Radar Device Radome Dirt Detection via Unmodulated Pulse
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Solution Overview
Problem
Conventional radar devices face challenges in rapidly and reliably detecting dirt adhered to the radome surface without causing misdetection, particularly in FM systems where signal interference from objects complicates dirt detection, and in varying road surface conditions.
Innovation Solution
A radar device that includes transmitting and receiving means for generating a beat signal, unmodulated pulse transmission for specific timing, A/D conversion of the beat signal, and dirt detection based on the output, allowing for reliable and rapid dirt detection on the radome surface without interference from object signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the low frequency component is used for dirt detection in the FM system, then dirt detection can be performed without additional sensors, but misdetection occurs when object signals are superimposed on the low frequency component
Solution Approach 1:
The patent segments the detection process into two independent parts: (1) object detection using the low frequency component of the beat signal, and (2) dirt detection using a separate detection signal transmitted through the radome. This segmentation allows both functions to operate independently, eliminating the interference problem where object signals contaminated the dirt detection in conventional systems.
Solution Approach 2:
The patent introduces an intermediary detection signal (unmodulated pulse or high-frequency modulated wave) that serves as a dedicated probe for dirt detection. This intermediary signal interacts only with the radome and dirt, separate from the FM detection signal, thereby acting as a mediator that enables dirt detection without being affected by object reflections.
2Reliability
If the dirt detection process is prevented when objects are detected, then misdetection is avoided, but dirt detection cannot be executed rapidly
Solution Approach 1:
By segmenting the detection signals into separate frequency bands and functional categories, the system allows simultaneous execution of object detection and dirt detection without mutual interference. The detection judgment unit can independently evaluate both functions, enabling rapid dirt detection even when objects are present in the detection range.
Solution Approach 2:
The radar device achieves multi-functionality by using a single antenna system to perform both object detection and dirt detection simultaneously. The detection signal serves dual purposes: it probes the radome condition for dirt detection while the beat signal continues to detect objects, making the system universal without requiring separate sensor systems.
3Reliability
If conventional road surface detection methods are used, then dirt adhesion can be detected through reflected wave level changes, but misdetection occurs due to various road surface conditions and driving circumstances
Solution Approach 1:
The patent uses an unmodulated pulse or high-frequency modulated wave as an intermediary detection signal that interacts with the radome and dirt regardless of external conditions. This intermediary approach creates a controlled detection mechanism that is independent of road surface variations, weather, and driving circumstances, thereby achieving robust dirt detection across diverse environments.
Solution Approach 2:
The patent changes the detection parameter from monitoring reflected wave level variations (which are sensitive to environmental factors) to measuring the characteristics of a dedicated detection signal transmitted through the radome. By changing to a controlled detection signal with known properties, the system achieves consistent dirt detection performance across varying environmental conditions.
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 accurate and swift detection of dirt on the radome surface, preventing misdetection and ensuring continuous radar performance, especially in conditions where object signals might interfere with dirt detection.
Implementation Method 1
transmitting means for transmitting an electric wave as a transmission signal
Implementation Method 2
receiving means for receiving a reflected wave resulting from reflecting the transmission signal from an object
Implementation Method 3
detecting means which mixes the transmission signal and the reception signal together to generate a beat signal
Implementation Method 4
unmodulated pulse transmitting means for modifying an unmodulated wave into a pulse and transmitting the pulse
Data Source
AI summary
A radar device can reliably, and rapidly detect dirt adhered to a radome surface without misdetection. The radar device includes a transmit/receive shared antenna (306) that transmits an electric wave to an object and receives a reflected wave that has been reflected from the object, a mixer (307) that mixes a transmission signal and a reception signal together to generate a beat signal, and a signal processing unit (312) that measures a distance to the object and a relative speed of the object on the basis of the beat signal. The transmit/receive shared antenna (306) modulates an unmodulated wave into a pulse and transmits the pulse modulated wave at a specific timing. In the case where the unmodulated pulse is transmitted, the beat signal that has been generated by the mixer (307) is converted into a digital voltage value by an A/D converter (310). The signal processing unit (312) detects the dirt that is adhered to the radome (314) of the transmit/receive shared antenna (306) on the basis of an output of the A/D converter 310.