Method And Device For Closed-Loop Control Of The Temperature Of A Component In An Exhaust Tract Of An Internal Combustion Engine By A Predictor

Abstract

The disclosure provides a method and a device for closed-loop control of a temperature of a component in an exhaust-gas tract of an internal combustion engine. The exhaust-gas tract has a temperature sensor arranged upstream of the component. The method includes providing a control circuit for the closed-loop control of the temperature of the component and detecting a measurement signal by the temperature sensor during the operation of the internal combustion engine. The measurement signal is characteristic of an exhaust-gas temperature. The measurement signal is used as a measured controlled variable for the control circuit for the closed-loop control of the temperature of the component. The method also includes determining a temperature model for the exhaust-gas temperature of the exhaust gas upstream of the component. The temperature model is used as a predictor for the control circuit. Also, a modeled controlled variable is provided from the temperature model.

Claims

1. A method for closed-loop control of a temperature of a component in an exhaust-gas tract of an internal combustion engine, the exhaust-gas tract has a temperature sensor arranged upstream of the component in the exhaust-gas tract, the method includes: providing a control circuit for the closed-loop control of the temperature of the component; detecting a measurement signal at the temperature sensor during the operation of the internal combustion engine, the measurement signal is characteristic of an exhaust-gas temperature of an exhaust gas upstream of the component, the measurement signal is used as a measured controlled variable for the control circuit for the closed-loop control of the temperature of the component; providing a temperature model for the exhaust-gas temperature of the exhaust gas, the temperature model is used as a predictor for the control circuit, and the temperature model provides a modeled controlled variable; and setting a manipulated variable of the control circuit for the closed-loop control of the temperature of the component based on the modeled controlled variable and the measured controlled variable.

2. The method of claim 1, wherein the component is a particle filter arranged in the exhaust-gas tract of the internal combustion engine, or wherein the component is an exhaust-gas catalytic converter which is arranged in the exhaust-gas tract of the internal combustion engine.

3. The method of claim 1, wherein the component is an exhaust-gas catalytic converter arranged in the exhaust-gas tract of the internal combustion engine.

4. The method of claim 1, wherein the manipulated variable of the control circuit is a reserve torque of the internal combustion engine which is set by control of an ignition timing of individual cylinders of the internal combustion engine.

5. The method of claim 1, wherein the modeled controlled variable is provided by the temperature model based on at least one operating parameter of the internal combustion engine.

6. The method of claim 5, wherein at least one of the operating parameters is a rotational speed of the internal combustion engine, a load of the internal combustion engine, an ignition angle of the internal combustion engine, a lambda value of the internal combustion engine, an exhaust-gas mass flow rate of the internal combustion engine or a coolant temperature of the internal combustion engine.

7. The method of claim 5, wherein the modeled controlled variable is additionally provided by the temperature model based on at least one environmental parameter.

8. The method of claim 7, wherein at least one of the environmental parameters is an ambient air temperature or an ambient air pressure.

9. The method of claim 1, wherein the temperature model is a dynamic temperature model which dampens disturbance variables on the control circuit by a damping function.

10. The method of claim 1, wherein the temperature model has a temperature model without dead time and has a temperature model with dead time.

11. A device for closed-loop control of a temperature of a component in an exhaust-gas tract of an internal combustion engine, the device comprising: a control unit configured to execute the following: detecting a measurement signal at a temperature sensor during the operation of the internal combustion engine, the temperature sensor arranged upstream of the component in the exhaust-gas tract, the measurement signal is characteristic of an exhaust-gas temperature of an exhaust gas upstream of the component, the measurement signal is used as a measured controlled variable for a control circuit for the closed-loop control of the temperature of the component; providing a temperature model for the exhaust-gas temperature of the exhaust gas, the temperature model is used as a predictor for the control circuit, and the temperature model provides a modeled controlled variable; and setting a manipulated variable of the control circuit for the closed-loop control of the temperature of the component based on the modeled controlled variable and the measured controlled variable.

12. The device of claim 11, wherein the component is a particle filter arranged in the exhaust-gas tract of the internal combustion engine, or wherein the component is an exhaust-gas catalytic converter which is arranged in the exhaust-gas tract of the internal combustion engine.

13. The device of claim 11, wherein the component is an exhaust-gas catalytic converter arranged in the exhaust-gas tract of the internal combustion engine.

14. The device of claim 11, wherein the manipulated variable of the control circuit is a reserve torque of the internal combustion engine which is set by control of an ignition timing of individual cylinders of the internal combustion engine.

15. The device of claim 11, wherein the modeled controlled variable is provided by the temperature model based on at least one operating parameter of the internal combustion engine.

16. The device of claim 15, wherein at least one of the operating parameters is a rotational speed of the internal combustion engine, a load of the internal combustion engine, an ignition angle of the internal combustion engine, a lambda value of the internal combustion engine, an exhaust-gas mass flow rate of the internal combustion engine or a coolant temperature of the internal combustion engine.

17. The device of claim 15, wherein the modeled controlled variable is additionally provided by the temperature model on the basis of at least one environmental parameter.

