Validating multi-rigid body simulation of a wild robot

There exist few objective measures to evaluate or compare multi-rigid body dynamics simulations involving contact and friction. This absence creates uncertainty in simulation capabilities and accuracy, leaving users to wonder when can they trust simulations. Simulation science has focused on using theory and other simulations (verification) and real-world data (validation) to evaluate simulation correctness. With respect to rigid body dynamics, ballistic rigid body motion has been verified and validated, but rigid body simulations involving contact and friction are currently prone to producing results that appear inconsistent with real-world observations. Accurate validation is seldom performed for contacting “rigid” bodies, likely because the observation problem is so challenging (compared to, e.g., fluid dynamics, for which fluids are often transparent). This paper concentrates on a validation scenario for multi-rigid body dynamics with contact and friction, which are essential for simulating robotic locomotion and manipulation. We describe a collection and estimation process for telemetry data of a mechanically simple but highly dynamic, real-world robot whose motion is primarily driven by contact and friction, and we propose an approach for quantifying the performance of simulations of this robot.