Toshimitsu Higashi

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We propose a control methodology of stacker cranes to avoid collisions in warehouse environment including the constraint on trajectories caused by dynamics. In a warehouse environment, there are three problems: constraint on trajectories caused by the consideration of dynamics (e.g., vibration control), safety in the case of an emergency stop, and practical(More)
We propose a method for reducing the computational time of motion planning for stacker cranes. Most automated storage/retrieval systems are only equipped with one stacker crane. However, this is logistically challenging, and higher work efficiency in warehouses, such as those using two stacker cranes, is required. In this paper, a warehouse with two stacker(More)
In this paper, fast heuristics for a centralized multi-agent route planner are presented and computationally evaluated. We solve a sub-problem of warehouse scheduling involving the routing of intelligent agents as a preliminary step in optimizing the total schedule. The problem involves the generation of routes for automated agents tasked with the transfer(More)
In this paper, the final stage of a multiphase approach for solving the picking problem in a warehouse is addressed. Given a number of agents, each with its own set of picking sequences (trips or routes) to accomplish, a dispatching problem is described and shown to have a non-polynomial search space with respect to the number of agents and number of(More)
The self-organization behavior of an extracellular polysaccharide (sacran) extracted from the cyanobacterium Aphanothece sacrum in response to lanthanoid ion adsorption was investigated. Consequently, cryogenic TEM images revealed that sacran could be cross-linked by Nd(3+) trivalent ions and formed a fibrous nanostructural network containing water.(More)
In a warehouse, efficient product transportation is required for high productivity. In general, it is recognized that mixed-load transportation can decrease the moving time to some extent. However, many scheduling methods without regard to mixed-load transportation have recently been proposed. In this respect, we propose a design for scheduling problems(More)
We propose control methodology of two stacker cranes to avoid collisions in an automated storage/retrieval system including the constraint on trajectories caused by dynamics as shown in Fig. 1. In the automated storage/retrieval system environment, there are three problems: constraint on trajectories caused by dynamics (e.g., vibration control), safety in(More)
Logistics network design problems are usually solved through experimental and intuitional approaches. These approaches are taken because of the complicated conditions that accompany problems associated with layout planning, stock analysis, network flow. In this study, the problem is divided into two parts: material flow and layout planning. An algorithm is(More)