Pattern-based vision for microrobotic manipulators calibration and servoing

Abstract

This paper presents recent results obtained with a visual method allowing absolute position measurements at nanoscale. Based on the direct phase analysis of pseudo-periodic patterns, this approach enabled fast measurements of position with large range-to-resolution ratios. Applications include microrobotic manipulators calibration and visual servoing but also microforce measurement by using a compliant structure. Rangeto-resolution ratio of 10 5 are typically overcome. For instance, the experiments have demonstrated a sub-nanometric resolution over a range of 168 µm, as well as a resolution below 50 nN for a 50 mN range for force measurement.

High-efficiency sub-microscale uncertainty measurement method using pattern recognition

“…This technique overcomes the shortcomings of limited charge coupled device (CCD) pixel count and image size, out of focus areas at the boundaries of the image, and vertical motion of the slide out of the focal plane. A novel 2D intertwined pattern was also proposed for two-axis precision measurement [15][16][17]. This method uses a pseudo-periodic pattern observed with a microscope head and a CCD camera.…”