135 research outputs found
Integrated sensing, dynamics and control of a moble gantry crane
This thesis investigates the dynamics and control of a Rubber Tyred Gantry (RTG)
crane which is commonly used in container handling operations. Both theoretical and
experimental work has been undertaken to ensure the balance of this research.
The concept of a Global Sensing System (GSS) is outlined, this being a closed loop
automatic sensing system capable of guiding the lifting gear (spreader) to the location
of the target container by using feedback signals from the crane's degrees of freedom.
To acquire the crucial data for the coordinates and orientation of the swinging
spreader a novel visual sensing system (VSS) is proposed. In addition algorithms used
in the VSS for seeking the central coordinates of the clustered pixels from the digitised
images are also developed.
In order to investigate the feasibility of different control strategies in practice, a scaleddown, 1/8 full size, experimental crane rig has been constructed with a new level of
functionality in that the spreader in this rig is equipped with multiple cables to emulate
the characteristics of a full-size RTG crane. A Crane Application Programming
Interface (CAPI) is proposed to reduce the complexity and difficulty in integrating the
control software and hardware. It provides a relatively user-friendly environment in
which the end-user can focus on implementing the more fundamental issues of control
strategies, rather than spending significant amounts of time in low-level devicedependent programming.
A control strategy using Feedback Linearization Control (FLC) is investigated. This
can handle significant non-linearity in the dynamics of the RTG crane. Simulation
results are provided, and so by means of the CAPI this controller is available for direct
control of the experimental crane rig. The final part of the thesis is an integration of the
analyses of the different subjects, and shows the feasibility of real-time implementation
Payload's sway angle measurement for container in the crane system based on remote sensing
The demand for a high quickly measuring angle in the port crane system should be
considered when the container has been transferred from one place to another place. It is
significant to build the feedback linking of payload's angle in the integrated crane system.
The value of accurate measurement of the angle can be used to optimize the crane control
system. In this context, the design and implementation of the experimental setup
associated with emulated cranes will be carried out. Several solutions for remote angle
measurement were considered one of the considered solutions being represented by
millimeter microwave radar sensors. Special developments of algorithms to calculate the
sway angle of payload or container were considered as so as the real-time processing
using Arduino Uno computation platform. The following objectives were successfully
reached.
1. Development of remote sensing system for payload's swing angle measurement
considering radars such the sensing devices;
2. Development of a novel angle algorithm measurement and real-time processing of
data;
3. Development of a prototype characterized by real-time processing and remote
detection capabilities considering short-range and long-range measurements, such as lidar
sensor or radar sensor.A demanda por um ângulo de medição rápido e alto no sistema de guindaste portuário
deve ser considerada quando o contêiner for transferido de um local para outro. É
significativo construir a ligação de feedback do ângulo da carga útil no sistema de
guindaste integrado. O valor da medição precisa do ângulo pode ser usado para otimizar
o sistema de controle do guindaste. Neste contexto, será realizada a concepção e
implementação da configuração experimental associada a gruas emuladas. Diversas
soluções para medição remota de ângulos foram consideradas uma das soluções
consideradas sendo representadas por sensores de micro-ondas milimetrados.
Desenvolvimentos especiais de algoritmos para calcular o ângulo de oscilação da carga
útil ou contêiner foram considerados, assim como o processamento em tempo real usando
a plataforma de computação Arduino Uno. Os seguintes objetivos foram alcançados com
sucesso.
1. Desenvolvimento de sistema de sensoriamento remoto para medição do ângulo de
oscilação da carga útil considerando radares como os dispositivos de detecção;
2. Desenvolvimento de um novo algoritmo de medição de ângulos e processamento de
dados em tempo real;
3. Desenvolvimento de um protótipo caracterizado por processamento em tempo real
e capacidade de detecção remota considerando medições de curto e longo alcance, como
sensor LIDAR ou sensor de radar
Advanced Discrete-Time Control Methods for Industrial Applications
This thesis focuses on developing advanced control methods for two industrial
systems in discrete-time aiming to enhance their performance in delivering the
control objectives as well as considering the practical aspects. The first part
addresses wind power dispatch into the electricity network using a battery
energy storage system (BESS). To manage the amount of energy sold to the
electricity market, a novel control scheme is developed based on discrete-time
model predictive control (MPC) to ensure the optimal operation of the BESS in
the presence of practical constraints. The control scheme follows a decision
policy to sell more energy at peak demand times and store it at off-peaks in
compliance with the Australian National Electricity Market rules. The
performance of the control system is assessed under different scenarios using
actual wind farm and electricity price data in simulation environment. The
second part considers the control of overhead crane systems for automatic
operation. To achieve high-speed load transportation with high-precision and
minimum load swings, a new modeling approach is developed based on independent
joint control strategy which considers actuators as the main plant. The
nonlinearities of overhead crane dynamics are treated as disturbances acting on
each actuator. The resulting model enables us to estimate the unknown
parameters of the system including coulomb friction constants. A novel load
swing control is also designed based on passivity-based control to suppress
load swings. Two discrete-time controllers are then developed based on MPC and
state feedback control to track reference trajectories along with a feedforward
control to compensate for disturbances using computed torque control and a
novel disturbance observer. The practical results on an experimental overhead
crane setup demonstrate the high performance of the designed control systems.Comment: PhD Thesis, 230 page
The Development of the New Concept of Autonomous Cranes
Předložená dizertační práce si klade za cíl ověřit možnosti použití kapacitních snímačů zrychlení na jeřábové a manipulační technice. Kapacitní snímače zrychlení typu MEMS jsou dnes hojně využívány v elektronice, např. notebooky a mobilní telefony. Použití těchto snímačů by mohlo pomoci v automatizaci jeřábů, což by ve výsledku snížilo finanční náklady na manipulaci s materiálem. Precizní znalost vlastního stavu a polohy stroje a břemene je nezbytnou součástí autonomních manipulátorů. První část práce se zabývá rešerší vědecké práce u nás v ČR a ve světě. Dále jsou popsány možnosti matematického popisu pohybu břemene na lanovém závěsu s uvedenými řešenými příklady. Jedna z kapitol se věnuje popisu snímačů, které by mohly být při automatizaci jeřábů použity. Hlavní částí práce je popis několika experimentů. Experimenty byly prováděny na laboratorním pracovišti postaveném speciálně pro tato měření. Jsou popsány především základní jednodušší modely, na kterých jsou názorně ukázány možnosti snímače. Poslední část práce se věnuje nastínění dalšího možného postupu výzkumu v této oblasti.The presented PhD thesis aims to verify the possibilities of using capacitive accelerate sensors on the crane and handling technology. Capacitive acceleration sensors of MEMS type are currently widely used in electronics, e.g. laptops and mobile phones. Using these sensors could help to automate cranes, which would eventually reduce the financial costs of material handling. Precise knowledge of their own condition and position of the machine and the load is a necessary part of autonomous manipulators. The first part of thesis deals with the exploration of scientific research in the Czech Republic and abroad. Furthermore the options of mathematical description of moving the load on the rope tow are described including solved examples. One chapter is devoted to the description of sensors that could be used in the automation of cranes. The main part is focused on description of several experiments. The experiments were conducted in a lab constructed specially for this measurement. Mainly basic simpler models are described illustrating abilities of the sensor. The last part outlines further possible progress of research in this area.
