Iman Ahmadi - Department of Agronomy, Khorasgan (Isfahan) Branch, Islamic Azad University, Isfahan, Iran
Saeed Minaei - Department of Mechanical Engineering of Farm Machinery, Tarbiat Modarres University, Tehran, Iran
Mohammad Ali Ghazavi - Mechanics of Agricultural Machinery, Shahrekord University, Shahrekord, Iran

Before fabrication of any system, development of its simulation model can improve designer'sunderstanding about strengths and weaknesses of the system. As a result, fabrication phase can bedone without trial and error method. In this study a simulation model for alfalfa hay yield monitoringsystem on the baler was developed. Simulation of the yield measuring section led to the numericalsolution of a first order differential equation. Dead reckoning method was used for simulation of thecoordinates determination section. According to the results of this study: In the model of yieldmeasuring section, the retardation time was shown. This retardation time is considered to take intoaccount the required time for reaching crop from the ground to the baling channel. There were jaggedshapes in the simulated data which coincide with changes in type of data variations. Therefore whenthe measured data faced a sudden change, a jagged shape will result in the simulated data. It wasrecommended to use each bale bulk density measuring system on the baler. In order to increase theaccuracy of the coordinates determination section, it was essential to use ballast or spring pressure onthe ground wheel.

Yield monitor, Simulation model, Baler