Abstract: 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.

Abstract: A powertrain system includes an engine coupled to an input member of a transmission operative to transmit power between the input member, a torque machine and an output member. The torque machine is connected to an energy storage device. The engine is selectively operative in engine states comprising an engine-on state and an engine-off state. A method for controlling a powertrain system includes determining a first power range for output power of the energy storage device, commanding the engine to transition from a first engine state to a second engine state, and expanding the first power range of the energy storage device and controlling the torque machine based upon the expanded power range of the energy storage device during the transition from the first engine state to the second engine state.

Abstract: There is provided a control scheme for restarting an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method includes generating a torque output from an electrical machine to rotate the engine, and determining an engine crank torque. The torque output from the electrical machine is selectively controlled based upon the engine crank torque. The engine is fired when rotational speed of the engine exceeds a threshold. An engine torque simulation model accurately determines engine compression pressures in real-time to accommodate changes in engine operating conditions, based upon present engine operating conditions.

Abstract: There is provided a method and apparatus to determine operating conditions for a powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween. The method comprises determining a torque output and an operating cost for operating the first and second electrical machines of the hybrid transmission effective to meet an operator torque request when the engine is operating in an engine-off operating state. Determining the torque output for operating the first and second electrical machines comprises executing a predetermined system equation effective to determine motor torque outputs from each of the first and second electrical machines based upon the selected parametric value for the input torque and the operator torque request.

Abstract: A control system for a hybrid powertrain which determines engine crank angle position based upon signal inputs from electric machines of the powertrain is provided. The hybrid powertrain comprises an internal combustion engine and electric machines and an electro-mechanical transmission selectively operative to transmit torque therebetween. The electric machines are rotatably fixedly coupled to the internal combustion engine via a transmission input shaft. Control modules are adapted to execute a control scheme to determine engine crank angle position. The control scheme comprises code to determine an input shaft angle based upon rotational positions of the electric machines. An offset angle of the input shaft and an angular twist between the engine and the transmission are determined. An engine crank angle offset is determined based upon the offset angle and the angular twist of the input shaft.

Abstract: The invention comprises a method, an article, and a control system for controlling a powertrain having a main and an auxiliary hydraulic pump, with each pump operative to supply hydraulic fluid to a hydraulic circuit of the transmission. It includes determining a main pressure and a desired main pressure, and controlling the auxiliary hydraulic pump. Determining a main pressure in the hydraulic circuit comprises estimating hydraulic pressure. The auxiliary pump is controlled to an operating speed. Control of flow from the auxiliary and main pumps can comprise an exclusive ‘either-or’ flow, or a blended flow.

Abstract: A method and an apparatus for controlling an electro-mechanical transmission selectively operative in a plurality of fixed gear modes and continuously variable modes is provided. The exemplary transmission comprises first and second electrical machines and a hydraulic circuit comprising a plurality of pressure control devices and flow management valves. The method comprises monitoring an operating temperature of the electrical machines. A cooling flow rate in the hydraulic circuit effective to reduce the operating temperature of the electrical machines is determined. Availability of active cooling for each of the electrical machines is determined. Hydraulic flow in the hydraulic circuit is selectively controlled.

Abstract: A powertrain system includes an engine coupled to an input member of a transmission operative to transmit power between the input member, a torque machine and an output member. The torque machine is connected to an energy storage device. The engine is selectively operative in engine states comprising an engine-on state and an engine-off state. A method for controlling a powertrain system includes determining a first power range for output power of the energy storage device, commanding the engine to transition from a first engine state to a second engine state, and expanding the first power range of the energy storage device and controlling the torque machine based upon the expanded power range of the energy storage device during the transition from the first engine state to the second engine state.

Abstract: An article of manufacture and method are provided to determine pressure in an unfired cylinder of an internal combustion engine. The cylinder comprises a variable volume combustion chamber defined by a piston reciprocating within a cylinder between top-dead center and bottom-dead center points and an intake valve and an exhaust valve controlled during repetitive, sequential exhaust, intake, compression and expansion strokes of said piston. The code is executed to determine volume of the combustion chamber, and determine positions of the intake and exhaust valves. A parametric value for cylinder pressure is determined at each valve transition. Cylinder pressure is estimated based upon the combustion chamber volume, positions of the intake and exhaust valves, and the cylinder pressure at the most recently occurring valve transition.

Abstract: 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.

Abstract: A method of regulating a torque output of an internal combustion engine in a hybrid electric vehicle includes determining whether a cam phaser system of the engine is in one of an inactive state and an active state and monitoring at least one engine operating parameter. An engine torque array is selected from a plurality of engine torque arrays based on the one of the inactive state and the active state. An available engine torque is determined based on the engine torque array and the at least one engine operating parameter and the engine is regulated based on the available engine torque.

