Hybrid EV Engine Start Control with Delayed Fuel Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid electric vehicles face limitations in controlling torque variation during engine start, leading to vibration and non-driving fuel loss due to the damping force of the belt connecting the hybrid starter generator and engine, which results in inefficient fuel injection timing.
Innovation Solution
A method and system for controlling fuel injection in hybrid electric vehicles by inhibiting engine injection until specific conditions are met, including shift, powertrain mode, and State of Charge conditions, and performing reaction force control through a first motor directly connected to the engine, allowing precise timing and reducing disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel injection is performed before engine clutch engagement during engine start, then engine starting is achieved, but non-driving fuel loss occurs due to fuel consumption before power transmission to wheels
Solution Approach 1:
The control device delays fuel injection until after engine clutch engagement is confirmed, rather than injecting fuel beforehand. This preliminary timing adjustment ensures that fuel is only consumed when power can be effectively transmitted to the wheels, eliminating non-driving fuel loss while maintaining reliable engine starting through proper sequencing of clutch engagement and fuel injection
Solution Approach 2:
The control device monitors the engagement state of the engine clutch in real-time and uses this feedback information to determine the optimal timing for fuel injection. By continuously checking whether the clutch is engaged and adjusting the fuel injection timing accordingly, the system ensures fuel is injected only when power transmission is established, preventing energy waste
2Object-affected harmful factors
If torque variation is controlled during engine start, then vibration is reduced, but control precision is limited due to belt damping force
Solution Approach 1:
The patent extracts and removes the belt connection between the hybrid starter generator and engine, replacing it with a direct connection. This eliminates the belt's damping force that was limiting torque control precision, allowing for more accurate control of torque variation during engine start and thereby reducing vibration more effectively
Solution Approach 2:
The mechanical belt transmission system is replaced with a direct mechanical connection. This substitution removes the intermediate belt component that introduced damping and control limitations, enabling more precise torque control during engine starting operations
3Productivity
If engine clutch is engaged during fuel injection, then power transmission is established, but vibration is transmitted to drivetrain causing driver disconnection sensation
Solution Approach 1:
The control device ensures the engine clutch is engaged before initiating fuel injection, rather than allowing simultaneous or reverse sequencing. This preliminary engagement of the clutch establishes proper power transmission pathways before fuel is injected and torque is generated, preventing vibration transmission to the drivetrain while maintaining efficient power delivery
Solution Approach 2:
The control device continuously monitors the engagement state of the engine clutch and uses this feedback to determine when to initiate fuel injection. By checking clutch engagement status in real-time and adjusting fuel injection timing accordingly, the system prevents vibration transmission while ensuring efficient power transmission
Data Source
AI summary
A hybrid electric vehicle controlling a fuel injection point-in-time and a method of controlling driving of the hybrid electric vehicle such that fuel efficiency is improved when engine start is required. The method of controlling driving of the hybrid electric vehicle may include: inhibiting engine injection when there is an engine start request and a control entry condition is satisfied, performing the engine injection when an injection allowable condition is satisfied with the engine injection inhibited, and performing reaction force control along with the engine injection through a first motor directly connected to the engine.