Hybrid Vehicle Engine Operating Point Selection
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Solution Overview
Problem
Hybrid electric vehicles face inefficiencies in powertrain operation, particularly when in Park or Neutral gear, as existing systems struggle to optimize engine speed and torque to maximize combined efficiency of the engine and electric machine while minimizing fuel consumption and losses.
Innovation Solution
A method is implemented to control the engine and electric machine in hybrid vehicles by using an upstream clutch and a step ratio transmission gearbox, where the engine speed and torque are determined based on the electric machine's power generation request, optimizing powertrain efficiency by minimizing losses and considering factors like altitude and noise, vibration, and harshness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the engine operates at fixed speed and torque in Park or Neutral gear, then the control system is simple, but powertrain efficiency is reduced and fuel consumption increases
Solution Approach 1:
The patent implements dynamic engine speed and torque adjustment based on real-time powertrain conditions. The controller continuously calculates optimal operating points and adjusts engine parameters dynamically, transforming the static fixed-speed operation into a dynamic optimization system that adapts to changing conditions while maintaining efficiency.
Solution Approach 2:
The system changes engine operating parameters (speed and torque) based on calculated optimal values. By continuously adjusting these parameters according to powertrain efficiency requirements, the system resolves the contradiction between simple control and efficient operation.
2Device complexity
If the engine operates at fixed speed and torque in Park or Neutral gear, then the control system is simple, but fuel consumption increases
Solution Approach 1:
The system dynamically adjusts engine speed and torque based on real-time conditions rather than maintaining fixed operation. This dynamic control optimizes fuel consumption by operating the engine at efficient points while adapting to changing powertrain requirements.
Solution Approach 2:
The controller uses feedback from powertrain conditions to continuously adjust engine operating parameters. By monitoring and responding to system state changes, the feedback mechanism enables fuel-efficient operation without requiring complex manual intervention.
3Use of energy by moving object
If the engine operates at optimized speed and torque for powertrain efficiency, then fuel consumption is reduced, but the control and calculation complexity increases
Solution Approach 1:
The system performs self-optimization by automatically calculating and adjusting its own operating parameters. The controller independently determines optimal engine speed and torque based on powertrain conditions, eliminating the need for external intervention while maintaining efficiency.
Solution Approach 2:
The patent replaces complex mechanical control mechanisms with electronic calculation and control. By using computational methods to determine optimal operating points and electronic actuators to implement adjustments, the system achieves efficiency optimization with manageable control complexity.
4Loss of energy
If the engine speed and torque are optimized for powertrain efficiency, then losses in the powertrain are minimized, but the system must continuously calculate and adjust operating points increasing control complexity
Solution Approach 1:
The control system automatically monitors powertrain conditions and self-adjusts operating parameters to minimize losses. This self-service capability reduces energy losses while managing control complexity through autonomous operation without external intervention.
Solution Approach 2:
The system replaces complex mechanical loss-reduction mechanisms with electronic control and calculation. By using computational optimization and electronic actuation, the system achieves loss minimization with manageable control system complexity.
Data Source
AI summary
A vehicle includes a powertrain having an engine and an electric machine (M/G) connected by an upstream clutch, and a gearbox connected to the M/G by a torque converter. A controller is configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the engine at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency. A method is provided for controlling a vehicle. In response to a Park or Neutral gear selection and an electrical power request from the M/G, the engine is operated at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency.