Improving Design of a PVDF Grain Loss Sensor for Combine Harvester

Liming Zhou,Junning Zhang,Yanwei Yuan,Kang Niu

doi:10.1007/978-3-030-06179-1_21

Abstract

Online monitoring of grain loss is important to improve the efficiency of combine harvester. The traditional grain loss sensor needs to be frequently calibrated for different materials. In order to solve this problem, the grain loss sensor was developed based on PVDF (Polyvinyliden Fluoride) films. The band-pass filter based on LTC1068-200 was designed by frequency spectrum analysis of the wheat and rice grain impact response. And the dynamic voltage comparator with adaptive regulation of the threshold voltage according to the intensity of sensor signal was introduced here. Wheat and rice grain samples with different moisture content were prepared for the experiments and the results indicated the sensor had high measurement accuracy to the different samples.

Highlights

Grain loss is the key index for measuring the operating performance of the combine harvester
Liang proposed an impact type piezoelectric sensor for grain sieve loss monitoring, the signal conditioning circuits were developed to discriminate for full grains [8-9]
The accuracy of this acoustic grain loss sensor is severely constrained by working conditions, and the noise is a fatal factor for the acoustic sensor [10]

Summary

Introduction

Grain loss is the key index for measuring the operating performance of the combine harvester. With the development of sensors, electronics and information process technologies, the demand for precise and intelligent detection system for grain loss are rising. Online grain loss monitoring is important to improve harvest efficiency and quality operations. Liang proposed an impact type piezoelectric sensor for grain sieve loss monitoring, the signal conditioning circuits were developed to discriminate for full grains [8-9]. It is very difficult to fit the different type of grains (such as rice and wheat) adaptively because of the fixed threshold voltage of the signal processing circuit. Since the kernel of grain is much harder than the straw, acoustic sensor had been used to detect the grain loss of harvester. An array sensor made from PVDF film is designed to determine the grain loss [12].In this paper, how to design the effective signal conditional circuit of the PVDF grain loss sensor was introduced to improve the resolution between the grain and stems

Methods

Results

Conclusion