1,720,968 research outputs found
Non-linear Net Engine Torque Estimator for Internal Combustion Engine
No full textAn engine torque estimator, based on sliding mode technique, is proposed in this paper: a switching term, function of the error between the estimated and measured instantaneous engine speed is used to ensure the convergence of the estimation error. This approach provides robustness against the uncertainties of the model and the variations of the parameters during the life of the vehicle. The estimator is then tested with a DI Diesel engine simulator, calibrated with experimental data and realized by the authors. The estimator does not include the combustion process, and this feature make it suitable for any kind of internal combustion engine after a short calibration procedure
Distributed robust output consensus for linear multi-agent systems with input time-varying delays and parameter uncertainties
No full textThis study addresses the leader-tracking problem for linear multi-agent systems in the presence of both parameter model uncertainties and time-varying communication delays. To solve the robust output consensus problem, a delayed distributed proportional–integral–derivative control is proposed and the overall closed-loop stability is proven by exploiting the Lyapunov–Krasovskii theory. Delay-dependent robust stability conditions are given via linear matrix inequalities which allow the proper tuning of robust control gains. The effectiveness of the theoretical derivation is confirmed through a numerical analysis in the practical application domain of cooperative driving for connected vehicles
On the effectiveness of the extended cooperative adaptive control for vehicles platooning
No full text
Distributed Leader-Tracking for Autonomous Connected Vehicles in Presence of Input Time-Varying Delay
No full textIn this paper, the leader tracking problem for a platoon of connected vehicles in presence of homogeneous time-varying Vehicle-to-Vehicle communication delays is addressed. To this aim, the platoon is recast as a network of multiagent systems and consensus is achieved by leveraging a delayed distributed strategy that complements the standard linear diffusive control protocol with additional distributed integral and derivative actions. The asymptotic stability of the closed-loop delayed system is hence analytically proven by exploiting the Lyapunov-Krasovskii theory. Stability conditions are expressed as a set of Linear Matrix Inequalities, whose solution allows the proper tuning of proportional, derivative and integral gains such as to counteract the presence of the time-varying input delay. An exemplar tracking maneuver is considered for evaluating the performance of a connected vehicles fleet and the numerical results confirm the effectiveness of the theoretical derivatio
On the Experimental Validation of Adaptive MPC-based Path Tracking Controller in CCAM Environment
No full textThis paper investigates the practical implementation and real-time feasibility of an adaptive MPC-based path-tracking control system for Connected Autonomous Vehicle (CAV) in a smart Cooperative Connected Automated Mobility (CCAM) environment. The proposed path-tracking control architecture is designed according to the best practice of the Model-Based Design (MBD), where a PID control governs the CAV longitudinal behaviour while the adaptive MPC drives its lateral dynamics. According to the V-Cycle workflow development steps, the proposed control architecture is validated through Software-in-the-Loop (SiL) and Hardware-in-the-Loop (HiL) platforms. This latter involves the control hardware Nvidia Drive AGX Orin and Carla simulator. After disclosing the proper functioning of the control system in real-time over the target hardware, a real-world experimental campaign is performed on a real SUV-prototype vehicle moving in a City Area test site located in the Campania region, Italy. The proving ground is such that all the necessary equipment for the emulation of CCAM environment is available. Experimental results prove the real-time feasibility and efficiency of the proposed solution
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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