Usability assessment of compaction operator support systems using virtual prototyping

The successful adoption of Hot Mix Asphalt (HMA) compaction Operator Support Systems (OSSs), which use sensory information to help operators improve the safety and productivity of their operations, is heavily dependent on the usability of the systems. However, there is a major dilemma in the design and development of compaction OSSs. On one hand, providing raw sensory data (i.e., temperature and compaction count) to the operator in a descriptive manner, can cognitively overloading the operators, i.e., infobesity problem. On the other hand, the over-processed data, which can be presented to the operators as prescriptive compaction guidance, e.g., a compaction trajectory, may give operators the sense of losing control of the operation and de-professionalization of their trade. Therefore, there is an ongoing debate over the best strategy for the design and development of compaction OSSs. To put this usability aspect at the heart of the design and development strategy of compaction OSS, first, it is essential to systematically assess various OSS alternatives from the usability perspective. However, the conventional approach of usability testing, which relies on the use of physical prototypes, can be time-consuming and logistically difficult to execute. To address this issue, this research proposes and implements a Virtual Prototyping (VP) approach to analyze the usability of different compaction OSSs. In this approach, a Virtual Reality (VR) compaction simulator is developed and utilized to present 3 different alternatives for compaction OSS, which varies in the level of support they provide and receive feedback from the end-users. The results show that from the user perspective, semi-guidance compaction OSSs, which present the compaction priority, are preferred over both descriptive and prescriptive systems. The users tend to perceive this level of support as a middle ground solution that offers them a means for real-time strategy (re-)development without compromising their control of the process. It is also demonstrated that the VR simulator has the potential to serve as a powerful technology assessment platform that allows end-users to have an open and substantive dialogue about the system with researchers and machine designers.