Development of Motion Control Systems for Hydraulically Actuated Cranes with Hanging Loads

Automation has been used in industrial processes for several decades to increase efficiency and safety. Tasks that are either dull, dangerous, or dirty can often be performed by machines in a reliable manner. This may provide a reduced risk to human life, and will typically give a lower economic cost. Industrial robots are a prime example of this, and have seen extensive use in the automotive industry and manufacturing plants. While these machines have been employed in a wide variety of industries, heavy duty lifting and handling equipment such as hydraulic cranes have typically been manually operated. This provides an opportunity to investigate and develop control systems to push lifting equipment towards the same level of automation found in the aforementioned industries. The use of winches and hanging loads on cranes give a set of challenges not typically found on robots, which requires careful consideration of both the safety aspect and precision of the pendulum-like motion. Another difference from industrial robots is the type of actuation systems used. While robots use electric motors, the cranes discussed in this thesis use hydraulic cylinders. As such, the dynamics of the machines and the control system designmay differ significantly. In addition, hydraulic cranes may experience significant deflection when lifting heavy loads, arising from both structural flexibility and the compressibility of the hydraulic fluid. The work presented in this thesis focuses on motion control of hydraulically actuated cranes. Motion control is an important topic when developing automation systems, as moving from one position to another is a common requirement for automated lifting operations. A novel path controller operating in actuator space is developed, which takes advantage of the load-independent flow control valves typically found on hydraulically actuated cranes. By operating in actuator space the motion of each cylinder is inherently minimized. To counteract the pendulum-like motion of the hanging payload, a novel anti-swing controller is developed and experimentally verified. The anti-swing controller is able to suppress the motion from the hanging load to increase safety and precision. To tackle the challenges associated with the flexibility of the crane, a deflection compensator is developed and experimentally verified. The deflection compensator is able to counteract both the static deflection due to gravity and dynamic de ection due to motion. Further, the topic of adaptive feedforward control of pressure compensated cylinders has been investigated. A novel adaptive differential controller has been developed and experimentally verified, which adapts to system uncertainties in both directions of motion. Finally, the use of electro-hydrostatic actuators for motion control of cranes has been investigated using numerical time domain simulations. A novel concept is proposed and investigated using simulations.publishedVersio

Volume 3 – Conference

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 8: Pneumatics Group 9 | 11: Mobile applications Group 10: Special domains Group 12: Novel system architectures Group 13 | 15: Actuators & sensors Group 14: Safety & reliabilit

Modelling and Simulation of a Novel Liquamatic Fire Monitor A fully automated fire recognition- and suppression system based on infrared machine vision technology

Masteroppgave i mekatronikk - Universitetet i Agder, 2015Background: Fire monitors are effective fire extinguishing apparatuses which combine high accuracy with long range. As part of the mechatronic trend, research has during recent years started to delve into the automation of re monitors. This involves proper actuation and control of re monitors in order to extinguish re. Up to this point, however, research has primarily been concerned with indoor operation. The aim of the present thesis is to develop a system for an electrically actuated re monitor which detects, localizes and suppresses re in an outdoor environment without the need for manual operation. Solution & Experiments: Fire is localized with computer analysis of IR stereo camera images. Based on the position of the re, mathematical models found in literature are used to determine the optimum con guration of the monitor in order to extinguish the re. Servomotors which actuate the monitor are modelled and simulated in real time using a HIL setup. A PLC is programmed to generate control signals to the servomotors. The accuracy of the stereo vision system is tested experimentally by estimating the distance to a live re at distances between 30 and 60 m. In addition, the system's ability to distinguish a re from other hot objects is tested. Liquid jet trajectory models are obtained from relevant research papers found in open literature. Parameters from these models are determined based on experiments conducted outdoors with a re monitor where wind disturbances are measured. Results: The stereo vision system exhibited a maximum error of 0.5 m or 1.6 %. The vision system is successful in distinguishing between a wooden re, a person and a pot with boiling water. The best model to predict jet trajectories found in literature yields an average error of 1.6 m from measured data with little wind present, and 9.8 m mean deviation with comparatively strong wind disturbances. Simulations are carried out with only minor discrepancies with one of the models implemented on the PLC. Conclusion: Computer algorithms which localize re in conjunction with IR cameras has been designed. The limiting factor with regards to the system's accuracy is precise predictions of the water jet's travel. The accuracy of the trajectory models as compared to experimental data measured under presented circumstances are of limited use. In addition, there are marginal di erences between the presented trajectory models found in literature, and therefore either one may be used. A PLC program has been created. HIL simulations are carried out with only minor discrepancies as compared to the predicted trajectories from one of the models

