Motor Drive System Angle Sensor Switching for Noise Resilience
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Solution Overview
Problem
The reliability of motor drive systems in electric vehicles is compromised due to electromagnetic and electrostatic noise affecting angle sensors, leading to inefficient drive motor control and potential system failure, especially when sensors are displaced or malfunctioning.
Innovation Solution
A motor drive system with multiple angle sensors and a controller-based angle sensor switching unit that selects and activates alternative sensors in case of abnormality, and switches to a sensorless mode if all sensors fail, ensuring continuous rotational control of the drive motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single angle sensor is used to detect the relative rotational angle, then the device complexity is low, but the reliability deteriorates due to electromagnetic and electrostatic noise affecting the sensor
Solution Approach 1:
The system divides the angle sensing function into multiple independent sensors (first angle sensor and second angle sensor) instead of relying on a single sensor. This segmentation allows the system to detect angles through multiple channels, reducing the impact of electromagnetic and electrostatic noise on any single sensor while maintaining overall system reliability.
Solution Approach 2:
The controller dynamically switches between different angle sensors based on detected abnormalities. When noise or failure is detected in one sensor, the system changes the operational parameter by selecting an alternative sensor, thereby maintaining reliable angle detection despite adverse electromagnetic or electrostatic conditions.
2Reliability
If multiple angle sensors are provided to improve reliability, then the reliability improves, but the device complexity increases due to additional sensors and switching control
Solution Approach 1:
The system implements dynamic sensor selection where the controller actively monitors the operational status of multiple angle sensors and switches between them based on real-time conditions. This dynamic approach allows the system to maintain simplicity by using only one sensor at a time while having backup sensors available, thus improving reliability without permanently increasing operational complexity.
Solution Approach 2:
The controller acts as an intermediary that manages multiple angle sensors. It monitors sensor outputs for abnormalities caused by electromagnetic or electrostatic noise and automatically switches between sensors or engages sensorless control, thereby shielding the overall system from the complexity of managing multiple sensors while maintaining high reliability.
3Measurement precision
If the angle sensor is affected by electromagnetic and electrostatic noise, then the measurement precision deteriorates, but the sensor structure remains simple
Solution Approach 1:
The system prepares multiple angle sensors in advance as backup options. When electromagnetic or electrostatic noise affects one sensor and degrades measurement precision, the controller has pre-configured alternative sensors ready to switch to, thereby cushioning the system against precision loss without requiring complex noise filtering in the sensor structure itself.
Solution Approach 2:
The controller continuously monitors the output signals from angle sensors to detect abnormalities caused by electromagnetic or electrostatic noise. This feedback mechanism allows the system to identify when measurement precision is deteriorating and automatically switch to an alternative sensor or sensorless control mode, maintaining accurate angle detection despite the presence of harmful electromagnetic or electrostatic factors.
4Adaptability or versatility
If sensorless control is implemented as backup, then the adaptability improves, but the measurement precision may deteriorate without angle sensors
Solution Approach 1:
The system dynamically adapts its control mode based on sensor availability. When all angle sensors are affected by noise or fail, the controller switches from sensor-based control to sensorless control, demonstrating adaptability. The system maintains operational capability across different conditions, though measurement precision may be reduced in sensorless mode compared to sensor-based control.
Data Source
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AI summary
To provide a motor driving system for an electrically powered automotive vehicle, in which the drive motor is rotationally controlled to increase the reliability, the use is made of an angle sensor for detecting the relative rotational angle between a stator and a rotor of a drive motor for driving the electric vehicle and a controller for controlling the rotation of the drive motor on the basis of the relative rotational angle detected by the angle sensor. The angle sensor is provided in a plural number. The controller includes an angle sensor switching unit operable to select and activate one of the plurality of the angle sensors and then to switch over to an activation of another one of the angle sensors in the event that the one of the angle sensors is determined abnormal.