Research On Permanent Magnet Rotation(Angle) Acceleration Sensor And Torsional Vibration Signal Acquisition And Processing System

Mechanical rotation is the main form of modern mechanical equipment,and it has been widely used in chemical,aviation,electric power,military,automobile and other industries.Rotating machinery system is composed of prime mover,transmission mechanism and load,etc.When there is a torque difference between the output torque and the load torque of the prime mover,transmission mechanism is affected by mechanical accuracy,long-term running wear and operation failure,the shafting will produce vibration and noise.In engineering,in order to identify the operating conditions and faults of the rotating system,the usual practice is to measure the vibration and noise of the shafting of the rotating system.Improve the level of fault identification and fault diagnosis capability of rotating machinery system is great significance to improve the comprehensive operation level and efficiency of the mechanical rotating system.Nearly a century,many experts and scholars have done research on measurement of rotating shaft vibration,but there are many shortcomings,such as the research process is complex,mostly through indirect measurement,sensor measurement system is complex,signal processing cumbersome,the large error of measurement and identification results accuracy is not high.Therefore,in view of the shortcomings of the current research situation,in this thesis,three different structures of permanent magnet rotation(angular)acceleration sensor based on electromagnetic induction principle are proposed.The sensor is only sensitive to rotation acceleration.It can measure the change of the rotational acceleration(or rotational angular acceleration)of the rotary shaft caused by the torsional vibration torque directly and effectively.The structure is simple,and it can meet the needs of general torsional vibration testing of rotating mechanical system without destroy the original transmission system structure.This thesis completed the structural design of the sensor,electromagnetic design,prototype development,sensor normalization setting.The possible errors in the sensor design process are analyzed,at the same time,corresponding measures and methods of eliminating errors are given.Secondly,designed a vibration signal data analysis system based on LabVIEW software development platform in this thesis,according tothe analysis of the running state of rotating machinery system,the permanent magnet rotation(angular)acceleration sensor,USB data acquisition card and PC,construction of rotating machinery vibration monitoring signal measurement and data analysis system.The system can realize multi-channel vibration signal on-line detection,signal analysis and processing,data storage and playback,off-line analysis and so on.Finally,the torsional vibration of the brushless DC motor and shaded pole type motor is measured,and the vibration signal is analyzed and processed by the host computer system.The experimental results show that the permanent magnet rotation(angular)acceleration sensor can measure the torsional vibration of the rotating mechanical system directly and realistically.The signal acquisition and processing system can realize the real-time acquisition,processing and storage of the sensor output signal.Verified by experiment,the accuracy of the signal acquisition and processing system is about 2.556%.The research of this system provides a new method for the detection and fault diagnosis of rotating system.