Abstract: A system includes a torque converter having a turbine, a transmission having friction clutches and an input member connected to the turbine, and a controller. The controller is programmed to control a change-of-mind shift maneuver of the transmission. By executing a method, the controller detects the change-of-mind shift maneuver, predicts an acceleration profile of the turbine for a next-requested shift of the detected shift maneuver as a function of a calibrated desired shift time and an output speed of the transmission, calculates a shift control value for a next-requested shift of the shift maneuver using the predicted acceleration profile, and executes the next-requested shift via the clutches using the calculated shift control value. The shift maneuver may be a skip-at-sync quick shift-to-quick shift or power downshift-to-power downshift. The shift value may be a clutch pressure for an offgoing holding clutch or a torque management level from an engine.

Abstract: A method for monitoring a fixed-gear transmission includes deriving a node speed relationship for each of the planetary gear sets based upon a center distance and a gear ratio and determining equivalent speed parameters for nodes of the planetary gear sets based upon a transmission input speed state, an intermediate node speed state and a transmission output speed state. A clutch slip speed relationship is determined for each of the clutches based upon the node speed relationships for the planetary gear sets and the equivalent speed parameters for nodes of the planetary gear sets. Rotational speed sensors monitor the input transmission speed, the intermediate node speed and the transmission output speed. A clutch slip speed for each of the clutches is determined based upon the respective clutch slip speed relationship and the monitored input transmission speed, the monitored intermediate node speed and the monitored transmission output speed.

Abstract: A fixed-gear transmission including a plurality of planetary gear sets and a plurality of clutches is described. A method for controlling the fixed-gear transmission includes commanding a first iteration of a skip-at-sync transmission shift and monitoring clutch slip of an oncoming holding clutch associated with the skip-at-sync transmission shift during execution of the shift, which includes monitoring synchronization of the on-coming holding clutch and a maximum clutch slip overshoot value. A progressive clutch pressure ramp rate for the oncoming holding clutch is adaptively controlled in response to the clutch synchronization of the on-coming hold clutch during execution of a subsequent iteration of the skip-at-sync transmission shift.

Abstract: A fixed-gear transmission including a plurality of planetary gear sets and a plurality of clutches is described. A method for controlling the fixed-gear transmission includes commanding a first iteration of a skip-at-sync transmission shift and monitoring clutch slip of an oncoming holding clutch associated with the skip-at-sync transmission shift during execution of the shift, which includes monitoring synchronization of the on-coming holding clutch and a maximum clutch slip overshoot value. A progressive clutch pressure ramp rate for the oncoming holding clutch is adaptively controlled in response to the clutch synchronization of the on-coming hold clutch during execution of a subsequent iteration of the skip-at-sync transmission shift.

Abstract: A system includes a torque converter having a turbine, a transmission having friction clutches and an input member connected to the turbine, and a controller. The controller is programmed to control a change-of-mind shift maneuver of the transmission. By executing a method, the controller detects the change-of-mind shift maneuver, predicts an acceleration profile of the turbine for a next-requested shift of the detected shift maneuver as a function of a calibrated desired shift time and an output speed of the transmission, calculates a shift control value for a next-requested shift of the shift maneuver using the predicted acceleration profile, and executes the next-requested shift via the clutches using the calculated shift control value. The shift maneuver may be a skip-at-sync quick shift-to-quick shift or power downshift-to-power downshift. The shift value may be a clutch pressure for an offgoing holding clutch or a torque management level from an engine.

Abstract: A method of controlling a transmission includes determining if the transmission is currently executing a first torque controlled shift from a first gear ratio to a second gear ratio. A torque controlled shift is defined as a shift control operation in which the speed of the engine is controlled to perform a shift operation. When a second torque controlled shift is detected while the transmission is currently executing the first torque controlled shift, a dual torque controlled shift strategy is executed, which merges a first shift control strategy for executing the first torque controlled shift with a second shift control strategy for executing the second torque controlled shift. The dual torque controlled shift strategy seamlessly executes the first torque controlled shift and the second torque controlled shift without a time delay and engine torque disruption therebetween.

