DE102004030992A1 - Internal combustion engine controlling device for vehicle, has testing unit to provide error value in such a manner that monitoring device determines error during comparison of reference and actual values by monitoring device - Google Patents

Abstract

The device (1) has a monitoring device (280) to compare actual values of an angular position with reference values. A testing unit (240) assigns an error value to a cam shaft adjusting system (300). The system adjusts the position of the shaft based on the error value. The testing unit provides the error value in such a manner that the monitoring device determines an error during the comparison of reference and actual values. An independent claim is also included for a method of controlling an internal combustion engine.

Description

The The invention is based on a method and a device for Control of an internal combustion engine a camshaft adjusting system, wherein a desired value of an angular position with an actual value of the angular position is compared.

variable Valve controls by camshaft adjustment of an internal combustion engine are for example from the essays "Dance of the Valves "as well as" Variable Valve control "the Magazine "mot Profi Special Variable Valve Control ", No. 3/2002, United Motor-Verlag, Stuttgart, known.

The Camshaft adjustment allows a mechanical variation of the valve actuation times on Inlet and outlet of a cylinder chamber. The required Adjustment of the camshaft in the direction of early or late, for example via a Vane phasers or the like by oil pressure. The control of the oil pressure in the individual chambers happens through solenoid valves, which over a pulse width modulated signal, starting from the control unit addressed become. The camshaft must be kept within a Time to reach the setpoint with sufficient accuracy. If not, so it is a mistake. Misalignments during the Variable camshaft adjustment lead among other things to a Waste deterioration due to no longer optimal combustion up to misfiring. Furthermore, the driver a lack of torque or missing power and losses in smoothness such as jerking caused by faulty camshaft positions and resulting filling differences occur between the cylinder banks, complain about.

The Diagnosis of the camshaft control is currently performed by a check of the Adjusting angle of the camshaft. This is the difference between Setpoint and actual value compared with applicable threshold values. In case of or below the threshold values for a period to be applied a setting of a fault of the camshaft adjusting unit takes place. An adjustment error of the camshaft is always set, if after expiry of the debounce time the actual angular position is outside a permissible one Tolerance band is.

From the not pre-published DE 103 40 819 a method for monitoring a camshaft adjustment of an internal combustion engine is known in which a target value of an angular position is compared with an actual value of the angular position, wherein a more differentiated fault diagnosis is achieved ereicht that at least two types of errors can be detected based on the course of the actual value over time. Two possible error types are, for example, a "slow response" error or a "target error". A "slow response" error is detected when, despite an observed angular change, the camshaft phasing system has failed to reach a setpoint or range within a predetermined time.

A "target error "is detected, if the actual value does not even have a certain tolerance range leaves, i.e. the camshaft is stuck.

By This error detection ensures that a malfunction the camshaft adjustment and / or mechanical errors quickly recognized and can be reported to the driver, for example. The potential Affect errors but not only the performance of the internal combustion engine, but worsen by the erroneous operation of the gas exchange valves also the quality the exhaust gas.

For exhaust gas influencing System units, which include the variable camshaft adjustment include write therefore many countries by law, to functionally monitor these system units. Especially It is sometimes required to diagnose more than one possible type of defect.

in the In the simplest case, it can be provided for checking the error monitoring, faulty components that affect the functionality of the camshaft adjustment impair in the vehicle, and to test whether the fault monitoring a Error detected.

to Generation of errors could for example, the flow rate the oil pump be throttled; Flügelradsteller, Solenoid or solenoid valve with leaks or clogged valves be used; or oil pressure or oil viscosity can be manipulated.

Advantages of invention

The device according to the invention with the features of the independent claim has the advantage that the device controls an internal combustion engine with a camshaft adjusting system, wherein the control unit based on target values at least one camshaft adjusted in an angular position, and that a monitoring means, the actual value of the angular position with the A setpoint value is compared and, in the case of deviations which exceed a threshold value, an error is detected that a test means is furthermore provided which, instead of the setpoint value, applies an error value to the Camshaft Verstellsystem transmits and that the camshaft adjustment system adjusts the angular position of the at least one camshaft on the basis of the error value, the error value provided by the test means is such that the monitoring means detects a fault when comparing setpoint and actual value.

