Experimental study on anti-roll controllers of a model boat

• Main Author: 葉逸軒
• Other Authors: 陳世樂
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/83486602207076522200

碩士 === 國立中正大學 === 機械系 === 89 === This thesis is to use a moving mass with suitable control law to reduce the rolling motion of a boat. A model boat is connected to a shaker through a mechanism. The shaker will generate periodic forces which simulate the wave forces. We establish a moving mass system under the hull. It is to use an AC servomotor with belt to move the mass from one side of the boat to another. In such a way, the boat’s center of mass can be adjusted to control its rolling motion. The mathematical model of the experimental system is derived by Lagrange’s method. In order to reduce the rolling motion, we design a linear state feedback controller by pole placement technique based on the linearized model. In addition to the linear controller, we also design a sliding mode controller to achieve better performance and robustness. The results of numerical simulations show that both linear and nonlinear controllers are effective in reducing the rolling motion. Since the nonlinear controller has better robustness, it will be used for actual application. In addition to theoretical analysis and numerical simulations, the designed controller is implemented in a PC-based controller using a DSP chip. Although the experimental results are not as good as those in numerical simulations, 50% of reduction in rolling motion is achieved by the sliding mode controller with the backstepping approach.