Pedestrian Detection Using Logistic Probability and Point Cloud Segmentation

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Solution Overview

Problem

Autonomous vehicles face challenges in accurately predicting pedestrian presence due to complex sensor-to-object and inter-object geometries, making it difficult to cleanly separate pedestrians from other objects in a scene, which affects safety and practicality.

Innovation Solution

A system that processes point cloud data using a logistic function and binary Bayes filter to determine the likelihood of pedestrian presence, assigning attribute values and adjusting vehicle operations, such as applying brakes, based on the probability of pedestrian presence exceeding a false alarm threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the autonomous vehicle uses traditional object detection methods to identify pedestrians, then the detection process is simple and fast, but the accuracy is insufficient due to complex sensor-to-object and inter-object geometries making it difficult to separate pedestrians from other objects

Engineering Contradiction:
Improvepedestrian detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the detection process into multiple independent components: point cloud data acquisition, object detection with bounding boxes, pedestrian presence classification using logistic functions, and probability aggregation. This segmentation allows each component to be optimized independently, improving overall detection accuracy while managing system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary classification layer that processes the relationship between detected objects and potential pedestrians. The logistic function acts as a mediator that calculates pedestrian presence probability based on object attributes and spatial relationships, rather than directly detecting pedestrians in complex scenes. This intermediary step resolves the contradiction by adding computational sophistication without requiring complete scene reconstruction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the autonomous vehicle applies aggressive braking when detecting potential pedestrians, then safety is improved, but false alarms increase due to uncertain sensor data and geometric complexities

Engineering Contradiction:
Improvesafety reliabilityVSAvoidfalse alarm rate
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback through probability aggregation and threshold-based decision making. The system continuously updates pedestrian presence probability based on multiple object detections and their attributes, then compares against a threshold to determine braking action. This feedback loop allows the system to distinguish between high-confidence and low-confidence detections, reducing false alarms while maintaining safety for true pedestrian detections.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter representation from binary detection (pedestrian/not pedestrian) to continuous probability values (0-1). By using logistic functions to model pedestrian presence probability and aggregating probabilities across multiple detections, the system can adjust its response based on confidence levels. This parameter transformation enables nuanced decision-making that balances safety and false alarm reduction.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the system processes all point cloud data to ensure complete pedestrian detection, then detection thoroughness is improved, but processing time and computational load increase significantly

Engineering Contradiction:
Improvepedestrian detection completenessVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the relevant subset of point cloud data by first detecting objects and their bounding boxes, then focusing computational resources on determining pedestrian presence within those specific regions. Rather than processing the entire point cloud, the system extracts and analyzes only the portions containing detected objects, significantly reducing processing time while maintaining detection completeness through the object-centric approach.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary object detection and bounding box generation before conducting pedestrian presence analysis. This preliminary action filters the point cloud data into manageable object-specific regions, allowing the subsequent pedestrian classification to operate on pre-segmented data. This two-stage approach maintains thoroughness by checking all detected objects while reducing computational load through early data filtering and organization.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11731662B2Autonomous vehicle system for detecting pedestrian presence
Publication Date: 2023.08.22 FORD GLOBAL TECH LLC
  • US11731662B2 patent drawing
  • US11731662B2 patent drawing
  • US11731662B2 patent drawing

AI summary

A system may receive point cloud data that includes one or more data points associated with an object that was detected by sensors of an autonomous vehicle. The system may identify a subset of the point cloud data having data points that are associated with a likelihood of a pedestrian entering a scene with the object, determine a current probability value using a logistic function that is associated with the subset of the point cloud data, determine, based at least in part on the current probability value, a probability value representing a likelihood of the pedestrian actually being present for the subset of the point cloud data, determine whether the probability value exceeds a false alarm threshold value, and in response to the probability value exceeding the false alarm threshold value, assign data points of the subset an attribute value indicative of the pedestrian being present.