JP7108973B2 - Vehicle proximity notification device - Google Patents

Description

The present invention relates to an approaching vehicle notification system.

For example, a vehicle using an electric motor as a driving source, such as an electric vehicle or an electric hybrid vehicle, generates almost no noise when running at a low speed compared to an engine vehicle. For this reason, low-noise vehicles such as electric vehicles and electric-electric hybrid vehicles emit a vehicle approaching sound in order to notify pedestrians outside the vehicle of the approach of the vehicle, as disclosed in Patent Document 1, for example. It is known that a vehicle approaching audible alarm device is mounted.

According to the device disclosed in Patent Document 1, when the vehicle speed of the vehicle falls below a first threshold, a vehicle approaching sound is generated, and when the vehicle falls below a second threshold smaller than the first threshold, By muting the vehicle approaching sound in a predetermined fade-out time, it is possible to reduce the difference between the fade-out time and the time until the vehicle actually stops regardless of the driving state of the vehicle. Fade-out in this example means that the vehicle approaching sound gradually becomes smaller over a predetermined period of time until the vehicle approaching sound is completely silenced.

In particular, by setting the fade-out time using the deceleration when the vehicle speed is decelerated to the second threshold value, which is the vehicle speed at which the fade-out starts, as a representative value, the brake OFF operation is performed during the time when the vehicle speed is decelerated from the first threshold value to the second threshold value. The fade-out time can be uniquely set even when an accelerator ON operation or the like is performed. On the other hand, after the fade-out starts, the fade-out time is reset when the vehicle accelerates.

JP 2014-88123 A

However, in the above example, if the fade-out time is set before the vehicle stops when the vehicle speed has decelerated to the second threshold, the fade-out will be completed before the vehicle stops when the deceleration becomes gentle in the area below the second threshold. Alternatively, there is a concern that the sound pressure of the approaching sound becomes too small, and the vehicle approaching to the outside cannot be appropriately detected.

The present invention has been made to solve the above problems, and its object is to provide a vehicle capable of outputting an approaching sound at an appropriate sound pressure even if the amount of brake operation changes at a vehicle speed below a threshold. It is to provide an approach notification device.

In order to achieve the above object, the approaching vehicle audible system according to the present invention emits an approaching sound with a predetermined sound pressure to the surroundings of the vehicle by means of a sound output device provided in the vehicle when the vehicle speed of the vehicle drops below a predetermined vehicle speed. and outputting a first approaching sound pressure control for outputting a first approaching sound, and a sound pressure of the first approaching sound a second approach sound pressure control for outputting a second approach sound having a sound pressure different from that of the second approach sound pressure control; The first approach sound pressure control or the second approach sound pressure control is executed when the vehicle speed is less than the predetermined threshold, and the vehicle is configured to perform the first approach sound pressure control or the second approach sound pressure control when the vehicle speed is less than or equal to the predetermined threshold. is configured to transition from the first approach sound pressure control to the second approach sound pressure control when a predetermined amount of braking operation is input to brake the In this state, when the operation amount of the braking operation for braking the vehicle reaches a first predetermined amount, transition is made to the first approach sound pressure control, and the first approach sound pressure control is executed. When the operation amount becomes equal to or greater than a second predetermined amount that is larger than the first predetermined amount in the state where the sound pressure control is on, transition is made to the second approach sound pressure control .

According to the approaching vehicle audible device according to the present invention, it is possible to output an approaching sound with appropriate sound pressure even if the amount of brake operation changes at a vehicle speed equal to or lower than a threshold value.

1 is a block diagram showing the configuration of a vehicle notification approaching device according to the present invention; FIG. 2 is a graph showing characteristics of a sound pressure map stored in the sound pressure map storage unit of FIG. 1, where the horizontal axis indicates vehicle speed and the vertical axis indicates sound pressure. FIG. 2 is a flow chart showing a control flow of the approaching vehicle audible system of FIG. 1; FIG. A graph (time chart) showing the state of outputting an approaching sound when the vehicle is running using the vehicle approach notification device of FIG. (c) shows the sound pressure of the approximating sound with respect to time.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an approaching vehicle audible system 1 according to the present invention will be described below with reference to the drawings (FIGS. 1 to 4).

