scholarly journals Output Feedback Cooperative Dynamic Positioning Control for an Unactuated Floating Object Using Multiple Vessels

2021 ◽  
Vol 9 (5) ◽  
pp. 463
Author(s):  
Guoqing Xia ◽  
Chuang Sun ◽  
Bo Zhao
Keyword(s):  
Output Feedback ◽  
Cooperative Control ◽  
Control Method ◽  
Reference Signal ◽  
Dynamic Positioning ◽  
Model Uncertainties ◽  
Positioning Control ◽  
State Observers ◽  
Control Scheme ◽  
Floating Object

This paper proposes an output feedback cooperative dynamic positioning control scheme for an unactuated floating object using multiple vessels under model uncertainties and environmental disturbances. The floating object is connected to multiple vessels through towlines. At first, nonlinear extended state observers are developed for the floating object and vessels to reconstruct the unmeasured velocity and to estimate the model uncertainties and disturbances. Second, observer-based controllers are designed for the floating object and vessels to drive the floating object to track the reference signal and to achieve the cooperative control of multiple vessels, respectively. The salient features of the proposed control scheme are presented as follows. Firstly, by design the object controller, the tracking performance of the object is improved. Secondly, according to the required force of the floating object, the time-varying formation of vessels is obtained by using the towline attachment geometry of the floating object, control allocation and a towline model. It is shown that all signals in closed-loop system are bounded via Lyapunov analysis. Simulation study is carried out to verify the effectiveness of proposed control method.

Anti-windup reconfigurable control for dynamic positioning vessel with thruster faults

2020 ◽  
Vol 42 (16) ◽  
pp. 3216-3224
Author(s):  
Mingyang Li ◽  
Wenbo Xie ◽  
Jian Zhang
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Input Saturation ◽  
Control Process ◽  
Dynamic Positioning ◽  
Closed Loop System ◽  
Reconfigurable Control ◽  
Positioning Control ◽  
Dynamic Positioning System ◽  
System A

In this study, an anti-windup reconfigurable control method is developed for dynamic positioning vessel in the presence of thruster faults and input saturation. The designed reconfiguration block acting as a virtual thruster aims at hiding the faults from the nominal controller. Also, it is added into the closed-loop system between the nominal controller and the dynamic positioning system. A thruster saturation-failure fault matrix technique is proposed to regard the thruster saturation as thruster fault, meanwhile an auxiliary system is constructed to achieve extra compensation for the adverse effects induced by input saturation. Furthermore, an integral sliding mode control method is presented to accommodate the nonlinear items in the reconfiguration block. An adaptive technique is also employed to preserve robustness against the unknown uncertainties. Finally, a vessel dynamic positioning control process is adopted to evaluate the effectiveness of the proposed method.

scholarly journals Adaptive Fuzzy Containment Control for Uncertain Nonlinear Multiagent Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Yang Yu ◽  
Kang-Hyun Jo
Keyword(s):  
Multiagent Systems ◽  
Output Feedback ◽  
State Feedback ◽  
Control Method ◽  
Directed Graphs ◽  
Lyapunov Stability Theory ◽  
Fuzzy Logic Systems ◽  
Containment Control ◽  
Control Scheme ◽  
Multiple Leaders

This paper considers the containment control problem for uncertain nonlinear multiagent systems under directed graphs. The followers are governed by nonlinear systems with unknown dynamics while the multiple leaders are neighbors of a subset of the followers. Fuzzy logic systems (FLSs) are used to identify the unknown dynamics and a distributed state feedback containment control protocol is proposed. This result is extended to the output feedback case, where observers are designed to estimate the unmeasurable states. Then, an output feedback containment control scheme is presented. The developed state feedback and output feedback containment controllers guarantee that the states of all followers converge to the convex hull spanned by the dynamic leaders. Based on Lyapunov stability theory, it is proved that the containment control errors are uniformly ultimately bounded (UUB). An example is provided to show the effectiveness of the proposed control method.

scholarly journals Adaptive Asymptotic Tracking Control for a Class of Uncertain Switched Systems via Dynamic Surface Technique

