【作者】 钟美达；

【导师】 刘胜； 陈伟林；

【作者基本信息】 哈尔滨工程大学 ， 控制工程， 2008， 硕士

【摘要】 现代船舶对磁罗经影响所产生的自差常常很大,最大时航向偏差出现四五十度,甚至出现自差力完全削弱磁罗经指北力的现象,使磁罗经失去指北导航的意义。因此,国际航海协会作出规定:在新装磁罗经或磁罗经移位后、大中小修船后、磁罗经附近建筑物改建后、磁罗经发生剧烈振动后、船体经电焊或敲击出现自差显著变化的、船固定在一航向停泊一个月以上、船装运大量磁性货物后、没有用软铁消除软半圆自差力和感应自差力的罗经而航行纬度变化10°以上时、罗经校正自差后超过一年以上等条件下均需对磁罗经进行自差校正。同时由于传统自差校正方法需花费大量的人力物力和财力,对此新的磁罗经自差校正法成为各家追求的目标。舰用磁罗经校正系统正是智能化程度高、条件简单的磁罗经自差校正系统,其是一个综合电罗经技术和磁罗经技术的新的自差校正系统。本系统利用电罗经的自动测定技术来把电罗经航向信号数字化,设计实现航向数字化,利用本系统获得航向真值;磁航向信号通过磁阻传感器来直接敏感合成磁场,把磁航向信号数字化,设计实现数字磁罗经航向系统,输出被测的罗航向信号,获得罗航向;通过电罗经航向数字化系统和磁罗经航向数字系统获得真航向及罗航向,两者相比较求罗经自差。其原理为:磁阻传感器敏感外界磁场,输出罗航向直流感应电压信号,送至A/D转换器进行转换,并经单片机计算处理得到罗航向度数值;对同步电机或步进电机罗经的信号处理,对比信号的变化关系,利用单片机进行累加计算形成电罗经数字航向,将其数字航向作为系统的真航向;将其罗航向的数字航向和真航向(电罗经数字航向)对比,得到罗经差,去掉磁差,得到自差,并通过单片机计算得到五个自差系数,并求各个航向上的自差,以至实现单片机对罗经自差进行软件修正。本系统可以消除船舶倾斜时对船舶自差影响,实时显示船舶的罗航向、磁航向以及真航向;通过本系统的系统模拟仿真,结果与理论分析相符,实现最优设计。本系统与其他磁罗经校差方法相比较,电罗经对比法测量自差的本系统应更适合对于大中型船舶校正磁罗经自差。更多还原

【Abstract】 The deviation of magnetic compass was influenced by the modern ships mightily, which might appear fourty or fifty degrees, even the compass deviation completely weaken pointing north, or making it lose the capability of pointing northnavigate. Therefore, the international sail ARATS made the provision, The magnetic compass of the ship was measureing and correcting of compass under the conditions as follows: fixing, moving, changing the nearby buildings, taking place a violent vibration, ship body through electric welding, ship fixing at a direction anchor more than a month, ship transporting a great deal of magnetism goods, didn’t remove compass deviation with the soft iron after responding from it but sail latitude changed over ten degrees, and so on. Meanwhile, because the tradition method from compass correction needed cost a great deal of manpower, material resources and financial power, some new methods of compass correction were pursued by producers.Correct system of magnetic compass was an intelligence device under a simple condition, which was a new technic combinating the gyrocompassive technique and the magnetic compass. This system made use of auto measurement technique of electricity compass to turn numeral direction signal, design numeral direction system, make use of the originally system acquire the true value; Using magnetoresistive sensor to induct the environment magnetic field for compass course, the magnetic singal of course was numerical, the magnetic compass deviation automatic measurement and correction system synthesizes both gyrocompass and magnetic compass technique.This system utilized magnetoresistive sensor to induct the environment magnetic field for compass course, and got true course from gyrocompass, then compared compass course with true course in order to compute compass deviation. Its principle was that: the magnetoresistive sensor inducted the outside magnetic field, gived out the compass course signal to A/D and then the signal was transformed into digital signal, processed by SCM ,thus we might get the compass course; through the process of synchronous motror or stepping motor, we compared the change of signals, used the gyrocompass numerical course calculated by SCM as the real time true course; we then compasred 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 got five deviation coefficients and calculate the deviation each course in order to make SCM to correct the compass calculate the deviation each course in order to make SCM to correct the compass deviation software gyrocompass. Through a series of research, expersistive sensor was less than 0.5°,and after the measurement and correction of compass deviation through gyrocompass,thd signal error emitted by magnetoresistive magnetic compass is about l°.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 measureent and correction of those large or medium_size ships.更多还原