Abstract: A control scheme is provided for stopping an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method, executed as program code in an article of manufacture comprises the following steps in the sequence set forth. First, engine operation is controlled to stop firing the engine. A damper clutch is controlled to lock rotation of the engine and the electro-mechanical transmission. Torque outputs from the first and second electrical machines are then selectively controlled to reduce engine speed. Torque outputs from the first and second electrical machines are then selectively controlled to stop rotation of the engine substantially near a predetermined crank position.

Abstract: There is provided a method and apparatus to determine operating conditions for a powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween. The method comprises determining a torque output and an operating cost for operating the first and second electrical machines of the hybrid transmission effective to meet an operator torque request when the engine is operating in an engine-off operating state. Determining the torque output for operating the first and second electrical machines comprises executing a predetermined system equation effective to determine motor torque outputs from each of the first and second electrical machines based upon the selected parametric value for the input torque and the operator torque request.

Abstract: A method of regulating a torque output of an internal combustion engine in a hybrid electric vehicle includes determining whether a cam phaser system of the engine is in one of an inactive state and an active state and monitoring at least one engine operating parameter. An engine torque array is selected from a plurality of engine torque arrays based on the one of the inactive state and the active state. An available engine torque is determined based on the engine torque array and the at least one engine operating parameter and the engine is regulated based on the available engine torque.

Abstract: There is provided a control scheme for restarting an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method comprises generating a torque output from an electrical machine to rotate the engine, and determining an engine crank torque. The torque output from the electrical machine is selectively controlled based upon the engine crank torque. The engine is fired when rotational speed of the engine exceeds a threshold. An engine torque simulation model accurately determines engine compression pressures in real-time to accommodate changes in engine operating conditions, based upon present engine operating conditions.

Abstract: A control scheme is provided for stopping an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method, executed as program code in an article of manufacture comprises the following steps in the sequence set forth. First, engine operation is controlled to stop firing the engine. A damper clutch is controlled to lock rotation of the engine and the electro-mechanical transmission. Torque outputs from the first and second electrical machines are then selectively controlled to reduce engine speed. Torque outputs from the first and second electrical machines are then selectively controlled to stop rotation of the engine substantially near a predetermined crank position.

Abstract: A control system for a hybrid powertrain which determines engine crank angle position based upon signal inputs from electric machines of the powertrain is provided. The hybrid powertrain comprises an internal combustion engine and electric machines and an electromechanical transmission selectively operative to transmit torque therebetween. The electric machines are rotatably fixedly coupled to the internal combustion engine via a transmission input shaft. Control modules are adapted to execute a control scheme to determine engine crank angle position. The control scheme comprises code to determine an input shaft angle based upon rotational positions of the electric machines. An offset angle of the input shaft and an angular twist between the engine and the transmission are determined. An engine crank angle offset is determined based upon the offset angle and the angular twist of the input shaft.

Abstract: An article of manufacture and method are provided to determine pressure in an unfired cylinder of an internal combustion engine. The cylinder comprises a variable volume combustion chamber defined by a piston reciprocating within a cylinder between top-dead center and bottom-dead center points and an intake valve and an exhaust valve controlled during repetitive, sequential exhaust, intake, compression and expansion strokes of said piston. The code is executed to determine volume of the combustion chamber, and determine positions of the intake and exhaust valves. A parametric value for cylinder pressure is determined at each valve transition. Cylinder pressure is estimated based upon the combustion chamber volume, positions of the intake and exhaust valves, and the cylinder pressure at the most recently occurring valve transition.

Abstract: A method and an apparatus for controlling an electro-mechanical transmission selectively operative in a plurality of fixed gear modes and continuously variable modes is provided. The exemplary transmission comprises first and second electrical machines and a hydraulic circuit comprising a plurality of pressure control devices and flow management valves. The method comprises monitoring an operating temperature of the electrical machines. A cooling flow rate in the hydraulic circuit effective to reduce the operating temperature of the electrical machines is determined. Availability of active cooling for each of the electrical machines is determined. Hydraulic flow in the hydraulic circuit is selectively controlled.

Abstract: The invention comprises a method, an article, and a control system for controlling a powertrain having a main and an auxiliary hydraulic pump, with each pump operative to supply hydraulic fluid to a hydraulic circuit of the transmission. It includes determining a main pressure and a desired main pressure, and controlling the auxiliary hydraulic pump. Determining a main pressure in the hydraulic circuit comprises estimating hydraulic pressure. The auxiliary pump is controlled to an operating speed. Control of flow from the auxiliary and main pumps can comprise an exclusive ‘either-or’ flow, or a blended flow.