Directional Speaker Systems for Restricted-Area Passenger Audio
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Solution Overview
Problem
Existing passenger conveyance systems struggle to deliver targeted audio communications to specific users without disturbing others, particularly in crowded environments, and often rely on visual displays that can be missed or require multiple systems for personalized messaging.
Innovation Solution
A directional speaker system that uses phased array or parametric ultrasound technology to transmit audio communications to specific, restricted target areas, combined with a passenger detection system to identify and track users, ensuring personalized and non-intrusive messaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a broadcast public address system is used to communicate with all users, then all users can receive all messages, but other users are disturbed or distracted by messages not relevant to them
Solution Approach 1:
The patent applies local quality by directing audio communications to specific localized areas within the passenger conveyance system rather than broadcasting uniformly to all spaces. The directional speaker system creates zone-specific audio fields that deliver messages only to intended recipients in particular locations, eliminating unnecessary exposure to irrelevant communications while maintaining complete message delivery to target users.
2Loss of information
If visual displays are used to convey user-specific messages, then messages can be targeted to specific users, but users may miss the message if they do not pay attention to the display
Solution Approach 1:
The patent employs audio communication as an intermediary medium to deliver targeted messages to users. Instead of relying on visual displays that require user attention, the system uses directional audio transmission to convey information directly to users' auditory senses. This intermediary approach maintains message targeting accuracy while significantly improving reception reliability, as audio messages are harder to miss than visual displays in crowded environments.
3Ease of operation
If phased array speaker systems are used for directional sound transmission, then sound can be directed in specific directions, but the system dimensions become moderately large
Solution Approach 1:
The patent applies parameter changes by transitioning from audible frequency phased array systems to ultrasonic frequency parametric array systems. This parameter change in operating frequency enables much tighter beam formation and directional control with a significantly reduced speaker array footprint. The ultrasonic carrier waves allow the system to achieve the same directional control function with much smaller physical dimensions while maintaining ease of directional operation.
4Area of stationary object
If parametric array ultrasonic transducers are used for directional sound transmission, then a focused narrow beam can be delivered from a small sized speaker array, but the system requires nonlinear interactions to generate audible sound
Solution Approach 1:
The patent applies the blessing in disguise principle by utilizing the nonlinear acoustic interactions that occur in air as a beneficial mechanism rather than treating them as unwanted distortion. The ultrasonic carrier waves and modulated signal intentionally interact through nonlinear air properties to generate difference frequencies in the audible range. This converts what would normally be considered acoustic distortion into the desired audible output, enabling small-sized arrays to produce focused directional sound without requiring complex additional signal generation hardware.
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
Enables targeted audio communications to specific users, reducing distractions and enhancing user experience by personalizing messages based on user location and identity, while maintaining privacy and safety in crowded environments.
Implementation Method 1
In some examples, phased array speaker systems can be used in which sound is transmitted from several individual speaker elements of the array with a selected delay between those elements such that the sound constructively interferes in a desired beam direction but is attenuated outside of that beam direction.
Implementation Method 2
In other examples, modulated ultrasound can be used for directional sound transmission. For example, a parametric array of ultrasonic transducers can be used to generate a carrier wave signal and a modulated signal. The much higher frequency of such ultrasound waves allows them to be far more directional so that a focused and narrow beam of sound can be delivered from a relatively small sized speaker array.
Implementation Method 3
sound is transmitted from several individual speaker elements of the array with a selected delay between those elements such that the sound constructively interferes in a desired beam direction
Implementation Method 4
By making use of nonlinear interactions, the two transmitted waves can interfere to generate sound in the human auditory range.
Data Source
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AI summary
A passenger conveyance system (100; 200; 300; 400; 500; 600) comprising: a directional speaker system (106; 206; 306; 406a-c; 506a-b; 606) configured to transmit an audio communication (120a-b; 220a-b; 320a-b; 420a-e) into a restricted target area (110a-b; 310a-b; 410a-b; 610a-c). Using a directional speaker system allows audio communications to be sent to a user (or to multiple users) without broadcasting the message more widely. Thus other users of the system are not disturbed or distracted by messages that are not of interest to them or not relevant to them.