Cutting Tool Sensor Sampling for Low-Frequency Abnormality Detection
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Solution Overview
Problem
Existing systems for generating digital signals from analog signals output by sensors attached to cutting tools are inefficient, particularly in determining optimal sampling frequencies and process periods to accurately detect abnormalities during cutting processes.
Innovation Solution
A processing system that includes a cutting tool, a sensor, an AD converter, and a processing unit configured to determine a sampling frequency and process period based on the rotation rate and upper-limit pitch, ensuring the angle pitch is within a set limit, allowing for efficient generation of digital signals at multiple measuring points even with low sampling frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sampling frequency is reduced to lower data processing load, then energy consumption and device complexity decrease, but measurement precision and abnormality detection capability deteriorate
Solution Approach 1:
The patent segments the rotation cycle into multiple measurement points and uses multiple sensors positioned at different angular positions around the rotor. This segmentation allows the system to capture comprehensive vibration data across the entire rotation cycle even at lower sampling frequencies, maintaining measurement precision while reducing overall data processing requirements.
Solution Approach 2:
The patent transitions from temporal sampling alone to a combination of spatial distribution (multiple angular positions) and temporal sampling. By adding the spatial dimension with multiple sensors arranged circumferentially, the system achieves comprehensive measurement coverage without requiring high sampling frequencies, thus resolving the contradiction between sampling rate and detection precision.
2Measurement precision
If sampling frequency is increased to capture more measuring points, then measurement precision improves, but energy consumption and data processing load increase
Solution Approach 1:
The system divides the measurement task across multiple sensors positioned at different angular positions, with each sensor capturing data at moderate sampling rates. This segmentation distributes the measurement burden, achieving comprehensive precision without requiring any single sensor to operate at high energy-consuming sampling rates.
Solution Approach 2:
The patent merges data from multiple sensors positioned at different angular positions to create a complete picture of rotor vibration characteristics. By combining measurements from multiple low-to-moderate sampling rate sensors, the system achieves the equivalent precision of a single high sampling rate sensor while consuming less energy.
3Loss of time
If process period is shortened to enable earlier abnormality detection, then responsiveness improves, but sampling frequency requirements increase leading to higher energy consumption
Solution Approach 1:
The patent segments the rotation cycle into multiple angular positions with sensors distributed around the rotor. This spatial segmentation allows the system to detect abnormalities at any angular position without requiring continuous high-frequency temporal sampling, enabling short effective detection periods with moderate sampling rates and lower energy consumption.
Solution Approach 2:
The continuously rotating rotor with circumferentially distributed sensors provides continuous measurement coverage throughout the rotation cycle. This continuous spatial coverage ensures that abnormalities can be detected at any point in the rotation without requiring high sampling frequencies, maintaining rapid detection capability while reducing energy consumption.
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 configuration enables more efficient generation of digital signals, allowing for early detection of abnormalities and accurate analysis of cutting tool states by ensuring a larger number of measuring points are captured within a rotation cycle, even with lower sampling frequencies.
Implementation Method 1
an analog-to-digital (AD) converter configured to perform sampling on an analog signal output from the sensor to generate a digital signal
Data Source
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AI summary
A processing system includes a cutting tool, a sensor attached to the cutting tool, an analog-to-digital (AD) converter configured to perform sampling on an analog signal output from the sensor to generate a digital signal, and a processing unit. The processing unit is configured to, based on a rotation rate [rpm] of a rotor that rotates about a rotation axis; an upper-limit period that is an upper-limit value of a process period that is a period with which a predetermined process is performed using the digital signal generated by the AD converter; and an upper-limit pitch that is an upper-limit value of an angle pitch [degree] that is a rotation angle between two adjacent sampling time points in a coordinate system representing a phase at a time point of sampling performed by the AD converter in a rotation circle that is a path of a point that rotates about the rotation axis as the rotor rotates, determine the process period and a sampling frequency with which the AD converter performs sampling such that a set value of the angle pitch is equal to the upper-limit pitch or less in a time period taken by the rotor to rotate N times with the process period that is equal to the upper-limit period or shorter, wherein N and (360/ps) are integers of 2 or greater and are relatively prime, where ps denotes the set value.