Research Of Test Methods For Friction Torque

Friction torque will cause fluctuation and deviation when precision instrumentation systems are running. In addition, it is also an important evaluation indicator for dynamic performance of shaft. Therefore, that qualitative and quantitative understanding for friction torque of the shaft is very valuable for the inertial navigation system to improve the accuracy and dynamic performance. At present, there is still no automation equipment for precise measurement of friction torque of shaft. Generally, we measure friction torque of every part before installed, and then estimate the total friction torque. As increasingly high demand for technical parameters, especially the precision shaft parameters of military products, it is necessary to do theoretical analysis for friction and the friction torque and also do research for test methods.This paper, according to the macro-theoretical analysis of friction, especially sliding friction and rolling friction, analyzes and summarizes the factors and describes the compensation and control methods of the friction torque, and then on the basis of an analysis of domestic and international test methods of friction torque, proposes a test method based on the virtual instrument and two specific test prpgrams, of which the methods of angle and speed measurement based on the resolver and the rotary encoder, and the methods of torque measurement based on the output torque characteristic curve of motor and the torque sensor are researched and compared, and the motor-driven methods and PID algorithm are analyzed in details, finally, according to the test method based on the virtual instrument, builds a torque testing experimental system based on NI PXI-1042Q chassis, NI PXI-6251 data acquisition card, low-speed AC motor, optical encoder and torque sensor, and designs the software of the system based on LabVIEW and NI DAQmx for a partial verification for the test method, and the verification gets satisfactory results.