Rotary Machine Control Device Abnormality Detection
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Solution Overview
Problem
Existing control devices for rotary machines face challenges in detecting abnormalities, particularly when the machine is stopped or operating with increasing torque, leading to false detections and increased costs due to redundant systems.
Innovation Solution
A control device that includes a power feed unit, rotation-state detecting unit, torque detecting unit, and an abnormality determining unit, which generates an excitation command to oscillate the rotary machine, allowing for abnormality detection based on the responses of these units, thereby extending the abnormality detectable operating state and improving accuracy while reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If abnormality detection is performed based on basic control response without application of detection signal, then the system complexity is reduced, but the abnormality detection capability is insufficient during rotation stop or torque increase states
Solution Approach 1:
The system applies an excitation command to generate a known response signal before performing abnormality detection. This preliminary action creates a detectable response that allows the system to assess sensor functionality actively, rather than passively relying on basic control responses that may not generate sufficient signal during certain operating states.
Solution Approach 2:
The excitation command is applied periodically or at specific intervals to generate response signals for abnormality detection. This periodic excitation ensures that detection opportunities occur regularly, allowing the system to monitor sensor health continuously across different operating conditions without requiring complex real-time analysis.
2Speed
If instantaneous motor torque is applied for abnormality detection, then the detection speed is improved, but false detection occurs when friction changes with load state
Solution Approach 1:
The system uses feedback from both the rotation state sensor and torque sensor to determine abnormality. By comparing the actual response against the excitation command and cross-validating between multiple sensors, the system can distinguish between normal friction variations and actual sensor abnormalities, reducing false detections while maintaining fast detection speed.
Solution Approach 2:
The excitation command serves as an intermediary signal that mediates between the control system and the sensors. This known input signal allows the system to isolate sensor responses from load-dependent friction effects, enabling accurate abnormality detection regardless of varying operating conditions.
3Measurement precision
If two systems are used for each sensor to detect abnormality through mutual comparison, then the abnormality detection accuracy is improved, but the apparatus cost is doubled
Solution Approach 1:
The excitation command mechanism serves multiple functions: it generates a known response signal for sensor testing, provides an additional control input for normal operation, and enables cross-validation between sensors. This multi-functionality allows the system to achieve high detection accuracy using existing single sensors rather than requiring redundant sensor systems.
Solution Approach 2:
The system uses its own excitation command and existing sensors to perform self-diagnosis and abnormality detection. Rather than requiring external testing equipment or redundant sensors, the system leverages its internal resources to monitor its own health, reducing cost while maintaining detection capability.
Data Source
AI summary
Provided is a control device for a rotary machine including: a power feed unit configured to feed electric power in accordance with a power feed command to a rotary machine; a rotation-state detecting unit configured to detect a rotation state of the rotary machine; a torque detecting unit configured to detect an output torque output from the rotary machine; an abnormality determining unit configured to determine an abnormality in the rotation-state detecting unit or the torque detecting unit; and an excitation-command generating unit configured to generate an excitation command for oscillating the rotary machine, in which the power feed command is generated based at least on the excitation command, and the abnormality determining unit is configured to determine the abnormality in the detecting units based on a response of the rotation state and a response of the output torque to the excitation command.