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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design of Station for Calculating Centre of Gravity of Truck Cabin : A Product Design Project

Bendapudi, Srinivas, Patchai Mayil Murugan, Shiva Kumar January 2018 (has links)
As a part of Linköping University’s master program course curriculum, current thesis is performed at Tools and fixtures department (MPCT) of Scania, Oskarshamn. The aim of this master thesis project is to develop a complete construction of the station in CAD which calculates the weight and center of gravity of all the different cabs produced in Scania CV AB. To accomplish this project a generic product development process described in product development textbook by Ulrich and Eppinger (2012), fifth edition and The mechanical design by David G Ullman, fourth edition were extensively used. The whole function from a black box is decomposed into several sub functions and different solutions were identified for these individual functions. By using morphology matrix and proper combinations from these solutions five different concepts were developed and presented to Scania CV AB. The team along with technical design experts in the MPCT department evaluated all the concepts and one concept was chosen for further development. Protecting the weighing scales during loading of cab from forklift onto the station and safety for the cab during tilting are the two main challenges faced during detail design phase. We were able to achieve these operations by incorporating a lifting table into the station design. Thanks to the custom made multi-tasking lift table which is manufactured and supplied by HYMO. With the help of sensors, speed of the lifting table can be controlled with two operating speeds-High & Low. Lifting table moves in its lowest speed whenever it approaches the weighing scales. Incorporation of Jacob safety into the lifting table allows the table to always operate in low speed when the lift link is in action. These sensors ensure high safety for the cab and weighing scales. Apart from this, an emergency stop has been provided to stop the entire operation in case of emergencies. In this proposed design, the center of gravity values will be determined in two stages and the weight readings are recorded in computer during these stages. For determining the longitudinal and transverse distances of CG, weight readings from all the weighing scales is essential once the cab is loaded on the station from the forklift. For determining the vertical distance of CG, two weight readings and measured tilt angle is required. A calculation module will allow the user to enter these values and obtain the result in no time. This developed 3-D CAD model with 2-D drawings are presented to Scania and the obtained results of this work fulfilled the set of requirements set for this master thesis.
2

Vliv palce nohy na stabilitu stoje a chůze / The influence of hallux on stand and gait stability

Hlinková, Zuzana January 2008 (has links)
The diploma thesis "Vliv palce nohy na stabilitu stoje a chůze" is focused on the function of hallux at stance and through the gait cycle and particularly to halluxes influence on stability of the stated motor stereotypes. The theoretical part summarizes the knowledge gained through literature research on anatomy and kinesiology of hallux. It also contains analysis of gait cycle and muscle coordination through it with emphasis upon activity of foot and function of hallux muscles. The practical part attempts to objectivize changes in stability and changes of loading of foot with instrumental examination. Force plate Balance Master® and GaitPlatform FDM were used for the measurements. On the force plate the parametres of movement of the centre of mass (COM, COG) and maintenance of stability while standing were compared. GaitPlatform® was used for measurement of ground reaction forces while standing and walking. Powered by TCPDF (www.tcpdf.org)
3

Konstrukční návrh zařízení pro měření výškové polohy těžiště vozidla / Design of a device for measuring the center of gravity height of road vehicles

Hanych, Jaroslav January 2018 (has links)
This master's thesis deals with problems connected with measuring vehicle centre of gravity height. The research part summarizes generally known methods of measuring vehicle centre of gravity and moments of inertia. Essential part of this thesis is the design of a device for measuring the centre of gravity height of a road vehicle on a principle of measuring a period of oscillation. The height position of the platform of the device is adjustable through hydraulic cylinders. A stress-strain analysis of the design was executed through a combination of analytical methods and a finite element method. The process of measurement was described and an equation for determination of centre of gravity height was deduced. Error of measurement was estimated based on the knowledge of partial errors of measured values.
4

