Abstract: A method of automatically starting an internal combustion engine of a hybrid vehicle includes defining a rotational engine speed profile to represent a desired engine speed during a starting event with a hybrid system controller, and communicating the rotational engine speed profile to an engine controller. The internal combustion engine is rotated with an electric propulsion motor of the hybrid vehicle. A spark correction offset is calculated with the engine controller based on the rotational engine speed profile. The internal combustion engine is fired with the calculated spark correction offset for a pre-determined number of firing events, with the engine controller, as the rotational speed of the engine increases. The rotational speed of the internal combustion engine is controlled with the hybrid system controller after the pre-determined number of firing events.

Abstract: A method of automatically starting an internal combustion engine of a hybrid vehicle includes defining a rotational engine speed profile to represent a desired engine speed during a starting event with a hybrid system controller, and communicating the rotational engine speed profile to an engine controller. The internal combustion engine is rotated with an electric propulsion motor of the hybrid vehicle. A spark correction offset is calculated with the engine controller based on the rotational engine speed profile. The internal combustion engine is fired with the calculated spark correction offset for a pre-determined number of firing events, with the engine controller, as the rotational speed of the engine increases. The rotational speed of the internal combustion engine is controlled with the hybrid system controller after the pre-determined number of firing events.

Abstract: A method for controlling a hybrid powertrain includes monitoring input torque of an input member and may include determining an oscillation torque. The method monitors critical vehicle characteristics, including at least a transmission operating mode and an input speed, and operates the powertrain at the input torque. The method compares input torque to a minimum threshold or oscillation torque to a fatigue threshold and identifies a first critical event, which occurs when input torque exceeds the minimum threshold or oscillation torque exceeds the fatigue threshold. The method identifies a first peak with the on-board controller during the first critical event. Peak events occur when the monitored input torque or oscillation torque changes between positive and negative slope. The method identifies a first CVC set occurring with the first peak and may record the first CVC set and the first peak in a look-up table.

Abstract: A method for controlling a multi-mode transmission system employing torque machines under dynamic operating conditions includes calculating a phase shift between a control parameter of one of the torque machines and a response parameter of the multi-mode transmission system under dynamic operating conditions, comparing the calculated phase shift and an expected phase shift, and executing remedial action when the calculated phase shift exceeds a threshold associated with the expected phase shift.

Abstract: A method for controlling a hybrid powertrain includes monitoring input torque of an input member and may include determining an oscillation torque. The method monitors critical vehicle characteristics, including at least a transmission operating mode and an input speed, and operates the powertrain at the input torque. The method compares input torque to a minimum threshold or oscillation torque to a fatigue threshold and identifies a first critical event, which occurs when input torque exceeds the minimum threshold or oscillation torque exceeds the fatigue threshold. The method identifies a first peak with the on-board controller during the first critical event. Peak events occur when the monitored input torque or oscillation torque changes between positive and negative slope. The method identifies a first CVC set occurring with the first peak and may record the first CVC set and the first peak in a look-up table.

Abstract: A powertrain system includes a multi-mode transmission configured to transfer torque among an input member, torque machines and an output member. A method for controlling operation of the multi-mode transmission includes determining torque commands for the torque machines in response to a desired input speed of the input member and an output speed of the output member determined based upon an estimated wheel speed of a wheel of a driveline coupled to the output member. The estimated wheel speed of the wheel is set equal to a monitored wheel speed of the wheel upon detecting an abrupt decrease in the wheel speed. Torque commands are determined for the torque machines in response to the desired input speed and the monitored wheel speed.

Abstract: A method for optimizing a shift event in a vehicle includes designating a clutch to be used as an oncoming clutch or an offgoing clutch in the shift event before executing the shift event, and processing a plurality of input values through a state observer to thereby determine, as an output value of the state observer, an estimated slip speed of the designated clutch. The method includes using a proportional-integral control module for the designated clutch (a clutch PI) to close the control loop on the estimated slip speed from the state observer, thereby smoothing a switching between state space equations in the state observer, and executing the shift event. A vehicle includes a transmission, an engine, at least one traction motor, and a control system configured for executing the above method.

