Papers by Keyword: System Identification

Abstract: The control of rotary inverted pendulum is a case of classical robust controller design of non-linear system applications. In the control system design, a precise system model is a pre-requisite for an enhanced and optimum control performance. This paper describes the dynamic system model of an inverted pendulum system. The mathematical model was derived, linearized at the upright equilibrium points and validated using non-linear least square frequency domain identification approach based on measured frequency response function of the physical system. Besides that, a linear quadratic regulator (LQR) controller was designed as the balancing controller for the pendulum. An extensive analysis was performed on the effect of the weighting parameter Q on the static time of arm, balance time of pendulum, oscillation, as well as, response of arm and pendulum, in order to determine the optimum state-feedback control vector, K. Furthermore, the optimum control vector was successfully applied and validated on the physical system to stabilize the pendulum in its upright position. In the experimental validation, the LQR controller was able to keep the pendulum in its upright position even in the presence of external disturbance forces.

Abstract: The authors show an identification device, which was developed at Tomsk polytechnic university. First, the main idea of the identification device is given and then they show its structural representation. Furthermore, three versions of complements are considered in the article. These three versions are compared with each other. In the conclusion authors tell about their further plans connected with the identification device.

Abstract: This paper presents a wavelet-based method of identification modal parameter and damage detection in a free vibration response. An algorithm for modal parameter identification and damage detection is purposed and complex Morlet wavelet is chosen as an analysis wavelet function. This paper only focuses on identification of natural frequencies of the structural system. The method utilizes both undamaged and damage experiment data of free vibration response of the truss structure system. Wavelet scalogram is utilizes for damage detection. The change of energy components for undamaged and damage structure is investigated from the plot of wavelet scalogram which corresponded to the detection of damage.

Abstract: Thermal process usually has the characteristics of nonlinearity and uncertainty, so it is difficult to establish the nonlinear model by the traditional method of describing the dynamic mathematical model of thermal process and accurately implement optimal control of thermal process. This paper provides an identification method of thermal process based on relevance vector machine and firefly algorithm, and the modeling results are compared with those by minimal resource allocation network and support vector regression. The simulation results show that the method is effective, and the model has high accuracy and can be directly used in control algorithm based on the model.

Abstract: System identification is the basis for control system design. For linear time-invariant systems have a variety of identification methods, identification methods for nonlinear dynamic system is still in the exploratory stage. Nonlinear identification method based on neural network is a simple and effective general method that does not require too much priori experience about the system to be identified. Through training and learning, the network weights are corrected to achieve the purpose of system identification. The paper is about the identification of multivariable nonlinear dynamic system based on PID neural network. The structure and algorithm of PID neural network are introduced and the properties and characteristics are analyzed. The system identification is completed and the results are fast convergence.

Abstract: This article deals with the tuning of a simplified non-linear model that represents the dynamic behavior of the manipulator arm PUMA MA2000, where excitation signals formed by a finite sum of harmonics Fourier series were used in order to obtain arm dynamical responses. Initially, non-linear mathematical model is derived by using the Euler-Lagrange notation, and then a simplified nonlinear model is obtained and tuned by using the experimental angular position measurements for waist, shoulder and elbow robot joints.

Abstract: This paper presents the system identification of a prototype of hydraulic platform compare with two methods between the Autoregressive model structure with exogenous input and the Lagrange’s equation with SolidWorks’ simulation analysis tool. The system identification was identified, then the model was employed to simulate the multi-sine input response and the simulation results were compared to the experimental results. It was found that the model was developed using Lagrange’s equation more accurate than the Autoregressive model structure that having percentage best fit of 93.45% for the azimuth angle control and 92.25% for the elevation angle control. Overall, this method could be accepted with a good percentage best fit that compared with experiment results.

Abstract: This paper takes the ship air-cooled AC generator with the radial ventilation system for example, establishes the mathematical model of a generator core and winding temperature by using an equivalent thermal circuit method and the temperature calculation method based on the operating parameters, analyzes the transfer function between the generator stator winding temperature rise and the phase voltage, phase current and reactive power, and finally verifies validity of the mathematical model by the experiment.

Abstract: In the process of high pressure dissolving by Bayer process, High Pressure Digestion Slurry with temperature is the main factor which influencing the percentage of dissolved Al203. Research on temperature model of digesting rarely published; parameter setting and control difficult to achieve desirable effect. In the matlab platform, system identification method, according the output error model to identify model, finally determine the model of alumina High-pressure dissolving temperature model. The recognition results showed that: Step response curve of the second-order model is fitted basically with the online temperature trace which collected by alumina High-pressure digestion in ZHONG ZHOU BRANCH CHALCO, degree of fitting is 86.27%; Algebraic stability criterion verifies that: the root of the system equations are negative, it’s stable. The identification model is reasonable and effectual, provide models for parameter setting and control; improve the control accuracy and percentage of dissolved Al203, reduce energy consumption.

Abstract: This paper proposes an algorithm called multi-objective optimization using differential evolution (MOODE) for providing the optimal mathematical model of flexible beam system. The main reason of developing a flexible beam system is to find an appropriate controller to control the vibration produced by this system. This dynamic system is treated as a black box where the acquired input-output data is used in the modeling processes. Two objective functions are considered for optimization; minimizing the number of term of a model structure and minimizing the mean square error between actual and predicted outputs. Nonlinear auto-regressive with exogenous input (NARX) model is used to represent the mathematical model of the investigated system. To obtain an optimal model for representing the dynamic behavior of flexible beam system, the model validity tests have been applied.