Electric Differential Control for Vehicle Power Transmission
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Solution Overview
Problem
The existing power transmission apparatus for vehicles with electric differential portions experiences a decrease in starting and stopping performance, and deterioration of noise/vibration characteristics when the shift position is changed from parking to neutral, especially during load operations or engine starting/stopping.
Innovation Solution
A control apparatus and method that controls the rotational speed of the output shaft of the electric differential portion to a predetermined speed during shifts from parking to neutral, ensuring continuous control until starting or stopping operations are completed, and maintaining this control until load changes are finished to prevent rotational speed fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the shift position is changed from parking to neutral while the main power source is being started or stopped, then the shift operation is completed, but the starting performance and stopping performance of the main power source decrease
Solution Approach 1:
The control apparatus detects when a shift position change is initiated during main power source starting or stopping operations, and preemptively maintains the fixing control of the output shaft throughout the shift operation. This preliminary detection and continuous control strategy ensures that the starting/stopping performance is preserved while still allowing the shift operation to proceed.
Solution Approach 2:
The fixing control of the output shaft using the second motor is maintained continuously throughout the entire shift operation duration, rather than being interrupted. This continuous control action ensures uninterrupted starting/stopping performance while the shift from parking to neutral position is executed.
2Speed
If the shift position is changed from parking to neutral while the load operation of the main power source is being performed, then the shift operation is completed, but the rotational speed of the main power source fluctuates and noise/vibration characteristics deteriorate
Solution Approach 1:
The control apparatus detects when a shift position change is initiated during load operations of the main power source, and preemptively maintains the fixing control of the output shaft throughout the shift operation. This preliminary detection and continuous control strategy prevents rotational speed fluctuations and associated noise/vibration before they can occur.
Solution Approach 2:
The fixing control of the output shaft using the second motor is maintained continuously throughout the entire shift operation duration during load operations, rather than being interrupted. This continuous control action ensures stable rotational speed and prevents noise/vibration deterioration while the shift from parking to neutral position is executed.
Data Source
AI summary
A control apparatus for a power transmission apparatus for a vehicle controls the rotational speed of an output shaft of an electric differential portion to a predetermined rotational speed until at least one of a control that starts a main power source and a control that stops the main power source ends, if at least one of a shift position and a shift range is changed from a parking position to a neutral position while the at least one of the control that starts the main power source and the control that stops the main power source is being executed.