EP1605140A2 - Camshaft phaser - Google Patents

Abstract

The adjuster has a control member for adjusting the angle of rotation situation, into an automatic controller (6, 7) for switched automatic control loop. The automatic controller has a data memory (29) having an automatic controller coefficient recording a transfer function. The data memory has two storage areas, and an automatic control loop connected with the help of an operation distribution matrix. The automatic controller coefficient is placed in the data memory range such that a mechanism for the operating condition is provided for the cylinder engine. The automatic controller coefficient is used in dependence on the operating conditions.

Description

The invention relates to an adjusting device for the rotational angular position of the camshaft Reciprocating internal combustion engine relative to the crankshaft, with an actuator for adjusting the angular position, which is connected in a control circuit having at least one controller is.

Such an adjustment device with an actuator, the two over one another in intervention standing gears with helical teeth has, is known from DE 44 08 425 A1. One the gears are connected to the camshaft and the other is connected by a chain of driven by the crankshaft. The gears can by a hydraulic mechanism in the axial Direction are shifted against each other, resulting in due to the helical teeth a relative rotation between the crankshaft and camshaft results. The hydraulic mechanism is controlled by a control signal generated by means of a control loop becomes. The hydraulic mechanism can be controlled with one of three values, namely an early value for adjusting the camshaft in the direction of early opening the intake valves of the internal combustion engine, a late value for adjusting the camshaft towards a late opening of the intake valves and a holding value to hold the current one Actual angular position. The control circuit works off a control program in which at each Program sweep the sweep rate, as at the beginning of the next program sweep will be estimated. From this estimate and the known temporal Behavior, the camshaft adjustment after switching from holding value to has the control signal (early or late value), the adjustment angle is estimated on the the angular position of the camshaft would still change if the actuating signal at the beginning of the would be changed to the holding value next program run. If the deviation between the estimated value for the adjustment angle and the nominal angle position of the camshaft within is a tolerance band, is switched from the early or late value to the holding value. The adjustment speed, as at the beginning of the following program run will probably be present from the current adjustment speed using a Transfer function of first order and a Endverstellgeschwindigkeit estimated. The final adjustment speed is adapted under certain conditions. As specified The disclosure can thereby provide estimates for the current position even then be determined very accurately when operating parameters of the hydraulic mechanism change, e.g. the viscosity of the hydraulic fluid due to a heating of the same. Yet is the control quality of the control loop especially at different operating conditions still in need of improvement. For example, it can be used in certain operating situations an overshoot of the signal to be regulated come.

There is therefore the task of an adjustment of the type mentioned above create in each case a high control quality in different operating situations allows.

The solution to this problem is that the controller connected to a data memory is stored in the controller coefficients for a transfer function of the controller, that the data memory has at least two memory areas in which different Sets of regulator coefficients are stored, that the control loop by means of a mode switching device optionally or alternately with one of the data storage areas is connectable that the stored in the respective data storage area Regulator coefficient set is used in the scheme, and that with the operating mode switching device a device for determining the operating state of the adjusting device and / or the reciprocating internal combustion engine is connected such that the in the regulation in each case applicable regulator coefficient set of the operating state is dependent.

Advantageously, this makes it possible for different operating situations of Adjustment device and / or the internal combustion engine the regulator with different Regulator coefficients to operate the transfer function of the controller to the respective Adapt operating situation and thus each to achieve the highest possible quality control. With such a non-linear regulator can be compared to a controller with fixed Controller coefficients Disturbances in a controlled, to be influenced with the actuator Signal compensated faster and largely avoiding overshoot become. The size (s) by which the controller coefficients are changed can Be measured variables or from these via suitable algorithms including system parameters, such as. an electrical resistance, a temperature coefficient, etc. be derived.

It is advantageous if, with the aid of the operating mode switching device, the structure of the control loop is switchable. The controller can then even better in different operating situations be adapted to the adjusting device and / or the internal combustion engine.

Conveniently, in a first mode of operation of the control loop for controlling the rotor speed the adjusting motor and in a second mode for controlling the angle of rotation formed between the camshaft and crankshaft. Here comes the first mode preferably during the starting phase of the internal combustion engine for use when a measurement signal for crankshaft speed is not yet present or even with relatively large disturbances is afflicted. Once the speed of the engine reaches a preset limit exceeds and thus the start phase is completed, is switched to the second mode, to control the angle of rotation.

