The Study On Electric-compass That Based On The DSP And Motor's Micro-stepping Controlling Technology

With the fast development of international and domestic marine transportation business, the safety of navigation is considered more and more serious by us. The direction of ship is the most important factor. As a navigation equipment of ship , the electric-compass is one of the essential equipments of the voyage navigates, so it has a prominent position in the voyage. Its applied performance directly affects the safety of navigation and the completion of sailing task in scheduled date.With its special features in the construction, stepper motor is widely used in the system that without speed sensors and location sensors to achieve precise positioning of the non-feedback controlling central or synchronous operation. We adopted the regulation that we can conveniently achieve precise position by sending to the stepper motor a given number of electrical pulse and by adjusting the step pulse frequency to control its speed .These characters can be contribute to make the device or equipment miniaturization and low-cost, so they are widely spread in many areas.The stepper motor's micro-stepping driver is a kind of driving technology that can effectively improve the step precision and characteristic of low frequency. It is mostly used when the equipments require high-precision, low noise or low vibration system, and it is being a more and more popular driving technology.Based on technologies such as stepper motor controller, PWM inverter and DSP, We analysis the using of micro-stepping driving technology to improve operational performance,discuss the principles of SPWM inverter for stepper motor with invariable torque micro-stepping driver, and propound a new all-digital PWM technology.Drawing upon these technologies and also the integrated DSP controlling method, a novel motor control strategy for electric compass reviewer are proposed .In the thesis, we develop a DSP-based digital controlling system for a two-phase hybrid stepper motor that is mainly constructed from a TMS320LF2407A DSP which is used as the core of control parts and a dual full-bridge driver L298N which is used as a driving parts. Based on the approach, the system's whole architecture, the design ofhardware and software are introduced in detail.In finally, the reliability and stepper accuracy of this new control system are tested. The results show that the system can effectively satisfy the fixed position accuracy of customer request, represses movement noise and mechanical vibration. Meanwhile, the high integrity of hardware system and the realization of the invariable torque micro-stepping technology of stepper motor can effectively reduce the cost ,improve the system's reliability and relevance.