Man-Machine Safety Obstacle Avoidance Path Planning Method Based on Improved Artificial Potential Field Method

Abstract

According to the speed relationship between different obstacles and mechanical arms, the present invention respectively establishes repulsive force field vector functions, and uses Pivot algorithm to improve the repulsive force field vector functions. First, the present invention acquires the pose relationship of obstacles, target points and the robot arm through the Kinetic camera. Secondly, the present invention constructs a bounding sphere at the end effector of the manipulator, judges whether an obstacle enters the bounding sphere and performs obstacle avoidance tasks, defines the gravitational field vector function, and then defines the repulsive field vector function according to the speed relationship between the obstacle and the manipulator, Mainly consider the following situations: 1) Obstacles approach the robot arm quickly, when the speed v H > v robot_end m / s, the planned new path cannot guarantee the safety of the human body. The manipulator optimizes the vector function of the repulsion field through the Pivot algorithm according to the movement direction of the man; 2) The obstacle approaches the manipulator slowly, when the speed v H < v robot_end m / s, using the conventional repulsive field vector function. Finally, the gravitational and repulsive forces are vector-combined, trajectory planning is performed, and a new path to avoid collisions is generated. When the manipulator falls into a local minimum, a time factor is introduced to cause a certain disturbance to the manipulator and quickly escape. If the person suddenly accelerates, the first situation should be reacted.

Description

technical field [0001] The invention relates to the field of path planning of a manipulator in an industrial environment, in particular to a path planning method for man-machine safety and dynamic obstacle avoidance based on an improved artificial potential field method. Background technique [0002] In the traditional industrial field, robotic arms are usually used in static environments to complete repetitive tasks such as painting, assembly, welding, and transportation. The basic operation of these tasks is to grasp objects. When the operator enters the working environment to participate in the task of the manipulator or the operating environment of the manipulator becomes dynamic, the manipulator needs to detect changes in real time, and then adjust the movement path to ensure the safety of the man-machine and complete the grasping task. [0003] The artificial potential field method is a typical local path planning method. Its basic idea is to construct an artificial po...

AI Technical Summary

Problems solved by technology

However, the above two methods do not consider the relationship between the moving speed of the manipulator and the obstacle. When the moving speed of the obstacle is too fast, the manipulator may not be able to avoid it in time, and there are certain limitations in the safety of man-machine obstacle avoidance.

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