The approaching vehicle audible device 1 of this embodiment outputs an approaching sound of a predetermined sound pressure to the surroundings of the vehicle from the speaker 2 provided in the vehicle when the vehicle speed of the vehicle becomes equal to or less than a predetermined vehicle speed, thereby warning the vehicle of approaching. It is a device that can notify the surroundings of the vehicle. As shown in FIG. 1, the approaching vehicle audible device 1 includes a receiving unit 11 for receiving signals from the outside, a sound pressure map storage unit 12, a sound pressure calculation unit 15, an approaching sound type storage unit 13, a sound pressure A control unit 14 is provided. A vehicle equipped with the approaching vehicle audible device 1 is provided with a brake operation amount detector 3 , a vehicle speed detector 4 , and a speaker 2 .

The brake operation amount detection unit 3 is a portion that detects the amount of brake operation (braking operation) and detects the amount of brake depression. The greater the operation amount, the greater the degree of deceleration of the vehicle speed. For example, sudden braking is to perform a braking operation with a large amount of operation in a short period of time. The amount of operation is obtained by detecting the amount of pedal stroke, the amount of stroke of the master cylinder, the strength of the force applied to the pedal (operation force), and the like.

The brake operation amount detector 3 is electrically connected to the receiver 11 of the approaching vehicle audible system 1 . The operation amount information detected by the brake operation amount detection unit 3 is converted into an electric signal, sent to the reception unit 11 , and sent from the reception unit 11 to the sound pressure calculation unit 15 . In this example, the brake operation amount detection unit 3 is set to be able to transmit the operation amount information converted into the electric signal to the reception unit 11 at all times.

The vehicle speed detection unit 4 has a function of detecting the traveling speed (vehicle speed) of the vehicle. The vehicle speed detector 4 is electrically connected to the receiver 11 of the approaching vehicle audible system 1 . Vehicle speed information detected by the vehicle speed detector 4 is converted into an electric signal and sent to the receiver 11 . The vehicle speed detection unit 4 is set so as to be able to transmit the vehicle speed information converted into an electrical signal to the reception unit 11 at all times.

The speaker 2 is a device that outputs sound to the outside of the vehicle, and is attached to, for example, the front portion of the vehicle body. The speaker 2 is electrically connected to the sound pressure control section 14 of the approaching vehicle audible system 1 .

Next, the configuration of the approaching vehicle audible device 1 will be described. The receiving unit 11 is electrically connected to the vehicle speed detecting unit 4 and the brake operation amount detecting unit 3 as described above, and can always receive vehicle speed information and operation amount information. The receiver 11 is also electrically connected to the sound pressure calculator 15 .

The sound pressure map storage unit 12 stores a plurality of sound pressure maps. In this embodiment, three sound pressure maps (sound pressure map A, sound pressure map B, and sound pressure map C) are stored. Here, the sound pressure map will be explained using FIG. The sound pressure map defines sound pressure characteristics with respect to vehicle speed, and is a function that uniquely determines sound pressure values with respect to vehicle speed.

The vehicle speed ranges from "zero vehicle speed" when the vehicle is stopped to a speed at which the vehicle can run. For example, the line M1 in the graph of FIG. 2 indicates the characteristics of the sound pressure map A, and the sound pressure increases as the vehicle speed increases. The vehicle speed and the sound pressure in the sound pressure map A have a linear relationship. In this example, as indicated by P0 in FIG. 2, when the vehicle speed is zero, the sound pressure is not zero, but a relatively low sound pressure is set.

A line M2-1 in FIG. 2 indicates the characteristics of the sound pressure map B, and the rate of increase in sound pressure with respect to an increase in vehicle speed is smaller than that in the sound pressure map A. FIG. Similarly to the sound pressure map A, the vehicle speed and the sound pressure in the sound pressure map B also have a linear relationship. Similar to the sound pressure map A, the sound pressure when the vehicle speed is zero in the sound pressure map B is the sound pressure P0. A line M3 in FIG. 2 indicates the characteristics of the sound pressure map C. As shown in FIG. In the sound pressure map C, even if the vehicle speed increases, the sound pressure takes a substantially constant value at the sound pressure P0.

The sound pressure calculator 15 is electrically connected to the receiver 11 , the sound pressure map storage 12 , the approaching sound type storage 13 and the sound pressure controller 14 . The sound pressure calculation unit 15 receives the vehicle speed information and the operation amount information transmitted from the reception unit 11, and based on these information, selects one from a plurality of sound pressure maps stored in the sound pressure map storage unit 12. Select one sound pressure map. Also, the sound pressure is calculated based on the selected sound pressure map and the vehicle speed information. Further, the sound pressure calculation unit 15 reads the types of approach sounds from the approach sound type storage unit 13 and selects the type of approach sounds. Information on the calculated sound pressure and information on the selected approaching sound type are sent to the sound pressure control unit 14 .

