Observer design for Lur'e systems with multivalued mappings: a passivity approach

This paper considers the design of state observers for Lur’e systems with multivalued mappingsin the feedback path. In particular, we focus on maximal monotone mappings that that do notrequire any compactness and local boundedness properties and include various models for relays,friction characteristics and complementarity conditions. We propose two types of observers that areconstructed by rendering a suitable operator passive in an appropriate sense. The well-posednessproperties of the observer dynamics are carefully analyzed and the global asymptotic stability of theobservation error is formally proven.