In an advantageous embodiment of the invention, the control loop with the help of the operating mode switching device switchable between a third and a fourth operating mode, wherein the control loop in the third mode as a multipoint controller and in the fourth mode is designed to output a continuous control signal.

In a preferred embodiment of the invention, the adjusting device to an adjusting, which is designed as a three-shaft gear with a crankshaft fixed drive shaft, a camshaft fixed output shaft and an adjusting shaft, wherein an adjusting motor is provided as an actuator, which is in driving connection with the adjusting shaft. The adjusting motor can be an EC motor. To control the phase angle velocity θ to a desired value θ _Tgt , the rotational speed ω _{Cnk of} the crankshaft and the rotor rotational speed ω _{Em of} the adjusting _motor are preferably measured with the aid of sensors. From the measurement signals determined in this way and a known stationary gear ratio ig of the variable speed drive, a desired value ω _{Em, Tgt} = (ω _Cnk -i _g θ _Tgt ) / 2 for the rotor speed ω _{Em, Tgt of} the variable displacement _{motor is} calculated with the aid of a signal processing device. The rotational speed ω _{Cnk of} the crankshaft is expediently measured with the aid of an inductive sensor which detects the passage of the teeth of a toothed ring arranged on the crankshaft, for example on a flywheel. The rotor speed ω _{Em of} the variable displacement motor is preferably measured by means of magnetic field sensors arranged on the stator of the EC motor, which detects the passage of magnetic segments which are arranged on the circumference of the permanent magnet rotor of the EC motor.

It is advantageous if the device for determining the operating state at least one Input for a temperature measurement signal of the internal combustion engine and / or the variable displacement motor has, and if the device for determining the operating state is designed such that the governor coefficient set used in the regulation is: This measurement signal (these measurement signals) is dependent. This makes it possible in particular the control circuit to the temperature-dependent viscosity of a transmission oil of the variable transmission and / or at the temperature dependent electrical resistance of the Adapt winding of the adjusting motor. The temperature of the internal combustion engine can for example, measured with a motor oil thermometer and / or a cooling water thermometer become.

In an expedient embodiment of the invention, the device for detection of the operating state, at least one input for a measurement signal and / or a setpoint signal for the angle of rotation between the camshaft and crankshaft, the device for determining the operating state is designed such that in the control respectively Regulator coefficient set used by this signal (these signals) and / or the temporal change of this signal (these signals) is dependent. At a Adjustment device in which the adjustable phase angle range is limited by stops is, can then set the controller coefficients in the area of the stops be that the scheme responds relatively slowly to a control deviation, so that Overshoot and thus the risk of damage to a stop safely avoided becomes. In places where there is sufficient clearance to the stops On the other hand, the controller coefficients can be set to control deviations be compensated as quickly as possible.

The device for determining the operating state may also have at least one input for a the rotor speed of the variable displacement motor, the camshaft speed and / or the crankshaft speed having representative signal, wherein the means for determining of the operating state is designed such that in the control respectively for use coming regulator coefficient set is dependent on this signal (these signals). Each of two of these measurement signals, such as the rotor speed and the crankshaft speed, as well as the known stationary gear ratio of the variable, the angle of rotation (Phase angle) between the camshaft and crankshaft and it determines the Reglerkoeffizienten be adjusted depending on the angle of rotation.

It is advantageous if the device for determining the operating state, a memory for temporarily storing at least one of the controller determined at an earlier time Value of a manipulated variable for the adjusting motor, and if the means for Determining the operating state is designed such that in the control respectively Regulator coefficient set used depends on this value (these values) is. As a result, it is possible, in particular, for low adjustment speeds Provide hysteresis to reduce the noise at the output of the controller.

In a preferred embodiment of the invention, the control circuit has at least one Limiting device, in particular for the winding current and / or the winding voltage the adjusting motor, wherein in the data memory storage locations are provided in which limit values for the limiting device (s) are stored, and that the limiting device using the operating mode switching device optional or alternately is connectable to one of the memory locations that the at least one, in the relevant Storage space respectively stored limit at the limitation to the application comes. The limit values for limiting device (s) can thus depend on the Operating state of the adjusting and / or the reciprocating internal combustion engine set become. For example, in the field of attacks, the limits for the Winding current and / or the winding voltage and thus the power of the adjusting motor be chosen smaller in amount, as in places that are further away from the attacks are, so even if a possible measurement error of an input signal of the controller Damage to the attacks is safely avoided.

