FR2787160A1 - Motor vehicle with automatic coupling actuator has sensor that detects gear setting/gear change process; if gear change process is hindered, coupling is engaged at least partly, temporarily - Google Patents

Abstract

The vehicle has a device for automatically operating a coupling or clutch (2) with an actuator (5) and an electronic control unit (6), a gearbox (3) and a gearbox actuating element. The control unit controls actuation when starting, changing gear and stopping. At least one sensor detects the gearbox gear setting and/or a gear change process. If the gear change process is hindered the coupling is engaged at least partly and at least temporarily.

Description

The invention relates to a motor vehicle comprising a device for

  operate a torque transmission system, such as a friction clutch. The invention further relates to a method for using such a device in particular in a motor vehicle. Such motor vehicles comprising such devices can control, in a targeted manner, the torque that can be transmitted by a transmission system

of couple.

  If in such a motor vehicle comprising such a device and equipped with a clutch that can be actuated in an automated manner and a transmission, while the clutch is open, an attempt is made to engage a gear, it may happen that the operation of engagement of speed is hindered before this operation is completed when speed is engaged. For example, the teeth of two pinions of a switching group can meet during the speed change operation so that the speed cannot be fully engaged. This can be the case for example during unsynchronized speed commitments or even in the case of

synchronized speed.

  Such devices are known for example from US Patent 5,595,550. US Patent 5,595,550 thus proposes, in such a case, to switch over to the neutral of the transmission and to actuate the pedal.

  accelerator so that the clutch is engaged

  above an idle speed. Subsequently, switching must be performed again at the intended speed. This method has a disadvantage, however, since the driver must identify the state and must go into the neutral position, and then he must increase the speed of rotation of the engine by actuating an accelerator pedal, and then he must again perform switching to the envisaged speed. A driver of the vehicle must therefore take a step which is uncomfortable for him and which may not be obvious to him and which takes a certain time. Therefore the driver cannot

  start or continue moving directly.

  According to the invention, this is obtained in a motor vehicle comprising a device for the automated actuation of a clutch, comprising an actuator and an electronic control unit, a transmission provided with an element for actuating this transmission, in which a control unit controls the actuation for starting, during a gear change and when stopping, and in which there is provided at least one sensor which detects the engaged speed of the transmission and / or a process of gear change, due to the fact that when the gearshift process is blocked

  speed, the clutch is engaged at least partially.

  This implies that at least at times a torque is set, which can be transmitted by the clutch and which is located

  between the value 0 and the maximum value so that when

  as the engine turns, the input shaft of the transmission turns at least slightly. As a result, since the teeth, which are pressed against each other, pinions rotate slightly and the speed can be

immediately engaged.

  It is particularly advantageous if the sensor used to detect the speed engaged in the transmission is or comprises a sensor, which detects the travel of movement of a switching element in a switching channel for the speed change. It is also advantageous if the sensor for detecting the engaged speed of the transmission is or comprises a sensor, which detects the travel of movement of a switching element between switching paths or along a selection path for the gear change. These sensors can be arranged in the form of separate sensors or also in the form of a construction unit. These sensors are advantageously potentiometers, Hall sensors, incremental sensors or other sensors for the detection of a

displacement section.

  Likewise, it is appropriate that the sensor serving to detect the gear change operation of the transmission is a sensor which detects an actuation of an element for the actuation of the transmission, such as a gear shift lever. This sensor can be a displacement stroke sensor which detects actuation by referring to the displacement curve of the element.

  actuation, such as a gear shift lever.

  In another exemplary embodiment, this sensor can also be a force sensor which detects the actuating force or a reaction force, that is to say a force acting on the gearshift lever. The sensor can also be a sensor of a quantity proportional to a force, which detects a quantity

proportional to a force.

  It is particularly advantageous that at least one sensor signal is used by the control unit and is placed as a gear change intention signal when an element is actuated to actuate the transmission or produces a such voltage signal

  speed change based on sensor values.

