1. Analysing picking errors in vision picking systemsEla Vidovič, Brigita Gajšek, 2020, original scientific article Abstract: Vision picking empowers users with access to real-time digital order information, while freeing them from handheld radio frequency devices. The smart glasses, as an example of vision picking enabler, provide visual and voice cues to guide order pickers. The glasses mostly also have installed navigation features that can sense the order picker's position in the warehouse. This paper explores picking errors in vision systems with literature review and experimental work in laboratory environment. The results show the effectiveness of applying vision picking systems for the purposes of active error prevention, when they are compared to established methods, such as paper-picking and using cart mounted displays. A serious competitor to vision picking systems are pick-to-light systems. The strong advantage of vision picking system is that most of the errors are detected early in the process and not at the customer's site. The cost of fixing the error is thus minimal. Most errors consequently directly influence order picker's productivity in negative sense. Nonetheless, the distinctive feature of the system is extremely efficient error detection. Keywords: order picking, storage operations, warehousing, smart glasses, error prevention, inventory management, intralogistics Published in DKUM: 22.08.2024; Views: 83; Downloads: 4 Full text (672,66 KB) This document has many files! More... |
2. Single-tray VLM vs dual-tray VLM : quantitative throughput comparisonGoran Đukić, Tihomir Opetuk, Brigita Gajšek, Tone Lerher, 2021, original scientific article Abstract: In this paper quantitative comparison of resulting throughputs for single-tray and dual-tray VLM devices is presented. Comparison is based on mathematical models for throughput approximating dual command times of VLM's crane, for selected parameters of VLM device (height and crane's velocity) and selected picking times per delivered tray. Analysis showed that throughput increase achieved by using dual-tray VLM's depends mostly on the average picking time relative to the expected dual command time of the VLM's crane. Highest improvements are possible for picking time equal to expected dual command time and amounts over 80%, however for extremely low or high picking times improvements are significantly reduced. Keywords: order-picking, throughput model, vertical lift module systems, quantitative analysis, intralogistics, dual-tray VLM, single-tray VLM Published in DKUM: 12.08.2024; Views: 48; Downloads: 9 Full text (1009,78 KB) This document has many files! More... |
3. Bi-objective assignment model for lean order picking in a warehouseBrigita Gajšek, Hrvoje Cajner, Tihomir Opetuk, Goran Đukić, Marcin Butlewski, 2022, original scientific article Abstract: With the introduction of Lean Warehousing, we are committed to using lean principles for more efficient warehousing operations, which are performed with quality and safety. Manual order picking, on which the paper is focused, is currently considered the most unfriendly to humans because, in the long run, it contributes to the appearance of musculoskeletal disorders. We record not only the increase in the average age of employees in warehouses but also in the number and duration of sick leave due to back and muscle pain. This paper explores the possibility of productive work while preventing order pickers from Work-Related Musculoskeletal Disorders. Using a laboratory experiment, we determine retrieval times for units with different characteristics and study required postures by guidelines of Revised NIOSH Lifting Equation. The final goal is to create a bi-objective assignment model. Keywords: warehousing, order picking, ergonomics, intralogistics, lean logistics, manual order picking, productivity, revised NIOSH lifting equation, warehousing, work-related musculoskeletal disorders Published in DKUM: 13.06.2024; Views: 105; Downloads: 8 Full text (802,52 KB) This document has many files! More... |
4. Robotic bin-picking : benchmarking robotics grippers with modified YCB object and model setTone Lerher, Primož Bencak, Luka Bizjak, Darko Hercog, Boris Jerman, 2023, published scientific conference contribution Abstract: Robotic bin-picking is increasingly important in the order-picking process in intralogistics. However, many aspects of the robotic bin-picking process (object detection, grasping, manipulation) still require the research community's attention. Established methods are used to test robotic grippers, enabling comparability of the research community's results. This study presents a modified YCB Robotic Gripper Assessment Protocol that was used to evaluate the performance of four robotic grippers (twofingered, vacuum, gecko, and soft gripper). During the testing, 45 objects from the modified YCB Object and Model Set from the packaging categories, tools, small objects, spherical objects, and deformable objects were grasped and manipulated. The results of the robotic gripper evaluation show that while some robotic grippers performed substantially well, there is an expressive grasp success variation over diverse objects. The results indicate that selecting the object grasp point next to selecting the most suitable robotic gripper is critical in successful object grasping. Therefore, we propose grasp point determination using mechanical software simulation with a model of a two-fingered gripper in an ADAMS/MATLAB cosimulation. Performing software simulations for this task can save time and give comparable results to real-world experiments. Keywords: intralogistics, robotic bin-picking, YCB protocol, robotic gripper evaluation, mechanical software simulations, performance analysis Published in DKUM: 21.03.2024; Views: 298; Downloads: 11 Full text (773,38 KB) This document has many files! More... |