It is particularly advantageous if the control loop at least one with at least one pilot control device connected input terminal for a pilot signal, and when Preferably, an input terminal for a speed of the drive shaft of the variable transmission representative pilot signal, an input terminal for a mean load torque the adjusting motor representative pilot signal and / or an input terminal is provided for a pilot signal, the one by the rotation of the permanent magnetic Rotor in a winding of Verstellmotors induced electrical voltage (EMK) represents. The adjustment then allows an even faster and more stable Regulation, the control loop only those deviations between the regulated Equalizes the signal and the setpoint, which are not compensated by the precontrol.

Conveniently, the data memory has at least two memory areas in which different sets of pilot coefficients for the pilot control (s) stored are, wherein the pilot control device (s) by means of a mode switching means optionally or alternately connectable to one of these data storage areas is (are), that the input tax coefficient set stored in the respective data storage area is used in the generation of the at least one pilot signal. Thus, the transfer function (s) of the feedforward control (s) can also be adapted to different Operating conditions of the adjusting device and / or the internal combustion engine be adapted, which allows an even better control quality.

Fig. 1

eine Verstellvorrichtung zum Verstellen der Drehwinkellage der Nockenwelle einer Hubkolben-Verbrennungsmaschine relativ zu deren Kurbelwelle,

Fig. 2

ein Signalflussdiagramm eines Regelkreises der Verstellvorrichtung.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing. Show it:

Fig. 1

an adjusting device for adjusting the rotational angle position of the camshaft of a reciprocating internal combustion engine relative to the crankshaft thereof,

Fig. 2

a signal flow diagram of a control loop of the adjustment.

An adjusting device for the rotational angle position of the camshaft relative to the crankshaft of a in the drawing, not shown reciprocating internal combustion engine has an adjusting mechanism on, as a three-shaft gearbox with a crankshaft-fixed drive shaft, a camshaft-fixed output shaft and an adjusting shaft is formed. The adjusting mechanism may be a planetary gear, preferably a planetary gear.

The drive shaft is rotatably connected to a camshaft gear 1, which in in itself known manner via a chain or a toothed belt with a on the crankshaft of the Internal combustion engine rotatably arranged crankshaft gear in drive connection stands. The output shaft is rotatably connected to the camshaft 2, which in Fig. 1 only partially is shown. The adjusting is rotatably connected to an actuator, in Fig. 1 at the rear side of the adjusting device is arranged. Actuator is an adjustment motor (EC motor) provided, which is integrated in the hub of the camshaft gear 1.

To limit the angle of rotation between the camshaft and the crankshaft, the Adjustment device stops on, by a fixedly connected to the drive shaft stop element 3 and counter-stop elements 4 are formed. The counter-stop elements 4 are firmly connected to the camshaft 2 and act in the use position with the stop element 3 together.

To control the angle of rotation of the adjusting motor is in a in Fig. 2 schematically illustrated Connected control circuit 5, which has two cascaded controller, namely a speed controller 6 and an upstream of this phase controller. 7

An input terminal of the phase controller 7 is connected to an output _terminal 8 of a first device 9 for determining a control deviation from a setpoint _signal ε _Tgt and an actual value signal ε for the displacement angle of the camshaft 2 relative to the crankshaft. In FIG. 2 it can be seen that the phase controller 7 has two signal processing devices 10, 11 which are each connected with their input to the output terminal 7 of the device 9 for determining a control deviation. A first signal processing device 10 has a first transfer function with first regulator coefficients K ₁ and a second signal processing device 11 has a second transfer function with second regulator coefficients K ₂ . An output of the first signal processing device 10 is connected to a first input of a first summation device 13 and an output of the second signal processing device 11 is connected via a first integration device 12 to a second input of the first summation device 13.

An output of the first summation device 13 is connected to a first input of a second summation device 14. An input connection 15 for a crankshaft speed _signal ω _Cnk is connected via a first pilot control _device 16 to a second input of the second summation device 14. The first pilot control device 16 has a first pilot control transfer function with first pilot coefficients V ₁ .

An output of the second summation device 14 is connected via a first limiting device 17, which limits the output signal to a predetermined value range, to an output connection for a speed _{setpoint signal .omega.Tgt} for the variable displacement _motor .

The speed _{setpoint signal} ω _Tgt is applied to a first input of a second device 18 for determining a control deviation from the speed _{setpoint signal} ω _Tgt and an actual value signal ω _Em for the speed of the variable displacement motor.