  It is further appropriate that, in order to determine a speed change intention signal, the control unit uses at least the signals from two sensors and produces, for example, a speed change intention signal.

  speed from a difference in these signals if any-

  weighted. It is appropriate that the signals from two sensors are converted into a differential travel signal. It is particularly suitable that one sensor is placed on the switching element of the transmission and the other sensor is placed on the gear shift lever. The displacement or offset or position of the transmission switching elements is controlled using these sensors. We can also detect the

  force, with which they act against another element.

  According to the invention, a blocking of a

  gear change operation is identified by the uni-

  Automatic clutch control tee when at least one of the following conditions is satisfied: - a gear change intention signal is present, which indicates that there is an operation for switching to a new speed; - the travel of movement of a switching element in a switching channel for the speed change has not reached its final position value; - the travel of movement of a switching element in a switching channel for a speed change remains less than a threshold value in the direction of the end position; - the gradient of modification of the displacement path of the switching element in a switching path for the speed change falls below a

threshold value.

  Likewise, it may be advantageous for the control unit to identify or determine the existence of a blocking of a speed change operation when at least one of the following conditions, which are identified on the basis of warning signals. sensors, is satisfied: - a speed change intention signal is present, which indicates that we are in the presence of an operation of shifting to a new speed; Il 7 rV - the signal of the travel of a switching element in a switching channel for the gear change has not reached its final position value; - the signal of the travel of movement of a switching element in a switching channel for a speed change remains below a threshold value in the direction of the end position; - the gradient of modification of the displacement path of the switching element in a switching path for the speed change falls below a

threshold value.

  According to the invention, the end position values can vary from one speed to another

  or in different speed groups or else be individual

  dual different. Likewise, the threshold values can depend on the speed or depend on the speed group. It is particularly advantageous for the control unit to identify a blockage when at least some of the conditions are present during a time interval t which can be predetermined. This time interval t is

  preferably ranges from 0.1 s to 0.5 s.

  It is also appropriate that a blockage is identified only when the vehicle is stationary or the vehicle speed is below a speed limit. It is appropriate that, when the gear change process is blocked, the clutch is engaged up to a value which can be predetermined.

  of a torque that can be transmitted to a clutch.

  It is also appropriate that the value that can

  be predetermined, ie the maximum transmissible torque.

  In another exemplary embodiment, it is appropriate that the value which can be predetermined of the torque is less than the maximum transmissible torque. In another exemplary embodiment, it is appropriate that the value which can be predetermined is a small value in the range less than 25 Nm and preferably less than 10 Nm. It is advantageous that the value of the torque that can be transmitted by the clutch be maintained for at

  minus a holding time which can be predetermined.

  It is advantageous that afterwards the couple that can

  be emitted by the clutch is further reduced.

  It is advantageous that in the case of a blocking of the speed change operation, the clutch is engaged in an impulse manner up to a value which can be predetermined of a torque transmissible by the clutch, and that the value of the torque that can be transmitted by the clutch is further reduced. Likewise, it may be appropriate for this to be repeated, if necessary, for obtaining an impulse command. It can also be advantageous if the clutch torque increases according to a staircase configuration or according to

  steps or step by step in another way.

  It is advantageous that the torque which can be transmitted by the clutch can be kept constant for a period of time which can be predetermined.

  after an increase and / or a reduction in the torque.

  It is also appropriate that the engagement of the clutch or an increase in the torque that can be transmitted by the clutch takes place. according to a function in

ramps as a function of time.

  It is appropriate that the maximum of the impulse clutch torque is variable over time. Likewise it is appropriate that the maximum of the clutch torque

  impulse increases as a function of time.

  After complete engagement of the speed, the procedure passes to a usual control procedure, which allows starting, creeping, - stopping the engine, moving or changing speed. The clutch is opened or closed based on other priorities, after

full speed engagement.

