Development of a variable ground pressure tracked chassis for soil compaction mitigation

Traditional tracked agricultural machinery with a fixed contact geometry struggles to balance high maneuverability on hard pavements and low soil compaction in soft paddies. To solve this problem, this paper proposes an active variable ground pressure tracked chassis system. The effective ground contact length of the track is adjusted by distributed electric cylinders and a multi-stage linkage mechanism. To evaluate its performance, we conducted kinematic modeling, finite element analysis (FEA), and field tests. First, a planar kinematic model was established to describe the relationship between the cylinder stroke and the track geometry. Second, an internal load transfer path method was used in the FEA post-processing to reduce numerical errors from the track lugs, showing that the low-pressure mode reduces the mean compressive stress from 0.03 MPa to 0.008 MPa. Finally, soil bin tests with a physical prototype were carried out. The results indicate that the low-pressure mode decreases the peak subsoil stress from 93 kPa to 63 kPa at low speeds. In contrast, the regular mode with a shorter track length on hard surfaces reduces steering resistance. This study provides a practical design method for adaptable agricultural tracked vehicles.