The speed controller 6 has two signal processing devices 19, 20, which are each connected at their input to an output terminal 21 of the second device 18 for determining the control deviation. A third signal processing device 19 has a third transfer function with third regulator coefficients K ₃ and a fourth second signal processing device 11 has a fourth transfer function with fourth regulator coefficients K ₄ . An output of the third signal processing device 19 is connected to a first input of a third summation device 22 and an output of the fourth signal processing device 20 is connected via a second integration device 23 to a second input of the third summation device 22.

An output of the third summation device 22 is connected to a first input of a fourth summation device 24. An input connection 25 for an adjusting motor _load signal M _Load is connected via a second pilot control device 26 to a second input of the fourth summation device 24. The second pilot control device 26 has a second pilot control transfer function with second pilot coefficients V ₂ .

An output of the fourth summation device 24 is connected via a second limiting device 27, which serves to limit the to be output to the adjusting winding voltage U _A to a predetermined range of values, connected to an input terminal of a drive means not shown in the drawing for the adjusting motor.

In FIG. 2 it can be seen that the speed controller 6 and the phase controller 7 are connected via an operating mode switching device 28 to a data memory 29 which has a plurality of data storage areas, in each of which a set of regulator coefficients is stored, each having first controller coefficients K ₁ , second regulator coefficients K ₂ , third regulator coefficients K ₃ and fourth regulator coefficients K ₄ . In the data memory 29 also a plurality of data storage areas are provided, in each of which a set of precontrol coefficients is stored, each comprising the first precontrol coefficients V ₁ and second precontrol coefficients V ₂ .

The speed controller 6 and the phase controller 7 are using the operating mode switching device 28 optionally or alternately connectable to one of the data storage areas, that the regulator coefficient set stored in the respective data storage area in the scheme and / or stored in the respective data storage area respectively Precontrol coefficient set is used (come) in the pre-control.

As can be further seen in FIG. 2, with the operating mode switching device 28 and the Data memory 29, a device 30 for determining the operating state of the adjusting device and the reciprocating internal combustion engine connected such that in the control each applicable Reglerkoeffizientensatz and / or the pilot control each applicable input tax coefficient rate depends on the operating state is. The device 30 for determining the operating state has several inputs that with Sensors for measuring the crankshaft speed, the oil temperature of the internal combustion engine, the speed of the adjusting motor, an output of the second limiting means 27 and connected to an output terminal of an engine controller for the internal combustion engine a signal for an operating mode (engine start / stop, normal running, emergency) of the internal combustion engine is applied. The device 30 for determining the operating state has a Comparison device on which the signals applied to the inputs with predetermined Value ranges compares. Depending on the results of these comparisons, will determines an operating state which determines the selection of the respective controller and control coefficient sets.

The operating mode switching device 28 also allows a changeover of the structure of the control loop. In a first operating mode of the control loop, the regulator coefficients K ₁ , K ₂ and the precontrol coefficients V _{1 have} the value zero, while the regulator coefficients K ₃ , K ₄ and the precontrol coefficients V _{2 are} not equal to zero. The control circuit 5 then controls only the rotor speed of the adjusting motor. This operating mode is preferably used during the starting phase of the internal combustion engine.

In a second operating mode of the control loop, all the regulator coefficients K ₁ , K ₂ , K ₃ , K ₄ and pilot control coefficients V ₁ , V _{2 are} not equal to zero, so that the control circuit 5 then controls the angle of rotation between the camshaft 2 and the crankshaft and the rotor speed. The second operating mode is used when the speed of the internal combustion engine exceeds a predetermined minimum value.

LIST OF REFERENCE NUMBERS

1

camshaft gear

2

camshaft

3

stop element

4

Counter-stop element

5

loop

6

Speed controller

7

Phase regulator

8th

output port

9

first device for determining a control deviation

10

first signal processing device

11

second signal processing device

12

first integration device

13

first summation device

14

second summation device

15

Input _terminal for a crankshaft speed signal ω _Cnk

16

first pilot control device

17

first limiting device

18

second device for determining a control deviation

19

third signal processing device

20

fourth signal processing device

21

output port

22

third summation device

23

second integration device

24

fourth summation device

25

Input connection for an adjustment motor _load signal M _Load

26

second pilot control device

27

second limiting device

28

mode switching

29

data storage

30

Device for determining the operating condition

Claims (12)

