Grating Torque Meter Dynamic Measuring System

As the hydraulic turbine running under complex and tough environment, it is ofgreat importance to secure the safety of the main axis and to real-timely monitor theperformance of the axis. Under the sponsor of NSFC(National Natural ScienceFoundation of China), "the Research of Dynamic Characteristics of Hydraulic Turbine'sMain Axis Mechanical System"project employs the grating sensor to measure thetorque of the main axis real-timely and dynamically. The research and design of thesystem provide a novel and effective way to monitor the torque of the main axis.The article first introduces the development of torque sensors at present, analysesthe merits and demerits of the kinds of torque sensors. According to the workingenvironment and the merits of grating sensor, the grating sensor is adopted as the signalsensitive component in torque measuring of hydraulic turbine.The article analyzes the output signal influenced by the running state, therelationship between the phase of the two signals and the torque angular, and setups thesystem mathematic model and the computation formula. According to the model, it isobvious that the system is suitable for dynamic measurement compare to the staticmeasurement of the other differential measuring torque meters. The system,un-correlated with the amplitude of the optoelectronic signal, needn't to be calibratedand is easy to mount and to debug.The article discusses the composition of the dynamic measurement input data, andthe dynamic measurement data processing according to the characteristic oftime-variable, random, correlation and dynamic. The article explores the pre-processing,component attract and result presentation of the data. To reduce the random error, theparallel auto-adapt KF filter is adopted to process the real-time dynamic data.According to the mathematic model and the dynamic data processing solution, theC language program is programmed to secure the normal operation of the system andthe accuracy of the data processing. The system satisfies the requirement of real-timedynamic measurement.