Vehicle Sensor Calibration Using Rigid Modules and Stereo Triangulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle systems face challenges in accurately calibrating sensors, particularly stereo camera pairs, when the vehicle is in motion due to vibration and environmental factors, leading to instability and compromised 3D image data quality, and traditional calibration methods require offline processes that are inconvenient and limited by the vehicle's design.
Innovation Solution
A system with detached sensing modules mounted on rigid plates, each with a sensor and a calibration device, continuously calibrates relative positions using a calibration target within overlapping fields of view, allowing for flexible placement and accurate calibration of sensors while the vehicle is in use, eliminating the need for a rigid placement bar and enabling on-demand recalibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional offline calibration methods are used, then calibration can be performed initially, but the calibration becomes unstable and inaccurate when the vehicle is in motion due to vibration and environmental factors
Solution Approach 1:
The system transitions from static offline calibration to dynamic continuous calibration. The calibration target is continuously tracked by sensors while the vehicle is in motion, allowing the system to adapt to changing conditions such as vibration and environmental factors. The processor continuously calculates relative positions based on real-time sensing data, maintaining calibration accuracy despite vehicle movement.
Solution Approach 2:
The calibration process becomes continuous rather than one-time. Sensors continuously capture images of the calibration target, and the processor continuously computes relative position parameters. This ongoing calibration ensures that sensor positions remain accurately calibrated throughout vehicle operation, preventing drift and maintaining measurement precision.
2Manufacturing precision
If a rigid placement bar is used to mount stereo camera pairs, then sensor positions are fixed, but the system lacks flexibility in placement and increases device complexity
Solution Approach 1:
The system divides the mounting structure into separate sensing modules, each with its own mounting plate. Instead of requiring a single rigid placement bar connecting both cameras, each camera can be independently mounted on separate plates. The calibration target and continuous calibration process enable accurate determination of relative positions between these separated modules, providing placement flexibility while maintaining position accuracy.
Solution Approach 2:
The calibration target serves as an intermediary object that enables the system to determine relative positions between sensors without requiring a rigid physical connection. By capturing images of the calibration target from different sensor positions, the processor can calculate relative position parameters, replacing the need for a rigid placement bar with an optical/computational intermediary.
3Reliability
If sensors are continuously calibrated while the vehicle is in motion, then calibration accuracy is maintained, but the system complexity increases
Solution Approach 1:
The system performs self-calibration using its own sensors and processing capabilities. The existing sensors capture images of the calibration target, and the built-in processor automatically calculates relative position parameters without requiring external calibration equipment or manual intervention. This self-service approach maintains calibration reliability while minimizing additional system complexity.
Solution Approach 2:
The sensors serve dual functions: capturing images for navigation/control decisions and capturing images of the calibration target for calibration purposes. The processor also performs dual functions by processing both navigation-related image data and calibration data. This multi-functionality enables continuous calibration without requiring dedicated calibration hardware, reducing system complexity.
Data Source
AI summary
Embodiments provide a hardware-based mechanism to continuously calibrate a set of sensors on a vehicle while the vehicle is in motion or in use. Specifically, each sensor is mounted on a respective rigid mounting device placed on the vehicle. A secondary sensing device for calibration is also rigidly mounted on the mounting device such that the relative position between the secondary device and the camera sensor can remain unchanged. The secondary sensing devices can then be used to detect a relative distance and/or position of the same calibration target. The sensed data is then used to determine, via stereo triangulation, the relative positions of the two secondary sensing devices, which in turn indicates the relative positions of the sensors.