In-Air Sonar Doppler Mapping for Object Location and Velocity
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Solution Overview
Problem
In-air sonar systems face limitations in determining object location and velocity due to slower sound propagation, leading to inaccurate navigation decisions and difficulty in distinguishing between stationary and moving objects, especially in harsh environments.
Innovation Solution
An in-air sonar system using at least two emitters emitting low-cross-correlation sound signals, such as PR-AWGN, and multiple receivers to calculate velocity-dependent range maps, derive range-direction maps, and extract object locations and velocities through Doppler effect exploitation and clustering algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If in-air sonar is used to detect objects in harsh environments, then detection capability in mud, dust, fog, and water spray is improved, but the location determination rate is reduced due to slow sound propagation speed
Solution Approach 1:
The patent segments the detection process by using multiple emitters and receivers to simultaneously capture spatial information from different positions. This parallel acquisition of data from multiple spatial points enables the system to process more information in each time window, effectively compensating for the slower update rate caused by sound propagation delays.
Solution Approach 2:
The patent transitions from traditional single-dimension sonar detection to multi-dimensional detection by incorporating spatial diversity through multiple emitters and receivers arranged in specific geometries. This dimensional expansion allows the system to extract both location and velocity information simultaneously, improving the effective determination rate despite slow sound speed.
2Measurement precision
If conventional in-air sonar systems are used, then object detection is possible, but velocity determination and discrimination between stationary and moving objects is difficult
Solution Approach 1:
The patent implements a feedback mechanism where received signals are correlated with transmitted signals to detect Doppler frequency shifts. This feedback loop processes the phase changes in reflected signals to extract velocity information, enabling the system to distinguish between stationary and moving objects while maintaining accurate location detection.
Solution Approach 2:
The patent changes the analysis parameters by examining both the time-of-flight (for location) and frequency shift (for velocity) of reflected sound waves. By simultaneously analyzing these different parameters from the same signal, the system recovers both position and velocity information without requiring separate measurement systems.
3Measurement precision
If multiple emitters and receivers are used to improve location and velocity determination, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent designs the multiple emitters and receivers to serve multiple functions simultaneously: they act as both transmitters and receivers, and their spatial arrangement provides both location triangulation and velocity measurement capabilities. This multi-functionality reduces the need for separate specialized components, managing system complexity while maintaining high measurement precision.
Solution Approach 2:
The patent merges the functions of multiple emitters and receivers into a unified processing framework where all components contribute to both location and velocity determination. By combining the data from all sensors and processing them through integrated algorithms, the system achieves high precision without requiring separate independent subsystems for each measurement type.
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 discrimination between stationary and moving objects, improves detection range and resolution, and enhances navigation decisions by providing high-resolution location and velocity information.
Implementation Method 1
In-air sonar is a sound-based ranging technique that uses sound propagation to detect objects in the environment
Implementation Method 2
obtaining, from the receivers, respective received sound signals comprising the respective emitted sound signals reflected from objects in the environment
Implementation Method 3
calculating, from the respective received sound signals, velocity-dependent range maps for the respective emitted sound signals
Data Source
AI summary
An in-air sonar system is provided for determining location and velocity information of objects in an environment. The in-air sonar system includes at least two emitters configured to emit respective sound signals into the environment; at least two receivers configured to receive sound signals from the environment; and a processing unit configured to perform: obtaining, from the receivers, respective received sound signals comprising the emitted sound signal reflected from objects in the environment; calculating, from the respective received sound signals, respective velocity-dependent range maps; deriving, from the calculated velocity-dependent range maps and the spatial diversity of the receivers, a velocity-dependent range-direction map comprising range information as a function of a received direction; determining therefrom a location of the respective objects; and extracting, from the velocity-dependent range maps and the spatial diversity of the receivers, a velocity of the respective objects based on the determined location.