Control and decision strategy for a class of Markovian jump systems in failure prone manufacturing process

This study investigates control and decision strategy for the failure prone manufacturing process, which is modelled as a two-mode Markovian jump system (MJS). Considering the historical effects on the system, the mode transition rate matrix (MTRM) is time-varying instead of homogeneous. A piecewise homogeneous MJS is thus proposed to characterise this phenomenon, in which the MTRM is homogeneous during certain time intervals but non-homogeneous for the whole time interval. By regarding each homogeneous MTRM as one event, all the MTRMs over the whole time interval will take values in an event set and be governed by a higher-level Markov chain. To ensure such system operates normally with high probability, the decisions including preventive maintenance and corrective maintenance are introduced to adjust the higher level Markov chain. Motivated by this, a new joint performance, consisting of both cost function for decision making and controller design, is developed. Optimal decisions are obtained by an iterative algorithm whose convergence is proved, as well as an optimal controller is designed. The effectiveness of this method is demonstrated by simulations

Nonlinear control of vehicle active suspensions

In this paper an improved nonlinear control law is applied to active suspension systems which are assumed to travel along a rugged road. The proposed control law needs only partially-known information instead of full-known detailed information about road conditions. The goal of this research is to reduce controller’s sensitivity to road disturbance and finally reduce forces transmitted by vehicle body to passengers resulting from a rugged road. The control performance is simulated to illustrate the validity of this design

Guaranteed performance robust Kalman filter for continuous-time Markovian jump nonlinear system with uncertain noise

Robust Kalman filtering design for continuous-time Markovian jump nonlinear systems with uncertain noise was investigated. Because of complexity of Markovian jump systems, the statistical characteristics of system noise and observation noise are time-varying or unmeasurable instead of being stationary. In view of robust estimation, maximum admissible upper bound of the uncertainty to noise covariance matrix was given based on system state estimation performance. As long as the noise uncertainty is limited within this bound via noise control, the Kalman filter has robustness against noise uncertainty, and stability of dynamic systems can be ensured. It is proved by game theory that this design is a robust mini-max filter. A numerical example shows the validity of this design

Robust extended Kalman filter of discrete-time Markovian jump nonlinear system under uncertain noise

This paper examines the problem of robust extended Kalman fIlter design for discrete-time Markovian jump nonlinear systems with noise uncertainty. Because of the existence of stochastic Markovian switching, the state and measurement equations of underlying system are subject to uncertain noise whose covariance matrices are time-varying or un-measurable instead of stationary. First, based on the expression of fIltering performance deviation, admissible uncertainty of noise covariance matrix is given. Secondly, two forms of noise uncertainty are taken into account: Non-Structural and Structural. It is proved by applying game theory that this fIlter design is a robust mini-max fIlter. A numerical example shows the validity of the method

Switching controller design for a class of Markovian jump nonlinear systems using stochastic small-gain theorem

Switching controller design for a class of Markovian jump nonlinear systems with unmodeled dynamics is considered in this paper. Based on the differential equation and infinitesimal generator of jump systems, the concept of Jump Input-to-State practical Stability (JISpS) in probability and stochastic Lyapunov stability criterion are put forward. By using back setpping technology and stochastic small-gain theorem, a switching controller is proposed which ensures JISpS in probability for the jump nonlinear system. A simulation example illustrates the validity of this design

State and mode feedback control for discrete-time Markovian jump linear systems with controllable MTPM

In this note, the state and mode feedback control problems for a class of discrete-time Markovian jump linear systems x0028 MJLSs x0029 with controllable mode transition probability matrix x0028 MTPM x0029 are investigated. In most achievements, controller design of MJLSs pays more attention to state x002F output feedback control for stability, while the system cost in practice is out of consideration. In this paper, we propose a control mechanism consisting of two parts: finite-path-dependent state feedback controller design with which uniform stability of MJLSs can be ensured, and mode feedback control which aims to decrease system cost. Differing from the traditional state x002F output feedback controller design, the main novelty is that the proposed control mechanism not only guarantees system stability, but also decreases system cost effectively by adjusting the occurrence probability of system modes. The effectiveness of the proposed mechanism is illustrated via numerical examples. © 2014 Chinese Association of Automation

Effect of Ultra-fine Traditional Chinese Medicine Compounds on Regulation of Lipid Metabolism and Reduction in Egg Cholesterol of Laying Hens

<div><p>ABSTRACT This study has the objective of investigating the effects of traditional Chinese medicine prescriptions (TCM) on serum lipid, abdominal and hepatic fat percentage, cholesterol content in eggs, and mRNA expression of genes apoA I and apoB100. One hundred and thirty five healthy (300-day-old) layers were randomly assigned to three treatments. The hens in control group were fed with the basal diet. The hens in the experimental groups (TCM 1 and TCM 2) were fed with the basal diet supplemented with 1% TCM 1 and 1% TCM 2 respectively over a period of 60 days. Laying performance and the serum parameters relevant to fat metabolism were measured. The results showed that no significant differences were found in average daily feed intake and egg weight among three treatments. Average daily laying rate in TCM treatments was increased, and the cholesterol content in eggs was decreased. The serum triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in experimental treatments were decreased (p<0.05), while the serum high-density lipoprotein cholesterol (HDL-C) level was increased (p<0.05) compared to the control group. Additionally, abdominal fat percentage decreased in TCM 1 treatment (p<0.05), and hepatic fat percentage decreased in both TCM treatments (p<0.05). The expression of apolipoproteinA I (apoA I) and apolipoproteinB100 (apoB100) mRNA in the liver increased in both TCM treatments (p<0.05). These results suggest that the diet supplemented with TCM could increase the expression of apoA I and apoB100 mRNA in the liver, and decrease lipid content in the serum, and reduce egg cholesterol in layers.</p></div