一种利用磁信标准确导航定位的方法

Aiming to solve the problem that lacking of reliable positioning source, an accurate navigation and positioning method based on artificial magnetic beacon. Related investigations have shown that the low-frequency magnetic field performs good penetrability and robustness in near magnetic field area. Therefore, based on the advantages of the low-frequency magnetic field, a novel solution to solve the position and the attitude is introduced. According to the Biot-Savart Law, the magnetic field intensity decays with the distance between the target and the magnetic source, and the orientation of measured magnetic field has the certain relation to orientation from the source to the target. Hence, based on this principle, an improved fingerprint algorithm is introduced. Firstly, the fingerprint is blocked according to distance. Then, the fitting curve reflecting magnetic field intensity and the distance to the magnetic source is computed of each block. Based on this improvement, the weight of each fingerprint can be computed more accurate than the usual. Furthermore, according the vectors, which contains the measured magnetic field vector and orientation vector point from the magnetic source to the target, the attitude related to the magnetic source can be solved, too. Comparing the traditional methods, the advantages of the proposed one are high accuracy, and no requirement on the consistent coordinates between the magnetic beacons and receiver. The artificial magnetic field generated by the magnetic beacon can be extracted accurately from the natural magnetic field in the applying environment. The precision on position and attitude can reach to 0.069m and 2.3°, respectively, in the static target tracking experiments. What is more, the experiment also presents that the estimated error is not accumulated with the increased working time. In the experiments, the model of magnetic beacon is the quadrature solenoids. This model is limited by the quality factor of the model. Therefore, it is hard to this model having large coverage and high working frequency. But this model is only to verify the proposed positioning method. Actually, the magnetic beacon can be replaced by rotary permanent magnet which having large coverage and the same positioning process proposed in this paper. According to the result, it shows the proposed method can provide long-time, highly accurate, and harsh environments navigation. The proposed method is significant to the long wavelength positioning and remote sensing technology in the underground, under water and other harsh environments.