Abstract: A method and system for controlling a ratio of a continuously variable transmission coupling a prime mover to a driven member in a vehicle. The method includes determining a current ratio of the continuously variable transmission, determining a projected ratio from a first ratio path of a predetermined ratio map, calculating a gradient between the current ratio and the projected ratio, determining whether the calculated gradient satisfies a gradient constraint, setting a control ratio to the projected ratio if the calculated gradient satisfies the gradient constraint, setting a control ratio to a modified ratio if the calculated gradient does not satisfy the gradient constraint, the modified ratio being based upon a ratio that satisfies the gradient constraint, and controlling the ratio of the continuously variable transmission to the control ratio.

Abstract: A method and system for controlling a ratio of a continuously variable transmission coupling a prime mover to a driven member in a vehicle. The method includes determining a current ratio of the continuously variable transmission, determining a projected ratio from a first ratio path of a predetermined ratio map, calculating a gradient between the current ratio and the projected ratio, determining whether the calculated gradient satisfies a gradient constraint, setting a control ratio to the projected ratio if the calculated gradient satisfies the gradient constraint, setting a control ratio to a modified ratio if the calculated gradient does not satisfy the gradient constraint, the modified ratio being based upon a ratio that satisfies the gradient constraint, and controlling the ratio of the continuously variable transmission to the control 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 of controlling a variator that requires clamping pressure between a first component and a second component to transfer torque therebetween, such as a continuously variable transmission, includes calculating a theoretical clamping pressure, and multiplying the theoretical clamping pressure by a multiplier to define a commanded clamping pressure. The multiplier includes a value that is variable between a minimum multiplier value and a maximum multiplier value. The value of the multiplier is based on current operating conditions of the variator. The commanded clamping pressure is applied to the first component and the second component to generate friction and transfer torque between the first component and the second component.

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 variable flow orifice for a hydraulic control system in a transmission includes a shape memory alloy that selectively increases and decreases the size of an orifice. The deformation of the shape memory alloy, and therefore the size of the orifice, is a function of the temperature of the transmission. During cold conditions the orifice size is increased and during normal operating conditions the size of the orifice is decreased.

Abstract: A vehicle includes an internal combustion engine, brake actuators configured to slow the vehicle in response to braking commands, and a transmission. The transmission includes a plurality of gear sets each having a plurality of nodes, an input member that is continuously connected to the engine and to a node of one of the gear sets, a reverse clutch, a binary clutch assembly, and a controller. The binary clutch assembly is connected at least to the same gear set as the input member, and is applied with the reverse clutch when entering a reverse gear state. The controller executes a method to transmit the braking commands to the brake actuators in response to a requested garage shift into a reverse gear state when the vehicle is rolling above a calibrated speed threshold, and thereby slows the vehicle until a calibrated target slip is achieved across the binary clutch assembly.

Abstract: A transmission for a motor vehicle with an engine includes a transmission housing and a dual clutch assembly with a clutch housing connectable to an engine output member. The clutch housing is rotationally supported within the transmission housing. The selective engagement of the dual clutch assembly interconnects the dual clutch housing with at least one of a first input member and a second input member. The transmission also includes a plurality of gear sets associated with various forward and reverse gear ratios, a controller implemented with an algorithm that provides a lock-up profile for the dual clutch assembly, and a plurality of synchronizer assemblies that couple at least one of the gear sets with at least one of a first countershaft and a second countershaft. The selective engagement of at least one of the synchronizer assemblies establishes at least one of the forward speed ratios.

Abstract: A method of controlling a variator that requires clamping pressure between a first component and a second component to transfer torque therebetween, such as a continuously variable transmission, includes calculating a theoretical clamping pressure, and multiplying the theoretical clamping pressure by a multiplier to define a commanded clamping pressure. The multiplier includes a value that is variable between a minimum multiplier value and a maximum multiplier value. The value of the multiplier is based on current operating conditions of the variator. The commanded clamping pressure is applied to the first component and the second component to generate friction and transfer torque between the first component and the second component.

Abstract: A vehicle includes an engine, drive wheels, a continuously variable transmission (CVT), and a controller. The CVT includes an input member connected to the engine, an output member delivering output torque to the wheels, and a variator assembly connecting the input and output members. The controller determines, via a method, an input and output speed of the variator assembly, converts the output speed to an equivalent input speed using a calibrated variator speed ratio, and calculates a gross slip of the variator assembly using the input and equivalent input speeds. A gross slip flag is set only when the gross slip exceeds a calibrated slip value for a predetermined duration. A CVT assembly includes the controller, input and output members, and variator assembly. The variator assembly may include drive and driven pulleys, a drive mechanism connecting the pulleys, and an actuator applying a clamping force to one of the pulleys.

Abstract: A vehicle includes an engine, drive wheels, a continuously variable transmission (CVT), and a controller. The CVT includes an input member connected to the engine, an output member delivering output torque to the wheels, and a variator assembly connecting the input and output members. The controller determines, via a method, an input and output speed of the variator assembly, converts the output speed to an equivalent input speed using a calibrated variator speed ratio, and calculates a gross slip of the variator assembly using the input and equivalent input speeds. A gross slip flag is set only when the gross slip exceeds a calibrated slip value for a predetermined duration. A CVT assembly includes the controller, input and output members, and variator assembly. The variator assembly may include drive and driven pulleys, a drive mechanism connecting the pulleys, and an actuator applying a clamping force to one of the pulleys.

