A method for controlling a powertrain comprising a transmission coupled to an engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically actuated torque transfer clutches includes filling one of the hydraulic clutches to a reference fill volume expected to create a touching state in the clutch, wherein the filling is accomplished through control of a pressure control solenoid, monitoring an actual fill time of the hydraulic clutch, monitoring a flow utilized in the filling, determining a measured fill volume based upon the actual fill time and the flow, calculating a fill volume error based upon the measured fill volume and the reference fill volume, and adjusting the reference fill volume based upon the fill volume error.

Method and apparatus to control clutch stroke volume in an electro-mechanical transmission

A method for operating a powertrain through selective application of a hydraulically actuated clutch includes monitoring a state of a pressure control switch operatively coupled the clutch, monitoring a hydraulic line pressure utilized by the pressure control switch to fill the clutch, determining a hydraulic flow rate flowing to the clutch based upon the state of the pressure control switch and the hydraulic line pressure, tracking a clutch fill volume of the clutch based upon the hydraulic flow rate, and controlling operation of the clutch based upon the clutch fill volume.

Method for model based clutch control and torque estimation

A powertrain system includes a transmission operative to transfer power between an input member and first and second torque machines and an output member. The first and second torque machines are connected to an energy storage device and the transmission is operative in a continuously variable operating range state. A method for controlling the powertrain system includes selecting an independently controllable parameter for the powertrain system, determining maximum and minimum motor torque constraints for the first and second torque machines and determining maximum and minimum power constraints for the energy storage device, determining maximum and minimum states for the independently controllable parameter for the powertrain system, and determining an achievable operating range for a parameter of interest based upon the maximum and minimum states for the independently controllable parameter for the powertrain system, the maximum and minimum motor torque constraints for the first and second torque machines and the maximum and minimum power constraints for the energy storage device.

Method for determining input speed acceleration limits in a hybrid transmission

A powertrain has an electrically variable hybrid transmission having an electro-hydraulic control system, plurality of electrical power units, and a plurality of torque transmitting mechanisms selectively engageable by the electro-hydraulic control system to provide four forward speed ranges, a neutral condition, an electric low speed mode, an electrically variable low and high speed mode, and two electrical power off drive home modes The electro-hydraulic control system includes a multiplexed pressure switch system The multiplexed pressure switch system of the present invention allows position detection of five torque transmitting mechanism control valves through the use of only four pressure switches

Multiplexed pressure switch system for an electrically variable hybrid transmission

In a pressure regulation valve having a main spool and a sub-spool slidably housed in the main spool, the main spool is at a position where pilot pressure force balances with a sum of pressure force of a feedback chamber and spring biasing force, when the pilot pressure is below a given value, so that normal output pressure proportional to pilot pressure is supplied to a hydraulic servo for driving a clutch of an automatic transmission, and, when the pilot pressure exceeds the given value, the sub-spool moves to a position where the feedback chamber communicates with a drain so that the main spool moves to a position where maximum output pressure equal to supply pressure source is supplied.

Pressure regulation valve

An improved shift control for a hydraulic automatic transmission in which the apply chamber of an on-coming clutch is filled in the preparation phase of the shift using a hydraulic flow rate model to estimate the volume of hydraulic fluid supplied to the apply chamber. In an initial portion of the fill interval, fluid is supplied to the apply chamber at a first elevated pressure, while continuously updating the fluid volume estimate. When the remaining un-filled volume of the apply chamber reaches a reference volume, the supply pressure is reduced to a second pressure at which the next phase of the shift is to be carried out. When the chamber volume is filled, the torque capacity of the clutch rises to a level corresponding to the second pressure, and the next phase of the shift automatically ensues.

Flow-based on-coming clutch fill control for an automatic transmission

A pressure control valve system for a friction device has a
regulator valve (14) with a plurality of pressure feedback differential areas (A1,A2) which
are selectively pressurized during the engagement of a friction device to
control the apply pressure at one rate during normal operation and at a higher
rate during high torque demand operation A plug valve (22) is disposed adjacent
the regulator valve (14) to establish two variable control forces acting on the
regulator valve in response to a variable control pressure The combination of
the differential areas and the plug valve permit the regulator valve to establish
two distinct pressure gain functions, each of which has a knee or inflection
point resulting in two pressure gain ratios

Pressure control valve

The power transmission has a fly-by-wire electro-hydraulic control mechanism that controls the engagement and disengagement of the range clutches in both forward and reverse operation In forward operation, the control mechanism permits continued vehicle operation in the third forward range should electrical discontinuance occur during the first through fourth forward ranges, and in the fifth forward range should electrical discontinuance occur in the fifth or sixth forward range Also, the control mechanism includes two logic valves and a forward on/off solenoid valve that permits the logic valves to control three torque-transmitting mechanisms with the use of two trim solenoid valves

Fly-by-wire electro-hydraulic control mechanism for a six speed transmission

An improved and self-diagnosing shift pressure regulator apparatus for an automatic shift transmission provides a diagnostic output that reliably and timely detects initiation and cessation of fluid supply to a friction element. The regulator apparatus includes a pressure regulator valve responsive to an electronically developed pilot pressure, and a diagnostic switch. The pilot pressure positions the pressure regulator valve in one of three states—ON, TRIM, and OFF—and the diagnostic switch is continuously activated by a control pressure whenever the pressure regulator valve is in the TRIM or ON states.

Self-diagnosing pressure regulator apparatus

The present invention is directed to a retarder control system for protection against transmission overspeed. The system operates in conjunction with a rotatable input member and an output member that is rotatable relative to the input member. A torque transfer device is operatively connected between the relatively rotatable input and output members. Specifically, a piston assembly is operated by an input control chamber that selectively receives pressurized hydraulic fluid which effects translation of the piston assembly to actuate the torque transfer device and thereby effect a driving connection between the relatively rotatable input and output members. The present system is adapted to control a hydrodynamic retarder assembly having a work cavity to receive hydraulic fluid. The retarder input valve assembly is supported from one of the relatively rotatable members selectively to deliver pressurized hydraulic fluid from the input control chamber to the retarder cavity. In order to achieve overspeed protection the retarder input valve opens in response to a predetermined angular velocity of the relatively rotatable member on which the retarder input valve assembly is supported. In a variation of the retarder control system explained above, a dump valve assembly is provided which opens selectively to release pressurized hydraulic fluid from the work cavity of said retarder in response to the pressure of the hydraulic fluid within said retarder work cavity.

Martin Robert Dadel

Papers

Flow-based on-coming clutch fill control for an automatic transmission

Pressure control valve

Fly-by-wire electro-hydraulic control mechanism for a six speed transmission

Self-diagnosing pressure regulator apparatus

System for transmission overspeed and horsepower limit protection