On-board Radar Stationary Object Detection via Azimuth Analysis
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Solution Overview
Problem
Conventional on-board radar systems cannot quickly determine whether an object detected near a vehicle is stationary or moving, requiring multiple position detections and thus taking time.
Innovation Solution
An on-board radar apparatus that includes an observation point detecting means and a moving object detecting means, using a dual-frequency continuous-wave method to determine if a moving object is detected based on relative speed, azimuth, and vehicle traveling speed, allowing for instantaneous determination of a stationary object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple position detections are performed to determine whether an object is stationary, then the determination accuracy is improved, but the detection time increases
Solution Approach 1:
The patent introduces a new dimension (azimuth angle) to the detection parameters. Instead of relying solely on temporal changes in position, the system uses the spatial relationship between the detected object and the antenna, combined with the attachment angle of the reception antenna, to determine whether an object is stationary. This dimensional approach allows for immediate determination without requiring multiple temporal measurements.
Solution Approach 2:
The patent changes the detection parameters from purely temporal (position at different times) to a combination of spatial parameters (azimuth angle, attachment angle, and relative speed). By using the relationship V·sin(θ-φ) where V is relative speed, θ is azimuth, and φ is attachment angle, the system can determine stationarity instantaneously based on the detected object's spatial and motion characteristics rather than requiring multiple position measurements over time.
2Reliability
If the radar apparatus uses history of position and relative speed to determine stationary objects, then the determination reliability is improved, but the response speed deteriorates
Solution Approach 1:
The patent performs preliminary calculation of the relationship V·sin(θ-φ) based on the detected object's characteristics. By pre-establishing the theoretical relationship between relative speed, azimuth, and attachment angle for stationary objects, the system can immediately compare actual measurements against this predetermined relationship to determine stationarity, eliminating the need to accumulate historical data and enabling instantaneous reliable determination.
3Area of stationary object
If the radar apparatus detects objects using conventional methods, then the detection coverage is maintained, but the detection efficiency decreases
Solution Approach 1:
The patent makes the detection system multi-functional by enabling it to perform both traditional relative speed detection and stationary object identification using the same detection infrastructure. The additional processing of azimuth and attachment angle information allows the system to simultaneously maintain comprehensive detection coverage and achieve high detection efficiency through instantaneous stationary object determination.
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
Enables rapid determination of whether an object is stationary or moving by analyzing relative speed and azimuth once, reducing the need for multiple position detections and improving detection speed.
Implementation Method 1
an on-board radar apparatus that detects an object present in the vicinity of a vehicle by irradiating radar waves as transmission waves over a predetermined angle in the vicinity of the vehicle and receiving reflected waves
Implementation Method 2
an observation point that has reflected the radar wave within the detection range
Data Source
AI summary
A radar apparatus is attached to a vehicle such that a direction at 90 degrees relative to a front-rear direction of the vehicle is included in a detection range, and transmits and receives radar waves. The radar apparatus detects an observation point relative speed that is a relative speed in relation to an observation point that has reflected the radar wave within the detection range and an observation point azimuth that is an azimuth at which the observation point is present. The radar apparatus determines that a moving object is detected when an expression expressed by V<Vs·sin ((θ-φ) is satisfied, where φ is an attachment angle that is an angle at which a center axis of a reception antenna receiving the radar wave is angled in relation to a width direction of the vehicle, V is the observation point relative speed, θ is the observation point azimuth, and Vs is a traveling speed of the vehicle.