Decision making for obstacle avoidance in autonomous mobile robots by time to contact and optical flow

Vision is a vital cue for human navigation, and it has become in a powerful tool for robot navigation. Computer vision is useful for recognition of positional relationship and relative motion between themselves and objects in the environment. So, we address the problem of navigation for mobile robot in indoor environment. To this task, we tackle the problem using monocular vision, i.e., without other kind of sensors. Insects and some animals use tools as optical flow estimations and time to contact, to their navigation [1]. So, in this paper, we propose a method for obstacle avoidance, without constantly calculating the optical flow field, only it is calculated when the robot is close to colliding with an obstacle, and so, it uses the flow field divergence to decide which direction will should be taken. Physical experiments using a real robot have been conducted in unknown environments.