Analysis of the Interactions Between Indicated and Reciprocating Torques for the Development of a Torsional Behavior Model of the Powertrain

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Fabrizio Ponti ◽  
Luca Solieri
Keyword(s):  
Engine Speed ◽  
Wave Form ◽  
Behavior Model ◽  
Identification Process ◽  
Speed Measurement ◽  
Torque Estimation ◽  
Torsional Behavior ◽  
Set Up ◽  
Correct Estimation ◽  
Speed Fluctuations

Torque-based engine control systems usually employ a produced torque estimation feedback in order to verify that the strategy target torque has been met. Torque estimation can be performed using static maps describing the engine behavior or using models describing the existing relationships between signals measured on the engine and the indicated torque produced. Signals containing information on the combustion development, suitable for this purpose, are, among others, the ion-current signal, the vibration signals obtained from accelerometers mounted on the engine block, or the instantaneous engine speed fluctuations. This paper presents the development and the identification process of an engine-driveline torsional behavior model that enables indicated torque estimation from instantaneous engine speed measurement. Particular attention has been devoted to the interactions between indicated and reciprocating torques, and their effects over instantaneous engine speed fluctuations. Indicated and reciprocating torques produce, in fact, opposite excitations on the driveline that show opposite effects on the engine speed wave form: For low engine speed, usually indicated torque prevails, while the opposite applies for higher engine speed. In order to correctly estimate indicated torque from engine speed measurement, it is therefore necessary to correctly evaluate the reciprocating torque contribution. Reciprocating torque is usually described using a wave form as a function of crank angle, while its amplitude depends on the value of the reciprocating masses. As mentioned before, knowledge of the reciprocating masses is fundamental in order to obtain correct estimation of the indicated torque. The identification process that has been set up for the engine-driveline torsional model enables to evaluate the relationship between torques applied to the engine and the corresponding engine speed wave form even without knowing the value of the reciprocating masses. In addition, once this model has been set up, it is possible to estimate with high precision the value of the reciprocating masses. Particular attention has also been devoted to the feasibility of the application of the identified model onboard for torque estimation; for this reason, the model has been developed in a very simple form. The approach proved to be effective both on gasoline and diesel engines, both for engine mounted on a test cell and onboard, with different engine configurations. Examples of application are given for some of the configurations investigated.

Analysis of the Interactions Between Indicated and Reciprocating Torques for the Development of a Torsional Behavior Model of the Powertrain

2007 ◽  
Author(s):  
Fabrizio Ponti ◽  
Luca Solieri
Keyword(s):  
Engine Speed ◽  
Behavior Model ◽  
Identification Process ◽  
Speed Measurement ◽  
Torque Estimation ◽  
Crank Angle ◽  
Torsional Behavior ◽  
Correct Estimation ◽  
Speed Fluctuations ◽  
The Relationship

Torque-based engine control systems usually employ a produced torque estimation feedback in order to verify that the strategy target torque has been met. Torque estimation can be performed using static maps describing the engine behaviour or using models describing the existing relationships between signals measured on the engine and the indicated torque produced. Signals containing information on the combustion development, suitable for this purpose, are, among other, the ion-current signal, the vibration signals obtained from accelerometers mounted on the engine block, or the instantaneous engine speed fluctuations. This paper presents the development and the identification process of an engine-driveline torsional behavior model that enables indicated torque estimation from instantaneous engine speed measurement. Particular attention has been devoted to the interactions between indicated and reciprocating torques, and their effects over instantaneous engine speed fluctuations. Indicated and reciprocating torques produce, in fact, opposite excitations on the driveline that show opposite effects on the engine speed waveform: for low engine speed usually indicated torque prevails, while the opposite applies for higher engine speed. In order to correctly estimate indicated torque from engine speed measurement it is therefore necessary to correctly evaluate the reciprocating torque contribution. Reciprocating torque is usually described using a waveform as a function of crank angle, while its amplitude depends on the value of the reciprocating masses. As mentioned before, knowledge of the reciprocating masses is fundamental in order to obtain correct estimation of the indicated torque. The identification process that has been setup for the engine-driveline torsional model enables to evaluate the relationship between torques applied to the engine and the corresponding engine speed waveform even without knowing the value of the reciprocating masses. In addition, once this model has been setup, it is possible to estimate with high precision the value of the reciprocating masses. Particular attention has been devoted also to the feasibility of the application of the identified model on-board for torque estimation; for this reason the model has been developed in a very simple form. The approach proved to be effective both on gasoline and diesel engine, both for engine mounted on a test cell and on-board, with different engine configurations. Examples of application are given for some of the configurations investigated.

