Design And Research For High Precision Large Scale Diameter Shaft Angle Measuring And Control System

The technology’s development of aviation, aerospace and other industrial areas is an important basis to measure the science and technology strength, economic strength and national defense power of a country. The development of all kinds of aero & space vehicles is inseparable from the turntable. Along with the advance of science and technology, the continuous improvement of productivity, we need to improve the dynamic performance and the accuracy of the turntable. Large scale diameter shaft angle measuring system is widely used in large sizes of radar, seeker simulation equipment.In large size seeker, radar simulation equipment, the inner ring is hollow, so large scale and high precision angle sensor is needed. The circular gratings’ diameter is always small, so it cannot be applied to large sizes of radar simulation equipment. It is discussed to improve the accuracy of large scale diameter shaft angle measuring system and improve lowspeed stability of the turntable.In the design of high precision large scale diameter shaft angle measuring system,using linear gratings to realize large scale diameter shaft angular measurement, using the installation structure of four reading heads evenly distributed, to solve the problem of joint data processing, eccentricity error and axis’ rotating error. In order to improve angle measuring accuracy further, we get the experimental data by 23-sided polygon and autocollimator, and compensate for angle measurement error through the software method of harmonic compensation. This compensation method is validated by Matlab simulation.In the design and research of high precision turntable control system, the mathematical model of the turntable motor system is established and motor system parameters is given, based on the characteristics of motor system a turntable controllor was adopted.It’s verified that the dynamic performance of the turntable can meet the requirements.Through the analysis of the low speed tracking performance of the turntable control system we can know that to reduce the low speed crawl, on the one hand, we need to reduce the ratio of the dynamic and static friction, on the other hand to increase the damping of the system. It is verified by the simulation that the friction torque interferenceon has a harmful effect to the turntable on the performance at low speed.In the study of the interference and compensation of friction torque, in order to reduce the influence of friction torque on the turntable low-speed performance, we designed an adaptive friction compensation method based on LuGre friction model, it isverified by the simulation that this method can eliminate system low speed crawl phenomenon and improve the performance at low speed.