Abstract: A vehicle powertrain includes an engine and an electric motor in parallel hybrid combination. The engine includes a plurality of cylinders and a plurality of selectively deactivatable cylinder intake and exhaust valves so that every cylinder in the engine is characterized by an inoperative condition in which corresponding intake and exhaust valves remain in a closed position irrespective of crankshaft rotation. A controller is operatively connected to the valves and configured to advantageously control the valves and render cylinders inoperative. The powertrain enables the rotor of the motor to be continuously operatively connected to the crankshaft of the engine for unitary rotation therewith. The powertrain is preferably characterized by integrated friction launch wherein an active torque-transmitting mechanism controls vehicle launch.

Abstract: A piston support housing for a transmission assembly includes a plurality of axially-extending finger portions engaging a plurality of spline portions formed in a corresponding transmission case, and a plurality of friction plates are assembled adjacent the piston support housing such that the finger portions extend circumjacent peripheral edges of the friction plates. The friction plates include a plurality of torque-transmitting spline portions disposed circumferentially intermediate the finger portions. The friction plates also include a plurality of recesses disposed with one adjacent each of the finger portions to preclude contact between the finger portions and the friction plates thereby preventing torque-transmission through the finger portions to the transmission case.

Abstract: The present invention provides a method for improving fuel economy in hybrid vehicles. More precisely, the method of the present invention includes a selectable “learn mode” in which the vehicle can learn a particular driving schedule. After a particular driving schedule is learned, the schedule can be recalled to optimize fuel economy on future trips following the same route. By recalling a learned schedule, the system knows in advance what energy level will be needed and can proactively charge the hybrid vehicle's battery to an appropriate level.

Abstract: A two-mode compound-split hydro-mechanical powertrain employs a hydro-mechanical continuously variable transmission having two hydraulic units, at least two torque-transmitting mechanisms, and a planetary gear arrangement for combining the output of an engine and the two hydraulic units into a single output mechanism.

Abstract: An electrically variable transmission includes an input member to receive power from an engine about a primary axis; an output member connected to a transfer member for transmitting power to a secondary axis; first and second motor/generators; first and second torque transfer devices; and first and second planetary gear sets each having first, second and third members. The input member is continuously connected to the first member of the first gear set, and the output member is continuously connected to the first member of the second gear set. The first motor/generator is continuously connected to the second member of the first gear set. The second motor/generator is continuously connected with the third member of the first or second gear set. The transfer member is positioned between the first and second motor/generators.

Abstract: A selectively operable one-way torque-transmitting mechanism has a friction actuator, which is operable to adjust the position of torque-transmitting members between the inner and outer race of the selectable one-way torque-transmitting mechanism. In an unactuated position of the friction actuator, the torque-transmitting members will permit rotation in one direction and prevent rotation in the opposite direction. In the actuated position, the torque-transmitting directional functions are reversed.

Abstract: A launch control system for a vehicle having an engine includes a clutch that selectively enables torque transfer from the engine. A control module determines a launch torque based on a throttle position and an engine speed to achieve a target engine stall speed. The control module determines a clutch torque based on the launch torque and that regulates engagement of the clutch based on the clutch torque.

Abstract: A two-mode, compound-split, electro-mechanical transmission utilizes an input member for receiving power from an engine, and an output member for delivering power from the transmission. First and second motor/generators are operatively connected to an energy storage device through a control for interchanging electrical power among the storage device, the first motor/generator and the second motor/generator. The transmission employs three planetary gear sets. Each planetary gear arrangement utilizes first, second and third gear members. The transmission also employs five torque-transmitting mechanisms. One of the five torque-transmitting mechanisms is contained within each of the first and second motor/generators.

Abstract: A speed sensor instability detection and correction system for use with a vehicle includes a speed sensor output variation extractor monitoring and recording change in output of a speed sensor over time. A speed sensor output variation comparison module detects speed sensor instability based on a comparison between the speed sensor output variation and a predetermined threshold. An output speed determination module selectively determines output speed in alternative ways based on whether speed sensor instability is detected.

Abstract: A method and apparatus to control acceleration of a vehicle equipped with an electrically variable transmission and including a regenerative braking system, each are operably connected to a vehicle driveline. The method and apparatus include determining which one of a preselected shift selector position for the transmission is commanded, and determining operator demand for acceleration, using inputs from throttle pedal and brake pedal. Vehicle acceleration is measured, and magnitude of commanded torque transferred from the electrically variable transmission and the regenerative braking system to the vehicle driveline is controlled based upon the commanded preselected shift selector position, the operator demand for acceleration, and the measured vehicle acceleration.

