Vehicle Control Apparatus Managing Engine Torque During Deceleration
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Solution Overview
Problem
Existing vehicle control systems face challenges in managing engine fuel cut and restart during decelerated travel, leading to increased fuel consumption and potential excessive engine torque, which can reduce vehicle deceleration rates and cause discomfort to occupants.
Innovation Solution
A vehicle control apparatus that includes an engine, refrigerant compressor, lock up clutch, and throttle valve, controlled by multiple deceleration controllers to manage the engine's fuel cut and restart states, optimizing engine speed and torque through strategic control of the lock up clutch and throttle valve positions based on vehicle speed and compressor operation states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the engine is controlled to fuel cut state on decelerated travel, then fuel consumption is reduced, but engine speed may lower to excessive levels causing restart of fuel injection
Solution Approach 1:
The lock up clutch is engaged in advance before engine speed drops to the lower limit, and the throttle valve is opened to increase intake air amount. These preliminary actions prevent engine speed from dropping too low, ensuring that fuel injection can be maintained in cut state without premature restart.
Solution Approach 2:
The system changes the throttle plate position parameter by opening the throttle valve during deceleration with fuel cut. This increases the intake air amount, which helps maintain engine speed within the range where fuel cut can be sustained, thereby extending the fuel cut duration.
2Reliability
If fuel injection is restarted when engine speed reaches lower limit, then engine speed is maintained, but excessive engine torque is generated reducing vehicle deceleration rate
Solution Approach 1:
The throttle valve is opened in advance before engine speed reaches the lower limit during deceleration. This preliminary action increases intake air amount, allowing the engine to maintain speed without restarting fuel injection, thereby avoiding excessive torque generation and maintaining optimal vehicle deceleration.
Solution Approach 2:
The control system continuously monitors engine speed and vehicle deceleration rate, using this feedback to determine the optimal timing for throttle valve operation and fuel injection restart, balancing engine speed maintenance with vehicle deceleration performance.
3Speed
If the throttle valve is controlled closewise during deceleration, then engine braking is enhanced, but engine speed drops rapidly causing premature fuel injection restart
Solution Approach 1:
The throttle valve is opened in advance before engine speed drops to critical levels. This preliminary opening of the throttle prevents rapid engine speed drop that would otherwise occur with closewise throttle control, allowing the vehicle to maintain optimal deceleration while sustaining fuel cut state.
Solution Approach 2:
The throttle valve position is dynamically adjusted during deceleration based on real-time engine speed and vehicle deceleration conditions. Instead of being fixed in a closewise position, the throttle plate position varies to optimize the balance between vehicle deceleration rate and fuel cut duration.
Data Source
AI summary
A vehicle control apparatus includes an engine, a refrigerant compressor, a lock up clutch, a throttle valve, and first, second, and third deceleration controllers. The second deceleration controller controls the lock up clutch to a slip state and controls the throttle valve openwise on the condition that the refrigerant compressor is in the stopped state on decelerated travel of a vehicle in a second speed region in which a vehicle speed is lower than a first vehicle speed and higher than a second vehicle speed lower than the first vehicle speed. The second deceleration controller controls the lock up clutch to a disengaged state and controls the throttle valve closewise on the condition that the refrigerant compressor is in the operative state on the decelerated travel of the vehicle in the second speed region.