Trolley motion control based on S-shaped velocity profile for quay crane cargo oscillation comparison

Quay cranes are used to move containers from ship to store in minimum time so that the load reaches its destination without payload oscillation. During the operations, containers are suspended by cables and it’s free to swing by motion. This paper investigates the two different velocity profiling techniques used for quay crane control and cargo stabilization. A laboratory scaled model of a crane is used to experimentally research, where the trolley acceleration is used as input, for suppressing the container sway. The residual cargo oscillation problems using different velocity profiles are discussed. Article in English. Krantinės krano vežimėlio judėjimo valdymas taikant S formos greičio profilį siekiant palyginti krantinės krano krovinio svyravimus Santrauka Krantinės kranai yra naudojami konteineriams transportuoti iš laivo į krantą siekiant užtikrinti minimalų krovos laiką taip, kad krovinys pasiektų savo tikslą esant minimaliems svyravimas. Atliekant tokius krovos darbus krantinės kranu konteineris kabo ant lynų, todėl dėl transportavimo judesių gali atsirasti svyravimų. Šiame darbe analizuojami du skirtingi greičio profiliai, naudojami krantinės krano vežimėlio judesiui valdyti ir kroviniui stabili­zuoti. Eksperimentiniams tyrimams buvo panaudotas mažesnio mastelio laboratorinis krantinės krano modelis, kuriame valdomas vežimėlio pagreitis naudojamas konteinerio svyravimams slopinti. Darbe analizuojama išliekamųjų svyravimų problema ir skirtingų greičio valdymo profilių įtaka šiems svyravimams. Reikšminiai žodžiai: konteinerinis kranas, krovimo procesas, konteinerio svyravimai, eksperimentinė analizė, valdymo sistemos, greičio profiliavimas, trapecinis profilis, S formos profilis

Detection of physical impacts of shipping containers during handling operations using the impact detection methodology

The transportation of cargo inside shipping containers is a risky operation that requires constant monitoring activities and real-time operational actions. Yet, the detection of the real dynamics of the container and the surrounding infrastructure and extraction of true subsequent critical events is still an unresolved issue among engineers. In this paper, we analyze the new physical impact detection method, namely the Impact Detection Methodology (IDM), to detect the most obvious and force-dependent impacts from acceleration data, using the IoT sensor in an experimental environment using the heavy machinery of a seaport. By variating the threshold level, we have observed the changes in the number of impacts detected within three separate case studies. Results suggest that the optimal parameters tend to provide an adequate number of events, yet even the slightest change in the threshold level can increase or decrease the number of detected impacts in a non-linear fashion, making the detection harder, due to unforeseen external impacts on the dataset, the filtering of which is still the main priority of our future research.Web of Science109art. no. 125

Uosto autonominių krovos procesų duomenų sinchronizavimo metodas

To increase the efficiency of the container handling process, one of the most promising solutions is to develop efficient data synchronization methodologies using real-time data of the quay crane and container trucks, using the support of various ICT tools/technologies. Existing planning systems do not evaluate real-time data synchronization received from all sensory units scattered across the container terminal, which leads to downtimes, increases the duration of the total handling process and increases the energy costs required to transport the cargo across the terminal to the stack. A new process data synchronization method is proposed in this work, which include a new method of wireless data collection and transmission based on LoRaWAN technology. The proposed solution includes physical prototypes of the network equipment and a developed two-layer security mechanism in LoRaWAN protocol. A new algorithm of container lowering time estimation according to a trajectory template and a new mathematical model and algorithm evaluating fuel consumption of a container truck from real movement data was developed and implemented in the proposed method. A field experiment performed in Klaipeda port shows that a one LoRaWAN station covers a medium-sized container terminal and provides reliable transmission of handling process contextual data. Computational results suggest that it is possible to diminish the AGV waiting times and thus minimize the total container handling process duration, resulting an improvement over the current method

