Abstract: A transmission control system for a vehicle includes a transmission control module (TCM), a solenoid valve, a pressure regulator valve, and a transmission element. The TCM includes a control algorithm providing output signals to valve drive electronics, where the valve drive electronics supply current to the solenoid valve. The solenoid valve controls an output pressure located in a passage between the pressure regulator valve and the transmission element. During an engine start-up condition of the vehicle, the control algorithm of the TCM includes control logic for activating a solenoid adjustment algorithm. The solenoid adjustment algorithm decreases the sensitivity of the valve drive electronics when supplying current to the solenoid valve. The solenoid adjustment algorithm is activated for a predetermined amount of time after engine start-up, and is then terminated.

Abstract: A vehicle includes a brake pedal, engine, transmission, and controller. The transmission includes an input member and an input clutch responsive to position control signals. The controller has multiple control modules, each outputting a corresponding torque command. One module is a creep control module which outputs a calibrated creep torque. Intervention logic independently monitors the torque commands during a creep maneuver, with control actions executed when predetermined conditions are present. The torque command from the creep controller determines the position control signals of the input clutch during the creep maneuver, and creep torque is set to zero whenever the brake pedal is sufficiently applied. A transmission assembly includes the input member, input clutch, and controller.

Abstract: A system according to the principles of the present disclosure includes an axle torque determination module, an engine torque determination module, a torque security module, and an engine torque control module. The axle torque determination module determines an axle torque request based on a driver input and a vehicle speed. The engine torque determination module determines an engine torque request based on the axle torque request and at least one of a first turbine speed and whether a clutch of a torque converter is applied. The torque security module determines a secured torque request based on at least one of the driver input, the vehicle speed, and an engine speed. The engine torque control module controls an amount of torque produced by an engine based on one of the engine torque request and the secured torque request.

Abstract: A transmission assembly for a vehicle includes a transmission and a controller. The transmission includes an input member, at least one clutch and gear set, and an output member. The input member receives an input torque from an engine. The output member receives an output torque from the clutch and gear set(s). The clutch and gear set(s) connect to the input member and establish a plurality of operating states including a neutral idle (NI) state. A designated NI clutch is selectively actuated to enter the NI state when the transmission is in a drive state and the vehicle is stationary. The controller calculates a reference slip error as a function of engine and turbine speed, and detects when the designated NI clutch is exhausting fluid while operating in the NI state using a function of the reference slip error. A control action executes when the exhausting NI clutch is detected.

Abstract: A vehicle includes an engine having a crankshaft which rotates at an engine speed, a transmission having a rotatable input member, a transmission control module (TC), and an engine control module (ECM) in communication with the TCM. The TCM is programmed to execute a transmission-to-engine speed monitoring and control method which includes transmitting an engine speed request to the ECM which requests a positive increase in the engine speed, and terminating the request when the request is active for more than a first calibrated timeout duration. The TCM also terminates the request when the request is active for more than a second calibrated duration that is less than the first calibrated duration, the transmission is not in neutral, and both a shift of the transmission and an acceleration of the input member are not active.

Abstract: A vehicle includes a brake pedal, engine, transmission, and controller. The transmission includes an input member and an input clutch responsive to position control signals. The controller has multiple control modules, each outputting a corresponding torque command. One module is a creep control module which outputs a calibrated creep torque. Intervention logic independently monitors the torque commands during a creep maneuver, with control actions executed when predetermined conditions are present. The torque command from the creep controller determines the position control signals of the input clutch during the creep maneuver, and creep torque is set to zero whenever the brake pedal is sufficiently applied. A transmission assembly includes the input member, input clutch, and controller.

Abstract: A vehicle includes an engine, transmission, engine control module (ECM), and transmission control module (TCM). The transmission includes an input member and an input clutch which selectively connects a crankshaft of the engine to the input member. The TCM identifies a target clutch torque of the input clutch during a creep maneuver of the vehicle, and communicates the identified target clutch torque to the ECM. The ECM maintains engine idle speed at a threshold level through the creep maneuver and a requested launch using the target clutch torque as a feed-forward term. A method includes identifying a target clutch torque of the input clutch during a creep maneuver, and communicating the identified target clutch torque to the ECM. The idle speed is maintained at a threshold level by the ECM through the creep maneuver and a detected launch using the target clutch torque as a feed-forward idle speed control term.

