Radar Cross Section Compensation for Vehicle Sensor Calibration

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Solution Overview

Problem

Autonomous vehicles equipped with multiple radar sensors face challenges in accurately calibrating their radar cross-section measurements due to discrepancies between sensors, such as differences in manufacturer, model, occlusion, and exposure to environmental factors, leading to potential misinterpretation of the vehicle's environment and increased risk of accidents.

Innovation Solution

A radar cross-section (RCS) compensation function is generated by processing raw RCS returns into angle-based bins, applying noise-reducing filters, and smoothing the data, which is then used to correct sensor measurements, ensuring accurate calibration and reducing noise across the field of view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple radar sensors are used to expand field of view, then coverage area is improved, but measurement precision deteriorates due to sensor discrepancies

Engineering Contradiction:
Improvefield of view coverageVSAvoidradar cross section measurement accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by developing compensation functions that adjust radar cross section measurements based on angular position and sensor-specific characteristics. These functions modify the measurement parameters to account for systematic discrepancies between sensors, allowing multiple sensors to work together with improved precision while maintaining expanded field of view coverage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback mechanisms where calibration data from multiple sensors is continuously analyzed and compensation functions are updated. The system uses measured discrepancies to refine correction algorithms, creating a closed-loop system that improves measurement precision across all sensors while preserving the multi-sensor field of view advantage.

Inventive Principle:
Principle #23Feedback

2Duration of action of moving object

If sensors are exposed to environmental factors for extended operation, then duration of action is improved, but reliability deteriorates due to measurement drift

Engineering Contradiction:
Improvesensor operational durationVSAvoidmeasurement consistency
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by performing calibration and generating compensation functions before extended operational periods. The system pre-characterizes sensor behavior under various environmental conditions and creates correction algorithms in advance, enabling reliable measurements throughout extended operation without requiring continuous recalibration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements ongoing feedback mechanisms where calibration data is continuously collected and analyzed to update compensation functions. This feedback loop detects and corrects measurement drift caused by environmental exposure, maintaining reliability over extended operational durations while allowing sensors to remain in service longer.

Inventive Principle:
Principle #23Feedback

3Device complexity

If raw RCS data is processed without compensation, then device complexity is reduced, but measurement precision deteriorates due to noise and discrepancies

Engineering Contradiction:
Improvedata processing complexityVSAvoidRCS measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by transforming raw RCS measurements into compensated values using angular-position-dependent correction functions. This process adjusts measurement parameters to eliminate systematic errors while maintaining a relatively simple processing architecture that can be implemented in existing radar systems.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces compensation functions as intermediary elements between raw sensor data and final measurements. These functions act as mediators that correct discrepancies and reduce noise without requiring complex processing architectures, enabling improved precision while keeping device complexity manageable through mathematically-based corrections.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The RCS compensation function improves the accuracy and reliability of radar sensor calibration, enhancing the vehicle's ability to detect objects accurately and reducing the risk of accidents by providing a robust understanding of its environment.

Implementation Method 1

A radar sensor of a vehicle receives a plurality of radar sensor returns during a calibration time period

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

radio detection and ranging (RADAR) sensor system

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentUS11754672B2RADAR cross section compensation for calibration of vehicle RADAR
Publication Date: 2023.09.12 GM CRUISE HOLDINGS LLC
  • US11754672B2 patent drawing
  • US11754672B2 patent drawing
  • US11754672B2 patent drawing

AI summary

One or more radar sensors coupled to a vehicle receive readings during a calibration time period. Each radar sensor receives data covering a field of view of the sensor, which may be split into angle-based bins. A noise-reducing filter (e.g., median filter) may be applied. A function is generated by processing raw radar cross section (RCS) returns into values plotted against angles compared to the direction that the sensor is facing. The function may be smoothed. Radar sensor measurements captured after calibration are corrected using the function, for example by automatically subtracting or dividing amounts corresponding to the function.