Radar Level Gauging Distance Approximation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radar level gauges using frequency modulated continuous wave (FMCW) technology are power hungry, making them unsuitable for applications with limited power sources, and require a large number of samples for accurate distance measurement, which is inefficient in terms of power consumption.
Innovation Solution
A radar level gauging system using a method with pulses of constant frequency, where a transmit signal is formed as a pulse train with each pulse being frequency modulated, and the received signal is processed in I and Q channels to provide intermediate frequency (IF) signals, filtered to obtain primary and secondary amplitude values, allowing for a rough distance approximation based on the relationship between these values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FMCW (frequency modulated continuous wave) is used for radar level gauging, then measurement precision is improved, but use of energy deteriorates (power consumption increases)
Solution Approach 1:
The patent applies periodic pulsed action instead of continuous wave transmission. The radar system transmits periodic pulses with duty cycles typically between 0.1% and 10%, which dramatically reduces average power consumption while maintaining measurement capability. Each pulse is followed by a listening period where the transmitter is turned off, allowing energy savings during non-measurement intervals.
Solution Approach 2:
The patent segments the continuous measurement process into discrete pulsed measurements. Instead of continuously transmitting and measuring, the system divides operation into distinct transmit pulses and receive intervals, enabling power management and reducing overall energy consumption while preserving essential measurement functionality.
2Measurement precision
If a large number of samples are taken for accurate distance measurement, then measurement precision is improved, but use of energy deteriorates (power consumption increases)
Solution Approach 1:
The patent implements adaptive sampling that takes only the necessary number of measurements rather than always using maximum samples. The system evaluates signal quality and noise conditions, then determines the minimum number of samples needed to achieve acceptable measurement precision, avoiding unnecessary energy expenditure from excessive sampling.
Solution Approach 2:
The system uses feedback mechanisms to monitor measurement quality and adjust sampling rates dynamically. When signal conditions are good, fewer samples are taken; when conditions deteriorate, sampling increases only as needed. This feedback-driven approach optimizes the balance between measurement accuracy and power consumption.
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 reduces power consumption and provides a reliable rough distance estimate, which can be used to improve the accuracy of distance measurement, while also serving as a verification for the accurate distance determination, thus enhancing the sensitivity and reliability of the measurement process.
Implementation Method 1
The transmitted signal is reflected by the surface of the contents in the tank (or by any other impedance transition) and an echo signal, which has been delayed a certain time, is returned to the gauge
Implementation Method 2
The echo signal is mixed with the transmitted signal to generate a mixer signal, having a frequency equal to the frequency change of the transmitted signal that has taken place during the time delay
Implementation Method 3
each pulse being frequency modulated around a defined center frequency
Data Source
AI summary
Level gauging including an approximation of a distance to the surface of a product kept in a tank. The approximation is determined by relating an amplitude of a first harmonic of an IF signal with an amplitude of a second harmonic of the IF signal.Basically, each harmonics represents a given distance range. By determining the received power in two or more harmonics, and correlating them to each other, the distance may be estimated. Depending on modulation and other parameters the distance dependence may be very different, and may be selected to suit the application.