Global ETD Search

1	Dynamic Modelling Of A Backhoe-loader Kilic, Boran 01 September 2009 (has links) (PDF) The aim of this study is to develop a dynamic model of the loader system of a backhoe-loader. Rigid bodies and joints in the loader mechanism and loader hydraulic system components are modelled and analyzed in the same environment using the physical modelling toolboxes inside the commercially available simulation software, MATLAB/Simulink. Interaction between the bodies and response of the hydraulic system are obtained by co-operating the mechanical and hydraulic analyses. System variables such as pressure, flow and displacement are measured on a physical machine and then compared with the simulation results. Simulation results are consistent with the measurement results. The main result of this work is the ability to determine the dynamic loads on the joints and attachments of the backhoe-loader. In addition to that, prototyping time and costs can be highly reduced by implementing this model in the design process. TJ Hydraulic Machinery 836-927
2	Optimization Of Backhoe-loader Mechanisms Ipek, Levent 01 October 2006 (has links) (PDF) This study aims to develop a computer program to optimize the performance of loader mechanisms in backhoe-loaders. The complexity and the constraints imposed on the loader mechanism does not permit the use of classical optimization techniques used in the synthesis of mechanisms. Genetic algorithm is used to determine the values of the design parameters of the mechanism while satisfying the constraints and trying to maximize breakout forces that the machine can generate. TJ Hydraulic Machinery 836-927
3	Ride Model And Simulation Of A Backhoe-loader Goztas, Durmus Ali 01 January 2010 (has links) (PDF) The objective of this study is to present a dynamic model of a backhoe-loader including cab dynamics in order to simulate the vibration levels transmitted to the operator. For this purpose, analytical solutions of the cab and the machine are developed by deriving the equations of motion of the system and the state space forms of the solution are implemented in the commercially available simulation software, MATLAB/Simulink. In addition to the analytical solution, a model is developed using the physical modeling toolboxes of MATLAB/SimMechanics. Cab model developed in SimMechanics is extended to simulate whole machine dynamics by inserting machine body and tire parameters. Vibration data is acquired from the machine for experimental validation of the models. Analytical and SimMechanics solution are evaluated by comparing the seat acceleration results for the same inputs. Furthermore, simulation results obtained from the models and the measurement results are found to be in agreement in both time and frequency domain.
4	Load Unit Geometry Optimization for Heavy Duty Machinery Samuelsson, Ted January 2015 (has links) The construction equipment industry is developing at a fast pace, increasing the expectation on the next-generation machines. Wheel loaders and backhoe loaders are part of this evolution and all subsystems in those machines need to be developed to meet the high demands in energy eciency and productivity. One of the most important parts of the wheel loader is the loading unit. This is traditionally designed using highly experienced engineers and CAD software. To simplify the early stages of this process was an optimization tool developed to generate a design outlay. The optimization will minimize the mass of the linkage since unnecessary weight will lower the eciency. The minimum can be found by moving the joints and adjusting the shape of the device. The optimization will also include constraints to assure the correct performance of the linkage. Since there are a high number of design variables, a gradient-based optimization method was used. A finite element solver was also implemented to calculate the forces and stresses in the linkage. The linkages studied in this report are one from a typical wheel loader and one from a backhoe loader. Since these machines are extremely versatile, and used formany diferent tasks, two sets of constraints are compiled. One of the constraint sets yields a linkage suitable for machines only equipped with bucket, while the other results in an all-round linkage suitable for most tools and applications. The optimized linkages are compared to existing devices. The results show that there are some improvements possible and that the software could be used to help designers. However, the optimization problem is hard to solve due to non-smooth constraints functions and numerical instabilities. This issue could be overcome by diferent means, like using automatic diferentiation, a non-gradient based optimization method, decreasing the number of constraints or decreasing the number of design variables. / Utvecklingen av anlaggningsmaskiner sker i snabb takt och detta ökar förväntningarna på framtidens maskiner. En stor andel av alla anläggningsmaskiner är hjullastare och traktorgrävare och alla delsystem på dessa maskiner måste följa med i utvecklingen. En av de viktigaste delarna pa en hjullastare ar lastaggregatet. Det designas traditionellt med hjälp av CAD mjukvara och mycket erfarna konstruktörer. För att underlätta denna process har en optimeringsrutin utvecklats, som generarar ett designförslag. Optimeringen minskar länkagets massa genom att fytta lagringspositioner och ändra delarnas dimensioner. Detta ökar efektiviteten hos maskinen eftersom den slipper köra runt på onödig vikt. Optimeringen innehåller även villkor för att säkerställa god prestanda hos det optimerade aggregatet. Eftersom det ingår väldigt många designvariabler i optimeringen används en gradientbaserad metod. En finita element approximation används for att beräkna krafter och spänningar i länkaget. De länkage som undersöks i detta projekt är ett typsikt hjullastaraggregat och ett typiskt traktorgrävaraggregat. Eftersom dessa maskiner ar väldigt mångsidiga sammanställdes två olika uppsättningar av villkor. Den ena uppsättningen används för att optimera ett aggregat som endast ska användas med skopa, medan den andra uppsättningen används för att ta fram ett mer mångsidigt aggregat avsätt for att kunna klara av de flesta situationer och verktyg. De optimerade lastaggregaten är jämförda med produktionsaggregat och det visar sig att vissa förbättringar är möjliga. Slutsattsen är att optimeringsrutinen kan bli ett bra hjälpmedel for konstruktörer men att den behöver lite mer veriering. Villkorsfunktionen som optimeringen måste lösa är inte helt slät vilket är ett problem för en gradientbaserade metod och dessutom finns vissa numeriska instabiliteter. Dessa svårigheter kan undkommas pa olika sätt, t.ex. genom att använda automatisk derivering,byta optimeringsalgoritm, minska antalet villkor eller minska antalet variabler. Design Optimization Geometry Optimization Finite Element Method (FEM) Gradient Based Optimization Wheel Loader Backhoe Loader
