SHIP SPEED DETECTING DEVICE

• Main Authors: YOSHIOKA TATSUYA, SAWADA RYOJI, NAKAMURA TOMOJI, NAKAMURA KAZUHIRO
• Format: Patent
• Language: English
• Published: 27.01.1989
• Subjects: INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT; MEASURING; MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION,OR SHOCK; PHYSICS; TESTING

PURPOSE:To eliminate the influence of the atmospheric pressure being different due to a meteorological condition and altitude, etc., by calculating a ship speed, based on a difference between pressure applied to a semiconductor pressure sensor at the time of stop, and pressure applied to the semiconductor pressure sensor at the time of movement. CONSTITUTION:A reference value setting means 4 stores pressure applied to an opening 35 at the time when a ship is stopped, as a reference value. A speed operating means 5 inputs a digital voltage signal from an ADC 2, and first of all, subtracts said reference value from its value. The value which has been derived in such a way corresponds to a pressure value obtained by subtracting the atmospheric pressure from the pressure applied to the opening 35, namely, dynamic pressure generated due to a movement of the ship, and subsequently, a speed operating means 5 calculates a vessel speed from this value. In such a way, only a value corresponding to the dynamic pressure based on the movement of the vessel can be fetched purely, and an exact ship speed can be derived.