Study on detection of earthquake using DI value and its application to switching control for air type anti-vibration apparatus

In semiconductor manufacturing, air type-vibration apparatuses (AVAs) are widely employed. When an earthquake occurs, the AVAs have to be stopped in order to avoid serious damage to semiconductor exposure machines. Spectrum intensity (SI) value is the metric effective for the detection of earthquake though it takes time to calculate this value. To avoid long computation time, this paper uses destructive intensity (DI) value instead of SI value. Simulation demonstrates that DI value, whose computation time is short, can be applied to switching control for AVAs.