The approach sound type storage unit 13 stores sound source information of a plurality of approach sound types. The approximating sound information is stored as approximating sound waveform information. The approaching sound type storage unit 13 is electrically connected to the sound pressure control unit 14 . In the present embodiment, approaching sound types corresponding to sound pressure map A, sound pressure map B, and sound pressure map C are set. Species can be set.

The sound pressure control section 14 is electrically connected to the sound pressure calculation section 15 . Also, the sound pressure control unit 14 is electrically connected to the external speaker 2 . The sound pressure controller 14 controls the sound pressure of the approaching sound output from the speaker 2 based on the sound pressure calculated by the sound pressure calculator 15 .

Next, the control of the approaching vehicle audible system 1 of this embodiment will be described with reference to the flow chart of FIG. 3 and the time chart of FIG. FIG. 4 shows an example controlled by the flow chart of FIG.

At the start (step S1) shown in FIG. 3, the vehicle is running, which corresponds to the region T0 shown in FIG. 4(a). As shown in FIG. 4, in the area T0 corresponding to the "start" of the present embodiment, the vehicle speed is gradually decreased in order to stop the vehicle.

Here, it is determined whether or not the vehicle speed is equal to or lower than a predetermined vehicle speed (step S2). In this example, the predetermined vehicle speed is set at 20 km/h. That is, in step S2, the sound pressure calculating section 15 of the vehicle approaching audible system 1 determines whether or not the vehicle speed transmitted from the receiving section 11 is 20 km/h or less.

When the vehicle speed is higher than 20 km/h (No in step S2), the vehicle continues to run without being notified of the approaching sound from the vehicle approach notification device 1, and it is determined again whether the speed is 20 km/h or less. continue (step S2).

When it is determined that the vehicle speed is 20 km/s or less (Yes in step S2), the first approach sound pressure control is executed (step S3). In FIG. 4, the point at which the vehicle speed is determined to be 20 km/h or less is the boundary between the T0 region and the T1 region.

Here, the first approach sound pressure control will be described. The first approach sound pressure control sets the sound pressure based on the sound pressure map A. FIG. In step S3, the sound pressure calculation unit 15 of the approaching vehicle audible system 1 determines that the vehicle speed received from the vehicle speed detection unit 4 is 20 km/h or less, and uses the sound pressure map A stored in the sound pressure map storage unit 12 as select. Then, the sound pressure calculator 15 calculates the sound pressure for 20 km/h based on the characteristics of the line M1 in FIG. .

At this time, the sound pressure calculation unit 15 selects an approaching sound type corresponding to the sound pressure map A, and transmits information on the selected approaching sound type to the sound pressure control unit 14 . The sound pressure control unit 14 controls the speaker 2 to output an approaching sound (first approaching sound) based on the received sound pressure information and approaching sound type information.

Next, it is determined whether or not the vehicle is accelerated while the first approach sound pressure control is being executed (step S4). When the vehicle is accelerated (Yes in step S4) and the vehicle speed increases, it is determined again whether the vehicle speed is 20 km/h or less (step S2), and the above steps are repeated.

In the T1 region of FIG. 4, the brake operation is once stopped, and the accelerator (not shown) is stepped on to accelerate. At this time, the vehicle speed increases from V1 to V2. That is, in step S4, it is determined that the vehicle is being accelerated. Even while the vehicle speed is increasing from V1 to V2, the approaching vehicle audible device 1 continues to determine whether the vehicle speed is 20 km/h or less (step S2). In the example of FIG. 4, V1 and V2 are smaller than 20 km/h, so the first approach sound pressure control continues to be executed (step S3).

When the vehicle is not accelerated (No in step S4), it is determined whether the vehicle speed is equal to or less than a threshold (step S5). In this example the threshold is set at 5 km/h. When the vehicle speed is higher than 5 km/h (No in step S5), it is determined again whether the vehicle is accelerated (step S4). In the example of FIG. 4, when the vehicle speed has increased to V2, the brake operation is performed again, and the vehicle speed is reduced from V2. That is, when the vehicle speed is V2, it is determined in step S5 that the vehicle is not being accelerated (No in step S4).

