Hybrid Vehicle Control System for Emission Reduction and Battery Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid vehicle control systems fail to effectively reduce exhaust gas during deceleration and properly protect the motor-generator and battery, leading to issues like overheating and overcharging.
Innovation Solution
A control system for hybrid vehicles that selects between low-power and high-power modes based on the state of charge of the electric storage device and acceptable input power, using the first motor to control engine speed and the second motor to generate brake torque, thereby reducing engine torque and power at optimized rates to minimize emissions and prevent overcharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the throttle valve is closed completely to reduce engine torque to zero during deceleration, then the engine torque is reduced, but the air intake is reduced abruptly causing increased exhaust gas
Solution Approach 1:
The patent applies dynamics by transitioning the throttle valve control from a static closed state to a dynamic gradual closure process. The throttle valve is controlled to close gradually rather than abruptly, allowing the air intake to decrease progressively during deceleration. This dynamic control prevents sudden changes in air intake that would cause incomplete combustion and increased exhaust gas emissions.
Solution Approach 2:
The patent changes the parameter of throttle valve opening degree from a binary state (fully open or fully closed) to a continuous variable that can be adjusted gradually. By controlling the throttle valve to close at a predetermined gradual rate, the air intake parameter changes smoothly during deceleration, preventing abrupt reductions that lead to increased exhaust gas.
2Object-generated harmful factors
If the engine torque is reduced rapidly during deceleration, then the exhaust gas is reduced, but the motor-generator and battery may not be protected properly causing overheating and overcharging
Solution Approach 1:
The patent implements feedback control by monitoring the state of the motor-generator and battery during deceleration. The control system adjusts the engine torque reduction rate based on the actual condition of the motor-generator and battery, ensuring they are protected from overheating and overcharging while still reducing exhaust gas emissions effectively.
Solution Approach 2:
The patent applies dynamics by making the torque reduction rate adjustable rather than fixed. The control system dynamically adjusts the engine torque reduction rate based on real-time conditions of the motor-generator and battery, allowing for optimized protection while maintaining emission reduction goals.
3Speed
If the lock-up clutch control mode is shifted immediately during deceleration, then the engine speed control is responsive, but the engine torque may be raised abruptly generating shock
Solution Approach 1:
The patent applies preliminary action by preparing the throttle valve for gradual closure before the lock-up clutch control mode is shifted. This preliminary control of the throttle valve ensures that engine torque is already being reduced in a controlled manner, preventing abrupt torque increases when the clutch control mode changes during deceleration.
Solution Approach 2:
The patent uses the throttle valve as an intermediary mechanism to mediate between the lock-up clutch control and the engine torque output. By controlling the throttle valve to close gradually, it acts as a buffer that prevents abrupt changes in engine torque when the lock-up clutch control mode is shifted, thereby reducing shock.
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
The system effectively reduces emissions during deceleration, protects the motor-generator and battery by optimizing engine power reduction, and prevents overcharging by adjusting control modes based on battery state and power conditions.
Implementation Method 1
a second motor (MG2) that applies a brake torque to drive wheels when regenerating energy
Implementation Method 2
a first motor (MG1) that controls a speed of the engine
Data Source
AI summary
A control system for a hybrid vehicle configured to reduce an exhaust gas during deceleration of the vehicle, and to protect a motor and a battery. A control mode of the engine may be selected from: a low-power mode in which the hybrid vehicle is decelerated by reducing a torque and a power of the engine at a predetermined rate while generating the brake torque by the motor; and a high-power mode in which the hybrid vehicle is decelerated by reducing the torque and the power of the engine at a rate slower than the predetermined rate of the low-power mode while generating the brake torque by the motor.