Vehicle Engine Stop-on-Move Control for Brake-Based Restart Inhibition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicles with both stop-start and stop on the move technology unnecessarily restart the engine when braking force conditions are not met, leading to increased fuel consumption and unexpected engine restarts, which degrade the driving experience.
Innovation Solution
A controller that monitors vehicle speed and braking force thresholds to inhibit engine restarts under certain conditions, maintaining the engine in a stopped state until specific criteria are met, such as a decrease in braking force or an imminent demand for positive torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is stopped during motion (stop on the move), then fuel economy is improved, but the engine may restart unnecessarily when braking force conditions are not met
Solution Approach 1:
The system dynamically adjusts engine restart logic based on braking force conditions. When stop on the move is activated and the vehicle comes to rest, the controller evaluates whether braking force exceeds a threshold before allowing engine restart. This dynamic condition-based approach prevents unnecessary restarts while ensuring reliable operation when needed.
Solution Approach 2:
The controller continuously monitors braking force magnitude and uses this feedback to determine engine restart timing. By measuring the actual braking force applied and comparing it against predetermined thresholds, the system intelligently decides whether to maintain engine stop or initiate restart, optimizing both fuel economy and operational reliability.
2Ease of operation
If the engine restarts when braking force is below threshold, then the vehicle can provide creep torque, but fuel consumption increases and driver experience deteriorates
Solution Approach 1:
The system implements dynamic engine management that adapts to real-time braking conditions. Instead of using a fixed restart criterion, the controller adjusts restart decisions based on the magnitude of braking force detected, allowing the vehicle to maintain stopped engine state longer when light braking is applied, thereby reducing fuel consumption while preserving necessary vehicle control capabilities.
Solution Approach 2:
The invention changes the restart parameter from a simple speed-based criterion to a composite criterion incorporating both speed and braking force magnitude. By introducing braking force as an additional parameter, the system can distinguish between deliberate stopping (where restart may be unwanted) and natural deceleration (where restart provides benefit), optimizing fuel consumption without compromising vehicle control.
3Use of energy by moving object
If the driver applies braking force to satisfy stop-start threshold, then the engine stops, but the driver must maintain braking pressure to prevent unexpected restart
Solution Approach 1:
The system performs preliminary evaluation of braking force conditions before triggering engine restart. By assessing whether braking force exceeds the threshold at the moment the vehicle comes to rest, the controller can predictively determine restart appropriateness, allowing the driver to release the brake pedal naturally without worrying about maintaining pressure to prevent unexpected engine restart.
Solution Approach 2:
The braking system serves a dual function: it provides the stopping force the driver intends and simultaneously acts as a sensor to determine engine restart conditions. The braking force measurement, already available for vehicle control, is repurposed to inform engine management decisions, eliminating the need for separate driver actions to maintain engine stop status.
Data Source
AI summary
The present invention relates to a method of controlling a vehicle. The method comprises stopping (12) an engine (2) of the vehicle (1) when a speed of the vehicle (1) is greater than or equal to a speed threshold, and inhibiting (17) starting of the engine (2) if the speed of the vehicle (1) falls below the speed threshold and a driver demand for braking force is less than or equal to a braking force threshold. Further aspects of the invention relate to a control system, a system and a vehicle.