Hybrid Drive Clutch Pressure Learning Under Input Shaft Constraint

The patent applies dynamics by transitioning the speed change mechanism from a static state (P range or N range) to a dynamic state (engagement range) where the input member is constrained to rotate only when the friction engagement element actually engages. This dynamic approach allows the system to eliminate unwanted rotation during learning while maintaining the ability to measure torque changes at engagement.

The patent changes the operational parameter of the speed change mechanism from parking/neutral range to engagement range. This parameter change ensures that the input member remains stationary during the learning process until the friction engagement element engages, thereby eliminating drag torque-induced rotation and enabling accurate measurement of torque changes for learning the engagement start pressure.

The patent converts the harmful drag torque effect into a beneficial measurement signal. By placing the speed change mechanism in engagement range, the drag torque that would normally cause unwanted rotation instead becomes the very torque that must be overcome for engagement to occur. This allows the system to use the drag torque itself as part of the measurement process for learning engagement start pressure.

The patent changes the speed change mechanism's operational state from P range or N range to engagement range. This parameter change eliminates the harmful effect of drag torque-induced rotation by ensuring the input member is constrained, while simultaneously enabling the system to measure the torque required to overcome drag and achieve engagement.

The patent applies universality by making the learning control method applicable to both the engine connection clutch and the starting clutch through a single unified approach. By placing the speed change mechanism in engagement range, the same learning procedure can accurately learn engagement start pressure for either clutch type, eliminating the need for separate learning procedures and improving measurement accuracy for the starting clutch.

The patent changes the speed change mechanism's operational parameter to engagement range, which enables the learning control to be universally applied to both clutches. This parameter change ensures that the input member remains stationary during learning, allowing accurate measurement of torque changes for learning the starting clutch's engagement start pressure, thereby achieving both adaptability and precision.