WHY OFF-THE-SHELF PHYSICS SIMULATORS FAIL IN EVALUATING FEEDBACK CONTROLLER PERFORMANCE - A CASE STUDY FOR QUADRUPEDAL ROBOTS

Simulators are essential to robotics research since they help us to understand physical properties of the robotic system as well as test control and motion planning approaches in a quick and safe manner.Yet most robotics simulators rely entirely on physics engines and do not model actuator dynamics, noise or delay.However, as we demonstrate in this work, modeling these effects is essential when evaluating the performance of closed loop controllers.In fact, neglecting them is one reason why controllers do not transfer well from simulation to hardware.While the presented study applies to most multi-link robots, our parameter choice is inspired by state-of-the-art quadrupedal robots.