Alternator-Starter Engine Restart State Machine

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Solution Overview

Problem

Integrating an alternator-starter engine stop/start system into vehicles with manual gearboxes is challenging due to driver influence on the transmission system, varying driving habits, and the need for a tailored engine restart strategy.

Innovation Solution

A reversible rotating electric machine-based engine stop/start system with an electronic control module, state machine, and sensors to detect vehicle component states, enabling controlled engine restarts through sequential monitoring and pre-magnetization of the rotor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a starter-alternator engine start/stop system is integrated into a vehicle with a manual transmission, then the engine can be stopped and restarted, but the driver's direct influence on the transmission system through clutch pedal and gearshift lever actions makes it difficult to define an engine restart strategy

Engineering Contradiction:
Improveengine restart strategy automationVSAvoidadaptability to varying driving habits
Core Design Contradiction:
Extent of automationVSAdaptability or versatility

Solution Approach 1:

The system uses a state machine to monitor driver actions (clutch pedal, gearshift lever, brake pedal) and anticipates future engine restart needs before they actually occur. By detecting patterns in the driver's actions and predicting when an engine restart will be needed, the system can prepare and execute restart commands proactively, rather than reactively responding to actual restart requests. This preliminary action approach allows the system to handle the complexity of manual transmission systems by anticipating driver intentions.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the engine restart control module monitors driver actions to anticipate restart needs, then controlled engine restarts can be achieved, but the system complexity increases due to multiple sensors and state machine logic

Engineering Contradiction:
Improvecontrolled engine restartsVSAvoidsensors and control module complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control system is segmented into distinct functional components: multiple simple sensors (clutch pedal sensor, gearshift lever sensor, brake pedal sensor) that independently detect specific driver actions, a state machine that processes these sensor inputs according to predefined transition rules, and an engine restart control module that executes restart commands. This segmentation allows each component to remain relatively simple while the combination provides sophisticated control capability. The state machine acts as an intermediary that manages the complexity of coordinating these components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system continuously monitors the states of the clutch pedal, gearshift lever, and brake pedal through sensors, and uses this feedback information to update the state machine's assessment of driver intentions. The state machine transitions between different states based on the feedback from these sensors, allowing it to adapt to the driver's actual actions in real-time. This feedback mechanism ensures that the engine restart control is based on actual driver behavior patterns rather than assumptions.

Inventive Principle:
Principle #23Feedback

3Loss of time

If the state machine monitors sequential states of on-board components, then engine restart can be anticipated, but the response time for engine restart increases due to sequential monitoring

Engineering Contradiction:
Improveengine restart response timeVSAvoidstate machine monitoring complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The state machine is designed to detect patterns in driver actions that indicate an upcoming engine restart need and to anticipate the restart requirement before the actual restart occurs. By monitoring the sequential states of the clutch pedal, gearshift lever, and brake pedal, the system can identify situations where the driver is likely to need an engine restart soon (such as when the clutch is released, gearshift is in neutral, and brake is pressed), and can prepare the restart sequence in advance. This preliminary anticipation reduces the effective response time by eliminating delays associated with reacting to actual restart requests.

Inventive Principle:
Principle #10Preliminary action

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 predictable and controlled engine restarts in vehicles with manual gearboxes by anticipating driver actions and managing the clutch system, improving the integration of stop/start technology.

Implementation Method 1

a reversible rotating electric machine of the alternator-starter type

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

command a pre-magnetization operation of a rotor of the reversible rotating electric machine

Methodology Applied
Scientific EffectMagnetization: Magnetism

Data Source

PatentEP2140132B1System for stopping/restarting an engine with alternator-starter
Publication Date: 2019.09.11 VALEO EQUIP ELECTRIC MOTEUR
  • EP2140132B1 patent drawingFigure 1
  • EP2140132B1 patent drawingFigure 2
  • EP2140132B1 patent drawingFigure 3A~3B

AI summary

The invention relates to an engine stop/restart system that comprises a reversible rotary electric machine of the alternator-starter type (10) and electronic means (11, 12, 13) including an engine restart driving module (131). According to the invention, the engine stop/restart system also includes detection means (S1 to S4) fitted on the onboard equipment (L4, S1 to S4) of the vehicle for detecting a state of the onboard equipment, and a state machine (SM) comprised in the engine restart driving module and capable of anticipating a thermal engine restart instruction from a sequential follow-up of the onboard equipment states. The invention thus provides an engine stop/restart system with an alternator-starter, which can be integrated in a vehicle with a manual gearbox.