Accordingly, directs an advantageous method for controlling an internal combustion engine with a camshaft adjusting from where at least one Camshaft is adjusted based on setpoints and an adjusting itself Actual value of an angular position of at least one camshaft monitored where the actual value is compared with a setpoint and in case of deviations, that exceed a threshold, an error is detected, with the camshaft adjustment system for error simulation instead of the setpoint, an error value is specified, and that the camshaft adjustment system adjusted at least one camshaft on the basis of this error value, and that the error value is such that the deviation of the exceeds the threshold value compared to the setpoint and an error is detected.

By the inventive method and the device according to the invention Thus, the functionality of a monitoring means is advantageously or the monitoring procedure, without that elaborate Interventions on the internal combustion engine and units would be necessary. Of Further there is the possibility this review too outside perform service or repair times and, for example, to automate and to perform independently at given intervals by a control unit.

By in the subclaims listed activities are advantageous developments and improvements in the specified independent claims Device and method possible.

Especially It is advantageous to form the error value as a function of the desired value. So it is possible the error values starting from the setpoints, for example with Help to generate special algorithms. In particular, for Example of smallest but faulty setpoint-actual value deviations generated be like this by "global" error value, the virtually under all circumstances Generate errors in a target / actual comparison is not necessarily possible.

One Another advantage arises when different by pretending Error values, the actual values set so that different Error types are detected. Thus it is possible, not just a principle Response of the monitoring, but specifically to check the detection of different types of errors.

According to one further advantageous embodiment, it is envisaged that the fault simulation based on a coding the setpoint takes place or is started. So is more advantageous Way possible, the functionality the fault simulation permanently, preferably in a control unit, vorzuhalten being the functionality in the daily Insert is hidden based on the setpoint coding. However, as soon as for example by an application device or the control device itself, the generated setpoint values are coded, the error simulation becomes active.

According to one further advantageous embodiment, It is envisaged that based on the coding various fault simulations for different Error types are initiated. This has the advantage that not through elaborate additional data lines a control unit and in particular a test agent in the control unit must be notified, which Type of error type tested shall be. So it is possible in a simple manner, already the setpoint to provide this information by coding, so that all further process steps or control components accordingly can react.

According to one further advantageous embodiment, it is provided that the error value from the setpoint with Help a filter is formed. This is an advantageous way possible, for example too lazy Response of the camshaft adjustment simulate and a corresponding error to generate.

According to one further advantageous embodiment, It is envisaged that different types of errors by changing Parameters of the filter are simulated. That's the way it is possible, by varying, for example, time constants, a different one To simulate the response of the camshaft adjustment. in the In extreme cases, the time constant can be chosen very large, so that the Camshaft not adjusted at all.

drawings

Other features, applications and advantages of the invention will become apparent from the following description of embodiments of the invention, which are illustrated in the drawings. All described or illustrated features, alone or in any combination form the subject matter of the invention, regardless of their summary in the claims or their dependency and independently from their formulation or presentation in the description or in the drawings.

It demonstrate:

1 schematically shows the sequence of setpoint input to the respective actual values;

2 schematically shows a method according to the invention;

3 schematically shows a device according to the invention.

description

The Invention goes from consideration out, an error monitoring system to check for proper functioning by preferring typical errors simulated by an electronic intervention in the control and not by elaborate mechanical Interventions in units and components of the internal combustion engine actually caused become.

According to the invention requires the fault simulation on a camshaft adjustment system substantially the interaction of the following functionalities: a) setpoint specification, b) Camshaft position controller or camshaft adjusting system or else Actuator, c) camshaft diagnosis or monitoring device.

The Setpoint input of the camshaft angle positions offers the option of a Setpoint change limit a changing shape Specified value not directly on the actuator or camshaft position controller to give. This change limit is always designed vehicle specific or individually for an internal combustion engine and bedatet.

Consequently gives the setpoint specification positions and rate of change of position change in front. A faultless functioning camshaft adjusting system, where, for example, no "slow response" behavior and no "target Error "behavior is always in the position of this change in position sufficiently fast and to follow exactly.

at This is not the case with a faulty camshaft adjusting system the case. Thus for the review of the If no faulty actuator is installed in the vehicle must, is over Setpoint filtering within the position controller is faulty Steller simulates.