5	Vysokovýklopná lopata / High loading shovel Petro, Roman January 2009 (has links) This diploma thesis solves construction project high dumping shovel for back hoe loader New Holland B100 and B110. There are described operating conditions in the introduction, transport material and technical parameters for back hoe loader B100, B110. There are mentioned possible construction’s solutions and own design. Follow the kinematics analysis of material’s dumping and the static analysis on shovel and frame. This is connected with following peg’s control and the solidity analysis of shovel and frame for different load cases, where the MFE was used
6	Výstavba školy Rajhrad – stavebně technologická příprava / Construction of school Rajhrad – construction and technological preparation Kijonka, Jakub January 2012 (has links) Subject of this master thesis is the structural and technological background for the construction of high school in Rajhrad. This consists of time and finanical plans, technological instructions for the reinforced concrete monolithic skeleton, time schedule, item budget, construction site layout, machinery configuration , audit and evaluation plans, work place safety protocols, environmental plan of the construction site.
7	Placement of Controls in Construction Equipment Using Operators´Sitting Postures : Process and Recommendations Jalkebo, Charlotte January 2014 (has links) An ergonomically designed work environment may decrease work related musculoskeletal disorders, lead to less sick leaves and increase production time for operators and companies all around the world. Volvo Construction Equipment wants to deepen the knowledge and investigate more carefully how operators are actually sitting whilst operating the machines, how this affects placement of controls and furthermore optimize controls placements accordingly. The purpose is to enhance their product development process by suggesting guidelines for control placement with improved ergonomics based on operators’ sitting postures. The goal is to deliver a process which identifies and transfers sitting postures to RAMSIS and uses them for control placement recommendations in the cab and operator environments. Delimitations concerns: physical ergonomics, 80% usability of the resulted process on the machine types, and the level of detail for controls and their placements. Research, analysis, interviews, test driving of machines, video recordings of operators and the ergonomic software RAMSIS has served as base for analysis. The analysis led to (i) the conclusion that sitting postures affect optimal ergonomic placement of controls, though not ISO-standards, (ii) the conclusion that RAMSIS heavy truck postures does not seem to correspond to Volvo CE’s operators’ sitting postures and (iii) and to an advanced engineering project process suitable for all machine types and applicable in the product development process. The result can also be used for other machines than construction equipment. The resulted process consists of three independent sub-processes with step by step explanations and recommendations of; (i) what information that needs to be gathered, (ii) how to identify and transfer sitting postures into RAMSIS, (iii) how to use RAMSIS to create e design aid for recommended control placement. The thesis also contains additional enhancements to Volvo CE’s product development process with focus on ergonomics. A conclusion is that the use of motion capture could not be verified to work for Volvo Construction Equipment, though it was verified that if motion capture works, the process works. Another conclusion is that the suggested body landmarks not could be verified that they are all needed for this purpose except for those needed for control placement. Though they are based on previous sitting posture identification in vehicles and only those that also occur in RAMSIS are recommended, and therefore they can be used. This thesis also questions the most important parameters for interior vehicle design (hip- and eye locations) and suggests that shoulder locations are just as important. The thesis concluded five parameters for control categorization, and added seven categories in addition to those mentioned in the ISO-standards. Other contradictions and loopholes in the ISO-standards were identified, highlighted and discussed. Suggestions for improving the ergonomic analyses in RAMSIS can also be found in this report. More future research mentioned is more details on control placement as well as research regarding sitting postures are suggested. If the resulted process is delimited to concern upper body postures, other methods for posture identification may be used. Motion capture controls placement posture identification construction equipment operator environment volvo ce depth sensor inertial optical zone of reach zone of comfort H-point SIP Seat index point product development ergonomics Work Related Musculoskeletal Disorders Human Machine Interaction HMI WRMD Anthropometry Catia RAMSIS GEometric Kinematic backhoe loader wheel loader articulated hauler excavator Faro-Arm CMM Skeleton points skin points sitting posture operating posture categorization V model visual fields percentile road condition skill level sight point Abrasion speed visibility FOV field of view primary secondary tertiary ZoC ZoR mid-eye Design aid safety heavy truck

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