Comparison of Linear and Nonlinear MPC on Operator-In-the-Loop Overhead Cranes

Model Predictive Control has been proved to enhance the control performance of overhead cranes. However, in Operator-In-the-Loop (OIL) overhead cranes the trajectory of the payload strongly depends on the runtime decisions of the user and can not be predicted beforehand. Simple assumptions on the future references evolution have therefore to be made. In this paper we investigate the applicability of linear and nonlinear MPC strategies to the case of OIL overhead cranes, based on different assumptions on the future evolution of the length of the hoisting cable

State Variable Feedback Control Of A Gantry Crane

The outcome of this project is to design a controller to meet the requirement of high positioning accuracy and small swing angle, motion and stabilization control of gantry crane. The dynamic of the gantry crane system has been modeled in state variable form to obtain state feedback gain matrix and system parameters has been defined and suitable desired poles has been specified to complete the dynamic modeling. The State Variable Feedback Control is chosen to be implemented in gantry crane control system because it can control multiple variables which are the gantry’s position, speed, load angle and angular velocity at the same time. Block diagram constructed using Simulink which represents the controller has successfully achieved the objectives. An analytical analysis is conducted to study on the effect of system parameter changes. The scopes of studies involved will be on various types of gantry crane model, various control technique, gantry crane system modeling and simulation using MATLAB Simuli

Systems control theory applied to natural and synthetic musical sounds

Systems control theory is a far developped field which helps to study stability, estimation and control of dynamical systems. The physical behaviour of musical instruments, once described by dynamical systems, can then be controlled and numerically simulated for many purposes. The aim of this paper is twofold: first, to provide the theoretical background on linear system theory, both in continuous and discrete time, mainly in the case of a finite number of degrees of freedom ; second, to give illustrative examples on wind instruments, such as the vocal tract represented as a waveguide, and a sliding flute

State Variable Feedbaek Control of a Gantry Crane

The outcome of this project is to design a controller to meet the requirement of high positioning accuracy and small swing angle, motion and stabilization control of gantry crane. The dynamic of the gantry crane system has been modeled in state variable form to obtain state feedback gain matrix and system parameters has been defined and suitable desired poles has been specified to complete the dynamic modeling. The State Variable Feedback Control is chosen to be implemented in gantry crane control system because it can control multiple variables which are the gantry's position, speed, load angle and angular velocity at the same time. Block diagram constructed using Simulink which represents the controller has successfully achieved the objectives. An analytical analysis is conducted to study on the effect of system parameter changes. The scopes of studies involved will be on various types of gantry crane model, various control technique, gantry crane system modeling and simulation using MATLAB Simulin

Cable-Based Robotic Crane (CBRC): Design and Implementation of Overhead Traveling Cranes Based on Variable Radius Drums

In this paper, we present a new family of overhead traveling cranes based on variable radius drums (VRDs), called cable-based robotic cranes (CBRCs). A VRD is characterized by the variation of the spool radius along its profile. This kind of device is used, in this context, for the development of a cable-robot, which can support and move a load through a planar working area with just two degrees of freedom. First we present the kinematic analysis and the synthesis of the geometry of a VRD profile. Then, the schema of a bidimensional horizontal moving mechanism, based on the VRD theory, and an experimental prototype of a three-dimensional CBRC are presented. The features of this wire-based overhead crane and an analysis of cables tensions are discussed. Finally, the performance of this mechanism is evaluated, demonstrating a deviation between the end-effector and the nominal planar surface of less than 1% throughout the whole working area

Dynamics and Embedded Internet of Things Input Shaping Control for Overhead Cranes Transporting Multibody Payloads

Input shaping is an Optimal Control feedforward strategy whose ability to define how and when a flexible dynamical system defined by Ordinary Differential Equations (ODEs) and computer controlled would move into its operative space, without command induced unwanted dynamics, has been exhaustively demonstrated. This work examines the issue of Embedded Internet of Things (IoT) Input Shaping with regard to real time control of multibody oscillatory systems whose dynamics are better described by differential algebraic equations (DAEs). An overhead crane hanging a double link multibody payload has been appointed as a benchmark case; it is a multibody, multimode system. This might be worst scenario to implement Input Shaping. The reasons can be found in the wide array of constraints that arise. Firstly, the reliability of the multibody model was tested on a Functional Mock-Up Interface (FMI) with the two link payload suspended from the trolley by comparing the experimental video tapping signals in time domain faced with the signals extracted from the multibody model. The FFTs of the simulated and the experimental signal contain the same frequency harmonics only with somewhat different power due to the real world light damping in the joints. The application of this approach may be extended to other cases i.e., the usefulness of mobile hydraulic cranes is limited because the payload is supported by an overhead cable under tension that allows oscillation to occur during crane motion. If the payload size is not negligible small when compared with the cable length may introduce an additional oscillatory mode that creates a multibody double pendulum. To give the insight into the double pendulum dynamics by Lagrangian methods two slender rods as payloads are analyzed dealing with the overhead crane and a composite revolute-revolute joint is proposed to model the cable of the hydraulic crane, both assumptions facilitates an affordable analysis.This research was funded by Ministerio de Ciencia e Innovación and FEDER Funds. Research project MAQ-STATUS-2016

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

Dynamic analyses of gantry crane under several trolley and payload movements

Izučava se dinamičko ponašanje realne portalne dizalice izložene većem broju pokreta kolica i korisnog tereta. Razvijen je poseban numerički postupak koji je primenjen metodom konačnih elemenata na simulaciju različitih načina kretanja glavne grede. Rezultati jasno pokazuju da pomeraj krana, naročito longitudinalni, u velikoj meri zavisi od ubrzanja kako u početnoj tako i u fazi zaustavljanja, čemu su kolica izložena za vreme kretanja glavne grede krana. Poslednji deo rada prikazuje simulaciju iznenadnog zaustavljanja kretanja kolica i potonjeg ljuljanja korisnog tereta; u ovom slučaju, dužina užeta koje zaustavlja koristan teret na kolicima ima glavnu ulogu u određivanju kretanja i maksimalnog longitudinalnog pomeraja dizalice.The aim of this research is to study the dynamic behaviour of a real gantry crane subjected to the actions induced by the trolley and payload movement. A specific numerical procedure was developed and implemented in the finite element method in order to simulate different trolley movement modes on the crane's main beam. From the results, it is clear that the crane displacement, especially the longitudinal one, is strongly dependent on the acceleration both in the starting phase and in the stopping phase to which the trolley is subjected during its movement on the crane main beam. The last part of this research simulates the sudden stop of the trolley movement and subsequent payload swinging; in this case, the length of the rope that suspend the payload to the trolley has a fundamental role in the trend and maximum longitudinal crane displacement value