| 1. |
- Andersson, Ingemar, 1969, et al.
(författare)
-
Evaluation of a Closed Loop Spark Advance Controller Based on a Torque Sensor
- 2008
-
Ingår i: SAE Technical Papers. - : SAE International. - 0148-7191 .- 2688-3627.
-
Tidskriftsartikel (refereegranskat)abstract
- A closed loop spark advance control system was evaluated on a Volvo V70 5-cylinder spark ignited engine. The system utilises a crankshaft mounted torque sensor for combustion monitoring which provides individual cylinder combustion phasing information and enables individual cylinder spark advance control. The spark advance control system can compensate for changes in combustion operating conditions and hence limit the need for calibration. The spark advance control system was used in a mode of cylinder balancing where the control target is to keep the combustion phasing in all cylinders at a defined setpoint. This control law was evaluated in vehicle tests in an emission test chamber, running pre-defined driving cycles FTP72 and Highway Fuel Economy Test. Analysis shows that the combustion phasing was kept close to the selected setpoint during both tests and, hence, robustness in that sense was demonstrated. The torque ratio concept is used for combustion phasing monitoring based on crankshaft torque measurements. Analysis of the 50% torque ratio as a measure for combustion phasing shows that it is equivalent to 50% burned mass fraction.
|
|
| 2. |
- Andersson, Ingemar, 1969, et al.
(författare)
-
The torque ratio concept for combustion monitoring of internal combustion engines
- 2012
-
Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 20:6, s. 561-568
-
Tidskriftsartikel (refereegranskat)abstract
- This work presents a method to analyze combustion events in an internal combustion engine, called the torque ratio concept. The method is based on crankshafttorque measurements, but an extension to angular speed measurements is possible. The torque ratio concept provides a parametrized model for the combustionprogress from which e.g. combustion phasing can be extracted. The torque ratio concept is derived mathematically and related theoretically to other combustionanalysis methods, such as pressure ratio and net heat release. Finally, analysis on recorded data from a five cylinder spark ignited engine verifies the relationships between the three methods. For combustion phasing, the 50% torque ratio is an equivalent measure to 50% pressure ratio and can be transformed into the 50% net heat release position by using a derived volume ratio function.
|
|
| 3. |
|
|
| 4. |
- Thor, Mikael, 1982, et al.
(författare)
-
Closed-loop diesel engine combustion phasing control based on crankshaft torque measurements
- 2014
-
Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 33, s. 115-124
-
Tidskriftsartikel (refereegranskat)abstract
- Methods for closed-loop combustion phasing control in a diesel engine, based on measurements of crankshaft torque, are developed and evaluated. A model-based method for estimation of cylinder individual torque contributions from the crankshaft torque measurements is explained and a novel approach for identification of crankshaft dynamics is proposed. The use of the combustion net torque concept for combustion phasing estimation in the torque domain is also described. Two different control schemes, one for individual cylinder control and one for average cylinder control, are studied. The proposed methods are experimentally evaluated using a light-duty diesel engine equipped with a crankshaft integrated torque sensor. The results indicate that it is possible to estimate and control on a cylinder individual basis using the measurements from the crankshaft torque sensor. Combustion phasing is estimated with bias levels of less than 0.5 crank angle degrees (CAD) and cycle-to-cycle standard deviations of less than 0.7 CAD for all cylinders and the implemented combustion phasing controllers manage to accurately counteract disturbances in both fuel injection timing and EGR fraction.
|
|
| 5. |
- Thor, Mikael, 1982, et al.
(författare)
-
Estimation of Combustion Phasing Using the Combustion Net Torque Method
- 2011
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902661937 ; 18:PART 1, s. 11827-11832
-
Konferensbidrag (refereegranskat)abstract
- A new and computationally efficient method, called the combustion net torque method, for estimating combustion phasing in an internal combustion engine using crankshaft torque data is presented. The work is motivated by the need of such an estimation method for real-time implementation of a torque based closed-loop combustion phasing control system. The ideal properties of the proposed method, based on torque calculated from cylinder pressure, are studied using simulations and experimental data from both a spark ignited and a compression ignited engine. A relation to 50% burned mass fraction, the most common measure of combustion phasing, is established and the robustness of the method is investigated. The results show that the ideal estimation accuracy of the proposed method is high, especially around the combustion phasing position where maximum engine efficiency is achieved. Also, the computational complexity of the combustion net torque method is significantly lower compared to other existing techniques for torque domain combustion phasing estimation.
|
|
| 6. |
|
|
| 7. |
- Thor, Mikael, 1982, et al.