Abstract: A method for monitoring a fixed-gear transmission includes deriving a node speed relationship for each of the planetary gear sets based upon a center distance and a gear ratio and determining equivalent speed parameters for nodes of the planetary gear sets based upon a transmission input speed state, an intermediate node speed state and a transmission output speed state. A clutch slip speed relationship is determined for each of the clutches based upon the node speed relationships for the planetary gear sets and the equivalent speed parameters for nodes of the planetary gear sets. Rotational speed sensors monitor the input transmission speed, the intermediate node speed and the transmission output speed. A clutch slip speed for each of the clutches is determined based upon the respective clutch slip speed relationship and the monitored input transmission speed, the monitored intermediate node speed and the monitored transmission output speed.

Abstract: A method of controlling clutches in a multi-speed transmission includes beginning a current shift from a starting gear to an initial target gear, and determining whether the current shift is a downshift. The method determines jump-stage eligibility of a first clutch. Determining jump-stage eligibility includes determining whether the first clutch is a holding clutch for the current shift, and determining whether the first clutch is an off-going clutch for a legal shift from the initial starting gear to an adjusted target gear having a higher speed ratio than the initial starting gear. If the first clutch is not jump-stage eligible, the method maintains pressure of the first clutch at a current pressure. If the first clutch is jump-stage eligible, the method reduces the pressure of the first clutch from the current pressure to a staging pressure, which is greater than a slipping pressure.

Abstract: A method of controlling a transmission includes determining if the transmission is currently executing a first torque controlled shift from a first gear ratio to a second gear ratio. A torque controlled shift is defined as a shift control operation in which the speed of the engine is controlled to perform a shift operation. When a second torque controlled shift is detected while the transmission is currently executing the first torque controlled shift, a dual torque controlled shift strategy is executed, which merges a first shift control strategy for executing the first torque controlled shift with a second shift control strategy for executing the second torque controlled shift. The dual torque controlled shift strategy seamlessly executes the first torque controlled shift and the second torque controlled shift without a time delay and engine torque disruption therebetween.

Abstract: A clutch control process for a motor vehicle transmission during brake lift-out monitors a time rate of change of a brake pedal position and torque to detect a lift-out condition with rapidly changing torque. When the process detects a brake lift-out condition, the process limits the minimum scheduled clutch pressure as well as modifies the clutch pressure to torque relationship.

Abstract: A control system for a transmission coupled to an engine includes first, second, and third modules. The first module detects a closed throttle downshift of the transmission. The second module detects a request for a power-on downshift of the transmission. The third module controls a clutch of the transmission when the request for the power-on downshift is detected during the closed throttle downshift, wherein the third module one of (i) decreases a pressure applied to the clutch to a first predetermined pressure before an end of the closed throttle downshift and (ii) controls a pressure applied to the clutch to a second predetermined pressure at the end of the closed throttle downshift.

Abstract: A control system for a transmission coupled to an engine includes first, second, and third modules. The first module detects a closed throttle downshift of the transmission. The second module detects a request for a power-on downshift of the transmission. The third module controls a clutch of the transmission when the request for the power-on downshift is detected during the closed throttle downshift, wherein the third module one of (i) decreases a pressure applied to the clutch to a first predetermined pressure before an end of the closed throttle downshift and (ii) controls a pressure applied to the clutch to a second predetermined pressure at the end of the closed throttle downshift.

Abstract: A clutch control process for a motor vehicle transmission during brake lift-out monitors a time rate of change of a brake pedal position and torque to detect a lift-out condition with rapidly changing torque. When the process detects a brake lift-out condition, the process limits the minimum scheduled clutch pressure as well as modifies the clutch pressure to torque relationship.