Měření polohy těžiště vozidla / Vehicle Center of Gravity Measurement

Štěpánek, Tomáš January 2008 (has links)
This diploma thesis is devoted to problems of measurement centre of gravity position. At the beginning diploma thesis is created summary of methods to measuring moment of inertia and position measuring of centre of gravity of vehicle. Proposal is in-process on the basis method weighing on oblique position. And measurement is possible in Institute of automotive engineering in Brno. Is proposed measuring platform and preparative for obstruct changes of centre of gravity position at measuring. Measuring procedure is described and is derived formula toward calculation position of gravity centre of vehicle. To troubleshooting parts of platform are elaborate solidity calculations. In final parts diploma thesis are mentioned results from these measurements. Drawing documentation of platform and programme for calculation of centre of gravity of vehicle is enclosed in diploma thesis.
5

Měření výškové polohy těžiště vozidla / Measurement of Vehicle CG Height Position

Fedra, Tomáš January 2010 (has links)
This diploma thesis deals with measurement of vehicle centre of gravity height position. All methods for measurement of CG height position are described in the first part. The second part deals with designing of device for measurement of CG height. This measurement device is analysed by Finite Element Method. The vehicle is tilt by hydraulic system. The third part shows the best tilt angle for minimal error of CG height. At the end, there is described a measuring procedure for designed device.
6

Měření polohy těžiště jízdních kol / Center of Gravity Measurements of Bicycles

Burda, Ondřej January 2012 (has links)
The first part of the thesis The measurement of the location of centre of gravity of bicycles is firstly about history and division of bicycles, about the legislation in the Czech Republic concerning the cyclists, about the analysis of accidents of cyclists and lastly about the analysis of the method of the measurement of the location of centre of gravity. The second part of the thesis describes the procedure of calculation of the location of centre of gravity in the chosen incline method and the proposal of measure apparatus. The third part of the thesis occupies with the measurement and processing of concrete values for chosen sample of cyclists on the bicycles which are selected in the way that the results of the location of centre of gravity in the final part of the thesis are compared with the respect to their application during the expert opinion.
7

Frequency Analysis of Rottne Comfort Line

Grzeszczak, Jan, Płygawko, Michał January 2014 (has links)
The European Parliment stipulated regulations concerning the forestry vehicles operators' health and working conditions. The allowed whole body vibrations were limited, which influenced the design of the vehicles' cabin. Surveys show a strong correlation between operator's comport and their productivity. The object of the research was Rottne AB Comfort Line Cabin, which was designed to increase the comfort for the forwarder operators. The main objective was to determine the cab's inertia properties, position of the centre of gravity and the resonance frequencies of the cab as well as a system consisting of the cab and its suspension. The methods used were an impact test with Mass-Line Analysis for the cab's properties and Operational Modal Analysis for the system. For both tests a Leuven Measurement System was used, but a part of the calculations were made in parallel by use of a MATLAB code written for this thesis. In addition a suspension test was made to estimate the centre of gravity and it was here treated as the reference value. The authors used reference values and the quality of the obtained results to compare the methods used. Further proposals for future research were made together with hints how to use vibration tests more effectively.
8

Návrh zařízení pro měření výškové polohy těžiště automobilu / Design of Device for Vehicle Center of Gravity Height Measurement

Rektořík, Jiří January 2017 (has links)
The objective of this diploma thesis is the design of a device that measures the vehicle’s centre of gravity height position. The first part defines individual methods of measurement using various measuring equipment. The next part deals with the definition of requirements for the device and the definition of the design. A stress-strain analysis was executed for selected components. This diploma thesis describes the preparation process of the vehicle and the device for the measurement. The next part is dedicated to the design of the measuring chain and to the evaluation of the results. The thesis concludes with a theoretic analysis of the measurement inaccuracy.
9

Zařízení pro měření výškové polohy těžiště vozidla / Device for measuring the centre of gravity height position of road vehicle

Kubica, Petr January 2015 (has links)
This diploma thesis deals the with measurment of the centre of gravity height position of a road vehicle and its issues. The introduction of this thesis focuses on the determining of the position of the center of gravity and the moment of inertia of a road vehicle. The next part is about creationing of a construction plan and its verification. The thesis contains a sensitivity analysis of this device including its results. The end of the thesis informs about the executed measurment in a laboratory and about recommendations for next measurments.
10

