Multi-LIDAR Alignment Validation for Online Vehicle Recalibration

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Solution Overview

Problem

Existing vehicle object detection systems, particularly LIDAR systems, face challenges in accurately aligning multiple LIDAR sensors, which affects the accuracy of perception and localization operations, especially under dynamic conditions, and requires periodic recalibration but lacks efficient online validation methods due to the absence of predetermined target objects.

Innovation Solution

A LIDAR-to-LIDAR alignment system that includes an autonomous driving module configured to validate sensor alignment by aggregating data from multiple LIDAR sensors in a vehicle coordinate system, determining differences in pitch, roll, yaw, and translation, and recalibrating sensors as needed, using methods such as ground fitting, point cloud registration, and weighted sums of difference values to ensure alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple LIDAR sensors are used for vehicle object detection, then the coverage and detection capability are improved, but the alignment accuracy and system complexity worsen due to the difficulty of maintaining precise alignment between multiple sensors under dynamic conditions

Engineering Contradiction:
Improvedetection coverageVSAvoidalignment accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The system continuously validates LIDAR sensor alignment by comparing point cloud data from multiple sensors against a vehicle coordinate system, detecting deviations in pitch, roll, and yaw. When misalignment is detected, the system triggers recalibration procedures, creating a closed-loop feedback mechanism that maintains alignment accuracy despite dynamic operating conditions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-validation and self-calibration of LIDAR sensors using onboard computational resources. The autonomous driving module automatically processes point cloud data, detects alignment issues, and initiates recalibration without external intervention, enabling the system to maintain its own alignment accuracy

Inventive Principle:
Principle #25Self-service

2Measurement precision

If periodic recalibration of LIDAR sensors is performed, then the alignment accuracy is maintained, but the loss of time and operational interruptions increase

Engineering Contradiction:
Improvealignment accuracyVSAvoidrecalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system transitions from static periodic recalibration to dynamic continuous validation. Alignment validation occurs continuously during normal operation based on real-time point cloud data analysis, allowing the system to detect and correct alignment issues immediately rather than waiting for scheduled recalibration intervals

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The validation process operates continuously during vehicle operation, constantly monitoring LIDAR sensor alignment through point cloud aggregation and analysis. This continuous monitoring eliminates gaps between recalibration events, ensuring alignment accuracy is maintained without interrupting vehicle operations

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If online validation of LIDAR alignment is implemented, then the reliability of perception operations is improved, but the computational complexity and processing requirements worsen

Engineering Contradiction:
Improveperception reliabilityVSAvoidvalidation system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The validation process is divided into distinct computational stages: point cloud aggregation from multiple sensors, coordinate system transformation to a common reference frame, alignment validation through pitch/roll/yaw comparison, and recalibration triggering. This segmentation allows the complex validation task to be processed in manageable steps using existing autonomous driving computational infrastructure

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12174301B2Online validation of LIDAR-to-LIDAR alignment and LIDAR-to-vehicle alignment
Publication Date: 2024.12.24 GM GLOBAL TECHNOLOGY OPERATIONS LLC
  • US12174301B2 patent drawing
  • US12174301B2 patent drawing
  • US12174301B2 patent drawing

AI summary

A LIDAR-to-LIDAR alignment system includes a memory and an autonomous driving module. The memory stores first and second points based on outputs of first and second LIDAR sensors. The autonomous driving module performs a validation process to determine whether alignment of the LIDAR sensors satisfy an alignment condition. The validation process includes: aggregating the first and second points in a vehicle coordinate system to provide aggregated LIDAR points; based on the aggregated LIDAR points, performing (i) a first method including determining pitch and roll differences between the first and second LIDAR sensors, (ii) a second method including determining a yaw difference between the first and second LIDAR sensors, or (iii) point cloud registration to determine rotation and translation differences between the first and second LIDAR sensors; and based on results of the first method, the second method or the point cloud registration, determining whether the alignment condition is satisfied.