Notification device and notification method
Provided is a notification device and notification method that reduce the output and power consumption of an amplifier or the like and allow a user to sufficiently feel the presence or absence of notification through vibration. A notification device ( 1 ) includes a sweep signal generator ( 4 ) configured to generate a detection sweep signal by continuously changing the frequency in a frequency band in which a speaker ( 6 ) can cause a user to feel a signal in the form of vibration, a vibration detector ( 7 ) configured to detect vibration outputted from the speaker ( 6 ), and a sound measurement unit ( 8 ) configured to detect, as a sweep frequency band, a frequency band in which vibration indicates signal levels equal to or higher than a threshold. The sweep signal generator ( 4 ) generates a resonance sweep signal by changing the frequency in the sweep frequency band and causes the speaker ( 6 ) to generate vibration.
1. A notification device comprising:
a speaker installed in a seat;
a sweep signal generator configured to generate a detection sweep signal that continuously changes a frequency of vibration that the speaker outputs for a user, by changing a frequency of a predetermined wave at a constant speed in a frequency band in which the user can be notified by the vibration;
a vibration detector configured to detect vibration of a seat surface caused by acoustic sound output by the speaker using the detection sweep signal generated by the sweep signal generator; and
a sound measurement unit configured to determine a frequency band indicating a signal level equal to or higher than a predetermined threshold as a sweep frequency band in frequency characteristics of the vibration detected by the vibration detector, wherein
the sweep signal generator sets a variation margin for the sweep frequency band determined by the sound measurement unit, the sweep signal generator generates a resonance sweep signal by changing the frequency of the predetermined wave at a constant speed in the sweep frequency band and in the variation margin,
the speaker generates vibration in the seat using the resonance sweep signal, and
the sweep signal generator changes a state of vibration generated by the speaker by setting at least one of an upper-limit frequency and a lower-limit frequency of the resonance sweep signal obtained by changing the frequency of the predetermined wave, to a frequency different from an upper-limit frequency and a lower-limit frequency of the sweep frequency band determined by the sound measurement unit by adding the variation margin to at least one of the upper-limit frequency and the lower-limit frequency of the sweep frequency band determined by the sound measurement unit.
2. The notification device according to claim 1 ,
wherein the sweep signal generator changes a cycle of vibration generated by the speaker by changing a speed at which the frequency of the predetermined wave of the resonance sweep signal is changed.
3. The notification device according to claim 1 ,
wherein the sound measurement unit determines, as a resonant frequency, a frequency value indicating a high signal level in the frequency characteristics of the vibration detected by the vibration detector, and
the sweep signal generator changes, to the resonant frequency, at least one of the upper-limit frequency and the lower-limit frequency of the resonance sweep signal obtained by changing the frequency of the predetermined wave.
4. A notification method using a notification device comprising:
a detection sweep signal generation step of generating, by a sweep signal generator, a detection sweep signal that continuously changes a frequency of vibration that a speaker installed in a seat outputs for a user, by changing a frequency of a predetermined wave at a constant speed in a frequency band in which the user can be notified by the vibration;
a vibration detection step of detecting, by a vibration detector, vibration of a seat surface caused by acoustic sound output by the speaker using the detection sweep signal generated in the detection sweep signal generation step;
a sound measurement step of determining, by a sound measurement unit, a frequency band indicating a signal level equal to or higher than a predetermined threshold as a sweep frequency band in frequency characteristics of the vibration detected in the vibration detection step; and
a resonance sweep signal generation step of generating, by the sweep signal generator, a resonance sweep signal by setting a variation margin for the sweep frequency band determined by the sound measurement unit and changing the frequency of the predetermined wave at a constant speed in the sweep frequency band and in the variation margin, wherein
the speaker generates vibration in the seat using the resonance sweep signal, and
the resonance sweep signal generation step comprises the sweep signal generator changing a state of vibration generated by the speaker by setting at least one of an upper-limit frequency and a lower-limit frequency of the resonance sweep signal obtained by changing the frequency of the predetermined wave, to a frequency different from an upper-limit frequency and a lower-limit frequency of the sweep frequency band determined in the sound measurement step by adding the variation margin to at least one of the upper-limit frequency and the lower-limit frequency of the sweep frequency band determined by the sound measurement step.
5. The notification method using the notification device according to claim 4 ,
wherein the resonance sweep signal generation step comprises the sweep signal generator changing a cycle of vibration generated by the speaker by changing a speed at which the frequency of the predetermined wave of the resonance sweep signal is changed.
6. The notification method using the notification device according to claim 4 , wherein
the sound measurement step comprises the sound measurement unit determining, as a resonant frequency, a frequency value indicating a high signal level in the frequency characteristics of the vibration detected in the vibration detection step, and
the resonance sweep signal generation step comprises the sweep signal generator changing, to the resonant frequency, at least one of the upper-limit frequency and the lower-limit frequency of the resonance sweep signal obtained by changing the frequency of the predetermined wave.