Global ETD Search

11	Modeling, Design and Control of Multiple Low-Cost Robotic Ground Vehicles January 2015 (has links) abstract: Toward the ambitious long-term goal of a fleet of cooperating Flexible Autonomous Machines operating in an uncertain Environment (FAME), this thesis addresses several critical modeling, design and control objectives for ground vehicles. One central objective was to show how off-the-shelf (low-cost) remote-control (RC) “toy” vehicles can be converted into intelligent multi-capability robotic-platforms for conducting FAME research. This is shown for two vehicle classes: (1) six differential-drive (DD) RC vehicles called Thunder Tumbler (DDTT) and (2) one rear-wheel drive (RWD) RC car called Ford F-150 (1:14 scale). Each DDTT-vehicle was augmented to provide a substantive suite of capabilities as summarized below (It should be noted, however, that only one DDTT-vehicle was augmented with an inertial measurement unit (IMU) and 2.4 GHz RC capability): (1) magnetic wheel-encoders/IMU for(dead-reckoning-based) inner-loop speed-control and outer-loop position-directional-control, (2) Arduino Uno microcontroller-board for encoder-based inner-loop speed-control and encoder-IMU-ultrasound-based outer-loop cruise-position-directional-separation-control, (3) Arduino motor-shield for inner-loop motor-speed-control, (4)Raspberry Pi II computer-board for demanding outer-loop vision-based cruise- position-directional-control, (5) Raspberry Pi 5MP camera for outer-loop cruise-position-directional-control (exploiting WiFi to send video back to laptop), (6) forward-pointing ultrasonic distance/rangefinder sensor for outer-loop separation-control, and (7) 2.4 GHz spread-spectrum RC capability to replace original 27/49 MHz RC. Each “enhanced”/ augmented DDTT-vehicle costs less than 􀀀175 but offers the capability of commercially available vehicles costing over 􀀀500. Both the Arduino and Raspberry are low-cost, well-supported (software wise) and easy-to-use. For the vehicle classes considered (i.e. DD, RWD), both kinematic and dynamical (planar xy) models are examined. Suitable nonlinear/linear-models are used to develop inner/outer-loopcontrol laws. All demonstrations presented involve enhanced DDTT-vehicles; one the F-150; one a quadrotor. The following summarizes key hardware demonstrations: (1) cruise-control along line, (2) position-control along line (3) position-control along curve (4) planar (xy) Cartesian stabilization, (5) cruise-control along jagged line/curve, (6) vehicle-target spacing-control, (7) multi-robot spacing-control along line/curve, (8) tracking slowly-moving remote-controlled quadrotor, (9) avoiding obstacle while moving toward target, (10) RC F-150 followed by DDTT-vehicle. Hardware data/video is compared with, and corroborated by, model-based simulations. In short, many capabilities that are critical for reaching the longer-term FAME goal are demonstrated. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015 Electrical engineering Robotics cruise control differential-drive hierarchical inner-outer loop control Mobile robots obstacle avoidance rear wheel drive
12	Automation and synchronizationof traction assistance devices toimprove traction and steerability ofa construction truck Dabhi, Meet, Vaidyanathan, Karthik Ramanan January 2017 (has links) Automotive development has always been need-based and the product of today is an evolutionover several decades and a diversied technology application to deliver better products to theend users. Steady increase in the deployment of on-board electronics and software is characterizedby the demand and stringent regulations. Today, almost every function on-board a modernvehicle is either monitored or controlled electronically.One such specic demand for AB Volvo arose out of construction trucks in the US market. Usersseldom have/had a view of the operational boundaries of the drivetrain components, resultingin inappropriate use causing damage, poor traction and steering performance. Also, AB Volvo'sstand-alone traction assistance functions were not suciently capable to handle the vehicle useconditions. Hence, the goal was set to automate and synchronize the traction assistance devicesand software functions to improve the traction and steerability under a variety of road conditions.The rst steps in this thesis involved understanding the drivetrain components from design andoperational boundary perspective. The function descriptions of the various traction softwarefunctions were reviewed and a development/integration plan drafted. A literature survey wascarried out seeking potential improvement in traction from dierential locking and also its eectson steerability. A benchmarking exercise was carried out to identify competitor and suppliertechnologies available for the traction device automation task.The focus was then shifted to developing and validating the traction controller in a simulationenvironment. Importance was given to modeling of drivetrain components and renement ofvehicle behavior to study and understand the eects of dierential locking and develop a differentiallock control strategy. The modeling also included creating dierent road segments toreplicate use environment and simulating vehicle performance in the same, to reduce test timeand costs. With well-correlated vehicle performance results, a dierential lock control strategywas