Radar Sensor Online Calibration via Reconstructed Array Manifold
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radar sensors used in vehicles for driver assistant systems and autonomous driving require calibration, but existing offline-calibration methods are time-consuming and unreliable when the sensor is mounted in a vehicle due to environmental factors, necessitating a more efficient and robust calibration method.
Innovation Solution
A computer-implemented method for calibrating radar sensors by acquiring radar detections, determining the angle of arrival, defining equidistant bins of electric angle, assigning detections to these bins, and calculating a reconstructed array manifold, which allows for online calibration without factory calibration, improving reliability and computational efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If offline-calibration is performed in an anechoic chamber, then calibration accuracy is improved, but calibration time increases and the process becomes more complex
Solution Approach 1:
The radar sensor performs self-calibration by utilizing reflections from its own transmitted signal off nearby objects in the environment. The sensor independently determines angles of arrival and processes radar detections without requiring external calibration equipment or facilities, thereby eliminating time-consuming offline calibration processes while maintaining accuracy through environmental feature utilization.
Solution Approach 2:
Environmental objects serve as intermediary calibration targets, replacing the need for specialized anechoic chamber facilities. These objects reflect radar signals back to the sensor, enabling calibration through naturally available features in the operational environment rather than requiring controlled laboratory conditions.
2Measurement precision
If offline-calibration is performed in an anechoic chamber, then calibration accuracy is improved, but device complexity and facility requirements increase
Solution Approach 1:
The radar sensor independently performs calibration using its own transmitted signals and environmental reflections. No external calibration equipment, anechoic chambers, or specialized facilities are required. The sensor processes its own radar detections and determines calibration parameters autonomously, dramatically reducing facility complexity and cost.
Solution Approach 2:
The calibration process extracts necessary calibration information from naturally available environmental features rather than requiring specialized calibration facilities. By taking out the dependency on anechoic chambers and external calibration equipment, the system achieves calibration using only the radar sensor and environmental objects.
3Ease of manufacture
If factory calibration is performed, then initial calibration is provided, but the calibration becomes unreliable when the sensor is mounted in a vehicle due to environmental factors
Solution Approach 1:
The calibration approach transitions from static factory calibration to dynamic online calibration. The sensor continuously adapts to changing environmental conditions by performing real-time calibration using current environmental features. This dynamic process ensures calibration remains accurate despite variations in vehicle mounting conditions, temperature, humidity, and other environmental factors.
Solution Approach 2:
The calibration parameters are continuously updated based on real-time environmental measurements rather than relying on fixed factory calibration values. By changing calibration parameters dynamically according to current environmental conditions, the system maintains reliability in the variable vehicle environment where temperature, pressure, and physical obstructions may differ from factory conditions.
Data Source
AI summary
A method is provided for calibrating a radar sensor. According to the method, a plurality of radar detections is acquired via the radar sensor, and an angle of arrival is determined for each of the radar detections. Equidistant bins of an electric angle are defined which are related to the angle of arrival, and the radar detections are assigned to the equidistant bins of the electric angle. Based on the assignment, a reconstructed array manifold is determined for calibrating the radar sensor.