Robot Path Planning With Weighted Obstacle Distance Costs

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Solution Overview

Problem

Existing robot path planning methods require expanding obstacles to ensure safety, leading to oversized obstacle distances and sub-optimal path planning.

Innovation Solution

A deterministic method for robot path planning that computes a minimum distance to obstacles without expanding them, using a weighting parameter to balance joint angle costs and obstacle-distance costs in the cost function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If obstacles are expanded to ensure safety distance, then robot safety is improved, but obstacle size becomes oversized and path optimality deteriorates

Engineering Contradiction:
Improverobot safetyVSAvoidpath optimality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The cost function is designed in advance to incorporate both joint angle costs and obstacle-distance costs with weighted parameters. By pre-defining the cost function structure with appropriate weighting, the system achieves safety without requiring obstacle expansion, thus avoiding the sub-optimal paths caused by oversized obstacles.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces weighting parameters (λ1 and λ2) that balance the joint angle cost and obstacle-distance cost in the total cost function. By adjusting these parameters, the system can dynamically control the trade-off between safety margins and path optimality, eliminating the need for fixed obstacle expansion while maintaining robot safety.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If deterministic methods are used to minimize cost function, then path fixedness is improved, but computational complexity increases

Engineering Contradiction:
Improvepath fixednessVSAvoidcomputational complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cost function is segmented into distinct components: joint angle cost (weighted by λ1) and obstacle-distance cost (weighted by λ2). This segmentation allows the deterministic optimization to process manageable sub-components separately, reducing overall computational complexity while maintaining path fixedness through systematic minimization of the total cost.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12325136B2Deterministic robot path planning method for obstacle avoidance
Publication Date: 2025.06.10 EDDA TECHNOLOGY INC
  • US12325136B2 patent drawing
  • US12325136B2 patent drawing
  • US12325136B2 patent drawing

AI summary

The present teaching relates to a method and system for path planning. A target is tracked via one or more sensors. Information of a desired pose of an end-effector with respect to the target and a current pose of the end-effector is obtained. Also, a minimum distance permitted between an arm including the end-effector and each of at least one obstacle identified between the current pose of the end-effector and the target is obtained. A weighting factor previously learned is retrieved and a cost based on a cost function is computed in accordance with a weighted smallest distance between the arm including the end-effector and the at least one obstacle, wherein the smallest distance is weighted by the weighting factor. A trajectory is computed from the current pose to the desired pose by minimizing the cost function.