Singularity analysis of a 5-bar planar parallel mechanism based on a geometric measures

This paper proposes a new method for determining the singularity of a 5-bar planar PKM with revolute joints by taking geometric measures. A distinct feature of the proposed method is that it uses perpendicular distances between end-effectors, actuators, and determine singularities based on screw theory. The proposed method is intuitive and simple and thus can be used for analyzing the singularity of various PKMs © 2013 IEEE

Kalman-Filter-Based Tension Control Design for Industrial Roll-to-Roll System

This paper presents a robust and precise tension control method for a roll-to-roll (R2R) system. In R2R processing, robust and precise tension control is very important because improper web tension control leads to deterioration in the quality of web material. However, tension control is not easy because the R2R system has a model variation in which the inertia of the web in roll form is changed and external disturbances caused by web slip and crumpled web. Therefore, a disturbance observer (DOB) was proposed to achieve robustness against model variations and external disturbances. DOB is a robust control method widely used in various fields because of its simple structure and excellent performance. Moreover, the web passes through various process steps to achieve the finished product in the R2R process. Particularly, it is important to track the tension when magnitude of the tension varies during process. Feedforward (FF) controller was applied to minimize the tracking error in the transient section where tension changes. Moreover, the signal processing of a sensor using the Kalman filter (KF) in the R2R system greatly improved control performance. Finally, the effectiveness of the proposed control scheme is discussed using experimental results