Radar Sensor Tangential Velocity Estimation
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Solution Overview
Problem
Conventional radar sensors struggle to rapidly estimate the tangential speed of radar targets, especially when dealing with quickly moving objects or those visible only for a short duration.
Innovation Solution
A process and radar sensor design that enables a rapid estimate of tangential speed using a single measurement with a single transmission signal modulation cycle, particularly through the estimation of Cartesian speed components from individual radial speeds and aspect angles in evaluation channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional radar sensors use multiple measurement cycles with complex object models to determine lateral velocity, then measurement precision is improved, but measurement time is excessive and rapid estimation is not achieved
Solution Approach 1:
The patent segments the velocity estimation problem into two independent components: radial velocity (obtained from frequency shift) and tangential velocity (obtained from phase differences across antenna elements). This segmentation allows parallel processing of both components within a single measurement cycle, eliminating the need for sequential multi-cycle measurements while maintaining estimation accuracy.
Solution Approach 2:
The patent performs preliminary phase difference calculations across multiple antenna elements simultaneously during the single measurement cycle. By pre-computing the phase relationships and using the known geometry of the antenna array, the system prepares all necessary data for tangential velocity calculation in advance, enabling rapid estimation without waiting for subsequent measurement cycles.
2Ease of operation
If radar sensors observe angle changes over time to calculate tangential velocity, then velocity estimation is achieved, but the method is too slow for quickly moving objects or short-duration targets
Solution Approach 1:
The patent replaces the temporal observation method (mechanical time-based angle tracking) with a spatial measurement approach using phase differences across multiple antenna elements. This substitution of the measurement mechanism enables instantaneous tangential velocity determination from a single snapshot, eliminating the time requirement and making the system suitable for rapidly moving or briefly visible targets.
3Productivity
If a single measurement with single transmission signal modulation cycle is used to estimate tangential speed, then measurement time is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent transitions from one-dimensional temporal observation (single angle measurement over time) to two-dimensional spatial observation (phase differences across multiple antenna elements). This dimensional change provides additional independent measurements within the same time frame, enabling accurate tangential velocity estimation from a single measurement cycle without sacrificing precision.
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 allows for a significantly faster measurement of tangential speed, enabling quicker reaction times in driver assistance systems and improved safety, especially for vulnerable road users.
Implementation Method 1
A radar sensor, in particular for motor vehicles, with an antenna arrangement having several antennas arranged at different positions in one direction, and with a control and evaluation unit
Implementation Method 2
they measure radial distance, radial relative velocity, and angles in azimuth and/or elevation
Data Source
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AI summary
The invention relates to a method for estimating a velocity ((vx,vy)) of a radar target with a radar sensor, in particular a radar sensor for motor vehicles, based on signals which are obtained in respective evaluation channels (i) corresponding to different central antenna positions (yi) of related transmission-end and receiving-end antennas (22, 10, 12) in one direction, comprising the following steps: for the different evaluation channels (i), determining a respective individual radial velocity (vr,i) of the radar target associated with the respective evaluation channel; and estimating a velocity ((vx,vy)) of the radar target based on the determined individual radial velocities (vr,i) of the radar target, wherein the velocity ((vx,vy)) comprises information relating to a tangential velocity (vy). The invention also relates to a radar sensor for carrying out the method.