Vehicle Databus Daisy-Chain Slave Module Position Learning
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Solution Overview
Problem
The existing radio-based vehicle access systems require precise and individually defined installation positions for slave modules, leading to high logistical efforts and increased susceptibility to errors due to the need for unique installation locations for each module.
Innovation Solution
A radio-based vehicle access system with a data bus system that allows identical slave modules to be installed in various positions using a daisy chain configuration, where the unique installation positions are taught via the data bus system, enabling the use of a single logistics part number and reducing assembly effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If slave modules are assigned individually predetermined installation positions, then precise location determination of the vehicle key is improved, but logistical effort and susceptibility to installation errors increase
Solution Approach 1:
The system changes the parameter of installation position identification from physical uniqueness (customized modules with specific part numbers) to data-based identification (learning and storing installation positions via data bus communication). This allows identical hardware modules to be assigned different logical positions through software configuration rather than physical customization.
Solution Approach 2:
Instead of using physically unique modules for each installation position, the system uses identical slave module copies that receive their individual position information through data bus communication. The control unit learns and stores the installation position of each slave module via the data bus, creating a digital copy of the position information rather than relying on physical differentiation.
2Ease of manufacture
If identical slave modules are used in various positions, then manufacturing and installation effort are reduced, but the ability to determine precise installation positions must be improved
Solution Approach 1:
The control unit automatically learns the installation positions of slave modules through data bus communication during system initialization or configuration. Rather than requiring manual configuration or pre-programming of position data, the system performs self-identification by having the control unit query and store the installation position information of each slave module autonomously.
Solution Approach 2:
The system implements a feedback mechanism where slave modules communicate their installation position information back to the control unit via the data bus. The control unit receives this feedback information and stores it for later use in determining vehicle key location, creating a closed-loop system that automatically configures itself.
Data Source
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AI summary
The invention relates to a databus system (120) for a vehicle, which system has a master module (121) with a master-bus transceiver (124) and at least one first slave module (122a) and a second slave module (122b) of identical structure to the first, which are arranged in a daisy-chain configuration with the master module (121). The first slave module (122a) has a separately formed bus activation circuit (127a) with a first switching element (128a), which is connected on the input side to a first slave-bus transceiver (125a) and a first microcontroller (126a) of the first slave module (122a) and on the output side to a second slave-bus transceiver (125b) of the second slave module (122b). In addition, the first switching element (128a) can be controlled by a voltage signal of the first microcontroller (126a) for selective connection and disconnection of the second slave-bus transceiver (125b) to/from the master-bus transceiver (124). The invention also relates to a radio-based vehicle access system (100) comprising such a databus system, and to a method for learning slave modules (122a-122d).