###### Abstract  
Large-space high-precision attitude dynamic measurement technology has urgent application needs in large equipment manufacturing fields, such as aerospace, rail transportation, automobiles, and ships. In this paper, taking laser tracking equipment as the base station, a backpropagation algorithm based on neighborhood search is proposed, which is applied to the fusion of multi-source information for solving the dynamic attitude angle. This paper firstly established a mathematical model of laser tracking attitude dynamic measurement based on IMU and CCD multi-sensor, designed a 6-11-3 back propagation network structure and algorithm flow, and realized the prediction of attitude angle through model training. Secondly, the method based on neighborhood search realizes the determination of the optimal training target value of the model, of which the MSE has a 34% reduction compared to the IMU determination method. Finally, the experimental platform is set up with the precision rotary table as the motion carrier to verify the effectiveness of the research method in this paper. The experimental results show that with the neighborhood-based backpropagation algorithm, the measurement results have a higher data update rate and a certain inhibition effect on the error accumulation of IMU. The absolute value of the system angle error can be less than 0.4\({}^{\circ}\) within 8 m and 0-50\({}^{\circ}\), with an angle update rate of 100 Hz. The research method in this paper can be applied to the dynamic measurement of laser tracking attitude angles, which provides a new reference for the angle measurement method based on the fusion of multi-source information. laser tracking; attitude measurement; dynamic measurement; back propagation; neighborhood search; artificial neural network +
Footnote †: journal: Applied sciences  
0000-0001-5000-7999]Z.Z.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.X.Zi.X.Zi.X.X.Zi.X.X.Zi.X.Zi.X.X.Zi.X.Zi.X.X.Zi.X.Zi.X.X.Zi.X.X.Zi.X.Zi.X.Zi.X.Zi.X.X.Zi.X.Zi.X.Zi.X.Zi.X.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zi.X.Zmanufacturing, large-scale scientific engineering construction, and digital assembly [4; 5; 6]. The six-degree-of-freedom measurement method based on laser tracking equipment is a promising solution [7]. This system typically consists of laser tracking equipment, an upper computer, and cooperative targets, using laser technology to track and measure the pose information of moving targets [8]. It features high precision, a large measurement range, and on-site measurement capabilities, making it a core detection system for large high-end equipment manufacturing. This system is widely used in various industrial fields such as aviation, aerospace, automotive, shipbuilding, and manufacturing [9; 10]. The T-Mac Sensor system from Leica integrates laser tracking devices, high-speed cameras, and Mac target units. This system is capable of real-time online measurement and tracking, making it suitable for high-precision measurements in dynamic environments [11]. When used in conjunction with laser tracking devices, it can cover ranges from several meters to tens of meters while providing sub-millimeter measurement accuracy. However, due to its reliance on visual equipment, the system cannot perform continuous measurements when the field of view is obstructed [12]. On the other hand, the STS from API is another device designed for high-precision six-degree-of-freedom measurements [13]. Compared to the T-Mac, STS overcomes the limitation of interrupted measurements when the visual line is blocked, thereby adapting better to complex and variable measurement environments. Nonetheless, the use of inclinometers constrains its dynamic performance.