Method and apparatus for soft costing input speed and output speed in mode and fixed gear as function of system temperatures for cold and hot operation for a hybrid powertrain system
View Patent ↗Methods and systems for manipulating inputs relating to transmission shifting events in a hybrid-engine powered vehicle equipped with an electro-mechanical hybrid transmission include sets of preferability factors inputted from engine sensors are combined in a microprocessor or computer with other preferability factors generated during engine and vehicle operation to provide an output for a transmission control module, which may execute an operating range or engine state change. Desirable input speeds for a transmission are determined by defining minimum input speeds for each potential transmission operating range state, and ascribing biasing costs to potential transmission input speeds which are slower than the minimum input speeds defined for each potential transmission operating range state. A single transmission input speed is selected and preferability factors are determined, which are preferentially weighted to enable selective commandment of changes in the transmission operating range state and engine state.
1. Method for controlling a powertrain system including an engine coupled to an electro-mechanical transmission selectively operative in one of a plurality of transmission operating range states and one of a plurality of engine states, comprising:
determining a current transmission operating range state and engine state;
determining at least one potential transmission operating range state and engine state;
optionally providing an operator torque request;
defining a minimum value for an input speed to said transmission for each potential transmission operating range state, said defining including comparison of a first potential minimum input speed to said transmission that is a function of a desired output speed of said transmission, and a second potential minimum input speed to said transmission that is a function of at least one other operational parameter of said powertrain system;
providing a plurality of proposed values for the input speed to said transmission for each potential transmission operating range state, each of said proposed values for the input speed also having associated with it a power input for said transmission, and a power loss;
ascribing a biasing cost to each of those proposed values for the transmission input speeds which are lower than said minimum value defined for each potential transmission operating range state, wherein said biasing cost ascribed to each of those proposed values has a magnitude which is proportional to the difference between its rpm and the rpm of said minimum value for each potential transmission operating range state;
selecting a single transmission input speed from said plurality of proposed values for each potential transmission operating range state;
determining preferability factors associated with the current transmission operating range state and engine state, and potential transmission operating range states and engine states;
preferentially weighting the preferability factors for the current transmission operating range state and engine state; and
selectively commanding changing the transmission operating range state and engine state based upon said preferability factors and said single transmission input speed.
2. A method according to claim 1 wherein the transmission operating range states for which minimum values for the input speed to said transmission is defined are transmission pre-select ranges.
3. A method according to claim 1 wherein a mathematical function is used for ascribing a biasing cost to each of those proposed values for the transmission input speeds which are lower than said minimum value.
4. A method according to claim 3 wherein said function comprises a function selected from the group consisting of: linear functions, non-linear functions, and functions which comprise both linear and non-linear features.
5. A method according to claim 1 wherein said minimum values for the input speed to said transmission for each of the potential pre-select range states are defined as a function of transmission output speed.
6. A method according to claim 1 further comprising selection of one of said first potential minimum input speed to said transmission that is a function of the desired output speed of said transmission, and a second potential minimum input speed to said transmission that is a function of at least one other operational parameter of said powertrain system.
7. A method according to claim 6 wherein said selection comprises choosing the minimum speed having the highest rpm value from said first potential minimum speed and said second potential minimum speed.