Automatic Sorting System Research Articles

Sorting Task Optimization of Automatic Sorting System

In order to improve the whole sorting efficiency of automatic compositing sorting system in distribution center,a clustering method is proposed based on the similarity of stock keeping units(SKUs) and the balancing principle of sorting tasks.Compared with the traditional manual assignment of sorting scheduling policy,the method proposed not only solves the sorting-channel-frequent-exchange problem caused by the inconsistent of SKUs between different distribution routes,but also solves the imbalance of working tasks among multiple sorting systems.When the up-down hybrid picking system is used for the single distribution route,the tasks between the up-order-picking-line and down-order-picking-line,as well as the tasks of different channels within a single line,are often not balanced.So the picking task model is developed to minimize the difference of total picking amount between up-order-picking-line and down-order-picking-line and the mean square deviation among the picking tasks of different channels.In order to get the optimal assignment of sorting tasks,picking orders in the same distribution route are grouped by the distribution sequence and ant colony optimization(ACO) is applied to solve the model.Simulation result indicates that the sorting tasks between up-order-picking-line and down-order-picking-line can be assigned in terms of efficiency ratio which satisfies the working demands well in both efficiency and effectiveness.

Efficiency of automated sorter performance based on particle proximity information

The accurate prediction of automated sorter performance is important for the future application of this technology in the minerals industry. While it is known that sorter capacity increases with particle size, a method for predicting separation efficiency is not currently available in the literature. The separation efficiency depends on material properties, feed presentation and machine properties. In this study, we have undertaken colour separation of two materials chosen for their ease of identification using a TiTech Combisense® (BSM 063) automated sorter. Sorter performance was compared to particle proximity data obtained from the on-board counter of the automated sorter. Given the choice of feed materials, any inefficiency in sorter operation is related to the efficiency of selective air ejection which, in turn, is affected by feed presentation, feed size, compressed air valves characteristics as well as the sensitivity of the sorter. Deflection efficiency can be influenced by particle trajectories, precision of the air ejection system and the sensitivity of the sensors. The precision of ejection was also found to be an important factor with the unintentional removal of “accept” particles caused by their close proximity to particles being rejected. It was found that this loss of efficiency could be explained by “touching” particles forming aggregated groups at the identification point. An increase in throughput and a decrease in particle thickness were shown to increase the probability of finding these aggregates. As the fraction of particles to be deflected increases there is an increased probability of finding both “accept” and “deflect” particles within an aggregate and therefore an increased probability of co-deflection. A simple model for predicting the efficiency of our automated sorting system (assuming perfect identification) is presented which has only two variables, % belt loading and the fraction to be deflected.

Automatic sorting of lightweight metal scrap by sensing apparent density and three-dimensional shape

A new method for the automatic sorting of lightweight metal scrap has been developed to aid the recycling of scrap metal. The sorting system enables separation of relatively large metal pieces according to the differences in their apparent density and three-dimensional (3D) shape. Shape parameters such as width, height, volume, and projected area of irregular-shaped metal pieces moving along a conveyer are measured by means of a 3D imaging camera system consisting of a linear laser and camera with associated optics. The measured values of the weight and shape parameters are transferred to our own data-processing software that uses multivariate analysis. Mixed fragments of cast aluminum, wrought aluminum, and magnesium from an end-of-life vehicles shredder facility were sorted based on the output of the data-processing software. The results show that the developed automatic sorting system is a highly viable method that could replace conventional dense medium separation and manual sorting.

Study on Automated Scrap-Sorting by an Image Processing Technology

In this study, an automated scrap-sorting system using image processing technology has been designed and examined to automatically sort out specified materials from a mixture, especially Cu and other non-ferrous metal scraps from a mixture of iron scraps. In the functional tests of the system, its efficiency in the separation of Cu scraps from its mixture with Fe ones reaches to 75 % or more at a conveying speed of 20 m/min., and thus it is expected that the system can be commercialized in the industry of shredder makers if an automated sorting system of high speed is realized.

An Automated Near‐Infrared System for Selecting Individual Kernels Based on Specific Quality Characteristics

ABSTRACTAn automated sorting system was developed that nondestructively measured quality characteristics of individual kernels using near‐infrared (NIR) spectra. This single‐kernel NIR system was applied to sorting wheat (Triticum aestivum L.) kernels by protein content and hardness, and proso millet (Panicum miliaceum L.) into amylose‐bearing and amylose‐free fractions. Single wheat kernels with high protein content could be sorted from pure lines so that the high‐protein content portion was 3.1 percentage points higher than the portion with the low‐protein kernels. Likewise, single wheat kernels with specific hardness indices could be removed from pure lines such that the hardness index in the sorted samples was 29.4 hardness units higher than the soft kernels. The system was able to increase the waxy, or amylose‐free, millet kernels in segregating samples from 94% in the unsorted samples to 98% in the sorted samples. The portion of waxy millet kernels in segregating samples was increased from 32% in the unsorted samples to 55% after sorting. Thus, this technology can be used to enrich the desirable class within segregating populations in breeding programs, to increase the purity of heterogeneous advanced or released lines, or to measure the distribution of quality within samples during the marketing process.

