The Study of a Magnetic Weighing System -- Simulation and Control

• Main Authors: Chang,Jing Yau, 張景堯
• Other Authors: Wang,Tsih Chang
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/31251332322010571261

碩士 === 國立清華大學 === 電機工程研究所 === 82 === In this thesis, the method of conversion from mass to current by electromagnetic force compensation is investigated. Main features are high accuracy, no mechanical loss, no friction, and ease of operation and calibration. Such a system has wide industrial application when precision mass measure ments are required. The entire weighing system consists of a mechanical structure and two electrical subsystems. In this work, the transfer function of the mechanical structure is derived. Moreover, electrical subsystems including position controller and measurement hardware have been redesigned and fabricated by using up-to-date electronic components. The detailed algorithm of measurement software is also presented. Then the weighing system is tested in the laboratory to verify its performance. The certificate interval number of the weighing system studied in this thesis is thirty thousand; the maximum capacity is three kilograms. It belongs to Class II of the National Suggestion No.76 of OIML. It takes 3 seconds for a mass reading. The performance of repeatability of reading, effect of off-center loading and hysteresis all meet the requirement of certificate specification.