Ein neues Konzept zur Modellierung und Regelung von dynamischen Transportvorgängen in der industriellen Robotik in Echtzeit
In dieser Arbeit wird ein Konzept vorgestellt mit dem ein dynamischer Transport modelliert und geregelt werden kann. Das Vorgehen beinhaltet die Aufstellung des physikalischen Modells, Ableitung der mathematischen Beschreibung in Form von Differentialgleichungen, Modell- und physikalische Simulationen und das Experiment. Durch eine breite Auswahl von Anwendungsfällen wird die Universalität des Vorgehens veranschaulicht
Advances in Reinforcement Learning
Reinforcement Learning (RL) is a very dynamic area in terms of theory and application. This book brings together many different aspects of the current research on several fields associated to RL which has been growing rapidly, producing a wide variety of learning algorithms for different applications. Based on 24 Chapters, it covers a very broad variety of topics in RL and their application in autonomous systems. A set of chapters in this book provide a general overview of RL while other chapters focus mostly on the applications of RL paradigms: Game Theory, Multi-Agent Theory, Robotic, Networking Technologies, Vehicular Navigation, Medicine and Industrial Logistic
Underwater Vehicles
For the latest twenty to thirty years, a significant number of AUVs has been created for the solving of wide spectrum of scientific and applied tasks of ocean development and research. For the short time period the AUVs have shown the efficiency at performance of complex search and inspection works and opened a number of new important applications. Initially the information about AUVs had mainly review-advertising character but now more attention is paid to practical achievements, problems and systems technologies. AUVs are losing their prototype status and have become a fully operational, reliable and effective tool and modern multi-purpose AUVs represent the new class of underwater robotic objects with inherent tasks and practical applications, particular features of technology, systems structure and functional properties
Soft computing for tool life prediction a manufacturing application of neural - fuzzy systems
Tooling technology is recognised as an element of vital importance within the manufacturing industry. Critical tooling decisions related to tool selection, tool life management, optimal determination of cutting conditions and on-line machining process monitoring and control are based on the existence of reliable detailed process models. Among the decisive factors of process planning and control activities, tool wear and tool life considerations hold a dominant role. Yet, both off-line tool life prediction, as well as real tune tool wear identification and prediction are still issues open to research. The main reason lies with the large number of factors, influencing tool wear, some of them being of stochastic nature. The inherent variability of workpiece materials, cutting tools and machine characteristics, further increases the uncertainty about the machining optimisation problem. In machining practice, tool life prediction is based on the availability of data provided from tool manufacturers, machining data handbooks or from the shop floor. This thesis recognises the need for a data-driven, flexible and yet simple approach in predicting tool life. Model building from sample data depends on the availability of a sufficiently rich cutting data set. Flexibility requires a tool-life model with high adaptation capacity. Simplicity calls for a solution with low complexity and easily interpretable by the user. A neural-fuzzy systems approach is adopted, which meets these targets and predicts tool life for a wide range of turning operations. A literature review has been carried out, covering areas such as tool wear and tool life, neural networks, frizzy sets theory and neural-fuzzy systems integration. Various sources of tool life data have been examined. It is concluded that a combined use of simulated data from existing tool life models and real life data is the best policy to follow. The neurofuzzy tool life model developed is constructed by employing neural network-like learning algorithms. The trained model stores the learned knowledge in the form of frizzy IF-THEN rules on its structure, thus featuring desired transparency. Low model complexity is ensured by employing an algorithm which constructs a rule base of reduced size from the available data. In addition, the flexibility of the developed model is demonstrated by the ease, speed and efficiency of its adaptation on the basis of new tool life data. The development of the neurofuzzy tool life model is based on the Fuzzy Logic Toolbox (vl.0) of MATLAB (v4.2cl), a dedicated tool which facilitates design and evaluation of fuzzy logic systems. Extensive results are presented, which demonstrate the neurofuzzy model predictive performance. The model can be directly employed within a process planning system, facilitating the optimisation of turning operations. Recommendations aremade for further enhancements towards this direction
Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)
Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems
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