Effects of Load Information Feedback Considering Class Differences on Machine Switching in Teleoperated Hydraulic Excavators

The construction industry currently is confronted with significant challenges, stemming from a decreasing working population coupled with an aging workforce. Accordingly, the development of teleoperated hydraulic excavators is being investigated to optimize operations. The ability to switch between multiple machines during operations is expected to reduce transportation and labor costs, thereby increasing productivity. However, work efficiency may be severely affected when operators switch between different classes of machines, such as excavators with varying sizes and capabilities. Each machine class operates differently, and immediate adjustments to the dynamic characteristics may be challenging. Previous research has demonstrated that operators of teleoperated hydraulic excavators struggle to perceive load, as they rely on visual information from cameras instead of tactile feedback. Consequently, loading information, particularly related to the attachment's maximum exertion force, is difficult to estimate. This study proposes a load index called "attachment joint-load ratio" to mitigate decreased work efficiency when switching machines. This index considers the attachment's maximum exertion force and attempts to provide operators with intuitive feedback about load conditions. This study focuses on excavation work and compares the operating characteristics of a standard hydraulic excavator with a conventional load feedback method. The objective is to ascertain whether feedback regarding the attachment joint load ratio can mitigate the effects of transitioning between machine classes on work efficiency. Using a simulator that mimics a teleoperated hydraulic excavator based on the proposed feedback method, we conducted experiments and verified the effectiveness of the proposed method.