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This article investigates sampled-data vehicular platoon control with communication delay. A new sampled-data control method is established, in which the effect of the communication delay is involved. First, a linearized vehicle longitudinal dynamic model is obtained using the exact feedback-linearization technique. Then, under the leader-predecessor following communication strategy, considering communication delay, a platoon control law is proposed based on sampled state information, which allows the weights of state errors to vary along the platoon. Complemented by additional string stability conditions, a useful string-stable platoon controller design algorithm is proposed. Finally, the effectiveness of platoon controller design methodology is demonstrated by numerical examples.

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The use of self-consolidating concrete and advanced pumping system enables efficient construction of super high-rise buildings; however, risks such as clogging or even bursting of pipeline still exist. To better understand the fresh concrete pumping mechanisms in detail, the discrete element method is employed in this paper for the numerical simulation of local pumping problems. By modeling the coarse aggregates as rigid clumps and appropriately defining the contact models, the concrete flow in representative pipeline units is well revealed. Important factors related to the pipe geometry, aggregate geometry and pumping condition were considered during a series of parametric studies. Based on the simulation results, their impact on the local pumping performance is summarized. The present work demonstrates that the discrete element simulation offers a useful way to evaluate the influence of various parameters on the pumpability of fresh concrete.