Abstract: A control device for an automatic transmission having a torque converter with a lock-up clutch provided between an engine and the automatic transmission, and a lock-up control device for controlling an engaged condition of the lock-up clutch.

Abstract: A transmission control apparatus is provided for a straddle-type vehicle that has a clutch and a transmission with a dog clutch having a first gear and a second gear. The transmission control apparatus includes a clutch actuator configured to engage and disengage the clutch. A transmission actuator is configured to change a gear of the transmission. An input device is configured to generate a gear change command. A first sensor is configured to determine whether the vehicle is in a standstill condition. A controller is operatively connected to the clutch actuator, the transmission actuator and the first sensor. The controller is configured to, in response to the gear change command, set the clutch position between a partially engaged position and a completely released position if the vehicle is standing still as determined by the first sensor.

Abstract: A clutch control apparatus for a power transmission system including an input rotating member and an output rotating member. The clutch control apparatus includes a friction clutch, and a control unit. The control unit sets a first desired clutch torque setting in accordance with a clutch slip indicator; sets a second desired clutch torque setting to an amount of torque input from the input rotating member to the friction clutch; controls the clutch torque to be the first desired clutch torque setting during a starting stage of the friction clutch; controls the clutch torque to be the second desired clutch torque setting during a steady-state stage of the friction clutch; and controls the clutch torque to gradually change from the first desired clutch torque setting to the second desired clutch torque setting during a transition stage between the starting stage and the steady-state stage.

Abstract: A clutch control apparatus for a hybrid vehicle (1) having an engine (2) and a motor (3) as power sources, and an output shaft (13a). The clutch control apparatus includes a clutch device (12) and a clutch control device (19) operatively connected to the clutch device (12) for controlling the engagement degree of the clutch device (12) when the driving mode of the vehicle is alternately switched between an engine cruise mode and a motor cruise mode. The clutch control device (19) is adapted to execute a clutch relaxation control operation which includes an engagement decreasing control operation and a subsequent engagement recovery control operation, and is further adapted to execute an engagement increasing control operation in which the engagement degree of the clutch device (12) is forced to increase when the revolution rate of the engine (2) falls below a predetermined value.

Abstract: A method and system for regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter includes determining a non-linear slip profile based on vehicle operating parameters, calculating an actual TCC slip, calculating a TCC ramp pressure based on the non-linear slip profile and the actual TCC slip and regulating a TCC engagement pressure based on the TCC ramp pressure.

Abstract: A starting device has a first friction element, a second friction element, and a control unit controlling them to change their power transmission states. The friction elements are arranged between an engine and wheels. The control unit controls the first element to produce creep torque by its slippage for creep of a motor vehicle. It includes a slip state judging means judging an excessive slip state of the first element in which it deviates from a permissible slip state, and a slip state shifting means shifting the slip state of the first element and a power transmission state of the second element so as to perform a protect control in which a slip amount of the first element decreases and the second element slips, in a case where the slip state judging means judges the excessive slip state.

Abstract: A method for the advance determination of an overload of an automatically actuated clutch of a vehicle during a slippage phase and to prevent the overload. The method determines the energy introduced into the clutch during a predetermined first time span of the slippage phase and/or acquires the current temperature of the clutch and, on the basis of the anticipated second time span of the slippage phase, determines the anticipated energy introduction into the clutch and/or the anticipated clutch temperature and, as a function of the anticipated energy introduction and/or the anticipated clutch temperature, takes measures to prevent the overload.

Abstract: A system for controlling a torque converter clutch in a vehicle powertrain includes a controller having an input for receiving powertrain operating parameter information. The controller is configured to determine a torque converter speed ratio based on the powertrain operating parameter information and to compare the speed ratio to a specified speed ratio limit. The controller is further configured to determine a target torque converter slip when the speed ratio exceeds or meets or exceeds the specified speed ratio limit; to compare the target slip with a desired slip value based on an vehicle noise, vibration or harshness (NVH) limit; and to control torque transmission of the torque converter clutch based on comparison of the target slip and the desired slip value. A method for controlling a torque converter clutch is also provided.