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Xuemiao Chen ◽  
Qianjin Zhao ◽  
Chunsheng Zhang ◽  
Jian Wu
Keyword(s):  
Switched Systems ◽  
Tracking Control ◽  
Control Method ◽  
Reference Signal ◽  
Adaptive Controller ◽  
Dynamic Surface Control ◽  
Dynamic Surface ◽  
Adaptive Tracking Control ◽  
Nonlinear Switched Systems ◽  
Control Scheme

A novel adaptive tracking control scheme is proposed for a class of uncertain nonlinear switched systems with perturbations in this paper. The common Lyapunov function method is introduced to handle the switched system in the design process of the desired adaptive controller. In addition, a dynamic surface control method is proposed by employing a nonlinear filter such that the “explosion of complexity” problem existing in the conventional backstepping design can be overcome. Under the presented adaptive controller, all the closed-loop signals are semiglobally bounded, and especially the output signal of the controlled system can follow the given reference signal asymptotically. To show the availability of the presented control scheme, a simulation is given in this paper.

scholarly journals Station-Keeping Control of Autonomous and Remotely-Operated Vehicles for Free Floating Manipulation

2021 ◽  
Vol 9 (11) ◽  
pp. 1305
Author(s):  
Ningning Ding ◽  
Yuangui Tang ◽  
Zhibin Jiang ◽  
Yunfei Bai ◽  
Shixun Liang
Keyword(s):  
Direct Method ◽  
Reference Signal ◽  
Station Keeping ◽  
Remotely Operated Vehicles ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Model Free ◽  
Control Scheme ◽  
System States ◽  
The Time Domain

This paper investigates the station-keeping control of autonomous and remotely-operated vehicles (ARVs) for free-floating manipulation under model uncertainties and external disturbances. A modified adaptive generalized super-twisting algorithm (AGSTA) enhanced by adaptive tracking differentiator (ATD) and reduced-order extended state observer (RESO) is proposed. The ATD is used to obtain the smooth reference signal and its derivative. The RESO is used to estimate and compensate for the model uncertainties and external disturbances in real-time, which enhances the robustness of the controller. The modified AGSTA ensures the fast convergence of the system states and maintains them in a predefined neighborhood of origin without overestimating control gains. Besides, the proposed new variable gain strategy completely avoids the control gains vibrating near the set minimum value. Thanks to the RESO, the proposed controller is model-free and can be easily implemented in practice. The stability of the closed-loop system is analyzed based on Lyapunov’s direct method in the time domain. Finally, the proposed control scheme is applied to the station-keeping control of Haidou-1 ARV, and the simulation results confirm the superiority of the proposed control scheme over the original AGSTA.

Implementation of a single-channel active noise control system with multiple reference sensors

2020 ◽  
Vol 68 (5) ◽  
pp. 358-366
Author(s):  
H.E. Oh ◽  
W.B. Jeong ◽  
C. Hong
Keyword(s):  
Single Channel ◽  
Control Method ◽  
Reference Signal ◽  
Active Noise Control ◽  
Multiple Source ◽  
Weighted Sum ◽  
Reference Signals ◽  
Feedforward Controller ◽  
Channel Control ◽  
Source Signals

When multiple sources contribute competitively to the noise level, multi-channel control architecture is needed, leading to more cost and time for control computation. We, hence, are concerned with a single-channel control method with a single-reference signal obtained from a linear combination of the multiple source signals. First, we selected 3 source signal sensors for the reference signals and the error sensor, selected a proper actuator and designed the controllers: 3 cases of single-channel feedforward controllers with a single-reference signal respectively from the source signals, a multi-channel feedforward controller with the reference signals from the source signals, and the proposed controller with the reference signal from weighted sum of the source signals. The weighting factors and the filter coefficients of the controller were determined by the FxLMS algorithm. An experiment was then performed to confirm the effectiveness of the proposed method comparing the control performance with other methods for a tower air conditioner. The overall sound pressure level (SPL) detected by the error sensor is compared to evaluate their performance. The reduction in the overall SPL was obtained by 4.74 dB, 1.96 dB and 6.62 dB, respectively, when using each of the 3 reference signals. Also, the overall SPL was reduced by 7.12 dB when using the multi-reference controller and by 7.66 dB when using the proposed controller. Conclusively, under the multiple source contribution, a single-channel feed forward controller with the reference signal from a weighted sum of the source signals works well with lower cost than multi-channel feedforward controller.

