Vehicular Radar Sensor Alignment via Spherical Reflector Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle sensing systems using radar sensors face challenges in accurately calibrating and aligning multiple sensors to ensure precise object detection and navigation, particularly in dynamic environments and after potential misalignments such as collisions.
Innovation Solution
The implementation of a method using spherical radar reflectors placed at calibration locations exterior to the vehicle, allowing for the transmission and reception of calibration signals to determine distances and orientations of radar sensors, enabling precise calibration and alignment of the sensing system through long baseline techniques and triangulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple radar sensors are used to improve object detection coverage, then the sensing capability is improved, but the alignment and calibration complexity increases
Solution Approach 1:
A spherical radar reflector is introduced as an intermediary calibration target. The reflector receives RF signals from multiple radar sensors and reflects them back, enabling the system to measure distances and orientations relative to a known spherical target. This intermediary object simplifies the calibration process by providing a common reference point for all sensors to align against, reducing the overall system complexity despite having multiple sensors.
2Measurement precision
If sensor calibration is performed manually to ensure precision, then measurement precision is improved, but the calibration time and operational complexity increase
Solution Approach 1:
The system performs self-calibration by automatically transmitting RF signals to the spherical reflector and processing the reflected signals to determine sensor distances and orientations. The electronic control unit autonomously calculates calibration parameters without requiring manual intervention, thereby maintaining high measurement precision while significantly reducing calibration time and operational complexity.
Solution Approach 2:
Manual mechanical calibration procedures are replaced with an automated electronic system. The electronic control unit uses RF signal transmission and reflection measurements to automatically compute sensor alignment parameters, substituting manual mechanical adjustment with electronic computation and signal processing.
3Reliability
If radar sensors are realigned after collision to maintain reliability, then system reliability is improved, but the realignment process complexity increases
Solution Approach 1:
The spherical radar reflector is pre-positioned at a known location external to the vehicle before any collision occurs. After a collision, the system can immediately perform realignment by measuring distances to the pre-positioned reflector, eliminating the need for complex post-collision setup procedures. The preliminary placement of the reflector simplifies the realignment process while ensuring reliability.
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
This approach ensures accurate detection and processing of objects and infrastructure, maintaining sensor alignment and functionality even after potential misalignments, enhancing the vehicle's ability to assist drivers or operate autonomously with improved navigation and object detection capabilities.
Implementation Method 1
The reflected first calibration RF signals at least include the first calibration RF signals transmitted by the at least one of the plurality of transmitting antennas of the first radar sensor and reflected off the spherical radar reflector
Implementation Method 2
determining a first distance between the first radar sensor and the spherical radar reflector based on the received reflected first calibration RF signals
Data Source
AI summary
A method includes disposing a spherical radar reflector at a location exterior a vehicle equipped with the vehicular sensing system. The vehicular sensing system includes at least two radar sensors disposed at the vehicle and a controller that processes received radio frequency (RF) signals received by the plurality of receivers of each radar sensor of the at least two radar sensors. Calibration RF signals are transmitted by at least one transmitting antenna of a plurality of transmitters of a first radar sensor and a second radar sensor the at least two radar sensors, and reflected first calibration RF signals are received by the plurality of receivers of the first radar sensor and the second radar sensor. Based on a distance between the first radar sensor, the second radar sensor, and the spherical reflector, the vehicular sensing system determines an orientation of the first radar sensor and the second radar sensor.