Research on attitude measurement technology of north finder in underground coal mines

North finder is a kind of high precision inertial instrument which can point north rapidly. It is based on the horizontal component of earth rotation rate measured by gyroscope and the error angle of gyroscope axial horizontal tilt measured by accelerometer. After solving, the Angle between the reference axis and the true north direction is obtained, and the angle between a fixed axis and the north direction of the carrier is obtained.

Background

Coal is one of the important basic energy resources in our country. With the increasing of mining depth and difficulty, the safety mining of coal mine is becoming more and more important. Gas and water damage is the most important disaster in the process of coal mining and control, and drilling technology is one of the main means to control and detect gas and water damage in coal mines. This paper adopts one of MEMS north finder and realizes attitude measurement function suitable for coal mine. It can be static all-weather, all-round, autonomous, rapid determination of orientation and attitude.

At present, in the process of coal mining and gas extraction in China, most of the mechanical compass and electronic compass are used to measure the azimuth angle. Due to the special environment under the mine, the compass is susceptible to the interference of the surrounding electromagnetic field. Although the azimuth and attitude measurement technology of the electromechanical gyroscope is mature, with small drift and high precision, the electromechanical gyroscope has defects in environmental adaptability. Such as poor vibration resistance, low temperature work limited, high cost, high energy consumption. With the development of inertial navigation technology, inertial north finder has been widely used in military and civil orientation.

Attitude measurement function of the north finder

The MEMS north finder is an important part of the borehole orientation finder scheme, which provides the azimuth reference for the whole scheme, and its north finding accuracy determines the overall accuracy of the scheme. In order to obtain the attitude Angle accurately, it is necessary to obtain the attitude angle by solving the attitude updating algorithm. The results of attitude updating technology are widely used in aerospace, industrial robot and other fields. With the demand of consumer market in recent years, attitude measurement technology has been applied in automotive electronics, wearable devices and other fields. The attitude measurement technology is to calculate the attitude information in real time in the controller and express it in the form of matrix or angle. The attitude measurement technology is realized by attitude updating algorithm in software, and angle increment information is obtained by angle rate sensor in hardware. The angle rate sensor and the attitude updating algorithm are important factors affecting the updating speed and accuracy of the attitude angle information.

Whether to reach the target of exploration according to the pre-designed trajectory is the main criterion for the success of drilling technology. The measuring equipment for drilling trajectory came into being and developed rapidly. However, the research and application of drilling hole positioning equipment have been less. In recent years, many scholars and units have conducted research on drilling hole positioning equipment, but the measurement accuracy, cost and operability still can not meet the actual needs.

This time, Ericco company launched a new north seeker ER-MNS-09, different from the general low and medium precision north finder directional equipment, the performance and parameters of this north seeker are better than the traditional MEMS north seeker system, the use of high-precision MEMS gyroscope for north operation, get the initial reference of tilt Angle and azimuth angle. For the azimuth measurement, the magnetic sensor-based inertial measurement method applied to the borehole trajectory attitude measurement cannot be used because of the interference of ferromagnetic materials. Therefore, based on the initial attitude value, the combination of three-axis MEMS gyro and three-axis accelerometer is used to track the attitude, and the velocity and position parameters of the carrier are obtained by solving.

Summary

In this paper, the MEMS north seeker is discussed in detail, and the three-axis MEMS gyro is used to design and realize a north seeking orientation attitude measuring instrument suitable for coal mine. It can measure orientation and attitude in static all-weather, all-round, autonomous and fast, and provide a new positioning equipment for the measurement of attitude angles of mining equipment. If you are interested, please feel free to contact us, as well as the cost-effective MEMS north finder ER-MNS-05, the world's smallest MEMS north finder ER-MNS-06 and so on.