Multi-Robot Motion Planning Using Swept-Region Force Fields
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Solution Overview
Problem
Existing robotic motion planning methods struggle with efficiently planning paths that avoid collisions and obstacles while accounting for the coordinated movement of multiple robots in shared workspaces, often leading to inefficient and potentially dangerous interactions.
Innovation Solution
An elastic path planning technique that considers the swept regions of multiple robots and generates force vectors based on traffic levels to adjust paths, ensuring safe and efficient navigation by bending paths around obstacles and avoiding high-traffic areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional path planning methods are used for multiple robots, then individual robot paths can be determined, but collision avoidance and coordination between robots deteriorates
Solution Approach 1:
The patent merges the path planning of multiple robots into a unified configuration space where all robot positions are considered simultaneously. By combining individual robot states into a composite configuration space state, the system achieves coordinated collision avoidance while maintaining manageable computational complexity through the use of potential field methods in this unified space.
Solution Approach 2:
The patent introduces configuration space as an intermediary representation that transforms the complex multi-robot coordination problem into a single-entity path planning problem. This intermediate mathematical space allows traditional path planning algorithms to handle multiple robots by treating their combined state as one composite object, thereby improving reliability without proportionally increasing complexity.
2Ease of manufacture
If artificial potential field methods are used, then path planning is simple, but the method gets stuck in local optima
Solution Approach 1:
The patent extends the traditional two-dimensional potential field method into a higher-dimensional configuration space that incorporates all robot positions and orientations. This dimensional extension allows the potential field to guide robots through complex coordination scenarios that would create local optima in lower-dimensional spaces, maintaining computational simplicity while improving path planning completeness.
Solution Approach 2:
The patent dynamically adjusts potential field parameters such as attraction and repulsion strengths based on the configuration space state and traffic conditions. By changing these parameters adaptively, the system avoids getting stuck in local optima while preserving the computational efficiency and simplicity of the potential field approach.
3Productivity
If robot paths are planned independently, then computation is fast, but coordination and conflict avoidance between robots deteriorates
Solution Approach 1:
The patent segments the configuration space into regions with different traffic levels and applies localized potential field adjustments in each region. This segmentation allows the system to maintain fast computation by processing space in manageable sections while still achieving global coordination through the continuous potential field framework that spans the entire configuration space.
Solution Approach 2:
The patent implements dynamic path planning where the potential field configuration updates in real-time based on robot positions and traffic conditions. This dynamic approach enables fast adaptation to changing conditions while maintaining coordination, as each robot's path is continuously adjusted based on the current configuration space state rather than following static pre-planned paths.
4Reliability
If elastic path planning is applied to avoid obstacles, then collision avoidance improves, but path length and computation time increase
Solution Approach 1:
The patent adjusts potential field parameters dynamically based on obstacle proximity and traffic conditions, applying stronger repulsive forces only when necessary. This parameter adaptation allows the system to maintain straight, efficient paths in open areas while providing elastic deformation around obstacles and high-traffic regions, thereby improving obstacle avoidance without significantly increasing path length or computation time.
Data Source
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AI summary
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for planning a path of motion for a robot. In some implementations, a candidate path of movement is determined for each of multiple robots. A swept region, for each of the multiple robots, is determined that the robot would traverse through along its candidate path. At least some of the swept regions for the multiple robots is aggregated to determine amounts of overlap among the swept regions at different locations. Force vectors directed outward from the swept regions are assigned, wherein the force vectors have different magnitudes assigned according to the respective amounts of overlap of the swept regions at the different locations. A path for a particular robot to travel is determined based on the swept regions and the assigned magnitudes of the forces.