Method of controlling an autonomous vehicle and a collision avoidance device thereof are disclosed. The method includes gathering obstacle information associated with an obstacle around a current navigation path of the autonomous vehicle and vehicle information associated with the autonomous vehicle. The method further includes determining a relative velocity and a collision distance between the obstacle and the autonomous vehicle and an obstacle state of the obstacle based on an analysis of the obstacle information and the vehicle information. The method includes computing a collision factor based on the relative velocity and the obstacle state. When the collision factor is above a collision threshold, the method includes stopping the autonomous vehicle before exhausting the collision distance when at least one alternate navigation path is not available, or modifying the current navigation path of the autonomous vehicle when the at least one alternate navigation path is available.