Hybrid Vehicle Downhill Control Strategy for Fuel Efficiency

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Solution Overview

Problem

Existing control apparatuses for hybrid vehicles struggle to maintain effective fuel consumption improvements when road information updates occur mid-travel on downhill sections, leading to potential discontinuation of specific control strategies that optimize battery state of charge, resulting in reduced fuel efficiency.

Innovation Solution

A control apparatus that continuously executes specific control until the end point of a targeted downhill section, even if the section is updated during travel, by using a controller to manage the vehicle's internal combustion engine and electric motor to maintain a target battery charge level, ensuring regenerative braking energy is effectively utilized and fuel consumption is optimized.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the control apparatus updates the controlled target section based on newly acquired road information during downhill control, then the control system can adapt to new information, but the downhill control may be discontinued before reaching the original end point, reducing fuel consumption improvement

Engineering Contradiction:
Improveadaptability to road information updatesVSAvoidfuel consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The control apparatus stores the end point information of the controlled target section before road information updates occur. This preliminary storage of critical control parameters ensures that when updates happen, the system can maintain the original control objectives and continue downhill control to the originally planned end point, preventing premature discontinuation and ensuring complete energy recovery opportunities are utilized

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control apparatus continuously monitors the vehicle's position relative to the stored end point of the controlled target section. By providing feedback on whether the vehicle has reached the predetermined end point, the system ensures that downhill control continues for the complete intended duration and distance, maximizing fuel consumption improvement while still allowing road information updates to occur

Inventive Principle:
Principle #23Feedback

2Loss of energy

If the control apparatus continues downhill control to the original end point even after road information updates, then fuel consumption improvement is maximized, but the control system cannot respond to new road information

Engineering Contradiction:
Improvefuel consumptionVSAvoidresponse to road information updates
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The control apparatus stores the end point information of the controlled target section before road information updates occur. This preliminary storage of critical control parameters ensures that when updates happen, the system can maintain the original control objectives and continue downhill control to the originally planned end point, preventing premature discontinuation and ensuring complete energy recovery opportunities are utilized

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control apparatus performs more complete downhill control by continuing to the originally stored end point rather than stopping at the new updated section end point. This excessive action ensures that all available regenerative braking opportunities are captured, maximizing energy recovery and fuel consumption improvement, while the system remains adaptable by allowing future updates to initiate new controlled target sections

Inventive Principle:
Principle #16Partial or excessive 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

This approach ensures continuous execution of downhill control until the vehicle reaches the end point of the targeted section, thereby maintaining and enhancing fuel consumption performance by preventing unnecessary battery charge limit exceedance and promoting efficient energy recovery.

Implementation Method 1

a repetitive change in an extremely large remaining amount of charge (hereinafter, also simply referred to as state of charge (SOC)) or extremely small remaining amount of charge of the storage battery accelerates the performance degradation of the storage battery

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

electric energy that is generated as a result of regenerative braking is transformed into thermal energy in a friction brake device or an inverter or both

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3124302B1Control apparatus
Publication Date: 2019.07.03 TOYOTA JIDOSHA KK
  • EP3124302B1 patent drawingFigure 1
  • EP3124302B1 patent drawingFigure 2
  • EP3124302B1 patent drawingFigure 3

AI summary

A control apparatus for a hybrid vehicle searches for and determines a scheduled travel route and a downhill section included in the scheduled travel route on the basis of positional information of the vehicle and road information. The control apparatus determines a section from a downhill control start point to an end point of a target downhill section as a controlled target section. The downhill control start point is located a predetermined first distance before a start point of the target downhill section. When the vehicle (10) travels on the controlled target section, the control apparatus executes downhill control. Even in a situation in which a target downhill section is newly determined during execution of the downhill control, the control apparatus continues the downhill control until the vehicle reaches an end point of the controlled target section for which the downhill control is started.