Hybrid Vehicle Exhaust Oxygen Control for Torque Compensation
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Solution Overview
Problem
Existing engine control systems face a tendency for insufficient engine torque when the air-fuel ratio becomes too rich, leading to a decrease in fuel injection amount, which can result in an excessively small air-fuel ratio.
Innovation Solution
A controller that acquires oxygen concentration from the engine exhaust and adjusts the fuel injection amount and electric driving force to prevent insufficient torque while maintaining an appropriate air-fuel ratio, by reducing fuel injection when oxygen concentration is low and increasing electric driving force accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the injection amount from the injector is reduced to bring the air-fuel ratio close to the stoichiometric air-fuel ratio, then the air-fuel ratio is improved, but the engine torque becomes insufficient
Solution Approach 1:
The patent combines the engine driving force with an electric motor to form a hybrid power system. When the air-fuel ratio needs adjustment, the electric motor compensates for the torque deficiency caused by reduced fuel injection, thereby maintaining both precise air-fuel ratio control and sufficient engine torque output.
Solution Approach 2:
The system dynamically changes the operating parameters by introducing an electric motor that can independently adjust its output torque. This allows the system to decouple the relationship between fuel injection amount and torque output, enabling precise air-fuel ratio control without sacrificing torque requirements.
2Reliability
If the injection amount is decreased to prevent excessively small air-fuel ratio, then the air-fuel ratio is maintained, but the engine torque becomes insufficient
Solution Approach 1:
The system employs feedback control where the air-fuel ratio sensor continuously monitors the actual air-fuel ratio and sends signals to the controller. The controller adjusts the injection amount to maintain the desired air-fuel ratio, while the electric motor provides compensatory torque to ensure power requirements are met, creating a closed-loop control system that balances both objectives.
Solution Approach 2:
The electric motor acts as an intermediary between the fuel injection system and the torque output requirement. It mediates the conflict by providing additional torque when fuel injection is reduced for air-fuel ratio control, thereby shielding the torque output from the effects of reduced fuel injection.
Data Source
AI summary
A vehicle includes: an acquisition part that acquires the oxygen concentration of exhaust from an engine mounted on the vehicle that can travel on an electric driving force generated by an electric motor and an engine driving force generated by the engine; and a drive control part that reduces an injection amount of fuel injected into a cylinder of the engine and increases the electric driving force, from among the engine driving force and the electric driving force for propelling the vehicle, in the case where the oxygen concentration is lower than an oxygen threshold value in comparison to the case where the oxygen concentration is equal to or higher than the oxygen threshold value.