Study on Relationship between Traveling State and Chassis Strain at Traveling Loose Soil for Rovers

The surface of the moon and planets have been covered with loose soil, and there is a risk that the wheels may stack, so it is necessary for the rover to recognize the traveling state. However, in such environments as nighttime and dark spaces, the visibility of the rover is degraded by the camera based method, and a new system for recognizing the traveling state is required. As a new method for recognizing the driving state, we focused on the intrinsic sensation of the human body and aimed to develop a system that recognizes the travelling state from the shape deformation of legs. In this study, we experimentally verified the relationship between the change in strain, which is the amount of deformation acting on the, and the traveling state when the wheel travels. From the experimental results, we confirmed that the strain in the leg was displaced and that the strain changed oscillatory when the wheel was traveling. In addition, based on the function of muscle spindles as mechanoreceptors, we discussed two methods of analyzing the strain change: nuclear chain fiber analysis and nuclear bag fiber analysis. From these analysis methods, we detected changes in the force applied to the wheels and the movement of the ground during traveling from the strain. Therefore, the change of the traveling state could be detected by the strain, and it was confirmed that the traveling state could be detected.