Abstract: A vehicle includes an engine, a torque converter, a transmission, and a controller. The transmission has an input member connected to a turbine of the torque converter. The transmission includes a neutral idle (NI) state and a designated NI clutch actuated to enter the NI state. The controller calculates a reference slip error as a function of engine speed and turbine speed, detects when the designated NI clutch is exhausting while operating in the NI state as a function of the reference slip error, and executes a control action when the exhausting NI clutch is detected. A method includes measuring engine and turbine speed, calculating the reference slip error value as a function of the engine and turbine speeds, detecting when the designated NI clutch is exhausting while operating in the NI state using the reference slip error, and executing a control action when the exhausting NI clutch is detected.

Abstract: A method of controlling a vehicle includes detecting vibration in a drivetrain of the vehicle with a fore/aft accelerometer during a launch event. An operating regime of the vehicle is identified concurrently with the detected vibration when the detected vibration is outside a predefined allowable range. A control strategy of the drivetrain is adjusted to define a revised control strategy to avoid the identified operating regime. The revised control strategy is applied to control the drivetrain to mitigate vibration in the drivetrain.

Abstract: An engine system of a vehicle includes an engine torque module. The engine torque module determines an engine output torque profile including predicted torque outputs based on an accelerator signal and an engine state variable. A load control module determines a dynamic transmission load profile based on the engine output torque profile and an engine speed profile. The dynamic transmission load profile includes transmission loads as a function of engine speed during an auto-start of an engine. A compensation module generates a torque compensation signal based on the dynamic transmission load profile. An actuator module compensates for a change in a transmission load based on the torque compensation signal and during a transition of the engine from a cranking state to an idle state.

Abstract: A vehicle having engine stop-start functionality includes a transmission, engine, and controller. The transmission includes a clutch, and the engine includes a crankshaft. The controller is in communication with the engine and the transmission, and is configured for detecting a commanded shut down of the engine, and then engaging the clutch to control a rate of deceleration of the crankshaft and stop the crankshaft within a calibrated range of a target stop position at the end of engine shut down. A method for controlling engine stop position includes detecting a commanded shut down of the engine, and engaging the clutch after detecting the commanded shut down to thereby control the rate of deceleration of the crankshaft and stop the crankshaft within a calibrated range of a target stop position at the end of shut down of the engine. The transmission may be automatic or it may be a dual-clutch transmission.

Abstract: An engine control system for an auto-stop/start vehicle, comprising: an actuator control module, a correction determination module, and a spark adjustment module. The actuator control module determines a target spark timing for a first time that is between a second time when engine cranking begins and a third time when a measured engine speed becomes greater than a predetermined engine speed after the second time. The correction determination module determines a spark timing correction for the first time based on a target engine speed and a measured engine speed. The spark adjustment module sets a spark timing for the first time based on the target spark timing and the spark timing correction.

Abstract: A vehicle includes an engine, an automatic transmission, and a controller. The transmission includes a neutral idle (NI) state and a designated NI clutch which is selectively actuated to exit the NI state. The controller executes instructions from tangible memory to shift out of the NI state and into a drive state. The controller includes a slip model which generates a desired clutch slip profile as a differentiable time function, and a desired slip derivative of the desired slip profile. The desired profiles are used to calculate a clutch pressure command for controlling the designated NI clutch. The time function may be at least a third order/cubic equation. A method includes executing the slip model to generate the desired clutch slip profile, calculating a desired slip derivative of the desired slip profile, and using the desired slip profile derivative to calculate a clutch pressure command for the designated NI clutch.

Abstract: A transmission includes a plurality of clutches that are selectively engageable alone or in combination with each other to establish a plurality of forward drive modes, wherein one of the clutches is configured as a neutral idle (NI) clutch that is selectively actuated to shift the transmission into an NI state, and a controller. The controller is adapted to shift the transmission from a forward drive mode into the NI state during a coast-down maneuver prior to the transmission reaching a zero output speed. A method of shifting the transmission into the NI state includes determining the presence of a predetermined one of the forward drive modes using the controller, and using the controller to actuate a designated one of the clutches as an NI clutch to enter the NI state during the forward drive mode, during a coast-down maneuver, and prior to the transmission reaching a zero output speed.

