DE102005030185A1 - Method for referencing of incremental travel sensor in electronically controlled operating device of clutch in vehicle entails determining actual position of operating element from actual clutch torque and stored characteristic - Google Patents

Abstract

The method is for the referencing of an incremental travel sensor (23) in an electronically controlled operating device (10,24) of a clutch (22) in the drive train of a moving vehicle in which the operating device has a memory in which a characteristic is stored which determines the clutch torque depending upon the position of an operating element (20). The method entails determining whether the clutch slips beyond a threshold and if the result is in the affirmative determining the actual clutch torque, and determining the actual position of the operating element from the actual clutch torque and the stored characteristic. An independent claim is included for a device for the referencing of an incremental travel sensor in an electronically controlled operating device of a clutch in the drive train of vehicle.

Description

The The invention relates to a method and a device for referencing an incremental travel sensor in an electronically controlled actuator a clutch in the drive train of a vehicle.

Automatic clutches are finding increasing use in automobiles not only for convenience but also for reasons of fuel economy. Actuators of such automated clutches often include an incremental sensor that incrementally senses the travel of an actuator of the clutch or the rotation of an actuator, such as an electric motor. Precise knowledge of the position of the actuator is required for accurate control of the clutch actuation, since in most applications the clutch is controlled to transmit a predetermined torque dependent on the position of the actuator. This clutch torque is stored in an electronic memory as a characteristic depending on the position of the actuator. It is therefore necessary to match the signal of the incremental sensor from time to time, ie to set the actuator to a reference value to which the count of the incremental sensor can then be referenced. This referencing is usually done at a stop. In the DE 199 53 292 A1 a method is described in which it is decided depending on various input signals, whether the referencing of the Inkrementalwegmessung should be done with the clutch closed or when open.

The Referencing a clutch actuator to a stop requires that depending on the design of the operation the coupling, which can be done in different ways, the Clutch either completely closed or complete open must become. This complete Close or open the Clutch is only possible in certain situations, so that delays between Request and execution Referencing is inevitable.

Of the Invention is based on the object, a method and an apparatus for its implementation specify that the referencing permits as close as possible to requirements.

• – Bestimmen, ob die Kupplung überschwellig schlupft; falls ja
• – Bestimmen des aktuellen Kupplungsmoments und
• – Bestimmen der aktuellen Stellung des Betätigungselements aus dem aktuellen Kupplungsmoment und der Kennlinie.

A first solution of this object is achieved by a method for referencing an incremental sensor in an electronically controlled actuator of a clutch in the drive train of a moving vehicle, which actuator includes a memory in which a characteristic is stored, which indicates the clutch torque depending on the position of an actuating element which method contains the following steps:

• Determining whether the clutch is slipping suprathreshold; if so
• - Determining the current clutch torque and
• - Determining the current position of the actuator from the current clutch torque and the characteristic.

With In the aforementioned method, the incremental travel sensor can at least roughly referenced when the vehicle is moving.

mit

MK

= Kupplungsmoment

MM

= Motormoment

J

= Trägheitsmoment des Motors und

= zeitliche Drehzahländerung des Motors

Advantageously, the current clutch torque is determined according to the following relationship:

With

MK

= Clutch torque

MM

= Engine torque

J

= Moment of inertia of the engine and

= temporal speed change of the motor

Of the Slip is advantageously achieved by comparing a clutch input side Engine speed with a clutch output side transmission input speed determined.

While the Engine speed is usually immediately available, is a sensor for the transmission input speed not always available. In this case, the transmission input speed can be off the current gear ratio, the axle ratio and the current vehicle speed are determined.

Advantageous is the current target clutch torque after determining the current Set clutch torque to this actual clutch torque, so that no jump occurs in the clutch torque.

• – Bestimmen, ob die Kupplung überschwellig schlupft; falls nein
• – Bestimmen, ob ein Gang eingelegt ist; falls ja
• – Kupplung voll schließen, bis die Betätigungsvorrichtung einen Schließ-Referenzanschlag erreicht.

A further solution of the invention task is achieved with a method for referencing an incremental travel sensor in an electronically controlled actuating device of a clutch in the drive train of a moving vehicle, which method comprises the following steps:

• Determining whether the clutch is slipping suprathreshold; if not
• Determining whether a gear is engaged; if so
• - Fully close the clutch until the actuation reached a closing reference stop.

The The aforementioned method is feasible when the vehicle is moving, if the clutch slips only slightly.

