Hybrid Sky-Ground Navigation for GNSS Multipath Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous mobile robots face navigation challenges due to multipath interference and insufficient line-of-sight satellite signals, which can lead to inaccurate positioning and path planning, especially in environments with obstructing objects like trees and buildings.
Innovation Solution
A hybrid sky and ground navigation system that calculates sky scores based on satellite data and ground-based information to assess the accuracy and accessibility of positions, forming a navigation map that modifies the robot's path to avoid interference and ensure reliable positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If satellite-based positioning is used for navigation, then the robot can determine its current position and follow pre-planned paths, but the positioning accuracy deteriorates in environments with multipath interference or insufficient line-of-sight satellite signals
Solution Approach 1:
The patent introduces an imaging device as an intermediary between the satellite signals and the robot's positioning system. The device captures images of the sky to detect obstructions (trees, buildings, overhangs) that block or reflect satellite signals. By analyzing these images, the system identifies multipath interference zones and adjusts positioning calculations accordingly, thereby maintaining positioning accuracy in challenging environments where traditional GNSS alone would fail
Solution Approach 2:
The system implements feedback by continuously monitoring the sky view through the imaging device and comparing it against known obstruction databases or previous observations. When obstructions are detected that may cause multipath interference, the system feeds this information back to the positioning algorithm to weight or discard affected satellite signals, thus maintaining reliable positioning despite degraded signal conditions
2Adaptability or versatility
If the robot navigates near or under large objects with complex geometries, then the robot can access diverse terrain, but the satellite signal accuracy deteriorates due to multipath interference and signal obstruction
Solution Approach 1:
The patent applies preliminary action by using the imaging device to scan and map the sky view ahead of the robot's current position. Before the robot enters zones with known or potential multipath interference (near buildings, under overhangs, among trees), the system has already identified these hazardous areas and prepared adjusted navigation paths or positioning correction factors, preventing the robot from entering problematic zones or preparing it to handle signal degradation
Solution Approach 2:
The system applies local quality by creating a spatially varying positioning model where different regions of the robot's operational environment are assigned different signal reliability weights. Areas with clear sky views receive high weights for satellite positioning, while zones identified as having obstructions or reflective surfaces (buildings, water, metal structures) receive low weights or are excluded from satellite-based positioning calculations, allowing the robot to navigate diverse terrain while maintaining accuracy in each local zone
Data Source
AI summary
Disclosed are techniques for navigating a mobile machine, such as an autonomous robot, in an environment that includes objects that may block, reflect, or distort satellite signals to be used for positioning. Satellite data may be captured from one or more satellites. An image may be captured using an imaging device that is at least partially oriented toward the one or more satellites. A set of sky scores may be calculated for a set of ground positions surrounding the mobile machine based on the satellite data and the image. Each of the set of sky scores may be indicative of an accuracy of a satellite-based position at one of the set of ground positions. The mobile machine's navigation may be modified using the set of sky scores.