Liquid Container Transfer Research Articles

Control of Liquid Sloshing Container using Active Force Control Method

This paper presents a robust control method to relieve the sloshing of liquid container transport using Active Force Control (AFC) method. A model of two degree-of-freedom (2-DOF) liquid container transfer was implemented in this research as the main dynamical system to be controlled. The surface of liquid is maintained in a flat position, so that changes the slope of liquid surface countered by changing the acceleration of container. The focus of this research is how to use AFC method being applied to the system, so that it can suppress liquid sloshing. The control scheme were simulated, compare between PID-AFC and pure PID. Simulations has been conducted, the results show that the PID-AFC have superior performance to suppress the sloshing compared with pure PID, especially if disturbance occurred.

Control of Liquid Sloshing Container Using Active Force Control Method

This paper presents a robust control method to relieve the sloshing of liquid container transport using Active Force Control (AFC) method. A model of two degree-of- freedom (2-DOF) liquid container transfer was implemented in this research as the main dynamical system to be controlled. The surface of liquid is maintained in a flat position, so that changes the slope of liquid surface countered by changing the acceleration of container. The focus of this research is how to use AFC method being applied to the system, so that it can suppress liquid sloshing. The control scheme were simulated, compare between PID-AFC and pure PID. Simulations has been conducted, the results show that the PID-AFC have superior performance to suppress the sloshing compared with pure PID, especially if disturbance occurred.

液体入り容器の運搬軌道計画とシミュレーション

This paper describes the liquid container transfer by robot, due to the demand for the conveyance of molten metal in casting processes, for the tray service by robot, and so on. Since a liquid in container can wave greatly by changes of transferring velocity due to the inertial force acting on its own, robots cannot carry the container as a rigid box. Therefore, transferring liquid containers using robots requires a carrying method which prevents content fluid from spilling from the container. The proposed method, TGCW (Trajectory Generation to Control Wave) method, is a feed-forward control to realize the prevention of the spillover of content fluid. To reveal the performance of the TGCW method, we performed the verification simulations using the Explicit-MPS (Moving Particle Simulation) method and the validation experiments using a robot arm. We obtained the result that the proposed method has the effect of reducing the displacement of liquid and the simulation results close to experiments.

Integrated Trajectory Planning and Sloshing Suppression for Three-Dimensional Motion of Liquid Container Transfer Robot Arm

For liquid transfer system in three-dimensional space, the use of multijoint robot arm provides much flexibility. To realize quick point-to-point motion with minimal sloshing in such system, we propose an integrated framework of trajectory planning and sloshing suppression. The robot motion is decomposed into translational motion of the robot wrist and rotational motion of the robot hand to ensure the upright orientation of the liquid container. The trajectory planning for the translational motion is based on cubic spline optimization with free via points that produces smooth trajectory in joint space while it still allows obstacle avoidance in task space. Input shaping technique is applied in the task space to suppress the motion induced sloshing, which is modeled as spherical pendulum with moving support. It has been found through simulations and experiments that the proposed approach is effective in generating quick motion with low amount of sloshing.

6自由度パラレルリンク型アクティブ吸振器付き搬送台車による液体タンクの制振制御

This paper presents a method for damping sloshing in a liquid container during its transfer by a cart that is equipped with an active vibration reducer with six-degree-of-freedom parallel linkage. Sloshing is generated during the liquid container transfer. To damp this sloshing, it is tilted and horizontally moved by the active vibration reducer. The reducer is controlled by a linear quadratic regulator. A weighting matrix of the quadratic performance index is optimized using a genetic algorithm. Gain scheduling is used to apply it to any liquid level of the container. The cart is driven along a straight path on a horizontal plane. The usefulness of the control system is verified through a simulation and experiment.

