Gravity Gradiometer Sensor Mass Balancing Circuit

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing gravity gradiometers face challenges in accurately measuring diagonal and off-diagonal components of the gravitational gradient tensor, particularly when in motion, due to difficulties in distinguishing spatial variations from temporal fluctuations, and require precise balancing of sensor masses for operation.

Innovation Solution

A gravity gradiometer design incorporating a capacitor plate concentric with a sensing coil, forming a capacitor used in a balancing circuit, allows for precise adjustment and measurement of sensor mass balance, ensuring accurate measurements of the gravity gradient components by maintaining consistent gap spacing during both balancing and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a capacitor plate is positioned close to the sensing coil for balancing circuit operation, then the balancing precision is improved, but the risk of electrical interference and signal distortion increases

Engineering Contradiction:
Improvebalancing precisionVSAvoidelectrical interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

An insulating structure is introduced as an intermediary element between the capacitor plate and the sensing coil. This insulator maintains the electrically isolated close spacing required for precise balancing while preventing direct electrical interference. The insulator acts as a mediator that allows the beneficial close proximity for capacitance while blocking the harmful electrical coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The space between the capacitor plate and sensing coil is segmented into distinct functional zones: the capacitor plate region, the insulating barrier region, and the sensing coil region. This segmentation allows each component to operate in its optimal environment while maintaining the necessary close proximity for high-precision balancing without direct interference.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the gradiometer is used in airborne conditions with motion, then the versatility and applicability are improved, but the measurement accuracy deteriorates due to temporal fluctuations

Engineering Contradiction:
Improveairborne applicabilityVSAvoidmeasurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The sensor mass balancing is performed in advance using the capacitor plate and sensing coil arrangement before airborne operation begins. This preliminary balancing action ensures that the sensor mass is optimally positioned to minimize sensitivity to temporal fluctuations, allowing accurate gravity gradient measurements even during airborne motion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The capacitor plate-sensing coil arrangement provides a feedback mechanism for monitoring and adjusting sensor mass balance. During airborne operation, this feedback system continuously ensures that the sensor mass remains properly balanced despite vibrations and motions, maintaining measurement accuracy while enabling versatile airborne application.

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 design enhances the accuracy and precision of gravity gradient measurements by enabling effective balancing and operation of the gradiometer, even in airborne conditions, by using a concentric capacitor plate and coil arrangement that sees the same signal environment, thus improving the detection of subtle gravitational variations.

Implementation Method 1

a capacitor plate having a concentric arrangement with the sensing coil for providing one plate of a capacitor used in a balancing circuit for measuring the balance of the sensor mass

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a transducer for measuring the movement of the sensor mass, the transducer having a sensing coil mounted on a mount element and located adjacent the sensor mass

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

at least one sensor mass for movement in response to at least one component of the gravity gradient tensor

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP1949142B1Gravity gradiometer
Publication Date: 2015.05.13 TECHNOLOGICAL RESOURCES PTY LTD
  • EP1949142B1 patent drawingFigure 1~2
  • EP1949142B1 patent drawingFigure 3~4
  • EP1949142B1 patent drawingFigure 5~7

AI summary

A gravity gradiometer is described which comprises a pair of sensor bars (41, 43) arranged in housings (45, 47). Transducers (71) are arranged adjacent the bars (41, 43) for measuring movement of the bars in response to the gravity gradient tensor. At least one of the transducers has a sensing coil (510) and a capacitor plate (518a) having a concentric arrangement with the sensing coil (510) for providing one plate of a capacitor used in a balancing circuit for measuring the balance of the sensor mass.