Abstract: A powertrain system including an internal combustion engine rotatably coupled to a continuously variable transmission (CVT) is described. A method for controlling the CVT includes determining minimum and maximum CVT input speeds in response to an accelerator pedal position, and monitoring vehicle speed and a CVT input speed. A target CVT input acceleration rate is determined based upon the vehicle speed, and a desired speed ratio is determined that is responsive to the target CVT input acceleration rate. The CVT is controlled based upon the desired speed ratio.

Abstract: A target ratio module selectively determines a target ratio of transmission input shaft speed to transmission output shaft speed independently of an accelerator pedal position and as a function of a vehicle speed and a driver axle torque request. A first pulley valve control module controls opening of a first valve based on the target ratio. The first valve controls transmission fluid flow to a first pulley actuator. The first pulley actuator is coupled to the transmission input shaft of a continuously variable transmission (CVT) and expands and contracts based on transmission fluid pressure. A second pulley valve control module controls opening of a second valve based on the target ratio. The second valve controls transmission fluid flow to a second pulley actuator. The second pulley actuator is coupled to the transmission output shaft of the CVT and expands and contracts based on transmission fluid pressure.

Abstract: A powertrain system including an internal combustion engine rotatably coupled to a continuously variable transmission (CVT) is described. A method for controlling the CVT includes determining minimum and maximum CVT input speeds in response to an accelerator pedal position, and monitoring vehicle speed and a CVT input speed. A target CVT input acceleration rate is determined based upon the vehicle speed, and a desired speed ratio is determined that is responsive to the target CVT input acceleration rate. The CVT is controlled based upon the desired speed ratio.

Abstract: A target ratio module selectively determines a target ratio of transmission input shaft speed to transmission output shaft speed independently of an accelerator pedal position and as a function of a vehicle speed and a driver axle torque request. A first pulley valve control module controls opening of a first valve based on the target ratio. The first valve controls transmission fluid flow to a first pulley actuator. The first pulley actuator is coupled to the transmission input shaft of a continuously variable transmission (CVT) and expands and contracts based on transmission fluid pressure. A second pulley valve control module controls opening of a second valve based on the target ratio. The second valve controls transmission fluid flow to a second pulley actuator. The second pulley actuator is coupled to the transmission output shaft of the CVT and expands and contracts based on transmission fluid pressure.

Abstract: A method and system for controlling movement of an actuator fork of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity includes adjusting the level of fluid pressure applied to an actuator operatively attached to the actuator fork to control the pre-synchronization fork velocity within a predetermined range of a velocity target. The method determines, via a controller, the fork velocity during the pre-synchronization phase of a current synchronization event, compares the determined fork velocity to a velocity target, and adjusts the pressure level of fluid applied to an actuator piston of the actuator to control the velocity of the actuator fork within a predetermined range defined by the velocity target during a subsequent pre-synchronization phase. The velocity target may be defined for a shift type, such as a fast or slow shift, where the shift type is determined by the controller.

Abstract: A vehicle includes an engine, a transmission having a position-controlled clutch with a synchronizer sleeve and a synchronizer fork, an input member with an input speed, and an output member with an output speed, and a controller. The controller is programmed to register a slip-away condition when the input speed falls within a calibrated speed band and the output speed remains below a calibrated threshold speed. In response to the registered slip-away condition, the controller records a diagnostic code indicative of the synchronizer sleeve being disengaged, changes an engaged position of the synchronizer sleeve by a calibrated amount to thereby adapt the engaged position, and commands the clutch to disengage and the fork to move to a neutral position after increasing the engaged position. The controller also moves the synchronizer sleeve toward the adapted engaged position and applies the clutch when the synchronizer sleeve attains the adapted engaged position.

Abstract: A method of controlling movement of an actuator fork and attached synchronizer sleeve of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity below a breakaway velocity such that a strut is retained to the sleeve by a ball plunger for the duration of the pre-synchronization phase. A method of adjusting one of a pressure signal and a flow signal to an actuator piston to control movement of the actuator fork includes moving the fork from an initial disengaged position through a pre-synchronization phase of a synchronization event by controlling one of a pre-synchronization fluid pressure value and flow value, where the controlled pre-synchronization fluid value is less than a threshold value corresponding to a breakaway force of a ball plunger configured to selectively retain a strut assembly to a synchronizer sleeve operatively attached to the actuator fork.

Abstract: A method and system for controlling movement of an actuator fork of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity includes adjusting the level of fluid pressure applied to an actuator operatively attached to the actuator fork to control the pre-synchronization fork velocity within a predetermined range of a velocity target. The method determines, via a controller, the fork velocity during the pre-synchronization phase of a current synchronization event, compares the determined fork velocity to a velocity target, and adjusts the pressure level of fluid applied to an actuator piston of the actuator to control the velocity of the actuator fork within a predetermined range defined by the velocity target during a subsequent pre-synchronization phase. The velocity target may be defined for a shift type, such as a fast or slow shift, where the shift type is determined by the controller.

