H 2 Performance Analysis of Tractors Traveling on Rough Terrain

The automation of tractors has become increasingly important in recent years. The challenge in automating tractors is to achieve their stable traveling on rough terrain. The unstable behavior of tractors reduces working efficiency, which worsens productivity; additionally, safety concerns arise. Thus, this study aims to investigate the effects of the road surfaces on the behavior of tractors traveling on rough terrain for achieving their stable traveling. We quantify the magnitude of the body vibration of tractors using the H2 norm and theoretically analyze the H2 norm of a system corresponding to a tractor traveling on rough terrain. To improve the accuracy of the analysis, we modify the system by focusing on the relationship between the H2 norm, white noise, and the characteristics of the road surface. We derive the H2 norm of the modified system as a function described using the characteristics of the tractor and road surface. Numerical examples demonstrate that the analysis result based on the modified system accurately captures the behavior of the tractor compared with the result based on the original system. The results in this study clarify the relationship between the magnitude of the body vibration of tractors and the roughness of road surfaces, which helps to achieve the stable traveling on rough terrain.