Abstract: The present invention provides a pressure control system having a control solenoid with plurality of coils disposed therein, and operable to provide a plurality of pressure gain characteristics to a torque-transmitting mechanism. By selectively energizing the individual coils or a combination thereof, multiple pressure gains may be achieved with a minimum of additional system hardware.

Abstract: Nine-speed transmissions are provided that include four planetary gear sets having six torque-transmitting mechanisms and various fixed interconnections to provide nine forward speed ratios and a reverse speed ratio. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another of the planetary gear members. The six torque-transmitting mechanisms are operated in combinations of two. Reduced component speeds and improved ratios are achieved.

Abstract: The method of the present invention is adapted to control transmission oil temperature. According to a preferred embodiment, the engine coolant temperature may be controlled in addition to or regardless of transmission oil temperature. To maintain transmission and/or engine temperature, the present invention is preferably configured to limit the engine's power when required to ensure the powertrain (engine and transmission) does not overheat.

Abstract: A vehicular powertrain has output torque established in accordance with various torque contributions in including throttle and brake torques. Throttle torque contribution is reduced proportionally to the amount of brake torque requested. Furthermore, such torque reductions are less aggressively applied with increasing throttle torques requested.

Abstract: A power transmission incorporates a plurality of torque-transmitting mechanisms having stationary piston torque-transmitting mechanisms. Each of the torque-transmitting mechanisms is controlled by one or more hydraulic master cylinders, which provide hydrostatic apply pressure for the respective torque-transmitting mechanisms. The control apparatus may incorporate either two or three master cylinders for controlling five torque-transmitting mechanisms through a plurality of selectively operable valve mechanisms.

Abstract: A multi-mode hybrid transmission has speed control provided via an open loop model derived as a function of preselected transmission accelerations and controlled and uncontrolled transmission torques. Motor torques are selected as the controlled torques and other preselected transmission torques are selected as the uncontrolled torques. The control also employs a closed loop control effort responsive to at least one preselected transmission speed error.

Abstract: The normal control of an electrically-activated hydraulic valve armature is overridden to automatically and periodically open the armature for flushing out debris that has accumulated between the armature and a seat that the armature is designed to engage. The valve develops fluid pressure for maintaining engagement of a motor vehicle transmission clutch, and when excessive slippage of the clutch is detected, the armature is forced into engagement with the seat until the slippage is reduced or a predetermined period of time has elapsed, after which the armature is temporarily positioned away from the seat to provide full flow of hydraulic fluid across the seat to flush out debris that prevents the armature from engaging the seat. During Neutral operation of the transmission, the armature is continuously positioned away from the seat, and during low torque conditions the armature is temporarily positioned away from the seat.

Abstract: A two-mode, compound-split, electro-mechanical transmission utilizes an input member for receiving power from an engine, and an output member for delivering power from the transmission. First and second motor/generators are operatively connected to an energy storage device through a control for interchanging electrical power among the storage device. The transmission employs three planetary gear sets that cooperate with a plurality of torque transmitting devices to provide two distinct gear trains or power paths corresponding to two modes of electrically variable operation in which the speed ratio between the input member and the output member varies with the speed of at least one of the motor/generators. The torque transmitting devices are selectively engageable to provide six discrete, fixed speed ratios.

Abstract: A hydraulic fluid storage apparatus for a transmission has a main sump and a secondary sump. The secondary sump is connected with the main sump through a restricted flow passage. The fluid within the main sump is subjected to centrifugal forces by rotating components within the transmission, such that at high speeds and high levels in the main sump, the restricted passage is closed by a centrifugal dam thereby resulting in fluid storage within the secondary sump. The fluid storage in the secondary sump returning to the main sump when the speed of the rotating components is reduced.

Abstract: The present invention provides a method for estimating the power capability of the primary power source of a hybrid vehicle. The method preferably includes calculating a first indicator based on a broadcast estimate from the primary power source of a hybrid vehicle. A second indicator is obtained by calculating the difference between the value of a torque command and the amount of torque reportedly delivered in response to the torque command. A third indicator is calculated based on a plurality of system dynamic equations. The first, second and third indicators are then combined to obtain an estimate of the power capability of the primary power source.