Visualization of comprehensive work tendency using end-point frequency map for human-operated work machines

This paper proposes a framework for visualizing comprehensive work tendency using a frequency plot map of the end-point of a manipulator as a fundamental study of work analysis using long-term data for human-operated work machines. A visualization system requires high generality and commonality to enable to extract various characteristics to be extracted on an arbitrary time scale independently of the work machine specifications, work contents and environment, and machine operator. The proposed framework meets this requirement by first creating a two-dimensional end-point plot map with its origin fixed at the yaw joint of the manipulator to deal with arbitrary usage conditions. It then extracts arbitrary characteristics by using hierarchical feature extraction filters, including binary, quantity, and advanced filters, defined by three kinds of essential data: operation, movement, and load. Finally, it quantifies the filtered map by gridding and normalization to visually grasp its frequency distribution. Two experiments in which the work environments and completion time differed were conducted using an instrumented hydraulic arm. Results indicated that the comprehensive work tendency revealed by using the proposed framework corresponds to the actual work results independently of the various conditions.