| Elastic coupling has an important role in transmitting torque,eccentric compensation,vibration absorption,etc.,and has been widely used in the mechanical transmission industry.With the increasingly high requirements for transmission accuracy,we generally focus on the control accuracy of the motor,bearing accuracy,machining accuracy of mechanical parts,etc.,and often ignore the impact of the coupling,only as a connecting element,but ignore the impact of coupling performance on transmission accuracy.Although the elastic coupling has the function of shock mitigation and vibration absorption,as the connection part of shaft and shaft,the elastic material has elastic hysteresis effect in the process of torque transmission between the two shafts,which will lead to the relative angular displacement between the active shaft and the passive shaft,and the phenomenon of "the go does not go,the stop does not stop";especially in the application of frequent start/stop,this kind of hysteresis will lead to the problem of "the go does not go,the stop does not stop".Especially in the application of frequent start-stop,this hysteresis effect will always accumulate,causing large movement deviation.Therefore,in order to improve transmission accuracy,it is necessary to solve the problem of high-precision testing of static and dynamic performance of flexible couplings.As torque and angle are important parameters of flexible couplings,this paper designs a high-precision synchronous acquisition system for coupling test bench based on FPGA(Field Programmable Gate Array).First,the angle measurement function of the angle grating is used to acquire the coupling swing angle,and the grating probe acquires the angle position signal on the scale,converts it into binary angle information and sends it to the FPGA for protocol decoding through the BISS protocol.Torque information is acquired from the disk-coupled torque transducer and then transmitted as a differential frequency signal to the NI9608 data acquisition card integrated in the FGPA.The torque data and rotary angle data are collected simultaneously at high speed and stored efficiently.Secondly,the five-point triple filtering,Savitzky-Golay(SG)filtering method is used to process the collected data.The data are imported to observe the filtering performance and filtering effect.Mathematical modeling and simulation analysis of the flexible plate in the test bench were carried out to study the effect of vibration on the measurement accuracy.It was brought into the built mathematical model to get the change curve of the parameters of the applied damper on the vibration suppression effect,so as to finally determine the parameters of the additional damper.And the software system was designed by C#,including data acquisition,coupling test,human-machine interface,report generation,etc.Finally,the experiments show that the measurement device works well under the conditions of adapting to different rotational speeds,different sampling frequencies and complex communication environment,and the system is suitable for torque measurement of couplings,which has good use value and promotion prospect. |
