Subsea Optical CAN Bus Adaptor for Impedance and Data Integrity
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Solution Overview
Problem
Current CAN bus-based subsea systems face limitations due to impedance drop from multiple electrical devices in parallel and susceptibility to data corruption from short circuit failures and time delays in long transmission lines.
Innovation Solution
The development of devices that adapt CAN buses for subsea optical communication using a CAN transceiver, opto-electrical and electro-optical converters, direction detection circuitry, and transmit-enable circuitry to enable reliable optical communication, preventing closed-loop locks and data corruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple electrical devices are connected in parallel on CAN bus, then network size increases, but impedance drop occurs reducing signal quality
Solution Approach 1:
The patent replaces the electrical CAN bus transmission medium with an optical transmission medium. Optical fibers substitute for electrical wires, eliminating impedance effects that limit network size. The optical domain allows extended transmission distances without signal degradation, enabling larger subsea networks while maintaining signal quality.
Solution Approach 2:
Optical converters serve as intermediary devices that bridge the electrical CAN bus domain and the optical transmission domain. These converters translate electrical signals to optical signals for transmission and back to electrical signals for processing, enabling impedance-free optical communication while maintaining CAN protocol compatibility.
2Length of stationary object
If long transmission lines are used, then network coverage increases, but time delays occur causing data corruption
Solution Approach 1:
The patent substitutes electrical signal transmission with optical signal transmission. Optical signals propagate faster and with less attenuation than electrical signals over long distances. This substitution reduces transmission delays and maintains data integrity across extended subsea distances, eliminating the time delay issues associated with long electrical transmission lines.
3Reliability
If electrical transmission is used, then communication is achieved, but susceptibility to short circuit failures and data corruption occurs
Solution Approach 1:
The patent replaces the electrical transmission medium with an optical transmission medium. Optical fibers are immune to electromagnetic interference, short circuits, and ground loops that plague electrical systems. This substitution eliminates susceptibility to short circuit failures and data corruption while maintaining robust communication capability in the harsh subsea environment.
Solution Approach 2:
Optical converters act as isolating intermediaries that break the electrical continuity between subsea devices and surface equipment. By converting signals to the optical domain for transmission and back to electrical at the receiving end, these converters provide galvanic isolation that protects against short circuits and electromagnetic hazards while enabling reliable communication.
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 reliable and efficient communication over long distances by preventing data corruption and impedance-related issues, allowing for larger network sizes and improved reliability in subsea environments.
Implementation Method 1
an opto-electrical converter coupled to the optical input and configured to convert a signal received on the optical input to an electrical signal
Implementation Method 2
an electro-optical converter coupled to the optical output and configured to convert a signal to an optical signal for transmission on the optical output
Data Source
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AI summary
Messages on controller area net work (CAN) buses are communicated over subsea optical links. An adaptor couples a CAN bus to an optical link. The adaptor detects a direction of transmission, that is, whether a signal began on the CAN bus coupled to the adaptor or on the optical link coupled to the adaptor. Signals from the CAN bus are conditionally transmitted to the optical link depending on the detected direction of transmission. The adaptor can operate at the physical layer without analyzing contents of the CAN bus communications.