###### Abstract
Research has been conducted on six-degree-of-freedom measurements based on the guidance system used in shield machines, including the Huazhong University of Science and Technology [14; 15], which investigated the use of high-resolution CCDs to improve the positioning accuracy of the center of the spot and effectively improve the measurement accuracy of the shield attitude angle. Zhengzhou University [16], based on the kinematic model of the equivalent mechanism, used a hybrid neural network-Newton algorithm to solve the shield position and found that the accuracy of the shield tunneling position control was improved. The error value of the prediction using a single neural network is up to 30 mm, and the error value using the hybrid neural network-Newton iterative algorithm is stabilized around 1 \(\times\) 10\({}^{-5}\) mm. [PERSON] [17] from Tangshan College developed a laser-guiding target for shield machines. The shield guiding system is mainly composed of a total station, a reference prism, and a laser target [18], employing a CCD camera, tilt sensor, and prism to accurately determine the shield's attitude angle and position coordinates. The system has a simple structure, easy calculation, as well as higher accuracy. In the system mentioned above, the laser target is mainly composed of a pinhole prism, an inclinometer, and a CCD industrial camera. This method has the advantages of simple operation, large measurement range, good portability, real-time measurement, and strong environmental adaptability, but it has the problems of low measurement update rate and slow response. Additionally, to ensure measurement accuracy, the inclinometer requires a certain range of measurement angles, which significantly restricts the system's angle measurement range, particularly the roll angle [19; 20]. [PERSON] from Hubei University of Technology [21] conducted a study on monocular visual attitude measurement methods, where feature points on the cooperative target were captured using a CCD camera to complete the attitude angle measurement and the measurement accuracy was evaluated using a high-precision two-dimensional turntable. [PERSON], [PERSON]; [PERSON], [PERSON] [22] posed measurement method based on 2 DPSD and monocular vision is proposed, and the SVD method is used to calculate the relative attitude between the laser tracker coordinate system and the camera coordinate system. This method can control the maximum error of attitude angle measurement to be less than 2\({}^{\circ}\) within the effective angle range of [\(-25^{\circ},25^{\circ}\)] and at a distance range of 3 m. [PERSON] [23] proposed a laser-tracking attitude measurement method that combines a PSD with monocular vision. This method overcomes the issues of a slow update rate for the roll angle and limited measurement range, showing good measurement performance over long distances. Compared to traditional methods, such as the POSIT algorithm, the accuracy of both azimuth and elevation angles has been improved by more than 75%. To further improve the measurement accuracy of vision, [PERSON] and [PERSON] [24] proposed a method for pose calculation based on the WAOI algorithm. This algorithm uses the OI algorithm as its core to solve visual measurements. Within an angular measurement range of \(-20^{\circ}\) to \(20^{\circ}\) and a measurement distance of 3 to 15 m, the accuracy of the azimuth and elevation angles of the laser tracking measurement system using the WAOI algorithm can be better than \(0.26^{\circ}\). Compared to the POSIT algorithm, the accuracy of both azimuth and elevation angles has been improved by more than 75%. However, there is still considerable room for improvement in terms of system measurement accuracy and dynamic performance [25]. Tianjin University [26; 27; 28; 29; 30] proposed a six-degree-of-freedom measurement method based on a laser tracker and inertial navigation. An FKF based on the residual chi-square test is proposed in order to solve the fatal problem of inclinometer failure under dynamic conditions.