On the controllers' design to stabilize ground resonance helicopter

2019 ◽  
Vol 25 (23-24) ◽  
pp. 2894-2909
Author(s):  
José A. Ignácio da Silva ◽  
Douglas D. Bueno ◽  
Gustavo L. C. M. de Abreu
Keyword(s):  
Broad Class ◽  
Linear Matrix ◽  
Rotor Speed ◽  
Control Approach ◽  
Control Gain ◽  
Controller Gain ◽  
Ground Resonance ◽  
Speed Range ◽  
Alternative Methodology ◽  
Operational Envelope

Ground resonance (GR) in helicopters is a potentially catastrophic instability commonly caused by coalescence of the regressive cyclic blade lag mode with the fuselage motion in certain rotor speed ranges. It can limit the helicopter operational envelope and the design of this type of vehicle can become a difficult task. Although a broad class of actuators allows the use of active and semi-active techniques to design feedback-based control systems, a limited number of works in the literature introduce formulations to compute the controller gain to suppress this phenomenon. Also, commonly, a control approach defines a feedback, particularly to a specific rotor speed. In this context, this work introduces an alternative methodology to design an active control system to stabilize GR of a helicopter. The proposed approach can suppress this instability in all rotor speed ranges by using only one control gain. Two strategies are proposed based on linear matrix inequalities (LMIs). The Lyapunov stability criteria are used and the unstable rotor speed is considered as an uncertain parameter to define an associated convex space. Using convex optimization, a robust control gain is computed until all the unstable rotor speed range is stabilized. Numerical simulations are carried out to demonstrate the effectiveness of this methodology. The results confirm the viability of the proposed approach to design active and semi-active controllers.

Linear Matrix Inequality Robust Tracking Control Conditions for Nonlinear Disturbed Interconnected Systems

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Ali Sghaier Tlili
Keyword(s):  
Tracking Control ◽  
Design Method ◽  
Performance Criterion ◽  
Interconnected Systems ◽  
Linear Matrix ◽  
Robust Tracking Control ◽  
External Disturbances ◽  
Control Approach ◽  
Control Gain ◽  
And Control

The objective of this paper is to develop a robust decentralized observer-based feedback model reference tracking control approach for a class of nonlinear disturbed interconnected systems. The proposed H∞ control and observation design method is formulated within an optimization problem involving linear matrix inequalities (LMIs), efficiently solved by a one-step LMI procedure, to compute the decentralized observation and control gain matrices of each subsystem, and to attenuate the external disturbances affecting the subsystems by minimizing a H∞ performance criterion. A numerical simulation is highlighted on a power system with three-interconnected machines to demonstrate the effectiveness of the developed control approach despite the interconnections between different generators, nonlinearities in the system, and external disturbances.

Robust control design of electric helicopter tail reduction system: Fuzzy and optimal view

2020 ◽  
Vol 26 (9-10) ◽  
pp. 814-829
Author(s):  
Yinfei Zhu ◽  
Han Zhao ◽  
Hao Sun ◽  
Shengchao Zhen ◽  
Zicheng Zhu
Keyword(s):  
Robust Control ◽  
Linear Matrix ◽  
Time Varying ◽  
Control Cost ◽  
Robust Controller ◽  
External Disturbances ◽  
Control Approach ◽  
Reduction System ◽  
Control Gain ◽  
Robust Control Design

The optimal robust control with a fuzzy approach is applied to design the electric helicopter tail reduction system in this article. Firstly, the fuzzy dynamical model of the electric helicopter tail reduction system with uncertainties and external disturbances is established, which may be time varying. Then, we propose a deterministic robust controller (differing from IF-THEN rules in traditional fuzzy control) to solve the uncertain problem in electric helicopter tail reduction systems. The electromechanical system with the proposed controller is proved to be stable via the Lyapunov function. The control gain with an optimal design is considered, which minimizes a fuzzy performance index associated with both the control error and the control cost. Furthermore, simulations compared with linear-matrix-inequality control are made to validate the effectiveness and stability of the optimal robust controller. All results show that the performance of the fuzzy electric helicopter tail reduction system can be always guaranteed by this optimal robust control approach.

