Autonomous Path Planning Using Offline Graphs in Dynamic Environments

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Solution Overview

Problem

Current path planning algorithms for vehicles in dynamic environments are computationally limiting due to the generation of large graphs, leading to suboptimal solutions and abnormal system behavior, as they fail to converge to near-optimal paths efficiently.

Innovation Solution

The method involves generating an offline graph representing feasible transitions and static obstacles, and an online graph that updates in real-time to account for dynamic obstacles, allowing for a non-exhaustive search to determine a path from the current position to a destination without extensive memory allocation, enabling the vehicle to adapt to new information while maintaining long-run goals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If rapidly exploring random algorithms are used to generate graphs for path planning in dynamic environments, then the system can operate online in soft real time, but the graph creation step requires an excessive amount of time and computational resources

Engineering Contradiction:
Improvepath planning speedVSAvoidgraph creation time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent segments the path planning process into two distinct phases: an offline phase where a comprehensive graph is pre-computed using rapidly exploring random algorithms, and an online phase where only minimal updates are performed. This segmentation allows the computationally intensive graph generation to be done beforehand, while real-time operation requires only simple graph annotations and searches, thus resolving the contradiction between comprehensive path planning and real-time performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-generating the complete path planning graph offline before the vehicle operates in the dynamic environment. This preliminary graph contains all feasible paths and transitions, so that during online operation, the system only needs to annotate the graph with current state information and perform efficient searches, avoiding the time-consuming graph generation step during critical real-time operations.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If large graphs are created to ensure near-optimal path solutions, then path planning accuracy improves, but the computational time and memory requirements become excessive

Engineering Contradiction:
Improvepath planning accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the computational workload by performing the intensive graph generation offline and only performing lightweight operations online. The large, comprehensive graph ensures near-optimal path solutions, while the segmentation of computation allows this accuracy to be achieved without excessive real-time computational complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a computational copy of the environment in the form of a graph structure that can be manipulated virtually. This graphical representation allows the system to explore and evaluate numerous paths in silico, ensuring high path planning accuracy without requiring proportional physical computational resources during real-time operation, as the heavy lifting was done during offline graph creation.

Inventive Principle:
Principle #26Copying

3Loss of time

If small and shallow graphs are created to reduce computational burden, then processing time decreases, but the path planning algorithms fail to converge to near-optimal solutions

Engineering Contradiction:
Improveprocessing timeVSAvoidpath optimality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent performs the action of creating comprehensive graphs in advance during an offline phase, allowing small and shallow graphs to be used during online operation. This preliminary action ensures that near-optimal solutions are available while keeping real-time processing time minimal, as the online phase only requires simple graph annotations and searches rather than exhaustive graph generation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11999479B2Fast path planning for dynamic avoidance in partially known environments
Publication Date: 2024.06.04 AURORA FLIGHT SCIENCES CORP
  • US11999479B2 patent drawing
  • US11999479B2 patent drawing
  • US11999479B2 patent drawing

AI summary

Techniques for traversing in an environment that includes at least one obstacle, by a mobile autonomous system, to a destination in the environment, are presented. The techniques can include generating, prior to the mobile autonomous system commencing activity in the environment, a graph including a plurality of vertices representing positions in the environment and a plurality of edges between vertices representing feasible transitions by the mobile autonomous vehicle in the environment; annotating the graph with at least one edge connecting a representation of a present position of the mobile autonomous system to a vertex of the graph; determining, based on the graph, a path from the present position of the mobile autonomous system in the environment to the destination; and traversing the environment to the destination, by the mobile autonomous system, based on the path.