developed and simulated to observe traction improvement. It was then implemented onan all-wheel drive construction truck using dSPACE Autobox to test, validate and rene thecontroller.Periodic test sessions carried out at Hallered proving ground, Sweden were important to re-ne the control strategy. Feedback from test drivers and inputs from cross-functional teamswere essential to develop a robust controller and the same was tested for vehicle suitability andrepeatability of results. When comparing with the existing traction software functions, the integrateddierential lock and transfer case lock controller showed signicantly better performanceunder most test conditions. Repeatable results proved the reliability of developed controller.The correlation between vehicle test scenarios and simulation environment results indicated theaccuracy of software models and control strategy, bi-directionally.Finally, the new traction assistance device controller function was demonstrated within ABVolvo to showcase the traction improvement and uncompromising steerability. All-wheel drive Control strategy Dierential lock control Drivetrain Modeling Simulation Steerability Traction Vehicle performance Engineering and Technology Teknik och teknologier
13	Porovnání jízdních vlastností vozidel / Comparison of Vehicle Handling Characteristics Kalábová, Barbora January 2013 (has links) This thesis deals with the analysis of the car driving characteristics depending on the type of drive wheels. The first chapter defines the basic theoretical cars concept as well as procedures for determining the individual variables needed to identify the driving dynamics of vehicles. The practical part describes the plan and the progress of realized measurements on a selected pattern of vehicles, and the measured values are interpreted. The final part deals with the evaluation of the performed measurements and the data identified within these measurements.
14	Beitrag zur Integration eines elektrischen Einzelradantriebes in eine Landmaschine Geißler, Mike 21 February 2017 (has links) (PDF) Am Beispiel einer Landmaschine wurde die Integration eines dieselelektrischen Einzelradantriebes unter der Berücksichtigung der spezifischen Anforderungen nachgewiesen. Die Integration des elektrischen Antriebes in die Fahrzeugfelge führt zu einem abgeschlossenen System mit definierten Schnittstellen. Zur Umsetzung des Antriebssystems werden unterschiedliche Lösungen diskutiert und die Vorzugsvariante realisiert. Für das Antriebssystem und das Fahrzeug werden die Funktionsnachweise mittels Simulationsergebnissen, Prüfstands- und Fahrversuchen erbracht. Ebenso wird der Nutzen eines elektrischen Einzelradantriebssystems diskutiert. Landmaschine mobile Maschine elektrischer Antrieb Radanbtrieb Radnabenantrieb dieselelektrisch Rigitrac mobile Machinery agricultural machine electric drive wheel drive hub diesel electric Rigitrac ddc:620 rvk:ZD 72200
15	Desenvolvimento de um controlador híbrido Fuzzy-PID para estabilização de um VANT do tipo quadrirrotor na realização de um voo autônomo vertical Morais, Edpo Rodrigues de 17 February 2017 (has links) Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-06-29T22:59:45Z No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Rejected by Vanessa Christiane (referencia@ufersa.edu.br), reason: Corrigir referência. on 2017-07-03T12:21:49Z (GMT) / Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-04T14:22:25Z No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:48:02Z (GMT) No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:58:07Z (GMT) No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Made available in DSpace on 2017-07-04T17:03:31Z (GMT). No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) Previous issue date: 2017-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation proposes the development of a Fuzzy-PID hybrid controller for the height stability control of a four-engine type UAV. The work also contemplates the development of a classical PID controller, used to compare with the hybrid one purposed. The AuRoRA platform is used for the realization of tests with both of the control structures, being this one provided with the parameters of the Drone used. With the test results, it was possible to conclude that both of the controllers, the classical PID and the Fuzzy-PID, are able to perform the Drone height control, and the hybrid control obtained some advantages such as the ability of self-adjust with the system variation, that dispenses the manual tuning of the gains, besides presenting an improvement in the Drone height stability / Esta dissertação propõe o desenvolvimento de um controlador híbrido Fuzzy-PID para o controle de estabilidade de altura de um VANT do tipo quadrirrotor. O trabalho ainda contempla o desenvolvimento de um controlador PID clássico, utilizado para fins de comparação com o controlador híbrido proposto. A plataforma AuRoRA é utilizada para a realização dos testes com ambas as estruturas de controle, sendo a mesma munida dos parâmetros do Drone utilizado. Com os resultados dos testes, foi possível verificar que ambos controladores, PID clássico e Fuzzy-PID, são capazes de realizar o controle de altura do Drone, tendo o controle híbrido obtido algumas vantagens como a capacidade de auto ajuste mediante variações no sistema, o que dispensa as sintonias manuais dos ganhos, além de apresentar uma melhoria na estabilidade da altura do Drone / 2017-06-29 Quadrirrotor Controle híbrido Fuzzy-PID Controle PID Voo vertical Estabilização de altura Four-wheel drive Fuzzy-PID hybrid controller PID control Vertical flight Height stabilization CNPQ::CIENCIAS EXATAS E DA TERRA
