Radar Doppler Model Fitting for Out-of-Plane Return Correction
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Solution Overview
Problem
Traditional radar devices fail to disambiguate between in-plane and out-of-plane returns, leading to inaccurate range and Doppler measurements, which can cause significant errors in autonomous vehicle operations.
Innovation Solution
A model fitting approach using an asymmetrical loss function that accounts for both general noise and out-of-plane returns, specifically utilizing a combination of quadratic and linear loss components to correct radar data and improve Doppler measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional radar devices use standard Doppler measurement methods, then the measurement process is simple, but the measurement precision is reduced due to out-of-plane returns
Solution Approach 1:
The patent segments the Doppler measurement process into two distinct parts: (1) traditional Doppler measurement for in-plane returns, and (2) a correction component that specifically addresses out-of-plane returns. This segmentation allows the system to handle each type of return with an appropriate method, improving overall measurement precision without completely redesigning the measurement process
Solution Approach 2:
The patent introduces an intermediary correction component that acts as a mediator between the raw Doppler measurement and the final velocity estimate. This correction component specifically targets and compensates for the erroneous contribution from out-of-plane returns, thereby improving measurement precision while maintaining the simplicity of the original measurement process
2Reliability
If traditional radar devices do not disambiguate in-plane and out-of-plane returns, then the device operation is simple, but the reliability is reduced due to inaccurate range and Doppler measurements
Solution Approach 1:
The patent extracts and isolates the erroneous contribution from out-of-plane returns from the total Doppler measurement. By identifying and separating this harmful component, the system can then apply a specific correction to remove its effect, thereby improving the reliability of autonomous vehicle operations without requiring complete reprocessing of all radar data
Solution Approach 2:
The patent changes the parameter treatment by introducing a correction term that adjusts the measured Doppler velocity. This parameter change allows the system to account for out-of-plane returns by modifying the velocity calculation in a controlled manner, improving reliability while adding only minimal processing complexity
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
The solution enhances Doppler measurement accuracy by up to 15 centimeters per second, improving the safety and efficacy of autonomous vehicle operations by correcting out-of-plane errors and enabling precise localization and sensor fusion.
Implementation Method 1
The radar device may transmit the radio waves and, based on the sensed reflection, generate a range measurement indicating the distance from the sensor to the surface, as well as any rate of change of the surface (e.g., using a Doppler measurement).
Data Source
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AI summary
Techniques for accurately determining a velocity of a radar (or ultrasonic, sonar) device and/or a moveable platform associated with the radar device may comprise fitting a model to a set of Doppler values received from the device, and determining the velocity based at least in part on the model. Fitting the model to the set may comprise determining a residual between an estimated Doppler value generated by the model and a measured Doppler value and altering a parameter of the model based at least in part on an asymmetrical loss function and the residual. The asymmetrical loss function may comprise a first portion that comprises a square of the residual and a second portion that is linearly proportional to the residual. The second portion may be based at least in part on an estimated velocity and/or estimated Doppler value and may account for out-of-plane returns.