5. Indoor positioning system based on bluetooth low energy technology and a nature-inspired optimization algorithmPrimož Bencak, Darko Hercog, Tone Lerher, 2022, original scientific article Abstract: Warehousing is one of the most important activities in the supply chain, enabling competitive advantage. Effective management of warehousing processes is, therefore, crucial for achieving minimal costs, maximum efficiency, and overall customer satisfaction. Warehouse Management Systems (WMS) are the first steps towards organizing these processes; however, due to the human factor involved, information on products, vehicles and workers may be missing, corrupt, or misleading. In this paper, a cost-effective Indoor Positioning System (IPS) based on Bluetooth Low Energy (BLE) technology is presented for use in Intralogistics that works automatically, and therefore minimizes the possibility of acquiring incorrect data. The proposed IPS solution is intended to be used for supervising order-picker movements, movement of packages between workstations, and tracking other mobile devices in a manually operated warehouse. Only data that are accurate, reliable and represent the actual state of the system, are useful for detailed material flow analysis and optimization in Intralogistics. Using the developed solution, IPS technology is leveraged to enhance the manually operated warehouse operational efficiency in Intralogistics. Due to the hardware independence, the developed software solution can be used with virtually any BLE supported beacons and receivers. The results of IPS testing in laboratory/office settings show that up to 98% of passings are detected successfully with time delays between approach and detection of less than 0.5 s. Keywords: warehousing, indoor positioning systems, bluetooth low energy, particle swarm optimization, nature–inspired algorithm, intralogistics Published in DKUM: 17.08.2023; Views: 432; Downloads: 59 Full text (2,42 MB) This document has many files! More... |
6. An optimisation model for minimising totes exchange in VLM and SBS/RS integrated systemJakob Marolt, Goran Đukić, Fabio Sgarbossa, Tone Lerher, 2022, published scientific conference contribution Abstract: Warehouses and distribution centres are based on integrated material handling solutions. Most of the research papers in intralogistics are only concerned with one system to analyse and optimise the addressed system's performance, such as maximum throughput performance, minimum total cost, maximum energy efficiency, etc. This paper presents a concept to justify the proposed VLM and SBS/RS integrated system and a binary integer programming (BIP) model that minimises totes exchange between the two storage systems. The results show that the minimal number of exchanges between VLM and SBS/RS was achieved in a case study with a longer order list (T = 1600) and a highly dependent SKU's Pareto relationship (20-50). Keywords: automated warehousing, intralogistics, VLM, SBS, RS, integrated systemoptimisation, performance analysis Published in DKUM: 02.08.2023; Views: 390; Downloads: 52 Full text (743,43 KB) This document has many files! More... |
7. Object detection and graspability analysis for robotic bin-picking application in intralogisticsPrimož Bencak, Darko Hercog, Tone Lerher, 2023, published scientific conference contribution Abstract: Robotics has been gaining attention in intralogistics applications in recent years. Automation of intralogistics processes aims to cope with the rising trends of workforce deficiency, aging, and increasing demands that came with the rise of E-commerce. Many improvements aim at bin-picking applications since order-picking requires most contributions while adding little to the products' value. Robotic bin-pickers are showing promising results; however, they are still subject to many limitations. First, the vision system must correctly determine the object's location and orientation. Second, a correct robotic gripper must be chosen. Lastly, appropriate grasping points that lead to successful picking must be selected. In this paper, we explore the influencing parameters of object detection using a 3D vision system. Second, we analyze an actual bin-picking application to determine the most appropriate selection of the robotic gripper. Based on the experiments, we provide the guidelines for selecting the most appropriate robotic bin-picking configuration. Keywords: intralogistics, robotic bin-picking, detection analysis, graspability analysis Published in DKUM: 25.07.2023; Views: 407; Downloads: 27 Full text (1,89 MB) This document has many files! More... |
8. Planning and construction of the lifting and towing device of the autonomous mobile robot MiR 100 for the delivery of transport trolleys in intralogisticsTone Lerher, Aleš Belšak, Rok Skerbiš, Jure Tumpej, Žiga Volavšek, Domen Stamenov, Marko Motaln, 2022, published scientific conference contribution Abstract: Intralogistics is a very important area in warehousing and production for managing the flow of materials and informational flow. In recent years, automation and especially robotisation have had a major impact on throughput performance in intralogistics. Especially important is the transport of materials and products based on automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) with different top modules,
such as the lifting and towing device.
