World Health Organization (WHO) has declared COVID-19 a pandemic on March 11, 2020. As of May 23, 2020, according to WHO, there are 213 countries, areas or territories with COVID-19 positive cases. To effectively address this situation, it is imperative to have a clear understanding of the COVID-19 transmission dynamics and to concoct efficient control measures to mitigate/contain the spread. In this work, the COVID-19 dynamics is modelled using susceptible-exposed-infectious-removed model with a nonlinear incidence rate. In order to control the transmission, the coefficient of nonlinear incidence function is adopted as the Governmental control input. To adequately understand the COVID-19 dynamics, bifurcation analysis is performed and the effect of varying reproduction number on the COVID-19 transmission is studied. The inadequacy of an open-loop approach in controlling the disease spread is validated via numerical simulations and a robust closed-loop control methodology using sliding mode control is also presented. The proposed SMC strategy could bring the basic reproduction number closer to 1 from an initial value of 2.5, thus limiting the exposed and infected individuals to a controllable threshold value. The model and the proposed

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This paper presents a string stable controller for the autonomous operation of a platoon of Heavy Commercial Road Vehicles (HCRVs) in a connected environment. This study considers factors such as brake/powertrain actuator dynamics, resistive forces, tyre model and wheel dynamics, which are crucial during on-road operation of HCRVs. A nonlinear vehicle dynamic model encompassing all these factors has been considered. The dependency between aerodynamic drag and inter-vehicular distance in the platoon has also been taken into account. The aforementioned factors motivated the use of Sliding Mode Control (SMC), which is a nonlinear and robust control technique. A lower level Proportional Integral Derivative (PID) controller has been successfully integrated with SMC to compensate for pneumatic brake and powertrain system delay. The designed controller was evaluated for string stable platoon operation by considering various road conditions, load conditions and operating speeds. It was observed that the string stable controller performance is highly dependent on the operating conditions. To ensure string stable operation for different operating scenarios, an adaptive time-headway based enhancement has also been integrated in the controller design. The efficacy of the proposed adaptive time-headway policy over the existing constant time-headway policy has been methodically analysed and a performance comparison between them has also been presented. The aspect of communication delay during connected vehicular operation has also been studied and the maximum tolerable communication delay magnitude for maintaining string stable operation has also been presented.

Integration of heavy commercial road vehicle platooning concept and electric vehicle technology is a promising approach as far as sustainable freight transportation is considered. This article attempts to design a string stable controller for an electric heavy commercial road vehicle platoon by incorporating critical factors such as complete vehicle dynamics model, pneumatic brake system model and cooperative braking between friction and regenerative braking systems. The sliding mode control technique has been used for string stable platoon operation. The impact of various battery pack locations on string stability has also been analysed. The performance of the controller has been investigated by considering electric heavy commercial road vehicle platoon operation on different road slope (straight, uphill and downhill) conditions, dry and wet road conditions and vehicle load conditions. It has been observed that the battery pack location has a significant influence on string stability with respect to the platoon operating conditions. During operation on straight and level roads, string stability was achieved irrespective of the location of the battery pack. However, during downhill and uphill driving conditions, it was found that placing the battery pack near front and rear axle locations, respectively, helped in ensuring string stable platoon operation.

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