Evaluating the Mechanical Redesign of a Biped Walking Robot Using Experimental Modal Analysis

Structural dynamics can have a significant influence on the performance of robots. This has already been extensively shown for robot manipulators. In a previous work, we have also shown this for our biped walking robot Lola. Vibration issues caused by the mechanical structure of Lola are visible in the joint controllers and are limiting the performance of her walking and balancing controllers. We showed this by measuring the open-loop transfer functions of these controllers and linking the dynamics of the control plant to the structural dynamics of Lola by comparing the results to an Experimental Modal Analysis. The knowledge gained from this analysis influenced the redesign of Lola’s upper-body structure. In this work, we will show the benefits gained from the new mechanical design by performing and comparing the same tests as done in our previous work.