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When facing the problem of modern logistics distribution under the large-scale network, the reasonable delivery task allocation has become an important part. For this problem, this paper uses the idea of decentralized control to establish a region division model in logistics distribution and transforms it into the multiple traveling salesmen problem with constraints of the road network and task allocation. The optimization goal of the model is to minimize the sum of the distances for logistics transport agents traveling all demand points in the system, with the constraints on the equilibrium of commodity requirements in each sub region. Then, a two-stage algorithm is proposed to solve the model. In the first stage, the K-means clustering method is used to obtain a highly feasible initial solution; In the second stage, the initial solution is optimized by the algorithm which is combining swap algorithm and tabu search algorithm. In the two-stage solution evaluation, the TSP solution based on the Lin-Kernighan algorithm is applied to obtain the sets of demand points with ranking of the route and the corresponding shortest distances for each divided sub region. Finally, to verify the effectiveness of the proposed model and solving method, two cases are presented in this paper. The region division method in logistics distribution proposed in this paper not only helps to reduce the total distance, but also helps to balance the workload of the logistics transport agents, thereby making great potential to reduce logistics costs and improving the overall operational efficiency of logistics distribution.

This paper describes an improved modeling and simulation analysis of a variable-length reel take-up system for hose retrieval/deployment during aerial refueling. Based on a previously developed finite segment model, full reel acceleration is applied to the first rigid link connected to the towing point. The variation in the length of the hose and its rate of change are distributed evenly across all of the hose segments through a re-discretization technique, and the dynamics of the hose’s motion are regarded as a series of quasi-static processes. First, numerical simulations of the steady-state trailing hose are compared with previous results and flight data. The non-linear dynamics of a variable-length hose–drogue system during aerial refueling are then analyzed under various retrieval/deployment conditions. The results indicate that the finite segment model is prone to inducing chain-link oscillations in the hose dynamics, which are not appropriate for such a flexible body. In two application cases, the non-physical oscillations were well filtered using the proposed method, achieving a simultaneous combination of accuracy, stability, and robustness. Several advantages of the simulated hose dynamics provide a theoretical basis and platform for subsequent research into control strategies for suppressing the hose whipping phenomenon during hook-up.

An improved reel take-up system for suppressing the aerial refueling hose whipping phenomenon (HWP) is proposed and analyzed. The conventional spring-loaded take-up system is improved by adding a rewinding acceleration changing rate limiter (RACRL), relying on a permanent magnet synchronous motor (PMSM). The effectiveness of this new reel take-up system is confirmed by the numerical simulation at various closure speeds. The results show that the new PMSM-RACRL reel take-up system successfully accomplishes the active control of tension oscillation and the suppressing of HWP with a straightforward strategy. The amplitude of tension oscillation is reduced to one-tenth of that without active control. It is also discovered that the reel take-up speed lagging behind the drogue closure speed is mainly caused by the oscillation of hose tension, and a maximum acceleration of the reel take-up system lower than the maximum closure acceleration of the drogue will inevitably cause the slack and whipping of the hose.