Pulsed Radar Level Gauge Harmonic Regulation

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Solution Overview

Problem

Current pulsed radar level gauge systems face challenges in achieving fast and accurate oscillator regulation due to low frequency differences between transmission and reference signals, leading to slow response to frequency disturbances and increased power consumption when increasing oscillator frequencies.

Innovation Solution

The system employs frequency selection circuitries to extract higher order harmonic frequency components of transmission and reference signals, allowing for faster regulation of the reference signal's pulse repetition frequency without increasing power consumption, using harmonics filters to filter out intended harmonic frequency components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the oscillator frequency is increased to provide a higher frequency difference signal for faster regulation, then the response speed of oscillator regulation is improved, but the power consumption increases

Engineering Contradiction:
Improveresponse speed of oscillator regulationVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies the principle of using higher order harmonic frequency components (which are like higher frequency vibrations) to achieve faster regulation. By extracting and utilizing harmonic components at N times the fundamental frequency, the system can regulate the oscillator frequency N times faster without actually increasing the fundamental oscillator frequency, thus avoiding the power consumption penalty.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the parameter used for frequency difference from the fundamental frequency to higher order harmonic frequency components. This parameter change allows the system to achieve faster regulation (N times faster for Nth harmonic) while maintaining the same fundamental oscillator frequency and power consumption level.

Inventive Principle:
Principle #35Parameter changes

2Speed

If the frequency difference between transmission and reference signals is increased to improve regulation speed, then the response to frequency disturbances is improved, but the oscillator regulation cannot control faster disturbances effectively

Engineering Contradiction:
Improveregulation speedVSAvoidcontrol accuracy for fast disturbances
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent uses higher order harmonic frequency components to create a frequency difference signal at N times the fundamental frequency. This allows the system to detect and respond to frequency disturbances N times faster, improving both regulation speed and the ability to control fast disturbances effectively.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent implements a feedback mechanism where the higher order harmonic frequency components are continuously monitored and used to adjust the oscillator frequency. This feedback loop enables real-time correction of frequency disturbances at a much faster rate, improving reliability for fast-changing conditions.

Inventive Principle:
Principle #23Feedback

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 enables faster and more accurate regulation of the reference signal, reducing start-up time and maintaining low energy consumption, making it suitable for battery-powered applications like wireless radar level gauges.

Implementation Method 1

first frequency selection circuitry arranged between the first pulse generating circuitry and the frequency control circuitry and configured to provide a higher order harmonic frequency component of the transmission signal to the frequency control circuitry; and second frequency selection circuitry arranged between the second pulse generating circuitry and the frequency control circuitry and configured to provide a higher order harmonic frequency component of the reference signal to the frequency control circuitry

Methodology Applied
Scientific EffectHarmonic frequency component extraction:

Implementation Method 2

a propagation device connected to the first pulse generating circuitry and arranged to propagate the transmission signal towards a surface of the product inside the tank, and to return a reflected signal resulting from reflection of the transmission signal at the surface of the product contained in the tank

Methodology Applied
Scientific EffectElectromagnetic signal propagation:

Implementation Method 3

return a reflected signal resulting from reflection of the transmission signal at the surface of the product contained in the tank

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 4

the measurement circuitry being configured to form a measurement signal based on the reflected signal and the reference signal

Methodology Applied
Scientific EffectTime correlation:

Implementation Method 5

frequency control circuitry for controlling the second pulse generating circuitry to generate said second pulse train with a second pulse repetition frequency, the second pulse repetition frequency differing from the first pulse repetition frequency by a predetermined frequency difference

Methodology Applied
Scientific EffectFrequency modulation: Phase Modulation

Data Source

PatentEP2702372B1Pulsed radar level gauge system with higher order harmonic regulation
Publication Date: 2015.06.17 ROSEMOUNT TANK RADAR
  • EP2702372B1 patent drawingFigure 1~2
  • EP2702372B1 patent drawingFigure 3
  • EP2702372B1 patent drawingFigure 4

AI summary

A radar level gauge system comprising first pulse generating circuitry for generating a transmission signal, second pulse generating circuitry for generating a reference signal; and frequency control circuitry for controlling the second pulse generating circuitry to achieve a predetermined frequency difference between the transmission signal and the reference signal. The radar level gauge system further comprises first frequency selection circuitry configured to provide a higher order harmonic frequency component of the transmission signal to the frequency control circuitry; and second frequency selection circuitry configured to provide a higher order harmonic frequency component of the reference signal to the frequency control circuitry. The frequency control circuitry is configured to control the second pulse generating circuitry based on the higher order harmonic frequency component of the transmission signal and the higher order harmonic frequency component of the reference signal. Hereby, improved regulation of the reference signal can be achieved substantially without any increase in power consumption of the radar level gauge system.