Abstract: A method of managing clutch thermal loads in a multi-speed dual-clutch transmission (DCT) that is paired with an internal combustion engine in a vehicle is provided. The method includes assessing operation of the DCT and ascertaining a mode of operation of a clutch in the DCT. The method also includes predicting, in response to the ascertained mode of operation of the clutch, an amount of time remaining until the clutch reaches a threshold temperature. The method additionally includes ascertaining whether the predicted amount of time remaining until the clutch reaches the threshold temperature is within a predetermined range of time. Furthermore, the method includes activating an indicator configured to signal that the predicted amount of time remaining is within the predetermined range of time. A vehicle having a DCT, an internal combustion engine, and a controller configured to predict thermal loading on a clutch in the DCT is also disclosed.

Abstract: A vehicle includes an engine and transmission having gear sets, an input member that is continuously connected to the engine and a gear set, a binary clutch assembly, a speed sensor, and a controller. The binary clutch assembly includes a freewheeling element holding torque in one rotational direction, and also a selectable one-way clutch (SOWC) portion holding torque in two rotational directions when applied. The controller executes a method to transmit a first binary clutch command to the binary clutch assembly and thus apply the SOWC portion at vehicle launch, and calculates, via the processor, an acceleration value of the vehicle using the measured speed. The controller also selects a shift apply point of the binary clutch assembly as a function of the calculated acceleration value, and transmits a second binary clutch command to the binary clutch assembly to release the SOWC portion at the selected shift apply point.

Abstract: A hydraulic control system for a transmission of a motor vehicle includes a source of pressurized hydraulic fluid that communicates with an analog electronic transmission range selection (ETRS) subsystem or a manual valve. The ETRS subsystem includes an ETRS valve, a park servo, a park mechanism, a mode valve, and a plurality of solenoids. The ETRS and manual valve communicate with a clutch actuator subsystem that engages a one-way clutch and six clutches/brakes.

Abstract: A control system for an automatic transmission includes a double transition shift detection module and first and second clutch control modules. The double transition shift detection module detects whether a double transition shift operation is requested. The first clutch control module controls two of four transitioning clutches of the transmission during an inertia phase of the double transition shift operation. The second clutch control module controls each of the four transitioning clutches of the transmission during a torque phase of the double transition shift operation.

Abstract: A control system for a dry dual clutch transmission (DCT) includes first, second, and third modules. The first module detects whether a hydraulic pressure sensor of a hydraulic fluid delivery system in the dry DCT has failed. The second module estimates a pressure of hydraulic fluid within an accumulator of the hydraulic fluid delivery system based on one of (i) torque generated by and temperature of a hydraulic fluid pump and (ii) a drain down period of the accumulator and a period since the hydraulic fluid pump was on. The third module controls start/stop of the hydraulic fluid pump based on the estimated hydraulic fluid pressure when the hydraulic pressure sensor has failed.

Abstract: A vehicle includes an internal combustion engine, brake actuators configured to slow the vehicle in response to braking commands, and a transmission. The transmission includes a plurality of gear sets each having a plurality of nodes, an input member that is continuously connected to the engine and to a node of one of the gear sets, a reverse clutch, a binary clutch assembly, and a controller. The binary clutch assembly is connected at least to the same gear set as the input member, and is applied with the reverse clutch when entering a reverse gear state. The controller executes a method to transmit the braking commands to the brake actuators in response to a requested garage shift into a reverse gear state when the vehicle is rolling above a calibrated speed threshold, and thereby slows the vehicle until a calibrated target slip is achieved across the binary clutch assembly.

Abstract: A vehicle includes an engine and transmission having gear sets, an input member that is continuously connected to the engine and a gear set, a binary clutch assembly, a speed sensor, and a controller. The binary clutch assembly includes a freewheeling element holding torque in one rotational direction, and also a selectable one-way clutch (SOWC) portion holding torque in two rotational directions when applied. The controller executes a method to transmit a first binary clutch command to the binary clutch assembly and thus apply the SOWC portion at vehicle launch, and calculates, via the processor, an acceleration value of the vehicle using the measured speed. The controller also selects a shift apply point of the binary clutch assembly as a function of the calculated acceleration value, and transmits a second binary clutch command to the binary clutch assembly to release the SOWC portion at the selected shift apply point.

Abstract: A hydraulic control system for a transmission of a motor vehicle includes a source of pressurized hydraulic fluid that communicates with an analog electronic transmission range selection (ETRS) subsystem or a manual valve. The ETRS subsystem includes an ETRS valve, a park servo, a park mechanism, a mode valve, and a plurality of solenoids. The ETRS and manual valve communicate with a clutch actuator subsystem that engages a one-way clutch and six clutches/brakes.

Abstract: A method of managing clutch thermal loads in a multi-speed dual-clutch transmission (DCT) that is paired with an internal combustion engine in a vehicle is provided. The method includes assessing operation of the DCT and ascertaining a mode of operation of a clutch in the DCT. The method also includes predicting, in response to the ascertained mode of operation of the clutch, an amount of time remaining until the clutch reaches a threshold temperature. The method additionally includes ascertaining whether the predicted amount of time remaining until the clutch reaches the threshold temperature is within a predetermined range of time. Furthermore, the method includes activating an indicator configured to signal that the predicted amount of time remaining is within the predetermined range of time. A vehicle having a DCT, an internal combustion engine, and a controller configured to predict thermal loading on a clutch in the DCT is also disclosed.