  The invention further relates to a method for controlling an actuation system in a motor vehicle. Other features and advantages of the

  present invention will emerge from the description given

  hereinafter taken with reference to the accompanying drawings, in which: - Figure 1 shows a schematic representation of the device according to the invention; Figure 2 shows a block diagram; - Figure 3 shows a block diagram; - Figures 4a to 4c each show a diagram; and Figure 5 shows a switching slide. Figure 1 shows a schematic representation of a motor vehicle 99 comprising a device for actuating a torque transmission system, such as the clutch 2, a drive motor 1, a transmission 3, a control unit 6, a adjustment member, such as an actuator 5, for controlling at least one torque transmission system or the torque that can be transmitted

by the clutch.

  The drive unit 1, such as for example an internal combustion engine, is connected according to a drive link by means of a clutch 2 located in the drive chain of the vehicle, to a transmission or gearbox 3. The torque of the vehicle, present on the side driven at the drive wheels, is controlled by means of the clutch and by means of the controllable transmissible torque of the clutch. The driven shaft 4 of the transmission is also connected according to a flow of -transmission of force or torque optionally by means of a mechanism, such as a differential, to at least one axle

  downstream motor and / or drive wheels.

  Clutch 2, such as a clutch with

  friction, a magnetic powder clutch or a convertor

  Hydrodynamic torque generator with or without a direct drive clutch is controlled by a device for controlling the torque transmission system. The torque transmission system 2, such as the clutch, can be connected upstream or downstream of the transmission 3 which can be manually switched by the. driver in

the force transmission flow.

  Due to the targeted control of the torque transmission system, the respectively necessary torque can be controlled, and not only the maximum torque that can be transmitted, the nominal torque, which only applies during fractions of the total duration of

vehicle operation.

  The control unit controls the engagement and / or disengagement of the clutch or controls the torque that can be transmitted by the transmission system

of couple.

  The device for actuating the torque transmission system has a means 5 for controlling or adjusting the transmissible torque of the torque transmission system, this means 5 being a mechanically controlled clutch release bearing comprising a clutch release fork or a clutch release lever or a hydraulic system comprising a master cylinder or a receiving cylinder, such as for example a central declutching device. In addition, a hydraulic receiving cylinder can act on a

  declutching source for controlling the declutching stop.

  Similarly, an electric motor control of a clutch release bearing can be provided. Similarly, the actuator can be made 11 '' in the form of an electric motor and drive an output element of the actuator via

of a mechanism.

  The actuator 5 is connected according to a signal transmission link to the central control unit 6, which can be equipped with a central computer unit comprising a processor and a memory, the central unit

  control unit 6 which can be linked for its part,

  ment according to a signal transmission link, to other electronic units such as for example to an electronic unit 30 for the engine, an electronic unit 32 for the transmission and / or an anti-lock system (ABS) 31. As detectors, sensors are available, for example, which are necessary to detect or determine the operating point. As sensors, provision may in particular be made for example of a sensor 7, 7a of the speed of rotation of the engine and / or of the transmission, such as for example a sensor of the speed of rotation of the input of the transmission, as well as a sensor 8 used to detect the position of the accelerator pedal 8a as well as a sensor 9 for detecting the position of the shift lever or the force applied to the shift lever 10, as well as a sensor 11 for detecting a position of a switching element 12 internal to the transmission, such as for example the central switching shaft. The sensor 11 can detect both the movement of movement of switching elements of the transmission within switching channels and / or between switching elements for the speed change. This sensor 11 consists of two individual sensors or can be a sensor for both directions of actuations. In addition, it is possible to use, for example, vehicle speed sensors or tachometers,

Tr i = -

  O10 wheel speed sensors, a throttle angle sensor, inclination, acceleration or speed sensors. The signals from these sensors are processed at least instantaneously by the control unit, and the driver's intention to change speed is identified by the control unit by the fact that the measurement data from the sensor are visually dependent. with respect to time, which is exploited as

  that gear shift intention.

