scholarly journals A Robust Payload Control System Design for Offshore Cranes: Experimental Study

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 462
Author(s):  
Hwan-Cheol Park ◽  
Soumayya Chakir ◽  
Young-Bok Kim ◽  
Dong-Hun Lee

This paper presents a robust controller design of payload position control for an offshore crane facing disturbance and parametric uncertainties. The offshore operations with cranes while lifting and lowering a payload can be dangerous since safety and efficiency are affected by waves, wind and ocean currents. Such harsh sea conditions put the offshore crane and payload through unwanted disturbances and parametric uncertainties, which requires a robust control system to guarantee reliable performance of these systems. In this paper, we detail a controller designed based on uniformly ultimately bounded (UUB) theory, combined with the input-output linearization control technique (IOLC). The stability of the closed-loop system under the UUB conditions is analyzed using the energy-based Lyapunov function. To evaluate the control performance of the proposed controller, along with an IOLC and an integral sliding mode controller (ISMC), a comparison study is also conducted. The control performance and efficiency of the proposed controller are validated through experiments on an offshore crane model.


1999 ◽  
Vol 11 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta ◽  
Hisashi Matsushita ◽  

This paper describes an analysis of an opto-pneumatic control system and an improvement of control performance of the system. The opto-pneumatic system consists of an optical servo valve, a pneumatic cylinder and a cart. First, we built an analytical model of the system considering a nonlinear friction where exists in sliding parts. And we confirmed the validity of the proposed model by comparing theoretical results with experimental results of the characteristics of optical servo valve and cart position control. Then, we applied a sliding mode control scheme compensating a steady-state disturbance to multi- position control and follow-up control of a cart. By computer simulation, we confirmed that the control performance of opto-pneumatic control system was improved by using this control scheme.



Author(s):  
Wen-Chun Yu ◽  
Gou-Jen Wang

A systematic and simple discrete sliding mode controller design scheme based on the suboptimal approach is presented. The behaviors of the control system can be determined through a preferred performance index. The AC servomotor position control is obtained using only the q-axis voltage control loop. The proposed method is simulated and experimented to verify the capability of this new sliding mode control algorithm. Properties such as easy implementation, fast resonse, and robust to external loads are demonstrated.



Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 747
Author(s):  
Mai The Vu ◽  
Tat-Hien Le ◽  
Ha Le Nhu Ngoc Thanh ◽  
Tuan-Tu Huynh ◽  
Mien Van ◽  
...  

Underwater vehicles (UVs) are subjected to various environmental disturbances due to ocean currents, propulsion systems, and un-modeled disturbances. In practice, it is very challenging to design a control system to maintain UVs stayed at the desired static position permanently under these conditions. Therefore, in this study, a nonlinear dynamics and robust positioning control of the over-actuated autonomous underwater vehicle (AUV) under the effects of ocean current and model uncertainties are presented. First, a motion equation of the over-actuated AUV under the effects of ocean current disturbances is established, and a trajectory generation of the over-actuated AUV heading angle is constructed based on the line of sight (LOS) algorithm. Second, a dynamic positioning (DP) control system based on motion control and an allocation control is proposed. For this, motion control of the over-actuated AUV based on the dynamic sliding mode control (DSMC) theory is adopted to improve the system robustness under the effects of the ocean current and model uncertainties. In addition, the stability of the system is proved based on Lyapunov criteria. Then, using the generalized forces generated from the motion control module, two different methods for optimal allocation control module: the least square (LS) method and quadratic programming (QP) method are developed to distribute a proper thrust to each thruster of the over-actuated AUV. Simulation studies are conducted to examine the effectiveness and robustness of the proposed DP controller. The results show that the proposed DP controller using the QP algorithm provides higher stability with smaller steady-state error and stronger robustness.



2017 ◽  
Vol 18 (10) ◽  
pp. 1624-1634 ◽  
Author(s):  
Xiong-bin Peng ◽  
Guo-fang Gong ◽  
Hua-yong Yang ◽  
Hai-yang Lou ◽  
Wei-qiang Wu ◽  
...  


Author(s):  
Yohan Díaz-Méndez ◽  
Leandro Diniz de Jesus ◽  
Marcelo Santiago de Sousa ◽  
Sebastião Simões Cunha ◽  
Alexandre Brandão Ramos

Sliding mode control (SMC) is a widely used control law for quadrotor regulation and tracking control problems. The purpose of this article is to solve the tracking problem of quadrotors using a relatively novel nonlinear control law based on SMC that makes use of a conditional integrator. It is demonstrated by a motivation example that the proposed control law can improve the transient response and chattering shortcomings of the previous approaches of similar SMC based controllers. The adopted Newton–Euler model of quadrotor dynamics and controller design is treated separately in two subsystems: attitude and position control loops. The stability of the control technique is demonstrated by Lyapunov’s analysis and the effectiveness and performance of the proposed method are compared with a similar integral law, also based on SMC, and validated by tracking control problems using numerical simulations. Simulations were developed in the presence of external disturbances in order to evaluate the controller robustness. The effectiveness of the proposed controller was verified by performance indexes, demonstrating less accumulated tracking errors and control activity and improvement in the transient response and disturbance rejection when compared to a conventional integrator sliding mode controller.



