Inertial Detection Circuit Using Dual-Frequency Diagnostic Signals

The patent divides the abnormality diagnosis function into separate processing units outside the detector structure. The detection signal processing and diagnostic signal processing are performed by distinct circuits in the signal processing unit, rather than embedding diagnosis functionality within the detector itself. This segmentation maintains detector simplicity while achieving comprehensive abnormality diagnosis capability through external processing.

The patent introduces an intermediary signal processing unit that acts as a mediator between the detector and the abnormality diagnosis function. This unit receives both detection signals and diagnostic signals from the detector, processes them separately through dedicated processing circuits, and performs abnormality diagnosis based on the processed diagnostic signals. The intermediary structure allows complex diagnosis functionality without complicating the detector configuration.

The patent employs periodic action by applying test voltage only during specific time intervals when abnormality diagnosis is required, rather than continuously. The signal processing unit periodically switches between processing detection signals (for inertial force measurement) and diagnostic signals (for abnormality diagnosis). This periodic separation ensures that test voltage application for diagnosis does not interfere with continuous inertial force measurement accuracy.

The patent implements preliminary action by performing abnormality diagnosis at predetermined intervals or before critical measurements. The control unit determines appropriate timing for applying test voltage based on operational conditions, ensuring diagnosis occurs when interference with inertial force measurement is minimal. This preliminary or scheduled diagnosis approach maintains measurement precision while achieving reliable abnormality detection.