Radar Object Detection via Phase-Based Displacement Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radar-based monitoring systems for railroad crossings and intersections face challenges in accurately identifying the type and behavior of objects, leading to potential erroneous warnings due to variations in object size and orientation when measured using radar waves.
Innovation Solution
An object detection apparatus that emits frequency-swept RF transmission signals, generates complex IF signals by mixing transmitted and received signals, and uses evaluation functions and phase analysis to detect object positions and displacements, enabling accurate identification of object types and behaviors without being affected by object state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If object identification is based on size or dimensions measured by radar, then object type can be identified, but identification errors occur due to variations in object state (orientation, position)
Solution Approach 1:
The patent changes the measurement parameter from size/dimensions (which vary with object state) to displacement (which is invariant to object orientation and position). By measuring displacement in the direction of the radar beam through phase analysis of the complex IF signal, the system achieves reliable object identification that is not affected by changes in object state such as orientation or position.
2Adaptability or versatility
If radar measures object size to identify object type, then object classification is possible, but measurement accuracy decreases when object orientation or position changes
Solution Approach 1:
The patent transitions from measuring size (which is state-dependent) to measuring displacement (which is state-independent). The displacement is derived from the phase of the complex IF signal, providing a measurement that remains accurate regardless of object orientation or position, thus maintaining measurement precision while preserving object type identification capability.
3Device complexity
If only object presence is detected, then detection simplicity is maintained, but monitoring information is insufficient for accurate safety assessment
Solution Approach 1:
The patent adds a new dimension of information by measuring displacement in the direction of the radar beam, complementing the basic presence detection. This is achieved through phase analysis of the complex IF signal, which extracts displacement information without significantly increasing system complexity. The additional displacement information enables accurate safety assessment by distinguishing between safe and dangerous objects.
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
The system effectively identifies objects by measuring their displacements based on phase changes, distinguishing between stationary and moving objects, and differentiating between pedestrians, vehicles, and other objects, thereby reducing false warnings and improving monitoring accuracy.
Implementation Method 1
an object detection apparatus for detecting an object using radio waves
Implementation Method 2
receives, when the RF transmission signal emitted by the emitting unit is reflected off the object, the RF transmission signal reflected off the object as an RF reception signal
Implementation Method 3
generates, in every period, a complex IF signal based on a signal obtained by mixing the RF transmission signal with the RF reception signal
Implementation Method 4
detects a position of the object based on an evaluation function generated based on the complex IF signal generated in every period
Implementation Method 5
detects a displacement of the object based on the position of the object detected by the position detecting unit and a phase of complex reflectance of the object calculated based on the complex IF signal
Data Source
AI summary
An object detection apparatus 1 includes: an emitting unit 101 for emitting an RF transmission signal; a receiving unit 201 for receiving, if the RF transmission signal is reflected off an object, the reflected RF transmission signal as an RF reception signal; an IF signal generating unit 202 for generating, in every period, a complex IF signal based on a signal obtained by mixing the RF transmission signal with the RF reception signal; a position detecting unit 203 for detecting the position of the object based on an evaluation function generated based on the complex IF signal generated in every period; and a displacement detecting unit 204 for detecting a displacement of the object based on the position of the object and the phase of complex reflectance of the object calculated based on the complex IF signal.