Parametric Speaker Ultrasonic Warning System for Targeted Alerts
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Solution Overview
Problem
Existing sound generating systems and ultrasound emitting apparatuses often produce audible warnings in fixed areas or call attention to individuals who do not need it, such as pedestrians on sidewalks when a target person is on a crosswalk, due to their directional limitations.
Innovation Solution
A sound generating system and method utilizing a parametric speaker principle with frequency shift between two ultrasound waves, where a first ultrasound emitting apparatus on a moving object and a second fixed apparatus generate overlapping ultrasound waves, allowing audible signals to be modulated and heard only when the moving object approaches a specific area, thereby providing targeted warnings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a warning sound generating apparatus emits ultrasound waves from two fixed generators on street sides, then an audible sound is generated in a fixed overlapping area, but a pedestrian always hears the audible sound even when there is no vehicle, causing unnecessary warnings
Solution Approach 1:
The patent applies dynamics by making the ultrasound emitting apparatus mounted on a moving object (vehicle) instead of being fixed. The apparatus dynamically moves with the vehicle, allowing the audible sound to be generated only in the specific area where the vehicle is present and the ultrasound waves overlap with the fixed generator's waves. This resolves the contradiction by ensuring warnings are activated only when actually needed (vehicle present) while maintaining reliable detection in the target area.
2Ease of operation
If an attention calling apparatus emits ultrasound waves from a moving object to call attention of a target person, then the target person can hear the warning, but even persons who do not need attention (e.g., pedestrians on sidewalk with guardrail) hear the audible sound
Solution Approach 1:
The patent applies local quality by creating a localized audible sound area through the overlap of ultrasound waves from the moving apparatus and the fixed generator. The audible sound is generated only in the specific overlapping region, allowing precise targeting of warnings to pedestrians in the crosswalk area while avoiding disturbance to non-target persons on sidewalks with guardrails or in other areas where the ultrasound waves do not overlap.
3Loss of information
If ultrasound waves are emitted to generate audible sound through parametric speaker principle, then targeted sound generation is achieved, but the system complexity increases due to requiring multiple ultrasound generators and coordination
Solution Approach 1:
The patent applies the intermediary principle by using the fixed ultrasound generator as a mediator that provides the stationary ultrasound wave component. The moving apparatus only needs to provide the modulated ultrasound wave, simplifying its design while still achieving the parametric speaker effect through the interaction between the two generators. This reduces the complexity of the moving apparatus while maintaining the spatial targeting capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures that a target person in a predetermined area receives a sound alarm only when a moving object is close, reducing unnecessary warnings and improving the effectiveness of attention calling systems.
Implementation Method 1
A principle of generating the audible sound is based especially on a 'principle of a parametric speaker with reference to a frequency shift between two types of ultrasound waves.'
Implementation Method 2
The principle of generating this audible sound is based especially on a 'principle of a parametric speaker with reference to nonlinear characteristics when an ultrasound wave propagates through the air.'
Data Source
AI summary
Disclosed are a sound generation system, an ultrasonic wave emitting device, and an ultrasonic wave emitting method which utilize the principle of parametric speakers (which uses the difference between frequencies of two ultrasonic waves) and which are capable of allowing target persons in a prescribed area to hear a sound only when a mobile body approaches said prescribed area. An alert system (10) has an ultrasonic wave emitting device (100) mounted on a mobile body (200), and an ultrasonic wave emitting device (300) permanently installed near an area (A101). The ultrasonic wave emitting device (300) emits a first ultrasonic wave towards an area at least including the aforementioned area (A101), and meanwhile, the ultrasonic wave emitting device (100) emits a second ultrasonic wave. The ultrasonic emitting device (100) forms the second ultrasonic wave by means of modulating the ultrasonic wave of frequency f1 with an audible signal.