Solenoid Current Control with Forward Prediction

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Solution Overview

Problem

Traditional engine control systems fail to accurately and quickly control solenoid current in diesel engine systems due to solenoid variations and system aging, leading to inaccuracies in regulating the bypass valve.

Innovation Solution

An engine control system comprising a current control module and a solenoid actuator module that determines a duty cycle based on the desired current and solenoid resistance, corrects resistance based on actual current, and actuates the solenoid using pulse-width modulation, allowing for precise and rapid control of solenoid current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a fast-response PID control scheme is used to control solenoid current, then the response speed is improved, but the accuracy deteriorates due to aliasing oscillations in feedback signals

Engineering Contradiction:

Improvecontrol response speedVSAvoidfeedback signal accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by predicting the solenoid current before it is actually measured. The controller calculates an expected current value based on the duty cycle and solenoid resistance, then uses this prediction to generate feedback signals. This eliminates the need for actual current sensing and removes aliasing oscillations from the feedback path, allowing fast-response control without accuracy loss.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If a slow-response filter is used to smooth feedback signals, then the measurement precision is improved by removing oscillations, but the speed deteriorates due to delayed feedback

Engineering Contradiction:

Improvefeedback signal smoothnessVSAvoidfeedback response speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent eliminates the need for filtering by using predicted current values as feedback. Since the controller calculates the expected current based on the duty cycle and resistance model, there are no oscillations to filter. This provides instantaneous, smooth feedback without the delay inherent in filtered signals.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical filtering process with an electronic calculation-based prediction system. Instead of using a slow-response filter to smooth signals, the controller uses mathematical prediction based on the duty cycle and resistance model to generate instant feedback, substituting physical filtering with computational prediction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If traditional control systems use solenoid temperature to determine current, then the device complexity is reduced, but the accuracy deteriorates due to solenoid variations and system aging

Engineering Contradiction:

Improvecontrol system simplicityVSAvoidsolenoid current accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring the actual solenoid resistance and using this information to correct the predicted current values. The controller adjusts the duty cycle based on the difference between expected and actual current, creating a closed-loop system that compensates for solenoid variations and aging without requiring complex temperature-based models.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes the control parameter from solenoid temperature to duty cycle. By directly controlling the duty cycle and calculating the expected current from this parameter, the system achieves more accurate control. The system then uses resistance feedback to adjust the duty cycle, creating a more precise parameter-based control approach.

Inventive Principle:

Principle #35Parameter changes

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

Enables accurate and rapid control of solenoid current, improving the regulation of the bypass valve and enhancing the overall efficiency of the diesel engine system by predicting and correcting the duty cycle and resistance in real-time.

Implementation Method 1

The magnetic solenoid actuator typically includes a solenoid coil and a magnetic core. The bypass valve is opened and closed by selectively supplying current through the solenoid coil.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8109256B2Solenoid current control with direct forward prediction and iterative backward state estimation

Publication Date: 2012.02.07 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An engine control system comprises a current control module and a solenoid actuator module. The current control module determines a duty cycle based on a desired current through a solenoid of an engine system and a resistance of the solenoid and corrects the resistance based on an actual current through the solenoid. The solenoid actuator module actuates the solenoid based on the duty cycle.