Loose rock detection methods for automating the scaling process

For the scaling process to be successful, it is important to first detect the loose rock. Even today, this task is mainly performed by experienced personnel. This leads to opportunities for increased potential to use sensor driven digital assistance systems. This paper presents a review and analysis of sensor-based loose rock detection methods considering the specific conditions of testing and use. The investigations can be classified into three categories based on their respective sensor technology approach. The opportunities for automating the scaling process highly depend on the method used. If scaling is conducted manually, the pre-entry examination could be automated. For the automation of the entire process, the use of machinery is more beneficial. Long wave infrared (LWIR) cameras or visual techniques have a great potential. However, in the case of LWIR, innovative methods for generating a sufficient heat flow between air and rock need to be developed in future.