Theoretical Analysis of the Bearing Faults Impact on Large Aperture Antenna Pointing Accuracy

The reflector antenna has been widely used in the deep space exploration, radar warning and so on, which are all in a urgent demand for high pointing accuracy. The performance degradation and structural damage of the key antenna components can severely deteriorate its electromagnetic performance, resulting in the deviation in antenna pointing and its stability during operation. This issue becomes one of the bottlenecks that restrict the antenna performance assurance and further improvement of the large aperture antenna. Therefore, this paper aims to reveal the underlying relationship between the different bearing health conditions and the antenna pointing accuracy. Based on the spherical Cartesian coordinate system, a mathematical relationship has been established for the angle errors in the antenna azimuth and pitch directions, based on which, a dynamic model of the antenna transmission system has been established. By establishing a bearing distribution fault model, a local fault model, and a wear fault model; Exploring the changing trend of bearing fault types on shafting errors, and quantitatively analyzed the changing trend of pointing accuracy under different faults. The results indicate that under the state of load, bearing faults have a significant impact on the radial oscillation error of the pitch bearing, thereby causing changes in angular error.