18. The device of claim 17, wherein at least one of the environmental parameters is an ambient air temperature or an ambient air pressure.

19. The device of claim 11, wherein the temperature model is a dynamic temperature model which dampens disturbance variables on the control circuit by a damping function.

20. The device of claim 11, wherein the temperature model has a temperature model without dead time and has a temperature model with dead time.

Description

DESCRIPTION OF DRAWINGS

[0023] FIG. 1 is a schematic illustration of an internal combustion engine with an exhaust-gas tract and a control unit.

[0024] FIG. 2 shows a block diagram of a method for closed-loop control of a temperature of a component in an exhaust-gas tract of an internal combustion engine.

[0025] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0026] FIG. 1 is a schematic illustration of an internal combustion engine 100 with an exhaust-gas tract 110 which is designed to discharge the exhaust gas 160 from the internal combustion engine 100. The internal combustion engine 100 has an internal combustion engine block 120 and an ignition system 130. The ignition system 130 controls the ignition of the individual fuel-air mixtures in the cylinders of the internal combustion engine block 120. The internal combustion engine 100 additionally has an intake tract 140 which is designed to conduct intake air 150 into the internal combustion engine block 120. The exhaust-gas tract 110 discharges the exhaust gas 160 from the internal combustion engine block 120. According to FIG. 1, the exhaust-gas tract 110 has a particle filter 172 and an exhaust-gas catalytic converter 174. The exhaust-gas catalytic converter is arranged downstream of the internal combustion engine block 120. The particle filter 172 is arranged downstream of the exhaust-gas catalytic converter 174 in the exhaust-gas flow direction. The particle filter 172 and the exhaust-gas catalytic converter 174 are arranged as components 170 in the exhaust-gas tract 110. The exhaust-gas tract 110 additionally has a temperature sensor 180. The temperature sensor 180 is arranged in the exhaust-gas tract 110 upstream of the exhaust-gas catalytic converter 174 and downstream of the internal combustion engine block 120. The temperature sensor 180 is designed to detect a measurement signal 310 (FIG. 2), where the measurement signal 310 is characteristic of an exhaust-gas temperature 312 (FIG. 2) of the exhaust gas 160 of the internal combustion engine 100.

[0027] FIG. 1 also shows a control unit 200 having a processing unit 210, a data memory 220, a program memory 230 and a fault memory 240. The control unit 200 processes the measurement signal 310 from the temperature sensor 180. The control unit 200 is additionally designed to carry out the method according to the present disclosure and thereby perform closed-loop control of the temperature of the component 170 in the exhaust-gas tract 110 of the internal combustion engine 100. In this regard, required parameters may be stored in the data memory 220 of the control unit 200. A temperature model 320 (FIG. 2) may additionally be stored in the program memory 230 of the control unit 200. During the operation of the internal combustion engine 100, the processing unit 210 of the control unit 200 may use the measurement signal 310 from the temperature sensor 180 and use the temperature model 320 to determine a modeled controlled variable 340 (FIG. 2) and a measured controlled variable 330 (FIG. 2) and may provide these to a control circuit, from which controlled variables a manipulated variable 350 (FIG. 2) for the control circuit is determined, where the manipulated variable 350 is fed to the ignition system 130 of the internal combustion engine 100 in order to perform closed-loop control of the temperature of at least one of the components 170 in the exhaust-gas tract 110 of the internal combustion engine 100. Should a fault occur during the closed-loop control of the temperature of at least one of the components 170, this fault may be stored in the fault memory 240 of the control unit 200. In addition, a fault display device 250 may be activated in order to display the fault to a user of the internal combustion engine 100 or to a driver who is driving a vehicle with the internal combustion engine 100.

[0028] FIG. 2 shows a block diagram 300 of an example of a method executed on the control unit 200. According to the block diagram 300, a measurement signal 310 is provided which is characteristic of the exhaust-gas temperature 312. A measured controlled variable 330, which is used for the closed-loop control of the temperature of the component, is provided from the measurement signal 310. In addition, a temperature model 320 is provided. The temperature model 320 has a temperature model 322 without dead time and has a temperature model 324 with dead time. The temperature model 320 may be stored on the program memory 230 of the control unit 200. The temperature model 320 serves as a predictor 326 for the control circuit for the closed-loop control of the temperature of the component 170. Operating parameters 342 of the internal combustion engine 100 and environmental parameters 344 are input into the temperature model 320. By way of the temperature model 320 and the input data (operating parameters 342 and environmental parameters 344), a modeled controlled variable 340 is determined. The modeled controlled variable 340 is used for the closed-loop control of the temperature of the component 170. A manipulated variable 350 for the control circuit is determined from the modeled controlled variable 340 and the measured controlled variable 330. The manipulated variable 350 is transmitted to the ignition system 130 of the internal combustion engine 100, whereby the reserve torque is controlled by the ignition angle, whereby the temperature of the component 170 in the exhaust-gas tract 110 is controlled in closed-loop fashion.

[0029] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.