Real-Time environmental impedance estimation using a variable stiffness actuator as a variable stiffness sensor

This report describes the design and implementation of an estimation algorithm to estimate environmental impedance parameters, the stiffness and damping of a wall, using a variable stiffness actuator as a variable stiffness sensor. The estimation algorithm uses an observer, which is first shown to be stable with a bounded error, in combination with an extended kalman filter. The estimation algorithm is validated by both simulation and experimental results. Correct stiffness and damping estimates can be shown in the simulations but experiments on the real setup were unable to obtain correct damping estimates. Since the goal with respect to damping has not been accomplished, first a paper is presented which only treats the stiffness. The next chapters will introduce the damping to the system and will go into more detail.