Radar Ghost Removal via Relative Speed Estimation
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Solution Overview
Problem
Existing radar devices struggle to accurately distinguish between actual targets and ghosts, particularly in complex environments like curved roads, leading to incorrect recognition of reflections as moving objects.
Innovation Solution
A method and device that detect the position and relative speed of both moving and stationary objects using radio waves, estimate the position and speed of ghosts based on these detections, and exclude ghost detection points from candidate moving object points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional ghost removal methods (virtual wall or line-based) are used, then ghost recognition is improved, but false removal of actual targets and adaptability to complex environments deteriorates
Solution Approach 1:
The patent changes the parameters used for ghost detection from simple geometric relationships (virtual wall position, line equations) to dynamic parameter relationships based on relative speed. By calculating ghost relative speed using the formula Vg = 2×Vt×cos(θ) and comparing it with detected target speeds, the system adapts to different environmental conditions and target movements, improving both ghost recognition accuracy and reliability in complex environments like curved roads
Solution Approach 2:
The patent introduces dynamic evaluation of ghost occurrence probability based on relative speed measurements. Instead of static virtual wall methods, the system continuously updates ghost speed estimates and compares them with actual target speeds, allowing the ghost removal mechanism to adapt dynamically to changing conditions while maintaining reliability in distinguishing real targets from ghosts
2Device complexity
If all targets outside the virtual wall line are removed as ghosts, then ghost detection is simplified, but loss of information about actual targets increases
Solution Approach 1:
Instead of removing all targets outside the virtual wall line (excessive action), the patent applies partial action by selectively removing only those targets whose relative speed matches the calculated ghost speed. This partial removal approach maintains simplicity while preventing false removal of actual targets, thereby reducing information loss
Solution Approach 2:
The patent replaces the mechanical geometric line-based removal system with a speed-based detection system. By substituting the rigid virtual wall concept with dynamic relative speed comparison, the system achieves more accurate ghost identification without losing information about actual targets that have different speed characteristics
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 allows for more accurate ghost detection and removal, preventing false recognition of stationary objects like pedestrians or walls as moving vehicles, enhancing the reliability of radar systems in multipath environments.
Implementation Method 1
The radar device included in this inter-vehicle distance sensor irradiates a front side of a vehicle with millimeter-wave radio waves, receives the reflected radio wave from a target
Implementation Method 2
mixes the received signal generated from the received radio wave with the transmission signal, thereby detecting a relative distance, a relative speed
Data Source
AI summary
A ghost removal method includes steps of detecting, estimating and excluding. In the detecting, a position and a relative speed of a target moving object, and a position of a surrounding stationary object are detected with radio waves. In the estimating, a position and a relative speed of a ghost by the target moving object are estimated based on the detected position and relative speed of the target moving object and the position of the surrounding stationary object. In the excluding, a detected point where the estimated position and the relative speed of the ghost are detected is excluded from a candidate detection point of a moving object which is detected with radio waves.