Abstract: A powertrain system includes a multi-mode transmission having a plurality of torque machines. A method for controlling the powertrain system includes identifying all presently applied clutches including commanded applied clutches and the stuck-closed clutch upon detecting one of the torque-transfer clutches is in a stuck-closed condition. A closed-loop control system is employed to control operation of the multi-mode transmission accounting for all the presently applied clutches.

Abstract: A method for controlling a multi-mode transmission system employing torque machines under dynamic operating conditions includes calculating a phase shift between a control parameter of one of the torque machines and a response parameter of the multi-mode transmission system under dynamic operating conditions, comparing the calculated phase shift and an expected phase shift, and executing remedial action when the calculated phase shift exceeds a threshold associated with the expected phase shift.

Abstract: A powertrain system includes a multi-mode transmission having a plurality of torque machines. A method for controlling the powertrain system includes identifying all presently applied clutches including commanded applied clutches and the stuck-closed clutch upon detecting one of the torque-transfer clutches is in a stuck-closed condition. A closed-loop control system is employed to control operation of the multi-mode transmission accounting for all the presently applied clutches.

Abstract: A powertrain system includes a multi-mode transmission configured to transfer torque among an input member, torque machines and an output member. A method for controlling operation of the multi-mode transmission includes determining torque commands for the torque machines in response to a desired input speed of the input member and an output speed of the output member determined based upon an estimated wheel speed of a wheel of a driveline coupled to the output member. The estimated wheel speed of the wheel is set equal to a monitored wheel speed of the wheel upon detecting an abrupt decrease in the wheel speed. Torque commands are determined for the torque machines in response to the desired input speed and the monitored wheel speed.

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 of controlling a vehicle changing operating ranges from a first range to a second range includes defining a current set of state equations and a target set of state equations. The current set of state equations and the target set of state equations may each include a set of control state equations for controlling the vehicle and a set of estimator state equations for estimating the performance of the vehicle. The values of the current set of state equations are incrementally adjusted over time until substantially equal to values of the target set of state equations to smooth the requested change between the first range and the second range.

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 of controlling a vehicle changing operating ranges from a first range to a second range includes defining a current set of state equations and a target set of state equations. The current set of state equations and the target set of state equations may each include a set of control state equations for controlling the vehicle and a set of estimator state equations for estimating the performance of the vehicle. The values of the current set of state equations are incrementally adjusted over time until substantially equal to values of the target set of state equations to smooth the requested change between the first range and the second range.

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: The present invention provides an improved method and apparatus for regulating active damping in a hybrid vehicle powertrain. The method includes: monitoring the damping command sent to the active damping system; determining a mean reference point, which may be a filtered value of the damping torque command; determining if the unfiltered damping torque command value switches from one side to the other of the mean reference point; if a switch is detected, determining if the size of the switch exceeds a predetermined minimum; if it does, then increasing a total number of switches; determining if the total number of switches exceeds a switch threshold; if the total number of switches exceeds the switch threshold, determining if the current damping torque exceeds a damping torque threshold; and decreasing the damping torque if the total number of switches exceeds the switch threshold and the current damping torque exceeds the damping torque threshold.

Abstract: A method for optimizing a shift event in a vehicle includes designating a clutch to be used as an oncoming clutch or an offgoing clutch in the shift event before executing the shift event, and processing a plurality of input values through a state observer to thereby determine, as an output value of the state observer, an estimated slip speed of the designated clutch. The method includes using a proportional-integral control module for the designated clutch (a clutch PI) to close the control loop on the estimated slip speed from the state observer, thereby smoothing a switching between state space equations in the state observer, and executing the shift event. A vehicle includes a transmission, an engine, at least one traction motor, and a control system configured for executing 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.

Abstract: The present invention provides an improved method and apparatus for regulating state variable estimators used in a hybrid active damping system for a vehicle powertrain. The state estimator provides variable estimates for operating states, such as real-time torque values of axles and dampers, that are not readily measurable with production powertrain and driveline hardware. This facilitates implementation of other control algorithms, such as torque oscillation damping control schemes which use multivariable feedback. The apparatus and method monitors the operating mode of the powertrain, and resets the state estimator for the hybrid active damping ring (HADR) under predetermined operating conditions. For instance, the state estimator includes an array of current state and predicted state variables that are set equal to corresponding reference values or measured values if the powertrain enters into four-wheel drive low (4WDLO).