A Unified Approach to H∞ Control of Singular Markovian Jump Systems

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Guoliang Wang ◽  
Hongyi Li
Keyword(s):  
Transition Probability ◽  
Markovian Jump Systems ◽  
Linear Matrix ◽  
Markovian Jump ◽  
New Approach ◽  
Control Approach ◽  
Singular Markovian Jump Systems ◽  
Jump Systems ◽  
Bounded Uncertainties ◽  
The Given

This paper considers the H∞ control problem for a class of singular Markovian jump systems (SMJSs), where the jumping signal is not always available. The main contribution of this paper introduces a new approach to a mode-independent (MI) H∞ controller by exploiting the nonfragile method. Based on the given method, a unified control approach establishing a direct connection between mode-dependent (MD) and mode-independent controllers is presented, where both existence conditions are given in terms of linear matrix inequalities. Moreover, another three cases of transition probability rate matrix (TRPM) with elementwise bounded uncertainties, being partially unknown and to be designed are analyzed, respectively. Numerical examples are used to demonstrate the effectiveness of the proposed methods.

Accommodation of Multi-Shaft Gas Turbine Switching Control Gain Tuning Problem to IGV Position

2021 ◽  
Author(s):  
Yujia Ma ◽  
Liu Jinfu ◽  
Linhai Zhu ◽  
Qi Li ◽  
Huanpeng Liu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Optimization Procedure ◽  
Switching Control ◽  
Inlet Guide Vane ◽  
Multi Objective ◽  
Control Gain ◽  
Controller Gain ◽  
Compressor Inlet ◽  
Comprehensive Indicator

Abstract This article aims to discuss the influence of compressor Inlet Guide Vane (IGV) position on gas turbine switching control system gain tuning problem. The distinction between IGV and normally reckoned working conditions is differentiated, and an improved double-layer LPV model is proposed to estimate the protected parameters under various IGV positions. Controller gain tuning is conducted with single and multi-objective intellectual optimization algorithms. Simulation results reveal that normally used multi-objective optimization procedure is unnecessary and time-consuming. While with the comprehensive indicator introduced in this paper, the calculation burden can be greatly eased. This improvement is especially advantageous when tuning work is carried out under multiple IGV positions.

scholarly journals Dissipativity-Based Controller Design for Time-Delayed T-S Fuzzy Switched Distributed Parameter Systems

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaona Song ◽  
Mi Wang ◽  
Shuai Song ◽  
Jingtao Man
Keyword(s):  
Fuzzy Controller ◽  
Controller Design ◽  
Sufficient Conditions ◽  
Fuzzy Model ◽  
Distributed Parameter Systems ◽  
Linear Matrix ◽  
Distributed Parameter ◽  
Time Varying Delay ◽  
Closed Loop Systems ◽  
Control Gain

This paper studies fuzzy controller design problem for a class of nonlinear switched distributed parameter systems (DPSs) subject to time-varying delay. Initially, the original nonlinear DPSs are accurately described by Takagi-Sugeno fuzzy model in a local region. On the basis of parallel distributed compensation technique, mode-dependent fuzzy proportional and fuzzy proportional-spatial-derivative controllers are constructed, respectively. Subsequently, using single Lyapunov-Krasovskii functional and some matrix inequality methods, sufficient conditions that guarantee the stability and dissipativity of the closed-loop systems are presented in the form of linear matrix inequalities, which allow the control gain matrices to be easily obtained. Finally, numerical examples are provided to demonstrate the validity of the designed controllers.

scholarly journals Analysis, Synthesis and Experiments of Networked Platoons with Communication Constraints

2017 ◽  
Vol 29 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Ligang Wu ◽  
Zibao Lu ◽  
Ge Guo
Keyword(s):  
Data Packet ◽  
Linear Matrix ◽  
Multiple Time ◽  
Communication Constraints ◽  
Data Packets ◽  
Controller Gain ◽  
Analysis And Synthesis ◽  
Data Processor ◽  
Vehicle Platoons ◽  
Matched Data

This paper investigates the analysis and synthesis of networked vehicle platoons with communication delays, packet dropouts and disorders. In order to deal with the effects of the communication constraints, we introduce a novel Smart Data Processor (SDP) for each vehicle, by which the latest data packets from logic Data Packet Processor and the matched data packet from its Buffer can be obtained. Based on this mechanism, a leader-predecessor-follower control strategy is proposed. In order to guarantee the asymptotic and string stability, the platoon control problem is transformed into a multi-objective H∞-type synthesis problem with the multiple time-varying delays. A sufficient condition for designing the controller gain is derived by solving a set of linear matrix inequalities. Numerous simulations and experiments with laboratory scale Arduino cars show the efficiency of the proposed methods.