Tagungsband Mechatronik 2011: Dresden 31. März – 1. April 2011

Mit dieser sechsten Auflage der Tagung MECHATRONIK 2011 verbindet sich neben dem 10-jährigen Tagungsjubiläum (die erste Tagung fand im Jahre 2001 statt) auch gleichzeitig eine Premiere. Nachdem die ersten fünf Tagungen erfolgreich unter den Fittichen des VDI bzw. des VDI-Wissensforums stattgefunden hatten, beginnt das zweite MECHATRONIK-Dezennium in einem geänderten Format und mit neuen Verantwortlichkeiten und wird dennoch die bewährten Traditionen der deutschsprachigen Mechatronik-Fachgemeinde weiter pflegen. Academia trifft Industrie — Mechatronik und mechatronische Produkte sind seit jeher geprägt durch die Verknüpfung von interdisziplinärem methodenorientierten Wissen und nutzerorientierter Produktgestaltung. Diese Verknüpfung bildet sich höchst erfolgreich speziell in der deutschsprachigen Mechatronik-Fachgemeinde ab, nicht zuletzt deshalb haben deutsche Mechatronikprodukte weltweit eine exzellente Marktpräsenz. Diese enge Verzahnung ist aber ebenso im Tagungsgeschehen etabliert, wo seit vielen Jahren, im Gegensatz zu vielen anderen Ländern und internationalen Tagungen, eine gute Balance zwischen Teilnehmern aus Hochschulen und Industrie gegeben ist. Dies trifft auch auf die MECHATRONIK 2011 zu, mit 47 (70 %) Beiträgen aus Hochschulen und 20 (30 %) Beiträgen aus der Industrie bzw. Industriebeteiligung. Academia trifft Industrie — Dieser Sachverhalt wird zukünftig auch ganz transparent an den Tagungsorten und dem Tagungsumfeld sichtbar sein. Ab diesem Jahr 2011 wird die Organisation und Ausrichtung durch akademische Tagungsveranstalter durchgeführt werden. Die bisherigen wissenschaftlichen Tagungsleiter Prof. Burkhard Corves (Rheinisch- Westfälische Technische Hochschule - RWTH Aachen) und Prof. Klaus Janschek (Technische Universität Dresden) werden zukünftig gemeinsam mit Prof. Torsten Bertram (Technische Universität Dortmund) für die Ausrichtung und Durchführung verantwortlich zeichnen. Als Veranstaltungsort sind entsprechende Räumlichkeiten an den beteiligten Universitäten geplant (2011 in Dresden, 2013 in Aachen, 2015 in Dortmund). Neben einer Kostenersparnis erwarten sich die Veranstalter durch das gegenüber Kongresszentren doch intimere Umfeld einen lebendigen Gedankenaustausch zwischen Wissenschaftlern, Industrievertretern und nicht zuletzt mit dem wissenschaftlichen Nachwuchs. Speziell Studierenden soll damit ein einfacherer Zugang in die Welt des wissenschaftlichen Diskurses mit Experten aus der Industrie und Praxis ermöglicht werden. Academia trifft Industrie — Eine Stärke der bisherigen MECHATRONIK-Tagungen war immer die breite fachliche Verankerung durch die verantwortliche Trägerschaft der VDI-Gesellschaft Produkt- und Prozessgestaltung (VDI-GPP) und VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (VDI/VDEGMA). Im Selbstverständnis dieser Fachgesellschaften spielt die Bereitstellung von Kommunikationsplattformen zwischen Hochschulen und Industrie eine zentrale Rolle. In den verschiedenen Fachausschüssen von VDI-GPP und VDI/VDE-GMA findet dieser Meinungs- und Informationsaustausch regelmäßig statt. Um eine breitere Fachöffentlichkeit in diese Diskussionen einzubeziehen, ist eine gemeinsame Tagung zum Thema Mechatronik eine logische und fruchtbare Konsequenz. Auch zukünftig wird der enge fachliche und institutionelle Kontakt der Tagung MECAHTRONIK zu den Fachgesellschaften aufgrund der personellen Verankerung der Tagungsveranstalter in den Fachgesellschaften VDI-GPP und VDI/VDE-GMA erhalten bleiben. Das Tagungsprogramm 2011 bietet ein breit gefächertes Angebot an aktuellen und innovativen Fragestellungen zur Mechatronik: mechatronische Produkte, Serienfertigung mechatronischer Produkte, Ressourceneffizienz, Nutzerfreundlichkeit und Akzeptanz, Entwicklungsmethoden und -werkzeuge sowie innovative Konzepte

