Research On The Detection Of Three-dimensional Deformation Of Potato Slices During Drying

Potatoes are rich in nutrients and are also one of the main food crops in China They have a large planted area and high production,but the processing rate of potatoes only accounts for 14%of the total,which is very low.Drying is the most commonly used processing method that can effectively extend the shelf life of potatoes.The shrinkage deformation and structural properties of the potato during the drying process will affect its final quality.Therefore,the monitoring of the three-dimensional information during the drying process of the material is not only conducive to observing the change of the material shape visually,but also provides conditions for the study of material morphology and drying process parameters in the later period regularly,and improves the quality of potato drying.The specific research contents of this paper are as follows1.A set of ring tunnel hot air drying device is designed,which mainly includes the design of its mechanical structure,temperature and humidity control system and wind speed control system.The designed temperature and humidity control system is controlled by the upper and lower limit adjustment methods.It is found through testing that the deviation is controlled within 0.429?1.321? when the set value is in the range of 50??80?.The control accuracy of 50%and 10%humidity is good,and the deviation range of the final stable mean is 0.366?1.176%and 0.153?2.043%,respectively.Therefore,the designed hot air drying device can meet the needs of this research experiment2.A three-dimensional morphology detection system for potato slices drying process was built,which can collect and save three-dimensional information.Convert the depth information into 2.5D grayscale images,in order to extract potato slices and process the original depth images,region segmentation,hole filling,morphological corrosion and median filtering were implemented,and extract three characteristic parameters of maximum value,average value and projected area.Using preset depth value range,SOR and radius filtering,greedy projection triangulation,and Laplace algorithm to segment and reconstruct 3D point cloud data,and Gaussian curvature and average curvature were extracted to characterize the change of curl degree of potato slices during the drying3.In order to explore the influence of potato diameter and thickness on height characteristics,a two-factor three-level test was conducted under a drying environment of temperature 70?,wind speed 4 m/s,and humidity 10%.The test results show that when the thickness of potato slices is the same,the maximum value,average value and projected area at the end of drying increase with the increase of the diameter.4.In order to study the influence of the shape of the potato itself and the drying environment on the three-dimensional deformation characteristics,four single-factor tests of thickness,diameter,wind speed and temperature were carried out.The test results showed that as the thickness increases,the curling rate of potato slices also slows down,and the curling speed of 1mm thick potato slices is the fastest;Potato slices of different diameters have little effect on the Gaussian curvature and mean curvature;Wind speed has a significant effect on the curling speed of potato slices.As the wind speed increases,the curling speed also increases;the temperature increases and the curling speed of potato slices increases.The three-dimensional characteristics and water ratios obtained by the four sets of single factor experiments were fitted with four shrinkage empirical models.The fitting results show that the Exponential model has good applicability,the correlation coefficient R2 can reach 0.99,and the root mean square error is lower than 0.0169.