S210: NO), the process proceeds to S220.

  In S220, it is determined whether the vehicle is traveling in an urban area. This process is based on the map data input via the map data input unit 36, and determines whether or not the road on which the vehicle travels is an urban road. The determination as to whether or not it is an urban area is made by, for example, determining the area of the facility from POI (Point Of Interest) data and determining the floor area ratio of the area around the vehicle on the map. If it is determined that the vehicle is traveling in an urban area (S220: YES), the sound image localization process is stopped in S280, the stop of the process is notified in S290, and then the guidance stop process is terminated. This is because there are many objects such as pedestrians that require attention in urban areas. On the other hand, when it is determined that the vehicle is not traveling in an urban area (S220: NO), the process proceeds to S230.

In S230, it is determined whether or not the low speed running is continued. Here, for example, it is determined that the vehicle is traveling for 10 seconds at a speed of 10 km / h or less. The vehicle speed of the host vehicle is acquired via the ECU group 60. If it is determined that the low-speed running is continued (S230: YES), the sound image localization process is stopped in S280, the process stop is notified in S290, and then the guidance stop process is ended. This is because there is a high probability that there are many objects such as pedestrians to pay attention to even if the vehicle is traveling at low speed, even in a city area. On the other hand, when it is determined that the low-speed traveling is not continued (S230: NO), the process proceeds to S240.

  In S240, it is determined whether or not the vehicle is stopped. This process is to determine whether or not the vehicle speed of the host vehicle is “0”. If it is determined that the vehicle is stopped (S240: YES), the sound image localization process is stopped in S280, the process stop is notified in S290, and then the guidance stop process is terminated. When stopped, the localization of the sound image based on the shape of the road ahead makes no sense, distracting the driver's attention and causing a sense of discomfort, such as `` you can hear the sound from the right side even if it stops '' This is because On the other hand, when it is determined that the vehicle is not stopped (S240: NO), that is, when the vehicle is running, the process proceeds to S250.

  In S250, it is determined whether the sound image localization process is stopped. If it is determined that the sound image localization process is stopped (S250: YES), the sound image localization process is started in S260, the start of the process is notified in S270, and then the guidance stop process is terminated. . The notification of the start of the process is a notification such as “The guidance by sound has started” (and so on). On the other hand, when it is determined that the sound image localization process is not stopped (S250: NO), that is, when the sound image localization process is repeatedly executed, the processes of S260 and S270 are not executed, and the guidance stop process is terminated. .

The guidance start process shown in the flowchart of FIG. 4 is repeatedly executed by the control unit 30 at predetermined time intervals when the line-of-sight guidance mode is set to “AUTO”.
In first S300, it is determined whether or not the vehicle is traveling on a highway. This determination is made based on the map data input via the map data input unit 36. If it is determined that the vehicle is traveling on a highway (S300: YES), the sound image localization process is started in S310, the start of the process is notified in S320, and the guidance start process is then terminated. On the other hand, when it is determined that the vehicle is not traveling on the highway (S300: NO), the processes of S310 and S320 are not executed, and the guidance start process is terminated.

  As described above in detail, in the present embodiment, in parallel with the sound image localization process (see FIG. 2), the guidance stop process (see FIG. 3) and the guidance start process (see FIG. 4) are executed, thereby predicting the gaze point. It is determined whether it is an appropriate situation or an inappropriate situation to guide the line of sight to the sound, and the stop / start of the sound image localization process is controlled.

  That is, by the sound image localization process executed by the execution unit 30a, a gaze point that tends to be watched by the driver while traveling is calculated, and the gaze point is output to the stereophonic sound system, thereby the audio system is The sound image is localized at the point of interest.

  Here, in particular, the acquisition unit 30b acquires travel-related information that is information related to the travel of the host vehicle, and the execution control unit 30c is based on the travel-related information acquired by the acquisition unit 30b. Controls stop / start of sound image localization processing.