(författare)
-
Modeling, Identification, and Separation of Crankshaft Dynamics in a Light-Duty Diesel Engine
- 2009
-
Ingår i: SAE Technical Paper Series 2009-01-1798, SAE 2009 International Powertrains, Fuels & Lubricants Meeting, Florence, Italy. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
-
Konferensbidrag (refereegranskat)abstract
- Mathematical models of a torque sensor equipped crankshaft in a light-duty diesel engine are identified, validated, and compared. The models are based on in-cylinder pressure and crankshaft torque data collected from a 5-cylinder common-rail diesel engine running at multiple operating points. The work is motivated by the need of a crankshaft model in a closed-loop combustion control system based on crankshaft torque measurements. In such a system a crankshaft model is used in order to separate the measured crankshaft torque into cylinder individual torque contributions. A method for this is described and used for IMEP estimation. Not surprisingly, the results indicate that higher order models are able to estimate crankshaft torque more accurately than lower order models, even if the differences are small. For IMEP estimation using the cylinder separation method however, these differences have large effects on accuracy. Here, the performance of higher order models is significantly better than for lower order models. Also, models of odd model order perform better than models of even model order. On average, a 9th order model estimates IMEP values to within 2-3% of the reference values.
|
|
| 8. |
- Thor, Mikael, 1982, et al.
(författare)
-
Parameterized Diesel Engine Combustion Modeling for Torque Based Combustion Property Estimation
- 2012
-
Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
-
Tidskriftsartikel (refereegranskat)abstract
- Combustion model structures based on Vibe functions are outlined and investigated in this work. The focus of the study is the use of such model structures for estimation of diesel combustion properties by reconstructing in-cylinder pressure from measurements of crankshaft torque. Investigated combustion properties include the start and phasing of the combustion as well as maximum values of the in-cylinder pressure and its derivative. The accuracy associated with the proposed estimation method is evaluated using ideal torque data, i.e. torque calculated from in-cylinder pressure, that is generated using both simulations and experiments. The results indicate that the uncertainty associated with the estimation of a selected combustion property tends to increase if that property is located close to TDC, where the signal-to-noise ratio is low for a torque signal. The results also show that the ideal torque based estimation of combustion phasing and maximum in-cylinder pressure generally is very accurate while the estimation of start of combustion and the maximum in-cylinder pressure derivative suffers more from disturbances and model imperfections.
|
|
| 9. |
- Thor, Mikael, 1982, et al.
(författare)
-
Parameterized Diesel Engine Heat Release Modeling for Combustion Phasing Analysis
- 2009
-
Ingår i: SAE Technical Paper Series 2009-01-0368, SAE 2009 World Congress, Detroit, MI, USA. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
-
Konferensbidrag (refereegranskat)abstract
- Different Vibe function model structures for parameterized diesel engine heat release models are investigated. The work is motivated by the need of such models when closed-loop combustion control is implemented based on torque domain combustion phasing analysis. Starting from the studied model structures, models are created by estimating the model parameters using a separable least squares approach. After this, the models are evaluated according to two different performance criteria. The first criterion rates the ability of the estimated models to describe reference mass fraction burned traces. The second criterion assesses how accurately the models estimate the reference combustion phasing measure. As expected, the analysis shows that the models based on the most flexible model structure achieve the best results, both regarding mass fraction burned estimation and combustion phasing estimation. However, even if the less complex models describe the mass fraction burned traces with lower accuracy, these models are able to estimate the combustion phasing measure surprisingly well.
|
|
| 10. |
- Thor, Mikael, 1982, et al.
(författare)
-
Using combustion net torque for estimation of combustion properties from measurements of crankshaft torque
- 2014
-
Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 26:1, s. 233-244
-
Tidskriftsartikel (refereegranskat)abstract
- Two methods, both based on the concept of combustion net torque, for estimation of combustion properties using measurements of crankshaft torque data are investigated in this work. The first of the proposed methods estimates entire burned mass fraction traces from corresponding combustion net torque traces. This is done by solving a convex optimization problem that is based on a derived analytical relation between the two quantities. The other proposed estimation method estimates the well established combustion phasing measure referred to as 50% burned mass fraction directly from combustion net torque using a nonlinear black-box mapping. The methods are assessed using both simulations and experimental data gathered from a 5-cylinder light-duty diesel engine equipped with a crankshaft torque sensor and cylinder pressure sensors that are used for reference measurements. The results indicate that both methods work well but the method that estimates entire burned mass fraction traces is more sensitive to torque data quality. Based on the experimental crankshaft torque data, the direct combustion phasing estimation method delivers estimates with a bias of less than 1 CAD and a cycle-to-cycle standard deviation of less than 2.7 CAD for all cylinders.
|
|
