Compensation of the Nonlinear Effect on Anelectro Hydrostatic Cylinder Driver for the Transit and Rotating Motion Using Bilinear System

2014 ◽  
Vol 875-877 ◽  
pp. 2097-2106
Author(s):  
Rai Wung Park

The transit motion and the rotating motion have highly different effects in a technical systems and have almost nonlinear system behaviors. For the descriptions of their dynamical causes and effects on system, the physical information, which is concerned as a nonlinear mathematic model, has been used. But the corresponding equations are generally not easy to solve in complete form or their solutions are so complicated to see through the coherence. A common way to settle such a problem is to linearize system exactly in a state space or on a operating points with Taylor's series approximately. An advanced method to an approximation is a bilinear system that offers global separations principle. In this paper, an extended application of this theory is given in a modeling and control on the electro hydrostatic cylinder driver with both the transit and rotating motions for the keel system that mostly have not only advantage of high performance, small volume of building and weight but also high nonlinear behavior.

2014 ◽  
Vol 1008-1009 ◽  
pp. 16-21
Author(s):  
Xia Dong ◽  
Li Na Zhang ◽  
Yu Ying Fu ◽  
Cui Lian Ji

This paper has built the mathematic model of the single-phase two-stage photovoltaic(PV) grid-connected system. The model consists of a boost DC/DC converter and a DC/AC inverter with LCL filter. On the basis of the variable step perturbation and observation method(P&O), the boost converter changes the output voltage of the PV array by adjusting the duty cycle to realize the PV maximum power point tracking(MPPT). The inverter system restrains the voltage fluctuation effectively by using feed-forward of the grid voltage and current tracking control technology, which has the high performance in both sinusoidal reference tracking and disturbance rejection. LCL filter improves the dynamic performance and restrains the high harmonics efficiently. The simulation with Matlab soft confirms the effectiveness of the model and control strategy.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.


2000 ◽  
Author(s):  
Xuanyin Wang

Abstract This paper researches on the hydraulic servo system by using ordinary on-off valves. The mathematic model of an asymmetric hydraulic cylinder servo control system is built, and its characteristic is analysed here. To reduce the static and dynamic characteristic differences between forward and reverse motion of asymmetric cylinder, and improve system’s performance, a self-tuning linear quadratic gaussian optimum controller (SLQG) is designed successful. In the end, an asymmetric hydraulic cylinder servo system of paint robot is researched. The result shows that the above method is effective.


Author(s):  
Ali Reza Mehrabian ◽  
S. Vahid Hashemi ◽  
Eric Williams ◽  
Mohammad Elahinia

This paper describes the development of fuzzy systems for modeling the hysteresis behavior of shape memory alloy (SMA) actuators. Due to their simplicity and ease of actuation, SMA actuators are very attractive for applications such as miniature robots for micro manufacturing. However, SMAs have not been widely used for motion control applications due to their nonlinear behavior and control difficulties. One approach to design a position controller for SMA systems is to employ an inverse-model of the system in the control loop to compensate the hysteresis properties of the material. Fuzzy systems, due to their nonlinear learning and adaptation abilities, are good candidates for obtaining inverse-models. In this paper two fuzzy modeling approaches are employed and compared to develop a model for a SMA wire actuator. A set of experiments are conducted to generate the training data. The test stand includes a Nickel-Titanium (TiNi) SMA wire, a position sensor, a bias spring and a current amplifier. By comparing the performance of the two employed fuzzy modeling techniques, it is revealed that the approach based on fuzzy Gustafson-Kessel (GK) clustering shows a better performance in the modeling of the hysteresis in the SMA wire. Thus, GK clustering algorithm is employed to develop the inverse-model for the SMA. The reported results demonstrate the ability of the employed fuzzy algorithm for modeling the hysteresis in the system, and the merits of the introduced inverse-model in the control of the position of the SMA.


Author(s):  
Ramiro J. Chamorro ◽  
Marco E. Sanjuan

This research presents an approach for modeling and control of a hydrogen production plant based in steam reforming of methane (SRM). Many studies in the literature have established some important hydrogen production plant information related to sizing and optimization. This research shows a dynamic model integrated with an industrial control system, which will be able to represent the unified plant data for process variables (temperature, pressure, size, etc.). The plant was optimized using surface response methodology (SRM) to approach a maximum value of hydrogen and a minimum carbon monoxide concentration. The dynamic plant model exhibited high interactions and nonlinear behavior. Hence, a Model predictive control (MPC) strategy was design for the dynamic case, with very good results due to its centralized control structure. Steady-state and dynamic simulations were developed using HYSYS 2006.


Author(s):  
Geovani Bondo ◽  
Chengzhi Yuan ◽  
Chang Duan

Abstract This paper studies the modeling and control of a spherical inverted pendulum (SIP). The SIP is deemed to be a reasonable model for rocket-propelled body and is often used to test advanced control strategies. The mathematic model is derived based on a Quanser two degrees-of-freedom inverted pendulum commercial product. The pendulum is mounted on a five-bar mechanism that is actuated by two rotary servo base units. Unlike conventional assumption that the two motors are allowed to rotate simultaneously, we assume a more challenging scenario that at one time only one motor is working. The system is hence modeled as a switched system as two motors have to be switched in order to balance the pendulum at its unstable equilibrium. Switched controllers, together with a switching strategy are developed to ensure the stability of the system and satisfy a disturbance attenuation performance index. Simulation results are presented to show the effectiveness of the proposed method.


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