Multi-Transmitter Optical Distance Sensor Using Transit Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical distance-measuring devices for surveillance areas face challenges such as high manufacturing costs, reduced accuracy with increased range, susceptibility to interference, and complex mechanical systems, particularly in phase correlation methods.
Innovation Solution
The device employs a solid angle with multiple transmitters arranged to illuminate distinguishable light spots on objects, using real transit time measurements instead of phase evaluation, and differentiating means to distinguish between reflected pulses from different transmitters, allowing for high-quality individual measurements and scalable configurations without moving parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase correlation method is used with modulated light source, then distance measurement capability is achieved, but manufacturing costs increase due to required optical bandpass filters
Solution Approach 1:
The patent extracts and removes the expensive optical bandpass filter from the system by switching to a different measurement principle (transit time measurement) that does not require spectral filtering, thereby eliminating the manufacturing cost while preserving distance measurement capability
Solution Approach 2:
The patent replaces the optical filtering mechanism (mechanical/optical system) with a temporal discrimination mechanism (electronic timing system), substituting a complex optical filtering system with a simpler electronic time-difference measurement system
2Measurement precision
If multiple transmitters are used to increase measurement coverage, then spatial resolution improves, but susceptibility to interference from extraneous light increases
Solution Approach 1:
The patent applies preliminary timing markers to each transmitted light pulse, allowing the receiver to pre-identify and filter signals based on their expected arrival times, thereby distinguishing valid signals from extraneous light interference before processing
Solution Approach 2:
The system uses feedback through time-correlation analysis where the receiver compares the timing of received pulses with the known transmission schedule, continuously adjusting and identifying valid signals based on temporal patterns while rejecting random extraneous light
3Loss of information
If mechanically moved systems like laser scanners are used to obtain three-dimensional location information, then measurement completeness improves, but device complexity and mechanical susceptibility increase
Solution Approach 1:
The patent replaces mechanical scanning systems with a static multi-transmitter array that uses electronic control and time-difference measurement to achieve three-dimensional location information, eliminating moving parts while maintaining measurement completeness
Solution Approach 2:
The patent adds the time dimension as a measurement parameter, using time-difference of arrival from multiple transmitters to encode spatial information, thereby achieving 3D location without mechanical movement by utilizing temporal information
4Measurement precision
If modulation wavelength is decreased to increase accuracy, then distance resolution improves, but maximum measurement range decreases
Solution Approach 1:
The patent changes the measurement parameter from optical wavelength to temporal duration, using the transit time of light pulses rather than phase modulation wavelength, thereby decoupling measurement precision from wavelength constraints and enabling both high resolution and long range
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 provides high availability and interference immunity, enabling precise distance determination with high spatial resolution and flexibility, reducing costs and mechanical complexity while maintaining accuracy across varying distances.
Implementation Method 1
Distance-measuring optical sensors, in which the transit time of a light pulse is evaluated to determine a distance of an object from the optical sensor
Implementation Method 2
A solid angle into which the transmitters radiate is so small and the transmitters are arranged in the transmitter unit in such a way that the transmitted light pulses of the various transmitters illuminate light spots that can be distinguished from one another on an object in the monitoring area
Implementation Method 3
distinguishing means are present in order to distinguish between reflected light pulses that are based on transmitted light pulses from different transmitters
Data Source
Figure 1
AI summary
The invention relates to a device for optically determining distances to objects in a monitoring area, comprising a transmitter unit with a plurality of transmitters for emitting light pulses into the monitoring area, a detector unit with at least one detector for detecting light pulses reflected from the monitoring area, and a control and evaluation unit for controlling the transmitter unit and for evaluating measurement data from the detector unit.The device is characterized in that the solid angle into which the transmitters emit light is so small, and the transmitters are arranged in the transmitting unit such that the transmitted light pulses of the different transmitters illuminate distinguishable spots of light on an object in the monitoring area; that distinguishing means are provided to differentiate reflected light pulses originating from transmitted light pulses of different transmitters; and that the evaluation and control unit is configured to determine, from the time differences between the reception times of the reflected light pulses and the transmission times of the corresponding transmitted light pulses, as well as the speed of light in the monitoring area, the distances of object areas illuminated by the transmitted light pulses relative to the detector unit. The invention also relates to a method for optically determining distances to objects in a monitoring area.