Combining energy and power based safety metrics in controller design for domestic robots

This paper presents a general passivity based interaction controller design approach that utilizes a combined energy and power based safety norms to assert safety of domestic robots. Since these robots are expected to co-habit the same environment with a human user, analysing and ensuring their safety is an important requirement. Safety analysis of domestic robots determine whether a robot achieves a desired safety level according to some quantitative safety metrics. When it comes to controller design for human friendly robots, it often involves introducing compliance and ensuring asymptotic stability using impedance control technique and passivity theories. The controller proposed in this work uses a passive design that extends the standard impedance control scheme with energy and power based safety metrics to ensure that safety requirements defined in these norms are achieved by domestic robots. The effectiveness of the proposed guideline is illustrated with simulation and experimental results.