Modified Model-Free Adaptive Control Method Applied to Vibration Control of an Elastic Crane

2019 ◽  
Author(s):  
Hoang Anh Pham ◽  
Dirk Söffker
Keyword(s):  
Adaptive Control ◽  
Control Method ◽  
Structural Information ◽  
Control Strategies ◽  
Control Input ◽  
Tracking Errors ◽  
Adaptive Controllers ◽  
Control Approach ◽  
Model Free ◽  
Controlled Systems

Abstract Model-free adaptive control (MFAC) is a data-driven control approach receiving increased attention in the last years. Different model-free-based control strategies are proposed to design adaptive controllers when mathematical models of the controlled systems should not be used or are not available. Using only measurements (I/O data) from the system, a feedback controller is generated without the need of any structural information about the controlled plant. In this contribution an improved MFAC is discussed for control of unknown multivariable flexible systems. The main improvement in control input calculation is based on the consideration of output tracking errors and its variations. A new updated control input algorithm is developed. The novel idea is firstly applied for controlling vibrations of a MIMO ship-mounted crane. The control efficiency is verified via numerical simulations. The simulation results demonstrate that vibrations of the elastic boom and the payload of the crane can be reduced significantly and better control performance is obtained when using the proposed controller compared to standard model-free adaptive and PI controllers.

A Novel Higher-Order Model-Free Adaptive Control for a Class of Discrete-Time SISO Nonlinear Systems

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Shangtai Jin ◽  
Zhongsheng Hou ◽  
Ronghu Chi
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Discrete Time ◽  
Higher Order ◽  
Control Input ◽  
Order Model ◽  
Control Approach ◽  
Model Free ◽  
Input And Output ◽  
Control Scheme

In this work, a novel higher-order model-free adaptive control scheme is presented based on a dynamic linearization approach for a class of discrete-time single input and single output (SISO) nonlinear systems. The control scheme consists of an adaptive control law, a parameter estimation law, and a reset mechanism. The design and analysis of the proposed control approach depends merely on the measured input and output data of the controlled plant. The control performance is improved by using more information of control input and output error measured from previous sampling time instants. Rigorous mathematical analysis is developed to show the bounded input and bounded output (BIBO) stability of the closed-loop system. Two simulation comparisons show the effectiveness of the proposed control scheme.

Adaptive attitude controller design for tail-sitter unmanned aerial vehicles

2020 ◽  
pp. 107754632092535
Author(s):  
Deyuan Liu ◽  
Hao Liu ◽  
Jiansong Zhang ◽  
Frank L Lewis
Keyword(s):  
Adaptive Control ◽  
Unmanned Aerial Vehicles ◽  
Control Method ◽  
Controller Design ◽  
Dynamic Pressure ◽  
Tracking Errors ◽  
Control Approach ◽  
Aerial Vehicles ◽  
Attitude Tracking ◽  
Mode Transitions

Tail-sitter unmanned aerial vehicles have two flight modes: they can fly long distances at high cruising speeds as fixed-wing aircrafts; or hover, take off, and land vertically as rotary-wing aircrafts. The tail-sitter dynamics involves serious nonlinearities and high uncertainties, especially in the two flight mode transitions. In this article, an adaptive control approach is proposed for a class of tail-sitter unmanned aerial vehicles to achieve the robustness properties. The control torque allocation problem is addressed based on the dynamic pressure in the transition flight. The proposed control method does not need to switch the coordinate system, the controller structure, or the controller parameters in different flight modes. It is proven that the attitude tracking errors can converge into a given neighborhood of the origin in finite time. Simulation results are presented to show the advantages of the proposed adaptive control method.

scholarly journals Multilayer Process Goose Queue (PGQ) formation adjustment approaches based on model-free adaptive control strategies

2018 ◽  
Vol 41 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Bo Yang ◽  
He Li ◽  
Hongguang Li
Keyword(s):  
Adaptive Control ◽  
Large Scale ◽  
Production Systems ◽  
Optimization Problems ◽  
Control Strategies ◽  
Control Approach ◽  
Model Free ◽  
Objective Control ◽  
The Individual ◽  
Model Free Controller

