Structure Design And Alignment Error Analysis Of The Antenna Test Turntable

The antenna test turntable is a kind of important simulation test device which is useful for completing the task of the antenna measurement in a far-field region. The antenna’s pitching, yaw, roll and other motion can be simulated by the turntables. It is widely used in the aerospace, the communication technology and scientific research area. In the test system, the alignment of the transmitter and receiver turntable play a very important role on the antenna signal alignment. The performance of the test turntable is directly related to the accuracy of the simulation and experimental results which is the basis of ensuring accuracy and performance of antenna. In this paper, according to the turntable technical requirements, complete mechanical structure design of the antenna test turntable and establish the error modeling.Firstly, This paper focuses on the structure design and dynamics analysis of the antenna test turntable. According to the technical requirements, finish the overall structure design including the selection of drive components,drive modes,angle and displacement measurement units,the control of speed precision and the exploration of processing methods of key components. Based on FEA,the structural strength,rigidity and deformation is verified.Secondly, according to the Workbench,the antenna test turntable is optimised,including topology optimization of the nylon part and the optimization of the U frame of the receiving part. The driver optimization can realize the design of multiple objective function and more complex arithmatic at the same time. Additionally, an optimum plan for the antenna test turntable is obtained that the stability and accuracy of the turntable is guaranteed.A kind of better material removal scheme is protocoled through the topology optimization.Thirdly, an error model of the antenna test turntable is established. According to the structure and working principle of the antenna test turntable,the aliment error of the antenna turntable is described by multi-body system dynamics theory, including the linear error and angular error of the turntable output axis relative to the benchmark. The error model of the system is simulated by Matlab. The influence of each error source on the alignment error of the turntable is analyzed,respectively. The testing methods for alignment error of the turntable are discussed finally.