Implementation and Performance Testing of A DC Motor Driver for Underwater Thrusters

• Main Authors: Jyun-siang Gao, 高鈞祥
• Other Authors: Hsin-Hung Chen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/84808527555873123117

碩士 === 國立中山大學 === 海下科技暨應用海洋物理研究所 === 99 === The control of a remotely operated vehicle (ROV) for moving stably at very low speed presents several difficulties due to the nonlinear dynamics of the vehicle. Therefore, precise motion control relies on a good understanding of the vehicle response in correspondence with the input thrust of thrusters. This study developed a measurement system capable of measuring the thrust performance of a thruster. The thrust measurement system utilizes the lever principle to magnify output force and consequently increase the thrust measurement resolution. A voltage meter and a current meter are coupled to a power supply to continuously measure the voltage and current input to the thruster. The thrust measurement error resulting for friction and poor stiffness of the lever is significant. The thrust measuremnt is also disturbed by the electromagnetic interference from the thruster. Therefore, the stiffness of the lever is improved and a static preload is applied on the lever to reduce the error in thrust measurement. In addition, proper system grounding and optical isolation are designed in the measurement system for reducing electromagnetic interference in thrust measurement. To control the thruster by the ROV general purpose controller developed by the Institute of Undersea Technology, National Sun Yat-sen University, this study developed a DC motor controller. The motor controller includes a L298n motor driver and uses an ultra low power MSP430 microprocessor to control the speed and direction of a thruster. The performance of three commercial thrusters were tested by the thrust measurment system with different motor drivers. The measurement results of the thruster performance are in agreement with the data obtained from the thruster data sheets, which verifies the measurement accuracy and reliability of the thrust measurement system.