Research On Motor Speed Measurement Technology Based On Friction Electrification

With the rapid development of information technology,human society is in the transition from the traditional industrial era to the information age.The demand for sensors in various fields is increasing day by day.Sensors are needed to obtain a lot of information,which puts forward higher requirements for sensors.Traditional sensors are mainly made of metals,semiconductors,ceramics and so on.The fabrication process and structure are complex,and the cost is high.The flexible polymer sensor is generally made of polymer material,which has certain softness and flexibility and low production and processing cost.Based on the principle of friction electrification,flexible polymer materials can be made into sensors for motor speed measurement and motor attitude evaluation.The main research work of this paper is as follows:Based on the flexible sensor technology,a sensor model is designed for the application of measuring motor speed,and the electrostatic field inside the model is simulated by the finite element analysis method.Based on the simulation results,a sensor prototype is designed for preliminary experiments.By changing the number of pellets,the number of copper foil electrodes and the width of copper foil electrodes,the stability of the prototype is monitored at different rotating speeds to determine the best working range and accuracy.Then the application of the prototype is extended to monitor the motor balance.When some mechanical equipment such as UAV,CNC machine tool,robot,automobile and so on move,the internal motor will also produce the attitude change.At this time,the sensor can also collect the signal of the motor attitude change.After the simulation analysis to determine the size of the prototype,a prototype of motor speed measurement sensor based on flexible sensor technology is made,and an experimental platform is built for testing to determine the actual effect,and compared with the existing measurement methods.Due to the principle of friction nano generator,the signal output of the prototype is relatively small,and it is easy to be interfered by power frequency.In the signal acquisition,we need to design a collection circuit,including signal amplification and filtering functions.First of all,the feasibility of the prototype is preliminarily tested.It is found that the PTFE ball can contact and rub with the copper foil electrode periodically when the prototype is rotating,and output a sine wave signal,and the voltage amplitude is volt level.Next,the prototype is fixed on the experimental platform,and the comparative experiments of single PTFE ball and double PTFE ball,double electrode and four electrode,the experiment of changing the size of PTFE ball and the acceleration and deceleration experiment of the prototype are carried out respectively.Through the above experiments,several factors affecting the output characteristics of the prototype are analyzed,and a scheme closest to the real speed is determined,and the scheme is measured The rotational speed of the motor is basically the same as that of the real motor.Finally,the balance of the prototype is tested to monitor the motor attitude.The test results show that when the motor attitude changes,the prototype can accurately show the direction and size of the change.The above experiments show that the motor speed sensor based on flexible sensing technology can accurately measure the motor speed and analyze the motor attitude,which is consistent with the theory.