Actuator Tilt Abnormality Detection Using Counter EMF
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Solution Overview
Problem
Existing actuator devices face issues with proper operation due to changes in magnetic force caused by demagnetization or positional deviations, which are not effectively detected by traditional resistance value measurements.
Innovation Solution
An abnormality detection method that utilizes a detection coil and a magnetic field to generate a counter electromotive force, allowing for the determination of abnormalities such as demagnetization or positional deviations by analyzing the output values during resonant and non-resonant driving signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If resistance value measurement is used for abnormality detection, then the detection method is simple, but it cannot detect abnormalities caused by demagnetization or positional deviation
Solution Approach 1:
The patent changes the detection parameter from resistance value to counter electromotive force (CEMF). By measuring CEMF during resonant and non-resonant driving states, the system can detect abnormalities in magnetic force caused by demagnetization or positional deviation, which resistance measurement cannot detect. This parameter change enables comprehensive abnormality detection while maintaining practical implementation feasibility.
2Reliability
If counter electromotive force analysis is used, then abnormality detection reliability is improved, but the device complexity increases
Solution Approach 1:
The patent utilizes the detection coil's own counter electromotive force as the detection signal, eliminating the need for separate sensors or measurement systems. The CEMF naturally generated in the detection coil during driving provides all necessary information for abnormality detection, including magnetic force changes and positional deviations. This self-service approach achieves high detection reliability without significantly increasing device complexity.
Solution Approach 2:
The detection coil serves multiple functions: it acts as both a drive coil for actuating the movable portion and as a detection coil for measuring counter electromotive force. This multi-functionality eliminates the need for separate detection components, reducing overall device complexity while enabling comprehensive abnormality detection through CEMF analysis during resonant and non-resonant driving states.
3Measurement precision
If resonance driving is applied, then the detection sensitivity is improved, but the control complexity increases
Solution Approach 1:
The patent employs periodic resonant driving signals at specific frequencies to excite the movable portion. By applying sinusoidal drive signals at resonant frequencies and analyzing the resulting counter electromotive force, the system achieves high detection sensitivity for abnormalities. The periodic nature of resonant driving creates distinct CEMF patterns that make abnormality detection more precise while maintaining manageable control complexity through frequency-based excitation.
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 method enables more reliable detection of abnormalities in actuator devices, including those caused by demagnetization or positional deviations, by using counter electromotive force analysis, thereby ensuring proper device operation.
Implementation Method 1
an output value corresponding to a counter electromotive force generated in the detection coil is acquired
Data Source
AI summary
An actuator device includes: a first movable portion; a second movable portion; a magnet portion; a coil; and a controller configured to supply a first drive signal for resonantly driving the first movable portion and a second drive signal for non-resonantly driving the second movable portion to the coil. An abnormality detection method includes: supplying the second drive signal to the coil by the controller; acquiring an output value corresponding to a counter electromotive force generated in the coil while the second drive signal is supplied to the coil; and determining whether an abnormality has occurred in a tilted state of the second movable portion on the basis of the second drive signal supplied to the coil and the acquired output value.