Bearing Load Estimation Using Strain Harmonics and Contact Angle Compensation
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Solution Overview
Problem
Existing methods for estimating bearing loads are inaccurate due to variations in rolling element contact angles, which affect the transfer function of strain signals and lead to estimation uncertainties.
Innovation Solution
A load estimating method that uses harmonic components of strain signals to calculate bearing loads as a polynomial function, incorporating contact angle parameters to account for angle variations, and employs multiple strain sensor probes to improve accuracy by sampling in the spatial domain and rejecting low-order bending modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional strain-based methods are used to estimate bearing load, then the measurement process is simple, but the measurement precision deteriorates due to contact angle variation errors
Solution Approach 1:
The method performs preliminary action by extracting shape information and calculating harmonic components from the strain signal before final load reconstruction. This preprocessing step separates the contact angle variation effects from the load magnitude, allowing for more accurate subsequent load estimation by accounting for angular variations in advance.
Solution Approach 2:
The invention changes parameters by transforming the strain signal into harmonic components (frequency domain parameters) and using the ratio of harmonic powers as a new parameter that represents contact angle variation. This parameter transformation enables the system to separately identify and compensate for angular variation effects, improving measurement precision.
2Measurement precision
If multiple strain sensor probes are used to sample in spatial domain, then the measurement precision improves by rejecting bending modes, but the device complexity increases
Solution Approach 1:
The method applies segmentation by dividing the bearing structure into multiple sensor locations and processing the strain signals from each probe separately. By segmenting the measurement locations and analyzing harmonic components at each position, the system can identify and reject bending modes that affect all sensors uniformly, thereby improving load reconstruction accuracy.
Solution Approach 2:
The harmonic components serve as an intermediary that mediates between the raw strain signals from multiple probes and the final load reconstruction. By introducing harmonic analysis as an intermediate processing step, the system can extract meaningful load information while filtering out unwanted bending vibrations that contaminate the direct strain measurements.
Data Source
AI summary
A method for estimating a bearing load in a bearing having a first ring, a second ring and a row of rolling elements arranged between the first ring and the second ring, the method including: equipping the first ring with at least one strain sensor probe, transmitting a strain signal waveform from the at least one strain sensor probe to an electronic control unit, extracting shape information of the waveform of the strain signal using a first harmonic component (u) and a second harmonic component (v) of the strain signal, and calculating a bearing load estimation as a polynomial function of the first and second harmonic components (u, v) of the strain signal.