Abstract
It is of significant importance to monitor the attitude of ship during navigation and operations. The three uppermost parameters of the attitude monitoring are roll, pitch and heave. For measuring the above parameters accurately, a sensor is designed in this paper. First, the attitude algorithm of this sensor is learned. A modified Rodrigues parametrisation-based method is developed in solving the attitude algorithm and extended Kalman filter algorithm is used to achieve the optimal value. The sensor calibration model was studied too. Second, in order to observe and measure the results more conveniently and intuitively, a user-friendly monitoring system is developed. Due to the development of the corresponding analysis system, the measured results can be analysed for a better understanding of the characteristics of the ship. Specially, the ship command parameters are as the input of the sensor and the corresponding closed-loop measure, and control system is designed to solve the problem that the current study cannot eliminate the effects of the attitude measurement inaccuracy of the sensor very well owing to the ship's acceleration. The control strategy is verified by the sea trials because the attitude measurement error caused by the ship's acceleration is significantly reduced. The accuracy of the designed attitude sensor is also verified. More importantly, the application prospects of the designed are also illustrated in this paper.
Acknowledgements
The authors are grateful for the technical support from the Sentera Technology Corporation.