Abstract: A target module determines a target ratio between a speed of an input shaft and a speed of an output shaft of a continuously variable transmission (CVT) based on an accelerator pedal position. A maximum rate of change (ROC) module determines a maximum ROC of the target ratio. A switching valve control module, based on a comparison of the maximum ROC and a ROC of the target ratio, selectively actuates a switching valve of the CVT one of (i) from a closed position to an open position and (ii) from the open position to the closed position. The switching valve prevents transmission fluid flow through a flow path between a transmission fluid pump and a pressure regulator valve of the CVT when the switching valve is in the closed position. The switching valve allows transmission fluid flow through the flow path when the switching valve is in the open position.

Abstract: A switching valve control module selectively actuates a switching valve of a continuously variable transmission (CVT) either: (i) from a closed position to an open position; or (ii) from the open position to the closed position. The switching valve prevents and allows transmission fluid flow through a flow path between a transmission fluid pump and a pressure regulator valve of the CVT when the switching valve is in the closed position and the open position, respectively. An adjustment determination module determines a pressure adjustment when the switching valve actuates. A target pressure module determines a target pressure output from the pressure regulator valve. An adjusting module determines an adjusted target pressure based on the pressure adjustment and the target pressure. A regulator valve control module controls opening of the pressure regulator valve based on the adjusted target pressure.

Abstract: A torque converter clutch (TCC) release fluid lubrication system for a motor vehicle transmission includes a first fluid line, a second fluid line and a third fluid line. The first fluid line supplies TCC apply fluid to the TCC. The second fluid line receives TCC release fluid from the TCC. And the third fluid line supplies a first lubrication fluid to the transmission. The TCC release fluid and the first lubrication fluid combine into a second lubrication fluid that is fed into the transmission.

Abstract: A hydraulic control system with clutch and torque converter control for a CVT includes a pressure regulator subsystem, a cooler subsystem, a manual valve assembly, and a torque converter control valve assembly connected to the torque converter clutch (TCC) and the cooler subsystem. A boost valve assembly is connected to the pressure regulator subsystem, the manual valve assembly, and the torque converter clutch control valve assembly. A clutch control solenoid is configured to move the boost valve to the boost position and the control valve to the release position and to control a pressure of the hydraulic fluid provided to the manual valve assembly. A TCC control solenoid is configured to move the boost valve to the boost position and to control a pressure of the hydraulic fluid provided to the torque converter control valve assembly.

Abstract: A hydraulic control system with clutch and torque converter control for a CVT includes a pressure regulator subsystem, a cooler subsystem, a manual valve assembly, and a torque converter control valve assembly connected to the torque converter clutch (TCC) and the cooler subsystem. A boost valve assembly is connected to the pressure regulator subsystem, the manual valve assembly, and the torque converter clutch control valve assembly. A clutch control solenoid is configured to move the boost valve to the boost position and the control valve to the release position and to control a pressure of the hydraulic fluid provided to the manual valve assembly. A TCC control solenoid is configured to move the boost valve to the boost position and to control a pressure of the hydraulic fluid provided to the torque converter control valve assembly.

Abstract: A vehicle includes an engine, a transmission with a shift valve, an alternator, an auxiliary battery, a voltage sensor operable to measure an auxiliary voltage, and an electronic transmission range selection (ETRS) system. The ETRS system includes a controller, and also an electronic range selector device that transmits an electronic range request signal to the controller to request the shift of the transmission to a requested operating range. The controller executes a method to predict a loss of auxiliary power aboard the vehicle, and to control an action of the vehicle in response to the predicted loss of auxiliary power. The electronic range request signal is received from the range selector device and auxiliary voltage. The controller calculates a slope of a decrease in the measured auxiliary voltage. A control action is executed with the alternator is in the charging state and the calculated slope exceeds a calibrated slope threshold.

Abstract: A variable force solenoid valve and a switching valve provide minimal line pressure disturbance in the output of an engine driven balanced hydraulic pump when switching between full flow and half flow in an automatic transmission.