Thereby, in guiding the driver's line of sight to the gazing point using the stereophonic technology, the line of sight to the gazing point can be performed under an appropriate situation.
In the present embodiment, the speed of the host vehicle is acquired (S100 in FIG. 2), and the position of the host vehicle on the map is acquired (S110). Next, the road shape within a predetermined range is acquired in consideration of the traveling direction (S120), the curvature of the road at the position of the host vehicle after N seconds is acquired (S130), and the speed of the host vehicle after N seconds and A yaw rate is estimated (S140), and a command value indicating a predicted gazing point at the position of the host vehicle after N seconds is calculated (S150). That is, in the sound image localization processing, the future speed and yaw rate of the vehicle are estimated, and a predicted gazing point that is the gazing point in the future is calculated. As a result, a predicted gazing point that the driver is gazing in the near future is calculated, so that the driving operation of the driver can be made more appropriate by localization of the sound image to the predicted gazing point.

  By the way, it is thought that the driving | running | working condition which should pay attention has generate | occur | produced when there exists a driver | operator's operation intervention during driving assistance control, such as ACC and LKA. In this respect, in the present embodiment, it is determined whether or not the driving support control is being performed (S200 in FIG. 3), and when the driving support control is being performed by the driving support system (S200: YES), by the driver. If there is an override (S210: YES), the sound image localization process is stopped (S280). That is, it is used together with a driving support system that supports driving of the host vehicle, the acquisition unit 30b acquires the control state of the host vehicle by the driving support system as travel related information, and the execution control unit 30c is based on the control state, If there is a driver's operation intervention in the control by the driving support system, the sound image localization processing is stopped. Thereby, sufficient attention can be paid to the driving situation, which contributes to the realization of safe driving.

  In addition, there are many objects such as pedestrians that require attention in urban areas. In this regard, in this embodiment, it is determined whether or not the vehicle is traveling in an urban area (S220 in FIG. 3), and if it is determined that the vehicle is traveling in an urban area (S220: YES), the sound image localization process is stopped. (S280). That is, the acquisition unit 30b acquires the road on which the host vehicle travels as travel-related information, and the execution control unit 30c stops the sound image localization process when the host vehicle is traveling in an urban area based on the road. Thereby, sufficient attention can be paid to the object, which contributes to the realization of safe driving.

  Furthermore, when low-speed driving continues, there is a high probability that there are many objects to be paid attention to, such as pedestrians, even in a city area. In this regard, in the present embodiment, it is determined whether or not the low-speed traveling of the host vehicle is continued (S230 in FIG. 3), and when it is determined that the low-speed traveling is continued (S230: YES). Then, the sound image localization process is stopped (S280). That is, the acquisition unit 30b acquires the speed of the host vehicle as the travel-related information, and the execution control unit 30c stops the sound image localization process when the host vehicle continues to travel at a low speed based on the speed. Thereby, sufficient attention can be paid to the object, which contributes to the realization of safe driving.

  Also, when stopped, the localization of the sound image based on the shape of the road ahead makes no sense, distracting the driver's attention and causing a sense of incongruity, such as `` you can hear the sound from the right side even if it stops '' I will let you. In this regard, in the present embodiment, it is determined whether or not the own vehicle is stopped (S240 in FIG. 3), and if it is determined that the own vehicle is stopped (S240: YES), the sound image is displayed. The localization process is localized (S280). That is, the acquisition unit 30b acquires the speed of the host vehicle as the travel-related information, and the execution control unit 30c stops the sound image localization process when the host vehicle is stopped based on the speed. As a result, the driver's attention is not distracted or uncomfortable while the vehicle is stopped.

  On the other hand, when the host vehicle is traveling on an expressway, turning the line of sight toward the back of the corner leads to stable vehicle behavior. In this regard, in this embodiment, it is determined whether or not the host vehicle is traveling on the expressway (S300 in FIG. 4), and if it is determined that the vehicle is traveling on the expressway (S300: YES). ), Sound image localization processing is started (S310). That is, the acquisition unit 30b acquires the road on which the host vehicle travels as travel-related information, and the execution control unit 30c starts the sound image localization process when the host vehicle is traveling on the highway based on the road. . As a result, the vehicle behavior can be stabilized in traveling on the highway.

