METHOD AND CONTROL DEVICE FOR DETECTING A COMBUSTION PROCESS OF AN INTERNAL COMBUSTION ENGINE OF A HYBRID VEHICLE

• US 20170217427A1
• Filed: 04/20/2017
• Published: 08/03/2017
• Est. Priority Date: 10/21/2014
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Wei, Norbert, Piasecki, Christian, Freiwald, Grit, Trebesius, Samuel, Thauer, Florian
• Granted Patent: US 10,640,107 B2
• Time in Patent Office: Days
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0685 Engine crank angle
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: F02D 2041/228 Warning displays
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor

Abstract

A method for detecting a combustion process of an internal combustion engine of a hybrid vehicle includes the steps of acquiring a rotational speed signal representing a rotational speed of the crankshaft, acquiring a crankshaft angle signal representing a crankshaft angle of the crankshaft, and determining, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in the internal combustion engine. A control device for detecting a combustion process of an internal combustion engine of a hybrid vehicle is also provided.

Claims

1. A method for detecting a combustion process of an internal combustion engine of a hybrid vehicle wherein the internal combustion engine includes a crankshaft, the method comprising:

acquiring a rotational speed signal representing a rotational speed of the crankshaft;

acquiring a crankshaft angle signal representing a crankshaft angle of the crankshaft; and

determining, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in the internal combustion engine, wherein the step of determining includes detecting a rotational speed curve shape based on the rotational speed signal, wherein the rotational speed curve shape includes a dead center rotational speed and a rotational speed maximum, wherein the dead center rotational speed is reached when a cylinder piston of the internal combustion engine is at a top dead center in a power stroke, and wherein the step of determining further includes ascertaining a maximum increase of the rotational speed, starting from the dead center rotational speed up to the rotational speed maximum, wherein the step of determining further includes ascertaining a reference rotational speed, at which a given percentage of the maximum increase is reached, and ascertaining a reference crankshaft angle associated with the reference rotational speed, wherein the step of determining whether a combustion occurs is based on a threshold angle and includes comparing the reference crankshaft angle to the threshold angle and detecting that a combustion occurs when the reference crankshaft angle exceeds the threshold angle.

2. The method according to claim 1, wherein the step of determining includes ascertaining one of a rotational speed and a rotational speed range and ascertaining one of a crankshaft angle and a crankshaft angle range based on one of the rotational speed and the rotational speed range.

3. The method according to claim 1, wherein the step of determining includes ascertaining one of a crankshaft angle and a crankshaft angle range and ascertaining one of a rotational speed and a rotational speed range based on one of the crankshaft angle and the crankshaft angle range.

4. The method according to claim 1, wherein the step of determining includes detecting, based on the rotational speed signal, at least one rotational speed characteristic selected from the group consisting of a rotational speed minimum, a rotational speed maximum, a rotational speed inflection point and a rotational speed value range.

5. The method according to claim 1, which comprises detecting that no combustion occurs when the reference crankshaft angle is smaller than the threshold angle.

6. The method according to claim 5, which comprises notifying a driver of the hybrid vehicle.

7. The method according to claim 5, which comprises uncoupling the internal combustion engine.

8. The method according to claim 5, which comprises continue moving the hybrid vehicle with an additional drive device as an independent drive.

9. The method according to claim 1, wherein the given percentage is any percentage between 20% and 40% of the maximum increase.

10. A data memory containing a computer program with instructions for executing a method of:

acquiring a rotational speed signal representing a rotational speed of a crankshaft of an internal combustion engine of a hybrid vehicle;

acquiring a crankshaft angle signal representing a crankshaft angle of the crankshaft; and

determining, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in the internal combustion engine, wherein the step of determining includes detecting a rotational speed curve shape based on the rotational speed signal, wherein the rotational speed curve shape includes a dead center rotational speed and a rotational speed maximum, wherein the dead center rotational speed is reached when a cylinder piston of the internal combustion engine is at a top dead center in a power stroke, and wherein the step of determining further includes ascertaining a maximum increase of the rotational speed, starting from the dead center rotational speed up to the rotational speed maximum, wherein the step of determining further includes ascertaining a reference rotational speed, at which a given percentage of the maximum increase is reached, and ascertaining a reference crankshaft angle associated with the reference rotational speed, wherein the step of determining whether a combustion occurs is based on a threshold angle and includes comparing the reference crankshaft angle to the threshold angle and detecting that a combustion occurs when the reference crankshaft angle exceeds the threshold angle.

11. A control device for detecting a combustion process of an internal combustion engine of a hybrid vehicle, the internal combustion engine having a crankshaft and a cylinder piston, the control device comprising:

a signal input configured to acquire a rotational speed signal representing a rotational speed of the crankshaft and a crankshaft angle signal representing a crankshaft angle of the crankshaft; and

a processor configured to determine, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in the internal combustion engine, wherein said processor detects a rotational speed curve shape based on the rotational speed signal, wherein the rotational speed curve shape includes a dead center rotational speed and a rotational speed maximum, wherein the dead center rotational speed is reached when the cylinder piston of the internal combustion engine is at a top dead center in a power stroke, and said processor ascertains a maximum increase of the rotational speed, starting from the dead center rotational speed up to the rotational speed maximum, said processor ascertains a reference rotational speed at which a given percentage of the maximum increase is reached, said processor ascertains a reference crankshaft angle associated with the reference rotational speed, and said processor determines whether a combustion occurs based on a threshold angle and compares the reference crankshaft angle to the threshold angle and detects that a combustion occurs when the reference crankshaft angle exceeds the threshold angle.

12. A hybrid vehicle comprising:

a plurality of drive systems, a first one of said drive systems being configured as an internal combustion engine with a crankshaft and a cylinder piston, a second one of said drive systems being configured as an electric drive;

a control device for detecting a combustion process of the internal combustion engine, said control device acquiring a rotational speed signal representing a rotational speed of said crankshaft and acquiring a crankshaft angle signal representing a crankshaft angle of said crankshaft; and

said control device determining, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in said internal combustion engine, wherein said control device detects a rotational speed curve shape based on the rotational speed signal, wherein the rotational speed curve shape includes a dead center rotational speed and a rotational speed maximum, wherein the dead center rotational speed is reached when said cylinder piston of said internal combustion engine is at a top dead center in a power stroke, and said control device ascertains a maximum increase of the rotational speed, starting from the dead center rotational speed up to the rotational speed maximum, said control device ascertains a reference rotational speed at which a given percentage of the maximum increase is reached, said control device ascertains a reference crankshaft angle associated with the reference rotational speed, and said control device determines whether a combustion occurs based on a threshold angle and compares the reference crankshaft angle to the threshold angle and detects that a combustion occurs when the reference crankshaft angle exceeds the threshold angle.