Adult autologous mesenchymal stem cells for the treatment of suspected non-infectious inflammatory diseases of the canine central nervous system: safety, feasibility and preliminary clinical findings

Non-infectious inflammatory diseases of the canine central nervous system (CNS) are common idiopathic disorders grouped under the term meningoencephalomyelitis of unknown origin (MUO). Ante mortem diagnosis is achieved via assessment of clinical signs, magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) analysis, but the definitive diagnosis needs histopathological examination. MUO are mostly considered as autoimmune CNS disorders, so that suppressing the immune reaction is the best management method for patients. Mesenchymal stem cells (MSCs) are under investigation to treat autoimmune and degenerative disorders due to their immunomodulatory and regenerative properties. This study aims to verify the safety, feasibility, and efficacy of MSCs treatment in canine idiopathic autoimmune inflammatory disorders of the CNS

Fault tolerant control allocation for fractional-order systems

In this paper a new fault tolerant control strategy for commensurate Fractional Order time invariant systems is proposed, where only measured system outputs are supposed to be available. The output-feedback Fault Tolerant Control/Control Allocation procedure introduced by Edwards et al. [18] is extended to commensurate Fractional-Order uncertain systems. Both the parametric uncertainty of the system matrix and an extra disturbance term are considered. The policy ensures closed-loop stability throughout the entire closed-loop response of the system even in the presence of actuator reduction in the effectiveness. This is accomplished by incorporating ideas of Fractional Sliding Mode Control, Unknown Input Observers and a fixed Control Allocation method. A convex representation of the problem is created in order to get the controller and observer gains

On the adoption of a fractional-order sliding surface for the robust control of integer-order LTI plants

This paper investigates the possible adoption of a fractional order sliding surface for the robust control of perturbed integer-order LTI systems. It is proved that the standard approach used in Sliding Model Control (SMC) cannot be used and a substantial redesign of the control policy is needed. A novel control strategy is discussed, ensuring that the sliding manifold is hit at an infinite sequence of time instants becoming denser as time grows. Interesting asymptotic properties are derived relatively to the closed loop response in the presence of a wide class of disturbances. It is also proved that the chattering phenomenon may be remarkably alleviated. A careful simulation study is reported using an electromechanical system taken from the literature, which includes also a comparative analysis of performances with respect to standard SMC and second-order SMC

A model-based robust icing detection and estimation scheme for wind turbines

In this paper the problem of model-based icing detection for wind turbines is considered. Based on a robust observer of the rotor angular speed, the increase of inertia and aerodynamic torque due to icing can be detected. Moreover, incorporating an online approximator, the amount of icing can be also estimated. Such estimation can be used to define a threshold with an associated logic to stop the turbine when the icing appears to be too severe. © 2016 EUCA

Detection of screamjet unstart in a hypersonic vehicle model

An observer-based strategy for the detection of engine unstart in a scramjet-powered hypersonic vehicle model is presented in this paper. The occurrence of engine unstart, which is regarded as an actuator fault, causes a transition from an operational vehicle mode in which the engine is controllable to a mode where the vehicle is effectively unpowered. Since this transition is accompanied by an abrupt change in model parameters, the vehicle dynamics is modeled as a switching system. A simple algorithm is derived that detects the occurrence of the transition from “started” to “unstarted” mode by processing only the flight control system data, without relying on engine data or measurement of the airflow across the isolator, which facilitate integration with existing control architectures. The method is shown to possess a certain degree of robustness with respect to perturbation on model parameters. Simulation results show the effectiveness of the proposed approach

A Lyapunov-based diagnosis signal for fault detection robust tracking problem of a class of sampled-data systems.

This paper addresses a novel Lyapunov-based diagnosis signal design for the Robust Fault Detection of a class of Sampled Data systems whose output vector has to follow an assigned reference. The only signal available for measurements is the output variable. A simulation study on a vehicle suspension system is also reported