Engine Synchronization Using Missing Tooth Verification

Solution Overview

Problem

Existing engine synchronization systems face errors in determining the crank angle due to misidentification of tooth periods, leading to incorrect synchronization of fuel injection and ignition timings, which can prevent engine restart and affect fuel efficiency and durability.

Innovation Solution

The system detects crank teeth numbers using a pulse signal, calculates tooth periods, and verifies the presence of a missing tooth based on both tooth periods and numbers, preventing erroneous synchronization by checking the tooth number within a predetermined range, and adjusts for reverse rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the missing tooth position is determined using only tooth period calculations, then the system can identify missing teeth under normal rotation, but the system produces erroneous determination when the crankshaft rotates in reverse or stalls

Engineering Contradiction:

Improvemissing tooth position detection accuracyVSAvoiddetermination reliability under reverse rotation or stall conditions

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system pre-stores the actual missing tooth position information in a storage unit before engine operation begins. This preliminary action allows the system to have reference data ready, so when determining missing tooth position during operation, it can compare real-time tooth period calculations against the pre-stored accurate position, preventing erroneous determination under reverse rotation or stall conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the determined missing tooth position is continuously verified against pre-stored reference information. The crankshaft signal processing unit compares real-time tooth period data with stored reference data, and only accepts determination results that match the reference, thereby eliminating false detections caused by reverse rotation or stalling events.

Inventive Principle:

Principle #23Feedback

2Productivity

If the system uses tooth period patterns to identify missing teeth, then it can detect missing teeth during normal operation, but it misidentifies regular teeth as missing teeth during engine restart after stalling

Engineering Contradiction:

Improveengine start performanceVSAvoidcrank angle determination accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system pre-stores the actual missing tooth position information in a storage unit before engine operation begins. This preliminary action allows the system to have reference data ready, so when determining missing tooth position during operation, it can compare real-time tooth period calculations against the pre-stored accurate position, preventing erroneous determination under reverse rotation or stall conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the determined missing tooth position is continuously verified against pre-stored reference information. The crankshaft signal processing unit compares real-time tooth period data with stored reference data, and only accepts determination results that match the reference, thereby eliminating false detections caused by reverse rotation or stalling events.

Inventive Principle:

Principle #23Feedback

3Ease of operation

If the system determines crank position based on detected missing tooth position, then it can synchronize engine timing, but it produces incorrect synchronization when missing tooth position is erroneously determined

Engineering Contradiction:

Improveengine synchronization capabilityVSAvoidsynchronization accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system pre-stores the actual missing tooth position information in a storage unit before engine operation begins. This preliminary action allows the system to have reference data ready, so when determining missing tooth position during operation, it can compare real-time tooth period calculations against the pre-stored accurate position, preventing erroneous determination under reverse rotation or stall conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the determined missing tooth position is continuously verified against pre-stored reference information. The crankshaft signal processing unit compares real-time tooth period data with stored reference data, and only accepts determination results that match the reference, thereby eliminating false detections caused by reverse rotation or stalling events.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11313763B2Engine synchronization system and control method thereof

Publication Date: 2022.04.26 HYUNDAI MOTOR CO LTD

AI summary

An engine synchronization method may include: detecting teeth numbers of crank teeth installed on a crankshaft based on a pulse signal generated from a crankshaft position sensor; calculating a tooth period between a falling edge and a next falling edge of the pulse signal generated from the crankshaft position sensor and detecting a missing tooth based on the calculated tooth period; determining whether the detected missing tooth is an actual missing tooth based on a tooth number detected at the time of detecting the missing tooth; and performing synchronization control of an engine when it is determined that the detected missing tooth is the actual missing tooth.