Design and Development of an Integrated Thin Drawbar Transducer for an Agricultural Tractor

Abstract

The objective of this research work is to design, develop and calibrate a transducer for measuring the horizontal drawbar pull of an agricultural tractor. The transducer design is based on a thin proof ring that forms an integral part of the drawbar element with strain gauges banded on the inside and outside curvatures of the proof ring. The strain gauges are arranged in a full bridge constant current circuitry and interfaced to a data acquisition system. Static calibration tests on the transducer showed high degree of linearity between applied load and output volt with coefficient of correlation R2 equal to 0.9968. The transducer measurements accuracy was within the acceptable range limits with measurement errors not more than 0.67% of the measured force magnitudes under static measurements. The data acquisition system was able to successfully scan and record the transducer signals as programmed. The developed transducer can be part a complete instrumentation system to be used for developing comprehensive information database on power and energy demand of various tractor field operations in Sudan.