16	Beitrag zur Integration eines elektrischen Einzelradantriebes in eine Landmaschine Geißler, Mike 07 December 2016 (has links) Am Beispiel einer Landmaschine wurde die Integration eines dieselelektrischen Einzelradantriebes unter der Berücksichtigung der spezifischen Anforderungen nachgewiesen. Die Integration des elektrischen Antriebes in die Fahrzeugfelge führt zu einem abgeschlossenen System mit definierten Schnittstellen. Zur Umsetzung des Antriebssystems werden unterschiedliche Lösungen diskutiert und die Vorzugsvariante realisiert. Für das Antriebssystem und das Fahrzeug werden die Funktionsnachweise mittels Simulationsergebnissen, Prüfstands- und Fahrversuchen erbracht. Ebenso wird der Nutzen eines elektrischen Einzelradantriebssystems diskutiert.:1 Einleitung 2 Stand der Forschung und Entwicklung bei Fahrzeugantrieben und elektrischen Antriebssystemen 2.1 Allgemeine Entwicklungstendenzen der Antriebssysteme bei mobilen Landmaschinen . 2.2 Meilensteine elektrischer Antriebssysteme 2.3 Fahrantriebe für mobile Landmaschinen 2.4 Übersicht zu elektrischen Antrieben in mobilen Maschinen 2.5 Elektrische Antriebe für Fahrantriebe 2.6 Leistungselektronik für den mobilen Einsatz 2.7 Anpassen der Motorenkennlinie an das Kennfeld des Fahrantriebs 2.8 Elektrische Zusatzkomponenten 3 Konzeption und Entwicklung eines Einzelradantriebes 3.1 Spezifische Anforderungen an den dieselelektrischen Fahrantrieb 3.2 Systementwurf 3.3 Methodik und Entwurf des Einzelradantriebes 3.4 Entwicklung des Einzelradantriebes 3.5 Entwicklung der Wicklungsumschaltung 4 Untersuchungen und Ergebnisse zur Wicklungsumschaltung und der elektrischen Maschine 4.1 Simulationsmodell der Wicklungsumschaltung 4.2 Simulationsergebnisse der Wicklungsumschaltung 4.3 Prüfstandsergebnisse von Wicklungsumschaltung und elektrischer Maschine 5 Integration eines Einzelradantriebes am Beispiel eines Bergtraktors 5.1 Vorstellung des Experimentalaufbaus 5.2 Simulationsmodell der Fahr- und Antriebsdynamik und des Rad-Boden-Kontaktes 5.3 Ergebnisse der simulierten Fahr- und Antriebsdynamik bei Wicklungsumschaltung 5.4 Versuchsaufbau und Messtechnik 5.5 Untersuchungsergebnisse von Generator mit Dieselmotor 5.6 Untersuchungsergebnisse des Radantriebes 5.7 Ergebnisse der gemessenen Fahr- und Antriebsdynamik bei Wicklungsumschaltung 5.8 Bewertung des Einzelradantriebssystems 6 Zusammenfassung 7 Ausblick info:eu-repo/classification/ddc/620 ddc:620
17	Sensor fusion and fault diagnosticsin non-linear dynamical systems. Nilsson, Albin January 2020 (has links) Sensors are highly essential components in most modern control systems and are used in increasingly complex ways to improve system precision and reliability. Since they are generally susceptible to faults it is common to perform on-line fault diagnostics on sensor data to verify nominal behavior. This is especially important for safety critical systems where it can be imperative to identify, and react to, a fault before it increases in severity. An example of such a safety critical system is the propulsion control of a vehicle. In this thesis, three different model-based methods for Fault Detection and Isolation (FDI) are developed and tested with the aim of detecting and isolating sensor faults in the powertrain of an electric, center articulated, four-wheel-drive vehicle. First, kinematic models are derived that combine sensor data from all sensors related to propulsion. Second, the kinematic models are implemented in system observers to produce fault sensitive zero-mean residuals. Finally, fault isolation algorithms are derived, which detect and indicate different types of faults via evaluation of the observer residuals. The results show that all FDI methods can detect and isolate stochastic faults with high certainty, but that offset-type faults are hard to distinguish from modeling errors and are therefore easily attenuated by the system observers. Faults in accelerometer sensors need extra measures to be detectable, owing to the environment where the vehicle is typically operated. A nonlinear system model shows good conformity to the vehicle system, lending confidence to its further use as a driver for propulsion control. Fault detection and isolation FDI sensor fusion nonlinear four wheel drive vehicle kinematics kalman filter KF EKF parity relations Other Mathematics Annan matematik Information Systems
18	Konstrukční návrh pohonu přední hnané nápravy traktoru / Design of the Tractor's front axle drive Podhora, David January 2018 (has links) This master’s thesis is deal with the design of the tractor’s front axle drive to enlarge its braking efficiency of the standing tractor fixed by the parking brake. In the first two chapters, the basic information related to the above stated issue is being summarized. Next, procedure of creating the design including the fundamental calculation proposal is being described. In the last chapter, the strain-stress analysis of the selected partial sections of the design is being presented. The final design is supported with the drawing documentation that is being part of this master’s thesis, too.
