Engine Restart Control Prioritization for 48V Mild Hybrid Vehicles

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Solution Overview

Problem

Current engine restart control systems do not effectively prioritize different start situations, leading to suboptimal fuel efficiency and increased start failure risks, particularly in 48V vehicles with mild hybrid starter & generator systems.

Innovation Solution

A method of controlling engine restart that prioritizes inertial, MHSG, starter, and injection starts based on specific conditions such as vehicle speed, accelerator pedal position, and battery state of charge, using a start controller to determine the most appropriate start strategy and implement backup starts to ensure successful engine restart.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If engine restart control prioritizes multiple start situations (inertial, MHSG, starter, injection starts), then fuel efficiency is improved and start failure situations are reduced, but device complexity increases due to multiple control strategies

Engineering Contradiction:

Improvestart success rateVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the engine restart control into multiple distinct start situations (inertial start, MHSG start, starter start, injection start), each with its own control strategy and priority level. The start controller divides the restart control function into separate determination processes for each start situation, allowing targeted optimization without requiring complete redesign of the entire control system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic prioritization where the start controller adjusts the priority of different start situations based on real-time vehicle conditions. The control strategy dynamically selects which start method to attempt first based on factors like battery state of charge, engine speed, and driving conditions, allowing the system to adapt to changing operational requirements.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If multiple start control strategies are implemented with prioritization, then fuel efficiency is enhanced through optimized start selection, but ease of operation deteriorates due to complex control logic

Engineering Contradiction:

Improvefuel efficiencyVSAvoidcontrol logic simplicity

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The start controller autonomously determines the most appropriate start situation and executes the corresponding control strategy without requiring manual intervention from the driver. The system self-evaluates available start methods, checks their feasibility based on current vehicle state, and automatically selects the optimal start approach, making the complex control logic transparent to the user.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent incorporates feedback mechanisms where the start controller continuously monitors vehicle operating conditions (engine speed, battery state, transmission state) and adjusts the start control strategy based on this feedback. The system evaluates the results of each start attempt and uses this information to refine subsequent start decisions, optimizing fuel efficiency through learned operational patterns.

Inventive Principle:

Principle #23Feedback

3Reliability

If backup start determination is implemented to complement initial start failure, then reliability is improved by reducing start failures, but loss of time increases due to additional determination steps

Engineering Contradiction:

Improvestart reliabilityVSAvoidstart determination time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent prepares backup start strategies in advance by pre-defining alternative start methods and their associated control parameters. When the primary start situation is determined, the corresponding backup strategy is already ready for immediate execution if needed, eliminating the need for time-consuming analysis during the actual start attempt.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a cushioning mechanism by having predetermined backup start determinations ready before actual start failures occur. The start controller maintains ready-state backup strategies that can be quickly activated if the primary start method fails, providing a safety buffer that prevents complete start failure without requiring extensive real-time decision-making.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS11220989B2Method of controlling engine restart of vehicle

Publication Date: 2022.01.11 HYUNDAI MOTOR CO LTD

AI summary

A method of controlling engine restart may include selecting, by a start controller, a first start situation and a second start situation for restarting an engine; determining a current possible start-up through the first and second start situations; prioritizing possible start-ups; and attempting to restart the engine by setting the first and second start situations as first start control and second start control, respectively, based on the priorities of the start-ups.