Stub Bus Slave Unit Positioning via Voltage Potential Drops

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Solution Overview

Problem

Existing bus systems in vehicles face challenges in efficiently determining the relative positions of slave units connected to a stub bus, which is crucial for addressing and communicating with individual units, especially when multiple units with the same functionality are connected, leading to complexities in addressing and positioning.

Innovation Solution

The method involves using a master unit to determine the relative positions of slave units by measuring reference and positioning voltage potential drops across the power supply and ground lines, with each slave unit operable in different power modes, allowing the master unit to calculate and update the positions based on relative voltage potential drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If sequential connection and address allocation methods are used, then addressing capability is improved, but system complexity and time consumption increase

Engineering Contradiction:
Improveaddressing capabilityVSAvoidsystem complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The slave units automatically determine their own relative positions by measuring voltage potential drops during normal operation. Each slave unit acts as its own positioning device, eliminating the need for external positioning equipment or complex addressing procedures. The system uses the existing power supply lines and operational states of slave units to self-determine positions without requiring additional addressing infrastructure.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If multiple slave units with same functionality are connected, then system versatility is improved, but addressing and positioning complexity increases

Engineering Contradiction:
Improvesystem versatilityVSAvoidaddressing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical/addressing-based positioning systems with an electrical measurement system. Instead of using physical addressing mechanisms or complex identification protocols, the system uses voltage potential drop measurements across power supply lines to determine relative positions. This substitution of measurement methodology simplifies the addressing of multiple functional identical units by using electrical characteristics rather than mechanical or protocol-based identification.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If voltage potential drop measurements are used, then positioning precision is improved, but measurement complexity increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidmeasurement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The power supply lines serve dual functions: providing electrical power to slave units and serving as measurement conduits for determining relative positions. The same infrastructure used for power distribution is utilized for positioning measurements, eliminating the need for separate measurement wiring or additional measurement-specific hardware. This multi-functional use of existing components simplifies the overall measurement system while maintaining positioning precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach enables reliable and efficient determination of the positions of slave units along the stub bus, facilitating accurate addressing and communication, even when multiple units with the same functionality are connected, by leveraging the differences in voltage potential drops across varying power modes.

Implementation Method 1

measuring reference and positioning voltage potential drops across the power supply and ground lines

Methodology Applied
Scientific EffectVoltage potential drop: Ohm's Law

Data Source

PatentEP3419225B1System and method allowing for determining relative positions of slave units along a stub bus
Publication Date: 2020.03.18 NXP BV
  • EP3419225B1 patent drawingFigure 1a~1b
  • EP3419225B1 patent drawingFigure 2
  • EP3419225B1 patent drawingFigure 3a~4

AI summary

The present application relates to a system and a method for determining relative positions slave units (201.1 - 201.n) along a stub bus (50) with at least a power line (30) and a ground line (40). Each slave unit (201.1 - 201.n) is operable in different power modes, which are differentiated by effective resistances between the power (30) and ground lines (40). A reference voltage potential drop is determined for each slave unit (201.1 - 201.n) while the slave units (201.1 - 201.n) are operating in a first power mode. A positioning voltage potential drop is determined for one or more slave units (201.1 - 201.n) while a selected slave unit (201.1 - 201.n) is operating in a second power mode. Relative positions of the slave units (201.1 - 201.n) are determined based on the relative voltage potential drops obtained from the reference and positioning voltage potential drops.