Instrument Height Measurement Using Dual Light Paths in Surveying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surveying instruments with distance-measuring devices require a large-sized shutter and driving unit, limiting compactness and causing measurement interruptions during path switching.
Innovation Solution
The instrument height measuring unit employs two light receiving units to receive reference and distance-measuring light separately, eliminating the need for a shutter and enabling continuous measurements using the Time-of-Flight method, with visible laser light for centering and equivalent temperature characteristics for accurate signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a shutter and driving unit are used to switch between reference light path and distance-measuring light path, then light path switching is achieved, but the device size increases and measurement interruptions occur during switching
Solution Approach 1:
The patent divides the light receiving function into two separate light receiving units: one dedicated to receiving reference light and another dedicated to receiving distance-measuring light. This segmentation eliminates the need for a shutter to switch between light paths, as each receiver continuously receives its designated light type. The reference light receiving unit and distance-measuring light receiving unit operate independently and simultaneously, resolving the contradiction between achieving light path switching and maintaining compact device size without measurement interruptions.
2Ease of operation
If a shutter is used to alternatively emit reference light and distance-measuring light, then light path control is achieved, but measurement continuity is interrupted during switching
Solution Approach 1:
The patent implements continuous measurement by using two light receiving units that operate simultaneously and continuously. The first light receiving unit continuously receives reference light while the second light receiving unit continuously receives distance-measuring light reflected from the target. This eliminates the measurement interruptions that occur with shutter-based switching, as both light paths are actively monitored at all times without requiring periodic switching between them.
3Ease of operation
If a movable switching plate is used to block and allow light paths, then light path switching is achieved, but the device becomes large and requires additional driving mechanisms
Solution Approach 1:
The patent replaces the mechanical shutter system with a stationary optical configuration using two fixed light receiving units. Instead of using a movable switching plate that requires mechanical driving mechanisms to block and allow light paths, the system uses two stationary receivers positioned to simultaneously receive reference light and distance-measuring light through a beam splitter. This substitution of mechanical switching with a stationary optical receiving system eliminates the need for moving parts, reducing device size and simplifying manufacturing while maintaining light path control functionality.
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
A compact surveying instrument is achieved with continuous measurement capabilities and efficient centering, reducing the size and complexity of the instrument height measuring unit while maintaining high accuracy.
Implementation Method 1
a beam splitter configured to be incident with light emitted from the light transmitting unit, split the incident light into reference light and distance-measuring light
Implementation Method 2
a first light receiving unit configured to receive the reference light, a second light receiving unit configured to receive light being the distance-measuring light
Implementation Method 3
make a distance measurement by irradiating light toward a position below a vertical axis of a surveying instrument main body and calculate an instrument height
Data Source
AI summary
In a surveying instrument including an instrument height measuring unit the instrument height measuring unit includes a light transmitting unit configured to emit light, a beam splitter configured to be incident with light emitted from the light transmitting unit, split the incident light into reference light and distance-measuring light, send the reference light to a reference light path, and send the distance-measuring light to a distance-measuring light path, a first light receiving unit configured to receive the reference light, a second light receiving unit configured to receive light being the distance-measuring light that has been emitted toward a position below the vertical axis of the surveying instrument main body and returned by being reflected by a distance-measuring object, and an arithmetic unit configured to calculate the instrument height based on a difference between light reception signals generated by the first light receiving unit and the second light receiving unit.