Agent Trajectory Derivation via Ground Plane Tracking Points

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Solution Overview

Problem

Current methods for collecting prior agent trajectories, such as those using LiDAR-based sensor systems, are expensive and limited in scalability due to the high cost of equipment and restricted geographic availability, making it impractical to collect accurate and large-scale data for applications like autonomous driving and transportation matching platforms.

Innovation Solution

The use of monocular cameras and stereo camera systems, integrated with telematics sensors, to capture and process image data for deriving agent trajectories, which involves identifying tracking points, estimating depth, and applying motion models to correct for occlusions and inaccuracies, allowing for more affordable and widespread data collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If LiDAR-based sensor systems are used to collect agent trajectories, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvetrajectory accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses monocular camera images to create a simplified copy of the depth information that would otherwise require complex LiDAR systems. By identifying tracking points in 2D images and estimating their depth through geometric relationships with the ground plane, the system replicates the trajectory measurement function of LiDAR using much simpler, cheaper hardware.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical LiDAR scanning system with an optical camera-based approach. Instead of using rotating mirrors and laser beams to actively scan the environment, the system passively captures images with a monocular camera and derives trajectory information through image processing and geometric estimation algorithms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If LiDAR-based sensor systems are deployed, then measurement precision is improved, but scalability is reduced due to high cost

Engineering Contradiction:
Improvetrajectory accuracyVSAvoiddata collection scalability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent employs inexpensive monocular cameras that can be widely distributed across many vehicles rather than expensive LiDAR systems. These low-cost sensors can be deployed at scale across large fleets, enabling massive data collection efforts that would be economically infeasible with high-cost hardware, even if individual sensor performance is lower.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If monocular cameras are used instead of LiDAR, then device complexity is reduced, but measurement precision deteriorates due to lack of direct depth information

Engineering Contradiction:
Improvesensor system complexityVSAvoiddepth estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces the ground plane as an intermediary reference that mediates between the 2D image data and 3D spatial relationships. By establishing tracking points on the ground plane and using the known geometry of the ground, the system creates a reliable reference frame that enables accurate depth estimation from monocular images without requiring complex active sensing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from 2D image coordinates to 3D world coordinates by introducing depth estimation through ground plane geometry. By mapping tracking points from the 2D image plane to 3D space using the ground plane as a reference, the system effectively adds the depth dimension to monocular vision data, enabling accurate trajectory measurement despite the inherent limitations of single-camera imaging.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Duration of action of stationary object

If tracking points are identified in occluded images, then continuity of trajectory data is improved, but measurement precision may deteriorate due to occlusion errors

Engineering Contradiction:
Improvetrajectory tracking continuityVSAvoidposition accuracy
Core Design Contradiction:
Duration of action of stationary objectVSMeasurement precision

Solution Approach 1:

The patent prepares for potential occlusions by establishing robust tracking point identification methods that can handle partial visibility. By using pixel masks to precisely identify visible portions of agents and selecting tracking points based on ground plane intersections rather than arbitrary features, the system creates a cushion against occlusion errors that maintains tracking continuity even when agents are partially hidden.

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

Data Source

PatentUS11961241B2Systems and methods for deriving an agent trajectory based on tracking points within images
Publication Date: 2024.04.16 LYFT INC
  • US11961241B2 patent drawing
  • US11961241B2 patent drawing
  • US11961241B2 patent drawing

AI summary

Examples disclosed herein may involve a computing system that is operable to (i) receive a sequence of images captured by a camera associated with a vehicle, (ii) for each of at least a subset of the received images in which a given agent is detected, (a) generate a respective pixel mask that identifies a boundary of the given agent within the image, (b) identify, as a tracking point for the given agent within the image, at least one given pixel within the pixel mask that is representative of an estimated intersection point between the given agent and a ground plane, and (c) determine a position of the given agent at the capture time of the image based on the tracking point and information regarding the ground plane, and (iii) determine a trajectory for the given agent based on the determined positions of the given agent.