Optoelectronic Sensor Digital Correlation for Distance Measurement
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Solution Overview
Problem
Existing optoelectronic sensors face challenges in accurately determining distance with poor signal-to-noise ratios and are sensitive to interference from ambient light and other sources, leading to inaccurate measurements and spatial constraints due to their size and complexity.
Innovation Solution
A compact optoelectronic sensor design that emits multiple light pulses and evaluates them statistically, using a combination of analog and digital components to preprocess signals into a robust bipolar signal, allowing for precise distance measurement regardless of reflection and ambient light conditions, with a digital delay circuit for precise timing and an evaluation unit that determines the time of flight with high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an analog mixer is used to correlate reference and reception patterns, then distance measurement can be performed, but measurement precision deteriorates due to poor signal-to-noise ratio and interference from ambient light
Solution Approach 1:
The patent replaces the analog mixer with a digital correlation evaluation system. The light receiver's output signal is digitized and processed through a delay circuit that introduces precise time delays, allowing digital correlation between reference and reception patterns. This substitution of analog components with digital processing significantly improves signal-to-noise ratio handling and reception time determination precision, directly resolving the contradiction between measurement reliability and precision.
Solution Approach 2:
The patent implements a delay circuit that pre-processes the reception signal by introducing controlled time delays before correlation evaluation. By preliminarily adjusting the timing of the reception pattern to match expected transit times, the system optimizes the correlation process and improves measurement precision in the presence of noise and interference.
2Measurement precision
If multiple components are used for signal processing, then measurement accuracy can be maintained, but device complexity increases leading to larger size
Solution Approach 1:
The patent combines multiple signal processing functions into a single integrated sensor device. The light receiver, delay circuit, and correlation evaluation unit are merged into one compact system, eliminating the need for separate analog mixers and reducing overall device complexity while maintaining measurement precision through digital processing.
Solution Approach 2:
By replacing complex analog signal processing components with digital circuits, the patent reduces device complexity and size while maintaining or improving measurement accuracy. The digital correlation evaluation requires fewer physical components than traditional analog mixing systems.
3Measurement precision
If the sensor is designed for high precision measurement, then distance accuracy improves, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive analog mixing components with digital signal processing circuits that can be implemented using standard digital logic components or integrated circuits. This substitution maintains high measurement precision while significantly reducing manufacturing costs through the use of readily available digital components and simplified assembly processes.
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
Enables precise and robust distance measurement with improved accuracy and reduced interference sensitivity, allowing for compact and cost-effective implementation in spatially constrained environments.
Implementation Method 1
a light transmitter (16) for sending out individual light pulses
Implementation Method 2
the light reflected by the object is received
Implementation Method 3
a light receiver (16) for receiving the light pulses
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The opto-electronic sensor (10) has a light transmitter (12) for transmitting multiple individual light pulses successively. A light receiver (16) is provided, which receives the reflected or remitted individual light pulses. An analog preprocessor (28) is provided, which convert the individual light pulses received in the light receiver to a bipolar preprocessed signal and is supplied to a digital analysis unit over an analog to digital converter. The digital elements of the sensor are implemented on a digital component, like a Field-programmable gate array. An independent claim is also included for a method for measuring a distance or a distance change of a light propagation time of a light pulse.