Abstract: A method of controlling a transmission includes selecting a target speed of a second shaft, and measuring a second speed of the second shaft and an output speed of an output shaft. The method includes detecting a rolling neutral condition wherein a first and second clutch are uncoupled from a torque generator and a synchronizer is mated to a predicted gear to apply a load in a direction, and one of a first condition wherein the output speed is decreasing and the target speed is less than the second speed and a second condition wherein the output speed is increasing and the target speed is less than the second speed. The method then includes translating the synchronizer away from the predicted gear, coupling and decoupling the second clutch to and from the torque generator, and mating the synchronizer to the predicted gear to again apply the load in the direction.

Abstract: A method of controlling a transmission includes selecting a target speed of a second shaft, and measuring a second speed of the second shaft and an output speed of an output shaft. The method includes detecting a rolling neutral condition wherein a first and second clutch are uncoupled from a torque generator and a synchronizer is mated to a predicted gear to apply a load in a direction, and one of a first condition wherein the output speed is decreasing and the target speed is less than the second speed and a second condition wherein the output speed is increasing and the target speed is less than the second speed. The method then includes translating the synchronizer away from the predicted gear, coupling and decoupling the second clutch to and from the torque generator, and mating the synchronizer to the predicted gear to again apply the load in the direction.

Abstract: A method of controlling movement of an actuator fork and attached synchronizer sleeve of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity below a breakaway velocity such that a strut is retained to the sleeve by a ball plunger for the duration of the pre-synchronization phase. A method of adjusting one of a pressure signal and a flow signal to an actuator piston to control movement of the actuator fork includes moving the fork from an initial disengaged position through a pre-synchronization phase of a synchronization event by controlling one of a pre-synchronization fluid pressure value and flow value, where the controlled pre-synchronization fluid value is less than a threshold value corresponding to a breakaway force of a ball plunger configured to selectively retain a strut assembly to a synchronizer sleeve operatively attached to the actuator fork.

Abstract: A method of identifying a synchronous position of a synchronizer actuator fork includes sensing a deceleration rate of a first shaft, when a synchronizer is positioned in a neutral position, to define a first rate of deceleration. The synchronizer is moved along the first shaft from the neutral position toward a gear with a synchronizer actuator fork. A deceleration rate of the first shaft is sensed, while the synchronizer actuator fork moves the synchronizer along the first shaft, to identify a change from the first rate of deceleration to a second rate of deceleration. The location, of the synchronizer actuator fork relative to the first shaft, at which the rate of acceleration of the first shaft changes from the first rate of deceleration to the second rate of deceleration, is identified as the synchronous position of the synchronizer actuator fork.

Abstract: A method of controlling a hydraulic control system for a dual clutch transmission includes controlling a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A method of controlling a hydraulic control system for a dual clutch transmission includes controlling a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A method of identifying a synchronous position of a synchronizer actuator fork includes sensing a deceleration rate of a first shaft, when a synchronizer is positioned in a neutral position, to define a first rate of deceleration. The synchronizer is moved along the first shaft from the neutral position toward a gear with a synchronizer actuator fork. A deceleration rate of the first shaft is sensed, while the synchronizer actuator fork moves the synchronizer along the first shaft, to identify a change from the first rate of deceleration to a second rate of deceleration. The location, of the synchronizer actuator fork relative to the first shaft, at which the rate of acceleration of the first shaft changes from the first rate of deceleration to the second rate of deceleration, is identified as the synchronous position of the synchronizer actuator fork.

Abstract: A method of adjusting a pressure signal to an actuator piston to control movement of a synchronizer actuator fork of a transmission includes moving the synchronizer actuator fork from a start position into a target position by applying an initial fluid pressure value. The time required to move the synchronizer actuator fork is measured to define a measured actuation time, and compared to a target actuation time. A correction factor is applied to the initial fluid pressure value to define a revised fluid pressure value when the measured actuation time is not within a pre-defined time range of the target actuation time. When the measured actuation time is greater than the pre-defined time range of the target actuation time, the initial fluid pressure value is increased. When the measured actuation time is less than the pre-defined time range of the target actuation time, the initial fluid pressure value is decreased.

Abstract: A dual clutch transmission (DCT) control module includes a position control module that actuates a shift fork of the DCT during a first shift state based on a measured shift fork position and a target shift fork position. A force control module adjusts a control force associated with the shift fork during a second shift state based on synchronizer slip.

Abstract: A method of controlling a dual clutch transmission includes repeatedly moving a synchronizer into interlocking engagement with a first gear with an actuator fork, and repeatedly sensing a position of the actuator fork for each occurrence that the actuator fork moves the synchronizer into the interlocking engagement with the first gear. The sensed positions of the actuator fork are averaged to define a first engaged position of the actuator fork for engaging the first gear. A second engaged position at which the actuator fork couples the synchronizer to a second gear may be determined in the same manner. A neutral position may be determined by identifying the axial locations of peak acceleration of the actuator fork while moving between the first engaged position and the second engaged position. The identified axial locations are averaged to define the neutral position of the actuator fork.

Abstract: A hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.