Fault-Tolerant Communication Bus Ring Topology
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication bus systems, such as the CAN bus, face challenges in harsh environments like automotive settings due to high costs, complex protocols, and limited functionality in harsh conditions, requiring a fault-tolerant and cost-effective solution for reliable data transmission.
Innovation Solution
A bidirectional communication bus system with a ring topology and a bus master that can selectively break the ring while remaining in communication, coupled with isolatable segments and switches at each bus slave to manage differential voltages and provide galvanic isolation, enabling efficient data transmission over a two-wire interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard CAN bus protocol is used for reliable communication in harsh environments, then fault tolerance and noise immunity are improved, but system cost and protocol complexity increase
Solution Approach 1:
The patent uses inexpensive discrete components (resistors, capacitors, optoisolators) to build a custom communication interface that replaces expensive CAN bus controllers and protocol stacks, achieving comparable reliability through hardware-level design rather than software complexity
Solution Approach 2:
The patent replaces the electronic/software-based CAN protocol processing with an optical isolation mechanism using optoisolators, substituting electrical signal processing with optical coupling to achieve noise immunity and fault tolerance without complex protocol handling
2Object-affected harmful factors
If galvanic isolation is implemented using optoisolators in harsh environments, then noise immunity and fault tolerance are improved, but device cost and circuit complexity increase
Solution Approach 1:
The patent divides the communication interface into isolated segments using optoisolators, separating the high-voltage/harsh environment side from the low-voltage control side, allowing each segment to be independently designed and tested for specific noise conditions
Solution Approach 2:
The optoisolator acts as an intermediary between the harsh environment and the control circuitry, transferring signals through optical coupling while providing galvanic isolation, thereby protecting sensitive circuits from noise and voltage spikes without requiring complex filtering or shielding
3Reliability
If a ring topology communication bus is used for fault tolerance, then reliability is improved, but the ability to isolate faulty segments and maintain communication on healthy segments is reduced without selective breaking capability
Solution Approach 1:
The patent makes the ring topology dynamic by enabling the bus master to selectively break the ring at will, allowing the system to switch between ring mode (for fault tolerance) and linear mode (for segment isolation and reconfiguration), adapting to different operational requirements in real-time
Solution Approach 2:
The communication bus is designed to serve multiple functions: it can operate as a closed ring for maximum fault tolerance, or be selectively broken to isolate faulty segments, or reconfigured to accommodate different numbers of slaves, providing universal adaptability across various fault and configuration scenarios
4Device complexity
If bidirectional half-duplex communication is implemented on a two-wire interface, then cost is reduced, but noise immunity and reliability in harsh environments deteriorate
Solution Approach 1:
The patent changes the electrical parameters of the two-wire interface by incorporating termination resistors and pull-up/pull-down resistors, optimizing the voltage levels and impedance matching to enhance noise immunity while maintaining the simple two-wire bidirectional half-duplex architecture
Solution Approach 2:
The patent incorporates RC filtering circuits and proper termination resistors in advance on the two-wire interface, providing cushioning against noise and signal reflections before they can corrupt the data, thereby enabling reliable communication over the cost-effective two-wire interface in harsh environments
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
The solution achieves low-cost, bidirectional, half-duplex operation with high immunity to noise and fault tolerance, allowing reliable communication in harsh environments, including automotive applications, by using optoisolators for galvanic isolation and resistor ladders for differential voltage management.
Implementation Method 1
using optoisolators for galvanic isolation
Implementation Method 2
optoisolators provide galvanic isolation
Implementation Method 3
resistor ladders for differential voltage management
Implementation Method 4
enabling efficient data transmission over a two-wire interface
Data Source
AI summary
A communication bus system is provided. The communication bus system includes a communication bus having a plurality of isolatable segments and a bus master coupled to a first end of the communication bus. The bus master is configured to couple to a second end of the communication bus and to decouple from the second end of the communication bus based on a selection signal. A method for operating a communication bus is also disclosed.