Displacement Sensor Adaptive Gain Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional displacement sensors face challenges in adjusting sensitivity effectively when the intensity of reflected light significantly fluctuates, leading to unstable measurements and errors, particularly when detecting objects with different reflectance levels.
Innovation Solution
The displacement sensor employs a light receiving unit with multiple signal processing units applying different magnifications to the light receiving amount signal, allowing for selection of appropriate light receiving amount data for sensitivity adjustment based on a predetermined rule, ensuring consistent and stable measurements by correlating the selected data with a predetermined appropriate value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensitivity adjustment is performed based on the ratio between light receiving amount data and optimal value, then measurement precision can be maintained under stable conditions, but measurement precision deteriorates when reflected light intensity fluctuates significantly
Solution Approach 1:
The system dynamically switches between multiple signal processing units with different gain values based on the detected light receiving amount. When reflected light intensity changes, the system automatically selects an appropriate processing unit to maintain measurement precision, making the sensitivity adjustment mechanism adaptive rather than static.
Solution Approach 2:
The invention changes the gain parameter of the signal processing unit based on the light receiving amount. By selecting different gain values (first gain for high light amounts, second gain for low light amounts), the system adapts to varying reflectance conditions and maintains reliable measurements across different object types.
2Device complexity
If a single signal processing unit with fixed gain is used, then device complexity is reduced, but measurement precision deteriorates when light receiving amount varies
Solution Approach 1:
Instead of using a single fixed-gain processing unit, the system employs multiple processing units with different gain values and dynamically selects the appropriate one based on real-time light receiving amount conditions, achieving both structural simplicity and measurement precision.
Solution Approach 2:
Multiple signal processing units with different gain characteristics are integrated into a single system that can handle both high and low light receiving amount conditions, making the system universally applicable to various reflectance scenarios without requiring separate measurement systems.
3Adaptability or versatility
If sensitivity adjustment is performed frequently to adapt to changing objects, then adaptability improves, but loss of time increases due to repeated adjustment calculations
Solution Approach 1:
Multiple signal processing units with different gain values are prepared in advance before measurement begins. When measurement starts, the system simply selects the pre-prepared processing unit that matches the current light receiving amount condition, avoiding time-consuming real-time sensitivity adjustment calculations.
Solution Approach 2:
The system automatically selects the appropriate signal processing unit based on the detected light receiving amount without requiring external intervention or complex calculation. The pre-configured processing units serve themselves by being ready to handle different conditions, reducing the time burden on the control system.
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 prompt sensitivity adjustment, maintaining light receiving amount data in an appropriate state, even when the object changes, thereby ensuring accurate displacement measurements, especially for objects with varying reflectance and high-speed or small targets.
Implementation Method 1
receive reflected light from an object reflecting the light from the light projecting unit
Implementation Method 2
a light receiving element such as a PSD, a CCD, and a CMOS
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A signal processing unit (C1, C2, C3) for processing a light reception signal from an imaging element (12) at different magnifications is provided in a light receiving unit (102) in a displacement sensor (1). This sensor (1) measures a displacement by using light receiving amount data generated by the signal processing unit (C1) for each detection processing by a light projecting unit (101) and the light receiving unit (102), and further adjusts sensitivity for next detection processing. In sensitivity adjustment processing, when a peak value in the light receiving amount data generated by the signal processing unit (C1) approximates to 0, a peak value extracted by the signal processing unit (C2) to which higher magnification is applied is employed. Alternatively, when a peak value in the light receiving amount data generated by the signal processing unit (C1) is saturated, a peak value extracted by the signal processing unit (C3) to which 1-fold magnification is applied is employed.