• – Bestimmen, ob die Kupplung überschwellig schlupft; falls nein
• – Bestimmen, ob ein Gang eingelegt ist; falls nein
• – Kupplung voll öffnen oder schließen, bis die Betätigungsvorrichtung einen Referenzanschlag erreicht.

A further solution to the problem of the invention is provided by a method for referencing an incremental travel sensor in an electronically controlled actuating device of a clutch in the drive train of a moving vehicle, which method comprises the following steps:

• Determining whether the clutch is slipping suprathreshold; if not
• Determining whether a gear is engaged; if not
• - Fully open or close the clutch until the actuator reaches a reference stop.

One subliminal slip state can be brought about, for example, by reducing the engine torque.

In order to after a reset a rapid referencing is possible, it is advantageous a current gear in an EEPROM of the actuator after change each of the hallway.

there is also advantageous before starting to lay out an old aisle to set an additional signal to "no gear" and to Put a new gear in gear.

• – vollständiges Öffnen der Kupplung und Referenzieren des der Kupplungsbetätigungsvorrichtung zugeordneten Inkrementalwegsensors in der voll geöffneten Stellung der Kupplung,
• – Beibehalten der voll geöffneten Stellung der Kupplung und Referenzieren des (der) der Getriebebetätigungsvorrichtung zugeordneten Inkrementalwegsensors(en),
• – Schalten des Getriebes in Neutralstellung und
• – vollständiges Schließen der Kupplung und Referenzieren des der Kupplungsbetätigungsvorrichtung zugeordneten Inkrementalwegsensors in der voll geschlossenen Stellung der Kupplung.

A further solution to the problem of the invention lies in a method for referencing an incremental travel sensor in an electronically controlled actuation device of a clutch and at least one further incremental travel sensor in an electronically controlled actuation device of a transmission in a vehicle drive train after a reset, in particular undervoltage reset, which method comprises the following steps:

• Fully opening the clutch and referencing the incremental travel sensor associated with the clutch actuator in the fully open position of the clutch,
• Maintaining the fully open position of the clutch and referencing the incremental travel sensor (s) associated with the transmission actuating device,
• - Switching the transmission in neutral position and
• - Completely closing the clutch and referencing the incremental travel sensor associated with the clutch actuator in the fully closed position of the clutch.

The inventive method are not limited to automated clutches of manual transmissions, automated manual transmissions, automatic transmissions or Driven with continuously variable transmission can be used, but also on parallel transmissions or dual-clutch transmissions, in each case by closing a Clutch one of two transmission branches is activated, so that the other transmission branch are switched with the clutch open can.

Of the directed to the device part of the invention task is with a device for referencing an incremental sensor in an electronically controlled actuator of a clutch dissolved in the drive train of a vehicle, which actuator a microprocessor with a memory device, in the a characteristic is stored, which depends on the clutch torque the position of an actuating element indicates and to which the incremental sensor, other sensors and at least an actuator of the actuator are connected, wherein programs in the memory device such are included, that the device at least one of the methods according to one of the preceding claims.

The Invention will be described below with reference to schematic drawings, for example and explained in more detail.

In the figures represent:

1 a principle of a clutch actuator,

2 one in a memory of the control unit according to 1 stored torque characteristic, and

3 to 5 Flow diagrams for explaining the method according to the invention.

According to 1 has an actuator known in its construction known per se for a clutch actuator 10 , For example, an electric motor, on, one with a worm toothing 12 provided spindle 14 rotatably driving. The worm gearing 12 engages in a toothing of a segment wheel 16 a, which is pivotally mounted about an axis A and to which a transmission member 18 is stored, with an actuator 20 a clutch 22 , For example, a release lever is connected.

The rotation of the spindle 14 is from an incremental sensor 23 , In the example shown, an incremental angle sensor detected whose pulses an electronic control unit 24 fed who the. The segment wheel 16 is pivotable about an angular range by stops 24 and 26 is limited, wherein the one stop of the fully engaged position of the clutch 22 and the other stop the fully disengaged position of the clutch 22 equivalent. Reaching a stop is from the controller that controls the actuator 10 controls, in each case recognizable by the fact that, in spite of energized actuator, the incremental sensor 23 no more impulses. In this way, the end positions of the clutch or the actuator 20 be referenced.

