Soil/multibody interaction simulation tool

The French National Research Institute for Agriculture, Food and the Environment (INRAE) is a public research institute. It is the world's leading research organisation specialising in agriculture, food and the environment. In the face of population growth, climate change, resource scarcity and declining biodiversity, INRAE develops solutions for multifunctional agriculture, quality food and sustainable resource management.

Based in Clermont-Ferrand (Aubière), the TSCF (Technologies and Information Systems for Agrosystems) research unit carries out research in the field of agri-environmental systems engineering, including agricultural robotics, which is seen as a solution to ensure sufficient agricultural production while respecting the environment and relieving farmers of difficult and risky tasks.

Soil compaction is a major environmental problem caused by the circulation of heavy machinery. The goal of the Soil-FriendBot project is to propose mobility solutions based on reconfigurable robotics with reduced soil impact on the soil. In order to compare different solutions for the design and control of mobile platforms from the point of view of their impact on the soil, a simulation/co-simulation tool is needed that can simulate both the mechanical behavior of the soil and the dynamics of multi-body systems (the mobile robot). This tool must be able to model and quantify the changes in the mechanical properties of the soil due to the passage of the robot, and thus quantify its impact in terms of soil compaction and shear.

Deformable soil modeling is a key issue in the selection of design parameters for off-road machines, tires and agricultural implements. In the past, empirical, semi-empirical and analytical models were used to model the soil. Then numerical models based on the Finite Element Method (FEM) appeared and proved their effectiveness in modeling wheel-soil interaction. More recently, models based on granular modeling of the soil (approaches that model the soil as a continuous or discrete granular medium) have made it possible to model wheel/soil and tool/soil interaction. Based on these different approaches to soil modeling, commercial (EDEM by Altaïr, LS-DYNA by ANSYS, ABAQUS, etc.) and open source (PFC3D, Chrono, etc.) simulation tools have been developed and implemented in research and industrial projects.

Internship Tasks

The work to be done during the internship will be the following:

1- Make an inventory of soil simulation tools, classifying them according to their theoretical approach to soil modeling and their limitations/fields of application. Select and test open source soil simulators for typical applications (rigid body/soil interaction).

2- Identify open source soil simulators and simulators presented in scientific articles that are suitable for use in co-simulation with available multi-body simulation tools (examples: MSC Adams, Mathlab/Simulink, open source simulators). Check the possibility of co-simulation on simple examples.

3- Select the most suitable simulation tools for co-simulating a soil-multi-body system and use them to implement a wheeled robot with active suspension moving on a deformable soil.

Final year engineering student or M2 with a background in mechanics, robotics or computer science. Interested in software for simulation of physical systems.