Development of a Prototype Automated Sorting System for Plastic Recycling

Automated sorting for plastic recyclables has been seen as the way forward in the plastic recycling industry. Automated sorting provides significant improvements in terms of efficiency and consistency in the sorting process. In the case of macro sorting, which is the most common type of automated sorting, efficiency is determined by the mechanical details of the material handling system as well as the detection system. This paper provides a review on the state of-the-art technologies that have been deployed by some of the recycling facilities abroad. The design and development of a cost effective prototype automated system for sorting plastic recyclables is proposed and discussed.

An Automatic Sorting System Based on Pneumatic Measurement

For reducing the machining difficulty and increasing the conjunction precision, an automatic sorting system is presented. The system combines the backpressure pneumatic measurement with a pneumatic-electric transfer technology. A semiconductor pressure sensor is used for the pneumatic-electric transfer. The air chamber pressure is converted to an electrical signal. The merits of the semiconductor pressure sensor include high conversion precision, high frequency response, and small volume. But it has a relatively big temperature drift if no compensation is provided. The sensor can compensate temperature drift. But the null shift and sensitivity shift still exist. Reducing supply voltage using an electric bridge or reducing supply current using a constant current source can reduce the shift. The null shift and sensitivity shift can be further reduced by auto-compensation using a calibrated gauge. The automatic sorting system can automatically sort injector valves and orifices quickly with a resolution of 0.2µm. The sorting accuracy is 0.5µm and the speed is approximately thirty pieces per minute. The system has the function of auto-control and error auto-compensation and has a high measuring efficiency and high precision.

NON-DESTRUCTIVE LASER SORTING OF WHOLE TOMATOES

Spectroscopy techniques are used as non-destructive optical methods for evaluating the internal quality of many horticultural products. Laser-based visible spectroscopy is an appropriate tool for tomato analysis. There is a great change in the visible reflectance and transmittance spectrum of the tomato as it matures, so internal properties such as acidity, firmness, soluble solids content, pH, maturity index and dry matter can be evaluated and correlated with visible spectrum changes and the maturity stage. An automatic sorting system based on a laser facility and on predicted internal parameters would increase production quality. Internal reflectance measurements at 45° on the tomato surface calculated by using partial least squares resulted in the maximum correlation coefficient. With only a laser at one wavelength it is possible to determine the firmness and explain a 64% population variability. Smaller correlation coefficients were obtained for the other properties previously mentioned. The method of acquirement of measurements and arrangement of the experiment is set out.

비선형 마찰과 강성을 이용한 자동화 시스템 개발

In this study, we developed an automatic veneer sorting system controlled by nonlinear friction and nonlinear stiffness. With these nonlinear characteristics, it was difficult to analysis and to control the system in the fast. However it is necessary to consider nonlinear characteristics to satisfy accurate and rapid control demand in these days. We used not only nonlinear friction but also nonlinear stiffness and combined both to control the system. An experimental device was designed with 4 AC servo-motors and 2 Sensors. Through a series of experiment, we found nonlinear friction characteristics among roller versus veneer and veneer versus veneer and nonlinear stiffness characteristics with stacked veneers. Finally, we showed that the proposed control algorithm was very effective for veneer sorting system with nonlinear friction and stiffness.

APPLE CLASSIFICATION BASED ON SURFACE BRUISES USING IMAGE PROCESSING AND NEURAL NETWORKS

Maintaining prime fruit quality is the key to success in the fresh fruit business. Quality defects such as bruises inapples adversely affect their market value. Linescan xray imaging has shown potential for detecting these quality defects.Quality assessment of apples with computer vision techniques is possible; however, two basic issues must be addressed beforean automatic sorting system can be developed: (1) which image features best correlate with the fruit quality, and (2) whichclassifier should be used for optimal classification. These issues are discussed in this article. Red delicious (RD) and goldendelicious (GD) apples were linescanned for bruise damage. Spatial and transform features were evaluated for theirdiscriminating contributions to fruit classification based on bruise defects. Stepwise discriminant analysis was used forselecting the salient features. Spatial edge features detected using Roberts edge detector, combined with the selected discretecosine transform (DCT) coefficients proved to be good indicators of old (one month) bruises. Separate artificial neuralnetwork (ANN) classifiers were developed for old (one month) and new (24 hour) bruises. When an ANN classifier was usedto sort apples based on old bruises, it achieved an accuracy of 90% for RD apples and 83% (93% after threshold adjustment)for GD apples. For new bruises, the accuracy was approximately 60% for both RD and GD apples. New bruises were notadequately separated using this methodology.