Damping control of sloshing during liquid container transfer by active vibration reducer with 6-DOF parallel linkage (In the case of straight path on horizontal plane)

Damping control of sloshing during liquid container transfer by active vibration reducer with 6-DOF parallel linkage (In the case of straight path on horizontal plane)

Nonlinear modeling and control of slosh in liquid container transfer via a PPR robot

This paper studies the point-to-point liquid container transfer control problem for a PPR robot. The robot manipulator is represented as three rigid links, and the liquid slosh dynamics are included using a multi-mass-spring model. It is assumed that two forces and a torque applied to the prismatic joints and the revolute joint, respectively, are available as control inputs. The objective is to control the robot end-effector movement while suppressing the sloshing modes. A nonlinear mathematical model that reflects all of these assumptions is first introduced. Then, Lyapunov-based feedback controllers are designed to achieve the control objective. Two cases are considered: partial-state feedback that does not use slosh state information and full-state feedback that uses both robot state and slosh state measurements or estimations. Computer simulations are included to illustrate the effectiveness of the proposed control laws.

Robotically controlled sloshing suppression in point-to-point liquid container transfer

This paper studies the sloshing suppression problem in point-to-point liquid container transfer via a Prismatic–Prismatic–Revolute robot. A multi-mass–spring model is introduced for the characterization of the most prominent liquid-sloshing modes. The control inputs are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is to control the robot end-effector movement while suppressing the sloshing modes. A nonlinear mathematical model that reflects all of these specifications is first derived. Then, a Lyapunov-based nonlinear feedback controller is designed to achieve the control objective. Finally, a simulation example is included to demonstrate the effectiveness of the controller.

Sloshing Suppression Control by Using Model Predictive Control in Liquid Container Transfer System

This paper presents sloshing suppression control of liquid with the desirable-speed transfer. In order to suppress the sloshing, mathematical model comprised of the continuous equation and the pressure equation is used and the sloshing phenomena are analyzed by using Boundary Element Method (BEM). Further, BEM model is transformed into the state-variable model. The proposed model can estimate not only first-order mode sloshing but also higher-order mode sloshing and predict the future behavior of liquid level more exactly. Moreover, the sloshing is suppressed by using Model Predictive Control method (MPC). We were able to move the container under minimum sloshing keeping the desirable speed.

2P1-B27 Sloshing Suppression by Input Shaping Method for Liquid Container Transfer Using Multi-Joint Robot Arm

2P1-B27 Sloshing Suppression by Input Shaping Method for Liquid Container Transfer Using Multi-Joint Robot Arm

635 2次元搬送システムにおける振動抑制を考慮した目標値整形

This paper presents a reference management considering suppression of vibration for two-dimensional (2-D) transfer system. In this paper, the reference is generated by using sequential quadratic programming which minimizes cost function as the tracking error between target point and cart trajectory, and energy of band for fluctuating resonance frequency. The proposed method is able to design 2-D free track which suppresses the vibration, and satisfies constraints of system by nonlinear constraint. The effectiveness of the proposed control is shown through various experiments in a liquid container transfer.

傾動をともなう液体容器搬送における時間周波数解析を用いた液面振動固有周波数の推定と振動制御

傾動をともなう液体容器搬送における時間周波数解析を用いた液面振動固有周波数の推定と振動制御

1112 自律型移動ロボットによる液体タンク搬送における制振経路設計 : 定式化された位置情報を用いた制振経路の修正法(ロボティクス・メカトロニクスIII)

1112 自律型移動ロボットによる液体タンク搬送における制振経路設計 : 定式化された位置情報を用いた制振経路の修正法(ロボティクス・メカトロニクスIII)

Sloshing Suppression Control of Liquid Transfer Systems Considering a 3-D Transfer Path

In plants in many industries, there exist a lot of transfer systems with vibration mechanisms. While transfer without residual vibration is usually demanded in these plants, this requirement necessitates large numbers of sensors and complicated models for control design. Therefore, This work presents a trajectory control design method to suppress residual vibration in transfer systems without the need to directly measure vibration. The proposed method consists of two parts. First, the frequency characteristics of the controller, comprised of control elements with simple structures such as a notch filter and a low-pass filter, are shaped as needed to suppress vibration. Next, various parameters of the control elements are determined by solving an optimization problem with penalty terms expressed by the constraints of both the time and frequency domains. The proposed method is applied to a liquid container transfer system, with special consideration given to the suppression of sloshing (liquid vibration) as well as to the maintenance of a high-speed transfer on the container's three-dimensional transfer path. The obtained controller demonstrates good performance for all demands. The effectiveness of the control design method is shown by experiments.

