Method for determining input speed acceleration limits in a hybrid transmission

A method for controlling a powertrain system including an engine operatively connected to an input member of a transmission operative to transfer power between the input member and torque machines and an output member through selective application of torque transfer clutches, the torque machines connected to an energy storage device and the transmission operative in a continuously variable operating range state and a neutral state, the method comprising:

• selecting independently controllable parameters for the powertrain system;
• determining maximum and minimum motor torque constraints for the torque machines and determining maximum and minimum power constraints for the energy storage device;
• deriving equations for the independently controlled parameters based upon power outputs from the torque machines;
• deriving an equation for an independent parameter of interest based upon the power outputs from the torque machines;
• determining maximum and minimum states for the independently controllable parameters for the powertrain system;
• simultaneously solving the equations for the independently controlled parameters and the equation for the independent parameter of interest;
• and
• determining an achievable operating range for the parameter of interest based upon the simultaneously solved equations and the maximum and minimum states for the independently controllable parameters for the powertrain system, the maximum and minimum motor torque constraints for the torque machines and the maximum and minimum power constraints for the energy storage device.

A method for controlling a powertrain system including an engine operatively connected to an input member of a transmission operative to transfer power between the input member and torque machines and an output member through selective application of torque transfer clutches, the torque machines connected to an energy storage device and the transmission operative in a continuously variable operating range state and a neutral state, the method comprising:

• selecting independently controllable parameters for the powertrain system;
• determining maximum and minimum motor torque constraints for the torque machines and determining maximum and minimum power constraints for the energy storage device;
• deriving equations for the independently controlled parameters based upon torque outputs from the torque machines;
• deriving an equation for an independent parameter of interest based upon the torque outputs from the torque machines;
• determining maximum and minimum states for the independently controllable parameters for the powertrain system;
• simultaneously solving the equations for the independently controlled parameters and the equation for the independent parameter of interest;
• and
• determining an achievable operating range for the parameter of interest based upon the simultaneously solved equations and the maximum and minimum states for the independently controllable parameters for the powertrain system, the maximum and minimum motor torque constraints for the torque machines and the maximum and minimum power constraints for the energy storage device.