Distance Sensor Test Device With Folded Beam Path for Wavefront Flatness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing distance sensor test benches require complex and costly procedures to verify the flatness of electromagnetic wavefronts in the quiet zone, necessitating the replacement of test fixtures and additional transmitters for calibration.

Innovation Solution

A test device with a time delay unit, test signal unit, and evaluation unit enclosed in a housing, allowing the receiving element to be positioned remotely, generates a test signal and evaluates the phase and amplitude of received signals to assess wavefront flatness without disassembling the test bench.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If test fixtures are replaced and additional transmitters are used for calibration, then wavefront flatness verification can be performed, but the procedure becomes complex and costly

Engineering Contradiction:
Improvewavefront flatness verificationVSAvoidtest bench reconfiguration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The test device is designed to perform multiple functions: it can operate as a distance sensor test device during normal testing and as a wavefront flatness verification device during calibration. The receiving element can receive both free-space waves from the distance sensor and test signals for wavefront verification, eliminating the need for separate calibration equipment

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The test device uses its own receiving element to verify wavefront flatness by receiving test signals emitted by the test bench's transmitter and beam deflector. This self-verification capability eliminates the need for external calibration equipment and complex reconfiguration procedures

Inventive Principle:
Principle #25Self-service

2Ease of operation

If test device remains in installed position, then reconfiguration is reduced, but wavefront flatness verification becomes difficult

Engineering Contradiction:
Improvetest bench reconfigurationVSAvoidwavefront flatness verification
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

A signal line acts as an intermediary connection between the receiving element and the housing containing the evaluation unit. This allows the receiving element to be positioned remotely in the quiet zone where wavefront verification is needed, while the complex evaluation electronics remain in the protected housing

Inventive Principle:
Principle #24Intermediary (Mediator)

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 cost-effective verification of wavefront flatness by allowing the test device to remain in its installed position, reducing the need for complex reconfiguration and additional transmitters, and providing accurate measurements of phase and amplitude deviations.

Implementation Method 1

a receiving element (3) for receiving an electromagnetic free-space wave as a received signal

Methodology Applied
Scientific EffectElectromagnetic wave propagation: Electromagnetic Induction

Implementation Method 2

the received signal or a received signal derived from the received signal is passed through a time delay unit (5) with a predefinable time delay and is thus time-delayed to a time-delayed signal

Methodology Applied
Scientific EffectTime delay:

Implementation Method 3

a radiating element (4) for emitting an electromagnetic output signal

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP4109125B1Test device for testing a distance sensor operating with electromagnetic waves and method for checking a distance sensor test object with a folded beam path
Publication Date: 2025.11.05 DSPACE SE & CO KG
  • EP4109125B1 patent drawingFigure 1a~1b
  • EP4109125B1 patent drawingFigure 2~3
  • EP4109125B1 patent drawingFigure 4~5

AI summary

A test device (1) for testing a distance sensor (2) operating with electromagnetic waves is described and illustrated, comprising a receiving element (3) for receiving an electromagnetic free-space wave as a received signal (SRX), and a radiating element (4) for emitting an electromagnetic output signal (STX), wherein in a simulation operation the received signal (SRX) or a received signal (S'RX) derived from the received signal (SRX) is passed through a time delay unit (5) with a predefinable time delay (tdelay, soll) and is thus time-delayed to a time-delayed signal (Sdelay) as a simulated reflection signal, wherein the time-delayed signal (Sdelay) or a time-delayed signal (S'delay) derived from the time-delayed signal (Sdelay) is emitted as an output signal (STX) via the radiating element (4).The test device (1) allows a distance sensor test stand (6) to be checked with minimal effort by generating a test signal (Stest) in a test operation using a test signal unit (9) and emitting the test signal (Stest) or a test signal (S'test) derived from the test signal (Stest) as an output signal (STX) via the emitting element (4), wherein an evaluation unit (10) evaluates the received signal (SRX) or the derived received signal (S'RX) with regard to its phase (Phi) and/or amplitude (A) in the test operation synchronously with the emission of the test signal (Stest) or the derived test signal (S'test) as an output signal (STX) and stores the determined value for the phase (Phi) and/or the amplitude (A).