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Hardware-in-the-Loop Simulation of Diesel Engines for the Development of Engine Control Systems
Copyright © IFAC Algorithms and Architectures for Real-Time Control. Vilamoura. Portugal. 1997
Hardware-In-The-Loop Simulation of Diesel Engines for the Development of Engine Control Systems R. Isermann, S. Sinsel, S. Schaffnit Institute of Automatic Control, Dannstadt University of Technology Landgraf-Georg-Str. 4, D-64283 Darmstadt, Germany Phone: +496151 162112 Fax: +496161 293445
Keywords: Diesel-engine, mode ling, simulation, hardware-in-the-loop
special digital circuit the pulses of the crankshaft and camshaft inductive speed sensors (8 bit / 10 deg cs). The sensor interface also contains relays to simulate faults like interruptions, short cuts, etc. The actuatorinterface consists of the injection valve control. The injection valves are the real components (pump-linenozzle-injection-system). The actuator interface measures the magnetic valve currents to determine the real valve opening time moments and calculates the pulse width and begin of injection for the engine simulator. "Driving" of the simulator can be performed either with a control panel or with a windows-surface of the host PC, by operating the gas, brake, clutch, gear, retarder etc, or automatically by a program.
1. INTRODUCTION With increasing demands on fuel consumption, emissions, static and dynamic behaviour of combustion engines a multitude of functions has to be performed by the engine electronics. Real-time hardware-in-the-loop (HIL) simulators, where parts of the overall system are simulated or are real components become increasingly important development tools. Fig. 1 shows a scheme where the Diesel-engine, the vehicle and some sensors and actuators are simulated and the electronic engine management and some actuators and sensors are real components. This has following advantages for the development of engine control and, in general mechatronic systems: saving of expensive engine dynamometers testing of control, supervision and diagnosis functions save operation in dangerous conditions parallel (concurrent) engineering of the engine, gear, drive chain, and electronic devices
2. SIMULATION TEST BENCH Fig. 2 shows the scheme of the real-time simulator for a truck Diesel-engine. To simulate each cylinder function, a high resoluted torque generation, the coupled turbocharger and the vehicle a transputer system with 11 processors (T805) was developed. 4 transputers are used for the engine simulation and 7 for I/O communication with the simulator periphery and the host-PC. The periphery consists of the sensor and the actuator interface. The sensor interface generate the sensor signals like temperatures, pressures, liquid levels in the form of voltages and with a
IHcmtae l
Fig.1
91
General scheme for the hardware-in-the-loop simulation of a combustion engine with vehicle
WmdowsUser Interface
Control Panel
Ib 0
C
:::AJ
////.o?7 _PodaI. BnkePcda1, a...b,
0..
CAN-
BUS
t
a: .---\
+
Con1roI Unit
Fig.2
Scheme of the real-time simulator with simulated engine, hardware imitation of the sensors and real digital motor management and real injection actuators
3. PROCESS-, SENSOR - AND ACTUATOR MODELS
mass and gas forces and an effective part, describing the gas forces through combustion.
Fig. 3 depicts the three main parts of the process in a two-port representation : the Diesel engine, the turbo charger and the vehicle and drive chain.
"... ---O..---...... -god-,---, 9~
9...
cyll_,torq..
(•.~:=.... aionel map)
f--=--~
Fig. 4 Torque generation for real-time simulation Based on measured and calculated combustion pressure an adaptation of the model is possible. The engine torque is then represented as a discrete angle signal with 0 0 =10 deg sampling angle. The strongly non linear behaviour of the turbocharger was described by dynamic neural nets (dynamic multilayer perceptron) with fuel mass and engine speed as inputs and the charging pressure as output. The vehicle was simulated as a two-mass model (3rd order) which lumps clutch, gear, drive chain, body, wheels and brake. The simulation of the vehicle is performed with variable sampling time Toveh=0JOlen o (synchronous date transfer) and the simulation of the turbocharger with constant sampling time To.turb =lOms (asynchronous data transfer with data buffer). Fig. 5 shows the simulation blockdiagram and some signals.
Fig.3
Two-port representation of the simulated Diesel engine with turbocharger and truck 0 pwi : pulse width of injection [deg. crankshaft] 0 bi : begin of injection [deg. crankshaft]
For realisation of the real-time simulation several compromises had to be made with regard to details of mode ling, parallel computing, parametrization and coupling with the real digital control device. The generation of the crankshaft torque with a resolution of 10 deg. for each cylinder followed the block diagram of Fig. 4 . The averaged static torque is determined by a multidimensional map. The dynamic torques consist of a zero-mean part, describing the
•
92
0
n.,(U/min)
M..,INm)
~~MMM 0.1
1200
0.1
0.2 «5)
0.2 «5)
360
turbocharger
engine
continuous-time model
discrete angle model
discrete-time simulation ::onstant sampling time T .....
