Abstract:
A hybrid vehicle includes an engine and an electric machine, both capable of propelling the vehicle. The electric machine provides creep torque to propel the vehicle at a slow speed or hold the vehicle when on an incline. At least one controller is programmed to cancel or otherwise inhibit the electric machine from generating the creep torque in response to a brake torque or brake torque request exceeding a calibratible threshold. The calibratible threshold varies based upon vehicle incline, vehicle mass, and/or vehicle speed.
Abstract:
A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a torque output of an electric machine of an electrified vehicle based on estimated loads present during a transmission engagement of the electrified vehicle.
Abstract:
Systems and methods for improving emissions and drivability of a hybrid vehicle that includes a motor/generator and an engine are presented. The systems and methods may allow vehicle emissions regulations to be met while at the same time providing driveline torque that matches driver demand torque so that vehicle drivability may be maintained or improved.
Abstract:
Systems and methods for transitioning a torque source between speed control and torque control modes during a vehicle creep mode are disclosed. In one example, torque of an electric machine is adjusted in response to a torque converter model. The torque converter model provides for a locked or unlocked torque converter clutch.
Abstract:
A vehicle includes a powertrain having an engine and an electric machine (M/G) connected by an upstream clutch, and a gearbox connected to the M/G by a torque converter. A controller is configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the engine at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency. A method is provided for controlling a vehicle. In response to a Park or Neutral gear selection and an electrical power request from the M/G, the engine is operated at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency.
Abstract:
A hybrid vehicle powertrain is configured to provide a regenerative-braking torque limit on a transmission during a regenerative-braking downshift. The regenerative-braking downshift event has sequential boost, start, torque, inertia, and end phases. The transmission may be operated in absence of a regenerative-braking torque limit during the boost and start phases to recapture more energy. The transmission may be operated with a regenerative-braking torque limit during the torque and inertia phases to protect for an input shaft speed dip that may occur without the limit. The limit may be removed once the regenerative-braking downshift event is completed.
Abstract:
Systems and methods for improving efficiency of a hybrid vehicle are presented. In one example, an electric machine provides at least a portion of a driver demand torque to propel a vehicle. Operation of the electric machine is adjusted to avoid conditions where efficiency of the electric machine is less than desired.
Abstract:
Systems and methods for improving operation of a hybrid vehicle are presented. In one example, a difference between estimated torque output of an active torque source in a driveline and actual torque output of the active torque source is mitigated via entering a driveline speed control mode. The methods and systems may be useful when switching between different driveline modes of operation.
Abstract:
A hybrid electric vehicle has a traction motor, a driveline connected to a vehicle wheel, and a controller. The controller is configured to control motor torque through a region surrounding vehicle wheel torque reversal, control driveline input torque during torque reversal of driveline output torque to limit rate of change of driveline output torque, and control motor torque during a torque reversal of at least one driveline component to limit rate of change of the torque applied to the driveline component. A method for controlling a vehicle having a traction motor includes controlling the traction motor torque through a region surrounding a vehicle wheel torque reversal, controlling driveline input torque during torque reversal of driveline output torque to limit rate of change of output torque, and controlling traction motor torque during a torque reversal of a powertrain component to limit rate of change of the torque applied to the component.
Abstract:
Systems and methods for learning torque estimate errors and updating torque estimation models are presented. In one example, torque errors are learned during an engine shut-down, after a disconnect clutch coupled between an engine and an electric machine has been released. An updated torque estimation model is then used to control torque during subsequent engine operation to improve drive feel and vehicle performance.