Hybrid Powertrain NOx Control via Closed-Loop Feedback
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Solution Overview
Problem
Hybrid powertrain systems face challenges in efficiently controlling NOx emissions and combustion noise while generating torque, as existing systems lack effective closed-loop control routines to dynamically manage engine operations in response to desired output torque and noise setpoints.
Innovation Solution
The system includes determining desired output torque and setpoints for NOx emissions and combustion noise, with closed-loop control routines to adjust engine EGR flow and start of injection timing, using PID controllers to dynamically control engine operations, ensuring the internal combustion engine and electric machine work together to achieve these setpoints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the engine operates at desired output torque without closed-loop control, then torque generation is maintained, but NOx emissions and combustion noise cannot be precisely controlled
Solution Approach 1:
The patent implements closed-loop control routines that continuously monitor engine-out NOx emissions and combustion noise, comparing measured values against setpoints. The control system dynamically adjusts EGR flow and start of injection timing based on feedback from sensors, enabling precise control of harmful emissions and noise while maintaining desired torque output.
2Measurement precision
If closed-loop control routines are implemented to control NOx emissions, then emission precision is improved, but control system complexity increases
Solution Approach 1:
The control system employs feedback mechanisms where engine-out NOx emissions are dynamically measured and compared against a setpoint. The difference between measured emissions and the setpoint drives adjustments in EGR flow and injection timing through PID control routines, achieving precise emissions control.
Solution Approach 2:
The patent dynamically changes engine operating parameters including EGR flow rate and start of injection timing based on real-time emissions measurements. By adjusting these parameters in response to feedback, the system achieves precise control of NOx emissions while adapting to varying operating conditions.
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 approach allows for precise control of NOx emissions and combustion noise, enhancing engine efficiency and reducing fuel consumption by optimizing engine operation in hybrid powertrain systems, while maintaining transparency and reducing tailpipe emissions.
Implementation Method 1
supplying an amount of fuel to the internal combustion engine to generate torque in response to the engine torque command
Implementation Method 2
executing a first closed-loop control routine to control the EGR flow based upon the engine out NOx emissions and the engine-out NOx setpoint
Data Source
AI summary
A powertrain system including an internal combustion engine and an electric machine that are configured to generate torque that is transferred via a geartrain to a vehicle driveline is described. A method for controlling the powertrain system includes determining a desired output torque, and determining an engine torque command and an electric machine torque command based upon the desired output torque. An engine-out NOx setpoint associated with operating the engine at the desired output torque is determined. The electric machine is operated in response to the electric machine torque command. The engine is operated to generate torque in response to the engine torque command and engine operation is controlled to achieve the engine-out NOx setpoint.