Hybrid Powertrain Control for Park Neutral Feedback
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Solution Overview
Problem
In hybrid electric vehicles, existing control systems fail to provide intuitive and fuel-efficient engine management when the vehicle is in Park or Neutral, as the engine is often disabled to prevent wasted output, leading to a lack of feedback and inefficient power distribution.
Innovation Solution
A control method that engages the engine and electric machine via a clutch, allowing speed control of the electric machine based on accelerator pedal depression, and starts the engine when necessary, regardless of battery state of charge, to maintain responsiveness and conserve fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the engine is disabled while the vehicle is in Park or Neutral to prevent wasted output, then fuel economy is improved, but driver feedback response is lost
Solution Approach 1:
The system dynamically switches between engine disabled and engine running states based on accelerator pedal depression. When the pedal is depressed beyond a threshold, the engine transitions from disabled to running state, providing feedback while maintaining fuel economy during normal Park/Neutral operation.
Solution Approach 2:
The control system changes the operational parameters of the engine based on accelerator pedal position. By monitoring pedal depression threshold and adjusting engine state accordingly, the system optimizes the balance between fuel consumption and driver feedback.
2Ease of operation
If the engine is started in response to accelerator pedal depression beyond a threshold, then driver feedback is improved, but fuel consumption increases
Solution Approach 1:
The system performs preliminary assessment of accelerator pedal depression before starting the engine. By setting a depression threshold, the system determines whether engine start is necessary, avoiding unnecessary fuel consumption while ensuring feedback is provided when truly needed.
3Speed
If the electric machine speed is controlled based on accelerator pedal depression rate, then vehicle responsiveness is enhanced, but control complexity increases
Solution Approach 1:
The control system implements feedback by monitoring accelerator pedal depression rate and adjusting electric machine speed accordingly. This creates a responsive control loop that enhances vehicle responsiveness while using straightforward sensor-input and actuator-output relationships.
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 solution ensures intuitive driver feedback and efficient power distribution by controlling the electric machine's speed and engine torque, reducing fuel waste and enhancing the vehicle's responsiveness while in Park or Neutral.
Implementation Method 1
an internal combustion engine that is selectively coupled to an electric machine such that torque output by the engine is converted to electric power by the electric machine
Data Source
AI summary
A hybrid vehicle includes an engine and an electric machine selectively coupled to the engine via a clutch. The engine, electric machine, and clutch are arranged along a common axis. At least one controller is programmed to execute various commands when the vehicle is in park or neutral and the accelerator pedal of the vehicle is depressed. This enhances perceived vehicle reactions in response to accelerator pedal movement. To do so, the controller is programmed to control a rate of speed increase of the electric machine based on a rate of the depression of the accelerator pedal (e.g., “speed control”). Furthermore, the torque output of the engine is controlled to a target value irrespective of engine speed and engine torque is converted into electric energy via the electric machine (e.g., “torque control”). The rate of speed increase of the electric machine is altered when the engine is started.