Radar Antenna Offset for 3D Calibration
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Solution Overview
Problem
Current radar system calibration methods for road vehicles are inefficient and require significant time, resources, and trained personnel, especially during the final stages of vehicle production, and are limited in accurately determining both azimuthal and elevation angles.
Innovation Solution
The radar system employs a modified antenna arrangement where some antenna strands are staggered relative to others, allowing for simultaneous determination of azimuthal and elevation angles, enabling precise calibration without additional complex devices and allowing for software-based fine corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional radar antenna arrangements with parallel antenna strands are used, then azimuthal angle determination is achieved, but elevation angle determination is not possible and calibration is complex
Solution Approach 1:
The patent introduces a third dimension (elevation angle) by offsetting antenna strands in the longitudinal direction. While traditional arrangements only measure azimuthal angles in the horizontal plane, the longitudinal offset creates phase differences that enable elevation angle determination, transforming a 2D measurement system into a 3D measurement system without adding complex mechanical structures.
Solution Approach 2:
The patent employs asymmetric antenna strand arrangement where at least one antenna strand is longitudinally offset relative to others. This asymmetric configuration creates distinct phase relationships for signals received from different elevation angles, enabling the evaluation unit to distinguish and measure elevation angles while maintaining the same physical antenna structure.
2Manufacturing precision
If end-off-line calibration during vehicle manufacturing is performed with existing systems, then radar system orientation is calibrated, but the process requires significant time, technical equipment, and trained personnel
Solution Approach 1:
The radar system performs self-calibration by utilizing the phase differences generated from offset antenna strands. The evaluation unit automatically determines both azimuthal and elevation angles using the inherent geometric relationships in the offset antenna arrangement, eliminating the need for external calibration equipment and trained personnel during manufacturing.
Solution Approach 2:
The system uses feedback from the phase differences measured by offset antenna strands to automatically adjust and determine accurate spatial angles. The evaluation unit continuously processes signals from all antenna strands, using the phase relationships as feedback to calculate precise azimuthal and elevation angles without external intervention.
3Measurement precision
If multiple antenna strands are used for azimuthal angle determination, then directional accuracy is improved, but the ability to determine elevation angles remains limited
Solution Approach 1:
The patent makes the antenna strand arrangement multi-functional by using the same offset configuration for both azimuthal and elevation angle determination. The phase differences generated by longitudinal offsets serve dual purposes: maintaining azimuthal accuracy through standard processing while simultaneously enabling elevation angle measurement through additional processing in the evaluation unit.
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 simplifies the calibration process, reduces production costs, and enhances the reliability of vehicle systems by enabling accurate tracking of objects, distinguishing between drivable and obstructive objects, and allows for precise software corrections without affecting sensor sensitivity.
Implementation Method 1
radar systems emit radiation in the form of electromagnetic waves with frequencies typically in the gigahertz range, which is referred to as radar radiation, and receive the radar radiation reflected by objects in the surrounding area
Implementation Method 2
The travel time of the radar radiation allows the distance between the radar system, or the antenna arrangements used for transmitting and receiving, and the object or objects reflecting the radar radiation to be determined
Implementation Method 3
the received signals of the antenna strings are evaluated against each other and/or the transmitted signals are generated relative to each other with respect to a phase and/or amplitude, so that an azimuthal angle is determined... in addition to the azimuthal angle, an elevation angle to the objects is determined
Data Source
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AI summary
The invention relates to a radar system (6) and to a method for an improved calibration of a radar system (6). The invention proposes a radar system (6) for detecting the surroundings of a road vehicle (1), comprising a transmitting antenna arrangement (7) for transmitting radar radiation (11), a receiving antenna arrangement (8) for receiving the radar radiation (14) that is reflected on objects (13) in the surroundings (12) of the road vehicle (1), and an analyzing device (15). The receiving antenna arrangement (8) and the transmitting antenna arrangement (7) each have multiple (at least two) antenna sections (91-98, 111-118, 131-139), wherein each antenna section (91-98, 111-118, 131-139) has a longitudinal direction along which the antenna section (111, 113, 115, 117) extends farther than transverse to the longitudinal direction. A number of the antenna sections (91-98, 111-118, 131-138) are arranged parallel to one another and at a distance to one another transverse to the respective longitudinal direction in each of the antenna arrangements (7, 8). The analyzing device (15) is designed to ascertain an azimuth angle (phi) on an azimuth measuring plane (20) using the received reflected radar radiation (14) for the objects reflecting the respective radar radiation (11), said azimuth measuring plane (20) being oriented perpendicularly to the longitudinal directions of the number of antenna sections (91-98, 111-118, 131-130). At least one of the multiple antenna sections (91-98, 111-118, 131-139) is offset relative to at least one other of the antenna sections (91-98, 111-118, 131-139) with respect to the longitudinal direction of the at least one other antenna section (111, 113, 115, 117) in the transmitting antenna arrangement (7) and/or in the receiving antenna arrangement (8), and the analyzing device (15) is additionally designed to determine an elevation angle (theta) for the object (13) reflecting the respective radar radiation (11), said elevation angle (theta) being determined perpendicularly to the azimuth measuring plane (20).