Abstract: A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.

Abstract: A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.

Abstract: A method for optimizing torque control in a vehicle having a controller and a rotating member includes generating a closed-loop total proportional torque command using a state space feedback portion of the controller, and splitting the total proportional torque command into high-frequency and low-frequency proportional torque components. A total proportional torque is passed to the rotating member to provide driveline damping control when speed control is not required. The high-frequency proportional torque component is passed to the rotating member to provide driveline damping control, and the low-frequency torque component is passed with a total integral torque command to the rotating member to provide speed control, when speed control is required. A vehicle includes a controller having proportional-integral control capabilities and a state space observer, and a powertrain having a rotating member whose speed and damping characteristics are controlled by the controller.

Abstract: A method for controlling a hybrid electric vehicle having a control system, a traction motor, and an engine includes generating an activation signal during a predetermined vehicle maneuver. The predetermined vehicle maneuver is a threshold hard braking maneuver on a surface having a low coefficient of friction. The method also includes processing the activation signal using the control system, and using the traction motor to command an injection or a passing of a feed-forward torque to the driveline of the vehicle. The feed-forward torque is in the same direction as the engine torque, and prevents a drive shaft of the engine from spinning in reverse during the maneuver. The method may include generating the activation signal in response to detecting an active state of the ABS controller. A hybrid electric vehicle includes an engine, a traction motor, and a control system configured to execute the above method.

Abstract: A powertrain system includes a torque machine mechanically rotatably coupled via a transfer gear set to a drive wheel. The transfer gear set includes a first gear meshingly engaged to a second gear with lash angle between the first and second gears. A method for operating the powertrain system includes monitoring an output speed associated with the torque machine and a wheel speed associated with the drive wheel. A transition between a first torque transfer state and a second torque transfer state is detected, the transition including a gear lash event across the transfer gear set. An elapsed time period for completing the gear lash event across the transfer gear set during the transition between the first torque transfer state and the second torque transfer state is set, and a target output speed derived from the wheel speed during and at the end of the elapsed time period is determined.

Abstract: A powertrain system includes a torque machine mechanically rotatably coupled via a transfer gear set to a drive wheel. The transfer gear set includes a first gear meshingly engaged to a second gear with lash angle between the first and second gears. A method for operating the powertrain system includes monitoring an output speed associated with the torque machine and a wheel speed associated with the drive wheel. A transition between a first torque transfer state and a second torque transfer state is detected, the transition including a gear lash event across the transfer gear set. An elapsed time period for completing the gear lash event across the transfer gear set during the transition between the first torque transfer state and the second torque transfer state is set, and a target output speed derived from the wheel speed during and at the end of the elapsed time period is determined.

Abstract: A method for controlling a hybrid electric vehicle having a control system, a traction motor, and an engine includes generating an activation signal during a predetermined vehicle maneuver. The predetermined vehicle maneuver is a threshold hard braking maneuver on a surface having a low coefficient of friction. The method also includes processing the activation signal using the control system, and using the traction motor to command an injection or a passing of a feed-forward torque to the driveline of the vehicle. The feed-forward torque is in the same direction as the engine torque, and prevents a drive shaft of the engine from spinning in reverse during the maneuver. The method may include generating the activation signal in response to detecting an active state of the ABS controller. A hybrid electric vehicle includes an engine, a traction motor, and a control system configured to execute the above method.

Abstract: A method for optimizing torque control in a vehicle having a controller and a rotating member includes generating a closed-loop total proportional torque command using a state space feedback portion of the controller, and splitting the total proportional torque command into high-frequency and low-frequency proportional torque components. A total proportional torque is passed to the rotating member to provide driveline damping control when speed control is not required. The high-frequency proportional torque component is passed to the rotating member to provide driveline damping control, and the low-frequency torque component is passed with a total integral torque command to the rotating member to provide speed control, when speed control is required. A vehicle includes a controller having proportional-integral control capabilities and a state space observer, and a powertrain having a rotating member whose speed and damping characteristics are controlled by the controller.