Development Of The Rotation System For Log Calibration

As one of the most important navigation instruments, log is used to test the ship's speed .It is necessary to do log calibration in the course of developing log. What the thesis studies is about a new rotation system for log calibration. The system is composed of rotation institute, driver system, control system and examination system. According to the requirements, the system configuration has been finished.The control system's design is introduced in detail because of its important role in the rotation system. After analyzing a number of common digital PID control methods, the Position control method is used to achieve speed control precisely, and the integration separation control method is used to achieve position calibration. The influence on the system performance by the sample time interval is also discussed.The mechanism of several soft timers in the Windows and the hardware timer in pcl-833 are introduced. In order to achieve the precision request of control system, the internal timer on the counter board is used to lock the counter precisely, and the multimedia timer in the window's system is used for sampling and controlling. In addition, bitmap button and double–buffering technology are used to draw a friendly interface.Finally, the experiment of the system has been introduced. The result of testing data indicates that the system is feasible and shows that the display precision reaches 1‰FS and the control precision reaches 2‰FS.