Sensing Technologies for Grain Crop Yield Monitoring Systems: A Review

Abstract

Purpose: Yield monitoring systems are an essential component of precision agriculture. They indicate the spatial variability of crop yield in fields, and have become an important factor in modern harvesters. The objective of this paper was to review research trends related to yield monitoring sensors for grain crops. Methods: The literature was reviewed for research on the major sensing components of grain yield monitoring systems. These major components included grain flow sensors, moisture content sensors, and cutting width sensors. Sensors were classified by sensing principle and type, and their performance was also reviewed. Results: The main targeted harvesting grain crops were rice, wheat, corn, barley, and grain sorghum. Grain flow sensors were classified into mass flow and volume flow methods. Mass flow sensors were mounted primarily at the clean grain elevator head or under the grain tank, and volume flow sensors were mounted at the head or in the middle of the elevator. Mass flow methods used weighing, force impact, and radiometric approaches, some of which resulted in measurement error levels lower than 5% (R 2 = 0.99). Volume flow methods included paddle wheel type and optical type, and in the best cases produced error levels lower than 3%. Grain moisture content sensing was in many cases achieved using capacitive modules. In some cases, errors were lower than 1%. Cutting width was measured by ultrasonic distance sensors mounted at both sides of the header dividers, and the errors were in some cases lower than 5%. Conclusions: The design and fabrication of an integrated yield monitoring system for a target crop would be affected by the selection of a sensing approach, as well as the layout and mounting of the sensors. For accurate estimation of yield, signal processing and correction measures should be also implemented.

Experiments and Analysis Advance R2100 Distance Sensors Used for Safety Systems of TOMI

“…From Figure 1 to Figure 6 and Table 1, Table 2, It can be seen that the accurate results of adaptable scanning distances ranges which between 4 serious of obstacles targets and advance R2100 distance Sensor in static tests and dynamic tests, which operating methods were complied with ISO standards of Agricultural machine's safety operational systems [22][23][24][25][26][27], it was shown in Figure 5, the box, cone, cylinder and the first author targets were set at 0°, 14°, 44°, 74° and 88° angle with the reference of the R2100 sensor at center, and every 5 regression equations showed the relationships between the target's actual R2100 Distances value and the theory value of R2100 sensor at the height of 240, 420 mm, respectively. the accuracy tolerate and suitable height also were evaluate of person target at 240, 420, 850 mm height in Figure 5 and Figure 6, the results from Test 1, Test 3 and Test 5 showed that the average R2 is up to 98.96%, when R2100 sensor was setting at the height of 420 mm in TOMI robot working in complex fields, it showed that the R2100 sensor setting on 420 mm height is more accurate scanning person than 240 and 850 mm height.…”

Site-specific Crop Nutrient Management for Precision Agriculture – A Review

“…Long term yield monitoring makes a remarkable GIS dataset that helps farmers to effectively recognize spatial yield variability within a field for better decisions of variable-rate application. Research and commercialization of this technology had been done for several crops such as grain crops [100], maize [101], groundnut [102], Sugarcane [103], cotton, potato, onion, sugar beet, tomato etc [104].…”

Development and Test of Grain Mass Flow Monitoring System Based on Pressure Sensor

“…It provides decisionmaking basis for variable seeding and fertilization, and provides data and technical support for the full implementation of digital agricultural technology [1][2] . At present, grain quality flow monitoring technologies mainly include various monitoring methods such as impact type, photoelectric type, and weighing type [3][4] . The impulsive flow monitoring method is the most widely used.…”