Clamping Device For Detection Of Moldy Core In Apples

Apple planting occupies a very large proportion of China's fruit industry.According to statistics,China's apple planting area is around 35 million acres and the production is 39.684 million tons in 2015,accounting for more than 50% of the world's total apple production.However,affected by moldy core in apples and other factors,China's overall fruit quality is not good enough.According to a survey,apple drop is very serious before harvest in Shaanxi,Shanxi and other producing areas,and the number of apple drop is between 500~1000kg per acre resulting in huge economic losses.At present,for the status quo of this industry,scholars have carried out a lot of research on the methods of nondestructive detection of moldy core in apples,obtaining certain achievements,among which the nondestructive detection technology based on visible or near infrared spectroscopy is the most important one.Nevertheless,the majority of research results are still in the laboratory stage,as the cost is high and difficult to put into use.Moreover,there are rare studies probing the nondestructive detection of moldy core in apples.This study designed a clamping device for quick nondestructive detection of moldy core in apples cored on MSP430 based on the transmission spectrum detection method of narrowband LED light source.The discriminate model was developed based on the BP network using the dual-band transmitted light intensity,realizing the non-destructive detection of moldy core in apples and providing a viable solution to investigate the incidence of moldy core in apples in different areas and to classify apples in harvest.The main work and the conclusions of this study are as follows:(1)The pathogenesis of moldy core in apples was analyzed,and the detection method of transmission spectrum was determined.According to the theory of absorption of light in the spectral transmission,the influencing factors of the transmitted light intensity were determined as fruit diameter and pathological substances of moldy core.By using the collected apple transmission spectrum from the visible or near-infrared transmission spectrum acquisition platform for apple combined with the incidence of moldy core in apples and fruit diameter,the most relevant characteristic wavelength of moldy core in apples is 700nm-720 nm applying the correlation analysis of MATLAB.At the same time,considering the influence of fruit diameter on the optical path length of the transmitted light,800nm-820 nm was extracted as a reference wavelength of the clamping device for detection of moldy core in apples.(2)A whole mechanism of clamping device for detection of moldy core in apples was designed.The equipment linked by connecting rods was made of hand control valve and clamping device which consists of two hemispherical mechanical claws that were equipped with LED light source and photoelectric detection sensor.When mechanical claws closed the positions of light source and photoelectric sensor were settled to ensure that the light through apples emitted by the light source was received by the photoelectric detection sensor vertically.The hand control valve was used to control the opening and closing state of the clamping device.The whole mechanism provided the carrier for the detection of moldy core in apples.(3)The hardware circuit and software program of the clamping device for detection of moldy core in apples were achieved.Based on the selected characteristic wavelength and reference wavelength of moldy core in apples,narrowband LEDs with center wavelengths of 710 nm and 810 nm were selected as the detection light source respectively.Combining with the photoelectric detection sensor and A/D sampling module,hardware circuit design with the MSP430 microcontroller as the core processor which provided a reference for the design of the software operational process of the equipment realizing the detection of the transmitted light intensity of the equipment.(4)The discriminant model of moldy core in Fufeng Fuji apples based on BP neural network was developed.The dual-band transmitted light intensity of the sampling apple was collected using the clamping device for quick nondestructive detection of moldy core in apples.The satisfactory neural network was trained by MATLAB software.Derive the weight matrix and threshold matrix of the BP network,and then combining the intermediate variable the discriminant model of moldy core in apples was established which can be used in MSP430 single chip microcomputer by using the network transfer function to calculate.The accuracy of the whole discrimination was 88.9% by testing 45 samples.(5)The test results of the hand-held detection equipment of moldy core in apples revealed that the detection time for a single apple was 1 to 1.5s;the standby power of the equipment was 1.57W;the power of the equipment in use was 8.95W;the capacity was 5000mAH;it was powered by 24 V lithium battery;and it can work more than 8 hours with the battery power greater than 50%.