Michela Sorbara

Teleoperation of constrained dynamical systems over a TCP/IP local network

In this paper we present a predictive strategy for teleoperating, through communication channels with unknown and possibly unbounded time-delay, a remotely located pre-compensated plant subject to input and state-related pointwise-in-time constraints. In order to demonstrate its effectiveness, a challenging master/slave teleoperating problem over a local TCP/IP network is formulated. It involves a locally pre-compensated laboratory cart/rod Inverted Pendulum as a remote plant and the problem consists in its wide-range stabilization under constraints on the cart motor voltage and rod angle excursion, while providing tracking performance on the cart position.

A supervisory control strategy for fault tolerance enhancement in networked power systems

In this paper we present a supervisory strategy for load/frequency control problems in networked multi-area power systems based on a recent predictive control approach named parameter governor, which joins in a unique framework reference and offset governor actions. The scheme consists of reconfiguring the nominal frequency set-points and adding offsets on the input terminals of the generation units of each area of the power grid in order to avoid operative constraint violations in response to unexpected load changes and/or failures. Such a reconfiguration capability allows one to enhance the fault tolerability in power grids by exploiting their inherent physical redundancy. The effectiveness of the proposed approach is demonstrated on a four-area power system subject to coordination constraints on maximum frequency deviations, exchanged and generated powers.

Predictive Constrained Teleoperation for Safe Long-Distance Robotic Surgical Operations

In this paper we present a predictive control strategy for teleoperating, through communication channels with unknown and possibly unbounded time-delay, a remotely located robotic system so as to avoid dangerous evolutions or the violation of prescribed operative or safety constraints. In particular, we consider the relevant case of putting bounds on the maximum end-effector tracking error (accuracy constraints) with respect to a nominal path while enforcing also constraints on the maximum contact force exchanged between the end-effector itself and the environment. In order to demonstrate its effectiveness, a master/slave teleoperation simulation is considered. It consists of teleoperating a two-links planar robot under contact force and accuracy constraints through a communication link affected by time-delays.

Fault Tolerance Aspects in Networked Multi-area Power Systems

In this paper we present a supervisory strategy for load/frequency control problems in networked multi-area power systems. The scheme consists of modifying the nominal frequency set-points and adjusting offsets on the nominal Automatic Load-Frequency Control (ALFC) laws of each area in order to avoid operative constraints violations in response to unexpected load changes and/or faults/failures. This aim is accomplished via a recent predictive control approach named Parameter Governor, which joins in a general framework Reference and Offset Governors actions. The effectiveness of the strategy is demonstrated on a two-area power system subject to coordination constraints on maximum frequency deviations and generated and distributed inter-area powers.

A passivity-based command governor control approach

In this paper an extension of the basic Command Governor approach for manipulation of dynamic systems is proposed. This work presents a way to incorporate kinetostatic feedback to the operator maintaining the passivity of the closed-loop system. Preliminary simulation results, without time-delay, are presented showing the theoretically expected effectiveness of the proposed method.

SET-POINTS RECONFIGURATION IN NETWORKED DYNAMICAL SYSTEMS

Abstract In this paper we present a discrete-time predictive coordination strategy for load/frequency control problems in networked multi-area electrical power systems. The aim here is at finding a coordination strategy for the on-line modification of the prescribed set-points of each power generation unit, so as to ensure viable evolutions to the overall networked system, with respect to prescribed operative and safety constraints and despite of load variations and possible faults.