Abstract
Linear permanent magnet synchronous motors (LPMSM), due to their merits of simple structure, direct drive capability, less noisy, high reliability, low frictional loss, high acceleration and deceleration capability, have now been gradually applied to various industrial control areas, such as high precision semiconductor manufacturing process equipment, and high speed transportation, automation control and medical device,…, etc. However, the dynamic performance of a LPMSM is still affected by the parameter variations, load disturbances as well as the friction force. Hence, various robust control strategies were proposed in literature to overcome this dilemma. In addition, in recent years digital electronic components are developed fastly and the microprocessors are widely applied. Therefore, various discrete-time control methods have gradually been developed for different applications. In this thesis, a fully digital robust control is proposed for LPMSM drives. Basically, the major contributions of this thesis may be summarized as follows. First, a double discrete-time fixed structure sliding mode controller is proposed for the robust control of both electrical and mechanical subsystems of LPMSM drives and the chattering effect are eliminated simultaneously. Second, by using the derived mathematical model of the LPMSM, the author proposes an adaptive load disturbance observer (ALDO) by using the concept of the law of momentum conservation to achieve a better tracking response. Finally, a prototype is also constructed to verify the validity of the proposed control. The proposed controller is implemented fully digitally using (DSP) TMS320F2812 to reduce hardware complexity, volume and to simplify the maintenance problems.