This paper described the method and the result of making a dynamic fiber optic gyrocompass measuring the heading angles of ships by processing the output signal from a constant rotating fiber optic sensor and also showed the measurement to test the performance of our system. Considerig an economical view we designed and ordered a cheap medium grade fiber densors increased not fiber length but the diameter of a fiber sensing loop. The scale factor and noise was 267mV/deg/s and 2 deg/hr/Hz(1Σ), respectively. We made the dynamic fiber optic gyrocompass by this sensor. We measured the heading angles in an arbitrary direction to evaluate the accuracy of our system and the root mean square error was 0.4˚. Moreover, we measured the angles ineach direction of 45˚. successive rotation to know whether this system has distoritions in a specific direction or not and the root mean square error in this case was 0.5˚.

This paper describe the method and the result of making a fiber optic gyrocompass measuring the heading angles of a ship with a fiber optic sensor. As the method seeking for the heading angles, it is possible to get the heading angles by measuring the output signals from a stationary fiber optic sensor in at least three directions such as a heading direction and other two directions having phase difference Φ1 and Φ2 to the heading. We made the static fiber optic gyrocompass by a high performance fiber optic sensor having scale factor of 210mV/deg/s and resolution of 0.5deg/hr using this principle. The accuracy of this system was 0.29˚ from 20 numbers of data measuring the arbitrary heading angle.

In this study, an interface is developed in compliance with the standards which is made by National M.E.A in U.S.A for transmitting the Marine Gyrocompass information. The interface consists of Bearing Signal Transfer, Bearing Signal Demodulator, Bearing Signal Discriminator, Bearing Counter and, Informatioin Tranmitter. The results are as follows : The transmission of bearing information was achieved successfully on the Marine RADAR by the interface tranmitting for the Marine Gyrocompass. And, newly proposed phase-detector in Bearing Signal Discriminator which method is forcibly reset the previous data of D-T Flip Flop can be solved the problems of the delay in phase discrimination and the unstableness in the boundary areas of input signal.

In this study, the self test-system for the marine Gyrocompass was developed and the obtained results are summarized as follows : 1) Utilizing the newly developed self-test system, the time length for observing the transient state of Gyrocompass reading which has been over 4 hours can be reduced to less than 20 minutes. In addition, the dynamic characteristics of the Gyrocompass can be measured within 2 hours after starting the system. 2) Prior test and diagnosis was done by checking all parameters recurrently with period of 2.5minutes. 3) Testing and diagnosis results was shown in graphic mode and could be transmitted to INMARSAT unit using personal computer. 4) The results of the newly designed trouble algorithm for the system was found to be applicable under arbitrary given conditions.

As a basic study for enhancing the sensitivity of the follow-up system of the marine gyrocompass, the geometric characteristics of the deflection sensor were investigated and the theoretical model of it was formulated. The output signal voltage of the deflection sensor was esamined by changing the attitude of gyrosphere against follow-up container. The characteristics of the output are found to be indentical with those of the distance difference versus the relative azimuthal deflection of the gyrosphere against the follow up container. On the base of the theoretical model, some useful points for the design of the deflection sensor are suggested as following : 1. When the difference between semidiamter of gyrophere and that of the follow-up container decreases, the sensitivity of deflection sensor increases. 2. If the semidiameter difference of two spheres is constant, the sensitivity of deflection sensor is proportional to the magnitude of the semidiamter of each sphere. 3. The farther the gyrosphere is deviated from the center of follow-up container, the higher the sensitivity of deflection sensor is. 4. It is recommendable that the value of the datum deflection of the electrodes on the gyrosphere should be within the range between 4˚ and 16˚deviated from north-south line.

One of the main purposes of the marine gyrocompass follow-up system is to preserve the sensitive part from the wandering error due to the frictional or torsional torque around the vertical axis. This error can be diminished through the rapid follow-up action, which minimizes the relative azimuthal angular displacement between the sensitive and follow-up parts and shortens the duration of the same displacement. But an excessive rapidity of the follow-up action would result in a sustained oscillation to the system. Therefore, to design a new type of the follow-up system, the theoretical annlysis of the problems concerned should be studied systematically by introducing the control theory. This paper suggest a concrete procedure for the optimal adjustment of the gyrocompass follow-up system, utilizing the mathematic model and the stability informations formerly investiaged by the author. For theoptimal determination of the adjustable paramfter K, the performance index(P.I.), ITSE(Intergral of the Time multiplied by the Squared Error) is proposed, namely, P.I. = ʃ0∞ t · e2(t)dt where t is time and e(t) means control error. Then, the optimal parameter minimizing the performance index is calculated by means of Parseval's theorem and numerical computation, and the validity of the obtained optimal value of the parameter Ka is examined and confirmed through the simulations and experiments. By using, the proposed method, the optimal adjustment can be performed deterministically. But, this can not be expected in the conventional frequency domain analysis. While the Mps of the original system vary to the extent of from 0.98 to 46.27, Mp of the optimal system is evaluated as 1.1 which satisfies the generally accepted frequency domain specification.