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Because of strong coupling, nonlinear, and time-varying characteristics, it is difficult to control complex spacecraft. By means of combining with controlled object dynamics and performance requirements, characteristic modeling and control approach is an effective way to solve this problem. Aimed at the flexible satellites described by using characteristic modeling approach, with the help of fuzzy...
As the complicated structure of the PV generation systems and variety of application environments, the mismatch and hot spot phenomena caused by partial shade or non-uniform illumination not only heavily affect the output characteristics of photovoltaic arrays, but also create safety and reliability problems. This paper proposes a self-adaptive reconfiguration method based on fuzzy control, introduces...
This paper presents a robust adaptive controller for time-varying systems with unknown dead-zone nonlinearity at the plant input. The controller is designed based on the pole assignment strategy, and it is applicable even to systems in the presence of unmodeled dynamics, bounded external disturbances and time-varying parameters. The global stability is ensured by the proposed controller.
In this paper, a voltage controller is proposed and implemented for grid-connected inverters based on H∞ and repetitive control techniques. A frequency adaptive mechanism is introduced to improve system performance and to cope with grid frequency variations. The repetitive control, based on the internal model principle, offers excellent performance for voltage tracking, as it can deal with a very...
This paper focuses on the reconfigurable flight control problem of aircraft with control effectors failures and damages. The architecture of the reconfigurable control system based on control capability evaluating and reference model adapting is presented firstly. And the baseline control law is designed by the dynamic inversion method. Based on the concept of attainable moments, the control capability...
A new online local modeling method is proposed for fed-batch fermentation processes based on dynamic time warping (DTW) and least squares support vector machine (LS_SVM). In this method, a set of data within the sliding window is set as a query sequence in the current process, and then search for the most similar sub-sequence from the historical batch database to form the training set. At last, this...
In this paper, a novel adaptive neural network control scheme is put forward for a class of SISO nonlinear systems with backlash-like hysteresis, where the hysteresis is modeled by a differential equation in the presence of bounded external disturbances. By using the merit of tangent function and the method of minimal parameterization, the proposed designs need no requirements for the knowledges of...
Distributed robust adaptive control is investigated for a class of stochastic multi-agent systems with unknown time-varying structure parameters, unmodeled dynamics, external disturbances, and interactions among agents. The control goal is to make the states of all the agents converge to a desired function of the population state average (PSA). Due to the fact that only local information is available...
This paper presents a novel design of adaptive sliding mode observer. An adaptive sliding mode observer with a proportional and integral sliding surface is derived and the stability condition of the closed-loop system is established. The proposed adaptive sliding mode observer could reconstruct the unmeasured states and estimate unknown system parameters in real time despite parameter variations and...
Piezoelectric actuators are popularly applied in precision positioning mechanism in Scanning Tunneling Microscope due to its advantage of nanometer resolution. Accurate tracking is difficult to be achieved owing to the intrinsic nonlinear hysteresis of piezoelectric ceramics. An adaptive control scheme combining neural network with traditional PID controller is proposed to improve the performance...
This paper proposes a method of using fuzzy neural network into the security access control model based on the Trust-based access control model (TrustBAC). Under the circumstance of users' confidence changing with the context information, in order to solve the problem of dynamic access control and authorization, this paper provides a new attempt by building a reasonable fuzzy neural network topology...
Traditionally, path planning for robots is modeled as optimization problems. One of the most commonly used optimization strategies is Genetic Algorithm (GA) since it always guarantees a nearly shortest path even a global path can not be obtained within a reasonable time. In fact, the performance enhancement of GA is still an open topic for researchers by designing different genetic operators. In addition...
The sensorless estimation principle of rotor speed and position for PMSM by MRAS is given, simulation models are made, simulation results are obtained. Steady estimation errors of speed and position are analyzed after motor parameters change by simulation, dynamic estimation responses and convergence are analyzed under sudden increasing load. Steady speed estimation error can be restrained by PI controller...
The performance of robust adaptive control system based on traditional revised algorithm is awful in the presence of unmodeled dynamics and the performance will go bad, even be unstable, when the working condition (including the parameter, reference input, and so on) change. This paper designs the multiple models robust adaptive controller to control the discrete single-variable non-minimum phase...
The present paper proposes a tool based on fuzzy Petry Nets for modeling the recurrent of the decision functions. The analysed system- a producer-consumer distributed energy production systems is structured on hierarchical levels and is synchronized in relation with successive external requests. Thus, each hierarchical level is capable to repeatedly carry out a fixed decision scheme and executes this...
In the last years, autonomous and adaptive processes have became more and more important. Even business processes are more complex today. The more complex a system becomes, the more difficult it is to handle changed requirements. This increases the need for adaptation abilities of workflows. In these new workflow systems, autonomy would have great impact regarding the possible usability of such workflows...
The high precision of a piezo-electric positioning stage almost depends on whether the designed controller can effectively compensate the inherent hysteresis phenomenon. In this paper, an adaptive output feedback controller based on a radial basis function neural network (RBFNN) is proposed to eliminate the tracking errors caused by the hysteresis behavior. The observer-based RBFNN is used to online...
To address the problems of network congestion, Active queue management (AQM) is advocated to improve the quality of services (QoS) for Internet. Random early detective (RED) algorithm is one of notably AQM mechanism, because it could reduce the high drop rate of bursty flows, avoid global synchronization among flows and reduces network latency (“ping time”). However, RED requires careful tuning of...
In this article, the author designs a Parrondo's game model of biotic population with the BA scale-free network as its spatial carrier, trying to analyze the individual's competitive and cooperative behaviour. The populational Parrondo's game model includes zero-sum games among individuals and the negative sum-up games between individuals and environment. In terms of zero-sum game relations, four...
An indirect adaptive fuzzy control scheme is developed for a class of uncertain strict-feedback nonlinear systems. The fuzzy approximators are used to design an adaptive fuzzy controller and an adaptive fuzzy identification model, and the unknown parameters are adjusted by the modeling error,the tracking error and its time-varying dead-zone. The size of time-varying dead-zone is adjusted adaptively...
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