Distance Measurement Device Diagnostics Using Internal Delay Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distance measurement devices, such as fill level measuring devices, suffer from internal defects that cause increased measurement errors which are not easily detectable, especially when the errors are small and the displayed values appear plausible.
Innovation Solution
An integrated diagnostic unit within the device includes a diagnostic line with a delay element, allowing the measurement signal to be partially coupled into the diagnostic line, mixed with the measurement signal, and evaluated to check the functionality of the signal generator and evaluation algorithm, eliminating the need for external mechanical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical reference reflectors are used for checking distance measurement devices, then functionality can be verified, but the check is bound to mechanical design and requires external components in the measurement environment
Solution Approach 1:
The invention extracts the reference signal generation function from external mechanical components and integrates it into the device's internal electronics through a diagnostic line with delay elements. This eliminates the need for mechanical reference reflectors in the measurement environment while maintaining functionality verification capability.
Solution Approach 2:
The invention introduces an electronic intermediary (diagnostic line with delay elements) that mediates between the signal generator and the mixing stage, replacing the need for external mechanical reference reflectors. This electronic mediator generates reference signals internally, eliminating mechanical design dependencies.
2Measurement precision
If internal defects occur in signal generator or evaluation unit, then measurement errors increase, but the errors remain undetected when displayed values appear plausible
Solution Approach 1:
The invention implements a feedback mechanism where the diagnostic line generates reference signals that are mixed with received signals, and the evaluation unit compares the resulting diagnostic mixed signals against expected values. This feedback loop continuously monitors internal component performance and detects measurement errors even when displayed values appear plausible.
Solution Approach 2:
The invention performs preliminary diagnostic actions by continuously generating and evaluating diagnostic mixed signals before actual measurement errors affect the displayed values. The evaluation unit proactively checks for anomalies in the signal generator and evaluation algorithm by comparing diagnostic signals against reference values.
3Reliability
If a diagnostic line with delay element is integrated, then internal errors can be detected, but the device complexity increases
Solution Approach 1:
The invention merges the diagnostic function with the existing signal processing architecture by integrating the diagnostic line and delay elements into the current signal path. The diagnostic line is combined with the signal generator output, and the mixing stage combines diagnostic and received signals, eliminating the need for completely separate diagnostic hardware.
Solution Approach 2:
The invention makes the signal generator and mixing stage universal by enabling them to serve both measurement and diagnostic functions. The signal generator produces both measurement signals and diagnostic reference signals, while the mixing stage processes both received signals and diagnostic signals, reducing overall device complexity through multi-functionality.
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 ensures improved measurement accuracy by detecting small internal errors and verifying correct functionality, particularly relevant for functional safety, without requiring additional mechanical components in the measurement environment.
Implementation Method 1
at least one signal generator (2) for generating an electromagnetic measurement signal (Tx)
Implementation Method 2
at least one receiving antenna (4) for receiving a received signal (Rx)
Implementation Method 3
the diagnostic line (6) has at least one delay element (7), wherein the measurement signal (Tx) is formed as a diagnostic signal (Txd) after at least one pass through the delay element (7)
Implementation Method 4
a first mixer (5), wherein a first input of the first mixer (5) is connected to the signal generator (2) and wherein a second input of the first mixer (5) is connected at least to the receiving antenna (4), such that, during operation, the first mixer (5) mixes at least the measurement signal (Tx) generated by the signal generator (2) and the received signal (Rx) received by the receiving antenna (4)
Data Source
AI summary
A device for distance measurement includes a signal generator for generating a signal, a transmitting antenna for transmitting the signal, a receiving antenna for receiving a received signal, a first mixer, an evaluation unit, and a diagnostic unit having a diagnostic line. The first mixer mixes the signal and the received signal. The signal generator is connected to the diagnostic line and the signal is a diagnostic signal after passing through a delay element of the diagnostic line. The diagnostic signal is mixed with the signal in the first mixer or a second mixer to form a diagnostic mixed signal. The output of the first mixer, and the output of any second mixer, is or are connected to the evaluation unit, which uses the diagnostic mixed signal to check functionality of the signal generator and/or the evaluation algorithm.