Ramkrishna Pasumarthy

SY
6papers
69citations
Novelty32%
AI Score19

6 Papers

SYMar 2, 2020
Differentiation and Passivity for Control of Brayton-Moser Systems

Krishna Chaitanya Kosaraju, Michele Cucuzzella, Jacquelien M. A. Scherpen et al.

This paper deals with a class of Resistive-Inductive-Capacitive (RLC) circuits and switched RLC (s-RLC) circuits modeled in Brayton Moser framework. For this class of systems, new passivity properties using a Krasovskii's type Lyapunov function as storage function are presented. Consequently, the supply-rate is a function of the system states, inputs and their first time-derivatives. Moreover, after showing the integrability property of the port-variables, two simple control methodologies called output shaping and input shaping are proposed for regulating the voltage in RLC and s-RLC circuits. Global asymptotic convergence to the desired operating point is theoretically proved for both proposed control methodologies. Moreover, robustness with respect to load uncertainty is ensured by the input shaping methodology. The applicability of the proposed methodologies is illustrated by designing voltage controllers for DC-DC converters and DC networks.

SYMay 2, 2018
On the primal-dual dynamics of Support Vector Machines

Krishna Chaitanya Kosaraju, Shravan Mohan, Ramkrishna Pasumarthy

The aim of this paper is to study the convergence of the primal-dual dynamics pertaining to Support Vector Machines (SVM). The optimization routine, used for determining an SVM for classification, is first formulated as a dynamical system. The dynamical system is constructed such that its equilibrium point is the solution to the SVM optimization problem. It is then shown, using passivity theory, that the dynamical system is global asymptotically stable. In other words, the dynamical system converges onto the optimal solution asymptotically, irrespective of the initial condition. Simulations and computations are provided for corroboration.

SYMay 2, 2018
Differential passivity like properties for a class of nonlinear systems

Krishna Chaitanya Kosaraju, Venkatesh Chinde, Ramkrishna Pasumarthy et al.

In this paper, we derive new passive maps akin to incremental passive maps, for a class of nonlinear systems using dynamic feedback and Krasovskii's method. Further using the passive maps we present a control methodology for stabilization to a desired operating point. This work is illustrated by designing a controller for a nonlinear building heating ventilating and air conditioning (HVAC) subsystem.

SYMay 16, 2017
Position and line-of-sight stabilization of spherical robot using feedforward proportional-derivative geometric controller

Krishna Chaitanya Kosaraju, Arun D. Mahindrakar, Vijay Muralidharan et al.

In this paper we present a geometric control law for position and line-of-sight stabilization of the nonholonomic spherical robot actuated by three independent actuators. A simple configuration error function with an appropriately defined transport map is proposed to extract feedforward and proportional-derivative control law. Simulations are provided to validate the controller performance.

SYSep 9, 2016
Identifying Topology of Power Distribution Networks Based on Smart Meter Data

Jayadev P Satya, Nirav Bhatt, Ramkrishna Pasumarthy et al.

In a power distribution network, the network topology information is essential for an efficient operation of the network. This information of network connectivity is not accurately available, at the low voltage level, due to uninformed changes that happen from time to time. In this paper, we propose a novel data--driven approach to identify the underlying network topology including the load phase connectivity from time series of energy measurements. The proposed method involves the application of Principal Component Analysis (PCA) and its graph-theoretic interpretation to infer the topology from smart meter energy measurements. The method is demonstrated through simulation on randomly generated networks and also on IEEE recognized Roy Billinton distribution test system.

LGNov 19, 2015
A Novel Approach for Phase Identification in Smart Grids Using Graph Theory and Principal Component Analysis

P Satya Jayadev, Aravind Rajeswaran, Nirav P Bhatt et al.

Consumers with low demand, like households, are generally supplied single-phase power by connecting their service mains to one of the phases of a distribution transformer. The distribution companies face the problem of keeping a record of consumer connectivity to a phase due to uninformed changes that happen. The exact phase connectivity information is important for the efficient operation and control of distribution system. We propose a new data driven approach to the problem based on Principal Component Analysis (PCA) and its Graph Theoretic interpretations, using energy measurements in equally timed short intervals, generated from smart meters. We propose an algorithm for inferring phase connectivity from noisy measurements. The algorithm is demonstrated using simulated data for phase connectivities in distribution networks.