A Vehicle Electrical System Architecture Based on a Multiplexed Design For Operator Controls and Indicators 2001-01-2740
Increased features content, with electrical effects, have produced tremendous complexity in the design and support of the electrical system for commercial vehicles. Using individual wires coupled with various electro-mechanical components, to implement electrical system features, is no longer a desirable solution. Adding more wires and connectors reduces reliability and makes diagnosing electrical failures rather cumbersome. Likewise, customizing a vehicle with a specific set of features, by using discrete wire designs, make the assembly process prone to error.
This paper explores a new approach to a vehicle electrical architecture that uses multiplexed wiring methods coupled with a programmable central control module. The most novel feature of the system is that the main electrical system control module may be reprogrammed with a unique set of vehicle features as required by each customer order.
Additional benefits of the system include an ability to add more input/output capability to the electrical system by adding various general purpose circuit modules, as nodes, on the back bone of various serial data communication links on the vehicle. Likewise, information gathered from these modules may be shared with any of the other intelligent electrical system components, which minimizes redundant sensors and lowers overall vehicle cost. Due to increased communication between intelligent circuit modules on the vehicle, more of the electrical system may now be diagnosed, either with on board displays or by off board diagnostic equipment.
This new approach allows the set of vehicle features offered and ultimately much of the electrical design, to be managed from a software database, instead of through thousands of combinations of wire harness designs using “hard wired relay logic”. Building upon that capability, now the vehicle order to manufacturing process may be automated to further enhance the speed and agility of the OEM to provide exactly what the customer wants.