Fast robot motion optimization with distance field

Abstract

A robot collision avoidance motion optimization technique using a distance field constraint function. CAD or sensor data depicting obstacles in a robot workspace are converted to voxels, and a three-dimensional binary matrix of voxel occupancy is created. A corresponding distance map matrix is then computed, wherein each cell in the distance map matrix contains a distance to a nearest occupied cell. The distance map matrix is used as a constraint function in a motion planning optimization problem, wherein the optimization problem is convexified and then iteratively solved to yield a robot motion profile which avoids the obstacles and minimizes an objective function such as distance traveled. The distance field optimization technique is quickly computed and has a computation time which is independent of the number of obstacles. The disclosed optimization technique is easy to set up, as it requires no creation of geometry primitives to approximate robot and obstacle shapes.

Description

technical field [0001] The invention relates to the field of motion control of industrial robots, in particular to a robot collision avoidance motion planning technology, which converts obstacle data into voxels, creates a three-dimensional binary matrix of occupied and unoccupied voxels, and calculates the A distance map to the nearest occupied cell is included, and this distance map is then used as a constraint in the motion optimization calculation to compute the most efficient robot arm path to avoid obstacles. Background technique [0002] The use of industrial robots to perform a wide variety of manufacturing, assembly and material movement operations is well known. In many robot workspace environments, obstacles exist and may be in the path of robot motion. Obstacles can be permanent structures, such as machines and fixtures, or they can be temporary or movable. Large workpieces manipulated by robots can themselves be obstacles, since the robot must maneuver in or a...

AI Technical Summary

Problems solved by technology

Motion planning calculations take too long to be practical in environments where collision avoidance calculations must be performed in real-time while the robot is operating if there are more than a few obstacles in the robot's workspace

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