Sensorless Motor Rotor Position and Failure Detection via Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control systems for sensorless DC brushless motors face challenges in detecting failures promptly, leading to extended downtime due to the need for multiple test patterns to determine motor failure.
Innovation Solution
A motor control apparatus that includes an excitation unit to measure changes in inductance of coils, a measurement unit to generate data, and a determination unit to assess the rotor position and potential failures, allowing for efficient failure detection without prolonged downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple test patterns are used to determine motor failure, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent extracts the failure determination process from the motor operation state, enabling it to be performed independently during idle periods. The control unit can determine motor failures by analyzing voltage commands and current values without requiring the motor to be in a specific operational state, thus reducing downtime while maintaining detection accuracy through multiple parameter analysis.
Solution Approach 2:
The patent implements preliminary failure determination by continuously monitoring and storing voltage commands and current values during motor operation. When idle time occurs, the control unit performs failure determination using previously collected data, eliminating the need to wait for specific motor states and reducing overall downtime while maintaining comprehensive failure detection capability.
2Productivity
If motor failure determination is performed during motor operation, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
The patent implements feedback by continuously monitoring motor operation parameters (voltage commands and current values) and using this data for failure determination. The control unit compares actual motor responses against expected performance patterns, enabling accurate failure detection during normal operation without interrupting productivity. This feedback mechanism maintains measurement precision while the motor remains operational.
3Device complexity
If simple measurement methods are used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent uses voltage commands and current values as intermediary parameters to infer motor health status. Instead of directly measuring complex motor internal states, the control unit analyzes these readily available electrical parameters to determine failures. This intermediary approach maintains measurement precision while avoiding the need for complex additional measurement devices or sensors.
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
Enables rapid determination of rotor position and motor failure, reducing downtime and improving operational efficiency by using measured data to identify coil failures and other issues.
Implementation Method 1
a measurement unit configured to measure a physical amount that changes according to an inductance of at least one of a plurality of coils that make up the plurality of excitation phases
Data Source
AI summary
A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of a motor; a measurement unit configured to measure a physical amount that changes according to an inductance of at least one of a plurality of coils that make up the plurality of excitation phases by exciting each of the plurality of excitation phases, and generate measured data that includes measurement values of the physical amount measured for the plurality of excitation phases; and a determination unit configured to determine, based on the measured data, a rotational position of a rotor of the motor and whether or not at least one of the motor and the excitation unit has a failure.