Development and Validation of a Virtual Axle Model for Modern Agricultural Tractors

A modern tractor can be defined as a high-power, wheeled, or tracked agricultural vehicle that provides high tractive effort (or torque) at slow speeds, used for hauling, powering, and operating machinery in agriculture often equipped with GPS, automation, and advanced cabin technology. The key features that define a modern tractor are: Advanced Electronics and Automation, High-Efficiency Engines, Sophisticated Transmissions, Versatility and Operator Comfort and Connectivity/Data Management. In this scenario the front axle assumes an important role; it represents,with the tyre, the interface between the soil and the tractor’s transmission. It not only regulates the uniform transmission of driving torque to the ground, but also performs a primary filtering function with respect to the mechanical loads transmitted throughout the entire vehicle. This thesis work is carried out in collaboration with Carraro S.p.A. company, in the Research and Development department, a point of reference in the transmission sector and in the construction of agricultural vehicles. The internship activity made it possible to conduct an entire test, from the study of the sensor installation to the report writing, on an axle equipped with instrumented wheels in order to analyze the behavior of the saddle-beam front axle in different operating conditions, from static to dynamic. The goal of this work, in addition to what is written above, is to analyze sampled signals such as acceleration, moments, and forces, in order to create and validate the Adams Car model. A virtual model of the axle was developed in the simulation environment to perform a series of simulations and compare the obtained results with experimental data from the real system.