Adaptive Estimation of the Engine Friction Torque

Author(s):  
A. Stotsky
Author(s):  
A A Stotsky

Errors in the estimation of friction torque in modern spark ignition automotive engines necessitate the development of real-time algorithms for adaptation of the friction torque. Friction torque in the engine control unit is presented as a look-up table with two input variables (the engine speed and indicated engine torque). The algorithms proposed in this paper estimate the engine friction torque via the crankshaft speed fluctuations at the fuel cut-off state and at idle. A computationally efficient filtering algorithm for reconstruction of the first harmonic of a periodic signal is used to recover an amplitude which corresponds to engine events from the noise-contaminated engine speed measurements at the fuel cut-off state. The values of the friction torque at the nodes of the look-up table are updated, when new measured data of the friction torque are available. New data-driven algorithms which are based on a stepwise regression method are developed for adaptation of look-up tables. The algorithms are verified by using a spark ignition six-cylinder prototype engine.


Author(s):  
Rassem R. Henry

This paper describes an engine-starting simulation that uses models of the electrical, engine dynamics and engine thermodynamics subsystems combining them with engine friction models. One of these friction models uses the physical parameters of the engine as basis for estimating the friction torque. This allows engine performance prediction, hence the ability to size the electrical starting system, without engine availability. The resultant simulation is developed using SIMULINK/MATLAB™ and it has been validated for two engines; the first is a 4-cylinder engine with a conventional valve train, and relatively high friction by today’s standards, and the second is a more recent 3-cylinder engine with lowfriction. Validation of the first engine was done based on matching its published starting tests with results obtained using this paper’s simulation. The validation of the second engine was carried out by comparing engine test results with simulation results. Tests in the first case were for engine starting including firing and in the second case were for cranking only conditions.


Measurement ◽  
2021 ◽  
Vol 174 ◽  
pp. 109035
Author(s):  
Xuxing Zhao ◽  
Renjian Feng ◽  
Yinfeng Wu ◽  
Ning Yu ◽  
Xiaofeng Meng ◽  
...  

Inventions ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 10
Author(s):  
Sergey Sokolov ◽  
Arthur Novikov ◽  
Marianna Polyakova

In measurement systems operating under various disturbances the probabilistic characteristics of measurement noises are usually known approximately. To improve the observation accuracy, a new approach to the Kalman’s filter adaptation is proposed. In this approach, the Covariance Matrix of Measurement Noises (CMMN) is estimated by accurate measurements detected irregularly by the mobile object observation system (from radiofrequency identifiers, etalon reference, fixed points etc.). The problem of adaptive estimation of the observer’s noises covariance matrix in the Kalman filter is solved analytically for two cases: mutual noises correlation, and its absence. The numerical example for adaptive filtration of complexing navigation system parameters of a mobile object using irregular accurate measurements is given to illustrate the effectiveness of the proposed algorithm. Coordinate estimating errors have changed in comparison with the traditional scheme from 100 m to 2 m in latitude, and from 200 m to 1.5 m in longitude.


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