Method of data synchronization of autonomous port handling processes

To increase the efficiency of the container handling process, one of the most promising solutions is to develop efficient data synchronization methodologies using real-time data of the quay crane and container trucks, using the support of various ICT tools/technologies. Existing planning systems do not evaluate real-time data synchronization received from all sensory units scattered across the container terminal, which leads to downtimes, increases the duration of the total handling process and increases the energy costs required to transport the cargo across the terminal to the stack. A new process data synchronization method is proposed in this work, which include a new method of wireless data collection and transmission based on LoRaWAN technology. The proposed solution includes physical prototypes of the network equipment and a developed two-layer security mechanism in LoRaWAN protocol. A new algorithm of container lowering time estimation according to a trajectory template and a new mathematical model and algorithm evaluating fuel consumption of a container truck from real movement data was developed and implemented in the proposed method. A field experiment performed in Klaipeda port shows that a one LoRaWAN station covers a medium-sized container terminal and provides reliable transmission of handling process contextual data. Computational results suggest that it is possible to diminish the AGV waiting times and thus minimize the total container handling process duration, resulting an improvement over the current method

Modeling and simulation of quay crane control system for PID controller optimal parameters determination / Krantinės krano valdymo sistemos kompiuterinis modeliavimas optimalioms PID valdiklio vertėms nustatyti

The main control object of Quay crane, which is operating in seaport intermodal terminal cargo loading and unloading process, is the crane trolley. One of the main frequent problem, which occurs, is the swinging of the container. This swinging is caused not only by external forces but also by the movement of the trolley. The research results of recent years produced various types of control algorithms by the other researchers. The control algorithms are solving separate control problems of Quay crane in laboratory environment. However, there is still complex control algorithm design and the controller’s parameter estimation problems to be solved. This paper presents mathematical model of the Quay crane trolley mechanism with the suspended cargo. The mathematical model is implemented in Matlab Simulink environment and using Dormand-Prince solving method. The presented model of laboratory quay crane mathematical model is dedicated to parameter estimation of PID controller of closed loop system with the usage of S –form speed input profile. The article includes the dynamic model of the presented system, the description of closed loop system and modeling results. These results will be used as an initial information for the PID parameters estimation in real quay crane control system. The simu-lation of the model was performed using estimated values of controller. The sway influence of the cargo, the usage of the trolley speed input S-shaper and the PID controller was used to control the trolley speed. Santrauka  Jūriniame įvairiarūšiame terminale atliekant konteinerių krovos procesus, vienas iš krantinės kranų valdymo objektų yra vežimėlis. Viena iš problemų, su kuria susiduriama dažniausiai, yra konteinerio svyravimai, kuriuos, be išorinių veiksnių, taip pat sukelia ir vežimėlio judėji-mas. Remdamiesi paskutinių kelerių metų tyrimais, mokslininkai sukūrė įvairių valdymo algoritmų, kurie laboratorinėmis sąlygomis spren-džia atskiras krantinės kranų valdymo problemas. Tačiau kompleksinių ir efektyvių valdymo algoritmų ir jų valdymo sistemos parametrų nustatymo metodai vis dar kuriami ir tobulinami. Šiame darbe sudarytas krantinės krano vežimėlio su kabančiu kroviniu mechanizmo sis-temos matematinis modelis. Šis modelis realizuotas Matlab Simulink aplinkoje ir sprendžiamas taikant Dormand-Prince metodą. Sukurtas laboratorinio krantinės krano valdymo sistemos kompiuterinis modelis skirtas uždarosios valdymo sistemos PID valdiklio parametrams nustatyti, kai užduoties signalui taikomas S formos greičio kitimo profilis. Darbe pateiktas sistemos dinaminis modelis, aprašyta uždaroji valdymo sistema, pateikti kompiuterinio modeliavimo rezultatai, kuriuos planuojama panaudoti kaip pradinę informaciją realaus krano PID valdiklio parametrams derinti. Atlikta simuliacija naudojant nustatytas vertes ir įvertinti krovinio svyravimai taikant S formos greičio kitimo profilį kartu su PID valdikliu vežimėlio greičiui valdyti. Reikšminiai žodžiai: krantinės kranas, matematinis modelis, valdymo sistema, S profilis, PID valdiklis, Matlab

Multibody dynamic simulation and transient analysis of quay crane spreader and lifting mechanism

Nowadays, container shipment in the intermodal terminals is overloaded. The quay crane and its control system have to be properly prepared for rapid cargo reloading. The advanced control system may increase container loading efficiency due to the reduced transportation time. However, faster transportation demands higher safety. In this article, the authors performed multibody dynamics simulation of the container spreader and lifting mechanism by analyzing more advanced mathematical model of the quay crane. Trolley motion and cargo swing angle transient responses of the dynamic system were acquired and analyzed during model simulation. The main target of this research is to determine the system behavior during transients. The simulation results showed that the transients induced by startup of the vertical spreader travel affect the whole crane system in all the investigated cases. In addition, the influence of flexible cable causes additional oscillations of cargo and reciprocating trolley displacement. The simulation of the container spreader and lifting mechanism will help detect motion deviations of the quay crane in real time

