Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2002. / Field problem. Includes bibliographical references.

published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

Predmetom tejto diplomovej práce je design elektrického štvorkolesového vysokozdvižného vozíka zameraný na inovatívny prístup k návrhu s technickými, estetickými, ergonomickými a ekologickými požiadavkami. Cieľom designu je navrhnúť koncepciu inovatívneho stroja, ktorý bude charakteristický vysokou estetickou kvalitou. Vysokozdvižné vozíky sú spravidla hodnotené z pohľadu ich základných charakteristík, ktorými sú kompaktnosť, manévrovateľnosť, výška zdvihu, stabilita a nosnosť

To meet the increasing demand on control precision in industrial forklifts, physical modelling of the lifting system has been combined with parameter estimations from data. A number of different controllers have been evaluated in terms of their ability to achieve a load independent lifting speed. The model and controller performance as well as stability properties were evaluated in simulations, and the most promising controller was implemented on the real system. Especially the electric motor turned out to be difficult to model, and therefore experimental data was used to approximate some parts of it. This, along with some friction parameters that had to be estimated caused a slight loss in model generality. An observer (Extended Kalman filter) was used to estimate the unknown states, including the velocity of the forks. The simulated performance of the MPC controller was slightly better than the PID controller, except for a bigger overshoot when starting from a turned off motor. The PID controller also handles model errors better, because of its integral action. Due to the simplicity in relation to performance, only the PID controller was implemented on the forklift. The model turned out to perform well, but not well enough to estimate the lifting height accurately. The PID controller worked as intended and it could therefore be concluded that a more advanced control algorithm, such as an MPC controller, is not necessary for this system.

ABSTRACT Carton Clamp Test Methodologies and the Effects on Load Containment and Retention Tyler Don Blumer A carton clamp is an alternative device for moving packages and material. Instead of using iron tines like that of a conventional forklift, a carton clamp uses two large aluminum platens to slightly compress and secure the load for handling. This is advantageous as it allows operators to move layers of a unitized load individually, and eliminates the need for a pallet when handling full unitized loads. When using a carton clamp attachment, it is often difficult for operators to accurately gauge the amount of force being applied to the load. The required clamping force changes depending on the size, shape, and weight of the load. This creates the potential for under-clamping (slippage) and over-clamping (compressive damage). Seeing a market need for a reliable means of testing, two organizations set out to develop a testing protocol. A rift formed between schools of thought regarding the correct testing procedure. ISTA provides a sterile, calculated, and stationary simulation of carton clamp handling in its ISTA 6-SAMS test protocol. ASTM offers a more holistic, dynamic, observational approach in its mobile ASTM 6055 standard protocol. One school of thought is suggested to imply that a package should be developed to be handled by the carton clamp (ASTM). The other school of thought is that the carton clamp attachment should be properly adjusted to the package specimen (ISTA). Previous studies have been performed citing the ISTA standard and using a specialized carton clamping device vibration device that is calibrated for laboratory research. Arguably, this method, though repeatable in nature, does not accurately simulate carton clamp handling found in industry. Likewise, the equipment investment is cost prohibitive for those in industry wishing to duplicate such a study. ASTM uses a carton clamp truck as used in industry, but does not specify any specific parameters making repeatability between laboratories and practitioners ambiguous. This study examined whether or not a common ground can be reached; implementing a carton clamp lift truck as found in industry allowing for mobile (hazard course) testing. A modified version of ISTA 3B will be paired off against ASTM 6055 for evaluating both column and cross stack pallet patterns with a variety of treatments. This study attempted to determine if carton clamps as found in industry are capable and repeatable enough to provide consistent data. Similarly, this study examined the test methodologies effect on load containment via stretch film force, load retention via unitized load slippage, and the effects of ride height and driver interaction. The study sought to understand if these effects are uniform across the unitized load, or if particular layers of the load more affected than others.

