Vehicle Generator Voltage Control During Deceleration Gear Shifts
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Solution Overview
Problem
The integration of gear change control with lock-up clutch control and power generation control in vehicles during deceleration can lead to inappropriate execution of lock-up clutch control due to changes in engine torque, affecting fuel economy and stability.
Innovation Solution
A control apparatus and method that maintains a constant generated voltage during upshift gear change control and increases it at a specified rate during downshift gear change control, while ensuring the lock-up clutch control is executed appropriately, thereby preventing changes in engine torque from influencing the clutch control and optimizing regenerative electric power generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If gear change control is added to lock-up clutch control and power generation control during vehicle deceleration, then regenerative electric power generation is improved, but lock-up clutch control cannot be executed appropriately due to engine torque changes
Solution Approach 1:
The control apparatus predicts the timing of gear change in advance and switches the alternator output voltage to high voltage before the gear change occurs. This preliminary action ensures that the lock-up clutch control is not influenced by voltage switching during gear change, while still enabling regenerative power generation after the gear change is complete
Solution Approach 2:
The control apparatus dynamically adjusts the alternator output voltage based on the gear change state. During upshift gear change, the voltage is maintained constant; during downshift gear change, the voltage is increased at a specified rate. This dynamic adjustment allows the system to optimize regenerative power generation while maintaining appropriate lock-up clutch control under different operating conditions
2Use of energy by moving object
If the output voltage of the alternator is switched to high voltage during deceleration, then regenerative electric power amount is increased, but this switching may influence the lock-up clutch control
Solution Approach 1:
The alternator output voltage is switched to high voltage in advance before the gear change occurs, based on predicted timing. This ensures that the voltage switching does not coincide with lock-up clutch control execution, preventing interference while maximizing regenerative power generation
Solution Approach 2:
The control apparatus dynamically adjusts the alternator output voltage based on real-time gear change detection. During upshift, voltage is held constant during gear change; during downshift, voltage is increased at a controlled rate. This dynamic control separates voltage switching from lock-up clutch control timing
3Use of energy by moving object
If the generated voltage is increased during downshift gear change control, then regenerative electric power generation is optimized, but engine torque changes may affect lock-up clutch control
Solution Approach 1:
During downshift gear change control, the generated voltage is increased at a specified rate rather than immediately to the target value. This controlled dynamic adjustment allows regenerative power generation to be optimized while preventing sudden engine torque changes that would interfere with lock-up clutch control execution
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
This approach allows for appropriate execution of lock-up clutch control even when gear change control is added to lock-up clutch and power generation control, improving fuel economy by generating regenerative electric power without interfering with the clutch control and stabilizing engine speed.
Implementation Method 1
The generator is configured to be driven by drive power of the engine to generate electric power
Data Source
AI summary
A control apparatus for a vehicle includes an electronic control unit that is configured to set a value of a target generated voltage of the generator. The electronic control unit is configured to execute power generation control to control a generated voltage of a generator. The electronic control unit is configured to maintain a value of the generated voltage in the power generation control to be constant during an upshift gear change when the upshift gear change control of a transmission is executed while the lock-up clutch control is executed during deceleration of the vehicle. The electronic control unit is configured to increase the value in the power generation control during the downshift control to the value of the target generated voltage at a first specified rate when a downshift gear change of the transmission is executed while the lock-up clutch control is executed during the deceleration.