gain-compensation-methodology-for-sinusoidal-scan-galvanometer-mirror

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques

Galvanometer mirrors are used for optical applications such as target tracking, drawing, and scanning control because of their high speed and accuracy. ...

Hitachi Industry & Control Solutions, Ltd.

We developed a novel real-time motion blur compensation system for the blur caused by high-speed one-dimensional motion between a camera and a target. The system consists of a galvanometer mirror and a high-speed color camera, without the need for any additional sensors. We controlled the galvanometer mirror with continuous back-and-forth oscillating motion synchronized to a high-speed camera. The angular speed of the mirror is given in real time within 10 ms based on the concept of background tracking and rapid raw Bayer block matching. Experiments demonstrated that our system captures motion-invariant images of objects moving at speeds up to 30 km/h.

Real-time high-speed motion blur compensation system based on back-and-forth motion control of galvanometer mirror.

We propose a method to achieve precise sine-wave path tracking for real-time motion-blur compensation to extend the corresponding frequency spectrum in proportional-integral-differential (PID) control by using a pre-emphasis technique. We calculate pre-emphasis coefficients in advance to follow a sine wave with a gain of 0 dB and multiply the input signal by these pre-emphasis coefficients. In experiments, we were thus able to extend the greatest frequency from 100 to 500 Hz and achieve gain improvement of approximately 3 dB at 400 and 500 Hz. For the application of inspection, we confirmed that motion blur is significantly reduced when the system operates at high frequency, and we achieved a responsiveness 3.3 times higher than that of our previous system.

Gain-compensated sinusoidal scanning of a galvanometer mirror in proportional-integral-differential control using the pre-emphasis technique for motion-blur compensation.

Takanoshin Watanabe

Hitachi Industry & Control Solutions, Ltd.

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques