Optoelectronic Sensor Adaptive Gain Control for Short-Range Detection
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Solution Overview
Problem
Asynchronous optoelectronic sensors face reduced sensitivity at short distances and are prone to false positives due to the need for increased electromagnetic radiation and interference from other sources, with existing solutions either introducing noise or increasing complexity.
Innovation Solution
The optoelectronic sensor employs a periodic pulsed electromagnetic radiation with varying amplitudes and a regulation element to adjust the amplification stage's gain in discrete zones, allowing for continuous sensitivity modulation without discontinuity, even at short distances, by selecting the appropriate pulse for detection based on the zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the distance between emitter and receiver is reduced, then the sensor can detect objects at closer ranges, but the sensitivity is reduced and false positives increase
Solution Approach 1:
The patent applies dynamics by making the amplification gain adjustable and adaptive rather than fixed. The system dynamically changes the gain level based on the detected distance between emitter and receiver, allowing optimal sensitivity at each distance point. This resolves the contradiction by enabling the system to adapt its sensitivity characteristics to match the operating distance.
Solution Approach 2:
The patent changes the amplification gain parameter as a function of distance. By regulating the gain according to the detected distance, the system maintains appropriate sensitivity across different operating ranges. This parameter adjustment resolves the contradiction between reduced distance and maintained sensitivity.
2Measurement precision
If amplification gain is increased to maintain sensitivity at short distances, then sensitivity is improved, but noise and false positives increase
Solution Approach 1:
The system dynamically adjusts the amplification gain based on distance feedback, increasing gain only when needed for distant objects and reducing it for close objects. This dynamic adaptation prevents excessive noise amplification while maintaining sensitivity when required, resolving the contradiction between sensitivity and noise.
Solution Approach 2:
The system uses feedback from distance detection to regulate the amplification gain. The detected distance informs the appropriate gain level, creating a closed-loop control that prevents excessive amplification and associated noise while ensuring sufficient sensitivity at appropriate distances.
3Measurement precision
If a regulation element with continuous gain control is used, then sensitivity can be optimized for each distance, but device complexity increases
Solution Approach 1:
The patent segments the continuous gain regulation into discrete steps or zones corresponding to different distance ranges. This segmentation simplifies the regulation element while maintaining the ability to optimize sensitivity for different distances, resolving the contradiction between optimization capability and device complexity.
Solution Approach 2:
The system changes the amplification gain parameter in discrete steps rather than continuously, simplifying the regulation element's complexity while still providing sufficient sensitivity optimization across different operating distances.
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 configuration maintains high sensitivity across varying distances without excessive noise or complexity, enabling accurate object detection by varying the pulse amplitude effectively, even at short distances where traditional sensors would be less sensitive.
Implementation Method 1
a photodetector arranged for transforming the electromagnetic radiation received into a received electrical signal
Data Source
Figure 1~2
Figure 3~4b
Figure 5
AI summary
The present invention relates to an optoelectronic sensor (1) including: o a receiver (3) arranged for receiving an electromagnetic radiation, the receiver (3) comprising a photodetector (5) arranged for transforming the electromagnetic radiation received into a received electrical signal and an amplification stage (6) having variable gain between a minimum gain and a maximum gain that can amplify said received electrical signal; o an emitter (2) arranged for emitting a periodic electromagnetic radiation including a pulse train in each period, each pulse train including n pulses, where n ≥ 2, and wherein each jth pulse with j = 1,....,n of the train having an amplitude equal to: Aj=Aj−1*B where B is an integer greater than 0 with B ≤ D where D = (maximum gain of the amplification stage/minimum gain of the amplification stage); o a regulation element (7) configured for the regulation of the gain of the amplification stage (6) of the receiver having a regulation range subdivided into a number n of consecutive zones (11; 12) equal to the number n of pulses of the pulse train emitted by the emitter (2), the first zone (11) related to distances between emitter (2) and receiver (3) starting from a minimum distance possible for using the optoelectronic sensor (1) and the n-th zone (12) related to distances between emitter (2) and receiver (3) terminating with a maximum distance possible for using the optoelectronic sensor (1); said gain of said amplification stage (6) being selected by selecting a point in the zone (11; 12) of said regulation range of the regulation element (7); said regulation range being produced in such a way that in each zone j ≠ n of the regulation range, moving a point selected within said regulation element (7) inside the j-th zone in the direction from the starting point adjacent to the (j-1)th zone toward the endpoint adjacent to the zone (j+1)th, the corresponding gain set up in the amplification stage (6) is moved from the minimum gain that can be set up in the amplification stage (6) to the minimum gain that can be set up in the amplification stage (6) multiplied by the whole number B equal to the ratio of the amplitude between two consecutive pulses in a same pulse train.