Design, implementation and evaluation of a potato yield monitoring system

In this paper the design، implementation، and evaluation of an experimental-scale potato yield monitoring system is presented. The main objective of this research was to develop a method for accurate mapping of potato yield. At the first stage an instantaneous yield monitoring system was mounted on a potato harvesting machine. This system consisted of a weighing tray، two load cells، a shaft rpm encoder، a PLC controller and a mobile computer. The PLC controller، which was able to communicate with the mobile computing unit through the control applications developed in Visual Basic and Win-Proladder، was capable of encoding the load cells and other sensors and making decisions by analyzing the obtained records. Laboratory tests were conducted on a potato harvesting machine to evaluate the performance of the system. The independent variables were: forward speed، tray angle، and the thickness of shock absorber plate. To analyze and compare the results of the laboratory data، Duncan''s test with confidence level of 95% was used. In order to investigate the interactions of various factors the factorial experiment with completely randomized design was used. In examining the interactions of tray angle، forward speed and performance-related shock absorber on the system performance، the highest performance (with 2. 81% error) only was found to be at the tray angel of 37 degrees، forward speed of 2 km h-1 and without shock absorber.