Shuhui Bi

Operator-based robust nonlinear control system design for MIMO nonlinear plants with unknown coupling effects

In this article, operator-based robust nonlinear control system design for multi-input multi-output (MIMO) plants with unknown coupling effects is considered. That is, by using operator-based robust nonlinear control design, coupling effects existing in the MIMO nonlinear plants can be decoupled based on a feedback design and robust right coprime factorisation approach, the coupling effects caused by controllers and plant outputs can be stabilised by using definition of Lipschitz operator and contraction mapping theorem, and output tracking performance can be realised by a tracking design scheme. Finally, a simulation example about temperature control process of 3-input/3-output aluminum plate is given to support the theoretical analysis.

Operator-based robust control design for nonlinear plants with perturbation

In this article, operator-based robust control design for nonlinear plants with perturbation is considered by using robust right coprime factorisation approach. In detail, the property of unimodular operator is studied, and a control design structure is proposed. Based on the proposed design scheme, the designed system is robustly stable. Also, output tracking performance can be realised simultaneously. Finally, the effectiveness of the proposed design scheme is demonstrated by a simulation example.

Operator-based robust nonlinear control and its realization for a multi-tank process by using a distributed control system

In this paper, a robust nonlinear control design method using an operator-based robust right coprime factorization approach and its realization based on a distributed control system (DCS) device are considered for a multi-tank process. In detail, for the multi-tank process, consisting of a water-level process and a water-flow process, theoretical models are developed according to the Bernoulli theorem. Based on the obtained models, a robust nonlinear feedback control design is presented by using robust right coprime factorization for the multi-tank process. Further, from a large-scale industrial application viewpoint, the realization of the designed operator-based robust right coprime factorization controllers is considered by using a DCS device. Because there are some nonlinear functions in the designed controllers which cannot be realized straightforwardly in the DCS device such that the designed controllers need to be realized approximately. That is, there exist some parasitic terms for the approximated realization of the controllers in the real system. As a result, the parasitic terms and processes’ unknown uncertainties should be considered simultaneously. In this paper, a robust condition is derived to guarantee robust stability of the nonlinear feedback control system with the parasitic terms and the uncertainties. Moreover, tracking controller design problem for the multi-tank process is discussed. Finally, by using a DCS device (CENTUM CS3000), experimental results are given to confirm the effectiveness of the proposed design scheme.

Operator-based actuator fault detection system design of a thermal process

In this paper, an operator-based fault detection method for actuator fault of an aluminium plate thermal process is proposed by using operator-based robust right coprime factorisation (RCF) approach. In details, operator-based output tracking and fault detection system design for single input single output (SISO) system is proposed, then the theoretical analysis is extended to multi input multi output (MIMO) system. Based on the proposed design schemes, the output tracking performance can be realised and the actuator fault can be detected. After developing a mathematical model of the three-input three-output aluminium plate thermal process, the proposed design schemes are applied and the effectiveness of that is confirmed by the simulation results.

Operator-based robust control for MIMO non-linear systems with uncertain hysteresis

This paper presents a robust control method for multi-input multi-output (MIMO) non-linear systems with uncertain hysteresis using operator-based robust right coprime factorisation approach. In details, a new operator-based robust control system design is proposed for MIMO non-linear plants preceded by hysteresis and some sufficient conditions are proposed. By using the obtained conditions, the controlled system is robustly stable and the desired output tracking performance can be realised. Finally, simulation is done to validate the effectiveness of the proposed control design method.

Operator-based robust nonlinear control for SISO and MIMO nonlinear systems with PI hysteresis

In this paper, operator based robust nonlinear control for single-input single-output U+0028 SISO U+0029 and multi-input multi-output U+0028 MIMO U+0029 nonlinear uncertain systems preceded by generalized Prandtl-Ishlinskii U+0028 PI U+0029 hysteresis is considered respectively. In detail, by using operator based robust right coprime factorization approach, the control system design structures including feedforward and feedback controllers for both SISO and MIMO nonlinear uncertain systems are given, respectively. In which, the controller design includes the information of PI hysteresis and its inverse, and some sufficient conditions for the controllers in both SISO and MIMO systems should be satisfied are also derived respectively. Based on the proposed conditions, influence from hysteresis is rejected, the systems are robustly stable and output tracking performance can be realized. Finally, the effectiveness of the proposed method is confirmed by numerical simulations.

Practical design scheme for nonlinear systems with unknown bounded perturbations using robust right coprime factorization

In this paper, a nonlinear feedback system with unknown bounded perturbations is considered, and based on robust right coprime factorization a practical design scheme for guaranteeing the system stable is proposed. In contrast with previous methods, the merit of the presenting method in this paper does not require to calculate inverse of a Bezout identity for designing a controller for nonlinear systems. That is, the main idea of this paper is to prove one stabilizing operator to be a unimodular operator, so we can utilize the operator to design a practical scheme for nonlinear systems. An example is involved to illustrate the new design scheme on constructing robust right coprime factorization and then robust stability of nonlinear systems with unknown bounded perturbations is guaranteed.

Operator-based robust decoupling control for MIMO nonlinear systems

In this paper, operator-based robust decoupling control system design for multi-input multi-output (MIMO) nonlinear system is considered. That is, by using the proposed operator based robust decoupling control design, coupling effects existing in the MIMO nonlinear plants can be decoupled based on a feedback design and robust right coprime factorization approach, and the robust stability can be guaranteed. After that, an output tracking system is designed for the stabilizing system and the desired output tracking performance can be realized. Finally, a simulation example about robust control for two-link rigid manipulator is given to support the theoretical analysis.

New Developments on Robust Nonlinear Control and Its Applications

1 Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan 2 School of Design, Engineering and Computing, Bournemouth University, Poole House P316, Talbot Campus, Poole BH12 5BB, UK 3 Shandong Provincial Key Laboratory of Robot and Manufacturing Automation Technology, Institute of Automation, Shandong Academy of Sciences, 19 Keyuan Road, Jinan, Shandong 250064, China 4Department of Electronic and Information Engineering, Zhongyuan University of Technology, Zhongyuan Road No. 41, Zhengzhou 450007, China

Operator based robust nonlinear control for Peltier actuated process by robust right coprime factorization and pre-compensator

In this paper, operator based robust nonlinear control system design is considered for Peltier actuated process by using robust right coprime factorization and pre-compensator. A merit of the operator based approach is the simplicity of analyzing the stability of nonlinear systems. Especially, operator based robust right coprime factorization is one of the most useful methods to analyze and stabilize a nonlinear process. In details, operator based tracking scheme with pre-compensator is designed to control the Peltier actuated process. The effectiveness of the designed system is confirmed by experimental results.