The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Vehicles typically include a powerplant and transmission that transmits drive torque at various gear ratios or ranges to a drivetrain. Typically, the transmission includes a geartrain that transmits drive torque input to the transmission at the various gear ratios or ranges. Automatic transmissions include one or more hydraulically-actuated mechanisms, such as a friction clutch, that selectively couple various components of the geartrain and thereby vary the gear ratio at which the drive torque is transmitted.
Transmission control systems have been developed to control transmission operation, including the clutches used to operate the transmission in the various gear ratios. Clutch control systems may achieve a shift by disengaging one or more engaged clutches, referred to as off-going clutches, while engaging one or more disengaged clutches, referred to as on-coming clutches. The clutch control systems may engage the disengaged clutches based on expected response times. However, when actual response times lag the expected response times, the disengaged clutches may not engage as soon as desired. Delays in the expected response times may result in objectionable shift feel. For example, the delays may cause objectionable surges or sags in vehicle acceleration during down shifts and/or objectionable surges or sags in vehicle acceleration during an up shift.