This paper presents the developments with the SAM robot, established in the ARMEN project. We are interested in cognitive robotics. We have developed two complementary modules. The first one deals with the representation of knowledge, while the second develops the scenario generation. Indeed, the representation of knowledge tells us about the scene, the current state of the robot and the strategy to be adopted by the robot to achieve goals specified by an assisted person. The information extracted from the knowledge representation is the starting point to generate the action plan and the implementation of the scenario by the robot.