Design of a low-vibration micro-stepping controller for dom-camera

Fast, smooth and accurate motion is the important properties of dom-camera (DC). In the case of a high ratio zoom lens, low vibration characteristic is an also crucial point in driving pan-tilt mechanism in DC. In this paper, a novel micro-stepping controller with a function of adjusting reference current was designed using field programmable gate arrays (FPGA) technology for high zoom ratio dom-camera. The proposed variable reference current (VRC) control scheme reduces vibration and increases maximum acceleration without missing steps. By employing VRC control scheme, the vibration in low speed could be significantly minimized. The proposed controller can also make very high speed of 378k pps micro-step driving, and increase maximum acceleration in motion profiles.