Three-dimensional Overhead Crane Research Articles

Research on anti-swing control strategies for three-dimensional overhead cranes with non-stationary enhanced swing angle suppression

In this paper, a non-stationary enhanced swing angle suppression control strategy is proposed to address the issue of excessive swinging angles during the transportation process of a three-dimensional overhead crane. Firstly, in response to the substantial non-stationary initial swing angle resulting from the abrupt increase in driving force during the startup of the overhead crane, we have devised a time-varying damping resistance model. This model is specifically designed to curtail the rapid force surge, subsequently diminishing the swing angle of the payload. Secondly, during the transport phase of the overhead crane, we have established an augmented coupling signal between the displacement tracking error and the payload swing angle tracking error. Drawing upon the principles of energy dissipation, we have devised a nonlinear sway controller. Next, the closed-loop stability of the control system is validated through the use of Lyapunov’s method and the LaSalle invariance principle. Finally, the proposed control strategy’s effectiveness has been substantiated through simulation analysis and physical experiments. This approach not only proves capable of effectively suppressing excessive payload swing angles during the transportation process of the overhead crane but also facilitates the rapid and precise positioning of the payload. This significantly enhances the efficiency of the overhead crane’s transport operations.

Passivity and underactuated modeling-based load energy coupling control for three-dimensional overhead crane systems

The conventional control strategies and methods with the three-dimensional model of overhead crane system are excessively dependent on model parameters and lead to the controllers design complex on position and anti-swing of overhead crane systems. With analysis on the coupling relationship among various state variables of overhead crane, the three-dimensional dynamic model of overhead crane based on mechanical virtual displacement and Lagrangian equation is constructed. A novel control strategy based on load energy coupling is designed to realize system positioning and eliminate the problem of residual load swing. The passivity of the three-dimensional overhead crane system is judged, and the energy composition of the system is deduced. The energy coupling function based on load displacement and swing angle is built. The control strategy of three-dimensional overhead crane system based on load energy coupling is designed by the Lyapunov stability theory and function construction method. The stability of the system is verified by the Lasalle invariance principle. With the experimental and programming, the proposed method is compared with different control methods. The results show that this method can realize the accurate positioning of the trolley more quickly and restrain the load swing more effectively.

Nonlinear sliding mode control of a three-dimensional double pendulum crane based on load swing state estimation: Design and experiments

In this paper, a controlled study of a three-dimensional overhead crane system with a two-stage spherical pendulum effect is carried out, and a nonlinear sliding mode control method based on load swing state estimation is proposed. The method derives the coupling relationship between the hook and the load swing angle based on the crane dynamics model and designs a linear expansion state observer (LESO) to observe the two-stage swing angle. Then, the swing angle information is fed into a controller containing a nonlinear sliding mode surface, and some rigorous mathematical proofs for the stability of this controller are presented. Finally, the theoretical analysis is experimentally verified using a prototype crane, and the results of the study show the effectiveness and strong robustness of the proposed control method.

An Online Adaptive Policy Iteration-Based Reinforcement Learning for a Class of a Nonlinear 3D Overhead Crane

We consider an online policy iteration-based reinforcement learning for a class of a nonlinear three-dimensional overhead crane with bounded uncertainties. Under the assumption that the rope length is fixed with small swing angles, a linearized model is derived. The system has four states; two actuated states: position x and y, and two un-actuated states, which are the rope angles θx and θy. The adaptive reinforcement learning controller is designed to handle the effects of measurement noises and outliers. We propose a model-free; hence it does not require precise knowledge of the system dynamics. When the state information is not available, a Kalman filter estimator is equipped with a dynamical saturation function to attenuate the effects of measurement noises and to remove outliers. A simulation study is established to illustrate the influence and robustness of the developed controller, and it can enhance the tracking trajectory under different scenarios to test the scheme.

A new regulation control method for underactuated 3D overhead cranes

Interconnection and damping assignment passivity-based control (IDA-PBC) has been successfully applied to many mechanical, electrical, and electromechanical systems. For the control of such systems, existing IDA-PBC methods have concentrated on systems with underactuation degree one, such as the ball and beam system, the vertical takeoff and landing aircraft, and the pendulum on a cart. In this paper, we focus on the application of the IDA-PBC methodology to the regulation control of a three-dimensional (3D) overhead crane system with underactuation degree two. The goal of this study is to design and analyze a regulation controller that can drive the cart to the desired position precisely and eliminate the payload swing effectively. To achieve this challenging objective, we first find an ingenious way to solve partial differential equations for constructing a Lyapunov function candidate. Then, we devise a nonlinear controller on the basis of the constructed Lyapunov function and analyze the stability of the closed-loop system by using Lyapunov techniques and LaSalle’s invariance principle. Finally, both simulation and experimental results demonstrate the proposed strategy can achieve excellent positioning accuracy and significant swing elimination, and a comparison study between the proposed method and the existing PBC method is included as well.