The Process Goose Queue (PGQ) approach has been proposed to solve decomposition-coordination optimization problems of large-scale process production systems. At present, the existing multilayer PGQ formation adjustment is generally performed with model-based optimization approaches that strongly rely on rigorous models of processes and suffer difficulties in dealing with online model identifications. In this paper, we introduce a novel data-driven control approach for multilayer PGQ formation adjustments using model-free adaptive control (MFAC) strategies. The individual PGQ is formulated as a multi-objective control problem before a model-free controller is designed for each layer of the PGQs by taking advantage of the feed-forward control idea and the inter-level coordination matrix. This approach enjoys effectively restraining the vibration propagation among PGQs as well as realizing rapid and timely adjustments of the PGQ formation. Case simulations show the effectiveness of the proposed method.

scholarly journals A Novel Adaptive Control Approach Based on Available Headroom of the VSC-HVDC for Enhancement of the AC Voltage Stability

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3222
Author(s):  
Duc Nguyen Huu
Keyword(s):  
Adaptive Control ◽  
Voltage Stability ◽  
Reactive Power ◽  
Control Method ◽  
Offshore Wind ◽  
Voltage Source ◽  
Long Distance ◽  
Control Approach ◽  
Hvdc System ◽  
Voltage Support

Increasing offshore wind farms are rapidly installed and planned. However, this will pose a bottle neck challenge for long-distance transmission as well as inherent variation of their generating power outputs to the existing AC grid. VSC-HVDC links could be an effective and flexible method for this issue. With the growing use of voltage source converter high-voltage direct current (VSC-HVDC) technology, the hybrid VSC-HVDC and AC system will be a next-generation transmission network. This paper analyzes the contribution of the multi VSC-HVDC system on the AC voltage stability of the hybrid system. A key contribution of this research is proposing a novel adaptive control approach of the VSC-HVDC as a so-called dynamic reactive power booster to enhance the voltage stability of the AC system. The core idea is that the novel control system is automatically providing a reactive current based on dynamic frequency of the AC system to maximal AC voltage support. Based on the analysis, an adaptive control method applied to the multi VSC-HVDC system is proposed to realize maximum capacity of VSC for reactive power according to the change of the system frequency during severe faults of the AC grid. A representative hybrid AC-DC network based on Germany is developed. Detailed modeling of the hybrid AC-DC network and its proposed control is derived in PSCAD software. PSCAD simulation results and analysis verify the effective performance of this novel adaptive control of VSC-HVDC for voltage support. Thanks to this control scheme, the hybrid AC-DC network can avoid circumstances that lead to voltage instability.

Anti-noise model-free adaptive control and its application in the circulating fluidized bed boiler

2020 ◽  
pp. 095965182097937
Author(s):  
Na Dong ◽  
Wenjin Lv ◽  
Shuo Zhu ◽  
Donghui Li
Keyword(s):  
Adaptive Control ◽  
Complete Convergence ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Noise Model ◽  
Good Resistance ◽  
Industrial Systems ◽  
Noise Interference ◽  
Model Free ◽  
Tracking Differentiator

Model-free adaptive control has been developed greatly since it was proposed. Up to now, model-free adaptive control theory has become mature and tends to be an effective solution for complex unmodeled industrial systems. In practical industrial processes, most control systems are inevitably accompanied by noise that will result in indelible error and may further cause inaccurate feedback to the output. In order to solve this kind of problem with model-free technique, this article incorporates an improved tracking differentiator into model-free adaptive control. After that, the anti-noise model-free adaptive control method with complete convergence analysis is proposed. Meanwhile, numerical simulation proves that the improved control method can quickly track a given signal with good resistance to noise interference. Finally, the effectiveness and practicability of the proposed algorithm are verified by experiments through the control of drum water level of circulating fluidized.

Data-driven tracking consensus for a class of unknown nonlinear multi-agent systems

2021 ◽  
pp. 107754632110340
Author(s):  
Jia Wu ◽  
Ning Liu ◽  
Wenyan Tang
Keyword(s):  
Control Method ◽  
Sufficient Conditions ◽  
Data Driven ◽  
The Novel ◽  
Multi Agent Systems ◽  
Tracking Errors ◽  
Agent Systems ◽  
Model Free ◽  
Strongly Connected ◽  
Multi Agent

