Abstract:
A vehicle includes a step-ratio automatic transmission having clutches engageable to provide forward and reverse gears, an electric machine selectively coupled to the transmission, a main pump powered by the electric machine and supplying oil to actuate selected transmission clutches, a gear selector configured for selecting a transmission gear, and a controller configured to stop the electric machine when the gear selector selects park or neutral, to operate the electric machine in a speed control mode using a higher controller gain in response to the gear selector selecting forward or reverse while the electric machine is stopped until the electric machine and the main pump reach a first speed threshold to reduce engagement delay of at least one of the transmission clutches, and to operate the electric machine using a lower controller gain when the electric machine and the main pump exceed the first speed threshold.
Abstract:
A vehicle includes a powertrain and at least one controller programmed to, in response to a brake request and a shaft speed associated with a speed of the vehicle achieving a starting speed that is defined by a torque of the powertrain that changes with brake demand at a given shaft speed, reduce a regenerative torque limit that constrains regenerative braking torque over a blend-out duration based on the shaft speed.
Abstract:
A vehicle includes a powertrain having an electric machine configured to selectively apply regenerative braking torque to decelerate the vehicle. The vehicle also includes a controller programmed to control a rate of change of a regenerative braking torque limit during a transmission downshift that occurs during a regenerative braking event based on a change in speed of an output shaft of the powertrain caused by the transmission downshift.
Abstract:
A vehicle includes a powertrain having an electric machine configured to selectively apply regenerative torque to cause deceleration in response to braking demand; the powertrain further including a torque converter configured to decouple the electric machine from wheels of the vehicle. The vehicle is also provided with a controller programmed to, during a regenerative braking event, receive a signal defining a regenerative torque limit, and in response to a fault condition associated with the regenerative torque limit, generate a replacement regenerative torque limit based upon a torque converter open speed to decrease roughness during transitions into and out of regenerative braking.
Abstract:
A hybrid electric vehicle includes an engine and an electric machine, both capable of providing propulsion power. A clutch is configured to selectively couple the engine to the electric machine. At times, the vehicle may be subject to excessive loads, such as a large amount of weight in the vehicle or the vehicle towing another object. At least one controller is programmed to engage the clutch and start the engine in response to a load of the vehicle exceeding a predetermined threshold and a release of the brake pedal while the vehicle is stopped and in drive. This increases available engine torque prior to vehicle launch in anticipation of an upcoming acceleration demand.
Abstract:
A vehicle is provided with a powertrain including an electric motor, an internal combustion engine, and a turbocharger. The vehicle further includes a controller programmed to apply a variable filter to engine torque commands that are responsive to driver demand. The filter affects commands having a rate of increase greater than a predetermined threshold such that corresponding rates of increase in both engine torque and turbocharger speed are limited to respective rates less than the maximum available levels in order to reduce a surge in engine output emissions. The controller additionally issues commands for motor torque such that overall powertrain torque satisfies the driver demand.
Abstract:
A vehicle includes an engine having a crankshaft, a transmission having an input, and a torque converter mechanically coupled to the input. The vehicle further includes an electric machine mechanically coupled to the torque converter, a clutch configured to mechanically couple the electric machine and crankshaft, and one or more controllers. The one or more controllers are programmed to, in response to the transmission being in a drive or reverse gear and a speed of the vehicle being less than a predetermined value in an absence of driver demand, control the electric machine to achieve a target speed to cause the torque converter to output torque such that the speed of the vehicle approaches a generally constant speed less than or equal to the predetermined value when the vehicle is on a generally flat grade.
Abstract:
A vehicle comprises a hybrid powertrain includes an electric machine coupled between an automatic gearbox and an engine. The vehicle includes paddle shifters configured to output a driver requested gear change. The hybrid powertrain is configured to selectively operate in an economy mode that optimizes fuel economy. While operating in the economy mode, a controller may selectively inhibit the driver requested gear change when the change may negatively impact fuel economy. In the economy mode, the driver requested gear change may be inhibited during a demand for braking. If the driver requested gear change is a downshift request, the downshift is inhibited and simulated using electric machine torque.
Abstract:
A method of controlling a hybrid vehicle includes commanding a first electric machine to provide a compensating torque. The compensating torque is based on a calculated cylinder pressure. The calculated cylinder pressure is calculated using a dynamic model. The model has an initializing input of engine crank position and real-time inputs of measured speed of the first electric machine and measured speed of the second electric machine.
Abstract:
In at least one embodiment, a vehicle powertrain includes an engine and an electric machine mechanically coupled by a clutch. The powertrain also includes a torque converter configured to fluidly couple the electric machine to an output shaft. A controller is programmed to command a rotational speed output of the electric machine to the torque converter based on a predicted torque delivered across the clutch. The controller is further programmed to modify the command based on a difference between the commanded rotational speed output and an actual rotational speed output of the electric machine.