Fault tolerant adaptive control of an unmanned aerial vehicle

Basson, Willem Albertus 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: This thesis presents the development of an adaptive longitudinal control system for an unmanned aerial vehicle (UAV). The project forms part of a research effort at Stellenbosch University into different fault-tolerant control techniques for UAVs. In order to demonstrate the usefulness of fault-tolerant adaptive control, the control system was designed to handle damage-induced longitudinal shifts in the centre of gravity (CG) of the aircraft, which are known to have a dramatic effect on the stability of a fixed-wing aircraft. Using a simplified force and moment model, equations were derived which model the effect of longitudinal CG shifts on the behaviour of the aircraft. A linear analysis of the longitudinal dynamics using these equations showed that the short period mode can become unstable for backward CG shifts. An adaptive pitch rate controller with the model reference adaptive control structure was designed to re-stabilise the short period mode when the CG shifts backwards. The adaptive law was designed using Lyapunov stability theory. Airspeed, climb rate and altitude controllers were designed around the pitch rate controller to allow full autonomous control of the longitudinal dynamics of the UAV. These outer loops were designed with constant parameters, since they would be unaffected by CG shifts if the adaptive pitch rate controller performed as desired. Pure software simulations as well as hardware-in-the-loop simulations showed that the adaptive control system is able to handle instantaneous shifts in the centre of gravity which would destabilise a fixed-gain control system. These simulation results were validated in flight tests, where the aircraft was destabilised using positive feedback and re-stabilised by the adaptive control system. Thus the simulation and flight test results showed that an adaptive control can re-stabilise an unstable aircraft without explicit knowledge of the change in the aircraft dynamics, and therefore could be effective as part of an integrated fault-tolerant control system. / AFRIKAANSE OPSOMMING: Hierdie tesis bied die ontwikkeling aan van ’n aanpassende longitudinale beheerstelsel vir ’n onbemande vliegtuig. Die projek is deel van navorsing by die Universiteit van Stellenbosch oor verskillende fout-tolerante beheertegnieke vir onbemande vliegtuie. Om die doeltreffendheid van aanpassende beheer te demonstreer, is die beheerstelsel ontwerp om situasies te kan hanteer waar die vliegtuig só beskadig word dat sy massamiddelpunt agtertoe skuif, wat ’n groot invloed op die stabiliteit van ’n vastevlerk-vliegtuig kan hê. ’n Vereenvoudigde model van die kragte en momente wat op die vliegtuig inwerk is gebruik om vergelykings af te lei wat beskryf hoe die gedrag van die vliegtuig verander as die massamiddelpunt agtertoe verskuif. Hierdie vergelykings is gebruik in ’n lineêre analise van die longitudinale dinamika van die vliegtuig, wat getoon het dat die kortperiode-modus onstabiel kan raak as die massamiddelpunt agtertoe verskuif. ’n Aanpassende heitempobeheerder met die modelverwysings-aanpassende beheerstruktuur is ontwerp om die kortperiode-modus weer te stabiliseer wanneer die massamiddelpunt agtertoe verskuif. Die aanpassingswet is ontwerp deur die gebruik van Lyapunov se stabiliteitsteorie. Lugspoed-, klimtempo- en hoogtebeheerders is rondom die aanpassende heitempobeheerder ontwerp sodat die longitudinale dinamika van die vliegtuig heeltemal outonoom beheer kan word. Hierdie buitelusse is ontwerp met vaste parameters, aangesien hulle nie geraak sal word deur verskuiwings in die massamiddelpunt as die aanpassende heitempobeheerder na wense werk nie. Suiwer sagteware-simulasies, sowel as hardeware-in-die-lus-simulasies, het getoon dat die aanpassende beheerstelsel oombliklike verskuiwings in die massamiddelpunt goed kan hanteer, waar sulke verskuiwings ’n beheerstelsel met vaste parameters onstabiel sou maak. Hierdie simulasie-resultate is bevestig deur vlugtoetse te doen, waar die vliegtuig onstabiel gemaak is deur positiewe terugvoer, en weer deur die aanpassende beheerstelsel stabiel gemaak is. Die simulasie- en vlugtoetsresultate wys dus dat aanpassende beheer ’n onstabiele vliegtuig weer kan stabiliseer sonder eksplisiete kennis van die veranderinge in die dinamika van die vliegtuig. Aanpassende beheer kan dus doeltreffend wees as deel van ’n geïntegreerde fout-tolerante beheerstelsel.

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