Constructing automatic work analysis system for order picking process

Abstract

Work analysis is one of critical tools for improving order picking efficiency in logistics centers. Traditionally, video analysis has been used to analyze work time for various tasks. However, video analysis generally requires a substantial amount of time and labor, which makes it too inefficient for real-time work improvement. To address this, a novel automatic work analysis method is proposed for analyzing the order picking process in logistics centers in this study. The automatic work analysis method can be divided into two parts: dynamic positioning and motion analysis. With the proposed method, an ultrasonic network and a tracking camera are used for measuring a worker's real-time position while he/she is moving, and an acceleration sensor is used for checking the acceleration of the dominant working hand. Using the position and acceleration data, the worker's motion is then estimated by an estimation model pre-tested for accuracy. To test the effectiveness of the proposed method, an experiment was conducted in which the measurement error of positioning was found to be approximately 0.01±0.19 m for the 𝑥-coordinate values and 0.03±0.45 m for the 𝑦-coordinate values. The total measurement error was confirmed to be within a one-step stride. The results of the motion analysis were more than 90% consistent with those obtained by traditional video analysis.