Abstract: To provide a gyro compass for the use of a high speed ship, in a gyro compass of the type having north-seeking means which is applied to support a gyro sphere or gyro case immersed in a liquid in a tank, a substantially first-order lag filter is provided in an azimuth follow-up loop or a damping loop, the substantially first-order lag filter having a time constant T.sub.F which is approximately equal to a ratio C/k.sub.T of the viscosity torque coefficient C to the twisting torque coefficient k.sub.T of the torque produced between the tank and the gyro case. A speed error correcting means has a substantially first-order lag filter having a time constant which is approximately equal to that of the north-seeking means, and is applied to correct the output of azimuth indicator by a speed error correcting angle through the substantially first-order lag filter.

Abstract: A fiber optic gyro can overcome the defects encountered with conventional fiber optic gyros of phase-modulation method, closed-loop system with serrodyne modulation and digital modulation. A reference phase difference .DELTA..beta. and a ramp phase difference .sigma. are generated in an interference light intensity signal I by use of a triangular waveform, i.e., delta serrodyne waveform signal. The reference phase difference .DELTA..beta. is changed to constant values .DELTA..beta..sub.A and .DELTA..beta..sub.B whose absolute values are the same and whose signs are different at every times T.sub.A and T.sub.B. A phase x of the interference light intensity signal I becomes equal to x=.DELTA..theta.+.sigma.+.DELTA..beta.. The ramp phase difference .sigma. is controlled so as to satisfy .DELTA..theta.+.sigma.=0. Accordingly, at the stable point of the control loop, a Sagnac phase difference .DELTA..theta. is equal to the ramp phase difference .sigma..

Abstract: An antenna having a central axis is supported on a supporting member which in turn is supported on an azimuth gimbal. The antenna and the supporting member are rotatable around an elevation axis perpendicular to the central axis gimbal is supported on a base and is rotatable around an azimuth axis perpendicular to the elevation axis. A first gyro having an input axis parallel to the elevation axis is secured to the supporting member, and a second gyro having an input axis perpendicular to both the central axis and the elevation angle axis is secured to the supporting member. An accelerometer is provided for outputting a signal representative of an inclination angle of the central axis relative to a horizontal plane. An azimuth transmitter is provided for outputting a signal representative of a rotation angle of the azimuth gimbal around the azimuth axis.

Abstract: A navigation apparatus utilizing a global positioning system having at least first and second satellite reception antennas installed on a navigation vehicle with a predetermined distance therebetween, a first azimuth computing unit for computing a first azimuth angle of the navigation vehicle from satellite radio waves received at the first and second antennas and a phase difference therebetween, a second azimuth computing unit for computing a second azimuth angle from a time change of antenna positions calculated from the satellite radio wave received at the first or second reception antenna, first and second multiplying units for multiplying outputs of the first and second azimuth computing units with predetermined coefficients respectively, an adding unit for adding outputs of the first and second multiplying units to produce a third azimuth angle, and a coefficient control unit for varying coefficient values of the first and second multiplying units in accordance with either the satellite arrangement or t

Abstract: A gyro compass having a gyro case incorporating a gyro of which the spin axis is substantially horizontal, a vertical ring disposed around the outer periphery of the gyro case and for rotatably supporting the gyro case around a vertical axis, a follow-up pickup for detecting an angular displacement between the gyro case and the vertical ring around the vertical axis, an accelerometer having an input axis parallel to the spin axis, a vertical torquer mounted on the vertical ring for applying a torque of magnitude proportional to an input signal to the gyro case around the vertical axis, and a control apparatus for receiving an output signal of the accelerometer and for supplying its output to the vertical torquer, in which during a predetermined time after the gyro compass is started to operate, the output signal from the accelerometer is differentiated to produce a differentiation signal which is then supplied to the vertical torquer to reduce a settling time of the north-seeking action.

Abstract: An attitude and heading reference detecting apparatus having three gyros and three acceleometers mounted to a navigation vehicle in such a manner that their input axes are made coincident with principal three axial directions of the navigation object, respectively, a magnetic azimuth sensor, a signal transforming section supplied with the outputs from the three gyros, the outputs from the three accelerometers and the output from the magnetic azimuth sensor, a computing section supplied with the output from the signal transforming section and a signal output section supplied with the output from the computing section, for producing an attitude and heading reference signal and for delivering the same to the outside.

Abstract: A marine automatic steering apparatus in which a part or whole of its control circuit is doubled as dual steering control sections same in construction includes a non-volatile memory controlled by either of the dual steering control sections and in and from which data can be written and read out.

Abstract: A vibration-type gyro apparatus is disclosed, which includes a vibration mass portion, a piezo-electric element for detecting the displacement of the apparatus and a preamplifier having an input resistance R and supplied with the output from the piezo-electric element, wherein the input resistance R is selected to have a value substantially expressed as R.apprxeq.1/C.omega. (where C is an electrostatic capacity of the piezo-electric element and .omega. is a vibration angular velocity of the mass portion) so that the gyro apparatus will be substantially free of variations due to temperature changes.

Abstract: The present invention relates to an automatic steering apparatus for ships which prevents the occurrence of directional instability due to unusual phenomena which occur at small rudder angles of so-called full-bodied ships.When the rudder angle of such ship is small, two stable steady turning conditions occur so that the turning movement cannot assume any single state and it results in a frequent and irregular unstable ship motion.