Loudspeaker Current Control via Predictive Modeling
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Solution Overview
Problem
Existing loudspeaker control methods are complex and introduce audible artifacts or require additional electronic components, making them costly and prone to breakdowns, as they struggle to limit current without affecting sound quality.
Innovation Solution
A control device that uses differential flatness principles to predict and adjust loudspeaker current, incorporating mechanical and electrical modeling to calculate reference currents and voltages, thereby limiting current without additional sensors or resistors, ensuring sound quality and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive electronic circuits with resistive elements are used to limit current, then current limiting is achieved, but system losses increase and device complexity increases
Solution Approach 1:
The patent replaces passive electronic resistive circuits with an active control system that uses electronic modeling and signal processing to limit current. The control device calculates a modeled current based on electrical and mechanical parameters, then adjusts the excitation signal accordingly, eliminating the need for physical resistive elements and their associated energy losses.
Solution Approach 2:
The patent creates an electrical model and mechanical model of the loudspeaker to replicate its behavior in software. By copying the loudspeaker's electrical and mechanical characteristics into computational models, the system can predict current without physical sensors and limit current through signal processing rather than physical intervention.
2Reliability
If additional electronic components are installed for current sensing and limiting, then current control is improved, but device complexity and cost increase
Solution Approach 1:
The control device uses the existing electrical parameters and mechanical parameters of the loudspeaker system to generate the modeled current. The system serves itself by utilizing available information (excitation signal, electrical parameters, mechanical parameters) to perform current limiting without requiring additional sensors or components.
Solution Approach 2:
The control device performs multiple functions: it amplifies the audio signal, models the loudspeaker's electrical and mechanical behavior, calculates the modeled current, and limits the current through signal adjustment. This multi-functional approach eliminates the need for separate current sensing and limiting circuits.
3Ease of operation
If voltage amplifier is used to supply loudspeaker, then simple voltage control is achieved, but current limiting capability is lost
Solution Approach 1:
The patent transforms the static voltage amplification function into a dynamic control system. The control device continuously calculates the modeled current based on real-time excitation signal and system parameters, then dynamically adjusts the output signal to limit current while maintaining voltage control capabilities. This dynamic approach allows the system to adapt to changing conditions.
Data Source
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AI summary
The invention relates to a device for controlling a loudspeaker (14) in an enclosure, comprising: an inlet for an audio signal to be reproduced; an outlet for supplying an excitation signal of the loudspeaker; and means (26, 36, 38, 70, 71, 80, 90) for calculating, at all times (t), at least one predicted current (iref(t)) for the excitation signal of the loudspeaker (14) according to the audio signal. It comprises an attenuator (71) for limiting the predicted current to a limited current value lower than a threshold value by applying, to the predicted current, an attenuation gain which is a function of the predicted current.