Abstract: A system includes a fluid pump, a hydraulic accumulator, and a controller. The controller calculates a reserve volume of the accumulator as a function of a component volume, leakage in the system, and a displacement of the pump, and executes a control action using the calculated reserve volume. The system may be a vehicle having input clutches and a dual clutch transmission (DCT) having gear forks. In such an embodiment, the accumulator and pump supply fluid pressure to the input clutches and gear forks in response to control signals from the controller. The controller executes a method that includes calculating the reserve volume of the accumulator as a function of a component volume, a volume of leakage in the system, and a displacement of the fluid pump. The method also includes executing a shift of the DCT using the calculated reserve volume.

Abstract: A vehicle or other system includes hydraulic fluid, an actuatable device such as a clutch that includes a linear actuator, e.g., a clutch piston. The linear actuator is moveable via a pressure from the fluid to actuate the actuatable device. A position sensor measures and outputs a position of the linear actuator as a position signal. A controller is programmed to generate increasing and decreasing position-to-pressure (PTP) curves via measurement of the position, at a predetermined time, in response to a series of respectively increasing and decreasing pressure step commands. The controller adjusts the PTP curves using a calibrated set of offsets, locates a PTP point in a hysteresis range between the adjusted PTP curves, and controls the device using the PTP point. The offsets may include a temperature of the fluid, velocity of the linear actuator, and/or an engine speed.

Abstract: A vehicle includes an engine, a transmission with a shift valve, an alternator, an auxiliary battery, a voltage sensor operable to measure an auxiliary voltage, and an electronic transmission range selection (ETRS) system. The ETRS system includes a controller, and also an electronic range selector device that transmits an electronic range request signal to the controller to request the shift of the transmission to a requested operating range. The controller executes a method to predict a loss of auxiliary power aboard the vehicle, and to control an action of the vehicle in response to the predicted loss of auxiliary power. The electronic range request signal is received from the range selector device and auxiliary voltage. The controller calculates a slope of a decrease in the measured auxiliary voltage. A control action is executed with the alternator is in the charging state and the calculated slope exceeds a calibrated slope threshold.

Abstract: A vehicle includes an engine, first clutch, transmission, and controller. The transmission includes a gearbox, position sensors, and a fluid circuit. The gearbox contains a second clutch. The fluid circuit includes a pump and a flow control solenoid valve. The controller opens the valve via flow control signals to allow fluid to pass into or from the particular clutch it feeds. The controller executes steps of a method to determine an actual flow rate through the valve as the clutch moves, and also calculates a compensation scale factor as a ratio of the commanded and actual flow rates. The controller modifies the flow control signals in a subsequent clutch actuation using the compensation scale factor, such as by multiplying a commanded flow rate corresponding to the flow control signals by the compensation scale factor. A system includes rotatable members connected by a clutch, the controller, valve, and position sensor.

Abstract: A vehicle includes an engine, a dry dual-clutch transmission (dDCT) having a pair of input clutches and a gearbox containing oddly- and evenly-numbered gear sets, and a transmission control module (TCM). Application of one of input clutches connects the engine to a corresponding one of the oddly- or evenly-numbered gear sets. The TCM includes feed-forward PID-based control logic, and a torque-to-position (TTP) table for each input clutch. The TCM commands a position of a designated input clutch during a power-on upshift using the feed-forward, PID-based control logic, and selectively adapts the TTP table as a function of an inertia and acceleration value of the engine. The TCM may apply an asymmetrical handoff profile to commanded oncoming and offgoing clutch torques during the torque phase of the upshift. The TCM may also adjust the TTP table as a function of the frequency of use of the input clutches.

Abstract: A system includes a fluid pump, a hydraulic accumulator, and a controller. The controller calculates a reserve volume of the accumulator as a function of a component volume, leakage in the system, and a displacement of the pump, and executes a control action using the calculated reserve volume. The system may be a vehicle having input clutches and a dual clutch transmission (DCT) having gear forks. In such an embodiment, the accumulator and pump supply fluid pressure to the input clutches and gear forks in response to control signals from the controller. The controller executes a method that includes calculating the reserve volume of the accumulator as a function of a component volume, a volume of leakage in the system, and a displacement of the fluid pump. The method also includes executing a shift of the DCT using the calculated reserve volume.

