Study On Brushless DC Motor Propeller And Control System Of Doubly-revolved Underwater Robot

At present, the motors used in the ocean robots are always the permanent magnet DC motor. Though, as the propeller, the permanent magnet DC motors have advantages such as good function of speed adjustment, however the conventional DC motor uses mechanic method to converse it. The structure of motor has the inherent limitation with brush and commutation and it makes that the motor has short life, poor reliability, difficult to maintain and high cost. In addition, DC motors have some disadvantages such as large volume, heavy structure, low intensity of power and less capacity. So DC motor propellers haven't more and more satisfied the requests of the motors used in the ocean robots. Besides brushless DC motor has the same advantage as conventional DC motor, it has the following outstanding features, which has small volume, light structure, high intensity of power and large capacity. So, to use permanent magnetic brushless DC motor as the propeller of the ocean robot instead of the permanent magnet DC motor has a great significance both in theory and in practice.This thesis describes a control system of the brushless DC motor, which adopts a 32 bit TMS320F2812 DSP of TI company as the digital motor control. According to the demand of the system structure and control regulation of brushless DC motor , a permanent magnetic brushless DC motor of double-revolve ocean robot was designed. And for a brushless DC motor of the 92BL series, which is used for the experimentation, a control system's blue print was put forward. Then, the hardware and software design of the system according to the preceding solutions are discussed in detailed. The thesis also introduced the control circuit of DSP TMS320F2812, the drive circuit of motor and the sampling circuit of position and current, and software programming as well. At last the testing phenomenon when the control system running is observed and the experimental results are analyzed.Because of the using of DSP technique, the system of the brushless DC motor used on the ocean robot not only makes the system acquire the high accuracy, high dependability, but also simplifies the system structure, and increases the system function. It has extensively applied value to the research of the control system.