  In vehicles comprising a transmission such as a state-of-the-art staggered gearbox, a control element, such as a gearshift lever, is provided for manual actuation of the gear shift reduction gear of the transmission, which is connected to at least one connecting means or to a unit 13 for linking with switching elements internal to the transmission, such as a central switching shaft, switching bars or switching forks of the transmission. A displacement of the shift lever 10 causes a displacement of the

  switching 12 internal to the transmission.

  In general, a movement clearance is present in the connection between the attachment zone of the gearshift lever 10 and at least one switching element 12 internal to the transmission. In addition, there can be provided inside this transmission in general at least one elastic element 14, which is used for example for damping or decoupling of the oscillations or carrying out the prestressing of the connection unit 13. The one or more elastic elements 14 can be arranged between an actuating element or the actuating zone, such as the gripping zone, of the gearshift lever and the gearshift elements internal to the transmission. In addition, the elastic element or elements 11 can be placed in / on the articulations of the unit.

13.

  The sensors 9, 11 are mounted or articulated on the elements of the connection unit between the actuation zone or the actuation element of the gearshift lever and the switching elements inside the transmission. They detect the position or the displacement of the gearshift lever 10 or of a first element 13a connected to this lever and / or the position or displacement of switching elements 12 internal to the transmission or of a second element 13b connected to these elements. The first element 13a and the second element

  13b can be the element of the linking unit 13.

  The positions detected therefore represent at least one position of the gearshift lever or of the internal switching elements of the transmission. In the case of a manual movement, carried out on the driver's side, of the gearshift lever 10, for example from the first gear to come into the neutral position or differently correspondingly, the gearshift lever 10 is all initially moved, in the context of the possible present play of the gearshift lever and the interaction between the gearshift lever and the transmission. The shifting lever is moved without moving the internal switching elements of the transmission, for example, the central switching shaft on the transmission side or the switching swing arms, the switching rods or the switching forks . If one continues to move the gearshift lever after a first displacement, in the range of the play, there is an extension or a compression for example of a part of the element of

  connection between the actuating element and the action zone-

  gear shift lever and an internal transmission switching element. Such an application of force or dynamic load can cause an elongation or a compression for example of an elastic element located in the connection placed in compression or in traction. This elongation or compression can be carried out due to elasticity at the level of the connection as well as on the basis of characteristics of the material of

special components.

  The elasticities and / or the play in the area between the gearshift lever and the internal switching elements of the transmission, which are present in a manufacturing-related manner, are used in accordance with the idea of the invention, for identifying a driver's shift intention based on the movement of the shift lever. Through

  therefore it is not necessary to use imperative-

  an additional elasticity. This can be advantageous in the case of elastic connections between the gearshift lever and switching elements internal to the transmission. However, it may also be advantageous if, in the case of relatively rigid connections between the actuation zone of the gearshift lever and switching elements internal to the transmission, elements are used.

additional elastic.

  Due to the presence of the sensor (s) 11 for identifying the speed, a system for identifying a gear change intention can be obtained at

using signals from these sensors.

  The sensor 9 essentially detects the movement of the speed change lever in the direction of the switching channels of a speed change switching slide. A switching slide of a conventional transmission which can be manually switched T l - __ ___ is shown in FIG. 5. In this figure, there is shown a slide of a five-speed transmission with reverse gear, this

  not constituting any limitation to generality.

  The invention can also be used in conjunction with other transmissions, for example four-speed or six-speed transmissions. In the case of an articulation of a sensor 9 on the gearshift lever, during which both the switching stroke and the selection stroke are taken into account, in the sensor signal, a reduction can be used correspondingly chosen from the respective articulation devices, such as for example along the selection switching path, so as to produce the switching path or channel signal having a dominant influence on the overall signal. This means that a relative change in the signal of the selection path only causes a small change in the signal, compared to a relatively large change in the signal in the case of a corresponding movement in

the switching channel.

  The sensor 11 essentially detects the movement of at least one switching element 12 internal to the transmission, and in particular the movement in the switching direction is used for identification

  an intention to change gear.

