Computationally efficient data-driven algorithms for engine friction torque estimation
First Claim
1. A method for estimating friction torque for an internal combustion engine in a powertrain of an automotive vehicle, the engine having an idle state, a fueled power-on state and a fuel cut-off state, the engine having a crankshaft, engine crankshaft speed being higher during operation in a fuel cut-off state than in an idle state, the powertrain including an engine control unit with memory registers in which a friction torque look-up table resides, the look-up table having input variables comprising engine speed and indicated engine torque, the method comprising the steps of:
- measuring engine crankshaft speed and indicated engine torque when the engine operation in the fuel cut-off state;
measuring engine crankshaft speed fluctuations in the engine fuel cut-off state;
reconstructing a first harmonic of a periodic signal to recover an amplitude that corresponds to engine friction losses using engine crankshaft speed measurements during operation of the engine in a fuel cut-off state; and
updating the engine friction look-up table when new measurements of the engine friction torque obtained from an amplitude signal in the fuel cut-off state are available.
3 Assignments
0 Petitions
Accused Products
Abstract
New algorithms for real-time estimation of the engine friction torque are developed. Engine friction torque can be estimated in a fuel cut-off state and at engine idle. New recursive and computationally efficient data-driven algorithms are developed for adaptation of the look-up tables. The algorithms make it possible to avoid driveability problems that could result from errors in estimating engine friction torque.
33 Citations
16 Claims
-
1. A method for estimating friction torque for an internal combustion engine in a powertrain of an automotive vehicle, the engine having an idle state, a fueled power-on state and a fuel cut-off state, the engine having a crankshaft, engine crankshaft speed being higher during operation in a fuel cut-off state than in an idle state, the powertrain including an engine control unit with memory registers in which a friction torque look-up table resides, the look-up table having input variables comprising engine speed and indicated engine torque, the method comprising the steps of:
-
measuring engine crankshaft speed and indicated engine torque when the engine operation in the fuel cut-off state; measuring engine crankshaft speed fluctuations in the engine fuel cut-off state; reconstructing a first harmonic of a periodic signal to recover an amplitude that corresponds to engine friction losses using engine crankshaft speed measurements during operation of the engine in a fuel cut-off state; and updating the engine friction look-up table when new measurements of the engine friction torque obtained from an amplitude signal in the fuel cut-off state are available. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for estimating friction torque for an internal combustion engine in a powertrain of an automotive vehicle, the engine having an idle state, a fueled power-on state and a fuel cut-off state, the powertrain including an engine control unit with memory registers in which a friction torque look-up table resides, the look-up table having input variables comprising engine speed and indicated engine torque, the method comprising the steps of:
-
measuring engine crankshaft speed and determining indicated engine torque; reconstructing a first harmonic of a periodic signal to recover an amplitude that corresponds to engine friction losses using current engine crankshaft speed measurements during operation of the engine in a fuel cut-off state; comparing newly estimated engine friction torque with engine friction torque in memory registers at a certain crankshaft speed and indicated torque; and adapting the look-up table of the engine friction torque by changing the position and orientation of a mathematical three-dimensional frictional surface as a function of engine speed and indicated torque compensating changes in engine operating conditions. - View Dependent Claims (9, 10)
-
-
11. A method for estimating friction torque for an internal combustion engine in a powertrain of an automotive vehicle, the engine having an idle state, a fueled power-on state and a fuel cut-off state, the powertrain including an engine control unit with memory registers in which a friction torque look-up table resides, a compensation term for the friction torque look-up table being presented in the form of a polynomial having coefficients that determine the position and the orientation of a mathematical three-dimensional friction surface and having input variables comprising engine speed and indicated engine torque, the method comprising the steps of:
-
measuring engine crankshaft speed and determining indicated torque during operation of the engine in the fuel cut-off state; and adapting the look-up table friction torque for variations in the input variables whereby friction torque can be predicted for a wide range of speed and indicated torque values. - View Dependent Claims (12, 13, 14, 15, 16)
-
Specification