When the vehicle speed is 5 km/h or less (Yes in step S5), it is determined whether or not the operation amount of the brake operation is a predetermined amount X0 or more (step S6). If the operation amount is smaller than the predetermined amount X0 (No in step S6), it is determined again whether the vehicle is to be accelerated (step S5), and the above steps are repeated.

If the manipulated variable is equal to or greater than the predetermined amount X0 (Yes in step S6), the second approach sound pressure control is started (step S7). The sound pressure map B is selected for the second approach sound pressure control. As shown in FIG. 2, the sound pressure map B has a smaller sound pressure corresponding to the vehicle speed than the sound pressure map A does. Also, an approaching sound type corresponding to the sound pressure map B is selected as the approaching sound type. The sound pressure control unit 14 controls the speaker 2 to output an approaching sound (second approaching sound) based on the received sound pressure information and approaching sound type information.

The sound pressure calculation unit 15 determines that the vehicle speed information received from the vehicle speed detection unit 4 is 5 km/h or less, and the operation amount information received from the brake operation amount detection unit 3 is a predetermined amount X0 or more (Yes in step S6). When determining that, the sound pressure calculation unit 15 selects the sound pressure map B stored in the sound pressure map storage unit 12 . It should be noted that the predetermined amount X0 of the brake operation in FIG. 4 indicates the predetermined amount of the determination criterion in step S6 of the brake operation.

Then, the sound pressure calculation unit 15 of the approaching vehicle notification device 1 calculates the sound pressure for 5 km/h based on the characteristics of M2-1 in FIG. It is transmitted to the pressure control unit 14 . At this time, the sound pressure calculation unit 15 selects an approaching sound type corresponding to the sound pressure map B, and transmits information on the selected approaching sound type to the sound pressure control unit 14 . Next, the sound pressure control unit 14 controls the speaker 2 to output the approaching sound based on the received sound pressure information and approaching sound type information. 4, the approaching vehicle audible system 1 switches from the first approaching sound pressure control to the second approaching sound pressure control, and the sound pressure of the approaching sound emitted from the speaker 2 decreases.

Further, while the second approach sound pressure control is being executed, it is determined whether or not the manipulated variable is equal to or less than the first predetermined amount X1 different from the predetermined amount X0 (step S8).

In step S8, when the operation amount is greater than the first predetermined amount X1 (No in step S8), it is determined whether or not the vehicle speed is zero (step S9). The first predetermined amount X1 is an operation amount smaller than the predetermined amount X0.

When the vehicle speed is zero in step S9 (Yes in step S9), the approaching vehicle audible device 1 stops the approaching sound (step S10), and returns to the start when the vehicle runs again (step S11). When the vehicle speed is not zero (No in step S9), the process returns to step S8 to determine whether or not the operation amount is equal to or less than the first predetermined amount X1 (step S8).

In step S8, when the operation amount is equal to or less than the first predetermined amount X1 (Yes in step S8), it is determined whether or not the vehicle is accelerated (step S8-1). When it is determined that the vehicle is being accelerated in step S8-1 (Yes in step S8-1), the process returns to step S5 to determine whether the vehicle speed is 5 km/h or less (step S5 ) and repeat the above steps.

When it is determined in step S8-1 that the vehicle is not being accelerated (No), the second approach sound pressure control is switched to the first approach sound pressure control (step S8-2). Here, it is determined whether or not the vehicle speed is zero (step S8-3).

When the vehicle speed is zero (Yes in step S8-3), the output of the approach sound based on the sound pressure map A is stopped (step S10), and the process returns to the start when the vehicle runs again (step S11). When the vehicle speed is not zero (No in step S8-3), it is determined whether or not the brake is operated (step S8-4).

When the brake operation is performed (Yes in step S8-4), the process returns to step S6 to determine whether or not the operation amount of the brake operation is equal to or greater than the predetermined amount X0 (step S6). repeat. In the example of FIG. 4, after it is determined in step S8-4 that the brake operation has been performed, the second predetermined amount X2 is used as the criterion for determining the operation amount of the brake operation. The second predetermined amount X2 in this example is larger than the first predetermined amount X1 and slightly smaller than the predetermined amount X0.

When the brake operation is not performed (No in step S8-4), the first approach sound is output at a sound pressure corresponding to 5 km/h (step S8-5), and the process returns to step S6 to brake. It is determined whether or not the operation amount of the operation is equal to or greater than the predetermined value X0 (step S6), and the above steps are repeated.

