Sensor Gimbal Flex Routing for Borehole Bias Correction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In borehole surveying, it is challenging to remove systematic bias from sensor measurements, especially for sensors with sensitive axes aligned along the borehole, due to mechanical limitations.

Innovation Solution

A sensor gimbal system with a rotating sensor gimbal and a flex circuit routed on a curved path to reduce signal distortion, combined with shielding and a silicon adhesive to isolate vibrations, allows for bias correction by rotating the sensor sensitive axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sensor is rotated to remove systematic bias, then measurement precision is improved, but signal distortion and kinking occur due to flex circuit routing

Engineering Contradiction:

Improvebias correctionVSAvoidsignal distortion

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The flex circuit is routed along a curved path that matches the rotational arc of the sensor gimbal, allowing the circuit to flex smoothly during rotation without creating sharp bends or kinks that would distort signals. This curved routing enables the sensor to rotate through multiple positions for bias correction while maintaining signal integrity.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Measurement precision

If the sensor gimbal is rotated to measure bias in all attitudes, then measurement precision is improved, but vibrations and stresses are introduced to the sensor

Engineering Contradiction:

Improvebias measurementVSAvoidvibrations and stresses

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

Vibration isolation elements are pre-installed between the sensor and the rotating gimbal structure to cushion against vibrations and stresses generated during rotation. This prior cushioning protects the sensitive sensor from mechanical disturbances while allowing the gimbal to rotate through its full range of motion for comprehensive bias measurement.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the flex circuit is routed straight for simplicity, then device complexity is reduced, but signal distortion occurs during rotation

Engineering Contradiction:

Improveflex circuit routingVSAvoidsignal distortion

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

Instead of a straight routing, the flex circuit follows a curved path that accommodates the rotational movement of the sensor gimbal. This curved routing adds some complexity to the circuit layout but prevents signal distortion by avoiding sharp bends and excessive flexing during rotation.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Strength

If the sensor is firmly mounted to the gimbal, then structural strength is improved, but vibrations are transmitted to the sensor

Engineering Contradiction:

Improvesensor mountingVSAvoidvibrations

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

Vibration isolation elements are incorporated into the sensor mounting structure to decouple the sensor from the rotating gimbal frame. These elements provide mechanical support while filtering out vibrations and stresses generated during rotation, allowing the sensor to remain firmly mounted yet isolated from harmful mechanical disturbances.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS12305499B2Survey instrument

Publication Date: 2025.05.20 REFLEX INSTRUMENTS ASIA PACIFIC PTY LTD

AI summary

A sensor gimbal system employs one sensor gimbal on which a sensor is mounted. The sensor gimbal is configured to orient a sensitive axis of the sensor with respect to a survey instrument. A sensor motor assembly is configured to rotate the sensor gimbal between a first hard stops and a second hard stop. A dowel pin extends from the mating bevel gear to engage the hard stops. A flex circuit has a flex cable from a sensor PCB, on which the sensor is mounted, to an electronic circuit board.