Actuator Fault Detection from Piston Travel Time and Stroke
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting abnormalities in actuators, such as faults, are cumbersome and difficult to set up due to variations in fluid conditions, pressure, and travel rates, making them inefficient and costly.
Innovation Solution
An abnormality detecting system that uses first and second sensors to measure the travel time and total travel distance of a movable portion between the ends of an actuator, with an external input unit for stroke data and an abnormality detecting unit that analyzes these parameters to quickly and accurately identify actuator issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If abnormality detection is performed based on pressurized fluid leakage using a flow sensor, then abnormality detection capability is provided, but detection accuracy deteriorates due to variations in tube conditions, pressure values, pulsation, and temperature
Solution Approach 1:
The invention extracts the detection target from fluid leakage measurements to movable portion travel time measurements. By using sensors that detect the position of the movable portion at the ends of its stroke, the system eliminates dependence on fluid conditions (pressure, temperature, pulsation) and tube characteristics, thereby resolving the contradiction between providing abnormality detection capability and maintaining detection accuracy under varying conditions.
Solution Approach 2:
The invention replaces the fluid-based detection system (flow sensors measuring pressurized fluid leakage) with a mechanical position-based detection system (sensors detecting movable portion position). This substitution eliminates the influence of fluid dynamics variables and directly measures the physical movement of the actuator, achieving accurate abnormality detection independent of fluid conditions.
2Reliability
If abnormality detection is performed based on lowest working pressure using a pressure sensor, then abnormality detection capability is provided, but ease of operation deteriorates due to requirements for checking at rest and adjusting for actuator specifications
Solution Approach 1:
The system performs automatic abnormality detection by continuously monitoring movable portion position and comparing travel time against pre-stored reference values. The abnormality detecting device autonomously determines abnormalities without requiring operator intervention to check conditions at rest or adjust settings based on actuator specifications, thereby improving ease of operation while maintaining detection reliability.
Solution Approach 2:
The invention stores reference travel time values in advance during setup or calibration phases. During normal operation, the system simply compares real-time measurements against these pre-established references, eliminating the need for operators to perform complex checks or adjustments based on actuator bore size and stroke, thus simplifying operation while maintaining accurate detection.
3Reliability
If statistical data-based takt time detection is used as in prior art, then abnormality detection is provided, but device complexity increases due to requirements for determining individual device settings and thresholds
Solution Approach 1:
The invention creates a universal abnormality detection system that uses standardized reference travel time values applicable across different actuator types. By storing reference values in advance and using a统一的 comparison methodology, the system eliminates the need for complex individual device settings and threshold determinations, reducing device complexity while maintaining broad applicability and detection reliability.
Data Source
AI summary
An abnormality detecting system and an abnormality detecting method acquires a stroke of a piston as input from outside, calculates a travel time of the piston based on the results of sensing obtained by a first sensor and a second sensor, calculates a total travel distance of the piston using the number of operations and the stroke of the piston, and detects an abnormality of the actuator based on the travel time and the number of operations or the total travel distance of the piston.