Elastic Panel Modal Control With Common-Source Actuators
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Solution Overview
Problem
Existing control systems for structures using force actuators to excite or depress vibrational resonant modes are complex and costly due to the need for additional electronics to implement weighting functions for precise signal control, leading to increased manufacturing costs and reduced reliability.
Innovation Solution
A system comprising a panel with dynamic force actuators positioned to significantly actuate a selected mode while minimizing excitation of other modes, using a common signal source and a modal crossover network to ensure equal force application across actuators, thereby simplifying the control of sound radiation and reducing unwanted distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If weighting functions are implemented using additional electronics to control signal amplitudes for each actuator, then selective modal control precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the weighting function implementation from complex electronic signal processing and relocates it to the mechanical domain through strategic actuator placement. By positioning actuators at specific locations on the panel (such as antinodal points), the desired modal weighting is achieved passively through the structure's natural vibration patterns, eliminating the need for additional electronics while maintaining control precision
Solution Approach 2:
The panel structure itself serves the dual function of both the vibrational element and the positioning reference for actuators. The natural mode shapes and nodal/antinodal patterns of the panel provide the weighting information needed for selective modal control, making the system self-configuring without external intervention or complex control electronics
2Measurement precision
If weighting functions are implemented using additional electronics to control signal amplitudes for each actuator, then selective modal control precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the expensive electronic weighting function implementation and replaces it with a mechanical solution based on actuator positioning. The weighting is achieved through the physical locations of actuators relative to the panel's modal patterns, eliminating the need for additional amplifiers, signal processors, and associated electronics, thereby significantly reducing manufacturing cost
Solution Approach 2:
The patent uses simple, low-cost actuator mounting positions that can be determined through basic modal analysis rather than requiring precision electronic control systems. The solution relies on inexpensive mechanical placement rather than expensive electronic components, making the system more cost-effective for manufacturing
3Measurement precision
If weighting functions are implemented using additional electronics to control signal amplitudes for each actuator, then selective modal control precision is improved, but system reliability decreases
Solution Approach 1:
The patent extracts the weighting function from the electronic control system and implements it through the mechanical positioning of actuators. This removes multiple electronic components (amplifiers, signal processors, weighting networks) that could fail, thereby improving system reliability while maintaining the ability to achieve selective modal control through strategic actuator placement at antinodal and nodal positions
Solution Approach 2:
The patent combines the functions of structural vibration and control signal weighting into a single integrated system. The panel's natural mode shapes provide both the vibrational response and the weighting information, merging what were previously separate functions (structure and control electronics) into one unified system that is inherently more reliable
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
The system effectively radiates sound in a selected frequency band with minimal excitation of unwanted modes, reducing manufacturing costs and improving reliability by optimizing actuator placement and using a common signal source, resulting in clear and distortion-free sound output.
Implementation Method 1
the dynamic force actuators are positioned in an array at locations on the panel that are determined to significantly actuate a selected panel mode in a given frequency range while minimizing the excitation of all other modes
Implementation Method 2
Force actuators have been employed for a number of years to excite/depress the response of one or more vibrational resonant modes in structures
Data Source
AI summary
A method, system and devices to selectively control modal vibrations in an elastic panel with a number of force actuators distributed throughout the surface of the elastic panel to excite/depress the response of one or more vibrational resonant modes included in a prescribed subset. The force actuators are disposed such that prescribed modal excitation/depression may be realized when the actuators are driven by a common source signal.