Force Feedback Design of Operation Levers Considering the Characteristics of Human Force Perception to Improve Hydraulic Excavator Operability

Appropriate reaction force design is essential to improve the lever operability of a hydraulic excavator that is difficult to operate. However, the force characteristics a human perceives when operating these levers are unknown. It is unclear whether the reaction force characteristics of the conventional lever are optimum for humans. Thus, this study aims to clarify the perceived force characteristics during the lever operation and verify the effectiveness of the lever reaction force design. In this study, a perceived force prediction method was proposed based on a musculoskeletal simulation for the lever operation. Also, it was confirmed that the perceived force could be estimated within a 7.8%-14.3% root mean square error. Furthermore, we developed the lever with the reaction force characteristics in which the perceived force varied linearly with the lever angle and confirmed that the proposed lever significantly improved operability when performing the leveling task with the excavator.