Mathematical modelling applied for the resonance frequency sensor in the light of the reverse logistics system

Prior to the process,when the shredded waste paper in factory is pressed into pellets,as a part of the chain in the context of the reverse logistics,the pieces of paper pass through the chamber. as paper pieces flow through the chamber with the pressing apparatus,the overfilling can cost the damage and stop the process. the sensor can detect overfilling in the pressing apparatus giving timely signal to the service staff. the designed sensor is constructed as a vibration rod that is based on the measuring and evaluating the resonance frequency using the sensor circuit board (pcb) with microprocessor. evaluation of the vibrations,as an expression of the sensor vibrating rod,is realized through assembler. the crystal frequency is 24 mhz,while the rod frequency is 55.5hz. the damped vibrations of the sensor were modeled. the amplitudes were expressed using the least squares method for the curve fitting. the differential equation was used to determine the damping ratio of the system. © 2016,penerbit utm press. all rights reserved.