As can be seen from the above description, according to the present embodiment, either the first approach sound pressure control or the second approach sound pressure control is selected according to the brake operation in the vehicle speed range below the threshold value (5 km/h). Thus, even if the brake operation amount changes at a vehicle speed equal to or lower than the threshold, it is possible to perform control capable of outputting the approach sound with appropriate sound pressure.

When shifting (returning) from the sound pressure map B to the sound pressure map A, for example, when the vehicle speed is below the threshold value (5 km/h) and the brake is off and the vehicle is in an idle running state (creep running state) (shown at T3 in FIG. 4). area), the sound pressure of the approaching sound set by the sound pressure map A, that is, a sound pressure higher than the sound pressure set by the sound pressure map B can be output. As a result, the approach of the vehicle can be appropriately notified to the outside without the sound pressure of the approaching sound being too low.

Further, according to the present embodiment, the brake operation amount at which the map is switched (approaching sound pressure control is switched) is adjusted so that it is difficult to return from the sound pressure map B to the sound pressure map A having a relatively large sound pressure. The predetermined amount X0 and the second predetermined amount X2 are set larger than the fixed amount X1. That is, the hysteresis characteristics are set so that the condition for switching from the first approach sound pressure control to the second approach sound pressure control and the condition for switching from the second approach sound pressure control to the first approach sound pressure control are different. I have it set up. As a result, frequent switching of sound pressure maps can be suppressed. That is, it is suppressed that the sound pressure is repeatedly increased and decreased in a short period of time.

The description of the present embodiment is an example for describing the present invention, and does not limit the invention described in the claims. Moreover, the configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope described in the claims.

In the present embodiment, the sound pressure map B is set so that the sound pressure increases as the vehicle speed increases, but the present invention is not limited to this. As indicated by the line M2-2 in FIG. 2, the sound pressure may be set to be a constant sound pressure P0 that is lower than that of the sound pressure map A and regardless of whether the vehicle speed increases or decreases. Further, in the present embodiment, the first approach sound pressure control is set to the second approach sound pressure control, or vice versa, under a predetermined condition, but the present invention is not limited to this. For example, it is possible to set transition control between the first approach sound pressure control and the second approach sound pressure control so that the sound pressure changes gradually.

1 Vehicle approaching audible device 2 Speaker 3 Brake operation amount detection unit 4 Vehicle speed detection unit 11 Reception unit 12 Sound pressure map storage unit 13 Approaching sound type storage unit 14 Sound pressure control unit 15 Sound pressure calculation unit

Claims (3)

A vehicle approach notification device capable of outputting an approaching sound of a predetermined sound pressure to the surroundings of the vehicle when the vehicle speed of the vehicle drops below a predetermined vehicle speed to notify the surroundings of the vehicle of the approach of the vehicle,
first approaching sound pressure control for outputting a first approaching sound;
a second approaching sound pressure control for outputting a second approaching sound having a sound pressure different from the sound pressure of the first approaching sound,
executing the first approach sound pressure control when the vehicle speed is greater than a predetermined threshold;
configured to execute the first approach sound pressure control or the second approach sound pressure control when the vehicle speed is equal to or less than the predetermined threshold ;
When the vehicle speed is equal to or less than the predetermined threshold value and a predetermined amount of braking operation for braking the vehicle is input, the first approach sound pressure control is changed to the second approach sound pressure control. configured to
transitioning to the first approach sound pressure control when the operation amount of the braking operation for braking the vehicle reaches a first predetermined amount while the second approach sound pressure control is being executed;
When the operation amount becomes equal to or greater than a second predetermined amount larger than the first predetermined amount while the first approach sound pressure control is being executed, transition is made to the second approach sound pressure control. A vehicle approach notification device characterized by being configured as follows . the first approximant and the second approximant have a sound pressure above zero;
The sound pressure of the first approach sound output by the first approach sound pressure control is set to change according to the vehicle speed,
2. The approaching vehicle audible system according to claim 1 , wherein the sound pressure of said second approaching sound is lower than the sound pressure of said first approaching sound. When the operation amount of the braking operation for braking the vehicle becomes equal to or less than a predetermined amount while the second approach sound pressure control is being executed, the second approach sound pressure control is changed to the first approach. Transition to sound pressure control,
The sound pressure of the first approach sound output after the transition to the first approach sound pressure control is equal to the sound pressure of the second approach sound pressure control before transition to the first approach sound pressure control. 3. The approaching vehicle audible system according to claim 2 , wherein the sound pressure is higher than the set sound pressure of said second approaching sound.

Images