The Camshaft diagnosis determined from the originally specified setpoint course and the over The position controller simulated slow actual position history for one defective camshaft divider corresponding misalignments in shape of setpoint / actual value differences.

In 1 the sequence for the adjustment of a camshaft adjusting system is shown schematically. Starting from, for example, operating conditions of the internal combustion engine or driver wishes becomes a setpoint specification 10 generated. As described a sudden setpoint specification 10 can not be tracked by mechanical actuators typically, a setpoint is via a setpoint change limit 20 generated, which can be followed quickly and accurately by a perfectly functioning camshaft adjustment system. With numeral 30 is the actual value or the time profile of the angular position, which is at a camshaft when driven with the setpoint 20 adjusts. The signal chain via setpoint specification 10 , Setpoint 20 and actual value 30 thus represents the normal operating case. The actual value 30 is typically at the setpoint 20 compared and signaled an error in impermissible deviations or initiated an error response.

To verify this monitoring agent is a test agent 40 provided, in the present embodiment, starting from the desired value 20 an error value 50 forms, wherein the camshaft adjustment system instead of the setpoint 20 with the error value 50 is controlled so that a corresponding actual value 60 established.

However, the monitoring means still compares the found actual value with the original setpoint value 20 , To check the monitoring means is the error value 50 formed so that the deviation determined in the target / actual comparison is so large that the monitoring means detects an error.

2 schematically shows a possible procedure according to the invention. The upper input arrow symbolizes the incoming setpoint specification, which is limited by a setpoint limitation to a setpoint value 20 in step 120 leads. In a subsequent query step 125 It is checked whether a normal operation or a test operation or a fault simulation is present. In normal operation, the setpoint 20 in step 130 unchanged to the camshaft adjusting system in step 170 transfer. The adjustment of the camshaft is in step 160 monitored and an actual value 30 . 60 the angular position of the camshaft to the step 180 transfer. In the monitoring step 180 becomes the actual value 30 . 60 out of step 160 with the setpoint 20 out of step 120 compared. Depending on the size of the deviations, either a faultless operation or a fault The adjustment of the camshaft continues to be reported to a subsequent process step.

Will in the query step 125 determined that a test operation or a fault simulation is present, step 140 Simulation initiated. In step 140 becomes an error value 50 formed in the step 150 to the camshaft adjusting system in step 170 is transmitted. The adjustment of the camshaft is in step 160 monitored and an actual value 30 . 60 the angular position of the camshaft to the step 180 transfer. In the monitoring step 180 becomes the actual value 30 . 60 out of step 160 with the setpoint 20 out of step 120 compared.

Will the simulated error in step 180 recognized, at least for this detected error is a perfectly functioning monitoring means 180 in front. Depending on the application and test case, all relevant error types can now be checked successively by repeating the simulation loop.

3 schematically shows a device according to the invention 1 for controlling an internal combustion engine 400 with a camshaft adjustment system 300 , The dashed frame symbolizes the entire functionality of a control unit 1 , Within the framework, means for carrying out the method according to the invention are shown schematically. Analogous to the steps described above 120 and 125 is in the control unit 1 a means or module 200 arranged, symbolized by the input arrow a setpoint specification 10 or a setpoint 20 detected and in normal operation the setpoint 20 to a camshaft adjusting system 300 transmits or during a fault simulation or test operation this setpoint 20 to a test agent 240 as well as additionally, independently of the present operating case, the setpoint 20 a monitoring device 280 provides.

Is in the module 200 a test mode is detected, the setpoint 20 no longer to the camshaft adjustment system 300 forwarded. In the test medium 240 becomes an error value 50 formed, and in the subsequent module 250 is used instead of the setpoint 20 the error value 50 to the camshaft adjustment system 300 forwarded. Symbolic are in 3 outside the controller 1 a camshaft adjusting system 300 in conjunction with an internal combustion engine 400 shown. From the actually adjusting by the control angle position on at least one camshaft is in the module 260 an actual value 30 . 60 determined and to the monitoring means 280 forwarded. The monitoring device 280 checks the deviation of the determined actual value 30 . 60 from the desired setpoint 20 In the case of excessively large deviations which, for example, exceed a certain threshold value, an error reaction is initiated in the subsequent process steps or modules. In the case of a fault simulation or a test operation, it is checked in the following modules whether the type of error actually tested by the monitoring means 280 was detected. If necessary, further steps, for example further fault simulations, are initiated.

