An Improved BCM Obstacle Avoidance Algorithm for Outdoor Patrol Robot

Security Patrol Robot was used to inspect the abnormal situation in the alert zone. To detect the hanging obstacles, a stereo sensing system was designed, which was composed of a full range of ultrasonic sensors with three-dimensional layout. Using obstacle distribution data acquired in this system, the improved BCM algorithm was proposed to guide robot to avoid obstacles. In the algorithm, the ranging information acquired by the three layers´ sensors was mapped into the horizontal plane. And then with the constraints from the kinematics and dynamics of robot, overlapping simplified beams were constructed from the two dimensional distribution of obstacles. After the optimization beam searching, the corresponding angular velocity and the line speed were calculated and put out to control the robot to avoid vehicles and pedestrians on the road. Finally, in the experiments of campus environment, the effectiveness of the proposed algorithm was demonstrated.