Ultrasonic Object Detection for Close-Range Reverberation Analysis
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Solution Overview
Problem
Ultrasonic sensors face challenges in accurately measuring short distances due to reverberation effects when objects are close, leading to enhanced signal strength and prolonged reverberation times, making it difficult to determine the time of flight and calculate distance accurately.
Innovation Solution
An object detection method using ultrasonic sensors that determines reverberation duration and degree of dispersion to provide proximity information by transmitting multiple waves, judging proximity based on the trend of dispersion variation, even when objects are close to the sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the time-of-flight method is used for ultrasonic distance measurement, then distance measurement can be achieved, but measurement precision deteriorates when the object is close to the sensor due to reverberation effects
Solution Approach 1:
The patent converts the harmful reverberation effect into a useful measurement indicator. By analyzing the reverberation time and degree of dispersion of multiple transmitted waves, the system determines object proximity. The reverberation effect, which previously prevented accurate measurement, is now utilized to provide proximity information through statistical analysis of reverberation characteristics.
Solution Approach 2:
The patent changes the measurement parameter from direct time-of-flight calculation to statistical analysis of reverberation time and degree of dispersion. Instead of relying on precise TOF measurement that fails close to objects, the system uses the statistical characteristics (mean and standard deviation) of multiple reverberation time measurements to infer proximity, thereby resolving the measurement precision issue at close ranges.
2Loss of information
If multiple transmitted waves are transmitted sequentially to determine degree of dispersion, then proximity information can be provided, but device complexity increases
Solution Approach 1:
The patent employs periodic transmission of multiple ultrasonic waves sequentially and analyzes their reverberation characteristics. By transmitting waves at regular intervals and collecting reverberation time data for each wave, the system builds statistical information about the object's proximity. This periodic measurement approach provides reliable proximity information while maintaining manageable system complexity through structured data collection.
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 close-range detection by providing comprehensive information on object proximity, overcoming the limitations of conventional time-of-flight methods in ultrasonic sensors.
Implementation Method 1
the ultrasonic sensor transmits a transmitted wave in response to a drive signal, the transmitted wave contacts the object under measurement and reflects a reflected wave
Implementation Method 2
the round trip distance to the object under measurement can be calculated by measuring the time from the start of transmission to reception of the reflected wave and multiplying this time by the speed of sound
Implementation Method 3
when transmission of the drive signal to the ultrasonic sensor has ceased, a vibrator of the ultrasonic sensor will continue damped vibration
Implementation Method 4
Aftersound generated during this damped vibration is called reverberation. The reverberation time is defined as the time taken for an output voltage to attenuate to a standard voltage position
Data Source
Figure 1
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Figure 3B~4
AI summary
The present disclosure provides an object detection method, which can provide information about the distance of a detected object by means of the relationship between the distance of the detected object in a close-range area/blind zone and the dispersion of a reverberation duration when the detected object is too close to an ultrasonic sensing system and is within the blind zone of the ultrasonic sensing system, overcomes the technical prejudice of being unable to provide specific location information of the detected object when the detected object is located within the blind zone of the ultrasonic sensing system, and is particularly applicable to close-range detection in the field of motor vehicles. In addition, the present disclosure further provides a computer program product, an object detection device, and a motor vehicle, which can also provide information about the distance of a detected object when the detected object is in a close-range area/blind zone.