Research And Implementation Of Multi-channel Electromagnetic Relay Contact Jitter Detection Technology

In this paper,the dither fault which happens in the inaccuracy break and closure of normally-closed contact and normally open contact when the relay is tested in the experiments of vibration and shock is under research with the operating state of relay contact as the research object.By analyzing the advantages and disadvantages of different detection devices,FPGA is selected as the core of the detection module.And the selection of the device is completed according to the performance parameters of FPGA.The detection system mainly includes input circuit module,pulse detection module and upper computer software.The pulse detection module can simultaneously measure the random pulse signal of 40 channels and realize the parallel expansion of more channel jitter pulse signals.The input signal is generated by the self-designed relay circuit module,and the mechanical jitter of relay contact is converted into electrical signal.Environment is filled with all kinds of white noise,such as interference between analog channel and digital channel,the dither signal of button switches,wiring connection of different equipments disturbing detection circuit.Therefore,in the actual design process,the software and hardware anti-interference filter design is added to eliminate the interference signal.Since the acquisition rate of the pulse signal is far more than the speed of the transmission priority machine,if the data is not stored in in the corresponding RAM timely,the data will be lost.Considering that the FPGA of synchronous FIFO and pulse detection module can share a single clock source logically,it is easy to do that.So the synchronous FIFO is used to implement the writing and reading of data.The data is framed and uploaded to the upper computer via the serial data bus.The PC software is designed to match the pulse detection module,using LabVIEW to design related interface,which its characteristic is that the logic state can be accomplished through the visual graphics.The program designed in this paper mainly implements the configuration of serial communication parameters,data solution frames,visual display,and the storage function in the form of text or other data.In the debugging phase,the method of debugging is put forward,and the problems and solutions that are easy to appear in debugging are analyzed.After that,the overall system is debugged and tested through the experiment to get some test data,compared with technical indicators,and then system defects and improvement measures are analyzed.