OP-MR: the implementation of order picking based on mixed reality in a smart warehouse

This paper presents a mixed-reality (MR) application called order picking with mixed reality (OP-MR) for the order-picking activities in a smart warehouse. OP-MR is a set of applications operated by an administrator through a computer server and by the staff using the HoloLens MR device. OP-MR is built to reduce the operational time of an order-picking activity by providing the shortest route to the staff. The HoloLens device displays the order-picking instructions through the MR window, renders virtual navigation, and virtually marks the positions of items. For determining the shortest distance for an order picking, the proposed OP-MR method combines two different algorithms, namely the Held–Karp algorithm in the server and A* algorithm in the client. The Held–Karp algorithm sorts the items in the pick-up list based on the nearest position. Next, the A* algorithm determines the shortest route to ensure that a user travels the shortest distance to pick all the items. To show the effectiveness of the proposed OP-MR method, OP-MR is implemented and experiments are performed. The experimental results show that OP-MR outperforms paper-based order-picking from the viewpoint of completing all the order picking.