Abstract: A vehicle includes an engine, a torque converter, a transmission, and a controller. The transmission has an input member connected to a turbine of the torque converter. The transmission includes a neutral idle (NI) state and a designated NI clutch actuated to enter the NI state. The controller calculates a reference slip error as a function of engine speed and turbine speed, detects when the designated NI clutch is exhausting while operating in the NI state as a function of the reference slip error, and executes a control action when the exhausting NI clutch is detected. A method includes measuring engine and turbine speed, calculating the reference slip error value as a function of the engine and turbine speeds, detecting when the designated NI clutch is exhausting while operating in the NI state using the reference slip error, and executing a control action when the exhausting NI clutch is detected.

Abstract: A vehicle includes an engine, torque converter, transmission, accumulator, sensor, and controller. The engine is automatically restarted in response to a start signal during an engine auto-start event. The transmission has a calibrated line pressure and a plurality (n) of clutches. The (n) clutches are engaged to execute the engine auto-start event. The accumulator delivers fluid under pressure to the transmission in response to the start signal. The controller controls (n?1) of the plurality (n) of clutches to the calibrated line pressure in response to detecting the start signal. The controller also modifies clutch fill parameters which control a fill sequence of the remaining clutch, i.e., the designated control clutch, as a function of a deviation of the measured turbine speed from a theoretical no-slip turbine speed. A system includes the transmission, sensor, accumulator, and controller. A method for controlling the designated clutch is also disclosed.

Abstract: A vehicle includes an engine, torque converter, transmission, accumulator, sensor, and controller. The engine is automatically restarted in response to a start signal during an engine auto-start event. The transmission has a calibrated line pressure and a plurality (n) of clutches. The (n) clutches are engaged to execute the engine auto-start event. The accumulator delivers fluid under pressure to the transmission in response to the start signal. The controller controls (n?1) of the plurality (n) of clutches to the calibrated line pressure in response to detecting the start signal. The controller also modifies clutch fill parameters which control a fill sequence of the remaining clutch, i.e., the designated control clutch, as a function of a deviation of the measured turbine speed from a theoretical no-slip turbine speed. A system includes the transmission, sensor, accumulator, and controller. A method for controlling the designated clutch is also disclosed.

Abstract: A control system for a vehicle having a dry dual clutch transmission (DCT) includes a launch condition detection module, a vehicle stop module, and a vehicle launch module. The launch condition detection module detects a launch condition based on whether (i) the vehicle is on an uphill grade and (ii) a driver of the vehicle has requested power via an accelerator. The vehicle stop module stops the vehicle when the launch condition is detected by (i) commanding an on-coming clutch of the dry DCT to a predetermined position and (ii) applying brakes of the vehicle. The vehicle launch module launches the vehicle after the vehicle is stopped by (i) fully engaging the on-coming clutch of the dry DCT and (ii) opening a throttle to a desired position corresponding to the power request.

Abstract: A vehicle having engine stop-start functionality includes a transmission, engine, and controller. The transmission includes a clutch, and the engine includes a crankshaft. The controller is in communication with the engine and the transmission, and is configured for detecting a commanded shut down of the engine, and then engaging the clutch to control a rate of deceleration of the crankshaft and stop the crankshaft within a calibrated range of a target stop position at the end of engine shut down. A method for controlling engine stop position includes detecting a commanded shut down of the engine, and engaging the clutch after detecting the commanded shut down to thereby control the rate of deceleration of the crankshaft and stop the crankshaft within a calibrated range of a target stop position at the end of shut down of the engine. The transmission may be automatic or it may be a dual-clutch transmission.

Abstract: A vehicle includes an engine that shuts down and restarts at idle, a dual-clutch transmission (DCT) having a controller and two input clutches for connecting the engine to respective evenly and oddly numbered gears of the DCT. The controller has a shift algorithm for shifting the DCT to achieve a predetermined engine load state during an engine autostart/autostop cycle, with the load state being unloaded or partially loaded. A DCT for the vehicle includes the input clutches and controller. A method includes shifting the DCT to the predetermined engine load state while the engine is off and an engine restart is commanded, and restarting the engine in the engine load state. The method may also include maintaining the clutches at a first point relative to a kiss point of the input clutches when the load state is unloaded, and at a second point when the load state is partially loaded.