Fig.5
asynchronous data transfer
e. eo
vehicle/drive chain continuous-time model
iliscrete angle synchronous synchronous discrete angle synchronous data transfer simulation with continuous simulation time model constant sampling angle variable sampling time T.....{i8.)
eo
Blockdiagram for the discrete angle and discrete time simulation on a multi processor system 4. SIMULATION EXAMPLES
$DO
'000
I[",.J
Fig.6
The real-time simulator was developed for MercedesBenz truck Diesel engines. The following examples are shown for the OM 502 (8 cyl, 420 kW at 1800 rpm). Fig. 6 shows the effect of a cylinder fire failure under idling control. The sampling angle is E>o=IOdeg. A full power acceleration of a 40 tons truck including three gear shifts is demonstrated in Fig. 7. One can observe e.g. the engine speed and torque (for investigating of e.g. different gear shifting strategies), the drive chain oscillations and the relatively inert reaction of the turbo charging pressure.
Real-time simulation of a cylinder failure during idling with idling speed control
REFERENCES Isermann, R et al : Model-Based Control and Supervision of Vehicle Dynamics. Fisita , Prag, 1996. Kessel, J.-A., Isermann, R: Methoden zur modellgestiitzten Steuerung und Regelung von Dieselmotoren mit Turbolader. 16. Int. Wiener Motorensymposium 1995. Nelles, 0., Sinsel, S., Isermann, R : Local Basis Function Networks for Identification of a Turbocharger. lEE UKACC Control '96 Exeter, UK, 1996. Schmidt, c.: Digitale kurbelwinkelsynchrone Modellbildung und Drehschwingungsdampfung eines Dieselmotors mit Last. Fortschr.Ber. VDI Reihe 12 Nr. 253, VDI-Verlag, Diisseldorf, 1995. Sinsel, S., Schaffnit, J, Isermann, R : Hardware-inthe-Loop Simulation von Dieselmotoren fur die Entwicklung modemer Motormanagementsysteme. VDI-Tagung, Moers, Germany, 1997.
«Xl
E
-;,"'" E
..
°o~~~----,~ c ----~----~~~
-101
Fig.7
Acknowledgement: The authors appreciate the good cooperation with Mercedes Benz AG, Stuttgart.
Full power acceleration of a 40 tons truck
93
Hardware-In-The-Loop Simulation of Diesel Engines for the Development of Engine Control Systems R. Isermann, S. Sinsel, S. Schaffnit Institute of Automatic Control, Dannstadt University of Technology Landgraf-Georg-Str. 4, D-64283 Darmstadt, Germany Phone: +496151 162112 Fax: +496161 293445
Keywords: Diesel-engine, mode ling, simulation, hardware-in-the-loop
special digital circuit the pulses of the crankshaft and camshaft inductive speed sensors (8 bit / 10 deg cs). The sensor interface also contains relays to simulate faults like interruptions, short cuts, etc. The actuatorinterface consists of the injection valve control. The injection valves are the real components (pump-linenozzle-injection-system). The actuator interface measures the magnetic valve currents to determine the real valve opening time moments and calculates the pulse width and begin of injection for the engine simulator. "Driving" of the simulator can be performed either with a control panel or with a windows-surface of the host PC, by operating the gas, brake, clutch, gear, retarder etc, or automatically by a program.
1. INTRODUCTION With increasing demands on fuel consumption, emissions, static and dynamic behaviour of combustion engines a multitude of functions has to be performed by the engine electronics. Real-time hardware-in-the-loop (HIL) simulators, where parts of the overall system are simulated or are real components become increasingly important development tools. Fig. 1 shows a scheme where the Diesel-engine, the vehicle and some sensors and actuators are simulated and the electronic engine management and some actuators and sensors are real components. This has following advantages for the development of engine control and, in general mechatronic systems: saving of expensive engine dynamometers testing of control, supervision and diagnosis functions save operation in dangerous conditions parallel (concurrent) engineering of the engine, gear, drive chain, and electronic devices
2. SIMULATION TEST BENCH Fig. 2 shows the scheme of the real-time simulator for a truck Diesel-engine. To simulate each cylinder function, a high resoluted torque generation, the coupled turbocharger and the vehicle a transputer system with 11 processors (T805) was developed. 4 transputers are used for the engine simulation and 7 for I/O communication with the simulator periphery and the host-PC. The periphery consists of the sensor and the actuator interface. The sensor interface generate the sensor signals like temperatures, pressures, liquid levels in the form of voltages and with a
IHcmtae l
Fig.1
91
General scheme for the hardware-in-the-loop simulation of a combustion engine with vehicle
WmdowsUser Interface
Control Panel
Ib 0
C
:::AJ
////.o?7 _PodaI. BnkePcda1, a...b,
0..