An Efficient Adaptive Fuzzy Hierarchical Sliding Mode Control Strategy for 6 Degrees of Freedom Overhead Crane

The paper proposes a new approach to efficiently control a three-dimensional overhead crane with 6 degrees of freedom (DoF). Most of the works proposing a control law for a gantry crane assume that it has five output variables, including three positions of the trolley, bridge, and pulley and two swing angles of the hoisting cable. In fact, the elasticity of the hoisting cable, which causes oscillation in the cable direction, is not fully incorporated into the model yet. Therefore, our work considers that six under-actuated outputs exist in a crane system. To design an efficient controller for the 6 DoF crane, it first employs the hierarchical sliding mode control approach, which not only guarantees stability but also minimizes the sway and oscillation of the overhead crane when it transports a payload to a desired location. Moreover, the unknown and uncertain parameters of the system caused by its actuator nonlinearity and external disturbances are adaptively estimated and inferred by utilizing the fuzzy inference rule mechanism, which results in efficient operations of the crane in real time. More importantly, stabilization of the crane controlled by the proposed algorithm is theoretically proved by the use of the Lyapunov function. The proposed control approach was implemented in a synthetic environment for the extensive evaluation, where the obtained results demonstrate its effectiveness.

Precision-positioning adaptive controller for swing elimination in three-dimensional overhead cranes with distributed mass beams

As a type of dispensable transport tool, overhead cranes are extensively applied in large industrial sites to transport containers and goods due to their extraordinary convenience and efficiency. However, various transport requirements and working environments may cause some adverse effects for overhead crane control. In particular, in some transport tasks, distributed-mass beams (DMB) are required to be transported smoothly to a specific position. Hence, most existing controllers designed for crane systems with point-mass payload (PMP) cannot meet the control requirements. For example, controllers designed for crane systems with PMP do not consider the moment of inertia of DMB, thus, the residual payload swing caused by the moment of inertia cannot be completely suppressed, which may cause safety risks. Additionally, due to various working environments, inaccurate estimation of frictions can result in errors in positioning. To solve the above issues, this paper conducts the dynamic analysis of three-dimensional (3-D) overhead crane systems with DMB and designs an improved adaptive controller which can provide favorable control for state variables. In particular, the proposed update laws can compensate for the uncertainties of crane systems. Based on a tracking trajectory, the trolley and guide rail can both reach the preset position, and the swing angles are also well eliminated throughout the transport process. The stability of the control system is proven theoretically, and the performance of the proposed controller is verified by comparative experiments.

Passivity-based coupling control for underactuated three-dimensional overhead cranes

This paper develops a novel Lyapunov function candidate for control of the three-dimensional (3-D) overhead crane, which yields a nonlinear controller to inject active damping. Different from the existing passivity-based controls that employ either the angular displacement or its integral as passive elements, the proposed controller incorporates both of them in a new coupled-dissipation signal, thus significantly enhancing the closed-loop passivity. Owing to the improved passivity, the proposed controller ensures the effective suppression of payload oscillations and robustness. Moreover, the control design is extended with the hyperbolic tangent function to prevent overdriving the trolley. The asymptotic stability is guaranteed by LaSalle’s invariance principle. The transit performance of the closed-loop system, including robustness, is validated by numerical simulations.

Enhanced-coupling nonlinear controller design for load swing suppression in three-dimensional overhead cranes with double-pendulum effect

To date, most control strategies have been designed for the two-dimensional and three-dimensional overhead crane systems with the single pendulum effect. In fact, three-dimensional overhead crane systems often exhibit the double-pendulum effect in practical applications, which is more controlled than the general single-pendulum crane, and also makes the controller design more challenging. This paper proposes a new nonlinear control strategy that enhances the coupling between the trolley speed and the swing angle components. Specifically, we devise a new energy-like function by introducing two generalized signals that can reflect the trolley speed and the hook and load swing angle components. This strategy greatly improves the effectiveness of the transient control process. Meanwhile, the asymptotic stability of the closed-loop system is not only guaranteed, but also the desired position of the trolley and swing angle suppression are achieved using the control strategy.