Adjusting device for the rotational position of the camshaft (2) of a reciprocating internal combustion engine relative to the crankshaft, with an actuator for adjusting the angular position, which is in a at least one controller (6, 7) having control circuit (5), characterized in that the controller (6, 7) is connected to a data memory (29), are stored in the controller coefficients for a transfer function of the controller (6, 7) that the data memory (29) has at least two memory areas in which different sets of regulator coefficients are stored in that the control circuit (5) is selectively or alternately connectable to one of the data memory areas by means of a mode switching device (28), that the controller coefficient set stored in the relevant data memory area is used in the control, and in that a mode switching means (28) Device (30) for determining the operating condition ds the adjusting device and / or the reciprocating internal combustion engine is connected such that the respectively used in the control respectively applicable regulator coefficient set is dependent on the operating state. Adjusting device according to claim 1, characterized in that the structure of the control circuit (5) can be switched over with the aid of the operating mode switching device (28). Adjusting device according to claim 1 or 2, characterized in that in a first operating mode the control circuit (5) is designed to control the rotor speed of the adjusting motor and in a second operating mode to control the angle of rotation between the camshaft (2) and crankshaft. Adjusting device according to one of Claims 1 to 3, characterized in that the control circuit (5) can be switched between a third and a fourth operating mode with the aid of the operating mode switching device (28), and that the control circuit (5) in the third operating mode acts as a multipoint controller and in the fourth mode is designed to output a continuous control signal. Adjusting device according to one of claims 1 to 4, characterized in that it comprises an adjusting gear, which is designed as a three-shaft gear with a crankshaft fixed drive shaft, a camshaft fixed output shaft and an adjusting, and that an adjusting motor is provided as an actuator which is in driving connection with the adjusting shaft , Adjusting device according to one of claims 1 to 5, characterized in that the device (30) for determining the operating state has at least one input for a temperature measurement signal of the internal combustion engine and / or the variable displacement motor, and that the means (30) for determining the operating state is formed in that the regulator coefficient set used in the regulation depends on this measurement signal (these measurement signals). Adjusting device according to one of claims 1 to 6, characterized in that the means (30) for determining the operating state has at least one input for a measurement signal and / or a setpoint signal for the angle of rotation between the camshaft and crankshaft, and that the means for determining the operating state (30) is designed in such a way that the regulator coefficient set used in the regulation depends on this signal (s) and / or the temporal change of this signal (s). Adjusting device according to one of claims 1 to 7, characterized in that the means (30) for determining the operating state has at least one input for a rotor speed of the adjusting motor, the camshaft speed and / or the crankshaft speed representative signal, and that the means (30) for determining the operating state is designed such that the regulator coefficient set used in each case for the control of this signal (these signals) is dependent. Adjusting device according to one of claims 1 to 8, characterized in that the means (30) for determining the operating state comprises a memory for temporarily storing at least one previously determined by the controller (6, 7) value of a manipulated variable for the variable displacement motor, and in that the device (30) for determining the operating state is designed in such a way that the regulator coefficient set used in the regulation depends on this value (these values). Adjusting device according to one of claims 1 to 9, characterized in that the control circuit (5) has at least one limiting device (17, 27), in particular for the winding current and / or the winding voltage of the adjustment that storage locations are provided in the data memory (29) in which limiting values for the limiting device (s) (17, 27) are stored, and that the limiting device (17, 27) can be selectively or alternately connected to one of the memory locations by means of the operating mode switching device (28) such that the at least one , in the relevant storage space each stored limit is applied to the limitation. Adjusting device according to one of Claims 1 to 10, characterized in that the control circuit (5) has at least one input connection (15, 25) for at least one pilot control device (16, 26) for a pilot control signal, and in that preferably an input connection (15) for an input signal (25) is provided for a pilot control signal representing the average load torque of the variable displacement motor and / or an input port for a pilot control signal which is an electrical induced by the rotation of the permanent magnet rotor in a winding of the variable displacement motor Voltage (EMF) represents. Adjusting device according to one of claims 1 to 11, characterized in that the data memory has at least two memory areas in which different sets of pilot coefficients for the pilot control (s) are stored, and that the pilot control device (s) using the operating mode switching means (28) choice or alternately connectable to one of these data memory areas such that the pre-control coefficient set respectively stored in the respective data memory area is used in the generation of the at least one pre-control signal.

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