Coefficient diagram method: Difference between revisions

Revision as of 15:15, 13 August 2014

Revision as of 19:07, 31 January 2015

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In [[control theory]], the '''Coefficientcoefficient diagram method''' (CDM), developed and introduced by [[Prof. Shunji Manabe]] in 1991. CDM is an [[algebra]]ic approach applied to a [[polynomial]] loop in the parameter space, where a special diagram called a "''coefficient diagram''" is used as the vehicle to carry the necessary information, and as the criteriacriterion of good design.<ref>S. Manabe (1998), "''Coefficient Diagram Method''", 14th IFAC Symp. on Automatic Control in Aerospace, Seoul.</ref> The performance of the closed loop system is monitored by the coefficient diagram.

The most considerable advantages of CDM can be listed as follows:<ref>S.E. Hamamci, "''A robust polynomial-based control for stable processes with time delay''", Electrical Engineering, vol: 87, pp.163–172, 2005.</ref>

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Although the main principles of CDM have been known since the 1950s,<ref>D. Graham and R.C. Lathrop, "''The synthesis of optimum transient response: criteria and standard forms''", AIEE Trans., vol:72, pp.273–288, 1953.</ref><ref>P. Naslin, ''Essentials of optimal control'', Boston Technical Publishers, Cambridge, MA, 1969.</ref><ref>A.V. Lipatov and N. Sokolov, "''Some sufficient conditions for stability and instability of continuous linear stationary systems''", Automat. Remote Control, vol:39, pp.1285–1291, 1979.</ref> the first systematic method was proposed by Shunji Manabe.<ref>Y.C. Kim and S. Manabe, "''Introduction to coefficient diagram method''" Proceedings of the SSSC’01, Prague, 2001.</ref> He developed a new method that easily builds a target characteristic polynomial to meet the desired time response. CDM is an algebraic approach combining classical and modern control theories and uses polynomial representation in the mathematical expression. The advantages of the classical and modern control techniques are integrated with the basic principles of this method, which is derived by making use of the previous experience and knowledge of the controller design. Thus, an efficient and fertile control method has appeared as a tool with which control systems can be designed without needing much experience and without confronting many problems.

Many control systems have been designed successfully using CDM,.<ref>S. Manabe, "''A low cost inverted pendulum system for control system education''", The 3rd IFAC Symposium on advances in Control Education, Tokyo, 1994.</ref><ref>S.E. Hamamci, M. Koksal and S. Manabe, "''On the control of some nonlinear systems with the coefficient diagram method''", Proceedings of the 4th Asian Control Conference, Singapore, 2002.</ref> It is very easy to design a controller under the conditions of stability, time ___domain performance and robustness. The close relations between these conditions and coefficients of the characteristic polynomial can be simply determined. This means that CDM is effective not only for control system design but also for controller parameters tuning.

Some Researchers on CDM

1. Prof. Shunji Manabe (Japan)

2. Dr. Young Chol Kim(South Korean)

3. Dr. Serdar Ethem Hamamci (Turkey)

4. Dr. Palaniappan Kanthabhabha (India)

5. Dr. Mohammad Haeri (Iran)

==See also==