Modeling and Control of Underactuated Three-Dimensional Overhead Crane Systems

Overhead crane systems play a vital role in different factories to transport heavy loads. This paper provides an overview of recent developments in the modeling and control of three-dimensional overhead crane systems. It provides a categorized survey of the published work. Different control methodologies when applied to overhead crane are examined, outlined and assessed to aid for future work.

Real-Time Robust and Optimized Control of a 3D Overhead Crane System.

A new and advanced control system for three-dimensional (3D) overhead cranes is proposed in this study using state feedback control in discrete time to deliver high performance trajectory tracking with minimum load swings in high-speed motions. By adopting the independent joint control strategy, a new and simplified model is developed where the overhead crane actuators are used to design the controller, with all the nonlinear equations of motions being viewed as disturbances affecting each actuator. A feedforward control is then designed to tackle these disturbances via computed torque control technique. A new load swing control is designed along with a new motion planning scheme to robustly minimize load swings as well as allowing fast load transportation without violating system’s constraints through updating reference trolley accelerations. The stability and performance analysis of the proposed discrete-time control system are demonstrated and validated analytically and practically.

A novel trajectory planning-based adaptive control method for 3-D overhead cranes

ABSTRACTA three-dimensional (3-D) overhead crane is a complicated nonlinear underactuated mechanical system, for which high-speed positioning and anti-sway control are the kernel objective. Existing trajectory-based methods for 3-D overhead cranes focus on combining efficient and smooth trajectories with anti-sway tracking controllers without regard for payload motion; moreover, the exact value of plant parameters is required for accurate compensation during the control process. Motivated by these facts, we present a two-step design tracking strategy which consists of a trajectory planning stage and an adaptive tracking control design stage for 3-D overhead cranes. As shown by Lyapunov techniques and Barbalat's Lemma, the proposed controller guarantees asymptotic swing elimination and trolley positioning result in the presence of system uncertainties including unknown parameters and external disturbances. Simulation results also showed the applicability of the proposed method with good robustness against parameter uncertainties and external disturbances.

Sliding-Mode-Control-Based Robust Finite-Time Antisway Tracking Control of 3-D Overhead Cranes

In this paper, a robust finite-time antisway (i.e., antiswing and antiskew) tracking control method is developed for three-dimensional (3-D) overhead crane systems using a sliding-mode control (SMC) method. In order to control the overhead cranes, various tracking controllers have been developed to achieve satisfactory position tracking and swing suppression. However, along with the trolley and girder positions, both sway angles (i.e., swing and skew angles) should be controlled using the forces driving the trolley and girder for satisfactory transient response and safety enhancement through the suppression of sway angles even in the presence of uncertainties in 3-D cranes that have not been a major consideration in previous works. By introducing the sliding surface dependent on position tracking errors and the finite-time stabilization method for the skew angular rate, the proposed SMC-based robust finite-time antisway tracking control method is designed using the terms, each of which achieves position tracking control, antiswing control, and antiskew control. Accordingly, the proposed method can effectively suppress the sway motion of the 3-D crane and work well even with the variation in payload weight, the initial sway angles, and parameter uncertainties due to the payload weight uncertainty. The validity of the proposed method is supported by stability analysis and simulation and experimental results.

Nonlinear Energy-Based Regulation Control of Three-Dimensional Overhead Cranes

To increase the transportation efficiency and ensure the safety of the crane system, the trolley/bridge is required to be driven to reach different preset destinations without retuning control gains of the controller, while the maximum payload swing amplitudes need to be similar for different transportation processes of different distances. Motivated by the desire to achieve these objectives, based on the energy shaping methodology and passivity-based control (PBC), an enhanced coupling control method is derived for three-dimensional (3-D) underactuated overhead cranes. Specifically, on the basis of the energy shaping methodology and PBC, a constructive storage function is constructed by solving partial differential equations. Then, a novel enhanced coupling control scheme enforcing the dissipation inequality with respect to the constructed storage function is investigated straightforwardly, and the corresponding stability analysis is proven by Lyapunov techniques and LaSalle's invariance theorem. Finally, the feasibility and effectiveness of the proposed method is demonstrated by digital simulations and experimental tests.

