A hybrid approach to recognising activities of daily living from patterns of objects use

Abstract

Over the years the cost of providing assistance and support to the ever-increasing population of the elderly and the cognitively impaired has become an economic epidemic. Therefore, the emergence of Ambient Assisted Living (AAL) has become imperative, as it encourages independent and autonomous living by providing assistance to the end user by conducting activity and behaviour recognition. Accurate recognition of Activities of Daily Living (ADL) play an important role in providing assistance and support to the elderly and cognitively impaired. Current knowledge-driven and ontology-based techniques model object concepts from assumptions and everyday common knowledge of object used for routine activities. Modelling activities from such information can lead to incorrect recognition of particular routine activities resulting in possible failure to detect abnormal activity trends. In cases, where such prior knowledge are not available, such techniques become virtually unemployable. A significant step in the recognition of activities is the accurate discovery of the object usage for specific routine activities. This thesis presents a hybrid approach for automatic consumption of sensor data and associating object usage to routine activities using Latent Dirichlet Allocation (LDA) topic modelling. This process enables the recognition of simple activities of daily living from object usage and interactions in the home environment. In relation to this, the work in this thesis addresses the problem of discovering object usage as events and contexts describing specific routine activities, especially where they have not been predefined. The main contribution is the development of a hybrid knowledge-driven activity recognition approach which acquires the knowledge of object usage through activity-object use discovery for the accurate specification of activities and object concepts. The evaluation of the proposed approach on the Kasteren and Ordonez datasets show that it yields better results compared to existing techniques.