Probabilistic SLAM Mapping Using Geometric Priors

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Solution Overview

Problem

Current SLAM algorithms face challenges in creating accurate maps of indoor environments without prior knowledge or external references, as they rely on discrete landmarks and assume random feature structures, leading to limited map accuracy and data association issues.

Innovation Solution

A novel probabilistic formulation that registers multiple surface scans in a common coordinate frame, using geometric map representations and statistical prior models to reconstruct maps without relying on data correspondences or landmarks, incorporating manifold, smoothness, and orientation priors to estimate the robot's pose and map.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If discrete landmarks are used in SLAM algorithms, then data association becomes simpler, but map accuracy is limited and useful sensor data is discarded

Engineering Contradiction:
Improvemap accuracyVSAvoidsensor data discarded
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent extracts and removes the landmark selection step from traditional SLAM algorithms. Instead of selecting discrete landmarks and discarding other sensor data, the invention uses all raw sensor measurements directly in the probabilistic formulation, thereby eliminating information loss while maintaining computational feasibility through the prior model approach

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental parameter representation from discrete landmark coordinates to continuous raw sensor measurements. By formulating SLAM in terms of raw measurements with probabilistic priors rather than discrete landmark associations, the system achieves higher map accuracy while utilizing complete sensor data without discarding any information

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If discrete landmarks are selected for SLAM, then data association is easier, but the assumption of random feature structure limits applicability to structured environments

Engineering Contradiction:
Improveenvironment adaptabilityVSAvoiddata association reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent inverts the traditional SLAM approach by not selecting landmarks from the environment, but rather by letting the probabilistic prior model define the expected environmental structure. Instead of adapting to random feature distributions, the system imposes a structured prior model that reflects real-world environmental regularities, thereby improving both adaptability and reliability

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the fundamental assumption from random feature distribution to structured prior models. By incorporating domain knowledge about typical environmental structures into the probabilistic formulation, the system becomes more adaptable to real-world structured environments while maintaining reliable mapping through the prior constraints

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If robot pose determination is imprecise, then localization is limited, but map creation capability is also limited

Engineering Contradiction:
Improverobot pose precisionVSAvoidmapping reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent implements feedback through the probabilistic formulation where the prior model provides continuous constraints on the robot pose and map structure. The posterior distribution integrates sensor measurements with prior knowledge, providing feedback that corrects pose estimation errors and maintains reliable mapping even when individual measurements are imprecise

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies beforehand cushioning by incorporating prior models that encode expected environmental structures and robot behaviors before mapping begins. These priors act as a cushion against imprecise pose determination, preventing error propagation and maintaining mapping reliability through pre-established constraints

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8831778B2Method of accurate mapping with mobile robots
Publication Date: 2014.09.09 ROBERT BOSCH GMBH
  • US8831778B2 patent drawing
  • US8831778B2 patent drawing
  • US8831778B2 patent drawing

AI summary

A robotic mapping method includes scanning a robot across a surface to be mapped. Locations of a plurality of points on the surface are sensed during the scanning. A first of the sensed point locations is selected. A preceding subset of the sensed point locations is determined. The preceding subset is disposed before the first sensed point location along a path of the scanning. A following subset of the sensed point locations is determined. The following subset is disposed after the first sensed point location along the path of the scanning. The first sensed point location is represented in a map of the surface by an adjusted first sensed point location. The adjusted first sensed point location is closer to each of the preceding and following subsets of the sensed point locations than is the first sensed point location.