Development of an adaptive intermodal container handling control subsystem based on automatic recognition algorithms

One of most important research area of our paper is development of adaptive container loading system w ith computer vision algorithms for smooth container lan ding on the platform (truck, trailer or well car of the train), whereas excessive vibration is caused at th at moment, this vibration and shocks can cause cont ainer and/or cargo damage. This paper presents container crane grabber adaptive positioning subsystem that uses computer vision algorithms. Designed subsystem consists of two separate parts: an automatic image recognition system and the adaptive control system, which is based on neural network with fuzzy interf ace. This network is using learning algorithms so it can easily control container crane motors and adapt to changing conditions (container weight, platform hei ght). Functional computer vision algorithms is prop osed and based on them computer programs was developed. Electric circuits is also created and described, th at allows testing and validation of this subsystem

Use case of quay crane container handling operations monitoring using ICT to detect abnormalities in operator actions

This paper presents the initial research findings from the Klaipeda port monitoring action related to Blue economy development initiative in the Baltic Sea. Use case study demonstrates the possibility to address the problem of information system deployment in harsh industrial environment to gather valuable statistical knowledge. Custom made monitoring and data transmission units were developed to utilize the best practice of engineering to solve real problems of Klaipeda Port. Several key operations and parameters were monitored during the research, including containers spreader movements, physical characteristics of the cables, metal constructions. Initial results suggested that crane operators’ involvement in the control of the cargo movement produced incorrect control patterns (joystick movements) that delayed port operations. Each control movement of the joystick needs to have a direct real-time feedback from the spreader (actual movement of the cargo). Feedback control functiona lity will allow adjusting the spreader movement according to the operator and will decrease the cargo transportation time during constant breaks

Analysis of the efficiency of shipping containers handling/loading control methods and procedures

Most modern quay cranes operate under the operator’s control. Lifting, lowering, and transporting a container from one platform to another are just some of the actions that a person is responsible for, but the negative consequences of handling can be caused not only by his actions. An error, loading transient instability, or an undervalued environmental factor in the control algorithm can cause a risk to human safety, container, and cargo security. In order to control cargohandling risk, it is necessary to improve the cargo control systems not only by changing their software, but also by creating additional control algorithms and systems. These systems with programmed control algorithms should be integrated into existing systems to control cargo security and its transfer time. In this article, transient processes and dynamic property of the cargo-handling operation are described and multibody dynamics simulation performed using laboratory prototype of a quay crane. The experimental research performed and integrated autonomous quay crane control algorithm developed with the proposed embedded container swinging control subroutine operated in optimal mode when the control system used PID controller with a feedback including additional PI controller and S-shaped input signal for the analyzed case with the defined parameter set

Statistical Evaluation of the Impacts Detection Methodology (IDM) to Detect Critical Damage Occurrences during Quay Cranes Handling Operations

During various marine container handling operations, performed mainly in larger-scale container terminals, containers get damaged regularly. Our previous studies showed that each physical impact results in some form of physical deformation of the backbone structure. Even at low accelerations, the spreaders of the quay cranes impact the containers with enough force to substantially bend the metal parts of the corners of the containers, when additional hooking procedures are required. This means that the first time resulted in the metal rods hitting the metal frame with an average 15-ton mass at the average speed of 1.7 m/s. The metal rods of the hooking mechanisms’ impact areas of the containers are structurally important, and each impact surely damages the containers, diminishing their total operational time. We have already proposed the Impacts Detection Methodology (IDM) and its application system, tested in Klaipeda City port, and it proved to be efficient in real-time operations, detecting concurrent impacts with each new handling cycle. In this paper, we provide a summarisation of a larger number of detections using the IDM, and as a result of this analysis, we have detected that more impact events happen when containers are taken from the upper parts of the ship, in comparison to the ones taken from the shafts. Results suggest that more critical events occur due to operator actions and experiences working with the machinery, yet the same operators tend to make fewer impact mistakes taking the containers from the shafts as the vertical cell guides tend to direct the movements and lower the levels of the natural sway of the spreader inside closed environments. This surely damages the metal infrastructure of the shafts, as seen in our previous study, but minimizes the chances of secondary impacts occurring during hooking