Design and implementation of an abnormal load torque observer for a servo drive

M. Y. Cheng, M. C. Tsai, R. T. Shieh, Y. Y. Sun

Research output: Contribution to journalArticlepeer-review


In manufacturing processes, human error and abnormal operation often produce excessive amounts of torque on servomechanisms. These abnormal loads may damage the work piece or tool and sometimes the entire servo system. Fault detection is beginning to receive considerable attention for its usefulness in ensuring the safety and reliability of servo systems. The aim of this research is to investigate the problem of abnormal load detection for servo control systems with permanent magnet brushless motors (PMBLM). The unknown input observer technique is employed to estimate the abnormal load torque exerted during the manufacturing process, while the appropriate control can be applied to prevent or reduce the risk of damaging the servo system. The experimental results indicate that the presented approach can successfully detect abnormal load torque from a servo system without using any torque sensors.

Original languageEnglish
Pages (from-to)99-111
Number of pages13
JournalJournal of the Chinese Institute of Electrical Engineering, Transactions of the Chinese Institute of Engineers, Series E/Chung KuoTien Chi Kung Chieng Hsueh K'an
Issue number2
Publication statusPublished - 1999 Jan 1

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering


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