On-Board Indicated Pressure and Torque Estimation in Engines With a High Number of Cylinders

2002 ◽  
Author(s):  
Enrico Corti ◽  
Davide Moro
Keyword(s):  
Control Strategy ◽  
Engine Speed ◽  
Fuel Injection ◽  
Control Strategies ◽  
Engine Control ◽  
Cylinder Pressure ◽  
Signal Processing Algorithm ◽  
Operating Condition ◽  
Torque Estimation ◽  
Speed Fluctuations

In recent years engine control development focused the attention on torque-based models, that allow improving driveability and implementing traction control strategies. The design of such a torque-based engine control strategy requires the knowledge of the torque produce by the engine, which depends on fuel injection time, spark advance, throttle opening, EGR command, … In the actual engine control strategies this is mainly done by means of static maps stored in the ECU memory. The real engine torque production under every operating condition can be evaluated by means of the in-cylinder pressure estimation, thus allowing a torque based closed loop control strategy. Many approaches are present in the literature showing the possibility of on-board estimating the actual torque produced by the engine not simply by using static maps, but estimating it through other measured signals. Most of the methodologies that do not require a specific sensor placed on the engine are based either on the engine speed fluctuations (measured by a pick-up facing the flywheel teeth) or on the engine block vibrations (measured by the knock sensor), performing better for engines with a low number of cylinders. The paper presents an original methodology based on the instantaneous engine speed fluctuations, that has been usefully applied to engines with higher number of cylinders. The methodology is based on the observation of the speed fluctuations in a crankshaft window inside the expansion stroke and on the hypothesis that there exists a strong correlation between these engine speed fluctuations and pressure inside the selected cylinder. This relationship has been characterized using Frequency Response Functions (FRF) for each steady-state engine operating condition. In the following the FRFs have been used to perform in-cylinder pressure and then indicated torque estimation under every operating condition, and a specific signal processing algorithm has been developed in order to apply the procedure during speed and load engine transients. The experimental tests have been conducted mounting a six-cylinder turbo-charged spark-ignited engine in a test cell. The application on-board a vehicle of the same methodology seems to be feasible due to the quickness of the algorithm employed and the presence on-board of all the sensors required for the implementation.

Vibration isolation with clutch disk pre-damper mechanism for the idle rattle phenomenon

2016 ◽  
Vol 24 (8) ◽  
pp. 1518-1534 ◽  
Author(s):  
Alişan Yüceşan ◽  
Semih Sezer
Keyword(s):  
Engine Speed ◽  
Vibration Isolation ◽  
Test Bench ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Speed Measurement ◽  
Proposed Model ◽  
Speed Fluctuations ◽  
Gear Mesh Stiffness

In this paper, the influence of clutch disk pre-damper mechanism constituents on the idle rattle phenomenon was investigated with an analytical model containing a new time-varying gear mesh stiffness function. Comparing experimental results to simulation results for the same excitation input was the key implementation for the validation of proposed model. The engine speed fluctuations represented in the simulation was imported from a speed measurement of a diesel engine in the test bench.

Analysis of the Relationship Between Mean Indicated Torque and Its Waveform for Modern Common Rail Diesel and Gasoline Engines

2008 ◽  
Author(s):  
Fabrizio Ponti ◽  
Matteo Rinaldi
Keyword(s):  
Engine Speed ◽  
Gasoline Engine ◽  
Management Strategies ◽  
System Model ◽  
Gasoline Engines ◽  
Torque Estimation ◽  
Speed Fluctuation ◽  
Harmonic Components ◽  
Speed Fluctuations ◽  
The Relationship

The paper presents the progresses made for the development of a methodology useful for torque estimation, necessary in modern management strategies in order to obtain an indication of the torque produced by the engine. The model developed allows estimating mean indicated torque, cylinder by cylinder, based on instantaneous engine speed fluctuations. The speed signal is picked up directly from the sensor facing the toothed wheel mounted on the engine for control purposes. The engine speed fluctuation amplitudes depend in fact on the combustion and the amount of torque that is being delivered by each cylinder. It is easy to understand therefore how these two quantities, engine speed fluctuation amplitudes and torque production, are strictly connected. The presented methodology is based on two main steps. The first step relies on the identification of the dynamic system model that allows to get torque harmonic from the corresponding engine speed components. The identification could be done by two methods, the first one requiring the knowledge of the value of the reciprocating masses with high precision, and the other one making use of different tests at the same speed but with different loads, in order to estimate separately both the reciprocating masses and the system model. The second step, which constitutes the main focus of this paper, relies on the identification of the relationship between the mean indicated torque and its harmonics. The study of this relationship has been carried out in particular in this paper for a multijet diesel engine and for a gasoline engine. Many tests were performed on different driveline configuration, both in a test-cell, and on-board. Once indicated torque and its harmonic components have been evaluated from in-cylinder pressure signals, identification of the relationship has been possible. Influence of the type of combustion performed has been discussed, as also the effects related to cylinder filling and injection timings.

