Measurement Method Of Fruit Size Based On Multi-sensor Information Fusion

Fruit grading technology plays an important role in realizing the industrialization of agricultural products and making fruits a standardized commodity.The size of the fruit is an important basis for fruit grading.The traditional manual grading method has problems such as low efficiency,poor consistency and unquantifiable.In view of the above deficiencies,that studies a method to quickly obtain fruit size parameters by fusing multi-sensors,and provides an objective and stable reference for fruit grading.The main researches are as follows:(1)Affected by the distortion of the binocular lens,the image of the object under test is distorted;Therefore,after analyzing the geometric model,measurement principle,and stereo matching principle of the binocular camera,the binocular camera is calibrated by Zhang Zhengyou’s calibration method,and the binocular camera is calibrated by MATLAB.The dual-target calibration toolbox completes the calibration experiment;for the image distortion of the measured object,the calibration parameters are used to perform stereo correction.(2)Perform stereo matching on grapefruit and cantaloupe based on the SGM algorithm,and analyze the influence of different parameter settings on the matching results;The stereo matching results are reconstructed in three dimensions to form a dense point cloud,and the volume of the measured object is calculated through the point cloud data.And then the 3D reconstructed point cloud is subjected to spatial transformation,denoising,segmentation of the measured object,and spatial position correction.(3)The principle of ultrasonic sensor ranging is analyzed,and the ultrasonic sensor array is constructed and calibrated.The method of converting the measurement data of ultrasonic sensor into three-dimensional coordinates is introduced,and the body size parameters of the measured object are calculated.The feasibility of the method is verified by experiments on plane,curved surface,spherical surface and grapefruit.(4)The measurement data of the binocular camera and the ultrasonic sensor array are fused,and the fusion method is introduced.A comparative measurement experiment was carried out on the previously measured grapefruit,and the experimental results showed that the volume of the grapefruit calculated after data fusion was closer to the real value.The experimental results show that the measurement method of multi-sensor data fusion has high accuracy and provides a reliable reference for fruit grading;in actual production,it provides a measurement method for fruit packing.