Automation of ship-to-shore container cranes: A review of state-of-the-art

U radu je prikazan pregled dostignutog stepena razvoja i istraživanja u oblasti automatizacije obalskih kontejnerskih dizalica. Primenom različitih tehnika automatizacije povećava se produktivnost obalskih kontejnerskih dizalica, a sledstveno tome se povećava i efikasnost lučkih terminala kao integralnog dela logističke mreže. U radu je, takođe, prikazan pregled nekih najznačajnijih publikovanih istraživanja iz oblasti upravljanja kod kontejnerskih dizalica, a dati su i principi rada trenutno postojećih uređaja za umirivanje oscilovanja tereta - kontejnera.The paper gives the state-of-the-art of automation of ship-to-shore (STS) container cranes, as the biggest investments in the port terminal system. The automation techniques increase the productivity of the ship-to-shore container crane, and consequently increase the port terminal efficiency, as an integral part of logistic network. The paper also shows a short survey of some most important and recent researches in control of ship-to-shore cranes, and main principles of operation of antis way currently existing devices

Automation of ship-to-shore container cranes: A review of state-of-the-art

U radu je prikazan pregled dostignutog stepena razvoja i istraživanja u oblasti automatizacije obalskih kontejnerskih dizalica. Primenom različitih tehnika automatizacije povećava se produktivnost obalskih kontejnerskih dizalica, a sledstveno tome se povećava i efikasnost lučkih terminala kao integralnog dela logističke mreže. U radu je, takođe, prikazan pregled nekih najznačajnijih publikovanih istraživanja iz oblasti upravljanja kod kontejnerskih dizalica, a dati su i principi rada trenutno postojećih uređaja za umirivanje oscilovanja tereta - kontejnera.The paper gives the state-of-the-art of automation of ship-to-shore (STS) container cranes, as the biggest investments in the port terminal system. The automation techniques increase the productivity of the ship-to-shore container crane, and consequently increase the port terminal efficiency, as an integral part of logistic network. The paper also shows a short survey of some most important and recent researches in control of ship-to-shore cranes, and main principles of operation of antis way currently existing devices

Input shaping-based control schemes for a three dimensional gantry crane

The motion induced sway of oscillatory systems such as gantry cranes may decrease the efficiency of production lines. In this thesis, modelling and development of input shaping-based control schemes for a three dimensional (3D) lab-scaled gantry crane are proposed. Several input shaping schemes are investigated in open and closed-loop systems. The controller performances are investigated in terms of trolley position and sway responses of the 3D crane. Firstly, a new distributed Delay Zero Vibration (DZV) shaper is implemented and compared with Zero Vibration (ZV) shaper and Zero Vibration Derivative (ZVD) shaper. Simulation and experimental results show that all the shapers are able to reduce payload sway significantly while maintaining desired position response specifications. Robustness tests with ±20% error in natural frequency show that DZV shaper exhibits asymmetric robustness behaviour as compared to ZV and ZVD shapers. Secondly, as analytical technique could only provide good performance for linear systems, meta-heuristic based input shaper is proposed to reduce sway of a gantry crane which is a nonlinear system. The results show that designing meta-heuristic-based input shapers provides 30% to 50% improvement as compared to the analytical-based shapers. Subsequently, a particle swarm optimization based optimal performance control scheme is developed in closed-loop system. Simulation and experimental results demonstrate that the controller gives zero overshoot with 60% and 20% improvements in settling time and integrated absolute error value of position response respectively, as compared to a specific designed PID-PID anti swing controller for the lab-scaled gantry crane. It is found that crane control with changing cable length is still a problem to be solved. An adaptive input shaping control scheme that can adapt to variation of cable’s length is developed. Simulation with real crane dimensions and experimental results verify that the controller provides 50% reduction in payload sway for different operational commands with hoisting as compared to the average travel length approach

Space science/space station attached payload pointing accommodation study: Technology assessment white paper

Technology assessment is performed for pointing systems that accommodate payloads of large mass and large dimensions. Related technology areas are also examined. These related areas include active thermal lines or power cables across gimbals, new materials for increased passive damping, tethered pointing, and inertially reacting pointing systems. Conclusions, issues and concerns, and recommendations regarding the status and development of large pointing systems for space applications are made based on the performed assessments

Intelligent flight control systems

The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms

Design and optimization of input shapers for liquid slosh suppression

The need for fast maneuvering and accurate positioning of flexible structures poses a control challenge. The flexibility inherent in these lightly damped systems creates large residual vibrations in response to fast disturbances. Several control approaches have been proposed to tackle this class of problems, of which the input shaping technique seems quite appealing. While input shaping has been widely investigated to attenuate residual vibrations in flexible structures, less attention was granted to expand its viability in further applications. It is therefore the aim of this work to develop a methodology for applying input shaping techniques to suppress sloshing effects in open moving containers to facilitate safe and fast point-to-point movements. The liquid behavior is modeled using finite element analysis. The input shaper parameters are optimized to find the commands that would result in minimum residual vibration. Other objectives, such as improved robustness and motion constraints such as deflection limiting are also included in the optimization scheme. Numerical results are verified on an experimental setup consisting of a small motor-driven water tank that is precisely guided to undergo rectilinear motion, while measuring both the tank motion and free surface displacement of the water. The results obtained suggest that input shaping is an effective method for suppressing residual liquid vibrations