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Parameter uncertainties and unpredictable environmental disturbances reduce control performance of real control systems. For a robust control performance, stability and disturbance rejection are two main concerns that should be addressed in practical controller design problems. This paper presents an analysis to deal with system stability and disturbance rejection control for fractional-order PI (FOPI)...
A natural way of controlling linear systems feedback interconnected with memoryless nonlinearities is canceling this latter with a first feedback loop, and then designing a linear controller for the remaining linear dynamics. Nevertheless, this procedure may provide unsatisfactory performance, and even lead to instability, when the nonlinearity can not be exactly cancelled due to lack of information...
Time-delay naturally appears in many control systems, and it is frequently a source of instability. However, for some systems, the presence of delay can have a stabilizing effect. Therefore, stability and control of time-delay systems is of theoretical and practical importance. Modern control systems usually employ digital technology for controller implementation, i.e. sampled-data control. A time-delay...
Based on the analysis of relative orbit dynamics for GEO (geostationary orbit, GEO) satellite and LQG (Linear Quadratic Gaussian, LQG) algorithm, this paper proposed a station-keeping control method for GEO satellite, which realized north-south station-keeping and west-east station-keeping simultaneously. To further verify the effectiveness of the proposed method, corresponding mathematical simulation...
A class of dual-rate system with a fast control updating rate and a slow output sampling rate is considered. Lifting technology is applied to derive lifted state space model and a subspace equation for dual-rate systems. From the subspace equation, the dual-rate predictive control law is calculated from a set of input/output (I/O) open-loop experimental data and, thus, this approach is data-driven...
The exponentially weighted moving average (EWMA) controller is a popular run-to-run (RtR) control scheme in semiconductor manufacturing because of its effectiveness and simplicity. In this paper we propose an improved variable EWMA controller design method. The optimal discount factor of the EWMA controller is determined by minimizing the mean square error (MSE) of process output at each run. The...
In this paper, we propose a CPG (Central pattern generator) control system by using motor dynamics for the gait planning of the quadruped robot. The CPG model, which includes two DC motors model, has a capability to generate the regular joint angle with complex parameters. CPG unit can generate the stable signal, by using the limit cycle method evaluation. We can change the value of CPG parameters...
In this paper, a class of fractional multi-agent systems with external disturbances is studied. A pinning control strategy is designed for a part of agents of the multi-agent systems without disturbances, and this pinning control can bring multiple agents' states to reaching an expected consensus track. A disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous...
This paper discusses the networked predictive control with communication delay and data loss in feedback channel under limit-bandwidth through a single value. A networked predictive control scheme is used to actively compensate for the communication delay and data loss. Based on the analysis of the closed-loop networked predictive control systems, a design strategy and detail steps is proposed. The...
The paper proposes an approach to the construction of Lyapunov functions, which based on the geometric interpretation of a theorem on asymptotic stability and method of construction control systems with increased potential for robust stability for objects with uncertain parameters in the form of three-parameter structurally stable maps of catastrophe theory. Vector components of antigradient of Lyapunov...
For the structural characteristics of the inverter main circuits usually used in PV grid-connected systems, a novel PV grid-connected power conditioning system(PVPCS) is proposed, in which reactive power compensation and harmonic suppression are integrated. The system can improves not only power quality but also efficiency, and reduces power wasting. The working principle of the system, instantaneous...
In this paper, we analyze the stationary behavior of linear control systems equipped with a random dither quantization. First, we evaluate when and in which sense the stationary distribution of each signal is close to a normal (Gaussian) distribution. Then, we compute their stationary variance based on an approximately invariant probability measure.
The recent increase in popularity of shared mobility systems, in which users take a bicycle or car from a geographically-dispersed public pool in order to complete part of a journey, is due in part to improved technologies for tracking and billing customer journeys. In many schemes, a customer can start and end a journey at different docking stations and is billed according to a set fee structure...
We propose the flight control system of a fixed-wing small UAV for a transition flight in consideration of nonlinearity on its dynamics. The control system consists of controllers for translational motion and rotational motion. The effect of its nonlinear dynamics on a control performance cannot be disregarded when designing a flight control system because it is difficult to linearize the motion with...
Nowadays, usage of optimization methods and techniques in various applications is the key factor of increasing the systems efficiency and performance. In this paper, Proportional-Integral-Derivative (PID) controller optimization in greenhouse lighting control system is studied by tuning PID controller coefficients. The advantages and disadvantages of employing multi-objective optimization methods...
In this paper we propose a controller, based on an extension of Interconnection and Damping Assignment-Passivity Based Control (IDA-PBC) framework, for shaping the whole physical characteristics of a quadrotor and for obtaining a desired interactive behavior between the robot and the environment. In the control design, we shape the total energy (kinetic and potential) of the undamped original system...
In this paper the problem of a quadrotor that physically interacts with the surrounding environment through a rigid tool is considered. We present a theoretical design that allows to exert an arbitrary 3D force by using a standard near-hovering controller that was originally developed for contact-free flight control. This is achieved by analytically solving the nonlinear system that relates the quadrotor...
This paper is concerned with chaos control of the oscillator circuit system. Firstly, the adaptive backstepping method is applied to control chaos, and an adaptive backstepping controller is designed based on the model of oscillator circuit system. Then, by discussing, we obtain that the controller can automatically turn on when the oscillator circuit system is in a chaotic state. Finally, numerical...
Magnetic levitation system is a highly nonlinear and open-loop unstable system. So, control of this system is a challenging problem. In this paper a nonlinear optimal controller based on Hamilton-Jacobi-Bellman Partial Differential Equation (HJB PDE) is designed for this system. Goal of proposed controller is stabilizing the system around a desired point. At first, a measure performance based on energy...
The application of the guided missile seeker is to provide stability to the sensor by isolating it from the missile motion and vibration. The aim of this paper is to present the model of two axes gimbal seeker and improve its performance using proposed fuzzy controller. The equations of gimbals motion are derived using Lagrange equation and the stabilization system is constructed considering the missile...
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