In this embodiment, when the sound image localization process is stopped or started, the stop / start of the process is notified (S270, S290 in FIG. 2, S320 in FIG. 3). That is, a notification unit 30d that notifies the driver of the stop / start of the sound image localization process by the execution unit 30a is provided. This prevents the driver from feeling uncomfortable due to the stop / start of the sound image localization process.

  In this embodiment, a two-channel stereophonic technology is used. On the other hand, if the number of channels is increased and the speakers of the audio system are arranged around the driver, the sound image can be localized without using the stereophonic technology. However, it is difficult to place a speaker at an arbitrary position in a limited space such as a passenger compartment. Therefore, it is very effective to use the two-channel stereophonic technology in the passenger compartment.

As described above, the present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the technical scope thereof.
[Supplemental explanation]
Specifically, the method of calculating the predicted gazing point is performed as follows.

  First, as shown in FIG. 5, dividing lines K are set at regular intervals on the road R on which the host vehicle 100 travels with reference to the host vehicle 100 N seconds after the current time. Then, a plurality of grid points L are virtually set on the dividing line K. Here, the position and distance of each grid point L are acquired from the map data input via the map data input unit 36 of the navigation device 3. In the drawing, a part of the lattice points L set on the dividing line K is shown. The number of grid points L is also an image.

  Next, the change rate of the driver's swing angle after N seconds is estimated. The change rate of the swing angle can be estimated from the curvature of the road acquired in S130 in FIG. The description will be continued assuming that the change rate of the swing angle estimated here is A.

  Subsequently, with respect to the host vehicle 100 after N seconds, a momentum (hereinafter referred to as “visual momentum”) when each lattice point L is projected onto the retinal spherical model is calculated. As shown in FIG. 6, the retinal spherical model is obtained by modeling the driver's retina as a spherical surface, and the position of the object on the retinal spherical model corresponds to the position in the retinal coordinate system.

  Here, if the azimuth angle of the object is θ and the elevation angle is φ, the position on the retinal spherical model of an arbitrary lattice point L with reference to the vehicle 100 after N seconds can be described as (θ, φ). it can. Then, the absolute value of the change rate of the eccentric angle ω (eccentric angle change rate ω ′) is calculated as the visual momentum. The eccentric angle change rate ω ′ can be expressed by the following equation 1 where the vehicle speed is V, the distance to the lattice point L is R, and the yaw rate is γ. The vehicle speed V and the yaw rate γ are those estimated in S140 in FIG.

The eccentric angle change rate ω ′ is calculated for each lattice point L using Equation 1, and the lattice point L at which the absolute value of the eccentric angle change rate ω ′ is the minimum is set as the predicted gazing point after N seconds.
Since the eccentric angle change rate ω ′ is calculated using the retinal spherical model, it indicates the visual momentum of the lattice point L on the road. It is known that the driver tends to gaze at the minimum point of visual momentum during driving.

[Other Embodiments]
(A) In the above embodiment, the guidance stop process is executed when the line-of-sight guidance mode is “ON” or “AUTO”, and the guidance start process is executed when the line-of-sight guidance mode is “AUTO”. The guidance stop process is executed when the line-of-sight guidance mode is “ON” based on the state where there is no line-of-sight guidance due to localization of the sound image, even when it is clearly “ON” The following is based on the judgment that it is appropriate to stop the sound image localization processing. However, the guidance stop process may be executed only when the line-of-sight guidance mode is “AUTO”. Similarly, when the line-of-sight guidance mode is “OFF”, the guidance start process is not executed when the line-of-sight guidance by sound image localization is not used as a reference and is clearly “OFF” Is based on the judgment of respecting the driver's will even under appropriate circumstances. However, the guidance start process may be executed when the line-of-sight guidance mode is “OFF” or “AUTO”.

  (B) In the above embodiment, the command value corresponding to the predicted gazing point is calculated based on the position of the host vehicle N seconds after the current time (S150 in FIG. 2). On the other hand, the command value corresponding to the predicted gazing point may be calculated on the basis of the position of the host vehicle that has traveled by a predetermined distance M (for example, 30 m) from the present time. In this case, in S130 of the sound image localization process shown in FIG. 2, the curvature at a position advanced by a predetermined distance M from the current position of the host vehicle may be acquired. Even if it does in this way, the same effect as the above-mentioned embodiment is produced.

