Light Curtain Optical Units With Bidirectional Identifier Verification
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Solution Overview
Problem
Conventional safety light curtains face high fabrication costs and complexity due to distinct emitter and receiver units, and suffer from unidirectional optical communication, which can lead to erroneous synchronization and unsafe conditions when optical units are not properly paired.
Innovation Solution
The solution involves pairing optical units with unique identifiers during installation and continuous monitoring, using bidirectional communication via radiation beams to verify the identifiers, allowing for flexible and cost-effective modular architecture with transceiver units that can function as both emitters and receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If distinct emitter and receiver units are used, then the light curtain can provide dedicated transmission and reception functions, but the fabrication costs increase and device complexity increases
Solution Approach 1:
The patent applies multi-functionality by enabling optical units to serve both as transmitters and receivers. Each optical unit is equipped with both radiation emitters and radiation receivers, allowing it to perform multiple functions. This eliminates the need for separate dedicated emitter and receiver units, reducing fabrication costs and device complexity while maintaining reliable transmission and reception capabilities through bidirectional communication.
2Device complexity
If unidirectional optical communication is used, then the system architecture is simpler, but erroneous synchronization and unsafe conditions occur when optical units are not properly paired
Solution Approach 1:
The patent implements feedback through bidirectional optical communication where optical units exchange identification signals and verify pairing status. Each unit transmits its identifier and receives identifiers from opposing units, enabling verification of correct pairing. This feedback mechanism ensures accurate synchronization and prevents unsafe conditions by confirming that only properly paired units communicate, resolving the reliability issue without significantly increasing architectural complexity.
3Reliability
If bidirectional communication with identifier verification is implemented, then erroneous pairing is prevented and safety is enhanced, but device complexity and communication protocol complexity increase
Solution Approach 1:
The patent applies preliminary action by pre-assigning unique identification signals to each optical unit before deployment. During initialization, units exchange these pre-configured identifiers and verify pairing status before entering operational mode. This preliminary verification step ensures correct pairing is established in advance, preventing erroneous connections and enhancing safety without requiring complex real-time communication protocols during operation.
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 prevents erroneous pairing and synchronization issues, enhancing safety while reducing costs and complexity by using existing radiation beams for communication and allowing for flexible module configurations.
Implementation Method 1
Light curtains typically are employed for operator protection around machinery... Light curtains employing infrared or visible light beams... The LEDs transmit modulated infrared light beams along separate parallel channels to the PTs at the receiver bar
Implementation Method 2
phototransistors (PT), photodiodes or photoreceivers mounted along a receiver bar at the opposite side of the zone. The LEDs transmit modulated infrared light beams along separate parallel channels to the PTs at the receiver bar. If one or more beams are blocked from penetration by an opaque object
Data Source
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AI summary
The present invention relates to optical units which are part of a light curtain for monitoring a protective field, and to a method for monitoring the correct pairing of such optical units. The light curtain comprises at least one first and one second optical unit each comprising at least one radiation emitter and/or receiver for forming at least one radiation beam between the first and second optical unit. The first and second optical unit each comprises a controller unit and a communication interface. A unique identifier is allocated to at least one of said optical units and the communication interfaces are operable to exchange communication signals between the optical units, and at least one of the controllers is operable to verify the identifier of the opposing optical unit based on the transmitted communication signals.