Modelling, Simulation and Control of offshore crane Develop a kinematic and dynamic crane model and study of several control designs

Master's thesis Mechatronics MAS500 - University of Agder 2018This master thesis is about Modelling, Simulation and Control of a MacGregor Active Heave Compensation (AHC) 250t crane operating on the supply vessel Gran Canyon. The crane model was developed mathematically using robot modeling theory including both kinematic and dynamic equations. This model was developed and simulated in Matlab and Simulink and further compared, where the two models showed equal results. Control designs for an offshore crane can be developed in several ways, but in this thesis the control task only concerns position control of the crane and can be divided into two control tasks. The main goal is to determine the most suitable controller design for the two control tasks, which are as follows: • Control of crane joints with the aim to get the joint angles to follow a desired joint angle, which is a sine wave with an amplitude of one, with as small error between desired and measured join angles as possible. • Control of crane end-effector in vertical direction with the aim to get the end-effector position in z-direction to follow a desired end-effector position in z-direction with as small error between desired and measured position as possible. The desired position is a linear movement from 5.432m to 1m with a velocity of 0.1m/s. Then the end-effector should be kept steady at 1m. The dynamic model of the crane was implemented in Simulink and various control designs were developed with the task of controlling the joint angles and the end-effector position in vertical direction, using the dynamic model as the plant. PID-, PI and PD-controller design and Linear-Quadratic Regulator (LQR) design were developed to perform control of joint angles and end-effector separately. Two inverse kinematics methods were developed with the aim of controlling the end-effector based on the kinematic equations. Using the inverse Jacobian for this purpose caused singularities, but using the transpose Jacobian instead made it possible to simulate the system. Simulations showed that a PID-controller design had the best performance when controlling the joint angles, with a maximal error between desired joint angle and measure joint angle of q1error = 2.775 10−3[rad], q2error = 3.327 10−3[rad] and q3error = 6.268 10−4[rad]. While a PD-controller design showed the best performance when controlling the end-effector position in vertical direction, with a maximal error between desired and measured position as zeerror = 2.826[mm]

Recent Advances in Multi Robot Systems

To design a team of robots which is able to perform given tasks is a great concern of many members of robotics community. There are many problems left to be solved in order to have the fully functional robot team. Robotics community is trying hard to solve such problems (navigation, task allocation, communication, adaptation, control, ...). This book represents the contributions of the top researchers in this field and will serve as a valuable tool for professionals in this interdisciplinary field. It is focused on the challenging issues of team architectures, vehicle learning and adaptation, heterogeneous group control and cooperation, task selection, dynamic autonomy, mixed initiative, and human and robot team interaction. The book consists of 16 chapters introducing both basic research and advanced developments. Topics covered include kinematics, dynamic analysis, accuracy, optimization design, modelling, simulation and control of multi robot systems

Motion Control of Hydraulic Winch Using Variable Displacement Motors

The paper II is excluded from the dissertation with respect to copyright.To compete in the open market of the offshore crane industry, it is imperative for the manufacturer to continuously improve crane operability. In this context, the crane operability is expressed by means of a so-called weather window. The weather window is computed from the crane characteristics in combination with that of the vessel and the payload to be handled. It returns a set of boundaries for when it is accepted to perform a planned lift, mainly in terms of current sea-state and wind. The most important crane operability characteristics that enter into the computation of the weather window are maximum wire velocity and load capacity. This thesis focuses on how to improve the operability of active heave compensated offshore cranes. Two ways of achieving that goal have been investigated, namely, an improved control strategy and the use of model-based lift planning. The system investigated is the hydraulic active/passive winch system used by National Oilwell Varco. A new control strategy for the system was developed, tested, and implemented. The new strategy utilizes that variable displacement of the hydraulic motors of the active system of the winch drive. The strategy, semi secondary control, gave significant benefits in terms of reduced peak-pressure, increased load capacity, increased wire-speed capacity, and smoother winch performance at low winch speed. The results were validated and verified through simulations and in-field measurements.publishedVersio