Visually guided microassembly using optical microscopes and active vision techniques

Robust micromanipulation strategies are needed in order to overcome a potential technology barrier to the commercial development of complex microelectromechanical devices. In this paper we present experimental results that investigate the use of high resolution optical systems with controllable intrinsic and extrinsic parameters for microassembly applications. Results of two active vision strategies, depth-from-defocus and visual servoing, using an optical microscope are presented. Depth-from-defocus results indicate a repeatability of 8 μm (just one order of magnitude greater than the wavelength of light) is achievable. Visual servoing results demonstrate visually servoed motion over large scales of motion with submicron repeatability has been achieved. The ability to servo over large scales is made possible by the use of a unique formulation of the image Jacobian for an optical microscope