Hybrid Engine Start Timing via Predicted Power Profiles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles face challenges in optimizing engine start times based on powertrain power output profiles to enhance fuel efficiency and drivability, particularly in scenarios where the electric machine's power limits are approached, leading to inefficient energy management.
Innovation Solution
A controller is programmed to generate powertrain power output profiles based on navigation data, initiating an engine start before an upcoming increase in power demand exceeds a threshold, and maintaining electric machine operation when demands are below the threshold, ensuring optimal energy distribution between the engine and electric machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is kept shutdown to improve fuel efficiency, then fuel consumption is reduced, but the powertrain may not have sufficient power available when high power demand occurs
Solution Approach 1:
The controller initiates engine start before the power demand exceeds the electric machine's power limit, based on the predicted powertrain power output profile. This preliminary action ensures the engine is ready to provide power when needed, preventing power deficiency while maintaining fuel efficiency by keeping the engine shutdown during periods when electric power is sufficient.
2Power
If the engine is started early to ensure sufficient power availability, then powertrain power output is ensured, but fuel consumption increases due to unnecessary engine operation
Solution Approach 1:
The engine start is initiated at an optimal time based on the predicted power demand profile, not too early and not too late. The controller uses the powertrain power output profile to determine the precise moment when engine start should occur to meet upcoming power demands while minimizing unnecessary engine operation time, thus optimizing fuel consumption.
Solution Approach 2:
The engine start control strategy is dynamic, adjusting the engine start timing based on real-time conditions including the predicted power demand profile, current vehicle state, and powertrain operating conditions. This dynamic approach allows the system to optimize the balance between power availability and fuel consumption for each specific driving scenario.
3Use of energy by moving object
If the electric machine operates alone for extended periods, then fuel efficiency is improved, but the system may not respond quickly enough to sudden high power demands
Solution Approach 1:
The controller predicts future power demands using the powertrain power output profile and initiates engine start in advance of the actual power demand occurrence. This preliminary action eliminates the response delay that would occur if the engine were started only after power deficiency was detected, while still allowing the electric machine to meet current power demands efficiently.
Data Source
AI summary
A vehicle includes a powertrain and a controller. The powertrain has an engine and an electric machine that are each configured to generate power within the powertrain to propel the vehicle. The controller is programmed to, generate a powertrain power output profile required to propel the vehicle over a predetermined route based on navigation data. The controller is further programmed to, in response to the electric machine operating to propel the vehicle over the predetermined route while the engine is shutdown and an upcoming increase in the powertrain power output profile to a value that is greater than a threshold, initiate an engine start at a predetermined time period before the upcoming increase in the powertrain power output profile.