Abstract:
Systems for managing downshifts in hybrid-electric vehicles are disclosed. The systems include a multispeed transmission, an internal combustion engine selectively coupled to the multispeed transmission, an electric motor coupled to the multispeed transmission, and an electronic control unit. The electronic control unit is programmed to evaluate a torque demand, start the internal combustion engine, and pre-stage a downshift shift sequence by partially disengaging a second shift clutch and partially engaging a first shift clutch. The electronic control unit is also programmed to interrupt the downshift shift sequence until a pre-determined torque supplemental event occurs and later complete the downshift shift sequence by modifying the hydraulic pressure through the valve body to completely disengage a second gear set from the input shaft with the second shift clutch and completely engage a first gear set and the input shaft with the first shift clutch.
Abstract:
Systems for managing downshifts in hybrid-electric vehicles are disclosed. The systems include a multispeed transmission, an internal combustion engine selectively coupled to the multispeed transmission, an electric motor coupled to the multispeed transmission, and an electronic control unit. The electronic control unit is programmed to evaluate a torque demand, start the internal combustion engine, and pre-stage a downshift shift sequence by partially disengaging a second shift clutch and partially engaging a first shift clutch. The electronic control unit is also programmed to interrupt the downshift shift sequence until a pre-determined torque supplemental event occurs and later complete the downshift shift sequence by modifying the hydraulic pressure through the valve body to completely disengage a second gear set from the input shaft with the second shift clutch and completely engage a first gear set and the input shaft with the first shift clutch.
Abstract:
Systems and methods for improving transmission shifting of a hybrid vehicle are presented. In one example, output torque of an electric machine is adjusted in response to a downshift of a fixed step ratio transmission during regenerative braking. The output torque of the electric machine may be adjusted in response to a phase of the transmission shift.
Abstract:
A transmission shift is timed for a hybrid electric powertrain as a function of a torque capacity of an electric machine relative to a shifting torque required to change gearings of a transmission. A vehicle is being propelled by the machine, with an engine stopped, when the shift is requested. If the machine has insufficient torque capacity to change transmission gearings, then the shift request is delayed until the engine has started.
Abstract:
Systems and methods for improving operation of a hybrid vehicle driveline are presented. In one example, a margin torque for closing a torque converter clutch is adjusted responsive to a state of engine operation.
Abstract:
A system and method for controlling a hybrid vehicle having an engine selectively coupled by an upstream clutch to an electric machine, which is selectively coupled by a downstream clutch to a step-ratio transmission, include at least one controller programmed to control the engine and the electric machine in response to entering a lash zone in anticipation of a wheel torque reversal to adjust a gain applied to an active motor damping torque controller to reduce driveline oscillations and backlash.
Abstract:
A transmission shift is timed for a hybrid electric powertrain as a function of a torque capacity of an electric machine relative to a shifting torque required to change gearings of a transmission. A vehicle is being propelled by the machine, with an engine stopped, when the shift is requested. If the machine has insufficient torque capacity to change transmission gearings, then the shift request is delayed until the engine has started.
Abstract:
A vehicle includes an engine and an electric machine coupled to a gearbox through a torque converter. The vehicle includes a controller programmed to command an engine torque and an electric machine torque to achieve a predetermined positive torque at the input of the torque converter when a driver demand torque at the torque converter input decreases to fall within a range between the predetermined positive torque and a predetermined negative torque.
Abstract:
A vehicle includes and an engine, a motor, a transmission, and a controller. The transmission is configured is to receive power from the engine and the motor. The transmission is also configured to shift between gears based on a shift schedule. The controller is programmed to, in response to only the motor providing power to the transmission, adjust the shift schedule to narrow an operating speed range of the motor such that the motor speed maintains a peak range of an available motor power output.
Abstract:
A vehicle includes a powertrain and a controller. The powertrain includes a transmission mechanically coupled to an electric machine and configured to transfer torque between a wheel and the electric machine. The transmission has a gearbox configured to establish gear ratios through a shift. The controller is programmed to, in response to an indication of an expected regenerative braking event having a timing falling within a shift window of the transmission, prevent a clutch of the transmission from disengaging until first occurrence of application of an accelerator pedal or removal of the indication to inhibit the shift prompted by a shift schedule of the gearbox.