The Diagnosis of Cylinder Power Faults in Diesel Engines by Flywheel Speed Measurement

1986 ◽  
Vol 200 (1) ◽  
pp. 37-43 ◽  
Author(s):  
J W Freestone ◽  
E G Jenkins
Keyword(s):  
Engine Speed ◽  
Time History ◽  
Operating Conditions ◽  
Magnetic Sensors ◽  
Simplified Model ◽  
Speed Measurement ◽  
Diagnostic Capability ◽  
Speed Fluctuations ◽  
Cylinder Power ◽  
Engine Cycle

A technique for estimating the power contribution of each cylinder in a multi-cylinder diesel engine is developed as an engine diagnostic capability. Robust magnetic sensors are used to obtain a waveform of engine speed fluctuations over one engine cycle under steady state operating conditions. Adopting a simplified model of engine dynamics, a computer processes the time history by application of the discrete Fourier transform to reproduce the crankshaft torque waveform. Subtracting the engine inertia torque provides an estimate of the gas pressure torque waveform, from which the power contribution of individual cylinders can be determined.

Development of a Torsional Behavior Powertrain Model for Multiple Misfire Detection

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Fabrizio Ponti
Keyword(s):  
Torsional Vibration ◽  
Engine Speed ◽  
Detection Algorithm ◽  
Operating Conditions ◽  
Wave Form ◽  
False Alarms ◽  
Time Interval ◽  
Short Time Interval ◽  
Torsional Behavior ◽  
Misfire Detection

Many methodologies have been developed in the past for misfire detection purposes based on the analysis of the instantaneous engine speed. The missing combustion is usually detected, thanks to the sudden engine speed decrease that takes place after a misfire event. Misfire detection and, in particular, cylinder isolation are nevertheless still a challenging issue for engines with a high number of cylinders, for engine operating conditions at low load or high engine speed, and for multiple misfire events. When a misfire event takes place, a torsional vibration is excited and shows up in the instantaneous engine speed wave form. If a multiple misfire occurs, this torsional vibration is excited more than once in a very short time interval. The interaction between these successive vibrations can generate false alarms or misdetection, and an increased complexity when dealing with cylinder isolation. This paper presents the development of a powertrain torsional behavior model in order to identify the effects of a misfire event on the instantaneous engine speed signal. The identified wave form has then been used to filter out the torsional vibration effects in order to enlighten the missing combustions even in the case of multiple misfire events. The model response is also used to speed up the setup process for the detection algorithm employed, thus evaluating, before running specific experimental tests on a test bench facility, the values for the threshold and the optimal setup of the procedure. The proposed algorithm is developed in this paper for an SI L4 engine; its application to other engine configurations is possible, as is also discussed in this paper.

Analytical and Numerical Dynamic Analysis of Gears in the Presence of Engine Acyclism

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
G. Sika ◽  
Ph. Velex
Keyword(s):  
Dynamic Analysis ◽  
Engine Speed ◽  
Degree Of Freedom ◽  
Time Varying ◽  
Numerical Techniques ◽  
Mesh Stiffness ◽  
Response Characteristics ◽  
Set Up ◽  
Speed Fluctuations

A one-degree-of-freedom model of geared transmissions is set up. It incorporates the influence of unsteady rotations due to engine speed fluctuations along with simplified time-varying mesh stiffness functions, including contact losses between the teeth and back strikes. The dynamic tooth loads are determined by several analytical and numerical techniques whose results agree well. Finally, some of the response characteristics due to speed fluctuations are presented and commented upon.

scholarly journals A Control-Oriented Engine Torque Online Estimation Approach for Gasoline Engines Based on In-Cycle Crankshaft Speed Dynamics

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4683
Author(s):  
Qiang Tong ◽  
Hui Xie ◽  
Kang Song ◽  
Dong Zou
Keyword(s):  
Real Time ◽  
Engine Speed ◽  
Estimation Error ◽  
Control Unit ◽  
Friction Torque ◽  
Adaptive Observer ◽  
Load Torque ◽  
Engine Torque ◽  
Brake Torque ◽  
Torque Estimation

Engine brake torque is a key feedback variable for the optimal torque split control of an engine–motor hybrid powertrain system. Due to the limitations in available sensors, however, engine torque is difficult to measure directly. For torque estimation, the unknown external load torque and the overlap of the expansion stroke between cylinders introduce a great disturbance to engine speed dynamics. This makes the conventional cycle average engine speed-based estimation approach unusable. In this article, an in-cycle crankshaft speed-based indicated torque estimation approach is proposed for a four-cylinder engine. First, a unique crankshaft angle window is selected for load torque estimation without the influence of combustion torque. Then, an in-cycle angle-domain crankshaft speed dynamic model is developed for engine indicated torque estimation. To account for the effects of model inaccuracy and unknown external disturbances, a “total disturbance” term is introduced. The total disturbance is then estimated by an adaptive observer using the engine’s historical operating data. Finally, a real-time correction method for the friction torque is proposed in the fuel cut-off scenario. Combining the aforementioned torque estimators, the brake torque can be obtained. The proposed algorithm is implemented in an in-house developed multi-core engine control unit (ECU). Experimental validation results on an engine test bench show that the algorithm’s execution time is about 3.2 ms, and the estimation error of the brake torque is within 5%. Therefore, the proposed method is a promising way to accurately estimate engine torque in real-time.

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