Modeling of ADLs in its Environment for Cognitive Assistance

1. Modeling of ADLs in its Environment for Cognitive Assistance Jérémy Bauchet and André Mayers

2. Introduction • Cognitive assistance, in smart homes, aims at supporting occupants for the completion of their activities of daily living (ADLs)

3. Introduction (2) • Implies for the system a prior knowledge about the occupant • its activities • its environment • This knowledge is necessary for : • activity recognition, as a prior step of cognitive assistance in smart homes • finally, for cognitive assistance

4. Plan • Introduction • A model for the description of ADLs • a hierarchical approach • the environment of completion • Taking into account the specific behavior of the occupant • Implementation of the models • Results and perspectives concerning activity recognition and cognitive assistance • Conclusion

5. A hierarchical model for ADLs description • Two type of nodes : tasks and methods • a task : a goal • a method : a way to realize the task → a set of subtasks → and rules of integration of subtasks : • partial or total sequence • repetition or necessity constraint

6. A hierarchical model for ADLs description (2) • Roots are abstract tasks (ADLs, IADLs) • Leaves are methods of terminal tasks = an atomic way to realise a concrete goal • Tasks can be common to several methods → if common nodes are duplicate, this model is a tree

7. Model of activity

8. A model of ADLsin its environment • Environment of activity completion • Includes all actors of activity completion • daily living objects • furniture • the occupant, as the actor of his own task completion → e.g. : her/his current position

9. Description of the environmentof completion • Static description : • Actors : fridge • Events concerning actors fridge : door opened, door closed • Dynamic description : Assertions, giving current value of several pieces of information concerning actors • <fridge, door, opened> • <occupant, position, kitchen>

10. Links between activities andthe environment • Events concerning actors in the environment are associated with terminal methods • events are a consequence of the concrete actions of the occupant • events can be observed via distributed sensors • occurrence of events are used for activity recognition

11. Links between activities andthe environment (2) • Tasks and method are considered as operators of a planning domain • they have preconditions and effects • both concern the environment

13. Taking into account the specific behavior of the occupant • The activity model is a support for the generic description of ADLs and IADLs → We need an occupant model to describe his/her specific comportment

14. An episodic memory for the occupant model • Allows to precise how one occupant usually completes an activity • the method used for a given task • the time slot of completion • the location • the sequence of subtasks

15. Implementation • XML • library of tasks and methods (activity model) • description of the environment • episodic memory persistence • SVG • graphical representation of the environment • Java • XML parsing • internal representation of the models and treatments • SVG management

16. Results and perspectives : Concerning activity recognition • Goal : to compute the probability of completion of (I)ADLs given inputs • Inputs are : • description of ADLs • events • current time • knowledge about the occupant habits of life, given by the episodic memory

17. Activity recognition

18. Results and perspectives (3) :Concerning cognitive assistance • Description of activities, for step by step or global assistance • Preconditions → what has to be done before, where the activity can take place • Rules of integration for subtasks → how to complete correctly the activity • Episodic memory → anticipation process

19. Conclusion