Control Valve Closing Time Adaptation for Engine Mixture Accuracy

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Solution Overview

Problem

Inaccuracies in air or fuel mass fed to the combustion chamber due to component variations in tank ventilation systems lead to inaccuracies in mixture formation, affecting lambda controller quality and combustion processes.

Innovation Solution

A method for controlling a control valve that determines the closing time based on a measured variable, using a pulse width modulated signal to control the fluid flow from a tank filter to an internal combustion engine's intake manifold, accounting for mechanical and electrical component tolerances, with a sensor monitoring pressure, flow, or lambda values to set and adjust the pulse duty factor for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If component variations in the tank venting system are present, then manufacturing tolerances and component aging cause inaccuracies in air and fuel mass supply, but implementing adaptive control to compensate for these variations increases device complexity

Engineering Contradiction:
Improveair and fuel mass supply accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism by determining the actual closing time of the control valve through sensor monitoring and comparing it with expected values. This feedback loop enables the control unit to detect deviations caused by component variations and compensate for them by adjusting the duty cycle, thereby maintaining accurate air and fuel mass supply without requiring complex manual calibration systems

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system performs self-calibration by automatically determining the actual closing time of the control valve during operation. The system uses the monitored measured variable (pressure, flow, or lambda) to autonomously identify the closing point and adjust the duty cycle accordingly, eliminating the need for external calibration equipment or complex manual adjustment mechanisms

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If the control valve switching behavior is influenced by mechanical and electrical component tolerances, then component variations affect the precision of fluid flow control, but increasing measurement and adjustment mechanisms to improve precision increases device complexity

Engineering Contradiction:
Improvecontrol valve switching precisionVSAvoidmeasurement and adjustment mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical adjustment mechanisms with an electronic control approach. Instead of using mechanical devices to physically adjust the control valve characteristics, the system uses a control unit that monitors the measured variable and dynamically adjusts the duty cycle of the actuation signal, thereby compensating for mechanical and electrical tolerances through electronic means rather than mechanical complexity

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

Solution Approach 2:

The patent changes the operational parameters of the control valve by dynamically adjusting the duty cycle based on the monitored measured variable. Instead of modifying the physical characteristics of the valve components, the system maintains precision by varying the temporal parameter (duty cycle) of the actuation signal, allowing compensation for component tolerances through parameter adaptation rather than physical modification

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3564514A1Method for controlling a control valve
Publication Date: 2019.11.06 VOLKSWAGEN AG
  • EP3564514A1 patent drawingFigure 1
  • EP3564514A1 patent drawingFigure 2~3
  • EP3564514A1 patent drawingFigure 4

AI summary

Method for controlling a control valve (1), wherein the control valve (1) controls a fluid flow from a filter (2) of a tank (3) to an intake manifold (4) of an internal combustion engine (5), wherein the control valve (1) is actuated to open and close by a control unit (6) by means of a signal (7); wherein the method comprises at least the following steps: a) performing a closing operation (8) of the control valve (1); b) determining a first control value (9) of a duty cycle (10), wherein a closing time (13) of the control valve (1) is determined via a sensor (11) based on a change in a measured quantity (12) monitored by the sensor (11); c) using the first control value (9) at least during an actuation of the control valve (9) following steps a) and b) to open and close the control valve (9).