Design of parameter-scheduled state-feedback controllers using shifting specifications

In this paper,the problem of designing aparameter-scheduled state-feedback controller is investigated. The paper presents an extension of the classical regional pole placement, H2 control and H1 control problems, so as to satisfy new specifications, that will be referred to as shifting pole placement control, shifting H2 control and shifting H1 control, respectively. By introducing some parameters, or using the existing ones, the controller can be designed in such away that different values of the separameters imply different regions where the closed-loop poles are situated, or different performances in the H2 or H1 sense. The proposed approach is derived within the so-called Lyapunov Shaping Paradigm, where a single quadratic Lyapunov function is used for ensuring stability and desired performances in spite of arbitrary parameter time variation. The problem is analyzed in the continuous-time LPV case, oventhough the developed theory could be applied to LTI systems in cases when it is desired to vary the control system performances online. Results obtained in simulation demonstrate the effectiveness and the relevant features of the proposed approach.Peer ReviewedPostprint (published version

Robust fault tolerant control framework using uncertain Takagi-Sugeno fuzzy models

This chapter is concerned with the introduction of a fault tolerant control (FTC) framework using uncertain Takagi-Sugeno (FS) fuzzy models. Depending on how much information is available about the fault, the framework gives rise to passive FTC, active FTC without controller reconfiguration and active FTC with controller reconfiguration. The design is performed using a Linear Matrix Inequality (LMI)-based synthesis that directly takes into account the TS description of the system and its uncertainties. An example based on a mobile robot is used to show the application of this methodologyPeer ReviewedPreprin

Dilated LMI characterization for the robust finite time control of discrete-time uncertain linear systems

This paper provides new dilated linear matrix inequalities (LMIs) characterizations for the finite time boundedness (FTB) and the finite time stability (FTS) analysis of discrete-time uncertain linear systems. The dilated LMIs are later used to design a robust controller for the finite time control of discrete-time uncertain linear systems. The relevant feature of the proposed approach is the decoupling between the Lyapunov and the system matrices, that allows considering a parameter-dependent Lyapunov function. In this way, the conservativeness with respect to previous results is decreased. Numerical examples are used to illustrate the results.Peer ReviewedPostprint (author's final draft

Reliability-aware zonotopic tube-based model predictive control of a drinking water network

A robust economic model predictive control approach that takes into account the reliabilityof actuators in a network ispresented for the control of a drinking water network in the presence of uncertainties in the forecasted demands required forthe predictive control design. The uncertain forecasted demand on the nominal MPC may make the optimization processintractable or, to a lesser extent, degrade the controller performance. Thus, the uncertainty on demand is taken into accountand considered unknown but bounded in a zonotopic set. Based on this uncertainty description, a robust MPC is formulatedto ensure robust constraint satisfaction, performance, stability as well as recursive feasibility throughthe formulation ofan online tube-based MPC and an accompanying appropriate terminal set. Reliability is thenmodelled based on Bayesiannetworks, such that the resulting nonlinear function accommodated in the optimization setup is presented in a pseudo-linearform by means of a linear parameter varying representation, mitigating any additional computational expense thanks to theformulation as a quadratic optimization problem. With the inclusion of a reliability index to the economic dominant cost ofthe MPC, the network users’ requirements are met whilst ensuring improved reliability, therefore decreasing short and longterm operational costs for water utility operators. Capabilities of the designed controller are demonstrated with simulatedscenarios on the Barcelona drinking water networkPeer ReviewedPostprint (published version

Robust economic model predictive control of water transport networks

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, a robust economic model predictive controller is proposed for a water transport network. Considering that forecast of demand is required in the drinking water network (DWN) for future predictions of states in the MPC formulation, robustification of the proposed controller is undertaken considering demand uncertainties as unknown but bounded in a zonotopic set. Based on this uncertainty description, a robust MPC controller is designed that ensures that robust constraint satisfaction, stability and performance under uncertainties is guaranteed. The proposed approach is satisfactorily tested in a part of the Barcelona water transport network.Peer ReviewedPostprint (author's final draft

A set-based prognostics approach for wind turbine blade health monitoring

This paper presents a model-based prognostics procedure using a zonotopic Kalman filter in tandem with a zonotopic set-based propagation of degradation, aiding in the quantification of uncertainties associated with prognostics. The prognostics procedure is then applied to the degradation of a wind turbine blade material subjected to a forecasted bounded set description of wind profile. To facilitate an online condition based implementation, an otherwise nonlinear based Kalman filter from the nonlinear wind turbine model is presented in a pseudolinear form, a polytopic linear parameter varying representation, decreasing computational cost and easing in the propagation of the positive invariant zonotopic uncertainty sets to a reachable set that triggers an end of life. Using this information of health, the remaining useful life with its associated uncertainties can be predicted.Peer ReviewedPostprint (published version

Clustering techniques applied to sensor placement for leak detection and location in water distribution networks

This work presents an optimization strategy that maximizes the leak locatability performance of water distribution networks (WDN). The goal is to characterize and determine a sensor configuration that guarantees a maximum degree of locatability while the sensor configuration cost satisfies a budgetary constraint. The method is based on pressure sensitivity matrix analysis and an exhaustive search strategy. In order to reduce the size and the complexity of the problem the present work proposes to combine this methodology with clustering techniques. The strategy developed in this work is successfully applied to determine the optimal set of pressure sensors that should be installed in a district metered area (DMA) in the Barcelona WDN.Peer ReviewedPostprint (published version

Robust quasi-LPV model reference FTC of a quadrotor UAV subject to actuator faults

A solution for fault tolerant control (FTC) of a quadrotor unmanned aerial vehicle (UAV) is proposed. It relies on model reference-based control, where a reference model generates the desired trajectory. Depending on the type of reference model used for generating the reference trajectory, and on the assumptions about the availability and uncertainty of fault estimation, different error models are obtained. These error models are suitable for passive FTC, active FTC and hybrid FTC, the latter being able to merge the benefits of active and passive FTC while reducing their respective drawbacks. The controller is generated using results from the robust linear parameter varying (LPV) polytopic framework, where the vector of varying parameters is used to schedule between uncertain linear time invariant (LTI) systems. The design procedure relies on solving a set of linear matrix inequalities (LMIs) in order to achieve regional pole placement and H8 norm bounding constraints. Simulation results are used to compare the different FTC strategies.Peer ReviewedPostprint (published version

Health-aware economic MPC for operational management of flow-based networks using bayesian networks

This paper presents a health-aware economic Model Predictive Control (EMPC) approach for the Prognostics and Health Management (PHM) of generalized flow-based networks. The proposed approach consists of the integration of the network reliability model obtained from a Bayesian network in the control model. The controller is then able to optimally manage the supply taking into consideration the distribution of the control effort, to extend the life of the actuators by delaying the network reliability decay as much as possible. It also considers an optimal inventory replenishment policy based on a desired risk acceptability level, leading to the availability of safety stocks for unexpected excess demand in networks. The proposed implementation is illustrated with a real case study corresponding to an aggregate model of the Drinking Water transport Network (DWN) of Barcelona.Peer ReviewedPostprint (published version

Tail motion model identification for control design of an unmanned helicopter

This paper explains the methodology developed to design the yaw control system (heading control system) of the α-SAC UAV. The problem of modeling and controlling the tail motion of this UAV along a desired trajectory is considered. First, the response data of the system are collected during special flight test and a linear time invariant model is extracted by identification techniques. Then, the control system is designed and implemented using a PID feedback/feedforward control method. The technique is tested in simulation and validated in the autonomous flight of the small scale helicopter.Peer ReviewedPostprint (published version