CAN-
BUS
t
a: .---\
+
Con1roI Unit
Fig.2
Scheme of the real-time simulator with simulated engine, hardware imitation of the sensors and real digital motor management and real injection actuators
3. PROCESS-, SENSOR - AND ACTUATOR MODELS
mass and gas forces and an effective part, describing the gas forces through combustion.
Fig. 3 depicts the three main parts of the process in a two-port representation : the Diesel engine, the turbo charger and the vehicle and drive chain.
"... ---O..---...... -god-,---, 9~
9...
cyll_,torq..
(•.~:=.... aionel map)
f--=--~
Fig. 4 Torque generation for real-time simulation Based on measured and calculated combustion pressure an adaptation of the model is possible. The engine torque is then represented as a discrete angle signal with 0 0 =10 deg sampling angle. The strongly non linear behaviour of the turbocharger was described by dynamic neural nets (dynamic multilayer perceptron) with fuel mass and engine speed as inputs and the charging pressure as output. The vehicle was simulated as a two-mass model (3rd order) which lumps clutch, gear, drive chain, body, wheels and brake. The simulation of the vehicle is performed with variable sampling time Toveh=0JOlen o (synchronous date transfer) and the simulation of the turbocharger with constant sampling time To.turb =lOms (asynchronous data transfer with data buffer). Fig. 5 shows the simulation blockdiagram and some signals.
Fig.3
Two-port representation of the simulated Diesel engine with turbocharger and truck 0 pwi : pulse width of injection [deg. crankshaft] 0 bi : begin of injection [deg. crankshaft]
For realisation of the real-time simulation several compromises had to be made with regard to details of mode ling, parallel computing, parametrization and coupling with the real digital control device. The generation of the crankshaft torque with a resolution of 10 deg. for each cylinder followed the block diagram of Fig. 4 . The averaged static torque is determined by a multidimensional map. The dynamic torques consist of a zero-mean part, describing the
•
92
0
n.,(U/min)
M..,INm)
~~MMM 0.1
1200
0.1
0.2 «5)
0.2 «5)
360
turbocharger
engine
continuous-time model
discrete angle model
discrete-time simulation ::onstant sampling time T .....
Fig.5
asynchronous data transfer
e. eo
vehicle/drive chain continuous-time model
iliscrete angle synchronous synchronous discrete angle synchronous data transfer simulation with continuous simulation time model constant sampling angle variable sampling time T.....{i8.)
eo
Blockdiagram for the discrete angle and discrete time simulation on a multi processor system 4. SIMULATION EXAMPLES
$DO
'000
I[",.J
Fig.6
The real-time simulator was developed for MercedesBenz truck Diesel engines. The following examples are shown for the OM 502 (8 cyl, 420 kW at 1800 rpm). Fig. 6 shows the effect of a cylinder fire failure under idling control. The sampling angle is E>o=IOdeg. A full power acceleration of a 40 tons truck including three gear shifts is demonstrated in Fig. 7. One can observe e.g. the engine speed and torque (for investigating of e.g. different gear shifting strategies), the drive chain oscillations and the relatively inert reaction of the turbo charging pressure.
Real-time simulation of a cylinder failure during idling with idling speed control
REFERENCES Isermann, R et al : Model-Based Control and Supervision of Vehicle Dynamics. Fisita , Prag, 1996. Kessel, J.-A., Isermann, R: Methoden zur modellgestiitzten Steuerung und Regelung von Dieselmotoren mit Turbolader. 16. Int. Wiener Motorensymposium 1995. Nelles, 0., Sinsel, S., Isermann, R : Local Basis Function Networks for Identification of a Turbocharger. lEE UKACC Control '96 Exeter, UK, 1996. Schmidt, c.: Digitale kurbelwinkelsynchrone Modellbildung und Drehschwingungsdampfung eines Dieselmotors mit Last. Fortschr.Ber. VDI Reihe 12 Nr. 253, VDI-Verlag, Diisseldorf, 1995. Sinsel, S., Schaffnit, J, Isermann, R : Hardware-inthe-Loop Simulation von Dieselmotoren fur die Entwicklung modemer Motormanagementsysteme. VDI-Tagung, Moers, Germany, 1997.
«Xl
E
-;,"'" E
..
°o~~~----,~ c ----~----~~~
-101
Fig.7
Acknowledgement: The authors appreciate the good cooperation with Mercedes Benz AG, Stuttgart.
Full power acceleration of a 40 tons truck
93