Dynamic obstacle avoidance for manipulators using distance calculation and discrete detection

•A novel method based on distance calculation and discrete detection is proposed for avoiding dynamic obstacle timely and accurately aiming at redundant manipulators.•The arbitrarily-shaped dynamic obstacles obtained from Kinect-V2 camera in real-time are converted into their convex hulls for calculating distances.•An improved discrete collision detection is presented that can adjust detection step-size adaptively for accuracy and efficiency.

In order to avoid dynamic obstacle timely during manufacturing tasks performed by manipulators, a novel method based on distance calculation and discrete detection is proposed. The nearest distances between the links of a manipulator and the convex hull of an arbitrarily-shaped dynamic obstacle obtained from Kinect-V2 camera in real-time are calculated by Gilbert-Johnson-Keerthi algorithm, and the minimum one is defined as the closest distance between the manipulator and the obstacle. When the closest distance is less than a safe value, whether the dynamic obstacle is located in the global path of the manipulator is determined by improved discrete collision detection, which can adjust detection step-size adaptively for accuracy and efficiency. If the obstacle will collide with the manipulator, set a local goal and re-plan a local path for the manipulator. The proposed method is implemented in Robot Operating System (ROS) using C++. The experiments indicate that the proposed method can perform safe and timely dynamic avoidance for redundant manipulators in human-robot interaction.