Operator-Based Robust Nonlinear Control Design and Analysis of a Semiconductor Refrigeration Device

2017 ◽  
Vol 29 (6) ◽  
pp. 1065-1072 ◽  
Author(s):  
Aihui Wang ◽  
Zhengxiang Ma ◽  
Shengjun Wen ◽  
◽  
◽  
...  
Keyword(s):  
Robust Stability ◽  
Tracking Control ◽  
Control Design ◽  
Aluminum Plate ◽  
Control Performance ◽  
Robust Tracking Control ◽  
Factorization Approach ◽  
Coprime Factorization ◽  
State Observers ◽  
Peltier Device

In this paper, an operator-based robust perfect control for nonlinear semiconductor refrigeration device with uncertainties and perturbation is considered. For the research about the properties of the semiconductor refrigeration, an aluminum plate with Peltier device is very representative. Therefore, the perfect tracking control performance of semiconductor refrigeration can be investigated by using this aluminum plate with Peltier device. Moreover, the operator based robust right coprime factorization (RRCF) approach is convenient in analysis and designing control system of nonlinear plant with uncertainties and perturbation. Based on the above reasons, an operator-based robust tracking control design for nonlinear semiconductor refrigeration device with uncertainties and perturbation is investigated by using an operator-based robust right coprime factorization approach, where the operator-based disturbance and state observers based on nominal plant properties are designed to compensate the effect of uncertainties and perturbation. A realizable operator controller is designed to improve the control performance and to realize the perfect tracking. The sufficient condition of robust stability for the designed system is derived. The robust stability condition ensured that the output tracking performance is realized. Finally, the effectiveness of the proposed design scheme was illustrated by the simulation and experimental results.

Robust Tracking Control for Takagi–Sugeno Fuzzy Systems With Unmeasurable Premise Variables: Application to Tank System

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
H. Ghorbel ◽  
A. El Hajjaji ◽  
M. Souissi ◽  
M. Chaabane
Keyword(s):  
Tracking Control ◽  
Fuzzy Systems ◽  
Design Procedure ◽  
Control Design ◽  
Linear Matrix ◽  
Robust Tracking Control ◽  
Fuzzy Observer ◽  
Tank System ◽  
System States ◽  
Takagi Sugeno

In this paper, a robust fuzzy observer-based tracking controller for continuous-time nonlinear systems presented by Takagi–Sugeno (TS) models with unmeasurable premise variables, is synthesized. Using the H∞ norm and Lyapunov approach, the control design for TS fuzzy systems with both unmeasurable premises and system states is developed to guarantee tracking performance of closed loop systems. Sufficient relaxed conditions for synthesis of the fuzzy observer and the fuzzy control are driven in terms of linear matrix inequalities (LMIs) constraints. The proposed method allows simplifying the design procedure and gives the observer and controller gains in only one step. Numerical simulation on a two tank system is provided to illustrate the tracking control design procedure and to confirm the efficiency of the proposed method.

Nonlinear Perfect Tracking Control for a Robot Arm with Uncertainties Using Operator-Based Robust Right Coprime Factorization Approach

2015 ◽  
Vol 27 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Aihui Wang ◽  
◽  
Dongyun Wang ◽  
Haiquan Wang ◽  
Shengjun Wen ◽  
...  
Keyword(s):  
Tracking Control ◽  
Structural Parameters ◽  
Control System Design ◽  
Robot Arm ◽  
External Disturbances ◽  
Factorization Approach ◽  
Coprime Factorization ◽  
Tracking Condition ◽  
Control Scheme ◽  
Universal Stability

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270001/06.jpg"" width=""300"" />Plant uncertainties compensation</div> In this paper, a robust nonlinear perfect tracking control for a robot arm with uncertainties is proposed by using operator-based robust right coprime factorization approach. In general, there exist unknown modelling errors in measuring structural parameters of the robot arm and external disturbances in real situations. In the present control system design, the effect of the modelling errors and disturbances on the system performance is considered to be uncertainties of the robot arm dynamics. Considering the uncertainties, a robust nonlinear perfect tracking control using operator-based robust right coprime factorization is investigated. That is, first, considering the unknown uncertain plant generates limitations in obtaining the so-called universal stability and tracking conditions, the effect of uncertain plant is compensated by designed operator-based feedback control scheme. Second, a new perfect tracking condition is proposed for improving the trajectory of the robot arm. Finally, the effectiveness of the designed system is confirmed by simulation results. </span>

Hysteresis and Creep Compensation for Piezoelectric Actuators Applied to the Feedforward Control Command of Flexible Structures

2007 ◽  
Author(s):  
Jens Becker ◽  
Thomas Kra¨mer ◽  
Lothar Gaul
Keyword(s):  
Finite Element ◽  
Tracking Control ◽  
Feedforward Control ◽  
Control Design ◽  
Nonlinear Effects ◽  
Small Signal ◽  
Control Performance ◽  
Inverse Filter ◽  
Linear Dynamics ◽  
Control Command

Piezoelectric materials are known to exhibit nonlinear effects if they are operated outside their linear small-signal regime, which significantly degrades the performance of structural control concepts. In this contribution, these nonlinear effects are experimentally investigated in the context of a feedforward control application, where a control command is designed to steer the tip of a cantilever beam by means of a piezoelectric patch actuator from initial to a prescribed desired final stationary deflection. As expected, the encountered nonlinear effects degrade the control performance with increasing applied electrical field. Hence, a modified feedforward control design procedure is proposed. The overall nonlinear system model is recast in a series connection of an input nonlinearity and the linear dynamics of the mechanical structure, which the feedforward control to be designed in two steps: First, a feedforward control for the linear model part is derived based on an approach exploting the notion of flatness in combination with modal analysis of the linear dynamics. It uses the finite-element method to derive the linear dynamics of the piezoelectric structure. Secondly, an inverse filter is designed to compensate for the nonlinear piezoelectric hysteresis and creep effects. By insertion of this inverse filter at the system input, i.e. by filtering the feedforward control, very good tracking control performance is recovered in both small and large-signal operation of the piezoelectric actuator. This filter itself is derived by inversion of a model of the nonlinearities in the discrete-time domain. The chosen model for the hysteresis is based on polynomial approximations of the hysteresis loops, appropriate scaling of these loops to the actual point of operation by keeping track of the input signal reversals and on implementation of the physically motivated Madelung rules that the piezoelectric hysteresis obeys. The creep is found to behave according to a Kelvin-Voigt viscoelastic model. Various experiments for the piezoelectrically actuated beam show that the modified feedforward control design yields very good tracking performance also outside of the small-signal regime by application of the compensation filter. The excellent feedforward tracking control performance predicted by simulations of the full (linear) finite-element model is verified. The designed feedforward control realizes very fast rest-to-rest transition in less than half of the period of the first structural mode. As an interesting application of such a feedforward control, a two-degree-of-freedom control concept combining the presented feedforward control and additional feedback control is investigated. By use of the feedforward control, the feedback can be relatively simple because it is only responsible for disturbance rejection and adding robustness.

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