Damping and Transfer of Liquid in Cylindrical Container Using Curved Path Design and Cart Speed Control

In this paper, sloshing in a cylindrical container caused by a curved path transfer is represented by a spherical pendulum model. The model is used to design the curved path and the cart control system considering the damping of sloshing in the liquid container transfer. Radii of curved path are designed by a preshaping method, and a two-degree-of-freedom control system is applied to control the position and the speed of the container on the cart. The two-degree-of-freedom control system is constructed of feed-forward and feedback parts. The feed-forward control input is derived from the preshaping method, and the feedback part is constructed from a LQ controller and Kalman filter. The effectiveness of the present method has been clarified through experimental and simulation results.

Motion control of liquid container considering an inclined transfer path

Abstract The present paper is concerned with advanced control of liquid container transfer along an inclined transfer path, paying special attention to the suppression of sloshing (liquid vibration). To suppress sloshing in the container during acceleration and deceleration along the inclined transfer path, we present a method to actively control the container's rotational motion. This system is useful for saving space in factories and optimizing foundry processes. The effectiveness of the proposed system is demonstrated through simulations and experiments.

Sloshing Analysis and Control System Design of Molten Metal Transfer by Using CFD.

In recent years, many liquid container transfer systems used for the transfer of molten metal in the casting and steel industries have been studied. However, there are few studies to show the control system design method for real molten metal transfer although there are many for water, and it is highly demanded to realize the system in real plants. This paper gives the control system design method for molten metal transfer by using fluid behavior simulator, and realizes the molten metal transfer system. In order to design a feedback controller, sloshing phenomenon is analyzed by using Computational Fluid Dynamics (CFD) Model, and Hybrid Shape Approach is applied. The effectiveness of the proposed design method is shown through real experiment with water and the control simulations based on CFD with molten metal.

Robust liquid container transfer control for complete sloshing suppression

The paper is concerned with the advanced control of liquid container transfer, with special consideration given to the suppression of sloshing (liquid vibration) while maintaining a high speed of transfer for the container. In order to construct a high speed transfer system for a liquid container that satisfies the reduction of endpoint residual vibration and has a robustness to change in the static liquid level, a suitable nominal model was adopted and an appropriate reference trajectory was determined by the optimization method of Fletcher and Reeves (1964). Based on the above command inputs and using a suitable nominal model, an H/sup /spl infin// feedback control system was applied to this process, and its effectiveness is shown through simulations and experiments. Furthermore, an active control method that takes into account the rotational motion of the container in addition to the linear transfer motion is presented, which can achieve complete suppression of sloshing during the whole transfer process.

A Hybrid Design Method of Velocity Patterns and Container Shapes in Straight Line Level Transport System of 2-Dimiensional Liquid Container.

This paper presents a method to degign the optimum container shape and the appropriate velocity patterns considering the damping of sloshing in liquid container transfer. The slope angle of sidewall of a container is selected to suppress the amplitude of sloshing. Further, the shaped velocity pattern reduces the residual sloshing after the end of acceleration or deceleration of transfer by using a preshaping method. The sloshing phenomena are numerically analyzed by a boundary element method (BEM). The trapezoidal velocity patterns and the optimum container shapes are studied through BEM simulations for various slope angles of the sidewall of the container. In terms of a golden section method, which is a unidimensional search technique, the optimum shape of the container and the trapezoidal velocity pattern were determined by minimizing the maximum amplitude of sloshing under the restriction such as the volume of liquid and the length of free surface of the liquid.

330 3次元搬送軌道を考慮した液体搬送システムのスロッシング抑制制御(アドバンスト制御理論応用I)(OS アドバンスト制御理論応用)

This paper is concerned with the advanced control of liquid container transfer, with special consideration given to the transfer on the three dimensional (3D) transfer path as well as the suppression of sloshing (liquid vibration) while maintaining a high speed of transfer for the container. The controller is designed by the hybrid shaped approach considering both time and frequency characteristics, in order to construct a high-speed transfer system for a liquid container which satisfies various control specifications such as the sloshing suppression, overshoot, settling time and restriction of control input's magnitude.