Liquid Tilt Sensor with Averaged Optical Pattern Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional tilt detecting devices face challenges in accurately detecting tilt and horizontality, especially under low-temperature environments and varying photodetection conditions, due to viscosity changes in liquids and sensitivity limitations of air bubbles, leading to deteriorated performance and offset issues.

Innovation Solution

A tilt detecting device comprising a light source, a liquid component with a free liquid surface, a photodetection element, and an arithmetic processing unit that scans and averages photodetection signals to calculate the barycentric position of patterns, using alcohol with low viscosity and scanning around a barycenter with different radii to improve accuracy and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If oil with viscosity is used in the tilt sensor, then the absolute pattern can be stably recognized under vibrating conditions, but the follow-up properties deteriorate under low-temperature environments

Engineering Contradiction:

Improvestability of absolute pattern recognitionVSAvoidfollow-up properties under low temperature

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent changes the physical parameter of the liquid from high viscosity (oil) to low viscosity (alcohol) to maintain good follow-up properties at low temperatures while still achieving vibration resistance through a different mechanism (multiple pattern averaging)

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses multiple copies of the absolute pattern (at least three patterns) and averages their detection signals to obtain the tilt information, replacing the single pattern approach that relied on viscous damping

Inventive Principle:

Principle #26Copying

2Ease of operation

If air bubbles are used in the bubble tube, then the liquid can have low viscosity, but the movement of air bubbles is limited by glass inner surface accuracy and temperature deformation

Engineering Contradiction:

Improveliquid flow responsivenessVSAvoidtilt detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent extracts and eliminates the air bubbles from the system, using only the liquid medium with projected patterns, thereby removing the source of temperature deformation and glass surface accuracy issues while maintaining liquid responsiveness

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical bubble movement mechanism with an optical detection mechanism that projects patterns onto the liquid surface and detects reflections, eliminating dependence on glass inner surface accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If a single absolute pattern is projected to the liquid surface, then the tilt detection can be performed, but the detection is affected by photodetection condition variations and pixel responsiveness differences

Engineering Contradiction:

Improvetilt detection speedVSAvoidtilt detection accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides the single pattern detection into multiple pattern detections (at least three patterns), scanning different regions of the photodetection element and averaging the results to reduce the impact of pixel responsiveness variations and photodetection condition changes

Inventive Principle:

Principle #1Segmentation

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

The device stably detects tilt and horizontality without environmental temperature or photodetection condition effects, maintaining follow-up properties even at low temperatures and reducing errors from pixel responsiveness differences.

Implementation Method 1

a liquid component having a free liquid surface and for rear-surface reflecting by the free liquid surface

Methodology Applied

Scientific EffectRear-surface reflection: Reflection

Implementation Method 2

a photodetection element for photodetecting a reflection image of the rear-surface reflected pattern

Methodology Applied

Scientific EffectPhotodetection: Photoelectric Effect

Data Source

PatentUS10088310B2Tilt detecting device

Publication Date: 2018.10.02 TOPCON CORPORATION

AI summary

A tilt detecting device comprising, a light source for projecting a pattern, a liquid component having a free liquid surface and for rear-surface reflecting by the free liquid surface, a photodetection element for photodetecting a reflection image of the rear-surface reflected pattern, and an arithmetic processing unit, wherein the arithmetic processing unit is adapted to scan a predetermined range of a photodetection surface of the photodetection element as many times as required and performs averaging processing to a photodetection signal as detected and calculates a barycentric position of the pattern based on signals subjected to averaging processing.