Development of the Linear Motor Drive System

• Main Authors: Fu-Chun Chang, 張富鈞
• Other Authors: Ying-Chiang Wu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/78524588970741920387

碩士 === 逢甲大學 === 自動控制工程學系 === 89 === Linear motors give mechanical devices high dynamic speeds and accelerations, high accuracy position and exceptionally smooth motion in linear motion driving application. But the design and driving skills are not as popular as that for traditional rotary motors. With the development of the microcomputer and power electrical industry, the design of the linear motor driver and controller system is still some key issues being worthy of further improvement. The purpose of this paper is to implement a linear brushless DC motor (LBDCM) driving system, including drive circuits and controller. First, we established a single axis position stage. Then a current-controlled voltage source PWM inverter,including a current-controlled PWM signal generating circuit and a lock-out circuit is properly designed. In order to obtain the information of moving member position, a linear encoder and Hall-effect sensor signals are employed. Finally, the current command is kept in synchronization with the back electromotive forces. In this way, the correct current command is generated to make the primary moving magnetic field in perpendicular to the secondary flux and produce the maximum force. In this paper, the practical realization of a sliding mode controller based on variable structure systems is applied. The dynamic modeling of the LBDCM system is obtained by estimation from measurement. When the sliding mode occurs, the system will be forced to slide along or near the vicinity of the switching surface. The system became robust and insensitive to the disturbances and variations during the task. Simulation and experimental results demonstrate that the control method has more robust and the valid than a PID control.