Vehicle Motor Speed Control for Fuel Efficiency
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Solution Overview
Problem
Conventional vehicle control methods fail to optimize fuel efficiency when the motor/generator is driven while the vehicle is stopped, leading to inefficiencies.
Innovation Solution
A vehicle control method that keeps the friction clutch disengaged with eliminated slack, reduces motor rotational speed using a predetermined speed as a target when stopping the motor/generator, and limits torque to improve fuel efficiency by stopping the motor/generator when the vehicle is stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the motor/generator is driven while the vehicle is stopped, then the vehicle can maintain readiness for acceleration, but fuel efficiency deteriorates
Solution Approach 1:
The motor rotational speed is dynamically adjusted based on vehicle conditions. During vehicle stoppage, the motor rotational speed is reduced from idle speed toward zero, allowing the system to transition from a static idle state to a dynamic stopped state, thereby improving fuel efficiency while maintaining acceleration capability when needed
Solution Approach 2:
The invention changes the operational parameters of the motor/generator by reducing rotational speed and limiting torque output during vehicle stoppage. This parameter change allows the motor to operate more efficiently or remain stopped, directly addressing the fuel efficiency issue while maintaining system readiness
2Loss of time
If the friction clutch is engaged to stop the motor/generator quickly, then stoppage time is reduced, but vehicle shock increases
Solution Approach 1:
The invention applies beforehand cushioning by limiting the torque output of the motor/generator before and during the stoppage process. This torque limitation prevents sudden torque changes that would cause vehicle shock, while the friction clutch remains engaged to provide mechanical connection for quick stoppage when needed
Solution Approach 2:
The friction clutch acts as an intermediary element between the motor/generator and the drive wheels. By keeping the clutch engaged with eliminated slack, it provides a mechanical connection that enables quick stoppage while the torque limitation serves as a mediator to prevent shock transmission to the vehicle
3Ease of operation
If the friction clutch has slack in the stroke, then engagement is smoother, but engagement response delay increases
Solution Approach 1:
The invention applies preliminary action by eliminating slack in the friction clutch stroke in advance, before engagement is needed. This preliminary adjustment ensures that when the clutch needs to engage, it can do so immediately without delay, while the torque limitation provides the smoothness during the engagement process
Data Source
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AI summary
A friction clutch of a vehicle is maintained disengaged with slack in the stroke eliminated, while the vehicle is stopped; in response to a request to stop a motor/generator, if the motor rotational speed of the motor/generator is greater than a predetermined rotational speed, the motor rotational speed is reduced using the predetermined rotational speed as a target motor rotational speed, and when the motor rotational speed has reached the predetermined rotational speed, the motor rotational speed is reduced toward zero, while a limit is placed on the torque of the motor/generator.