Engine Control Stop-Line Interface for One-Wire Communication

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Solution Overview

Problem

Existing communication solutions for internal combustion engines face challenges in maintaining low production costs and high reliability, particularly due to the need for power transfer and protection against voltage transients, which are not adequately addressed by existing one-wire bus systems.

Innovation Solution

A connection between the stop button and electronic control circuit is used for both power supply and data communication, incorporating a low-pass filter and a one-wire bus for two-way communication, with a communication interface converting signals to a conventional RS-232 protocol to enable communication with external computers, and a capacitor for power storage during engine shutdown.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a one-wire bus is used for two-way communication, then the number of wires is reduced, but the system cannot provide power transfer and protection against voltage transients

Engineering Contradiction:
Improvenumber of wiresVSAvoidprotection against voltage transients
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The existing stop button connection is made multi-functional by using it for both its original stop function and for data communication with external computers. This allows the system to communicate without adding new wires, while the existing protection circuitry continues to protect against voltage transients.

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

Solution Approach 2:

A communication interface unit is introduced as an intermediary between the control system and external computers. This interface handles the communication protocols and provides galvanic isolation, protecting the control system from voltage transients while enabling data exchange.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the stop button connection is used for data communication, then production costs are reduced, but power supply during engine shutdown becomes problematic

Engineering Contradiction:
Improveproduction costsVSAvoidpower supply during shutdown
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

A capacitor is charged during engine operation when power is available. This pre-charged capacitor then supplies power to the control system during engine shutdown, enabling communication and other functions to continue without external power.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stop button connection is used for multiple purposes: original stop function, data communication, and power transfer. This multi-functionality eliminates the need for separate power and communication connections, reducing production costs while maintaining power supply capability.

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

3Reliability

If protection against voltage transients is implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprotection against voltage transientsVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The existing stop button connection already includes protection against voltage transients as part of its original design. This existing protection is leveraged for the communication function without requiring additional protection circuitry, avoiding increased device complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The communication interface unit provides galvanic isolation and protection against voltage transients between the control system and external computers. This intermediary handles the protection requirements, allowing the control system to maintain its simple design while still achieving high reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution reduces component count and production costs, provides protection against voltage transients, and allows for reliable data communication between the engine control unit and external computers, ensuring continuous power to the control system and other components.

Implementation Method 1

a capacitor is charged by said external voltage supply, and said capacitor supplies power to the electronic control circuit in the absence of external voltage supply via the connection or voltage supply from the engine

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

said connection comprises a low-pass filter arranged between the electronic control circuit and the stop button, which has the advantage of acting as a protection against voltage transients

Methodology Applied
Scientific EffectLow-pass filtering: Filter (electronic)

Data Source

PatentEP1875060B1Device and method for communication between a control system for small internal combustion engines and an external computer
Publication Date: 2023.07.26 SEM AB
  • EP1875060B1 patent drawingFigure 1a~1b
  • EP1875060B1 patent drawingFigure 2
  • EP1875060B1 patent drawingFigure 3

AI summary

By incorporating digital control systems for ignition of, and to some extent for fuel injection in, small internal combustion engines, opportunities have been created for the connection of external computers, in order thereby to be able to change the characteristics of the control system, as well as to be able to read operational data from the same. The operational data may be e.g. operating time and trip meter. The method according to the invention means that a combined communication port and stop entry is created, which will result in a cost-effective implementation of the communication interface when a stop entry with an associated transient protection already exists.