Nonlinear coupling control method for underactuated three-dimensional overhead crane systems under initial input constraints

In this paper, we present an enhanced coupling nonlinear control method for three-dimensional overhead crane systems under initial input constraints. The proposed control method can achieve superior control performance and strong robustness with respect to system parameter variations and external disturbances. Moreover, it guarantees ‘soft’ trolley start by introducing hyperbolic tangent functions into the controller. More precisely, we enhance the coupling behaviour between the trolley movement and the payload swing by fabricating two composite signals, based on which an energy-like storage function is established. Then, a nonlinear coupling control method under initial input constraints is derived directly. Lyapunov techniques and LaSalle’s invariance theorem are successfully adopted to find the asymptotic stability solution while satisfying the initial input constraints. Strict mathematical analysis of the control scheme with initial input constraints is provided as theoretical support for the superior performance of the controller. Simulation and experimental results are conducted to show the superior performance and strong robustness of the proposed control method.

Direct Adaptive Fuzzy Moving Sliding Mode Proportional Integral Tracking Control of a Three-Dimensional Overhead Crane

In this paper, a novel direct adaptive fuzzy moving sliding mode proportional integral (PI) tracking control of a three-dimensional (3D) overhead crane which is modeled by five highly nonlinear second-order ordinary differential equations is proposed. The fast and robust position regulation and antiswing control can be achieved based on the proposed approach. Due to universal approximation theorem, fuzzy control provides nonlinear controller, i.e., fuzzy logic controllers, to perform the unknown nonlinear control actions. Simultaneously, in order to achieve fast and robust regulation and to enhance robustness in the presence of disturbance and parameter variations, moving sliding mode control (SMC) is introduced to tradeoff between reaching phase and sliding phase. Hence, the sliding surface is moved by changing the magnitude of the slope by adaptive law and varying the intercept by tuning algorithm. Simulations performed using a scaled 3D mathematical model of the crane confirm that the proposed control scheme can keep the horizontal position of the payload invariable and suppress the swing of the payload effectively during the hoisting or lowing process.

Efficient Visual Feedback Method to Control a Three-Dimensional Overhead Crane

This paper presents an efficient method to capture the dynamic movement of a three-dimensional (3-D) overhead crane, enabling it to be controlled by visual feedback in real time with two cheap handy cameras. Two tracking areas and one positioning block in each frame are used to search image features and determine the useful vision information. The depth information of 3-D crane system in images can be also obtained by a tag on the dynamic plant. The presented visual tracking method involves comparison of the lightest or darkest points in the tracking or positioning area of a dynamic object and then computes the necessary trolley position and load swing in 3-D space. Upon tracking, the sensing data are sent to an adaptive fuzzy sliding-mode controller (AFSMC) to derive control power for the crane system. Accordingly, the merits of this AFSMC approach, including robustness of the sliding-mode control and the model-free property of the fuzzy logic for the 3-D crane system, are confirmed. Experimental results verify the improvement of the proposed methodology.

Second-order sliding mode control of a 3D overhead crane with uncertain system parameters

This paper proposes a second-order sliding mode controller for a three-dimensional overhead crane in an extremely complicated operation with uncertain system parameters. Three actuators composed of trolley-moving, bridge-traveling, and cargo-hoisting forces simultaneously drive fine outputs comprising bridge motion, trolley translation, cable length, and two payload swing angles. Simulation and experiment are performed to investigate the controller qualities. The proposed controller asymptotically stabilizes and consistently maintains system response even when some system parameters are extensively varied.

Partial feedback linearization control of a three-dimensional overhead crane

Based on partial feedback linearization, an improved nonlinear controller is analyzed and designed for the three-dimensional motion of an overhead crane. Three control inputs composed of bridge moving, trolley travelling, and cargo hoisting forces are used to drive five state variables consisting of bridge motion, trolley movement, cargo hoisting displacement, and two cargo swing angles. The control scheme is constituted by linearly combining two components that are separately obtained from the nonlinear feedback of actuated and un-actuated states. To verify the quality of the control process, both numerical simulation and experimental study are carried out. The proposed controller asymptotically stabilizes all system states.

Sliding Mode Control of a Three-dimensional Overhead Crane

This paper deals with the sliding mode control of a three-dimensional overhead crane. The model of the crane consists of five highly nonlinear second-order ordinary differential equations. The crane is an underactuated system, which makes the design of its controllers intricate. A sliding mode control scheme is proposed for the crane. This scheme, which guarantees the asymptotic stability of the closed-loop system, has two objectives: position regulation and anti-swing control. The performance of the closed-loop system is simulated using MATLAB. The simulation results indicate that the proposed control scheme works well. In addition, the robustness of the controller with respect to uncertainties in the crane parameters is investigated through simulations. It is found that the controller is robust to changes in the parameters. Moreover, since some of the states of the system are not measurable, a Luenberger-type observer is proposed. Simulation of the controlled system using the observer-based sliding mode controller produced good results.