Motor Controller Safety Circuit Abnormality Diagnosis

The patent segments the safety circuit into multiple independent logic gates (AND gates, OR gates, NOT gates) corresponding to different PWM signal paths. Each logic gate processes specific input signals (normal operation signals and safety stop signals) and produces output signals that are monitored by the control unit. This segmentation allows the control unit to identify which specific logic gate or signal path is causing the abnormality, thereby determining the cause of the abnormality while maintaining reliable safety detection.

The patent implements a feedback mechanism where the control unit continuously monitors the output signals from each logic gate and compares them with expected normal operation signals. When an abnormality is detected, the control unit diagnoses the specific cause by identifying which logic gate or signal path is problematic. This feedback loop enables the system to distinguish between genuine safety threats requiring shutdown and transient or diagnosable abnormalities that can be corrected, thereby preventing unnecessary motor shutdowns while maintaining safety.

The patent divides the safety circuit into multiple discrete logic gates (AND gates for upper switching elements, OR gates for lower switching elements, and NOT gates for safety stop signals), where each gate has a specific function and processes specific inputs. The control unit monitors the output signal from each individual logic gate separately. This segmentation transforms a complex multi-input system into a series of simple, monitorable units, making it easier to diagnose failures by identifying which specific gate is producing an abnormal output, thereby reducing diagnostic complexity despite maintaining high adaptability.

The patent combines the monitoring function with the existing control unit that already manages PWM signal generation and motor control. The control unit is enhanced to include monitoring capabilities that read output signals from logic gates and compare them with expected values. By merging the monitoring function into the existing control unit rather than adding a separate monitoring system, the patent achieves high diagnosis precision while minimizing the increase in overall system complexity. The control unit utilizes its existing processing capabilities to perform both control and monitoring functions.