Radar Fill-Level Measurement with Redundant HF Self-Diagnosis
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Solution Overview
Problem
Existing fill-level measurement devices face challenges in reliably detecting functional failures in their high-frequency units, particularly in radar-based systems, which are critical for safety-relevant applications due to the difficulty in recognizing analog faults and the complexity of safety compliance tests.
Innovation Solution
A fill-level measurement device with redundant high-frequency sources and receivers, allowing for functional checks by switching components on and off to assess changes in evaluation signals, ensuring the device can classify itself as non-functional if predefined properties change beyond a defined threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radar-based measurement principles are used for fill-level measurement, then measurement precision and continuity are improved, but the difficulty of detecting functional failures in high-frequency units increases
Solution Approach 1:
The high-frequency unit is segmented into multiple independent high-frequency sources and receivers that can be individually switched on and off. This segmentation allows the system to isolate and test each component's functionality separately, making it possible to detect functional failures in specific segments without affecting the entire system's measurement capability.
Solution Approach 2:
The patent implements redundant copies of high-frequency sources and receivers that can be activated to replace potentially faulty components. By having backup components, the system can compare the output of active versus inactive components to detect functional deviations, thereby identifying failures in the high-frequency units.
2Reliability
If safety-relevant fill-level measurement is implemented, then reliability is improved, but the complexity of safety compliance tests increases
Solution Approach 1:
The system performs self-diagnosis by automatically switching between different high-frequency sources and receivers and evaluating the output signals to detect functional failures. This self-service capability allows the system to monitor its own health and compliance with safety standards without requiring external complex testing procedures, thereby simplifying safety compliance while maintaining high reliability.
3Reliability
If redundant high-frequency sources and receivers are implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent employs dynamic switching between multiple high-frequency sources and receivers based on operational requirements and diagnostic needs. This dynamic configuration allows the system to activate only the necessary components for measurement while keeping others in standby or inactive states, thereby managing complexity through temporal separation of functions rather than permanent parallel operation.
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 reliable detection of functional failures in high-frequency units, reducing the risk of inaccurate measurements and ensuring compliance with safety standards by automating the diagnosis process.
Implementation Method 1
a high-frequency source, by means of which high-frequency signals can be generated and transmitted towards the filling material and can be received as received signals after reflection at the filling material surface
Implementation Method 2
FMCW is based upon the fact that the high-frequency source transmits the high-frequency signal continuously, but at a modulated frequency. The change in frequency over time is linear by default for FMCW, and has a sawtooth or triangular shape.
Implementation Method 3
the receiver in turn generates the time-prolonged evaluation signal by mixing the corresponding electrical HF signals
Implementation Method 4
high-frequency signals are emitted in a pulsed manner at a defined clock speed in the direction of the filling material by means of a high-frequency source. Based upon this, the transit time up until the arrival of the high-frequency pulses reflected at the filling material surface is measured
Data Source
AI summary
A radar-based, fill-level measurement device for measuring a fill-level of a filling material in a container, the high-frequency unit of which can be checked with regard to its functionality, is designed redundantly and thus comprises two, activatable, high-frequency sources for generating the high-frequency signal and two, activatable receivers for sampling the received signal such that a time-prolonged evaluation signal is generated. As a result, a correspondingly designed diagnosis unit can switch between the active high-frequency source and/or between the active receiver, wherein before and after the switching, a defined property of the evaluation signal, such as a signal amplitude, is ascertained. If the defined property of the evaluation signal changes at least by a defined value as a result of the switching, the high-frequency unit is classified as not functional.