Vehicle Motion Vector Estimation From Radar Position Pairs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radar systems in motor vehicles struggle to determine the vehicle's displacement vector accurately, especially when they do not provide speed information for stationary elements in the environment, and methods like Iterative Closest Point (ICP) lack robustness due to limited detected positions and variable element detection.
Innovation Solution
A method involving radar systems to associate previous and subsequent positions of static environmental elements, using linear regression to determine a displacement vector, and combining this with rotational speed sensors and a Kalman filter to enhance accuracy and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a radar system provides only positions without speed information for stationary elements, then the device complexity is reduced, but the measurement precision of the vehicle's displacement vector deteriorates
Solution Approach 1:
The patent introduces an intermediary algorithmic layer that processes radar position data through association of previous and subsequent positions, cost function evaluation, and linear regression to derive displacement vectors. This intermediary processing layer compensates for the lack of direct speed information by inferring motion parameters from positional changes over time, thereby resolving the contradiction between simplified radar hardware and precise measurement requirements.
2Ease of operation
If traditional ICP method is used to determine displacement vector, then the ease of operation is improved, but the reliability deteriorates due to limited detected positions and variable element detection
Solution Approach 1:
The patent implements feedback mechanisms through iterative cost function evaluation and linear regression analysis. The system continuously refines the association between previous and subsequent positions by evaluating individual costs and adjusting the overall cost function, thereby improving reliability. This feedback loop allows the system to compensate for limited or variable detection by optimizing the matching process based on accumulated evidence.
Solution Approach 2:
The patent performs preliminary actions by pre-processing radar data to identify and associate previous positions with subsequent positions before final displacement vector calculation. The system prepares and ranks potential position pairs using cost functions in advance, ensuring that the most reliable associations are selected for the final computation, thereby improving reliability without complicating the overall operation.
3Device complexity
If the number of detected environmental elements is reduced, then the device complexity is reduced, but the measurement precision of the displacement vector deteriorates
Solution Approach 1:
The patent changes the parameters of the analysis by transitioning from raw radar position data to processed displacement vector data through linear regression. The system transforms the problem from analyzing individual detected elements to analyzing the geometric relationship between position sets, thereby maintaining precision even with reduced element count. This parameter transformation allows the system to work effectively with fewer detections while preserving measurement accuracy.
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 precise determination of the vehicle's displacement vector and speed, even with limited or variable detection, providing robustness and accuracy beyond traditional methods.
Implementation Method 1
a radar system equipping the vehicle detects elements present in the environment of the vehicle, and determines their positions relative to the vehicle
Implementation Method 2
determine by linear regression the respective characteristics of a set translation and a set rotation allowing, for the pairs of positions formed in step b), to correlate the said previous positions with the said subsequent positions
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention concerns a method for determining a movement vector (T) of a motor vehicle, in which: - a radar system of the vehicle determines, at two successive instants, positions (Oj,n, Oi,n+1), relative to the vehicle, of elements of an environment of the vehicle that are static relative to this environment, - the positions determined at these two successive instants are associated with each other in such a way as to form different pairs of positions each grouping together the preceding position and the subsequent position of a given element of the environment, and in which - the movement vector of the vehicle is determined by linear regression, based on the pairs of positions thus formed. The invention also concerns a method for determining a speed (vc) of the vehicle, and a vehicle in which these methods are implemented.