Tokimec Inc.

Kabushikikaisha Tokyo Keiki

Fuyuki Hane

Takeshi Hojo

Shinichi Kawada

Kazushige Murabayashi

Mamoru Akimoto

Michio Fukano

Kanshi Yamamoto

Kazuteru Sato

Shin-ichi Kawada

Youji Okamura

Masahiko Saito

A gyro compass having a gyro case housing therein a gyro and supported with freedom of three axes, functions for outputting a signal corresponding to an inclined angle of the gyro spin axis relative to the horizontal plane, and a function for applying a torque around a vertical axis of the gyro case in proportion to an input signal. A controller is supplied with a signal corresponding to the inclined angle and a latitude value at which the gyro compass is located, and a constant relative to the input latitude value is determined by the controller after the gyro compass is energized. A signal, resulting from differentiating the signal corresponding to the inclined angle during a predetermined time, is added to the product of the signal corresponding to the inclined angle and the constant. This added signal functions as the input signal for the gyro, whereby a constant optimum north-seeking movement is carried out regardless of the change of the latitude value. An error corrector is provided having supplied to it the signal corresponding to the inclined angle, the speed signal of the vehicle and its heading azimuth signal, and a bias error caused by the inclined angle of the gyro compass spin axis and an azimuth error caused by the movement of the vehicle are estimated and calculated to thereby reduce an azimuth error caused by any bias error and the vehicles' movement.

Gyro compass

A gyro compass having a gyro case housing therein a gyro and supported with freedom of three axes, functions for outputting a signal corresponding to an inclined angle of the gyro spin axis relative to the horizontal plane and a function for applying a torque around a vertical axis of the gyro case in proportion to an input signal, and a controller supplied with the signal corresponding to the inclined angle and a latitude value at which the gyro compass is located, wherein a constant relative to the input latitude value is set by the controller after the gyro compass is energized, a signal, which results from differentiating the signal corresponding to the inclined angle during a predetermined time, is added to a signal, which results from multiplying the signal corresponding to the inclined angle with the constant and an added result is set as the input signal, whereby a constant optimum north-seeking movement is carried out regardless of the change of the latitude value to thereby reduce a settle time. Also, the gyro compass having an error corrector supplied with the signal corresponding to the inclined angle, a speed signal of a navigation vehicle and its heading azimuth signal, wherein a bias error caused by the inclined angle of the gyro compass spin axis and an azimuth error caused by the movement of the navigation vehicle are estimated and calculated to thereby reduce an azimuth error caused by the bias error.

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.

Vibration-type gyro apparatus

Growing community of inventors

Tokyo, Japan

Fuyuki Hane