Hybrid Vehicle Control Reducing Re-acceleration Delay
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Solution Overview
Problem
Hybrid vehicles experience response delays and one-way clutch engagement shocks due to the undesired stopping of power sources during coasting, leading to inefficient fuel usage and delayed acceleration when re-accelerating.
Innovation Solution
A hybrid vehicle control apparatus that controls the rotational speed of the motor/generator to equalize the rotational speeds of the input and output sides of the one-way clutch during coasting, allowing for smoother re-acceleration by transitioning from rotational speed control to torque control, thereby reducing response delays and engagement shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the power sources (engine and motor/generator) are stopped during coasting to improve fuel efficiency, then fuel efficiency is improved, but response delay occurs when re-accelerating
Solution Approach 1:
The control apparatus performs preliminary action by maintaining the rotational speed of the one-way clutch input side during coasting, so that when acceleration is requested, the clutch can engage immediately without delay. This is achieved by controlling the motor/generator to maintain the rotational speed difference between input and output sides of the one-way clutch within a predetermined range, preparing the system in advance for potential re-acceleration.
2Use of energy by moving object
If the power sources are stopped during coasting, then fuel efficiency is improved, but one-way clutch engagement shock occurs during re-acceleration
Solution Approach 1:
The control apparatus prepares the system in advance by maintaining the rotational speed of the one-way clutch input side during coasting, ensuring that when acceleration is requested, the clutch engages smoothly without shock. The rotational speed is controlled to be within a predetermined range of the output side rotational speed, preventing sudden engagement shocks.
Solution Approach 2:
The control apparatus cushions against potential engagement shocks by maintaining a controlled rotational speed difference during coasting. By keeping the input side rotational speed within a predetermined range of the output side rotational speed, the system prepares a cushioning effect that prevents sudden shocks when the clutch engages during re-acceleration.
3Device complexity
If the rotational speed of the one-way clutch input side is not controlled during coasting, then the system is simpler, but re-acceleration performance deteriorates
Solution Approach 1:
The control apparatus uses feedback control to maintain the rotational speed of the one-way clutch input side within a predetermined range of the output side rotational speed during coasting. The control unit continuously monitors the rotational speeds and adjusts the motor/generator output to maintain the desired speed relationship, ensuring optimal re-acceleration performance without excessive complexity.
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 solution effectively reduces re-acceleration delays and engagement shocks, improving the vehicle's responsiveness and fuel efficiency by ensuring seamless power transmission from the motor/generator during re-acceleration.
Implementation Method 1
a motor/generator (1) arranged between the engine (2) and the transmission (4)
Implementation Method 2
power from the engine and/or the motor/generator is transmitted through a one-way clutch such that physical shock resulting from gear shifting can be eliminated
Implementation Method 3
a first clutch (6) with a variable torque transmission capacity being disposed between the engine (2) and the motor/generator (1)
Data Source
Figure 1
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AI summary
A hybrid vehicle control apparatus is provided with a motor/generator (1) arranged between an engine (2) and a transmission (4), a first clutch (6) disposed between the engine (2) and the motor/generator (1), a second clutch (7) disposed in a power train spanning from the motor/generator (1) to a drive wheel (3L,3R), and a controller (20). The controller (20) controls the engagement of the first (6) and second (7) clutches to select either an electric drive mode or a hybrid drive mode. The controller (20) executes a rotational speed control of the motor/generator (1) while in a coasting state with torque being transmitted through a one-way clutch (4c) of the transmission (4) such that the rotational speed control increases an input rotational speed of the one-way clutch (4c) to a value closer to an output rotational speed of the one-way clutch (4c) with a difference between the input and output rotational speeds of the one-way clutch (4c) becoming equal to a target value.