Mechanics Modeling and Simulation Analysis of a Novel Articulated Chassis for Forestry

When the power chassis of general forest machinery is working on uneven terrains, the power is insufficient due to the poor traction between the wheels and the road surface, which affects the driving operation of the entire vehicle. According to the principle of multiple-degree-of-freedom profiling, a novel articulated chassis for forestry was designed. The innovative articulated structure realizes active pitching, active deflection, and passive torsion in the front and rear frames. The kinematics and dynamics (mechanics modeling) of the articulated structure were analyzed, and a theoretical model of the relationship between the rotation angle of the rotary shaft and the pitching angle of the front and rear frames was established. A three-dimensional model of the forestry chassis was established using SolidWorks, and a kinematic simulation of the articulated structure was performed by ADAMS. When the simulation and theoretical results were compared, the maximum error was found to occur at the position where the rotation angle of the rotary shaft was 90° and was less than 1%, demonstrating the accuracy of the theoretical model. Furthermore, a chassis working condition simulation experiment was conducted using ADAMS. When climbing a slope with a wheel speed of 1.39 rev/s, the duration of the effective driving force of the front wheels of the novel chassis was 61.5% longer than the ordinary chassis. In steep-convex-obstacle climbing, the active pitch function of the novel chassis can ensure that the wheels have a good contact with the road, and the load can pass through an obstacle smoothly. For single-side obstacle crossing, the wheels of the novel chassis can provide a continuous and stable effective driving force for obstacle crossing owing to the excellent road surface profiling.