Radar Object Position Detection Without Phase Information
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Solution Overview
Problem
Existing obstacle detection systems using radar devices face inaccuracies in detecting multiple objects due to incorrect pairing of distance information and are affected by phase variations in signal propagation, leading to reduced accuracy, especially at low elevation angles.
Innovation Solution
The system employs multiple radar devices that calculate relative distances to detection targets without using phase information, utilizing different methods for pairing relative distances to accurately determine object positions and angles, and uses polarized waves to enhance detection probability by varying incident angles and signal intensities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase information is used to calculate distance in radar systems, then distance measurement is possible, but measurement precision deteriorates due to phase variations caused by propagation medium
Solution Approach 1:
The patent extracts and eliminates the use of phase information from the distance calculation process. Instead of using phase differences between transmission and reception signals, the system uses only frequency information from FMCW radar beat signals, thereby removing the source of phase-related errors caused by propagation medium variations.
Solution Approach 2:
The patent changes the parameter used for distance calculation from phase information to frequency information. By using the beat frequency obtained from mixing transmission and reception signals in FMCW radar, the system achieves distance measurement that is independent of phase variations in the propagation medium.
2Measurement precision
If multiple radar devices are used to detect multiple objects, then detection coverage is improved, but false detection increases due to incorrect pairing of distance information
Solution Approach 1:
The patent introduces a feedback mechanism where distance information from multiple radar devices is repeatedly paired and verified. The pairing process uses consistency checks across different radar devices to identify correct object pairings, and incorrect pairings are eliminated through iterative verification, thereby reducing false detections.
Solution Approach 2:
The patent combines distance information from multiple radar devices to form a composite detection result. By integrating measurements from multiple sources and using consistency verification, the system achieves more reliable object detection than any single radar device could provide alone.
3Measurement precision
If elevation angle of target is low, then detection coverage is maintained, but measurement precision deteriorates due to large errors in estimated relative angle
Solution Approach 1:
The patent replaces the mechanical/geometric method of angle estimation with a frequency-based distance calculation method. Instead of relying on accurate angle measurements that become problematic at low elevation angles, the system uses FMCW radar beat frequency to calculate distance directly, eliminating the dependency on angle measurement accuracy.
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 improves the accuracy of detecting multiple objects by eliminating phase-related errors and increasing pairing accuracy, allowing for precise position determination and enhanced detection probability even at low elevation angles.
Implementation Method 1
a plurality of radar devices 2A and 2B that receive, with respective reception antennas 31, reception waves obtained by transmission waves that have been transmitted from respective transmission antennas 25 being reflected back from a plurality of detection target objects
Implementation Method 2
reception waves obtained by transmission waves that have been transmitted from respective transmission antennas 25 being reflected back from a plurality of detection target objects
Implementation Method 3
a pairing means configured to perform, by using a plurality of different methods, pairing in which, of the relative distances to the plurality of detection target objects calculated by the individual radar devices, a combination of relative distances for a same detection target object is specified
Data Source
AI summary
To provide an object position detection system in which positions of detection target objects are determined with accuracy, in which pairing accuracy increases, and in which accuracy of detecting the detection target objects increases. Radar devices 2A and 2B receive, with respective reception antennas 31, reception waves obtained by transmission waves that have been transmitted from respective transmission antennas 25 being reflected back from a plurality of targets T1, T2, T3, T4, . . . , and Tm and calculate relative distances to the plurality of targets T1, T2, T3, T4, . . . , and Tm from beat frequencies between the transmission waves and the reception waves without using pieces of phase information of the transmission waves and the reception waves. An arithmetic device 4 includes a pairing means and a position calculation means.