Tham khảo tài liệu 'machine learning and robot perception - bruno apolloni et al (eds) part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 144 M. J. L. Boada et al. born they undergo a development process where they are able to perform more complex skills through the combination skills which have been learned. According to these ideas the robot has to learn independently to maintain the object in the image center and to turn towards the base to align the body with the vision system and finally to execute the approaching skill coordinating the learned skills. The complex skill is formed by a combination of the following skills Watching Object Center and Robot Orientation see Fig. . This skill is generated by the data flow method. activate par aiiis de act ivate Fig. . Visual Approaching skill structure Watching a target means keeping the eyes on it. The inputs that the Watching skill receives are the object center coordinates in the image plane and the performed outputs are the pan tilt velocities. The information is not obtained from the camera sensor directly but it is obtained by the skill called Object Center. Object center means searching for an object on the image previously defined. The input is the image recorded with the 4 Reinforcement Learning in an Autonomous Mobile Robot 145 camera and the output is the object center position on the image in pixels. If the object is not found this skill sends the event OBJECT-NOT FOUND. Object Center skill is perceptive because it does not produce any action upon the actuators but it only interprets the information obtained from the sensors. When the object is centered on the image the skill Watching sends notification of the event OBJECT CENTERED. Orientating the robot means turning the robot s body to align it with the vision system. The turret is mounted on the robot so the angle formed by the robot body and the turret coincides with the turret angle. The input to the Orientation skill is the turret pan angle and the output is the robot angular velocity. The information about the angle is obtained from the encoder sensor placed on the pan tilt .