Inputs of the control unit are connected to other sensors of the drive train, not shown, such as a sensor for detecting the rotational speed of a drive motor of the drive train, a sensor for detecting the translation of the transmission, not shown, a sensor for detecting the rotational speed of a transmission input shaft, a sensor for detecting the Speed of the vehicle, etc. Outputs of the control unit 24 control the actor 10 and other actuators, such as a dialing actuator and a switching actuator of an automated manual transmission.

Of the Structure and function of the arrangement described are in themselves are known and therefore not explained.

2 shows one in a memory of the control unit 24 filed clutch torque curve, wherein the abscissa is the position x of the actuator 20 and the ordinate indicates the respectively transmissible clutch torque MK. The position x0 corresponds to the fully open position of the coupling, the position x1 corresponds to the fully closed position of the coupling.

The count of the incremental sensor 23 , on the control unit 24 is evaluated and a certain position of the segment wheel 16 may change during operation as a result of different influences, such as wear, temperature, etc., or must be re-read or adjusted for example after a reset.

For precise control of the clutch, it is important to have the instantaneous association between transmissible clutch torque MK and the position of the actuator 20 to know exactly. A start of the attacks 26 or 28 is possible only in certain operating states of the vehicle, without the vehicle operation is impaired.

wobei MM das augenblickliche Moment des die Eingangsseite der Kupplung beaufschlagenden Antriebsmotors, beispielsweise eines Verbrennungsmotors, ist, J das Trägheitsmoment des Verbrennungsmotors ist und

die zeitliche Änderung der Drehzahl der Kurbelwelle des Verbrennungsmotors bzw. die Beschleunigung der Kurbelwelle ist.According to the invention, in slip phases, the current clutch torque MK is determined according to the following relationship:

where MM is the instantaneous moment of the input side of the clutch impinging drive motor, such as an internal combustion engine, J is the moment of inertia of the internal combustion engine and

the time change of the rotational speed of the crankshaft of the internal combustion engine or the acceleration of the crankshaft.

das übertragbare Kupplungsmoment MK ermittelt. Das Motormoment wird einem im Steuergerät abgelegten Motorkennfeld entnommen, in dem das Motormoment abhängig von der Stellung eines Leistungsstellgliedes und der Drehzahl des Motors sowie ggf. weiteren Einflussgrößen abgelegt ist.Based on the flowchart of 3 the procedure of a referencing is explained:
In step 40 starts in the control unit 24 stored program a referencing. In step 42 determines the input speed of the gearbox nGE, which is also the output speed of the clutch. In step 44 Based on plausibilities, such as the determined vehicle speed, the instantaneous gear ratio and the axle ratio (from these variables, the transmission input speed can also be determined) checks whether the transmission input speed nGE was determined correctly. If so, the program proceeds to the step 46 in which it is checked whether the slip S is greater than a slip limit SGW. The slip is determined by comparing the engine speed, which is also the clutch input speed, with the transmission input speed. If the slip is above the slip limit SGW, then in step 48 using the formula

determines the transmissible clutch torque MK. The engine torque is taken from an engine map stored in the control unit, in which the engine torque is stored as a function of the position of a power actuator and the speed of the engine and possibly other influencing variables.

In step 50 is then determined on the basis of the clutch torque characteristic ( 2 ) from the step 48 certain transmittable coupling torque MK, which in 2 is referred to as Mr (reference torque), the current position xakt of the clutch operating member (in 2 denoted by xr, reference position). The current position xr can now be used as the reference position to which the count of the increment counter 22 ( 1 ). That in a program of the control unit 24 stored, respectively to be approached clutch torque is on the in 48 set certain current clutch torque, whereby a jump in the clutch torque or a sudden operation of the clutch can be avoided.

In the event that no transmission input speed nGE can be determined (no in step 44 ), or that in the step 46 determined slip S is less than or equal to the slip limit SGW, the program proceeds to the step 56 in which the following can be done:
If a gear is engaged and the slip is less than the slip limit SGW, the clutch can be completely closed until in the example of 1 the fully closed position of the clutch corresponding to the stops 26 and 28 has started. This position serves as a new reference position.

In order to bring the slip below the slip limit if necessary, the slip S by a motor intervention, eg by appropriate control of an actuator of a load actuator, by means of the control unit 24 be reduced to a value less than the limit. If, during the reduction of the engine torque, the clutch torque is kept constant, the slip decreases and it can be a referencing by approaching the fully closed clutch corresponding stop. The vehicle loses while momentarily to traction; however, this loss of traction is much smaller than the loss of traction associated with fully opening the clutch and starting the corresponding other stop. Furthermore, no gear must be designed so that the full traction can be restored quickly.

