Optoelectronic Sensor Distance Measurement Amplitude Error Correction
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Solution Overview
Problem
Conventional distance measurement methods using optoelectronic sensors face challenges with varying object reflectivities, leading to amplitude errors and insufficient dynamic range, particularly when dealing with high and low reflectivity objects, which results in inaccurate time-of-flight measurements due to overloading and noise in receiver units.
Innovation Solution
The method involves emitting light pulses with at least two different pulse energies and using the difference in reception times to correct for amplitude errors, focusing on the rising edge of the pulses to improve accuracy and dynamic range, eliminating temperature dependencies and multiple reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single pulse energy is used for distance measurement, then the device complexity is low, but the measurement precision deteriorates due to amplitude errors from varying object reflectivities
Solution Approach 1:
The transmitter unit emits light pulses with alternating high and low energies in periodic succession. This periodic action allows the system to acquire multiple reception time measurements with different pulse energies, enabling amplitude error correction through comparison of the measurements while maintaining relatively simple device control logic.
Solution Approach 2:
The system changes the pulse energy parameter of the transmitted light pulses between high and low values. By measuring reception times for at least two different pulse energies and using the difference to correct amplitude errors, the system improves distance measurement accuracy without requiring complex additional hardware.
2Adaptability or versatility
If the receiver unit is designed to cover a wide dynamic range to handle objects with greatly differing reflectivities, then the adaptability improves, but the reliability deteriorates due to overloading with high echo amplitudes
Solution Approach 1:
Instead of designing the receiver to handle the full dynamic range of all possible reflectivities, the system uses partial action by transmitting pulses at two specific energy levels. This allows the receiver to operate within a limited, safe dynamic range while still achieving wide adaptability through the alternating pulse energies and amplitude error correction method.
Solution Approach 2:
The system uses feedback by comparing reception time measurements from pulses with different energies. The difference between these measurements provides information about amplitude errors, which is then used to correct the distance calculation. This feedback mechanism enables reliable measurements across a wide dynamic range without overloading the receiver.
3Measurement precision
If conventional amplitude compensation methods are used, then the measurement precision improves for single amplitude conditions, but the adaptability deteriorates when dealing with varying object reflectivities and temperature conditions
Solution Approach 1:
The alternating pulse energy method serves multiple functions simultaneously: it provides amplitude error correction, compensates for temperature dependencies, and handles varying object reflectivities. By measuring reception times with at least two different pulse energies and using the difference to correct errors, the system achieves universal applicability across diverse measurement conditions without requiring separate compensation mechanisms.
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 significantly enhances the accuracy of distance measurements by providing high-quality data with reduced noise and temperature influence, allowing for precise correction of amplitude errors across a wide dynamic range without overloading the receiver.
Implementation Method 1
a transmitter unit emits light pulses into a detection area, a receiver unit detects light pulses reflected back from an object to be measured
Implementation Method 2
light pulses reflected back from an object to be measured in the detection area
Implementation Method 3
a distance of the object is determined from a time difference between the time at which a light pulse is received and the time at which this light pulse is emitted
Data Source
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AI summary
The invention relates to a method for measuring the distance of objects, in which the following steps are performed: a transmitting unit emits light pulses, a receiving unit detects light pulses reflected back from an object to be measured, and the distance of the object is determined from the time difference between the time of reception of a light pulse and the time of transmission of that light pulse. According to the invention, this method is further developed in that light pulses with at least two different pulse energies are emitted and that, depending on the differences between the measured times of reception for the different pulse energies, the times of reception are corrected with a correction value. The invention also relates to an optoelectronic sensor.