ICMA: AN EFFICIENT INTEGRATED CONGESTION CONTROL APPROACH

2019 ◽  
Vol 14 ◽  
Author(s):  
Tayyab Khan ◽  
Karan Singh ◽  
Kamlesh C. Purohit
Keyword(s):  
Congestion Control ◽  
Packet Loss ◽  
Control Method ◽  
Multicast Communication ◽  
Bandwidth Utilization ◽  
File Transfer ◽  
Control Approach ◽  
Communication Technique ◽  
Control Scheme ◽  
Multiparty Video Conferencing

Background: With the growing popularity of various group communication applications such as file transfer, multimedia events, distance learning, email distribution, multiparty video conferencing and teleconferencing, multicasting seems to be a useful tool for efficient multipoint data distribution. An efficient communication technique depends on the various parameters like processing speed, buffer storage, and amount of data flow between the nodes. If data exceeds beyond the capacity of a link or node, then it introduces congestion in the network. A series of multicast congestion control algorithms have been developed, but due to the heterogeneous network environment, these approaches do not respond nor reduce congestion quickly whenever network behavior changes. Objective: Multicasting is a robust and efficient one-to-many (1: M) group transmission (communication) technique to reduced communication cost, bandwidth consumption, processing time and delays with similar reliability (dependability) as of regular unicast. This patent presents a novel and comprehensive congestion control method known as integrated multicast congestion control approach (ICMA) to reduce packet loss. Methods: The proposed mechanism is based on leave-join and flow control mechanism along with proportional integrated and derivate (PID) controller to reduce packet loss, depending on the congestion status. In the proposed approach, Proportional integrated and derivate controller computes expected incoming rate at each router and feedback this rate to upstream routers of the multicast network to stabilize their local buffer occupancy. Results: Simulation results on NS-2 exhibit the immense performance of the proposed approach in terms of delay, throughput, bandwidth utilization, and packet loss than other existing methods. Conclusion: The proposed congestion control scheme provides better bandwidth utilization and throughput than other existing approaches. Moreover, we have discussed existing congestion control schemes with their research gaps. In the future, we are planning to explore the fairness and quality of service issue in multicast communication.

scholarly journals Disturbance compensation-based output feedback adaptive control for shape memory alloy actuator system

2021 ◽  
Vol 18 (1) ◽  
pp. 172988142199399
Author(s):  
Xiaoguang Li ◽  
Bi Zhang ◽  
Daohui Zhang ◽  
Xingang Zhao ◽  
Jianda Han
Keyword(s):  
Adaptive Control ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Control Method ◽  
Control Law ◽  
Reference Trajectory ◽  
Disturbance Compensation ◽  
Comparison Results ◽  
Control Scheme ◽  
Actuator System

Shape memory alloy (SMA) has been utilized as the material of smart actuators due to the miniaturization and lightweight. However, the nonlinearity and hysteresis of SMA material seriously affect the precise control. In this article, a novel disturbance compensation-based adaptive control scheme is developed to improve the control performance of SMA actuator system. Firstly, the nominal model is constructed based on the physical process. Next, an estimator is developed to online update not only the unmeasured system states but also the total disturbance. Then, the novel adaptive controller, which is composed of the nominal control law and the compensation control law, is designed. Finally, the proposed scheme is evaluated in the SMA experimental setup. The comparison results have demonstrated that the proposed control method can track reference trajectory accurately, reject load variations and stochastic disturbances timely, and exhibit satisfactory robust stability. The proposed control scheme is system independent and has some potential in other types of SMA-actuated systems.

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