Papers by Keyword: Nonlinear System

Abstract: This paper outlines a design process for the bolted joints of the drive train of sheet-fed offset printing presses incorporating statistical data and methods. Sheet-fed offset printing presses are driven by a continuous geared drive train along the length of the press. The bolted joints of the drive train connecting the gears to the cylinders of the press are subjected to high loads, especially during emergency stops. A nonlinear mechanical model of a printing press implemented in Matlab/Simulink is presented which is used to calculate the occurring loads. Measurements of linear and nonlinear system response are presented to support the quality of the mechanical model. The bolted joints between the main drive train gears and cylinders are designed according to current standards. Statistical information based on experimental data is considered during the application of the standardized method. Using the Monte Carlo technique, a more exact description of the joint’s strength is made possible. In this way, the maximum tolerable load for the screw connection is 16% higher than the same result from a standard worst-case calculation.

Abstract: In this paper, a multi-level adaptive control algorithm using parameters self-tuning is proposed for improving the tracking performance of a class of SISO nonlinear systems. This scheme is comprised of the pseudo partial derivative estimation law and the adaptive control law. The adaptive control law is derived from a novel higher order weighted one-step-ahead criterion function which exploits more previous control information. In order to identify the laws’ penalty factors which partly imply the dynamics of the system, an approach of parameters self-tuning is proposed with on-line recursive gradient algorithm. This design is model free and depends directly on the pseudo partial derivative updating on-line with the input and output data Simulation examples are provided to illustrate the effectiveness of the proposed method.

Abstract: In this paper, a nonlinear system with random parameter, which is called stochastic fractional-order complex Lorenz system, is investigated. The Laguerre polynomial approximation method is used to study the system. Then, the stochastic fractional-order system is reduced into the equivalent deterministic one with Laguerre approximation. The ensemble mean and sample responses of the stochastic system can be obtained.

Abstract: The nonlinear dynamic differential equation of 2K-H planetary gear transmission, which takes into consideration of clearance, is presented in this paper. Various Chaotic characteristics of the system are collected, such as the Largest Lyapunov Exponent and the phase locus. Experimental simulation is carried out and the periodic movement, quasi periodic movement and chaotic movement of the system are gotten under different parameters.

Abstract: The project described in this paper is based on sequential development of a temperature controlled weather condition emulator for testing of concrete samples in different temperature levels at varying period of time. The device can be used to test concrete samples when engineer wants to realize the concrete behaviour under extreme conditions such as cold, very high temperature or drastic drops of temperature incurred in a short period and importantly test for concrete samples during hydration. As an initial phase of the development process, entire system architecture is sub-phased to modular form and hence formulated each module for simulation before realizing of the final fabrication of the actual system. The main objective in this phase is to design the electronic circuit to control the attached thermoelectric Peltier which is the main subject of the heat source temperature controller. Since, mathematical modelling of dynamics of the Peltier systems are not well defined and assured to be highly non-linear in behaviour, controlling of the system is driven to be selected by a fuzzy inference engine. Modelling, analysis and simulation of the system dynamics of the Peltier has already been completed in last phase. Design of electronic controller is detailed in the paper with an experimental performance evaluation plot based on extreme loading conditions of the cooling-heating device. Uncertainty incurred in temperature measurements is also provided with experimental data obtained from the proposed system circuit. Characteristics of the proposed emulator are discussed with given significant constrains. Finally, obtained experimental data from the circuit is satisfied with the expected once therefore, this phase can be concluded for developing an optimized fuzzy controller to control the device as final step of the device.

Abstract: This paper is devoted to robust control design for block multilinked nonlinear dynamical systems. Transformation of the block system to the single block system is proposed. For the considered block systems function of Lyapunov is designed. It is proved if the number of controls is equal to or more than the number of state variables of the block, then in the given area the closed-loop system conditions of stability followed controllability conditions. Control design accounts limitations of controls and state variables. Modeling results for nonlinear objects control systems are presented.

Abstract: Based on input-output feedback linearization scheme using the theories of differential geometry, this paper designed a controller for the continuous stirred tank reactor system which is a typical nonlinear, multi-variables, time-varying system. First, continuously different the chosen system outputs until control input appear in the expression. Then, overall linearization can be realized by input variable-substitution if some conditions are satisfied. At last, mature linear control theory is used to control the sub linear system stable. Simulation results show that the proposed control scheme is efficient and the system contains good static, dynamic performance.

Abstract: When we use power line as data carrier, due to the complexity of the PLC network environment, data packet loss frequently, so the paper deal with the iterative learning control for a class of nonlinear systems with measurement dropouts in the PLC, and studies the P-type iterative learning control algorithm convergence issues, the data packet loss is described as a stochastic Bernoulli process, on this basis we given convergence conditions for the P-type iterative learning control algorithm. The theoretically analysis is supported by the simulation of a numerical example; the convergence of ILC can be guaranteed when some output measurements are missing.

Abstract: An adaptive neuro-fuzzy controller of nonlinear systems is presented based on data fusion method. It reduces the input dimension of the controller using data fusion technique and simplifies the fuzzy controller’s design. The fuzzy controller was designed with self-learning of neural networks. The simulation results show that the performance of the system is superior to that using conventional fuzzy controller. It is rewarding for the research on combination of data fusion method and intelligent control technique of nonlinear systems.

Abstract: In this paper the combination of linear and nonlinear models in parallel for nonlinear system identification is investigated. A residuals-based sequential identification algorithm using parallel integration of linear Orthornormal basis filters-Auto regressive with exogenous input (OBFARX) and a nonlinear neural network (NN) models is developed. The model performance is then compared against previously developed parallel OBF-NN model in a nonlinear CSTR case study in extended regions of operation (i.e. extrapolation capability).