Control architecture and method for two-dimensional optimization of input speed and input torque in mode for a hybrid powertrain system
View Patent ↗There is provided a control system for a powertrain system including an electro-mechanical transmission that is selectively operative in a plurality of fixed gear modes and continuously variable modes. The control system is adapted to execute the following steps, comprising determining a range of permissible engine input speeds and a range of permissible engine input torques, and determining motor input torques for the first and second electrical machines based upon the range of permissible engine input speeds and the range of permissible engine input torques. A cost is determined for each of the motor input torques. A preferred engine input speed and a preferred engine input torque are identified based upon the costs for the motor input torques.
1. Method for identifying preferred operating conditions for a powertrain, comprising:
determining ranges of permissible inputs to a transmission;
determining a plurality of motor torques input from first and second electrical machines to the transmission, each associated with one of the permissible inputs to the transmission and responsive to an output torque command;
determining a plurality of operating costs based on inputs comprising the plurality of motor torques input from the first and second electrical machines to the transmission, the ranges of permissible inputs to the transmission and costs related to fuel economy, emissions and battery life, each operating cost associated with one of the motor torques input from the first and second electrical machines to the transmission and the associated permissible input to the transmission responsive to the output torque command; and,
identifying a preferred input to the transmission responsive to the output torque command based upon the determined plurality of operating costs comprising identifying an input to the transmission and the motor torques input from the first and second machines corresponding to a minimum operating cost, wherein lower operating costs are associated with lower fuel consumption at high conversion efficiencies, lower battery power usage and lower emissions.
2. The method of claim 1 , further comprising identifying preferred operating conditions for operating the powertrain in a continuously variable mode operating range state to meet an operator torque request.
3. The method of claim 1 , wherein the ranges of permissible transmission inputs comprise a range of permissible transmission input speeds originating from an internal combustion engine.
4. The method of claim 1 , wherein the ranges of permissible inputs to the transmission comprise a range of permissible input torques originating from an internal combustion engine.
5. The method of claim 1 , wherein determining the plurality of motor torques input from the first and second electrical machines to the transmission comprises:
iteratively selecting parametric values within the ranges of permissible inputs to the transmission, and,
determining motor torques for each of the first and second electrical machines based upon the selected parametric values for the inputs to the transmission.
6. The method of claim 5 , wherein each operating cost is determined based upon the selected parametric values for the inputs to the transmission and the determined motor torques input from the first and second electrical machines.
7. The method of claim 6 , wherein each cost is determined based upon engine fuel consumption and electrical battery power cost associated with the transmission input and the motor torques for the first and second electrical machines.
8. Method to identify preferred conditions for operating a powertrain in a continuously variable mode operating range state, comprising:
determining ranges of permissible engine inputs to the transmission;
executing a two-dimensional search engine to iteratively generate parametric values of engine inputs within the ranges of permissible engine inputs to the transmission,
determining motor torques for the first and second electrical machines for each of the iteratively generated parametric values of engine inputs corresponding to an output torque command;
determining operating costs based on inputs comprising motor torques from the first and second electrical machines to the transmission, the iteratively generated parametric values of engine inputs to the transmission and costs related to fuel economy, emissions and battery life, each operating cost associated with one of the determined motor torques for the first and second electrical machines and the associated iteratively generated parametric values of engine inputs to the transmission; and,
identifying preferred engine inputs to the transmission based upon the determined operating costs comprising identifying a preferred input torque and preferred first and second motor torques corresponding to a minimum operating cost.
9. The method of claim 8 , further comprising controlling operation of the engine to achieve the preferred input torque.