A Design Method for Modified Smith Predictors for Non-Minimum-Phase Time-Delay Plants with Feedback Connected Multiple Time-Delays

2008 5th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technolog

Hagiwara

Yamamoto

2008

In this paper, we consider the robust stability condition for single-input/single-output time-delay plants with new class of uncertainties. First of all, we define a class of uncertainties to be considered. The necessary and sufficient robust stability condition for time-delay plants with such class of uncertainties is presented. The relation between the time-delay plant and the nominal time-delay plant to satisfy the robust stability condition is clarified. By using this relation, we will show the necessary and sufficient robust stability condition for the time-delay plant with varying number of right half plane poles.

“…In this section, we present a design method for robustly stabilizing controller satisfying Theorem 3 using the parametrization of all stabilizing modified Smith predictor [16][17][18].…”

Section: Design Methods For Robustly Stabilizing Controllermentioning

confidence: 99%

“…According to [18], the parametrization of all stabilizing modified Smith predictor for non-minimumphase plant G m (s)e −sT is written by…”

Section: Design Methods For Non-minimum-phase Plantmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Robust stability condition for a class of time-delay plants with uncertainty

2008 5th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technolog

Hagiwara

Yamamoto

2008

“…Yamada overcame these problems and proposed the parameterization of all proper internally stabilizing controllers for single-input/single-output minimum-phase plants [8]. The parameterization of all stabilizing controllers in [8] is applied to many control problems such as the parameterization of all stabilizing modified repetitive controllers for minimum-phase plants [10], adaptive control systems [11,12], model feedback control systems [13], parallel compensation technique [14], PI control [15] and PID control [16]. If the parameterization of all stabilizing controllers for multipleinput/multiple-output minimum-phase plants is obtained, results in [10,11,12,13,14,15,16] are expanded for multiple-input/multiple-output minimum-phase plants.…”

Section: Introductionmentioning

confidence: 99%

“…The parameterization of all stabilizing controllers in [8] is applied to many control problems such as the parameterization of all stabilizing modified repetitive controllers for minimum-phase plants [10], adaptive control systems [11,12], model feedback control systems [13], parallel compensation technique [14], PI control [15] and PID control [16]. If the parameterization of all stabilizing controllers for multipleinput/multiple-output minimum-phase plants is obtained, results in [10,11,12,13,14,15,16] are expanded for multiple-input/multiple-output minimum-phase plants. From these viewpoints, Yamada et al examined the parameterization of all stabilizing controllers for multiple-input/multiple-output minimum-phase plants [9].…”

Section: Introductionmentioning

confidence: 99%

A Design Method for Internal Model Controllers for Multiple-Input/Multiple-Output Unstable Plant

Thi

Murakami

et al. 2011

KEM

In the present paper, we examine the parameterization of all stabilizing Internal Model Controllers(IMC) for multiple-input/multiple-output unstable plant. The parameterization problem is theproblem in which all stabilizing controllers for a plant are sought [1, 2, 3, 4, 5, 6, 7, 8, 9]. Since this parameterizationcan successfully search for all proper stabilizing controllers, it is used as a tool for manycontrol problems. However, there exists a problem whether or not stabilizing controllers for unstableplant can be represented by IMC structure. The IMC structure has advantages such as closed-loop stabilityis assured simply by choosing a stable IMC parameter. Additionally, closed-loop performancecharacteristics are related directly to controller parameters, which makes on-line tuning of the IMCvery convenient[6]. The solution to this problem, Morari and Zafiriou[6] examined the parameterizationof all stabilizing IMC for unstable plant. Their parameterization remains difficulties. Their internalmodel is not necessarily proper. In addition, their parameterization includes improper IMC. In order toovercome these problems, Chen et al. proposed a design method for IMC for minimum-phase unstableplant[17]. However, the method proposed by Chen et al. cannot apply for multiple-input/multipleoutputunstable plant. Because many of actual plants are multiple-input/multiple-output plants, consideringfor multiple-input/multiple-output unstable plant is important. In this paper, we propose theparameterization of all proper stabilizing IMC for multiple-input/multiple-output unstable plant suchthat the IMC and the internal model are proper. In addition, we present an application of the result forcontroller design for multiple-input/multiple-output time-delay plant.

A Design Method for Modified PID Control Systems to Attenuate Unknown Disturbances

Hagiwara

Murakami

et al. 2010

KEM

PID(Proportional-Integral-Derivative) controller structure is the most widely used one in industrial applications. Yamada and Hagiwara proposed a design method for modified PID controllers such that modified PID controllers make the control system for unstable plants stable and the admissible sets of P-parameter, I-parameter and D-parameter are independent from each other. When modified PID control systems are applied to real plants, the influence of disturbance in the plant must be considered. In many cases, disturbance in the plant is unknown. It is comparatively easy to attenuate known disturbance, but it is difficult to attenuate unknown disturbances. From a practical viewpoint, it is desirable to design a modified PID control system to attenuate unknown disturbances. However, no paper examines a design method for modified PID control systems to attenuate unknown disturbances. In this paper, we propose a design method for modified PID control systems to attenuate unknown disturbances.