Abstract: A vehicle or other system includes hydraulic fluid, an actuatable device such as a clutch that includes a linear actuator, e.g., a clutch piston. The linear actuator is moveable via a pressure from the fluid to actuate the actuatable device. A position sensor measures and outputs a position of the linear actuator as a position signal. A controller is programmed to generate increasing and decreasing position-to-pressure (PTP) curves via measurement of the position, at a predetermined time, in response to a series of respectively increasing and decreasing pressure step commands. The controller adjusts the PTP curves using a calibrated set of offsets, locates a PTP point in a hysteresis range between the adjusted PTP curves, and controls the device using the PTP point. The offsets may include a temperature of the fluid, velocity of the linear actuator, and/or an engine speed.

Abstract: A vehicle includes an engine, first clutch, transmission, and controller. The transmission includes a gearbox, position sensors, and a fluid circuit. The gearbox contains a second clutch. The fluid circuit includes a pump and a flow control solenoid valve. The controller opens the valve via flow control signals to allow fluid to pass into or from the particular clutch it feeds. The controller executes steps of a method to determine an actual flow rate through the valve as the clutch moves, and also calculates a compensation scale factor as a ratio of the commanded and actual flow rates. The controller modifies the flow control signals in a subsequent clutch actuation using the compensation scale factor, such as by multiplying a commanded flow rate corresponding to the flow control signals by the compensation scale factor. A system includes rotatable members connected by a clutch, the controller, valve, and position sensor.

Abstract: A vehicle includes an engine, a transmission, and a controller which executes a method. The transmission includes a clutch having an actuator which applies the clutch using position-based control logic. The transmission also includes a fluid pump and a variable-force or other solenoid valve positioned downstream of the pump and upstream of the clutch. The valve outputs a flow rate (Q) for a corresponding solenoid control current (I). The controller adapts a calibrated Q vs. I characteristic table of the valve for different transmission temperatures by applying closed-loop position control signals to the actuator at the different transmission temperatures and recording a null point(s) describing the corresponding solenoid control current (I) at a zero flow rate condition. The controller calculates an offset value for solenoid control current (I) using the recorded null point(s), applies the offset value to the characteristic table, and controls the clutch using the adapted characteristic table.

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 system for providing pressurized hydraulic fluid includes an engine driven main pump and an electrical motor driven auxiliary pump. The auxiliary pump provides hydraulic fluid at line pressure to shift control subsystems during a vehicle launch while the main pump provides hydraulic fluid to cooler or lubrication subsystems during the vehicle launch. A pressure regulation valve regulates the pressure of the hydraulic fluid from the main pump. Once the main pump reaches a critical speed, the main pump provides hydraulic fluid at line pressure to the hydraulic control system and the auxiliary pump is turned off.

Abstract: A vehicle includes an engine, a transmission, and a controller which executes a method. The transmission includes a clutch having an actuator which applies the clutch using position-based control logic. The transmission also includes a fluid pump and a variable-force or other solenoid valve positioned downstream of the pump and upstream of the clutch. The valve outputs a flow rate (Q) for a corresponding solenoid control current (I). The controller adapts a calibrated Q vs. I characteristic table of the valve for different transmission temperatures by applying closed-loop position control signals to the actuator at the different transmission temperatures and recording a null point(s) describing the corresponding solenoid control current (I) at a zero flow rate condition. The controller calculates an offset value for solenoid control current (I) using the recorded null point(s), applies the offset value to the characteristic table, and controls the clutch using the adapted characteristic table.

Abstract: A method of controlling thermal loading in a multi-speed dual-clutch transmission (DCT) that is paired with an internal combustion engine in a vehicle is provided. The method includes detecting operation of the vehicle and ascertaining a degree of thermal loading on the DCT. The method also includes selecting a remedial action corresponding to the ascertained degree of thermal loading. Additionally, the method includes activating the selected remedial action such that the thermal loading on the DCT is reduced. A vehicle having a DCT, an internal combustion engine, and a controller configured to control thermal loading in the DCT is also disclosed.