Versatile and robust systems able to respond sensibly to challenges not precisely specified in their design, as envisaged in Challenge 2 target outcome (a), depend on (amongst other competences) effective perception systems able to function in complex and variable conditions. The principal objective of the proposed project is to discover how to engineer such systems, specifically embodied active sonar perception systems which can serve as a complement to vision and facilitate the deployment of robotic systems in situations where vision is infeasible.For understanding the implementation of sonar systems able to function in demanding and open-ended environments, the Chiroptera (bats) are an obvious source of ideas. Their astounding diversity of diet and habitat attests to their success in integrating morphological, acoustic and behavioural parameters to enable robust and versatile hunting behaviours --- the bat equivalent of tangible object handling.The project will implement and evaluate two demonstration sensors built as biomimetic models of an insect gleaning and a water-trawling bat species respectively. It will use a classic biomimetic methodology, involving close collaboration between bat ethologists and roboticists. It will proceed by identifying and measuring the relevant acoustic and morphological parameters of a few carefully selected bat species, reconstructing from that the bat's acousticexperience as it flies through natural hunting tasks. From this data, computational models of how the bat coordinates its acoustic, behavioural and morphological choices during hunting will be elicited and implemented on appropriate robotic systems. The robustness, versatility and generality of these implemented models will be evaluated from an engineering standpoint as example embodied activesonar perception systems, using tasks analogous to the hunting tasks of their living prototypes; evaluation from a biological standpoint will also be carried out.