RADAR Object Tracking with RLS Velocity Estimation in Clutter

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Solution Overview

Problem

Existing Extended Object Tracking (EOT) solutions face challenges in grouping return points from the same object together, associating new return points with existing tracks, updating tracks, and detecting noise in RADAR sensor data from automotive applications.

Innovation Solution

The proposed solution involves processing RADAR return points using density-based spatial clustering, Recursive Least Squares filters, and Kalman Filters to accurately compute the position, velocity, length, and width of objects, while filtering out noise and associating clusters with existing tracks, and initializing new tracks based on cluster characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If density-based spatial clustering is used to group RADAR return points, then object detection accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improveobject detection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the computational process into distinct phases: return point filtering based on distance and motion criteria, density-based spatial clustering of valid points, and track association of clusters. This segmentation allows complex EOT to be broken into manageable steps, improving accuracy while controlling computational load at each stage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary filtering of return points before clustering by removing points beyond threshold distance from map features and points with insufficient ergo-motion compensated range rates. This preliminary action reduces the number of points requiring complex clustering computation, thereby reducing overall computational complexity while maintaining detection accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple RADAR time-steps are accumulated to increase point density, then tracking accuracy is improved, but processing time increases

Engineering Contradiction:
Improvetracking accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent accumulates return points from multiple periodic RADAR time-steps to increase point density for clustering. By processing returns from several sequential time steps, the system improves tracking accuracy through better object shape and motion estimation while managing processing throughput.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuous tracking by associating clusters from current time-step with existing tracks and updating track states. This continuity allows the system to leverage historical track information, reducing the need for complete re-processing and thereby managing processing time while maintaining accuracy.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If Linear Kalman Filters are used for velocity estimation, then computation efficiency is improved, but handling of non-linear motion dynamics is reduced

Engineering Contradiction:
Improvecomputation efficiencyVSAvoidhandling of non-linear motion
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent introduces an intermediary velocity estimation step that computes velocities from cluster positions before feeding them to the Linear Kalman Filter. This intermediary computation transforms the problem into a form suitable for linear filtering, improving computation efficiency while the filter updates track states based on these estimated velocities.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the state parameters of the track to include position, velocity, length, and width, and uses Linear Kalman Filters to update these parameters efficiently. By carefully selecting and updating only the necessary parameters, the system achieves computation efficiency while adequately representing object motion dynamics.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If return points are filtered by distance from map features and motion criteria, then noise rejection is improved, but false negatives increase

Engineering Contradiction:
Improvenoise rejectionVSAvoiddetection completeness
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies different filtering criteria to return points based on their local characteristics: distance from prior map features and ergo-motion compensated range rates. By applying localized quality filters adapted to the specific context of each return point, the system improves noise rejection while minimizing false negatives through context-aware filtering.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS11774575B2Extended object tracking using RADAR
Publication Date: 2023.10.03 MOTIONAL AD LLC
  • US11774575B2 patent drawing
  • US11774575B2 patent drawing
  • US11774575B2 patent drawing

AI summary

Techniques are provided for extended object tracking using RADAR return points only. The techniques include receiving the return points from at least one RADAR sensor of the vehicle. One or more clusters based on or from the return points are generated. An estimated position and velocity of each of the one or more clusters is computed. A Recursive Least Squares (RLS) based algorithm is proposed to estimate the instantaneous velocity of a cluster in real-time that allows for accurate track-cluster association, removes the need to perform computationally expensive non-linear state updates, and allows for the estimation of the true velocity even in frames with a large amount of clutter. If it is determined that the one or more clusters are associated with an existing object track, the existing object track is updated using at least the respective positions of the one or more clusters associated with the existing object track.