The Structure and Application of FOG North Seeker in Mining

North seeking technology is mainly divided into gyroscopic north seeking and non-gyroscopic north seeking in terms of equipment used; In terms of the selected methods, they mainly include inertial method, astronomical observation method, geodesy method, satellite positioning method. There are many methods of finding north such as reference object method.

However, in tunnels, underwater and other complex terrains and complex weather conditions, astronomical observation methods, geodesy methods, satellite positioning methods and reference object methods will be restricted to varying degrees, or have low accuracy, or cannot be implemented at all. Only the inertial method can independently complete the north-finding task without being disturbed by natural conditions or the environment. It has the characteristics of long continuous working time and high accuracy, so it is the most commonly used.

The concept of north seeker:

The north seeker is an important development in inertial technology. As an independent azimuth indicating inertial product, the strapdown north seeker can quickly, accurately and all-weather determine the north direction. It has broad application prospects in both military and civilian fields. .

Internal structure of the north seeker:

ER-FNS-03 low-cost three-axis FOG north seeker uses a closed-loop fiber optic gyroscope as the core component. It is mainly composed of an inertial measurement unit (IMU), a digital signal processing unit and a mechanical part. Provides true north azimuth for the carrier.

Gyroscopes measure the angular velocity of the Earth's rotation, and accelerometers measure linear acceleration. The device collects the gyro force feedback loop current and the output of the accelerometer. The digital quantity converted by A/D is processed by digital filtering to calculate the attitude angle of the carrier and obtain the angle between the carrier and the geographical north direction to complete the orientation.

Application in coal mine field:

Our country's demand for coal mines is increasing year by year. In order to ensure energy supply, coal mines in various provinces and cities continue to expand production, and coal production tasks are arduous. Heavy mining work will lead to a serious situation of coal production safety, and serious accidents, especially gas accidents, occur from time to time. The main measure to prevent and control coal mine gas accidents is borehole drainage. Parameters such as azimuth angle have a decisive impact on the gas control effect. Once the borehole deviates from the predetermined direction, it will lead to the existence of a blank zone of undrained gas in the coal seam, which will affect the subsequent mining operations. to safety hazards. Therefore, the accuracy and rapid acquisition of azimuth angles of coal mine drilling rigs when working underground are crucial to safe production.

The north azimuth angle is an important attitude angle reference datum for the drilling rig, and being able to quickly seek north is an important parameter for achieving precise operation of the drilling rig. The north-seeking instrument calculates the northward azimuth angle of the drilling rig through the sensitive earth rotation component of the fiber optic gyroscope. The north-seeking algorithm directly affects the north-seeking accuracy and speed. This has higher requirements in terms of north seeking accuracy and north seeking time. The accuracy of the low-cost three-axis FOG north finder is between 0.25°secψ-1°secψ （°，5min）and the north seeking time is 300s, which is particularly suitable for mining industry applications.

With the development of science and technology, the application fields of north seekers are constantly expanding. Whether in tunnel construction or ground survey, radar antennas have broad development prospects. This has also made people's requirements for north seeking device higher and higher. According to people's different application environments, portable north finders have also been derived, which are small in size and low in energy consumption, meeting the needs of some customers who have requirements for product size. In addition, some north seekers can also cope with harsh monitoring environments. For details, please see the detailed introduction of MEMS north seekers. The subsequent integration of north finding device with other technologies will further promote the equipments' development.

If you want to know more about the North Finder, you can click on the link below to view the details.