19	A fundamental approximation in MATLAB of the efficiency of an automotive differential in transmitting rotational kinetic energy Vaughn, James Roy 30 July 2012 (has links) The VCOST budgeting tool uses a drive cycle simulator to improve fuel economy predictions for vehicle fleets. This drive cycle simulator needs to predict the efficiency of various components of the vehicle's powertrain including any differentials. Existing differential efficiency models either lack accuracy over the operating conditions considered or require too great an investment. A fundamental model for differential efficiency is a cost-effective solution for predicting the odd behaviors unique to a differential. The differential efficiency model itself combines the torque balance equation and the Navier-Stokes equations with models for gear pair, bearing, and seal efficiencies under a set of appropriate assumptions. Comparison of the model with existing data has shown that observable trends in differential efficiency are reproducible in some cases to within 10% of the accepted efficiency value over a range of torques and speeds that represents the operating conditions of the differential. Though the model is generally an improvement over existing curve fits, the potential exists for further improvement to the accuracy of the model. When the model performs correctly, it represents an immense savings over collecting data with comparable accuracy. / text Differential Automotive Automobile Final drive Gear Windage Bearing Seal VCOST Fuel economy Efficiency Powertrain Drivetrain Power train Drive train Model MATLAB Light-duty Heavy-duty Dual differential Tandem axle Tag axle Lubricant ATF Automatic transmission fluid Society of Automotive Engineers Walther Sutherland Wheel drive Transaxle Thermal/fluid sciences TFS TxDOT Texas Department of Transportation
20	Minimization of Noise and Vibration Related to Driveline Imbalance using Robust Design Processes Al-Shubailat, Omar 17 August 2013 (has links) Variation in vehicle noise, vibration and harshness (NVH) response can be caused by variability in design (e.g. tolerance), material, manufacturing, or other sources of variation. Such variation in the vehicle response causes a higher percentage of produced vehicles to have higher levels (out of specifications) of NVH leading to higher number of warranty claims and loss of customer satisfaction, which are proven costly. Measures must be taken to ensure less warranty claims and higher levels of customer satisfactions. As a result, original equipment manufacturers (OEMs) have implemented design for variation in the design process to secure an acceptable (or within specification) response. The focus here will be on aspects of design variations that should be considered in the design process of drivelines. Variations due to imbalance in rotating components can be unavoidable or costly to control. Some of the major components in the vehicle that are known to have imbalance and traditionally cause NVH issues and concerns include the crankshaft, the drivetrain components (transmission, driveline, half shafts, etc.), and wheels. The purpose is to assess NVH as a result of driveline imbalance variations and develop a tool to help design a more robust system to such variations. program. Java quality engineering quality capability studies manufacturing processes manufacturing engineer design engineer sales profit customer concern warranty objectionable Eigen functions vectors Eigen Eigen values identity Euler differential equations differential transfer case shaft driveline static imbalance dynamic imbalance passenger customer driver inboard ear driver outboard ear steering wheel seat track variation Gamma distribution normal distribution standard deviation average variance mean phasor victor scalar linear system LTI linear time invariant transfer function output input microphone accelerometers tachometer channels order frequency frequency domain time domain convolution Transformation Fourier Transformer Fourier imaginary and real logarithmic decibel sensitivity curves run down run up two wheel drive Four Wheel Drive Nissan Truck OEM Original Equipment Manufacturers Data Acquisitions Channels Simulation Six Sigma variability Design Robust sensitivity Vibration Imbalance Noise Harshness NVH Driveline

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