High-Fidelity Micro-Doppler Radar Simulation with CAD Motion Models

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current radar simulators fail to accurately and efficiently simulate micro-motions of target objects, such as pedestrians and cyclists, leading to inefficiencies and high computational costs in radar development.

Innovation Solution

A high-fidelity radar simulator that accurately simulates the main and micro-motions of target objects by calculating Doppler and micro-Doppler shifts using ray tracing and physical optics simulations, incorporating CAD models and motion files to model human activities like walking, running, and cycling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If current radar simulators simulate micro-motions of target objects, then simulation accuracy improves, but computational cost increases significantly

Engineering Contradiction:
Improvesimulation accuracyVSAvoidcomputational cost
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the motion simulation into two distinct components: main motion (translational movement of the object) and micro-motion (local movements of body parts). By separating these motions, the system can apply different simulation methods to each component, achieving high accuracy for micro-motions while maintaining computational efficiency through selective detailed modeling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic motion modeling by applying main motion to the entire object and superimposing micro-motions on specific body parts. This dynamic approach allows the simulation to adaptively represent complex human movements (walking, running, cycling) by combining rigid body translation with localized flexible movements, improving accuracy without requiring full dynamic simulation of all object particles.

Inventive Principle:
Principle #15Dynamics

2Reliability

If live tests are performed to evaluate radar performance, then real-world performance is verified, but time and cost increase

Engineering Contradiction:
Improveperformance verificationVSAvoidtesting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent creates a virtual copy of the real-world environment and target objects through detailed CAD models and motion files. This virtual replica allows comprehensive radar performance evaluation in simulated scenarios that mirror real conditions, eliminating the need for repeated physical live tests while maintaining verification reliability.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary simulation of radar performance using accurate micro-Doppler models before conducting actual live tests. By pre-evaluating radar algorithms and parameters in the virtual environment, developers can identify and correct issues beforehand, reducing the number of iterative live tests needed and accelerating the overall development timeline.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If micro-Doppler shift is calculated for each ray, then simulation fidelity improves, but processing complexity increases

Engineering Contradiction:
Improvesimulation fidelityVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and isolates the micro-Doppler effect calculation from the general ray tracing process. By specifically identifying rays that interact with moving body parts and calculating micro-Doppler shifts only for those relevant rays, the system achieves high simulation fidelity while avoiding unnecessary computational complexity for rays that do not contribute to micro-motion signatures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies micro-Doppler calculation selectively to specific regions and rays rather than uniformly across all rays. By focusing computational resources on rays that intersect with moving body parts (arms, legs, torso) and applying local quality adjustments to those specific calculations, the system maintains high fidelity where needed while reducing overall processing complexity.

Inventive Principle:
Principle #3Local quality

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 efficient and accurate simulation of vulnerable road users, distinguishing them from other objects, reducing computational resources and time required for radar development.

Implementation Method 1

performing ray tracing simulation including launching a set of rays from a ray source towards the object and determining a set of propagation paths of the set of rays from the ray source to the object and a set of reflection paths of the set of rays from the object to a ray receiver

Methodology Applied
Scientific EffectRay tracing: Reflection

Implementation Method 2

performing physical optics simulation to determine a set of scattered fields associated with the set of reflection paths of the set of rays

Methodology Applied
Scientific EffectPhysical optics: Scattering

Implementation Method 3

calculating at least one of a Doppler shift and a micro-Doppler shift for each ray of the set of rays

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4585961A1High-fidelity micro-doppler effect simulator
Publication Date: 2025.07.16 APTIV TECHNOLOGIES AG
  • EP4585961A1 patent drawingFigure 1
  • EP4585961A1 patent drawingFigure 2
  • EP4585961A1 patent drawingFigure 3

AI summary

A computer-implemented method includes receiving environment description data associated with a simulated environment including an object and identifying an object type of the object. The method includes, in response to the object type being a human, identifying a motion type associated with the object, loading a CAD model associated with the object, loading a motion file associated with the motion type, and mapping the CAD model to the motion file. The method includes performing ray tracing simulation, performing physical optics simulation, calculating at least one of a Doppler shift and a micro-Doppler shift for each ray of a set of rays, performing ray clustering, and transforming a simulation output for display on a user device. The simulation output includes a motion simulation associated with the motion type of the object. The motion simulation includes a main motion of the object and a set of micro-motions of the object.