Triangulation Sensor Distance Calculation Using Light Spot Shape
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Solution Overview
Problem
Existing triangulation sensors face challenges in achieving precise and reliable distance determination due to limitations in position resolution, dynamic range, and sensitivity, especially under varying ambient light conditions, and require expensive optics to meet these requirements.
Innovation Solution
The solution involves using intrafocal tilting of the light receiver to increase the distance dependency of light spot shape, combining position and shape evaluation for distance determination, and employing a weighted mean calculation to enhance accuracy, while reducing dynamic requirements on the light receiver by ensuring consistent light energy across distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the Scheimpflug rule is used to image the light spot sharply on the light receiver, then position determination precision is improved, but the dynamic range and sensitivity requirements become excessively high
Solution Approach 1:
The patent transitions from evaluating only the one-dimensional position of the light spot to evaluating both position and shape (size/diameter) dimensions. By measuring the diameter of the light spot in addition to its position, the system gains an additional degree of freedom for distance determination, allowing it to operate without strict adherence to the Scheimpflug rule while maintaining measurement precision.
Solution Approach 2:
The patent changes the evaluation parameters from solely position-based to include both position and shape (diameter) parameters. This parameter expansion allows the system to determine distance through multiple features, reducing the need for high dynamic range and sensitivity while maintaining or improving measurement accuracy.
2Reliability
If redundant computing units are used to determine the light center of gravity, then reliability of distance determination is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces shape (diameter) as an additional evaluation dimension alongside position. This provides a second independent method for distance determination without requiring redundant computing units, achieving reliability through diversity of measurement approaches rather than redundancy of hardware.
Solution Approach 2:
The patent creates a complementary measurement approach by evaluating light spot shape, which serves as an alternative verification method to position-based measurement. This copying of the measurement function through a different physical feature (diameter instead of position) provides reliability without duplicating the entire computing system.
3Measurement precision
If expensive imaging optics are used to fulfill the Scheimpflug rule, then position resolution is improved, but cost increases
Solution Approach 1:
The patent evaluates both position and shape dimensions of the light spot, providing two independent distance determination methods. This dimensional expansion allows the system to achieve high position resolution without requiring expensive imaging optics that strictly fulfill the Scheimpflug rule, as the shape measurement provides complementary information.
Solution Approach 2:
The patent employs a simpler optical configuration that does not require expensive, precision-engineered imaging optics. By using a more straightforward optical setup combined with dual parameter evaluation (position and shape), the system achieves comparable or superior performance at lower cost.
4Adaptability or versatility
If the light receiver is arranged to meet high dynamics, high sensitivity and low costs, then these requirements cannot be met simultaneously
Solution Approach 1:
The patent measures both position and shape (diameter) of the light spot, providing two independent distance determination channels. This dimensional expansion allows the light receiver to operate with relaxed dynamic range and sensitivity requirements, as each measurement dimension can be optimized independently and their results combined for reliable distance determination.
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 results in a more accurate, reliable, and cost-effective distance determination method that simplifies the distance calculation by leveraging the shape and position of light spots, reducing the need for expensive optics and improving the sensor's dynamic range.
Implementation Method 1
A light transmitter sends out light which, after reflection on an object, is evaluated in a spatially resolving receiver
Implementation Method 2
The light receiver (18) is arranged intrafocally, that is to say lies in the focal plane of the receiving optics (20)
Data Source
Figure 1~2
Figure 3
AI summary
The opto-electronic sensor (10) has a light transmitter (16) and a local resolution opto-receiver (18) for receiving an object (12,12'). An examining unit (21) is formed for determining distance of the object, particularly a diameter of a light spot on the opto-receiver. An independent claim is also included for a method for the collection and determining the distance of an object in a monitored area.