Brushless Motor Control Position Error Correction
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Solution Overview
Problem
Existing motor control systems for brushless motors face challenges in correcting rotor position detection errors at low cost and high accuracy, particularly due to dispersion issues with Hall sensors and magnetic poles, where it is difficult to determine which sensor is closest to the theoretical value.
Innovation Solution
A motor control apparatus and method that utilize a control part to correct position detection signals from multiple sensors using a predetermined correction coefficient, adding a correction angle to the power distribution control's advance angle and selecting an appropriate output pattern based on this correction, ensuring synchronization with position detection signal timing and using two distinct output patterns to maintain consistent switching element states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position displacement is measured by confirming Hall sensor output while rotating the rotor, then detection error can be corrected, but additional measurement devices and costs are required
Solution Approach 1:
The Hall sensors themselves are used to measure the position displacement by detecting changes in output during rotor rotation, eliminating the need for separate measurement devices. The system serves its own measurement needs using existing components.
Solution Approach 2:
The control part acts as an intermediary that processes the Hall sensor outputs during rotation to calculate position displacement, then uses this information to correct the detection errors without requiring direct physical measurement devices.
2Measurement precision
If correction is performed using cycle measurement or theoretical comparison, then dispersion between sensors and magnetic poles can be corrected, but it is impossible to identify which sensor is closest to the theoretical value
Solution Approach 1:
The control part continuously monitors the outputs of all Hall sensors during rotor rotation and uses this feedback information to determine which sensor produces outputs closest to theoretical values, thereby identifying the most accurate sensor while simultaneously correcting errors across all 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
This approach allows for accurate and cost-effective correction of rotor position detection errors, enhancing the precision and reliability of motor control while maintaining flexibility in power distribution control patterns.
Implementation Method 1
a plurality of Hall sensors or the like... detecting a position of magnetic poles that are included in the rotor or a position of magnetic poles of a sensor magnet
Data Source
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AI summary
A motor control apparatus that is configured to perform a power distribution control on three-phase coils of a brushless motor and that is configured to perform a rotation control of a rotor includes: a plurality of switching elements that are arranged to be capable of switching a current which is allowed to flow through the coils; a plurality of sensors that are configured to detect a rotation position of the rotor; and a control part that is configured to output a drive signal for controlling a power distribution pattern of each switching element according to a position detection signal which is obtained by correcting a position detection signal as an output of the plurality of sensors by using a predetermined correction coefficient, wherein the control part is configured to add a correction angle that corresponds to a difference between the position detection signals before and after correction of a predetermined sensor among the plurality of sensors to a setting value of an advance angle of the power distribution control and select an output pattern that includes a plurality of power distribution patterns and that is used when selecting the power distribution pattern, from a plurality of different output patterns in accordance with the advance angle to which the correction angle is added and a power distribution angle of the power distribution control.