H 2-H∞ Control of Discrete Time Nonlinear Systems Using the SDRE Approach

2011 ◽  
Author(s):  
Xin Wang ◽  
Edwin E. Yaz ◽  
Susan C. Schneider ◽  
Yvonne I. Yaz
Keyword(s):  
Riccati Equation ◽  
Discrete Time ◽  
Steady State Solution ◽  
State Feedback Control ◽  
Disturbance Attenuation ◽  
Performance Criteria ◽  
Linear Matrix ◽  
Time Step ◽  
Control Approach ◽  
The Difference

A novel H2–H∞ State Dependent Riccati Equation control approach is presented for providing a generalized control framework to discrete time nonlinear system. By solving a generalized Riccati Equation at each time step, the nonlinear state feedback control solution is found to satisfy mixed performance criteria guaranteeing quadratic optimality with inherent stability property in combination with H∞ type of disturbance attenuation. Two numerical techniques to compute the solution of the resulting Riccati equation are presented: The first one is based on finding the steady state solution of the difference equation at every step and the second one is based on finding the minimum solution of a linear matrix inequality. The effectiveness of the proposed techniques is demonstrated by simulations involving the control of an inverted pendulum on a cart, a benchmark mechanical system.

scholarly journals Robust Control Design to the Furuta System under Time Delay Measurement Feedback and Exogenous-Based Perturbation

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2131
Author(s):  
Gisela Pujol-Vazquez ◽  
Saleh Mobayen ◽  
Leonardo Acho
Keyword(s):  
Time Delay ◽  
Output Feedback Control ◽  
Linear Matrix ◽  
Control Block ◽  
Control Approach ◽  
Delay Measurement ◽  
Control Objective ◽  
Measurement Feedback ◽  
Robust Control Design ◽  
Delay Dependent

When dealing with real control experimentation, the designer has to take into account several uncertainties, such as: time variation of the system parameters, exogenous perturbation and the presence of time delay in the feedback line. In the later case, this time delay behaviour may be random, or chaotic. Hence, the control block has to be robust. In this work, a robust delay-dependent controller based on H∞ theory is presented by employing the linear matrix inequalities techniques to design an efficient output feedback control. This approach is carefully tuned to face with random time-varying measurement feedback and applied to the Furuta pendulum subject to an exogenous ground perturbation. Therefore, a recent experimental platform is described. Here, the ground perturbation is realised using an Hexapod robotic system. According to experimental data, the proposed control approach is robust and the control objective is completely satisfied.

Nonlinear Two Stage Control Strategy of a Wind Turbine for Mechanical Load and Extreme Moment Reduction

2011 ◽  
Author(s):  
Jonathan Chauvin ◽  
Yann Creff
Keyword(s):  
Control Strategy ◽  
Nonlinear Dynamic ◽  
Mechanical Load ◽  
Dynamic Feedback ◽  
Rotor Speed ◽  
Model Uncertainties ◽  
New Approach ◽  
Control Approach ◽  
Second Stage ◽  
Speed Regulation

This paper presents a new approach for the control of wind turbines. The proposed strategy can be decomposed in two part. In a first stage control strategy, we provide a nonlinear dynamic feedforward strategy for rotor speed regulation along with a nonlinear dynamic feedback to be robust to model uncertainties. It guarantees convergence of the rotor speed to its desired value. This first part only looks at the rotor dynamics and the aerodynamics. The tower dynamics is not taken into account. In a second stage control strategy, we provide a control action that minimize the tower fatigue. The strategy is largely validated for the onshore case. The proposed control approach can be extended to the offshore case and a first validation is proposed.

Robust Active Chatter Control in Milling Processes With Variable Pitch Cutters

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Tao Huang ◽  
Lijun Zhu ◽  
Shengli Du ◽  
Zhiyong Chen ◽  
Han Ding
Keyword(s):  
Nonlinear Differential Equations ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Linear Matrix ◽  
Variable Pitch ◽  
Stability Lobe ◽  
Milling Operations ◽  
Controller Gain ◽  
Chatter Control ◽  
The Stability

Milling chatters caused by the regenerative effect is one of the major limitations in increasing the machining efficiency and accuracy of milling operations. This paper studies robust active chatter control for milling processes with variable pitch cutters whose dynamics are governed by multidelay nonlinear differential equations. We propose a state feedback controller based on linear matrix inequality (LMI) approach that can enlarge multiple stability domains in the stability lobe diagram (SLD) while the controller gain is minimized. Numerical simulations of active magnetic bearing systems demonstrate the effectiveness of the proposed method.

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