A fault simulation can be initiated via a codeword according to a possible embodiment. With the help of the code word, for example, the setpoint module 200 and / or the test agent 240 addressed directly and a fault simulation are initiated.

In A preferred variant is the setpoint or already the setpoint input encoded or provided with a code word, so that all subsequent steps and recognize modules based on the coding, whether a normal operation or test operation is present.

Furthermore, in a preferred embodiment, the test agent 240 or the module 250 be designed as a filter. Thus, a "sluggish" reaction of a camshaft adjusting system can be simulated in a simple manner and a "slow response" error can be provoked in the monitoring means.

Bedatet the time constant of the filter with which the setpoint filtering realized at the input of the position controller to the maximum possible value, is the simulation in conjunction with a manual setpoint specification also for a "target Error "Error applicable at any position of the possible adjustment range.

Farther is due to the procedure of the invention the possibility given, an exhaust gas relevant interpretation of the camshaft diagnosis or the monitoring device make.

The camshaft diagnosis evaluates the setpoint during this time 20 the setpoint specification 10 including setpoint change limitation and the actual value that is set.

By the differences between setpoint and actual value the diagnosis the possibility to detect a number of "x" errors. The value that sets at "x" as soon as exceeded the permissible exhaust gas quantity is, as the interpretation of the calibration can be up to the "Malfunction-Identification-Lamp" in the instrument cluster can be controlled, taken over become.

This makes it possible, depending on the number of detected "slow response" error events, an exhaust gas-relevant design to obtain.

Claims (9)

Contraption ( 1 ) for controlling an internal combustion engine ( 400 ) with a camshaft adjusting system ( 300 ) based on setpoints ( 20 ) at least one camshaft adjusted in an angular position, with a monitoring means ( 180 ), which has an actual value ( 30 . 60 ) of the angular position with the desired value ( 20 ) and detects an error in the case of deviations exceeding a threshold, characterized in that a test means ( 240 ) is provided, which instead of the setpoint ( 20 ) an error value ( 50 ) to the camshaft adjusting system ( 300 ) transmits that the camshaft adjustment system ( 300 ) the angular position of the at least one camshaft based on the error value ( 50 ) that the test agent ( 240 ) provided error value ( 15 ) is such that the monitoring means ( 240 ) when comparing setpoint and actual value ( 20 ; 30 . 60 ) detects an error. Method for controlling an internal combustion engine ( 400 ) with a camshaft adjusting system ( 300 ), wherein at least one camshaft based on setpoints ( 20 ) and a self-adjusting actual value ( 30 . 60 ) an angular position of the camshaft is monitored, the actual value ( 30 . 60 ) with a setpoint ( 20 ) and in the case of deviations which exceed a threshold value, an error is recognized, characterized in that, for error simulation, the camshaft adjusting system ( 300 ) instead of the setpoint ( 20 ) an error value ( 50 ) and that the camshaft adjusting system ( 300 ) based on this error value ( 50 ) at least one camshaft adjusted, and that the error value ( 50 ) is such that the deviation of the self-adjusting actual value ( 50 ) compared to the setpoint ( 20 ) exceeds the threshold and an error is detected. Method according to Claim 2, characterized in that the error value ( 50 ) depending on the setpoint ( 20 ) is formed. Method according to Claim 2 or 3, characterized in that by specifying different error values ( 50 ) different actual values ( 30 . 60 ) and thus different errors are simulated. Method according to at least one of the preceding claims 2 to 4, characterized in that a fault simulation based on a coding of the setpoint ( 20 ) he follows. Method according to at least one of the preceding claims 2 to 5, characterized in that different based on the coding Error simulations for various types of errors are initiated. Method according to at least one of the preceding claims 2 to 6, characterized in that the error value ( 50 ) starting from the first setpoint ( 20 ) is formed by means of a filter. Method according to at least one of the preceding claims 2 to 7, characterized in that different types of errors by changing be simulated by parameters of the filter. Device according to claim 1, characterized in that that for the application of one of the methods according to claim 1 to 8 is designed.