Robot Path Planning With Static-Dynamic Obstacle Separation
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Solution Overview
Problem
Existing robotic path planning methods are inadequate in handling both static and dynamic obstacles in uncertain environments, as they either fail to guarantee real-time adjustments for moving obstacles or can trap the robot due to conflicting repulsive speeds from multiple obstacles.
Innovation Solution
A method that involves generating static and dynamic distance maps using depth information from the environment, classifying obstacles based on their vibration range, and calculating repulsive speeds to avoid dynamic obstacles while maintaining a collision-free trajectory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If grid-based path planning methods are used to ensure complete exploration of all possible moves, then path planning completeness is improved, but planning speed deteriorates making real-time adjustment impossible
Solution Approach 1:
The patent segments the path planning problem into two distinct parts: global path planning using grid-based methods for completeness, and local real-time adjustment using artificial potential field methods for speed. This segmentation allows each method to operate in its optimal performance zone without compromising the other.
Solution Approach 2:
The patent introduces dynamic adjustment mechanisms where the robot can switch between global and local planning modes based on real-time conditions. The system dynamically recalculates paths when obstacles are detected, combining the thoroughness of grid-based planning with the responsiveness of potential field methods.
2Speed
If artificial potential field-based path planning is used to enable fast response to moving obstacles, then planning speed is improved, but the robot may be trapped in the middle of obstacles due to conflicting repulsive speeds
Solution Approach 1:
The patent applies counterweight principles by introducing escape speed as a counteracting force to the repulsive speeds that cause trapping. When the robot detects it is trapped between obstacles, the escape speed mechanism generates a force in the opposite direction to break the stalemate and enable the robot to escape the trap.
Solution Approach 2:
The patent introduces an intermediary mechanism (escape speed calculation) that mediates between conflicting repulsive forces. This intermediary component analyzes the trap condition and introduces a new velocity component that resolves the conflict and guides the robot out of the trapped state.
3Reliability
If individual repulsive speed is generated for each obstacle to avoid collision, then collision avoidance capability is improved, but the combined repulsive speeds may cancel each other resulting in null motion
Solution Approach 1:
The patent implements feedback mechanisms where the system continuously monitors the combined repulsive speeds and detects when they result in null motion. When trapping is detected, the escape speed mechanism provides corrective feedback by introducing a new velocity component that breaks the stalemate and restores motion.
Solution Approach 2:
The patent changes the parameter space by introducing escape speed as an additional degree of freedom. Instead of only adjusting the magnitude and direction of repulsive speeds, the system introduces a new parameter (escape velocity) that fundamentally alters the motion dynamics when trapping occurs, enabling the robot to escape from otherwise inescapable configurations.
Data Source
AI summary
The present disclosure relates to robot path planning. Depth information of a plurality of obstacles in an environment of a robot are obtained at a first time instance. A static distance map is generated based on the depth information. A path is computed for the robot based on the static distance map. At a second time instant, depth information of one or more obstacles is obtained. A dynamic distance map is generated based on the one or more obstacles, wherein for each obstacle that satisfies a condition: a vibration range of the obstacle is computed based on a position of the obstacle and the static distance map, and the obstacle is classified as a dynamic obstacle or a static obstacle based on a criterion associated with the vibration range. A repulsive speed of the robot is computed based on the dynamic distance map to avoid the dynamic obstacles.