  (C) In the above embodiment, the command value corresponding to the predicted gazing point is calculated based on the position of the host vehicle N seconds after the current time (S150 in FIG. 2). On the other hand, the current gaze point may be calculated. In this case, in S130 of the sound image localization process shown in FIG. 2, the curvature of the road at the present time of the host vehicle may be acquired. Even if it does in this way, the same effect as the above-mentioned embodiment is produced.

  DESCRIPTION OF SYMBOLS 1 ... Navigation system, 3 ... Navigation apparatus, 5 ... Subsystem, 30 ... Control part, 30a ... Execution means, 30b ... Acquisition means, 30c ... Execution control means, 30d ... Notification means, 31 ... Camera, 32 ... Geomagnetic sensor, 33 ... Gyroscope, 34 ... Distance sensor, 35 ... GPS receiver, 36a ... DVD-ROM, 37 ... Operation switch group, 41 ... Communication unit, 42 ... External memory, 43 ... Display unit, 51 ... Stereophonic sound system, 52 ... Audio system, 53 ... Sound source, 54L ... Filter, 54L ... Left filter, 54R ... Right filter, 55L ... Speaker, 55L ... Left speaker, 55R ... Right speaker, 60 ... ECU group, 100 ... Own vehicle

Claims (8)

Used together with an audio system (52) for generating a sound image and a stereophonic system (51) for setting a transfer function for localizing the sound image to the audio system;
A sound image localization process is performed for calculating a gazing point that the driver tends to gaze while traveling and outputting the gazing point to the stereophonic sound system to localize the sound image to the gazing point via the audio system. A sound image localization device (3) provided with execution means (30a) for executing,
Acquisition means (30b) for acquiring travel-related information that is information related to the travel of the host vehicle;
Execution control means (30c) for controlling stop / start of the sound image localization processing by the execution means based on the travel-related information acquired by the acquisition means;
Equipped with a,
In the sound image localization processing, the future speed and yaw rate of the host vehicle are estimated, and a predicted gazing point that is the gazing point in the future is calculated (S140, S150).
A sound image localization device characterized by. The sound image localization apparatus according to claim 1 ,
Used with a driving support system that supports driving of the vehicle,
The acquisition means acquires a control state of the host vehicle by the driving support system as the travel related information,
The execution control means stops the sound image localization processing based on the control state when there is a driver's operation intervention in the control by the driving support system (S200: YES, S210: YES, S280).
A sound image localization device characterized by. The sound image localization apparatus according to claim 1 or 2 ,
The acquisition means acquires a road on which the host vehicle travels as the travel-related information,
The execution control means stops the sound image localization process when the host vehicle is traveling in an urban area based on the road (S220: YES, S280).
A sound image localization device characterized by. In the sound image localization apparatus according to any one of claims 1 to 3 ,
The acquisition means acquires the speed of the host vehicle as the travel-related information,
The execution control means stops the sound image localization process based on the speed when the host vehicle continues traveling at a low speed (S230: YES, S280).
A sound image localization device characterized by. In the sound image localization apparatus according to any one of claims 1 to 4 ,
The acquisition means acquires the speed of the host vehicle as the travel-related information,
The execution control means stops the sound image localization process based on the speed when the host vehicle is stopped (S240: YES, S280).
A sound image localization device characterized by. In the sound image localization apparatus according to any one of claims 1 to 5 ,
The acquisition means acquires a road on which the host vehicle travels as the travel-related information,
The execution control means starts the sound image localization process based on the road when the host vehicle is traveling on an expressway (S300: YES, S310).
A sound image localization device characterized by. In the sound image localization apparatus according to any one of claims 1 to 6 ,
Furthermore, it has a notification means (30d) for notifying the driver of the stop / start of the sound image localization process by the execution means (S270, S290, S320).
A sound image localization device characterized by. Program for causing a computer to function as each means of the sound image localization apparatus according to any one of claims 1-7.