Study on Instrumentation and Modeling of the Task Skills in Ultra-precision Assembly Tasks

这项研究的主要目标是深入分析和模拟高精度装配任务，该任务是具有非常窄的公差，即5微米或更小的销钉插入。目前，这项任务一直由熟练工人完成，因为目前还没有机器人或装配机可以像熟练工人那样以足够的精度和效率完成任务。本研究的一个主要目的是在高精度仪器的实验观察的基础上对插入任务进行深入分析。在此过程中，我们专注于收集和分析与插入任务相关的物理数据，以实现任务的自动化。在第一年，我们使用商业化的力传感器测量反作用力，并对熟练工人和非熟练工人进行比较。就力…而言，熟练者和非熟练者之间有很大的区别更多的燕鸥和它们施加的力量的大小。然而，所使用的力传感器不够灵敏，无法给我们所需的所有信息，即力矩的分辨率太低，无法提取任何有意义的信息。在研究的第二年，我们在重新设计了一种测量X轴和Y轴上的力矩的两轴力矩传感器后，进一步进行了实验。它的灵敏度足够高，而串扰和非线性特性足够低。此外，还使用了实时图像处理来获得对插入夹具倾斜度的更准确测量。结果，我们发现，不仅熟练的被试能比非熟练的被试更快地完成任务，而且前者倾向于最大限度地减少不必要的力量，而后者对偶然插入的搜索能力相当差。这一观察结果得到了以下事实的支持：熟练受试者的倾斜度变化或多或少直接会聚到一个目标上，而非熟练受试者倾向于做一个加工动作来找到准确的对准，这通常需要更多的时间和更低的能量效率。熟练的受试者处理任务的方式是高度一致和高效的。这种一致性和效率必须与他们所拥有的触觉敏感度有关。较少

Primary objective of this research is to thoroughly analyze and model a high-precision assembly task which is a peg insertion with a very narrow tolerance, i.e., 5 micron or less. Currently the task has been being performed by skilled workers because there is no robot or assembly machine available at this moment that can accomplish the task with a sufficient accuracy and efficiency that the skilled workers can deliver. A primary objective of the present study is to conduct in-depth analysis of the insertion task based on the experimental observations using high precision instruments. In doing so, we focused on collecting and analyzing the physical data associated with the insertion task in view of automatization of the task.During the first year, we measured reaction forces with a commercially available force sensor and did comparisons between skilled workers and unskilled workers. There were a lot of distinctions observed between the skilled and the unskilled in terms of the force pat … More terns and the magnitude of the forces they exerted. However, the force sensor used was not sensitive enough to give us all the information we needed, i.e., the resolution of moments was so low that any meaningful information could not be extracted. In addition to the force-related measurements, the inclination of the polygon mirror is measured as well.In the second year of the research, we further conducted experiments after newly designing a 2-axis moment sensor which measures moments about X-axis and Y-axis. Its sensitivity is high enough whereas its cross talk as well as nonlinear properties are sufficiently low. Also a real-time image processing is used to obtain more accurate measurement of the inclination of the insertion jig. As a result, we found that not only skilled subjects can finish the task faster than the unskilled, but also the former tends to minimize unnecessary forces while the latter rather poorly searches for an incidental insertion. This observation is supported by the fact that the inclination change of a skilled subject more or less directly converge to a goal while an unskilled subject tends to do a processing motion in order to find an exact alignment, which in general takes more time and is less energy efficient. The way the skilled subjects approach the task is highly consistent and efficient. Such consistency and efficiency must be related with tactile sensitivity which they possess. Less