Sorting of items on a moving conveyor belt. Part 2: performance evaluation and optimization of pick-and-place operations

The fundamental issues to be addressed in automatic sorting systems are sensing, i.e., detecting and classifying the objects to be sorted, and gripping, i.e., realizing the required separation in the most efficient way. While the sensing issue is considered in Part 1 of this work, the topic of this paper is the evaluation and optimization of the gripping performance. For a sorting system to have a “good” behavior, it is required to pick up “the more it is possible”, in terms of percentage of gripped objects with respect to the total (gripping rate), and in terms of gripped objects per time unit (throughput). In the sorting of recyclable packaging (considered here as in Part 1 of this work), the flow of incoming items cannot be controlled and only its stochastic description may be known, so that the optimization of the above indices is a crucial and not trivial issue. Here, the problem is addressed at two different levels: first, different robot kinematics are characterized in terms of the parameters that affect the system performance, proving that the choice of a suitable kinematic structure is the first available tool to get a satisfactory system behavior. Then, for the class of redundant (or flexible) kinematic devices, the system performance is shown to depend on the strategy that governs the gripping order for the items on the belt. For this nonstandard scheduling problem, two innovative solutions have been devised, based on suitable modifications of standard queuing strategies. The proposed algorithms have the same complexity of the corresponding standard ones, but improved performance in the considered case, as confirmed by the reported simulation results.

Comparing Grade Classification Criteria for Automatic Sorting of Norway Spruce Saw Logs

Grades of centre and side boards from 277 Norway spruce logs were combined to form binary response variables, here denoted as sorting criteria. Four different grading systems were tested. The log geometry variables unevenness, butt taper and top taper were used in logistic regression models. The classification accuracy ranged from 58 to 83%. The accuracy was higher for visual stress grade criteria than for more complex criteria such as the Nordic timber grading rules. The number of tested criteria and thus possible comparisons limited the ability to establish significant differences. The low associations between board grades within logs and between graders, highlight key issues when developing and improving automatic log sorting systems.

An automated sorting system (ASS) for distinguishing groups of radiation risk

1. An automated sorting system (ASS) has been developed on the basis of nonstatistical methods of pattern recognition and algorithms of estimate computation.

A Computer System for Photometric Mineral Sorting

The sorting of minerals is often done manually based on visual information. The human limitations, such as boredom, fatigue, lack of motivation, etc. can influence the sorting process and make worse the result. In most cases the sorting result, and moreover the recovery of the process, can be improved by an automatic sorting system. This sets, however, very high requirements for the system performanceThe limestone quarries of Partek have been provided with an automatic, microprocessor based sorting system. The system has been designed to be very easily adapted into various surroundings and requirements. The experiences have so far been very positiveThe system contains several computing units connected to a common bus. Due to parallel processing and special hardware modules the system is very high speed and functions in real time. The visual information from a semiconductor camera is analyzed by a preprocessing unit, which extracts different feature values for recognition. These values are fed to classification units for final classification. The whole operation is controlled by a master processor, which also communicates with an operator

How voice and laser can raise distribution efficiency

One of Japan's largest distribution centres has introduced an automatic sorting system using voice input. The workforce has been halved.

Texture analysis of phosphor screens

Describes a method using the optical Fourier transform to test cathodo- and photoluminescent screens. The transmittance spectrum is obtained and studied. Screen texture can be either uniform or clustered. From results on cathodoluminescent electrophoretic screens good performance of uniformly textured screens is related to a monotonically decreasing spectrum in the spatial frequency domain. Screens showing grain clusters can be easily identified during manufacture by their Fourier spectrum instead of by microscope observation. The consequences of a clustered structure in screens operating either by electron or X-ray excitation are briefly discussed. When the average cluster dimension must belong to a determined range the optical Fourier transform enables an automatic sorting system to be implemented.

An automated gaging and sorting machine : Aki Iwata, Norm Queen and Fred Tanaka. Solid-St. Technol. p. 29 (August 1976)

The automatic sorting system has been reported to be complex and a global problem. This is because of the inability of sorting machines to incorporate flexibility in their design concept. This research therefore designed and developed an automated sorting object of a conveyor belt. The developed automated sorting machine is able to incorporate flexibility and separate species of non-ferrous metal objects and at the same time move objects automatically to the basket as defined by the regulation of the Programmable Logic Controllers (PLC) with a capacitive proximity sensor to detect a value range of objects. The result obtained shows that plastic, wood, and steel were sorted into their respective and correct position with an average, sorting, time of 9.903 s, 14.072 s and 18.648 s respectively. The proposed developed model of this research could be adopted at any institution or industries, whose practices are based on mechatronics engineering systems. This is to guide the industrial sector in sorting of object and teaching aid to institutions and hence produce the list of classified materials according to the enabled sorting program commands.

Separation of sphalerite, silica and calcite from flourspar

The use of air jigging for performing multi-component separation in the treatment of mixed construction and demolition waste was studied. Sorting tests were carried out with mixtures of equal bulk volume of concrete and brick in which fixed quantities of unwanted materials - gypsum, wood and paper - were added. Experimental results have demonstrated the possibility to use air jigging to carry out both the removal of low-density contaminants and the concrete concentration in only one process step. In relation to the removal of contaminants only, the overall performance of jigging process can be comparable with that of commercial air classifiers and automatic sorting systems. Also, the initial content of contaminants seems does not have a significant effect on the separation extent. These results are of particular importance for recycling plants processing as they represent an alternative to optimize the use of air jigs. Further investigation is needed in order to evaluate the practical feasibility of such method.