  In addition, the identification of a gear change intention can be executed when the gear shift lever is moved in the selection direction and in such a case the articulation of the sensor of the gear shift lever guarantees correspondingly that the two directions of movement are transformed, with the sensor, into a sensor signal having

a good definition.

  On the basis of the information or signals Tl - u T-YF supplied by at least the sensor 9 or the sensor 11, the control unit 6 calculates the position of the gearshift lever 10 and decides, according to criteria predetermined, if a targeted movement of the shift lever is present, and therefore a

  gear change intention is identified.

  If movement of the shift lever is triggered, for example, by the driver of the motor vehicle, the sensors detect an actuation or displacement force, and the control unit performs a predetermined procedure to determine a shift intention . If a gear change intention is identified, an intention signal

  gear change is produced.

  When one of these processes, such as for example a gear change or the engagement of a gear is considered or evaluated as having been completed, since for example a final position of predetermined speed is identified on the basis of a signal from the sensor as being a gear position engaged, the gear change is considered to be complete and a strategy for engaging a clutch engagement process begins. If the final speed engagement position is not reached, the method according to the invention is implemented.

artwork.

  The control unit acquires or receives signals from sensors 9 and / or 11 and determines, on the basis of these signals, the position or positions of important components and / or forms a difference and / or a differential quotient of positions at l inside the link or path sections between the detected positions and controlled elements, in which case important components are taken into account, in particular components located between an actuation zone of the gearshift lever and internal switching

i 11 - F-

  transmission. If a position, a calculated difference or a calculated differential quotient exceeds by the top or exceeds by the bottom a threshold which can be predetermined, a gear change intention is evaluated as being present and a control unit produces a signal

  gear shift intention.

  FIG. 2 represents a block diagram used to explain the method according to the invention. In block 100, an evaluation is made as to whether a gear change intention signal is present. If this is the case, for example, the actuation of a gearshift lever occurs. The control unit identifies this as described and produces a gear change intention signal. In block 101, a check is made to know whether the distance of a switching element of the transmission, such as for example an internal switching element of the transmission, and the final position when the speed is engaged is greater than a value predetermined threshold, which depends on the speed. In other words, if the value or the signal calculated from the channel corresponding to the neutral is less than a threshold value, the final position is not reached. If this is observed simultaneously in accordance with block 100 and block 101 for a certain period of time t which can be predetermined, in block 102 the clutch is slightly engaged at least for a short interval of time. This engagement has the effect that the input shaft of the transmission turns slightly and that the blockage due to teeth of a group of switches which meet, is removed by sliding these teeth relative to each other and that the gear can be engaged in its final position. Therefore between 101 and 102 is mounted a counter, which checks, before the engagement of the engagement of the clutch, if the conditions of the blocks IT 1Tf

  and 101 are also present long enough.

  FIG. 3 represents a block diagram used to explain the method according to the invention. In block 110

  an assessment is made as to whether a signal of intensity

  gear shifting is present. If this is the case, we are in the presence, for example, of the actuation, for example, of a gearshift lever. The control unit identifies this as described and produces a gear change intention signal. In block 111, a check is made to know whether the gradient of modification of the path of movement of a switching element of the transmission, such as for example a switching element internal to the transmission, is less than a threshold value which can

  be predetermined, which can be a function of speed.

  In other words, if the actuation speed is less than a threshold value, the end position is not reached. Consequently, it is also possible to check whether the end position has been reached or not,

in accordance with block 101.

  If the signals supplied by the blocks 101 and 121 are observed simultaneously during a certain time interval t which can be predetermined, the clutch is engaged and disengaged in an impulse manner in the block 112. This engagement and disengagement of the pulses has the effect that the the input shaft of the transmission turns slightly and that the blockage due to teeth of a group of commutations, which meet, is removed by sliding these teeth one on the other, and the speed can be engaged in its final position. A counter can also be installed between 111 and 112 which checks, before the clutch engagement starts, whether the conditions of blocks 110 and 111 are

  also present long enough.

