Rotational Frequency Estimation via Vibration Weighting
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Solution Overview
Problem
Existing mechanical systems with rotating members face challenges in measuring rotational frequencies due to increased complexity, weight, and cost associated with electro-mechanical sensors, as well as environmental limitations such as high temperatures and harsh conditions that prevent the use of these sensors.
Innovation Solution
A system using an accelerometer and processors to generate a frequency spectrum weighting function, allowing for the estimation of rotational frequencies based on remotely sensed vibrations, which involves calculating and applying a weighting function to amplify the vibrational frequencies associated with the rotating member while minimizing noise, using supervised learning techniques and optimization models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tachometers or rotation sensors are used to measure rotational frequency, then measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces electro-mechanical sensors (tachometers) with a computational approach using accelerometers and signal processing algorithms. The rotational frequency is determined by analyzing vibration signals through frequency spectrum analysis and applying weighting functions, substituting direct mechanical measurement with an indirect computational method that reduces system complexity while maintaining measurement capability
Solution Approach 2:
The patent introduces vibration signals as an intermediary to indirectly measure rotational frequency. Instead of directly measuring rotation with a tachometer, the system measures vibrations generated by the rotating member and uses frequency spectrum analysis to derive the rotational frequency from these intermediary vibration measurements
2Measurement precision
If tachometers are installed on rotating members, then rotational frequency measurement is achieved, but weight increases
Solution Approach 1:
The patent substitutes heavy electro-mechanical tachometers with lightweight accelerometers and computational processing. The measurement function is transferred from a dedicated mechanical sensor to a combination of vibration sensing and digital signal processing, significantly reducing the weight added to the rotating member while achieving the same measurement objective
3Measurement precision
If rotation sensors are added to mechanical systems, then rotational frequency can be measured, but installation complexity and retrofitting requirements increase
Solution Approach 1:
The patent uses vibration signals as an intermediary that can be captured from existing mechanical structures without modification. Accelerometers can be mounted on stationary components near the rotating member, utilizing the structure's natural vibration transmission, thereby avoiding complex installation on rotating parts and eliminating retrofitting requirements
Solution Approach 2:
The patent creates a measurement system that can be applied universally to different rotating members by using accelerometers mounted on common structural components. The vibration-based measurement approach works across various mechanical configurations without requiring sensor installation on each specific rotating member, simplifying both initial manufacturing and retrofitting applications
4Measurement precision
If electro-mechanical sensors are used in high temperature environments, then rotational frequency can be measured, but sensor reliability decreases due to environmental constraints
Solution Approach 1:
The patent uses vibration signals as an intermediary measurement approach that allows the sensing element (accelerometer) to be positioned in a thermally favorable location away from the high-temperature rotating member. The vibration transmission through mechanical coupling enables remote measurement, placing the sensitive electronics in a cooler environment while still capturing rotational frequency information
Solution Approach 2:
The patent separates the sensing function from the measurement processing function. The accelerometer captures vibration signals in a relatively cool environment, while the frequency spectrum analysis and rotational frequency determination are performed computationally, allowing the electronic components to operate outside the harsh high-temperature zone while maintaining measurement capability
Data Source
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AI summary
Apparatus and associated methods relate to generating a frequency spectrum weighting function for use in estimating a rotational frequency of the rotating member. The estimation of the rotational frequency is based on vibrations sensed by an accelerometer remotely located from a rotating member. The frequency spectrum weighting function is generated by a supervised learning method. The method includes receiving a set of test vectors. The test vectors include a rotational frequency value of the rotating member and a vibrational frequency spectrum corresponding to vibrations propagated to the accelerometer. The vibrations include vibrations caused by the rotating member rotating at the rotational frequency. The method includes calculating a test weighting function, and then weighting the vibrational frequency spectra by the test weighting function. The method includes calculating a vector score indicative of whether the weighted vibrational frequency spectra promote the identification of the rotational frequency of the rotating member. The score relates the amplitude of the weighted vibrational frequency spectrum corresponding to the rotational frequency or speed of the rotating member to the maximum amplitude of the weighted vibrational frequency spectrum corresponding to frequencies not corresponding to the frequency of the rotating member.