廖曉文1， 劉  美1， 曾  光2， 田志波1
（1. 廣東石油化工學(xué)院自動(dòng)化系，廣東 茂名 525000； 2. 廣州東芝白云菱機(jī)電力電子有限公司，廣東 廣州 510460）
摘  要：針對(duì)混合式步進(jìn)電機(jī)開環(huán)控制容易出現(xiàn)丟步的問題，利用冪次函數(shù)代替開關(guān)函數(shù)，設(shè)計(jì)基于改進(jìn)滑模觀測(cè)器的丟步檢測(cè)算法。證明該觀測(cè)器在較大電流觀測(cè)偏差時(shí)是一變?cè)鲆娴幕Ｓ^測(cè)器，在較小電流觀測(cè)偏差時(shí)具備低通濾波功能，可消除抖振現(xiàn)象。同時(shí)，通過觀測(cè)反電動(dòng)勢(shì)得到電角度，并利用冪次函數(shù)設(shè)置較大的邊界層厚度，將電角度收斂到π/2整數(shù)倍的區(qū)域，可直接根據(jù)觀測(cè)結(jié)果判定電機(jī)有無丟步。實(shí)驗(yàn)結(jié)果驗(yàn)證了該方法在低細(xì)分、寬調(diào)速范圍的有效性。
關(guān)鍵詞：滑模觀測(cè)器；冪次函數(shù)；混合式步進(jìn)；丟步檢測(cè)
中圖分類號(hào)：TM383.6；TM930.12；TP277；TP391.97    文獻(xiàn)標(biāo)志碼：A     文章編號(hào)：1674-5124（2013）03-0088-04
Lost steps detection based on sliding-mode observer for hybrid stepper motors
LIAO Xiao-wen1， LIU Mei1， ZENG Guang2， TIAN Zhi-bo1
（1. Automation Department，Guangdong Institute of Petrol-Chemical Technology，Maoming 525000，China；
2. Guangzhou Toshiba Baiyun Ryoki Power Electronics Co.，Ltd.，Guangzhou 510460，China）
Abstract: As the lost steps problem exists in hybrid stepper motors in their open loop control mode， the lost steps detection was designed by replacing the switching function with power function and based on improved sliding-mode observer. It was proven that the improved observer is a variable gain sliding-mode observer when the current observation errors are large. When the current observation errors are smaller， the improved observer has a low-pass filtering feature and the chattering phenomenon can be eliminated. The estimated back EMF is used to obtain electrical angle and the larger boundary layer thickness is set by power function. Thus， the electrical angle can be convergence to integer multiple area of π/2. So any lost steps can be obtained from observations directly. The experimental results verify the validity of the method in the low subdivision and wide speed range.
Key words: sliding-mode observer； power function； hybrid stepper； lost steps detection