This paper describes the advantages and the main functionalities of the robot companion and data-processing architecture in the QuoVADis project. This project targets the people reached of cognitive troubles with the objective of their assistance at home. The robot is involved in the service which ensures the safety of the patient and plays a part in the cognitive stimulation. The stimulation of the residual cognitive capacities consists in helping the patient to locate himself in time and space, by making him safe in the event of wandering, of confusion and anguish, and by facilitating his communication with the ambient environment. The safety of the patient is based on a telecare system in the residence which aims to allow dependent or weakened people to remain at home and to be helped or “medicalized” remotely in a more reactive way in the event of emergency. The main originality of the QuoVADis project resides in the combination of a robot with a cognitive stimulation system and an integrated telecare system. The robot brings its mobility and multi-modal (audiovisual, tactile) interaction capabilities for improving the quality of the services given by these two systems.