Ship speed measurer without water resistance

Abstract

An instrument for measuring ship speed without water resistance is composed of an acceleration sensor set consisting of primary sensor and compensating sensor, a signal processing circuit, and a microprocessor. Its advantages are high correctness and high stability. The primary sensor has its sensing direction mounted in the advancing direction and the compensating sensor in the direction perpendicular to advancing so that the invented instrument can realize the measurement of non-resistance and multi degree of freedom for understanding and analyzing ship motion state. It can also be used to measure the multiple states of paddle operation.

Description

technical field [0001] The invention relates to a measuring instrument for measuring the speed of a boat, in particular to a measuring instrument for measuring the speed of a boat during rowing. Background technique [0002] Regarding the method and device used for ship speed measurement, U.S. Patent No. 5,597,952 "Speed ​​Measurement and Compensation Device for Jet-Propelled Ships" uses pitot tubes and pressure sensors to measure, and the sensitivity is poor when measuring low ship speed; the applicant participated in The Chinese patent "Measuring Instrument for Vessel Speed ​​and Oars Frequency" (Patent No.: ZL95212125.5) uses electromagnetic sensors and semiconductor piezoresistive sensors. In the water, the resistance of the ship is increased; U.S. Patent No. 5483242 "Method for Measuring the Speed ​​and Distance of Objects" uses electromagnetic waves to measure; The device of speed of moving object " all is to utilize the Doppler effect of sound wave to carry out the m...

AI Technical Summary

Problems solved by technology

Due to the installation of additional equipment below the waterline of the hull, the generation of water resistance cannot be avoided, and sometimes it will cause yaw, the measurement results cannot fully reflect the situation in real competition, and it will have a negative impact on the rower’s action training, thus limiting scope of application

[0004] The applicant participated in the design of the Chinese patent "Non-water resistance ship speed oar frequency measuring instrument" (Patent No.: ZL98235770.2), which uses an acceleration sensor to measure the acceleration of the hull in the forward direction, and integrates the acceleration. Realize the measurement of boat speed and oar frequency without water resistance, but if the boat is severely bumped due to strong wind and waves or poor rower skills, the measurement results will contain additional errors

[0005] U.S. Patent No. 20020002863 "Speedometer" is to measure the acceleration of the human body in two or three main directions when it is moving, and then integrate the acceleration to make a human walking speedometer; U.S. Patent No. 20010034583 "Athlete Speedometer" , is to use the main acceleration sensor and the compensation acceleration sensor to measure the speed of skiers, ice skaters and mountain bikers; the above two patents do not involve the measurement of boat speed

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