Information Visualization Using Transparent Displays in Mobile Cranes and Excavators

Abstract: Operating heavy machinery, such as mobile cranes and excavators, is a complex task. While driving the machine, operators are also performing industrial tasks, e.g. lifting or digging, monitoring the machine’s status, and observing the surroundings. Modern heavy machinery is increasingly equipped with information systems that present supportive information to operators, so that they could perform their work safely and productively. Supportive information in heavy machinery is generally presented visually using head-down displays, which are placed in lower positions inside the cabin in order to avoid obstructing operators’ view. However, this placement makes visual information presented using head-down displays tend to be overlooked by operators, as the information is presented outside their field of view.This dissertation investigates the possible use of transparent mediums for presenting visual information on the windshield of mobile cranes and excavators. By presenting information on the windshield, operators are expected to acquire visual information without diverting their attention away from the operational area. The design process includes (1) observing heavy machinery operators in natural settings through available videos on the Internet, (2) conducting an empirical study on the impact of different information placements, (3) reviewing the state of the art of display technologies that could be used to visualize information around the windshield of heavy machinery, (4) reviewing relevant safety guidelines to determine what kinds of critical information that operators should know, (5) conducting design workshops to generate visualization designs that represent critical information in operations of mobile cranes and excavators, (6) involving professional operators to evaluate and improve the proposed visualization designs, and (7) developing a functioning transparent display prototype that visualizes one kind of critical information that professional operators considered as the most important one.The main finding from the observation using online videos suggested that heavy machinery operators spent considerable amount of time looking through the front windshield, and thus the front windshield could be used as a potential space for presenting visual information. The main finding of the empirical study also indicated that presenting information closer to the line of sight produced higher information acquisition and lower workload, compared to when information was presented farther from the line of sight. Based on the evaluation with professional operators, there seemed to be a good match between the proposed visualization designs and the operators' way of thinking, since the operators were able to understand and use the proposed visualization designs with little explanations. On the basis of the three most important findings above, there is a strong indication that placing the developed transparent display on the front windscreen of heavy machinery would make it easier for operators to perceive and process the presented information.