Affordance-based indirect task communication for astronaut-robot cooperation

The problem with humanrobot task communication is that robots cannot understand complex human speech, whereas humans cannot efficiently use the fixed task request utterances required by robots. However, future planetary exploration missions will require astronauts on extravehicular activities to communicate task requests to robot assistants by using speech- and gesture-type user interfaces that can be easily embedded in their space suits. The solution proposed in this paper is indirect task communication based on the humanlike ability to utilize objectaction relationships in task communication. A conventional task communication method, in which the astronaut needs to communicate all the task parameters explicitly, is compared with communication methods where affordances, i.e., action possibilities, are used to complete the task communication. This comparison is done with three user experiments: one performed with a fully autonomous centauroid robot in a geological exploration work context and two with a simulated robot in a lander assembly work context. The experiments indicate that affordance-based indirect task communication methods can be used to decrease both the human workload and the task communication times in a planetary exploration type of work context, and that combined direct and indirect task communication methods seem to be preferable from a human point of view. (C) 2012 Wiley Periodicals, Inc.