The Research Of Tension Control On A New Medical Paper-rewind Machine

This article researches the tension control system on a new medical paper-rewind machine.The control system and mechanical structure are designed.The dynamic mathematical model is established.The tension control is realized by the stable linear speed controlled by PID method and this tension control system is developed on Siemens PLC S7-300.Following the research,the paper-rewind machine is compliance to medical production requirement.The physical sample is delivered and validated by on-site experiment.Detail research content as follows:This paper compares several classical re-wind machines,analyzes the development situation of re-wind machine and tension control method,and researches the typical tension control method.The research content is presented.The hardware of rewind machine is designed,and the design proposal,mechanical structure and critical sensors are expounded.The tension control strategy of this medical paper-rewind system is finalized via the mechanical analysis;it is to control the linear speed gap between re-wind and un-wind point.In order to control the linear speed,the dynamic mechanical analysis is carried out;the mathematical model is established based on the dynamic mechanical analysis.The mathematical model is simulated by Matlab Simulink software;linear speed and reel diameter are defined as critical factors for tension changing.The linear speed must be managed following reel diameter changing,so that the tension is maintained during rewinding,A new medical paper-rewind machine is developed on Siemens PLC S7-300 system.This machine has 2 AC servo motors as unwind and rewind drivers.Because the unwind/rewind linear speed is adjusted following reel diameter “r” changing,incremental PID method is applied to obtain the tension setting for different material and different thickness.And the tension is maintained by the stable linear speed gap between rewind and unwind reel.Finally the machine is validated by on-site experiment.It fully meets the design requirements.After rewinding,the paper/film reel owns the good tension and flat ends.The machine is deliverable.This paper completes the simulation with dynamic mathematical model.The critical affect factors are identified.The machine is designed using incremental PID method.Validation proved the system is available,and the machine meets the design requirements.It is a good experience for all other web rewind machines.