In the case, that the transmission input speed can not be determined can the clutch are actuated to one of the stops. Then you can a reference run is carried out in the neutral position of the gearbox, making sure that no gear is engaged and the Transmission sensors can be adjusted. Thereafter, the actuator the clutch by starting the fully closed or full open Be referenced stop.

In the case of a parallel gearbox, if no further information is known or the validity of the information is not guaranteed, the adjustment must be performed as follows:
Both couplings are opened by groping. The clutches are actuated at the same time or offset in the direction of opening. At the same time the movement is observed. If movement no longer takes place as a result of a stop, the opening is ended. Knowing the system, it can now be assumed that the clutches are open, ie the drivetrain is open.

Subsequently, will performed a neutral reference ride, in which the drive train by opening the clutches is open, so that in the transmission any movements carried out can be. With Help of the neutral reference travel is groping in the gearbox and approached a defined position for reference purposes. there the gearbox sensors can be compared. Then both can Clutches at any of their stops matched or referenced become.

Based on 4 will be explained below how the transmission input speed nGE can be determined:
In step 421 it is determined whether a sensor for detecting the transmission input speed is present. If this is the case, then in step 422 the transmission input speed nGE derived directly from the sensor signal.

If the sensor is missing, it will be in step 423 the current gear of the transmission is determined and in step 424 Checks whether the currently engaged gear Gakt could be safely determined as gear y. If yes, in step 425 the transmission input speed is calculated from the vehicle speed v, the axle ratio iA and the current gear ratio iy, so that in this way the transmission input speed nGE is also determined and the determination of the transmission input speed nGE in step 426 ends.

Will in step 424 found that the currently switched gear can not be determined with certainty, so is in the step 427 set that over the way 423 and 424 the transmission input speed nGE can not be determined.

It is understood that the results of the steps 422 and 425 in step 44 can be compared with each other, so that the determined transmission input speed nGE can be determined with certainty as correct.

Based on 5 is explained below how the current gear Gakt in step 423 can be determined:
Normally, the current gear is known from a gear position sensor mounted on the gear. After a reset, for example as a result of undervoltage, to which a referencing must take place, the gear position sensor must also be re-referenced, so that from there the current gear is not known. The RAM area of one in the controller 24 often has a special area "Buffered RAM", the content of which is retained at a reset and checked for correctness. When reset by undervoltage but also the buffered RAM is deleted. In order to be able to determine the current gear, it is stored in the EEPROM after each change of the gear. In order to be able to decide whether the value stored in the EEPROM is valid when requesting a compensation of a referencing after an undervoltage reset, a further signal is required. This additional signal is always set to "no gear" prior to the beginning of the laying out of the old gear and set to "gear" as soon as the new gear is fully engaged and its number stored in the EEPROM was chert.

According to 5 is in the step 4231 Check if the Buffered RAM area is OK. If this is the case, then in step 4232 the gear stored in the buffered RAM is read out as the current gear and the gear determination program proceeds to the end 4233 , If the buffered RAM is not in order (for example, deleted), then in step 4234 determines whether the additional signal is set to gear. For example, the value of the additional signal set to "gear" is 1 and the value of the additional signal set to "no gear" is 0. If the additional signal is in "gear", then in step 4235 the current gear is read from the EEPROM and the program is terminated.

Will in step 4234 If it is determined that the additional signal is "no gear", then in step 4236 determined that a safe gear determination is not possible and thus the transmission input speed in step 427 ( 4 ) can not be determined.

With The method exemplified above is as far as possible if required, rapid referencing or rapid reconciliation the actuator possible.

• – Eine der beiden Kupplungen muss offen sein, so dass das gesamte Motormoment über die andere, schlupfende Kupplung übertragen wird.
• – In dem Getriebezweig, der der schlupfenden Kupplung nachgeordnet ist, muss ein Gang eingelegt sein.

The described methods can be applied not only to a transmission with a single clutch, but also in parallel shift transmission systems:
In order to derive the clutch torque from the engine torque and the product of the moment of inertia of the motor and the angular acceleration of its speed at suprathreshold slip in parallel transmissions, the following basic requirements must be met:

• - One of the two clutches must be open so that all engine torque is transmitted through the other, slipping clutch.
• - In the transmission branch, which is subordinate to the slipping clutch, a gear must be engaged.