  Figures 4a to 4c show diagrams

Til -

  representing the control of the torque transmitted by the clutch

  yage, in the case of the presence of a blockage. In these figures, there is shown the torque M which can be transmitted by the clutch, also designated by the expression clutch torque, as a function of time t. This increase may be linear or even may be, in another embodiment, non-linear or else carried out in steps or else with a different slope or according to different steps. Figure 4a shows a uniform increase

  or monotonic of the clutch torque M from the ins-

  both tl, from which a blockage was identified for

the control unit.

  FIG. 4b represents a monotonic uniform increase due to a torque M of the clutch up to a limit value M2 from the instant t2, from which a blockage has been identified by the control unit. The value

  of M2 can be chosen according to the speed of engagement-

  vehicle speed. After the expiration of a holding time interval Dt, the clutch torque M can be reduced again. The value of the clutch torque M may be low so that, when the clutch is at least slightly closed, the input shaft

  of the transmission turns at least only slightly.

  FIG. 4c globally represents an impulse behavior of the clutch with a uniform or monotonous rise in the torque M of the clutch to a limit value M3 from time t3, from which a blockage has been identified by l 'control unit. The value of M3 can be chosen according to the speed

  or depending on the speed of the vehicle.

  During the holding time, the torque M remains constant.

  After the expiration of a time interval Dt extending from t4 to t6, the clutch torque M is again reduced to t6, the value of the reduced clutch torque Ir -T1 _ being able to take the value zero or may take a low value other than zero. During another holding time interval up to t7, the

  clutch torque remains constant again.

  Then the control process can be repeated from t3 to t7, in which case the amplitude, i.e. the value

  clutch torque can be changed.

  The value of the clutch torque M, M2 to M5 may be low so that, when the clutch is at least slightly closed, the input shaft of the

  transmission rotates at least only slightly.

  FIG. 5 represents a switching slide 200 of a transmission comprising five forward speeds and a reverse speed R, and a distinction must be made between switching channels 201, 202 and 203 and a selection channel 204. The end positions 210 to 215 represent the position of a switching element of the transmission, such as for example a switching fork or a central switching shaft, when the corresponding speed is engaged. We can

  also use other switching slides.

  It is advantageous that the dependence on the speed is used in such a way that the method according to the invention is carried out at least in the case of non-synchronized speeds, as well as in the case of a

  reverse speed R not synchronized.

  The references 220 to 225 designate threshold values, which are obtained approximately when a blocking

  appears when engaging a gear.

  Furthermore, it is particularly suitable that the limit values or threshold values or the holding times or other important parameters relating to the service life of the vehicle can be adapted and therefore be modifiable. These adaptable parameters can be stored in a memory in

the control unit.

  The invention is not limited to the embodiments described above and on the contrary

  numerous changes and modifications can be produced5 without departing from the scope of the invention.

I --r -

Claims (25)

