Abstract
Compared with rotary motors, linear motors possess many advantages in linear motion driving applications, such as direct driving, low frictional loss, high position control accuracy, high speed, high acceleration and deceleration capability, maintenance free and large structural flexibility,*, etc. Till now, although a lot of types of linear motors have been developed, their designs, driving controls and applications are still not as mature as those for rotary motors. The major purpose of this thesis is to design and implement a linear brushless DC motor (LBDCM) drive. An experimental LBDCM driven one-dimensional table is established, wherein the Hall-effect sensors and linear encoder are employed to obtain the information of moving member position. For obtaining excellent position servo driving performance, a current-controlled voltage source inverter (VSI) with lowly-distorted sinusoidal output current is developed, the commutation instant tuning of inverter to yield better force generating capability of a LBDCM is also studied. It is known that the dynamic model is indispensable for performing the controller analysis and design. In this thesis, the dynamic modeling of a LBDCM drive based on physical derivation and estimation are described. Then accordingly, a two-degree-of-freedom controller (2DOFC) and a robust controller (RC) are proposed to yield good position tracking and regulation performances. After confirming the validity of the designed controllers by some simulations, the realization of controllers is made and the driving performances of the whole linear motor drive are demonstrated by some measured results.