Around decide at any time, especially after a reset to be able to Whether these prerequisites are fulfilled can provide corresponding status data stored in buffered RAM and / or EEPROM. To the fact To take into account that saving in the EEPROM several hundred It can take milliseconds, it is always important to add one Store information indicating whether the information stored in the EEPROM valid are or not. Before the information in the EEPROM is changed, must their invalidity are displayed. The invalidity may in each case only after the complete change withdrawn become.

at an undervoltage reset knows a system for operating a automatic clutch and an automatic transmission no longer the Absolute positions of the respective actuators, so that a Referencing is required. Such referencing can advantageously be made by first that the clutch groping open and the clutch operation assigned incremental travel sensor referenced with fully open clutch or is adjusted. Subsequently can be at fully open Clutch the transmission are referenced by its reference positions be approached. Subsequently the transmission can be switched to its neutral position and the closed position of the coupling are referenced, so that the Coupling and the Gear actuator fully operational again are.

The The aforementioned referencing can work both with a clutch used in automatic transmissions as well as in parallel transmissions which work with two clutches, for example.

The the aforementioned method can be suitably combined with each other and it can Features of a method used in other methods.

10

actuator

12

worm gear

14

spindle

16

segmented

18

transmission member

20

actuator

22

clutch

23

Inkrementalwegsensor

24

control unit

26

attack

28

attack

Claims (13)

A method for referencing an incremental path sensor in an electronically controlled actuator of a clutch in the drive train of a moving vehicle, which actuator includes a memory in which a characteristic is stored, indicating the clutch torque depending on the position of an actuator, which method comprises the steps of: - determining whether the clutch slips suprathreshold; if yes - determining the current clutch torque and - determining the current position of the actuator from the current clutch torque and the characteristic. The method of claim 1, wherein the current clutch torque is determined according to the following relationship:

with M _K = clutch torque M _M = engine torque J = moment of inertia of the engine and

= temporal speed change of the motor The method of claim 1 or 2, wherein the slip by comparing a clutch input side engine speed determined with a clutch output side transmission input speed becomes. The method of claim 3, wherein the transmission input speed from the current gear ratio, the axle ratio and the instantaneous vehicle speed is determined. Method according to one of claims 1 to 3, wherein after determination the current clutch torque the current target clutch torque is set to the current clutch torque. Method for referencing an incremental path sensor in an electronically controlled actuator of a clutch in the drive train of a moving vehicle, which method the following Steps contains: Determine whether the clutch slips suprathreshold; if not Determine whether a gear is engaged; if so - Close the clutch fully until the actuator a closing reference stop reached. The method of claim 6, wherein a subliminal Slip state brought about is by the engine torque is reduced. Method for referencing an incremental path sensor in an electronically controlled actuator of a clutch in the drive train of a moving vehicle, which method the following Steps contains: Determine whether the clutch slips suprathreshold; if not Determine whether a gear is engaged; if not - fully open the clutch or shut down, until the actuator reached a closing reference stop. Method according to one of claims 1 to 8, wherein a current Gear in an EEPROM of the actuator after change the gear is stored. Method according to claim 9, wherein before the beginning of the Placing an old gear an auxiliary signal is set to "no gear" and is set to "gear" after inserting a new gear. Method for referencing an incremental path sensor in an electronically controlled actuator of a clutch and at least one further Inkrementalwegsensors in an electronic controlled actuator a transmission in a vehicle driveline after a reset, in particular undervoltage reset, comprising the following steps: - completely open the Coupling and referencing of the clutch actuator associated Incremental travel sensor in the fully open position of the clutch, - Maintain the fully opened Positioning of the clutch and referencing of the transmission operating device (s) assigned incremental travel sensor (s), - Switching the gearbox in Neutral position and - completely close the Coupling and referencing of the clutch actuator associated Inkrementalwegsensors in the fully closed position of the clutch. Method according to one of claims 1 to 11, which method for the Couplings of a parallel gearbox is performed. Device for referencing an incremental path sensor ( 23 ) in an electronically controlled actuator ( 10 . 24 ) a coupling ( 22 ) in the drive train of a vehicle, which actuator includes a microprocessor with a memory device in which a characteristic is stored, the clutch torque depending on the position of an actuating element ( 20 ) and to which the incremental displacement sensor, further sensors and at least one actuator ( 10 ) are connected to the actuating device, wherein programs are contained in the memory device such that the device performs at least one of the methods according to one of claims 1 to 12.