  1. Motor vehicle comprising a device for the automated actuation of a clutch, comprising an actuator and an electronic control unit, a transmission provided with an element for actuating this transmission, in which a control unit controls the actuation for starting, during a gear change and when stopping, and in which at least one sensor is provided which detects the engaged speed of the transmission and / or a gear change process, characterized in that during the gearshift process is blocked, the clutch is engaged at least partially. 2. Motor vehicle according to claim 1, characterized in that the sensor used to detect the engaged speed of the transmission is or comprises a sensor, which detects the travel of movement of a switching element in a switching channel for the gear switch.   3. Motor vehicle according to claim 1, characterized in that the sensor for detecting the engaged speed of the transmission is or comprises a sensor, which detects the displacement travel of a switching element between switching channels or the long   a selection channel for the change of speed.   4. Motor vehicle according to claim 1,   characterized in that the sensor used to detect the operation   transmission shift ration is a sensor that detects an actuation of an element for actuating the transmission, such as a lever gear switch.   5. Motor vehicle according to any one of   Claims 2 to 4, characterized in that at least one   sensor signal is used by the control unit and is used as a gear change intention signal when an element is actuated to activate the transmission or produces such a gear change voltage signal based on sensor values. 6. Motor vehicle according to any one of   Claims 2 to 5, characterized in that at least one   of sensors is a displacement sensor.   7. Motor vehicle according to any one of   Claims 2 to 5, characterized in that at least one   sensor is a force sensor or a sensor of a   quantity proportional to a force.   8. Motor vehicle according to any one of   Claims 2 to 5, characterized in that at least one   of sensors is an incremental displacement sensor.   9. Motor vehicle according to any one of   Claims 2 to 5, characterized in that the   minus the signals from two sensors for determining   a gear change intention signal.   10. Motor vehicle according to claim 10, characterized in that the two signals from the two sensors are converted into a differential displacement signal. 11. Motor vehicle according to any one   claims 1 to 10, characterized in that   identifies a blocking of a speed change operation when at least one of the following conditions is satisfied: - a speed change intention signal is present, which indicates that there is a speed change operation shift to a new speed; - the travel of movement of a switching element in a switching channel for the speed change has not reached its final position value; the travel of movement of a switching element in a switching channel for a speed change remains less than a threshold value in the direction of the end position; - the gradient of modification of the displacement path of the switching element in a switching path for the speed change falls below a threshold value.   12. Motor vehicle according to any one   of claims 1 to 11, characterized in that   identifies a blocking of a switching process when   that at least one of the following conditions, which are identified from sensor signals, is satisfied: - a gear change intention signal is present, which indicates that there is an operation of shift to a new speed; - the signal of the travel of a switching element in a switching channel for the speed change has not reached its end position value; the signal of the travel of movement of a switching element in a switching channel for a gear change remains below a threshold value in the direction of the end position; - the gradient of modification of the displacement path of the switching element in a switching path for the speed change falls below a threshold value.   13. Motor vehicle according to one or the other   claims 11 and 12, characterized in that a   blockage is identified when at least some of the conditions are present during a time interval t can be predetermined.   14. Motor vehicle according to any one   of claims 1 to 13, characterized in that a blocking   is identified only when the vehicle is stationary or the vehicle speed is less than a value speed limit.   15. Motor vehicle according to claim 1,   characterized in that in the event of a blockage of the operation-   gear change, the clutch is engaged up to a predetermined value of a torque   can be transmitted by the clutch.   16. Motor vehicle according to claim, characterized in that the value can be   predetermined is the maximum transmissible torque.   17. Motor vehicle according to claim, characterized in that the value can be   predetermined is less than the maximum torque transmitted-   sible. 18. Motor vehicle according to claim, characterized in that the value which can be predetermined is a low value in the range   less than 25 Nm and preferably less than 10 Nm.   19. Motor vehicle according to any one   claims 15 to 18, characterized in that the value   is maintained for at least a maintenance period which may be predetermined.   20. Motor vehicle according to claim 19, characterized in that then the torque which can be   transmitted by the clutch is again reduced.   21. Motor vehicle according to claim 1,   characterized in that in the event of a blockage of the operation-   gear change, the clutch is engaged in an impulse manner up to a predetermined value of a torque transmissible by the clutch, and that the value of the torque can be   transmitted by the clutch is again reduced.   22. Motor vehicle according to claim 21, characterized in that the maximum of the clutch torque   impulse is variable over time. 1 ^ T '   23. Motor vehicle according to claim 21, characterized in that the maximum of the impulse torque   clutch increases with time.   24. Motor vehicle according to one of   previous claims, characterized in that the torque   which can be transmitted by the clutch can be kept constant for a time interval which can be predetermined after an increase and / or a reduction in the torque. 25. Motor vehicle according to any one of   claims 1 to 23, characterized in that the enclosure   clutch or an increase in the torque that can be transmitted by the clutch takes place according to a   ramp function versus time.