Rotary Device Load Detection Using Phase-Difference Sensor Signals
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Solution Overview
Problem
Existing rotary devices with sensors face challenges in accurately detecting load on rotary members due to manufacturing errors causing whirling motions, which result in periodic fluctuations in sensor output signals, necessitating correction to isolate actual load from unnecessary components.
Innovation Solution
A rotary device with a sensor system where the sensor functions both as a displacement sensor and a rotary sensor, using a sensor rotor that rotates with the rotary member, outputs phase-different waveform signals to calculate rotation angles and displacement, allowing for load calculation by processing these signals, and optionally uses stored correction data to reduce whirling effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a displacement sensor is used to detect load on the hub shaft, then the load can be calculated from the sensor output, but manufacturing errors cause whirling motion that appears as periodic fluctuations in the sensor output, reducing measurement precision
Solution Approach 1:
The sensor output signal is segmented into two components: periodic fluctuations caused by whirling motion and actual load-induced displacement. By separating these components through spectral analysis or filtering, the actual load signal can be extracted with higher precision, resolving the contradiction between measurement precision and reliability
Solution Approach 2:
The system uses the detected periodic fluctuations as feedback to identify and compensate for whirling motion effects. By continuously monitoring the sensor output and adjusting the load calculation based on the identified whirling component, the system maintains reliable and precise measurements despite manufacturing errors
2Measurement precision
If a second rotary sensor is added to correct the sensor output for whirling motion, then measurement precision improves, but device complexity and quantity of components increase
Solution Approach 1:
The existing displacement sensor is made multi-functional by using it to detect both the periodic fluctuations from whirling motion and the actual load-induced displacement. Through signal processing, a single sensor performs the work of what would traditionally require multiple sensors, improving precision without increasing device complexity
Solution Approach 2:
The sensor system serves itself by using its own output signal to detect and correct for whirling motion effects. The periodic fluctuations in the sensor output provide self-diagnostic information that enables the system to compensate for its own errors, eliminating the need for additional correction sensors
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
This solution enables accurate calculation of displacement and load on rotary members by eliminating the need for separate sensors, reducing device size and weight, and improving calculation accuracy by using phase-different signals and correction data to correct for whirling motions.
Implementation Method 1
The first sensor is configured to output a waveform signal that is delayed in phase when the rotary member is displaced relative to the stationary member. The second sensor is configured to output a waveform signal that is advanced in phase when the rotary member is displaced relative to the stationary member. The processing device is configured to calculate, based on the waveform signals, a first rotation angle of the sensor rotor at a first detection target position for the first sensor and a second rotation angle of the sensor rotor at a second detection target position for the second sensor.
Data Source
AI summary
A rotary device includes a stationary member, a rotary member, a sensor device including a sensor rotor, a first sensor, and a second sensor, and a processing device. The first sensor is configured to output a waveform signal that is delayed in phase when the rotary member is displaced relative to the stationary member. The second sensor is configured to output a waveform signal that is advanced in phase when the rotary member is displaced relative to the stationary member. The processing device is configured to calculate a displacement of the sensor rotor based on a difference between a first rotation angle and a second rotation angle, to correct the calculated displacement, and to calculate a load acting on the rotary device from the corrected displacement.