Micro well-plates are an apparatus commonly used in chemical and biological experiments that are a few centimeters thick and contain wells or divets. In this paper, we aim to solve the task of placing the well-plate onto a well-plate holder (referred to as holder). This task is challenging due to the holder's raised grooves being a few millimeters in height, with a clearance of less than 1 mm between the well-plate and holder, thus requiring precise control during placing. Our placing task has the following challenges: 1) The holder's detected pose is uncertain; 2) the required accuracy is at the millimeter to sub-millimeter level due to the raised groove's shallow height and small clearance; 3) the holder is not fixed to a desk and is susceptible to movement from external forces. To address these challenges, we developed methods including a) using tactile sensors for accurate pose estimation of the grasped well-plate to handle issue (1); b) sliding the well-plate onto the target holder while maintaining contact with the holder's groove and estimating its orientation for accurate alignment. This allows for high precision control (addressing issue (2)) and prevents displacement of the holder during placement (addressing issue (3)). We demonstrate a high success rate for the well-plate placing task, even under noisy observation of the holder's pose.

翻译：微孔板是化学与生物实验中常用的一种数厘米厚、表面带有凹孔或浅槽的实验器具。本文旨在解决将微孔板精确放置到微孔板支架（以下简称支架）上的任务。由于支架凸起的导轨高度仅为数毫米，且微孔板与支架之间的间隙不足1毫米，因此放置过程需要极高的控制精度，这构成了任务的主要挑战。本放置任务面临以下难点：1）支架的检测位姿存在不确定性；2）因导轨高度低、间隙小，所需精度需达到毫米甚至亚毫米级别；3）支架未固定于实验台，易受外力干扰发生位移。针对上述问题，我们开发了以下方法：a）利用触觉传感器对抓取中的微孔板进行精确位姿估计，以解决难点（1）；b）通过使微孔板在目标支架的导轨上滑动并保持接触，同时估测支架的朝向以实现精确对齐。该方法既能实现高精度控制（解决难点（2）），又能防止放置过程中支架发生位移（解决难点（3））。实验证明，即便在支架位姿观测存在显著噪声的情况下，该方案仍能实现极高的微孔板放置成功率。