A. S. C. Sinha

Stabilization of large-scale non-linear infinite delay systems

The problem of stabilizing a class of large-scale non-linear infinite delay systems is considered. It is shown that exponential stability can be achieved by a suitable choice of state feedback controls of large-scale systems with infinite delay, and that a Lyapunov functional can be constructed by using certain results from J. K. Hales Theory of Functional Differential Equations (1977).

Analysis and control of hybrid-electric vehicles with individual wheel brushless traction motors

Focuses on design, development, demonstration and implementation of a highly efficient drive-by-wire direct-wheel-drive transmissionless propulsion systems for light, medium, and heavy vehicles. The problems to be solved are extremely challenging because a number of longstanding problems in nonlinear analysis and control, optimization and design, manufacturing, technology developments and technology transfer have to be solved in order to develop high-performance diesel-electric powertrains to be deployed in new generations of cars, pickups, trucks, buses and other vehicles. The major emphases are placed on improving fuel economy, reducing emission, attaining the desired vehicle performance, increasing reliability and ruggedness, and decreasing cost and maintenance. Novel control algorithms and innovative methods in design of optimal energy management systems are studied. These optimal energy management systems are needed to attain motion control, diagnostics, and decision making. The decision making and control algorithms were integrated in the optimal energy management systems to control diesel-electric drivetrains. The high-level simulation architecture using advanced software environments (MATLAB and SIMULINK) is developed to perform comprehensive analysis of hybrid-electric vehicles (HEVs). Comprehensive analysis of the basic components of diesel-electric drivetrains are performed. The results of evaluations of diesel-electric drives (diesel-starter/generator-power converters-traction motors) and nonlinear analysis of HEVs with optimal energy management systems are presented.

A constructive algorithm for stabilization of nonlinear neutral time-delayed systems occurring in bioengineering

A criterion is given for the stabilization of the trivial solutions solution of a nonlinear functional differential equation of neutral type occurring in bioengineering under the assumptions of continuity and boundedness of the coefficients. The criterion is a condition on the roots of a certain ‘quasi-polynomial’, i.e. a polynomial in a variable and exponential of that variable. The derivation is based on a constructive algorithm which generates a stabilizing control. The method is illustrated by the construction of stabilizing control for a smooth per suit eye movement system. It is shown that for the synthesis of required control function it is unnecessary in a number of cases to solve the corresponding Riccati matrix equation; rather, it is sufficient to find the roots of a certain ‘quasi-polynomial’, i.e. a polynomial in a variable and exponential of that variable. The model of the smooth pursuit eye movement system can be mathematically described by a set of nonlinear, neutral, functional differenti...

Stability of large-scale hereditary systems with infinite retardations

Abstract In this paper, a general theory for large-scale functional differential systems with finite and infinite retardations is developed by employing the theory of systems of functional differential inequalities. The functional differential inequality for the subsystem with infinite retardation is developed following the results of Coleman and Mizel (1968). Finally, a comparison theorem in the framework of vector Lyapunov function has been employed to investigate the stability of hereditary interconnected systerna. An example to illustrate the results is given.

ASIC memory design of 2-D median filters

An 8-bit VHDL based 2-D median filter is designed using Mentor Graphic tools. The algorithm is based on sorting pixel samples and extracting their median values. The code was synthesized and optimized for an IC layout using CMOS 2 micron technology. The principal organization of the memory elements to store data that perform two dimensional transpose application is presented. A Matlab program for this algorithm was written, tested, and verified on 400/spl times/400 pixel images.

A new EE curriculum in electric vehicle applications

In this paper, we present a curriculum development plan in the Department of Electrical Engineering at the Purdue School of Engineering and Technology at Indianapolis that proposes a major area of emphasis in electric and hybrid electric vehicles. In addition to describing the plan, we present an overview of a feasibility study that is drawn from our recent experiences in teaching a course on the design of electronics for electric vehicles. This course, which was developed under a grant from the Department of Educations Fund for Improvements in Post Secondary Education (FIPSE) program, represents the coordinated efforts of a team of faculty from the Departments of Electrical Engineering and Electrical Engineering Technology. Details of the educational and technical features of the proposed curriculum and the university-industry partnership are described. Student feedback from the trial course is also reported.

Non-linear control algorithm for robot manipulators

A mathematical model of a robot manipulator is described by a set of ordinary, coupled non-linear differential equations. Present theory is insufficient to obtain the exact solution of the equations to control the manipulator. We reduce the complexity of the problem by proposing a model reference system where the Coriolis terms are ignored and where the system of non-linear differential equations is almost decoupled by a careful selection of input torques. We show that the proposed control scheme for the model reference system is stable about a known equilibrium point. We present the simulation study for a two-link rotary manipulator where a model reference system and a control scheme are developed. The simulation results indicate that the solution is stable around a predetermined equilibrium point and that the addition of Coriolis terms in the non-linear differential equation does not change the overall stability of the system. The simulation results indicate that the robot manipulator tracks the desired...

Asymptotic behaviour for some large-scale systems with infinite delay

The aggregation-decomposition method is used to derive sufficient conditions for stability of large-scale systems with infinite delays under structural perturbations described by functional differential equations with finite lags appearing only in the interconnections. Electrical networks consisting of transmission lines interconnected with lumped linear and memoryless nonlinear elements can be represented by the dynamical systems considered in this paper.

VLSI implementation of memory design applied to median filter

The principle organization of memory elements to store data that perform two dimensional transpose applications is presented. The memory element is designed using Mentor graphics software. This memory unit is utilized in the design of two-dimensional median filter. The VHDL code used in the implementation of Median filters is detailed. The overall design and its outcomes are described.

Synchronous reluctance motors: nonlinear analysis and control

We perform the analysis and control of synchronous reluctance motors. Complete mathematical models of synchronous reluctance motors in the machine and in the quadrature, direct and zero variables are developed. In particular, nonlinear differential equations are found. Using these mathematical models, nonlinear controllers are designed to guarantee robust tracking and stability, attain disturbance rejection and desired accuracy. A 40 kW, 100 N-m high-speed synchronous reluctance motor, controlled by a high-performance voltage-fed converter, was designed, built, and tested by the Allison Transmission and Purdue University Indianapolis. Experimental results are reported.