Mukesh D. Patil

Robust control design for nonlinear Magnetic Levitation System using Quantitative Feedback Theory (QFT)

There is a growing demand for magnetic suspension systems, especially in the field of high accuracy multi-dimensional positioning. Magnetic levitation (Maglev) systems offer many advantages such as frictionless, low noise, the ability to operate in high vacuum environments and so on. Reliable and robust controller synthesis of this system is of great practical interest. Robustness is a key issue in designing a control system for a magnetic levitation as the models are never 100 percent accurate and the uncertainties in the model must be accounted. In the present work, a new approach using quantitative feedback theory (QFT) is presented for design of a robust two degree of freedom controller for magnetic levitation. Experimental tests are conducted to check the reliability and robustness of the designed control system by subjecting it to disturbances. The experimental test results show the control system design to be reliable and robust.

Model Order Reduction of High Order LTI System Using Balanced Truncation Approximation

Most of the mathematical model of industrial applications have very high order,implementation and computation of such system is complicated and time consuming so there is an increasing need for obtaining suitable low order approximations of such systems. Low order models result in several advantages such as reduction in computational complexity and easy analysis of original system structure. This paper proposes a numerically efficient model order reduction method using balanced truncation for high order Linear Time Invariant(LTI) systems. Most important feature of this method is that it provides a bound of the infinity norm of approximation error, using Henkel singular values. This bound is very useful in performance evaluation. The simulation result shows the effectiveness of the proposed scheme to obtain the stable 8th order reduced model from a stable 20th order original system with minimum error bound.

Nonlinear control of a Magnetic Levitation system Using Quantitative Feedback Theory (QFT)

There is a growing demand for magnetic suspension systems, especially in the field of high accuracy multi-dimensional positioning. Magnetic Levitation (Maglev) systems offer many advantages such as frictionless, low noise, the ability to operate in high vacuum environments and so on. Reliable and robust controller synthesis of this system is of great practical interest. Robustness is a key issue in designing a control system for a Magnetic Levitation as the models are never 100 percent accurate and the uncertainties in the model must be accounted. In the present work, a new approach using Quantitative Feedback Theory (QFT) is presented for design of a robust two degree of freedom controller for Magnetic Levitation. Experimental tests are conducted to check the reliability and robustness of the designed control system by subjecting it to disturbances. The experimental test results show the control system design to be reliable and robust.

Reliable and Robust Automated Synthesis of QFT Controller for Nonlinear Magnetic Levitation System Using Interval Constraint Satisfaction Techniques

Robust controller synthesis is of great practical interest and its automation is a key concern in control system design. Automatic controller synthesis is still a open problem. In this paper a new, efficient method has been proposed for automated synthesis of a fixed structure quantitative feedback theory (QFT) controller by solving QFT quadratic inequalities of robust stability and performance specifications. The controller synthesis problem is posed as interval constraint satisfying problem (ICSP) and solved with interval constraint solver (realpaver) [1]. The method is guaranteed to find all feasible controllers of given structure in the search domain. The controller designed using proposed method is experimentally tested on ECP’s Magnetic Levitation system [2] which has open loop stable and unstable configurations.

Design and development of microcontroller based data acquisition system with ethernet communication for nuclear power plants

A nuclear reactor and process control systems consists of various continuous process signals coming from the various sensors and transmitters placed at different locations in the field including hazardous area. The accurate measurement of these process parameters is very important in order to carry out control operation properly. The signals from the sensors or transmitters may be analog or digital. To perform the operation on the signals it is necessary to have the data acquisition system(DAS). There are many DAS available in the market which are not much reliable and rugged to use for such applications, where reliability, ruggedness, easy maintenance, long term support are the main issues. To handle these issues the system is designed using high speed Microcontroller with Ethernet controller ENC28J60. The microcontroller has In-Circuit Serial Programming Facility(ICSP). It is also possible to communicate through LAN so that one can have access and control over the system far away from hazardous area. The measurement of analog signals is very difficult as compared to digital signals because the analog signals are affected by the interference noise, Electro-Static Discharge(ESD) and Electro-Magnetic Interference(EMI). Therefore, the protection of process signal from these interferences is very important. This system is provided with the additional provisions for over voltage, ESD, EMI protection, signal Isolation, interference noise and noise filtering. Therefore, DAS with all above features will be very suitable for the various applications including process industries.