2021 ◽  
pp. 107754632110501
Author(s):  
Ji-Won Lee ◽  
Nguyen Xuan-Mung ◽  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong

In recent years, the boom of the quadcopter industry resulted in a broad range of real-world applications which highlighted the urgent need to improve quadcopter control quality. Typically, external disturbances, such as wind, parameter uncertainties caused by payload variations, or the ground effect, can severely degrade the quadcopter’s altitude control performance. Meanwhile, widely used controllers like the proportional-integral-derivative control cannot guarantee control performance when the system is critically affected by factors that exhibit a high degree of variability with time. In this paper, an adaptive control algorithm is proposed to improve quadcopter altitude tracking performance in the presence of both the ground effect and a time-varying payload. First, we derive an adaptive altitude control algorithm using the sliding mode control technique to account for these uncertainties in the quadcopter dynamics model. Second, we apply Lyapunov theory to analyze the stability of the closed-loop system. Finally, we conduct several numerical simulations and experiments to validate the effectiveness of the proposed method.



Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 657 ◽  
Author(s):  
Uyen Tu Thi Hoang ◽  
Hai Xuan Le ◽  
Nguyen Huu Thai ◽  
Hung Van Pham ◽  
Linh Nguyen

The paper addresses the problem of effectively and robustly controlling a 3D overhead crane under the payload mass uncertainty, where the control performance is shown to be consistent. It is proposed to employ the sliding mode control technique to design the closed-loop controller due to its robustness, regardless of the uncertainties and nonlinearities of the under-actuated crane system. The radial basis function neural network has been exploited to construct an adaptive mechanism for estimating the unknown dynamics. More importantly, the adaptation methods have been derived from the Lyapunov theory to not only guarantee stability of the closed-loop control system, but also approximate the unknown and uncertain payload mass and weight matrix, which maintains the consistency of the control performance, although the cargo mass can be varied. Furthermore, the results obtained by implementing the proposed algorithm in the simulations show the effectiveness of the proposed approach and the consistency of the control performance, although the payload mass is uncertain.



2011 ◽  
Vol 110-116 ◽  
pp. 3176-3183 ◽  
Author(s):  
Mao Hsiung Chiang ◽  
Hao Ting Lin

This study aims to develop a leveling position control of an active PWM-controlled pneumatic isolation table system. A novel concept using parallel dual-on/off valves with PWM control signals is implemented to realize active control and to improve the conventional pneumatic isolation table that supported by four pneumatic cushion isolators. In this study, the cushion isolators are not only passive vibration isolation devices, but also pneumatic actuators in active position control. Four independent closed-loop position feedback control system are designed and implemented for the four axial isolators. In this study, on/off valves are used, and PWM is realized by software. Therefore, additional hardware circuit is not required to implement PWM and not only cost down but also reach control precision of demand. In the controller design, the Fourier series-based adaptive sliding-mode controller with H∞ tracking performance is used to deal with the uncertainty and time-varying problems of pneumatic system. Finally, the experiments on the pneumatic isolation table system for synchronous position and trajectory tracking control, including no-load and loading conditions, and synchronous position control with master-slave method, are implemented in order to verify that the controller for each cushion isolator can realize good position and trajectory tracking performance.



2018 ◽  
Vol 248 ◽  
pp. 02005
Author(s):  
Dirman Hanafi ◽  
Mohamed Najib Ribuan ◽  
Wan HamidahWan Abas ◽  
Hidayat ◽  
Elmy Johana ◽  
...  

This paper presents the online control system application for improving the DC motor performance. DC motor widely used in industries and many appliances. For this aim fuzzy logic controller is applied. The type of fuzzy controller use is an incremental fuzzy logic controller (IFLC). The IFLC is developed by using MATLAB Simulink Software and implemented in online position control system applying RAPCON board as a platform. The experimental results produced the best gains of the IFLC are 1.785, 0.0056955 and 0.01 for error gain (GE), gain of change error (GCE) and gain of output (GCU) respectively. Its produce smaller rise time, peak time, 0% overshoot and smaller settling time. Beside that the IFLC response also able to follow the set point. The controller response parameters values are also acceptable. It means that the IFLC suitable to be use for improving the position control system performance.



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