Abstract: A method of controlling at least a fifth characteristic operating value of a motor vehicle power train includes the step of performing an emergency adaptation of at least one of the stored clutch-disengagement thresholds during an operating phase of the motor vehicle, if predetermined third conditions are present. The method also includes the step of performing a nonemergency adaptation of at least one of the stored clutch-disengagement thresholds at the end of the operating phase if predetermined fourth conditions are present.

Abstract: A clutch control apparatus is provided for a hybrid vehicle having at least two different power sources and a clutch disposed between the power sources and the drive wheels arranged to vary a transmission torque capacity. A separate clutch input and output speed sensing device senses the actual clutch input and output speeds respectively. A controller is configured to calculate a target vehicle driving torque according to a driver's operation and the vehicle running condition.

Abstract: The magnitude of torque which can be transmitted by a bypass clutch between the housing and the turbine of a torque converter between a prime mover, such as an engine, and an automatic transmission in the power train of a motor vehicle is selectively regulatable by a computerized regulating unit. The regulation involves the transmission of torque by the clutch in dependency upon the magnitude of the torque being transmitted by the output element of the engine and ascertaining as well as adaptively applying to the clutch a variable force so that the clutch can transmit a predetermined torque. This entails automatic selection of a minimum slip between a torque receiving and a torque transmitting part of the power train. Compensation, particularly long-range compensation, is carried out for the existence of possible differences between the predetermined and actual torques being transmitted by the clutch.

Abstract: A method is provided for shifting a powershift transmission in a vehicle having an electronic engine control unit and an electronic transmission control unit. The method rapidly reduces off-going clutch pressure to a pressure which is slightly higher than a Predicted Off Slip Pressure, and rapidly increases on-coming clutch pressure P-on to a pressure that is slightly lower than a Predicted On Slip Pressure. Then, the method includes gradually decreasing P-off and gradually increasing P-on until slipping of the off-going clutch is detected, and gradually and more slowly decreasing P-off and gradually more slowly increasing P-on until the oncoming clutch begins to carry torque previously carried by the off-going clutch. Finally, the method includes more rapidly decreasing P-off to reservoir pressure, and more rapidly increasing P-on to a full on pressure.

Abstract: A method is provided wherein when an auxiliary device is being powered by the PTO driveline the PTO clutch is periodically slowly ramped down in pressure until slippage is detected in the clutch. Slippage is determined by monitoring the shaft speed into the clutch as well as the shaft speed downstream of the clutch. By determining the commanded pressure where slippage occurred, the equivalent engine power that is going to the auxiliary function is calculated. With this information, the proportion of the engine load signal that is going to the auxiliary function versus the drive wheels is determined. After slip is detected in the PTO clutch, pressure is ramped back up in the clutch so as to minimize the amount of slippage.

Abstract: In automatic shift control apparatus and method for a manual transmission, at least one clutch is interposed between an engine and the manual transmission and a controller performs a feedback control for an engagement force of the clutch after a gear shift for the manual transmission is ended in such a manner that an input revolution speed of the clutch is directed toward another revolution speed thereof after the gear shift occurs at a predetermined time variation rate, the controller setting mutually different feedback control gains in a variation region of the input revolution speed of the clutch in which the input revolution speed of the clutch is directed toward the other revolution speed after the gear shift occurs and in a convergence region of the input revolution speed in which the input revolution speed of the clutch has reached to the other revolution speed after the gear shift occurs.

Abstract: The upshift control method of an automatic transmission for vehicles includes determining whether a start condition of a damper clutch control operation is satisfied during an upshift under a power-off. The method also includes executing the damper clutch control operation depending on predetermined control intervals and control duties in order to enhance a shift feel, the predetermined control intervals and control duties being set on the basis of a shift speed, a turbine RPM, and a transmission oil temperature, when the start condition of the damper clutch operation control is satisfied. The method further includes executing a fuel cut control after a damper clutch is engaged by the damper clutch control operation.

Abstract: In an automatic transmission including a forward clutch and a lockup clutch of a torque converter which are provided on a driving-power transmitting path between an engine and a driving wheel, a vehicle driving condition is classified into a plurality of regions and an associated slip control between the forward clutch and the lockup clutch is executed. Accordingly, both of improvements of gas mileage and drivability can be attained at a high level.

