Sensorless position control of proportional solenoids

• Main Authors: Jia-Song Liu, 劉家嵩
• Other Authors: Jyh-Chyang Renn
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/13874231703090883275

碩士 === 國立雲林科技大學 === 機械工程技術研究所 === 87 === This Purpose of this paper is to control the proportional solenoid using merely the estimated position feedback. The stroke-type proportional valve uses a position sensor (LVDT) on one side of the armature to measure its actual position and to control the spool position. Consequently, the flow-rate through the valve can be exactly controlled. The position sensor, however, is a relatively expansive component . Therefore, we attempt to propose a calculating algorithm to estimate the position instead of measuring it by the LVDT. In this paper, we found that the inductance of the proportional solenoid decreases while the stroke increases. Thus, the position , inductance and current will all be measured and a table of them is built. Position is estimated from a two dimensional look up table of the incremental inductance and current. This method is successfully implemented in a proportional solenoid. The factors, which affect the accuracy of the estimation, as well as the methods of overcoming them are also described in this paper.