Motor Torque Ripple Suppression Using Frequency-Selective Periodic Signals
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Solution Overview
Problem
Existing motor control systems in inkjet and image reading apparatuses face challenges in efficiently suppressing torque ripple, which requires extensive measurement and adjustment due to varying frequency components and individual differences among devices, leading to time-consuming operations.
Innovation Solution
An electronic apparatus with a motor, encoder, control unit, selection unit, generation unit, and acquisition unit that generates periodic signals to suppress specific frequency components of torque ripple, using a threshold value-based approach to identify and correct speed variations, thereby reducing the need for extensive measurement and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a correction table method is used to suppress torque ripple, then torque variation can be reduced, but extensive measurement and adjustment operations are required due to various frequency components and individual differences among devices
Solution Approach 1:
The system performs preliminary measurement and generation of correction values during a calibration phase, storing these correction values in memory. During actual operation, the stored correction values are directly applied without requiring repeated measurements, thus reducing time loss while maintaining reliable torque ripple suppression
Solution Approach 2:
The system measures speed variation at multiple frequencies simultaneously and identifies specific frequency components that contribute to torque ripple. By changing the approach from general speed correction to frequency-specific correction based on measured parameters, the system achieves effective torque ripple suppression with reduced adjustment operations
2Reliability
If multiple frequency components of torque ripple are suppressed, then comprehensive torque variation reduction is achieved, but the complexity of measurement and control increases
Solution Approach 1:
The system segments the torque ripple problem by analyzing speed variation at multiple discrete frequencies independently. By measuring and correcting each frequency component separately through band-pass filters and individual correction values, the system achieves comprehensive torque suppression while keeping the control structure manageable and modular
Solution Approach 2:
The system introduces an intermediary correction table that stores pre-calculated correction values for different frequency components. This intermediary structure mediates between the complex multi-frequency torque ripple problem and the simple control execution, reducing the apparent complexity of the control system while maintaining comprehensive suppression capability
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 solution effectively suppresses torque ripple by generating tailored periodic signals based on selected frequencies, improving motor control efficiency and reducing the time and effort required for calibration across different devices.
Implementation Method 1
an encoder configured to output a signal in response to movement of the mechanism
Implementation Method 2
a control unit configured to execute feedback control over driving of the motor according to the signal and a command value
Implementation Method 3
a generation unit configured to generate a periodic signal including the frequency to be measured that is selected by the selection unit and a periodic signal including the frequency to be suppressed that is selected by the selection unit
Implementation Method 4
an acquisition unit configured to output the periodic signal generated by the generation unit to the control unit and to acquire a parameter relating to the frequency included in the periodic signal
Data Source
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AI summary
To suppress torque variation including various frequency components, a lot of measuring and adjusting operations are necessary, and this takes much time and trouble. An electronic apparatus includes a selection unit configured to select, on the basis of a threshold value relating to speed variation of the mechanism and threshold values relating to a plurality of frequencies that constitute the speed variation, a frequency to be measured and a frequency to be suppressed, from the plurality of frequencies, a generation unit configured to generate a periodic signal including the frequency to be suppressed that is selected by the selection unit, and an acquisition unit configured to output the periodic signal generated by the generation unit to the control unit and to acquire a parameter relating to the frequency included in the periodic signal.