H-Bridge Motor Driver Abnormality Detection via Current Sensing
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Solution Overview
Problem
Existing motor driving devices lack effective methods to detect abnormalities and implement safety algorithms, which can lead to damaged motors and abnormal steering system operations.
Innovation Solution
A motor driving device incorporating an H-bridge circuit with current sensors and a controller that samples sensing signals over specific periods to determine abnormality and executes a fail-safe algorithm when anomalies are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If motor driving device operates without abnormality detection, then device complexity is reduced, but reliability deteriorates due to potential motor damage and abnormal steering operations
Solution Approach 1:
The patent implements preliminary abnormality detection by monitoring current characteristics before actual motor damage or steering failure occurs. The controller continuously acquires current sensing signals during different switching periods and compares them to detect potential abnormalities in the H-bridge circuit, performing the detection action in advance to prevent catastrophic failures.
Solution Approach 2:
The patent establishes a feedback mechanism where the controller continuously monitors current sensing signals from the H-bridge circuit and uses this feedback information to detect abnormalities. The sensing signals are fed back to the controller which analyzes current characteristics during different switching periods to identify potential faults in the motor driving device.
2Measurement precision
If current sensing is performed during all switching periods, then measurement precision is improved, but use of energy increases due to continuous sensing operations
Solution Approach 1:
The patent applies partial action by performing current sensing only during specific switching periods (first and second periods when particular switches are turned on) rather than continuously during all switching periods. This selective sensing approach captures sufficient current characteristics for abnormality detection while reducing unnecessary sensing operations and associated energy consumption.
3Object-affected harmful factors
If H-bridge circuit operates without abnormality detection, then device complexity is reduced, but object-generated harmful factors increase due to motor damage and abnormal steering control
Solution Approach 1:
The patent detects abnormalities in the H-bridge circuit before they cause motor damage or abnormal steering control. By continuously monitoring current sensing signals and comparing characteristics during different switching periods, the system identifies potential faults in advance, preventing the generation of harmful effects from motor failure or steering system malfunction.
Data Source
AI summary
The present disclosure relates a motor driving device that includes: an H-bridge circuit that includes first and second legs, each of which has one pair of switches, and supplies a driving current to a motor; a current sensor disposed between the H-bridge circuit and a voltage source; and a controller that acquires a first sensing signal from the current sensor for a first period of time during which a turn-on signal is supplied to a first switch disposed in the first leg or a fourth switch disposed in the second leg, to acquire a second sensing signal from the current sensor for a second period of time during which a turn-on signal is supplied to a second switch disposed in the first leg or a third switch disposed in the second leg, and determines an abnormality in the H-bridge circuit.