Monocular Camera Time to Collision Estimation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for estimating time to collision (TTC) in Advanced Driver Assistance Systems (ADAS) and Autonomous Driving rely heavily on costly Lidar and radar technologies, which are not feasible for consumer vehicles and have poor angular resolution.

Innovation Solution

A computer vision system using a monocular camera estimates TTC by determining the 3D position and velocity of detected objects relative to the camera, incorporating a ground plane estimation and Kalman filters to compute the TTC based on distance, projected velocity, and acceleration, while determining if objects are in the vehicle's trajectory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Lidar is used for TTC estimation, then measurement precision is improved, but cost increases significantly

Engineering Contradiction:
ImproveTTC estimation accuracyVSAvoidsystem cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses a monocular camera to capture 2D images and computationally reconstructs 3D information, effectively creating a virtual copy of Lidar's depth perception capability through software algorithms rather than expensive hardware

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/optical Lidar system with a computational vision system using a standard camera and image processing algorithms, substituting physical measurement mechanisms with computational methods

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

2Ease of manufacture

If radar is used for TTC estimation, then cost is reduced, but angular resolution deteriorates

Engineering Contradiction:
Improvesystem costVSAvoidangular resolution
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent transitions from radar's limited angular measurement to computer vision's pixel-based 2D spatial resolution, adding dimensional precision through the camera's sensor array which provides much finer angular discrimination in the visual spectrum

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

3Ease of manufacture

If monocular camera is used for TTC estimation, then cost is reduced, but 3D position computation complexity increases

Engineering Contradiction:
Improvesystem costVSAvoidcomputation complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts 3D position information from 2D images by isolating and processing specific features (object detection, ground plane intersection points) separately from the full image data, reducing computational burden through selective analysis

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces intermediate computational steps including object detection, ground plane estimation, and feature point extraction as mediators between the raw 2D image and the final 3D position calculation, breaking down the complex problem into manageable stages

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11615629B2Estimation of time to collision in a computer vision system
Publication Date: 2023.03.28 TEXAS INSTRUMENTS INC
  • US11615629B2 patent drawing
  • US11615629B2 patent drawing
  • US11615629B2 patent drawing

AI summary

A method for estimating time to collision (TTC) of a detected object in a computer vision system is provided that includes determining a three dimensional (3D) position of a camera in the computer vision system, determining a 3D position of the detected object based on a 2D position of the detected object in an image captured by the camera and an estimated ground plane corresponding to the image, computing a relative 3D position of the camera, a velocity of the relative 3D position, and an acceleration of the relative 3D position based on the 3D position of the camera and the 3D position of the detected object, wherein the relative 3D position of the camera is relative to the 3D position of the detected object, and computing the TTC of the detected object based on the relative 3D position, the velocity, and the acceleration.