BLDC Motor Control Using Sensor and Electrical Parameter Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brushless direct current (BLDC) motor control systems face challenges in accurately determining the rotor electrical angle, especially under varying operating conditions, due to the reliance on position sensors which are costly, prone to noise interference, and require additional hardware, while sensorless methods may not provide accurate estimates across all speed ranges.
Innovation Solution
A method and system that generate motor controlling parameter measurements using both position sensor signals and motor electrical parameters, allowing for robust commutation control by determining a first measurement based on sensor data and a second measurement based on electrical parameters, with the option to switch to sensorless methods when sensor data is abnormal, ensuring accurate motor control across a wide range of conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple Hall Effect sensors are used to determine rotor position, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the position sensing function from dedicated Hall Effect sensors and implements it through the existing current sensors by analyzing back EMF signals. This eliminates the need for separate position sensors while maintaining measurement capability through electrical parameter analysis.
Solution Approach 2:
The current sensors originally designed for motor control are made multi-functional by enabling them to perform both current measurement and position detection through back EMF analysis. This universal approach allows a single sensor system to provide multiple functions, reducing overall device complexity.
2Measurement precision
If Hall Effect sensors are used for rotor position detection, then measurement precision is improved, but loss of information increases due to noise interference
Solution Approach 1:
The patent converts the harmful effect of noise interference into a beneficial signal source by using back EMF signals, which naturally contain position information. Instead of fighting against noise, the system utilizes the electromagnetic induction phenomenon to generate useful position data that is inherently less susceptible to interference.
3Device complexity
If sensorless techniques are used to determine rotor position, then device complexity is reduced, but measurement precision deteriorates under varying operating conditions
Solution Approach 1:
The patent implements a dynamic control strategy that adapts between sensor-based and sensorless modes depending on operating conditions. The system transitions from sensorless estimation at low speeds to sensor-based measurement at higher speeds, optimizing both complexity and precision across the entire operating range.
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 enhances the accuracy and reliability of motor control, reducing the risk of motor stall events and maintaining stable operation in BLDC motors, particularly in applications like unmanned aerial vehicles (UAVs), by combining sensor-based and sensorless methods for determining electrical angles and motor speed.
Implementation Method 1
using multiple rotor position sensors, such as low-resolution Hall Effect sensors
Implementation Method 2
a common sensorless technique known as the 'zero crossing' method involves estimating the rotor electrical angle based on the back EMF (electromotive force) produced when the permanent magnet of the rotor passes an un-energized winding
Data Source
AI summary
A method of controlling a motor includes determining a first motor controlling parameter measurement based on a signal received from a position sensor, determining a second motor controlling parameter based on one or more motor electrical parameters, and controlling operation of the motor based on at least one of the first motor controlling parameter measurement or the second motor controlling parameter measurement.