The Magnetic Compass Deviation Automatic Measurement And Correction System Based On The Gyrocompass Technique

Based on the gyrocompass technique, the magnetic compass deviation automatic measurement and correction system synthesizes both gyrocompass and magnetic compass technique. This system utilizes magnetoresistive sensor to induct the environment magnetic field for compass course, and get true course from gyrocompass , then compare compass course with true course in order to compass deviation. Its principle is that: the magnetoresistive sensor inducts the outside magnetic field, emits the compass course signal to A/D and then the signal is transformed into digital signal, processed by SCM, thus we may get the compass course; through the process of synchronous motor or stepping motor, we compare the change of signals, use the gyrocompass numerical course calculated by SCM as the real-time true course; we then compare the numerical and real-time true course (gyrocompass numerical compass), to get the compass deviation, and subtract gyrocompass course to get the deviation; through the calculation of SCM, we know 5 deviation coefficients and calculate the deviation each course in order to make SCM to correct the compass deviation software gyrocompass. Through a series of research, experiment and text, the result indicates that.the course error emitted by magnetoresistive sensor is less than 0.5 , and after the measurement and correction of compass deviation through gyrocompass, the signal error emitted by magnetoresistive magnetic compass is about 1 . This system may also remove the influence on ship deviation caused by ship inclining, showing the real-time compass course, magnetic course and true course meanwhile this paper also make a comparison with other magnetic compass technique and the corresponding ways of measuring and correcting, thus reach a conclusion that gyrocompass comparison way of measuring deviation is specially appropriate for the deviation measurement and correction of those large or medium-sized ships. Finally, this paper analyses the error system and its faults and proposes a tentative improvement program.