@article {620, title = {Twin-beam real-time position estimation of micro-objects in 3D}, journal = {Measurement Science and Technology}, volume = {27}, year = {2016}, month = {12}, pages = {127003}, abstract = {

Various optical methods for measuring positions of micro-objects in 3D have been reported in the literature. Nevertheless, the majority of them are not suitable for real-time operation, which is needed, for example, for feedback position control. In this paper, we present a method for real-time estimation of the position of micro-objects in 3D; the method is based on twin-beam illumination and requires only a very simple hardware setup whose essential part is a standard image sensor without any lens. The performance of the proposed method is tested during a micro-manipulation task in which the estimated position served as feedback for the controller. The experiments show that the estimate is accurate to within ~3 μm in the lateral position and ~7 μm in the axial distance with the refresh rate of 10 Hz. Although the experiments are done using spherical objects, the presented method could be modified to handle non-spherical objects as well.

}, issn = {1361-6501}, doi = {10.1088/0957-0233/27/12/127003}, author = {Gurtner, Martin and Ji{\v r}{\'\i} Zem{\'a}nek} }