Between Input and Output: The Importance of Modelling Transients in Meal Preparation Tasks

We are moving closer to autonomous robots preparing meals. While restaurant robots in static environments already are successfully performing single actions like making pizza, the goal is to enablerobots to perform changing actions, in various environments and with any available object. Towards this goal, a methodology for creating actionable knowledge graphs that can be used to parameterise general action plans has been proposed. However, for extended failure handling towards fully automated action execution, we argue that transients need to be considered. A transient can be described as a transitory object in a task that is not the same as the input object anymore but not yet the output object of the task. For example, when pouring ingredients into a bowl to make the dough, the added ingredients form a mass of ingredients (here: a transient) that only becomes dough through mixing them. This work shows how transients can be modelled and how robots can integrate and possibly benefit from this modelling.