In this paper, planning and construction of the lifting and towing device of the autonomous mobile robot MiR 100 for the delivery of transport trolleys in intralogistics is presented. Using the engineering design methods, a new design of the lifting and towing device has been proposed and evaluated. Keywords: intralogistics, material handling systems, automation and robotisation, planning and construction, lifting and towing mechanism, simulation and animation Published in DKUM: 15.03.2023; Views: 679; Downloads: 80 Full text (1,45 MB) |
9. Evaluating robot bin-picking performance based on Box and Blocks TestPrimož Bencak, Darko Hercog, Tone Lerher, 2022, published scientific conference contribution Abstract: The rise of e-commerce, which demands solutions for small order sizes, large product assortment, short delivery times, and variable order quantity has created a need for more advanced warehousing and order-picking systems. The advancements in collaborative robotics have made it possible to automate intralogistics processes, especially the order-picking systems. If the items to be order-picked are stored in small containers, called bins, the process is known as bin-picking. The processes of bin-picking are still mainly manual due to the adaptability, dexterity, and pace of human hands. However, with the emerging technologies, the gap between human and robot dexterity is getting thinner. The integrators of robotic technologies are therefore faced with the challenge of choosing an appropriate robotic system for bin-picking. There is a lack of standardized procedures, which are designed to process such decisions easier. In our research paper, we propose an improved robotic version of the Box and Blocks Test (BBT), which provides a quick evaluation of a complete robotic bin-picking system. Using our improved robot-adapted BBT protocol, we evaluate a sample robotic bin-picking system, consisting of a collaborative robot, a 3D vision system and three types of robotic grippers, comparing the bin-picking performance of each configuration. Keywords: robotic bin-picking, intralogistics, Box, Blocks Test, vision system, collaborative robot Published in DKUM: 03.03.2023; Views: 718; Downloads: 65 Full text (715,59 KB) This document has many files! More... |
10. Simulation model for robotic pick-point evaluation for 2-F robotic gripperPrimož Bencak, Darko Hercog, Tone Lerher, 2023, original scientific article Abstract: Robotic bin-picking performance has been gaining attention in recent years with the development of increasingly advanced camera and machine vision systems, collaborative and industrial robots, and sophisticated robotic grippers. In the random bin-picking process, the wide variety of objects in terms of shape, weight, and surface require complex solutions for the objects to be reliably picked. The challenging part of robotic bin-picking is to determine object pick-points correctly. This paper presents a simulation model based on ADAMS/MATLAB cosimulation for robotic pick-point evaluation for a 2-F robotic gripper. It consists of a mechanical model constructed in ADAMS/View, MATLAB/Simulink force controller, several support functions, and the graphical user interface developed in MATLAB/App Designer. Its functionality can serve three different applications, such as: (1) determining the optimal pick-points of the object due to object complexity, (2) selecting the most appropriate robotic gripper, and (3) improving the existing configuration of the robotic gripper (finger width, depth, shape, stroke width, etc.). Additionally, based on this analysis, new variants of robotic grippers can be proposed. The simulation model has been verified on a selected object on a sample 2-F parallel robotic gripper, showing promising results, where up to 75% of pick-points were correctly determined in the initial testing phase. Keywords: intralogistics, robotic bin-picking, simulation model, ADAMS, pick-point determination, MATLAB/Simulink, 2-F robotic gripper, performance analysis Published in DKUM: 27.02.2023; Views: 764; Downloads: 104 Full text (19,99 MB) This document has many files! More... |