This study investigates the tracking consensus problem for a class of unknown nonlinear multi-agent systems A novel data-driven protocol for this problem is proposed by using the model-free adaptive control method To obtain faster convergence speed, one-step-ahead desired signal is introduced to construct the novel protocol Here, switching communication topology is considered, which is not required to be strongly connected all the time Through rigorous analysis, sufficient conditions are given to guarantee that the tracking errors of all agents are convergent under the novel protocol Examples are given to validate the effectiveness of results derived in this article

Direct adaptive algorithm for seismic control of damaged structures with faulty sensors

2017 ◽  
Vol 24 (24) ◽  
pp. 5854-5866 ◽  
Author(s):  
Amin Hosseini ◽  
Touraj Taghikhany ◽  
Arash Yeganeh Fallah
Keyword(s):  
Adaptive Control ◽  
Seismic Response ◽  
Structural Damage ◽  
Control Method ◽  
Control Strategies ◽  
Magnetorheological Damper ◽  
Main Concern ◽  
Building Structures ◽  
Steel Moment Resisting Frames ◽  
Seismic Control

In recent decades, the application of semi-active control strategies has gained much attention as a way to reduce the seismic response of civil infrastructures. However, uncertainty in the modeling process of systems with possible partial or total failure during an earthquake is the main concern of engineers about the reliability of this strategy. In this regard, adaptive control algorithms are known as an effective solution to adjust control parameters with different uncertainties. In the current study, the efficiency of the simple adaptive control method (SACM) is investigated to control the seismic response of building structures in the presence of unknown structural damage and fault in the sensors. The method is evaluated in 20-story steel moment resisting frames with different arrangement of smart dampers and sensors with various damage and fault scenarios. The results show that the SACM control system can effectively reduce the maximum inter-story drift of the structure in all different assumed magnetorheological damper arrangements. Furthermore, combination of a Kalman–Bucy filter with the SACM improves robustness of the controller to the uncertainties of sensors faults and damages of structural elements.

A Nonlinear Optimal Control Approach for the Vertical Take-off and Landing Aircraft

2021 ◽  
pp. 2150012
Author(s):  
G. Rigatos
Keyword(s):  
Optimal Control ◽  
Control Method ◽  
Nonlinear Optimal Control ◽  
The Body ◽  
Algebraic Riccati Equation ◽  
Control Input ◽  
Time Step ◽  
Control Approach ◽  
Vtol Aircraft ◽  
Optimal Control Approach

The paper proposes a nonlinear optimal control approach for the model of the vertical take-off and landing (VTOL) aircraft. This aerial drone receives as control input a directed thrust, as well as forces acting on its wing tips. The latter forces are not perpendicular to the body axis of the drone but are tilted by a small angle. The dynamic model of the VTOL undergoes approximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method. For the approximately linearized model, an H-infinity feedback controller is designed. The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the VTOL aircraft. The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the aerial drone, under model uncertainties and external perturbations. For the computation of the controller’s feedback gains, an algebraic Riccati equation is solved at each time-step of the control method. The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the VTOL aircraft, under moderate variations of the control inputs. The stability properties of the control scheme are proven through Lyapunov analysis.

Motion Control of an Omni-Directional Walker for Walking Support

2013 ◽  
pp. 20-28
Author(s):  
Renpeng Tan ◽  
Shuoyu Wang ◽  
Yinlai Jiang ◽  
Kenji Ishida ◽  
Masakatsu G. Fujie
Keyword(s):  
Adaptive Control ◽  
Motion Control ◽  
Control Method ◽  
Center Of Gravity ◽  
Path Tracking ◽  
Reference Trajectory ◽  
Tracking Errors ◽  
Directed Movement ◽  
Load Change

With the increase in the percentage of the population defined as elderly, increasing numbers of people suffer from walking disabilities due to illness or accidents. An omni-directional walker (ODW) has been developed that can support people with walking disabilities and allow them to perform indoor walking. The ODW can identify the user’s directional intention based on the user’s forearm pressures and then supports movement in the intended direction. In this chapter, a reference trajectory is generated based on the intended direction in order to support directed movement. The ODW needs to follow the generated path. However, path tracking errors occur because the center of gravity (COG) of the system shifts and the load changes due to user`s pressure. An adaptive control method is proposed to deal with this issue. The results of simulations indicate that the ODW can accurately follow the user’s intended direction by inhibiting the influence of COG shifts and the resulting load change. The proposed scheme is feasible for supporting indoor movement.

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