Linear feedback control with prespecified performance measure

A novel procedure is presented to design a linear constant state feedback controller with a prespecified performance measure. The method is an iterative technique based on the sensitivity of a quadratic cost functional with respect to the feedback gains. At each iteration, a Riccati-type algebraic matrix equation is solved to compute the sensitivity expressions needed to update the feedback gains.     

Digital design of variable structure control systems

Reachability conditions are developed for discrete single-input-single-output variable structure control systems described by linear mathematical models in general state-space form to reach a switching function from anywhere in state space. Stability conditions of a sliding mode are investigated. A modified algorithm is proposed to simplify the design procedure. Practical application to a thermal process has been achieved by using the modified algorithm to show the potential for development and practical results are compared with those using the classical PID controller design.     

不同电增压方式对米勒循环柴油机性能影响的模拟研究

利用GT-Power进行建模,探究独立式与一体式两种电增压方式对米勒循环柴油机性能的影响。仿真结果表明:两种电增压都可以拓宽米勒循环的应用范围,一体式电增压适用于过量空气系数高的工况,独立式电增压适用于过量空气系数低的工况。与高转速大进气量工况相比,低转速小进气量工况使用电增压能获得更好的增压效果。     

A combined heuristic approach to dynamic lot sizing problems

A combined heuristic approach for dynamic lot sizing problems has been proposed. The combined heuristic is based on the performance analysis of the Silver-Meal heuristic on different problem sizes and demand patterns. The heuristic performs extremely well on average, and has a worst case performance ratio of two.     

Integrated Fuzzy Robust Controller for Flight Control Design

μ-synthesis is a practical design approach and has been applied successfully to achieve a nominal and robust performance objectives. However, this design method suffers from the complexity of its practical implementation and high computational demand due to its high order dynamics. To overcome this problem, the interaction between fuzzy logic control which is a part of intelligence control theory and μ-synthesis controller is carried out. This is called integrated fuzzy robust controller in this paper. It is obtained by coupling fuzzy pd with μ-synthesis controller through the outer loop. Using this design strategy, we can keep the system performance and robustness even a high order μ-synthesis controller is reduced into second order model. In order to test the effectiveness of this design method, the linear simulation results for a launch vehicle’s attitude control motion are presented at the end of this paper.     

Output feedback control using reduced order models

A method is presented for designing linear output feedback controllers using reduced-order models. These reduced-order models retain only the modes that can be most affected by output feedback. A criterion for determining these modes is also derived. Examples are given to demonstrate the advantage of the proposed method over existing well-known techniques.     

A simulation study on autonomous decentralized mechanism in fish behaviour model

The behaviour of a fish school is considered an interesting phenomenon because a fish school behaves differently in various situations. The paper considers a fish school as an autonomous decentralized system and constructs a mathematical model for the autonomous decentralized mechanism. Simulation results show that, by varying the quantity of information exchange among members in school, the present model describes fish behaviour not only for a school with fixed configuration but also for that with variable form. Furthermore, a remarkable difference in fish trajectory is found between the two schools.     

New public-key cryptosystem

The development of a new public-key cryptosystem is discussed. This system is a hybrid combination of the RSA (Rivest-Shamir-Adleman) and knapsack crypto-systems. The message is encrypted in two stages using the knapsack algorithm followed by the RSA algorithm, and then decrypted in reverse order. The mathematics of the knapsack and RSA algorithms, a security analysis of the hybrid system, and a small computer simulation example are all included. The major advantages of this system, when compared with the knapsack and RSA crypto-systems, are higher speed and greater security.