Two-Wire Bus System for Automotive Data and Power Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication bus systems in vehicles, such as those used for connecting microphones and other sensors/actuators to headend control units, are plagued by excessive wiring, high costs, and weight issues due to the need for multiple connectors and expensive cables, while existing bus systems like MOST150, Flexray, and SPDIF/AES3 suffer from complexity, synchronization issues, bandwidth limitations, and lack of multichannel support.
Innovation Solution
A two-wire bi-directional point-to-point serial bus system that uses a transceiver with switching capabilities to selectively connect to upstream and downstream bus segments, includes power switches for bias voltage application, and circuit monitoring for fault detection, allowing for efficient data and power distribution without a separate ground connection, and supports multiple PCM channels with embedded clock information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple connectors and expensive cables are used for connecting microphones and sensors to headend control units, then communication reliability is improved, but wiring complexity and cost increase
Solution Approach 1:
The patent combines multiple communication channels (data, power, ground) into a single two-wire bus system. The bi-directional transceiver integrates both data communication and power delivery functions, eliminating the need for separate connectors and cables for each function. This merging approach maintains communication reliability while dramatically reducing wiring complexity.
Solution Approach 2:
The two-wire bus system serves multiple functions simultaneously: it provides bidirectional data communication, power distribution to slave devices, and implicit ground reference. The single bus structure replaces multiple dedicated connections, achieving universality by making one system perform the roles of several separate systems.
2Productivity
If existing bus systems like MOST150, Flexray, and SPDIF/AES3 are used, then communication bandwidth is improved, but system complexity and cost increase
Solution Approach 1:
The transceiver recovers clock information from the data stream itself without requiring separate clock lines or complex synchronization infrastructure. The system uses the existing data communication channel to carry timing information, allowing slave devices to synchronize automatically. This self-service approach provides sufficient bandwidth for audio applications while keeping the system simple and cost-effective.
3Stability of the object's composition
If separate ground connections are provided for each device, then electrical stability is improved, but wiring complexity and weight increase
Solution Approach 1:
The two-wire bus provides multiple functions including power delivery, data communication, and implicit ground reference through the return path. By making the bus universal and bi-directional, the system achieves electrical stability without requiring separate ground wires for each device, thereby reducing overall wiring weight and complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various embodiments of the present invention provide a two-wire (e.g., unshielded twisted pair) bus system that is simple (e.g., no microcontroller required in slave devices), synchronous with embedded clock information, inexpensive, automotive EMC compliant, and has sufficient speed and bandwidth for a large number of slave devices/peripherals, and also provides various protocols that can be used in various communication systems such as a two-wire bus system. The two-wire bus optionally may be self-powered, i.e., the master device may provide power to the slave devices over the two-wire bus. Various embodiments of the present invention methods for discovery, configuration, and coordinating data communications between master and slave devices in a communication system. Exemplary embodiments are described with reference to a two-wire point-to-point bus system, although the method can be used in other communication systems. Provisions are included for controlling the sequential powering of the bus and slave devices.