Ultrasonic Doppler Speed Detection for Moving Object Differentiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ultrasonic systems in driver assistance and partially automated driving lack the ability to accurately determine the speed of detected objects, relying on unreliable temporal analysis methods and failing to differentiate between static and dynamic objects, which is crucial for safe navigation and collision prevention.
Innovation Solution
The method employs a Doppler shift analysis by emitting ultrasonic pulses with defined signal profiles and calculating frequency-related cross-correlations to determine the speed of objects, allowing for real-time differentiation between static and dynamic objects based on frequency shifts, thereby enhancing the accuracy of obstacle detection and vehicle surroundings perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temporal analysis of ultrasonic signals is used to determine speed, then speed information can be obtained, but the method suffers from ambiguities and miscalculations making it unreliable
Solution Approach 1:
The patent changes the measurement parameter from temporal analysis to frequency analysis. By using frequency-related cross-correlation to detect Doppler shift in the ultrasonic signal, the system achieves reliable speed determination without the ambiguities inherent in temporal analysis methods.
Solution Approach 2:
The patent replaces the temporal analysis approach with a frequency-based spectral analysis approach. This substitution uses frequency-domain processing (cross-correlation in frequency domain) instead of time-domain analysis, eliminating the reliability issues associated with temporal methods while maintaining speed measurement capability.
2Device complexity
If ultrasonic sensors are arranged horizontally only, then the system structure is simple, but no height information (z-coordinates) can be determined
Solution Approach 1:
The patent adds a vertical dimension to the sensor arrangement. By positioning ultrasonic sensors at different heights (vertically stacked), the system can determine z-coordinates (height information) in addition to x- and y-positions, achieving three-dimensional spatial awareness without excessive complexity.
Solution Approach 2:
The patent makes the ultrasonic sensor system multi-functional. The same ultrasonic transducers used for horizontal position detection are also utilized for vertical position detection when arranged in vertical stacks, allowing a single sensor configuration to provide both 2D and 3D spatial information.
3Ease of operation
If static environment assumption is made, then the system operation is simple, but speed information of moving objects is lost
Solution Approach 1:
The patent changes the operational approach from assuming static environments to actively measuring dynamic parameters. By incorporating frequency-related cross-correlation to detect Doppler shifts, the system can determine object speeds while maintaining relatively simple operation through automated signal processing.
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 enables reliable and real-time speed determination of objects, improving the differentiation between static and dynamic objects, and allowing for more accurate obstacle detection and vehicle surroundings perception, enhancing safety in automated driving systems.
Implementation Method 1
an ultrasonic pulse having a defined signal profile is emitted by means of a first ultrasonic transducer in the direction of objects that may reflect ultrasound
Implementation Method 2
a reflected ultrasonic signal is received by means of a second ultrasonic transducer
Implementation Method 3
a Doppler shift of the frequency of the ultrasonic pulse is brought about by an object which moves toward or away from an ultrasonic transducer and which reflects an ultrasonic pulse
Data Source
AI summary
A method is for determining a speed of an object based on an ultrasonic pulse. The method includes emitting the ultrasonic pulse using a first ultrasonic transducer. The ultrasonic pulse having a defined signal profile. The method further includes receiving an ultrasonic signal using a second ultrasonic transducer, calculating a cross-correlation, with respect to frequency, of the ultrasonic signal with a filter signal which at least partially correlates with the defined signal profile, and determining a frequency shift between the filter signal and the received ultrasonic signal using a result of the calculated cross-correlation. The method also includes determining the speed of the object which reflected the emitted ultrasonic pulse using the determined frequency shift.