Pallets play a crucial role in the supply chain with approximately 2.6 billion in circulation in the United States alone. Although often overlooked, pallets can become costly for a company if not designed correctly for their specific supply chain. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. Forklifts are the dominant mode of material handling for palletized products, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic nature of forklifts in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert during material handling. Forklifts in multiple facilities were instrumented with Lansmont SAVER 3X90 and 3D15 data loggers to measure the acceleration peak, g of shock impacts, duration of impacts, random vibration intensity and RMS (g) values during forklift handling in the field. The highest vibration levels were observed for distribution facilities with an average acceleration (peak, g) of 0.353 g. Based on the results of the vibration data collection, the vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that LTL facilities recorded the highest average shock impact of all the facilities investigated, with an average acceleration value of 4.74 g with an average shock duration of 7.42 msec. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains. / Master of Science / With 2.6 billion pallets in circulation within the United States alone, pallets play a significant role in the supply chain. Pallets can become costly for a company if not designed correctly for their specific supply chain, so it is important not to overlook a pallet. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. The forklift is the most common mode of material handling for the transportation of palletized products within a warehousing system, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic shock and vibration characteristics that forklifts experience in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert on pallets during material handling. Forklifts in multiple facilities were instrumented with Lansmont data loggers to measure the dynamic characteristics of both shock and vibration in the field. The highest vibration levels were observed for distribution facilities. Based on the results of the vibration data collection, a vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that Less-than-Truckload (LTL) facilities recorded the highest average shock impact of all the facilities investigated. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains.

The basis of the study lies with a newly patented gearbox by cardiologist and inventor Stig Lundbäck. Stig founded CorPower Ocean AB to further develop the gearbox to be used in a wave energy device. The purpose of this project is to develop a concept of a lifting system with CorPower Oceans gearbox that is more energy efficient than a hydraulic lifting system. The goal is to use technology from CorPower Oceans gearbox inversely to perform heavy lifting as an alternative to hydraulics. The project is limited to applying the gearbox and gear rack on a forklift with a lifting capacity of ten tons.The main tool in this project will be the product development process Systems Engineering where only the most relevant parts will be used to develop a concept. Calculations of the strength and dimensions of the gear racks are made to ensure the possibility of this solution.

The project elaborated proposal of comprehensive monitoring of the forklift reconditioning process at the regional refurbishment center for central and east Europe. The proposal aims to increase overall customer satisfaction. The choice of the specific form of monitoring was based on theoretical background and process analysis. Monitoring of process activities is carried out on the basis of barcodes and scanning devices, which are able to distinguish the date and specific time. The proposal results are an overall customer overview increase within process, customer satisfaction increase and support improvement of managing and decision making.

Warehouses are essential for any logistical operation, and Forklifts are efficient tools for moving products and pallets inside warehouses. Forklifts are also heavy machines that are prone to inflict damage on pallets and goods. The demand for forklift operators increases with the demand for forklifts. Inexperienced forklift operators must be equipped with the right tools to carry out everyday tasks with minimum damage. This thesis focuses on investigating the damages that occur by forklifts in warehouse settings, and what measures that can be taken to reduce the damages. Contrary to existing literature that explores damages from the perspective of packaging technology, this study explores how damages happen and how they can be mitigated from the forklift's point of view. The investigation took part in a warehouse that carry out operations for a large furniture manufacturer. A case study was conducted and two major damage types were identified: puncture damages and impact damages, and the most common cause for the occurrence of these damages is the lack of visibility. The case study was followed by a design process to find a solution that fits the end users. The final concept takes form as a system solution, consisting of a sensor-based system that assists the forklift operator during loading and unloading. Along with this, a bumper was developed to mitigate the damage inflicted on goods during handling of goods. / Varulager är avgörande för all logistisk verksamhet. Gaffeltruckar är effektiva verktyg för att flytta produkter och pallar inuti varulager. Gaffeltruckar är dock tunga maskiner som är benägna att orsaka skador på både pallar och gods. Efterfrågan på gaffeltruckförare ökar tillsammans med efterfrågan på gaffeltruckar. Oerfarna truckförare måste vara utrustade med rätt verktyg för att utföra dagliga uppgifter med minimala skador. Detta examensarbete fokuserar på att undersöka de skador som sker på grund av gaffeltruckar i lagermiljöer, och vilka åtgärder som kan vidtas för att minska skadorna. Till skillnad från befintlig litteratur som utforskar skador ur förpackningsteknologins perspektiv, undersöker denna studie hur skador uppstår och hur de kan minskas från en gaffeltrucks synvinkel. Utredningen tog plats i ett lager som bedriver verksamhet åt en stor möbeltillverkare. En fallstudie genomfördes och två primära skadetyper identifierades: punkteringsskador och slagskador, och den vanligaste orsaken till att dessa skador uppstår är bristen på sikt. Fallstudien följdes av en designprocess för att hitta en lösning som passar slutanvändarna. En produktutvecklingsprocess resulterade i en systemlösning, bestående av ett sensorbaserat system som hjälper truckföraren vid lastning och lossning. Tillsammans med detta utvecklades en stötfångare för att mildra skadorna på gods vid godshantering.

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