Gear Defect Detection Using Dynamic Thresholds for Acceleration States
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gear defect detection technologies are inadequate for detecting defects in typical gears with teeth evenly spaced on the entire outer circumference, especially during acceleration or deceleration.
Innovation Solution
A gear defect detection device that utilizes a sensor to obtain a pulse signal representing the top and bottom portions of the gear, and a calculation unit to determine the presence of defects based on the ratio of signal section lengths and additional factors such as acceleration and jerk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gear is rotated at a constant speed to enable defect detection by signal ratio comparison, then the signal has a 1:1 ratio between top and bottom portions enabling defect detection, but the gear cannot operate during acceleration or deceleration which are normal operational states
Solution Approach 1:
The patent applies dynamics by making the determination threshold variable rather than fixed. The threshold is dynamically adjusted based on the gear's acceleration state, allowing the system to adapt to changing operational conditions. This resolves the contradiction by enabling accurate defect detection during both constant speed and acceleration/deceleration states through adaptive threshold modification.
Solution Approach 2:
The patent changes the parameter of the determination threshold based on acceleration information. By modifying the threshold parameter according to the gear's acceleration state, the system maintains defect detection accuracy across varying operational conditions, thus resolving the contradiction between constant speed requirement and acceleration/deceleration adaptability.
2Measurement precision
If the conventional technology uses a specific crank rotor gear configuration with teeth only in certain portions, then lost tooth detection can be performed, but defects in typical gears with teeth evenly spaced on the entire outer circumference remain undetectable
Solution Approach 1:
The patent achieves universality by developing a defect detection method that works for both specific crank rotor gears and typical gears with evenly spaced teeth. The method uses acceleration information and dynamic threshold adjustment to detect defects in any gear configuration, making the system multi-functional and broadly applicable across different gear types.
Solution Approach 2:
The patent applies dynamics by using acceleration information to dynamically adjust the determination threshold, enabling the system to detect defects in various gear configurations including typical gears with evenly spaced teeth, not just specific crank rotor gears.
3Device complexity
If the determination threshold is fixed for defect detection, then the detection method is simple to implement, but detection accuracy deteriorates during acceleration or deceleration when the signal ratio deviates from 1:1
Solution Approach 1:
The patent changes the determination threshold parameter based on acceleration state, transforming it from a fixed value to a variable threshold. This resolves the contradiction by maintaining detection simplicity through automated threshold adjustment while improving accuracy during acceleration and deceleration operations.
Solution Approach 2:
The patent implements feedback by using acceleration information to continuously adjust the determination threshold. This feedback mechanism maintains optimal detection accuracy across varying operational conditions without significantly increasing system complexity, as the threshold adjustment is automatically performed based on measured acceleration.
Data Source
AI summary
A gear defect detection device includes an acquisition unit that obtains a pulse signal from a sensor, where the pulse signal includes first signal sections and second signal sections alternating one after another, the first signal sections each represent a bottom portion of the gear, and the second signal sections each represent a top portion of the gear; and a calculation unit that determines, presence or absence of a defect of the gear on a basis of a ratio between the length of a first time period of a corresponding one of the first signal sections and the length of a second time period of a corresponding one of the second signal sections, and further determines the presence or absence of a defect of the gear using at least one of acceleration or jerk of an object that acts according to rotation of the gear.