Keywords: Networked control system, Multi-agent systems
Abstract: This paper focuses on analysing the robustness of sampled-data systems subject to a cascade-connected structure. Two kinds of networks are considered in this work: (1) the detection network, which models the network of the relative detections by agents' onboard sensors; (2) the communication network, which is used to implement the local transmissions of information. Periodic event-triggered mechanisms (PETMs) are used to avoid continuous-time checking of event-triggering conditions. The maximum allowable sampling periods (MASPs) and maximum allowable checking periods (MACPs) are determined to guarantee the strong integral-input-to-state stability of the closed-loop system. Finally, a numerical example is presented to illustrate the effectiveness of the proposed methods.

Keywords: Multi-agent systems, Communication networks, Transportation systems
Abstract: Autonomous intersection control received particular interest recently. Theoretically, such traffic light-free controls can greatly improve the throughput of intersections with autonomous vehicles. The objective of this paper is to show how even a simple intersection control algorithm is susceptible to communication imperfections through detailed modeling of the communication layers. Safety and sensitivity analyses were carried out using a distributed control architecture, where no central control units are present. The control relies only on data contained in standard Cooperative Awareness Messages. The vehicle ad-hoc network communication is simulated with multiple layers considering many critical factors like signal propagation, noise, channel load, and even faulty units. Simulation results suggest that autonomous intersection control is robust against minor faults or communication errors. On the other hand, significant communication breakdowns lead to collisions.

Keywords: Fault tolerant control / fault recovery, Model-based methods, Multi-agent systems
Abstract: In distributed predictive control structures, communication among agents is required to achieve a consensus and approach an optimal global behavior. Such negotiation mechanisms are sensitive to attacks on these exchanges. This paper proposes a monitoring scheme that detects and mitigates these attacks' effects in a resource allocation framework. The performance of the proposed method is illustrated through simulations of the temperature control of multiple rooms under power scarcity.

Keywords: Health monitoring, Model-based methods
Abstract: This work compares the simulated degradation produced at the drive-train of a given wind turbine when it is functioning at optimal and sub-optimal operating points. The simulation considers different classes of wind conditions and supposes the use of the same Maximum Power Point Tracking (MPPT) algorithm but calibrated with different feedback gains. The dissipation at the drive-train is modeled using contact mechanics principles, and it is intended for modeling the mechanical fatigue due to changes in wind speed and turbulence. The paper presents the proposed model for the drive-train degradation and the obtained power curves for a simulated variable-speed 2MW (100m rotor diameter) wind turbine, with fixed gear box and horizontal-axis.

Keywords: Decision making, Health monitoring, Mining and mineral processing
Abstract: Predictive maintenance strategies for the mining sector are of utmost importance considering the automated behavior of industrial systems and the oftentimes inaccessible environment around belt conveyor systems. In this paper, we present a model combining IoT sensors and dead-reckoning modeling, focused on early theoretical work in the field of modeling the behavior of belt conveyor systems to act as a decision support tool in maintenance strategies, by estimating the remaining useful life (RUL) of rotating components in a belt conveyor system. The estimation of RUL is a function of the degradation of the ball bearings in idler rollers due to the forces acting on the rollers during the conveyance of material. The forces occur due to the material loading, the belt weight, roller shell weight, and the idler misalignment load (IML). Furthermore, the dynamics of bulk material during conveyance can be modeled in several ways considering earth pressure theory. A model considering this is derived from the Krausse Hettler method to determine the forces acting on the wing rollers of a thee-roll idler trough set by the notion that the bulk material undergoes active and passive stress states during conveyance. The model is further compared and extended to the works of Sokolovski, to get a bounded delta RUL reduction estimate on the roller bearings in each idler set of a belt conveyor system.

Keywords: Model-based methods
Abstract: Modern manufacturing systems are subject to many disruptions due to increased competition. They are subject to many configuration changes during their life cycle and must cost-effectively make these changes. Intelligent component-based development enables the rapid design of control systems. This paper presents a new methodology for structuring the control architecture of cyber-physical systems with intelligent components: The Hierarchical Intelligent Component Architecture (HICA). Compared to traditional design methods, this methodology integrates the design of the physical and software architecture simultaneously. This paper also describes the model-driven engineering to realize this architecture using SysML diagrams to implement the code in IEC 61499 standard. Diagram Linkage Table (DTL) is the central element that allows the transition from SysML diagrams to IEC 61499.

Keywords: Model-based methods, Automobile, Autonomous vehicles
Abstract: With a rapid increase in the vehicular industry to ensure maximum efficiency and lower fuel consumption in the vehicles, advanced control strategies are required. Such strategies need precise information of intake manifold pressure, engine speed, and fuel flow rate. Due to the engine placement and operation, sensors can not be placed to measure all the variables. This issue is addressed in this paper and a new adaptive Unscented Kalman filter (UKF) is proposed to estimate these variables. The novelty lies in the new adaptive laws that are designed to update the process noise and measurement noise covariances within the constrained augmented state-based UKF (CASUKF). Another contribution lies in the new combination of the novel adaptive laws, and CASUKF. In the literature, variants of the UKF either adapt the process noise and measurement noise covariances on the standard UKF or implement CASUKF with constant values of the process noise and measurement noise covariances. The algorithm is implemented for the nonlinear mean value spark-ignition engine model. Simulation results are shown to provide the effectiveness of the algorithm in comparison to other variants of the UKF

Keywords: Autonomous vehicles, Model-based methods, Transportation systems
Abstract: The wheel odometry can be applied to expand the state estimation performance of an autonomous vehicle, since this type of motion estimation is robust in the cases when the generally utilized GNSS and IMU-based methods fail, e.g. near high-rise buildings or in low-speed maneuvering. This type of odometry is cost-effective as well, but the estimation accuracy is limited by the parameter uncertainty. Due to the nonlinear behavior and the noises, the calibration with high precision remains an open question in the context of autonomous vehicles. This paper proposes an identification method that applies batch mode of the nonlinear least squares fitting to mitigate the impact of noises. The method is validated through vehicle test experiments which demonstrate that the bias in the parameter identification is reduced, and the calibrated wheel odometry can be utilized in the state estimation layer of an autonomous vehicle.

Keywords: Fault detection and isolation, Model-based methods, Automobile
Abstract: Failures caused by load cycling significantly limit the reliability and durability of proton exchange membrane fuel cells (PEMFC) in vehicular applications. Improper management of load cycling accelerates cell degradation and can lead to severe material attenuation. Integrating an effective fault diagnosis system for early fault detection is key to maintain high cell performance. This paper considers the failure events of flooding and catalytic degradation due to their significant impact on cell lifetime. The square root unscented kalman filter (SRUKF) is adopted to provide optimal state estimates based on a semi-empirical model of a PEMFC. Then posteriori probabilities of flooding and catalytic degradation are calculated based on the Bayes' Rule and used as fault indication signals. Based on these signals, a decision logic is derived. Simulation results demonstrate that the proposed strategy successfully achieves the objective of early fault detection and isolation.

Keywords: Model-based methods, Chemical processes, Mechatronic and robotics
Abstract: This paper proposes a novel controller synthesis for industrial systems with time delays. The aim of this control strategy is to extend the well known RST controller design to systems with dead-time. The main advantage of this technique is to propose a simple design of the controller with one tuning parameter. The proposed controller uses the Smith predictor in addition to the the RST controller. This solution can be used for stable, unstable and integrating systems. The proposed controller is implemented into a Schneider PLC for a field test.