Abstract: A method for controlling an engine coupled to a transmission is described. The method is especially suited for a transmission having at least one gear in which an over-running clutch is present. The invention describes a method for adjusting an engine operating parameter to maintain transmission input speed at or below a synchronous transmission input speed when the transmission is in the gear with the over-running clutch. The synchronous transmission input speed is based on transmission state and transmission output speed. Alternatively, vehicle speed can be used in place of transmission output speed.

Abstract: There is provided a start clutch control system for a vehicle, including a start clutch disposed between an engine and a transmission in the vehicle, a detection unit that detects vehicle running conditions including at least a vehicle speed, and a control unit that controls engagement and disengagement of the start clutch according to the detected vehicle running conditions. The control unit has a target torque determining section to determine a target torque transmitted by the start clutch with reference to the vehicle running conditions, a torque transmission characteristic setting section to set a transmission characteristic of the target torque differently depending on the vehicle speed, a phase compensating section to make a phase compensation for the torque transmission characteristic based on actual and target mathematical models of the vehicle, and a clutch control section to control the start clutch according to the phase-compensated torque transmission characteristic.

Abstract: A method, a device, and use thereof for operating a motor vehicle having a drive motor and a transmission in the drive train are proposed.

Abstract: Provided is a method for controlling a magnet type fan clutch, by which method engine performance, fuel efficiency, engine life, vehicle acceleration capability and other properties of a magnet type fan clutch can be further improved and its fan noise can be further reduced. This method is adopted for controlling a magnet type fan clutch which includes a magnet coupling, an electromagnetic clutch combined with the magnet coupling to control the on/off switching of the magnet coupling, and a fan attached to the magnet coupling. The control method is characterized in that the electromagnetic clutch is turned on or off based on at least one signal of temperatures of radiator coolant, engine oil and transmission oil, a vehicle speed, a rotational speed of an engine, compressor pressure of an air conditioner, and an on/off signal of the air conditioner, etc., so as to control the rotation of the fan.

Abstract: The present invention aims at providing an apparatus and method for controlling a clutch of a mechanical automatic transmission which enables smoother start of movement. To this end, range setting means sets an engine speed range in which engine output torque achieved at an accelerator position detected by accelerator position detection means defines a predetermined range including the maximum value. Clutch control means throws in a clutch while controlling a connected state of a clutch such that the engine speed detected by engine speed detection falls within the engine speed range set by the range setting means.

Abstract: A method for launching an automatic vehicle transmission utilizing dual clutches in place of a torque converter avoids clutch overheating, sudden launch or roll-back by placing a clutch in a slip mode only after the vehicle's brakes have been actuated and fully disengaging the clutch upon over-heating detection. When launch is initiated, a first gear engaged and the brakes are released, the associated clutch is fully engaged to avoid overheating.

Abstract: A method and device for operating a clutch between an internal combustion engine and at least one driven wheel of a vehicle, a torque being transmitted between the internal combustion engine and the driven wheel by pressing the clutch together via an application force or an application pressure, and the application force or the application pressure being controlled or regulated as a function of the temperature of the clutch.

Abstract: A control strategy is provided for controlling engagement of a clutch during vehicle launch. A feed-back input command and a feed-forward input command are utilized and summed to determine a clutch control command. The feed back input command uses a reference slip profile having a low speed portion and a high speed portion. In the low speed portion, the slip is a function of engine speed. In the high speed portion, the slip is a function of transmission output speed or vehicle speed.

Abstract: A method for automatically adjusting slip in an automatic friction clutch arranged between an engine and a gearbox of a motor vehicle. The clutch has a clutch-adjusting positioning drive which adjusts the clutch to a position which is defined by a position set-point signal. The clutch input speed and the clutch output speed are detected using speed sensors and a position set-point signal is produced according to the difference of the speeds (slip speed). The slip speed is equal to a predefined set slip value and is used as a control variable for the transmitted clutch torque. An engine torque is used as a control variable for the clutch instead of the clutch torque or as a complement thereto.

Abstract: An automotive vehicle driveline includes an internal combustion engine for transmitting input torque to a hydraulically-actuated input clutch, and having a throttle controlled by a displaceable accelerator pedal. A transmission produces multiple gear ratios between the clutch and an output. A method for controlling operation of the clutch includes determining a magnitude of clutch pressure that would produce a torque capacity of the input clutch equal to the current magnitude of input torque; if no transient condition occurs, pressurizing the clutch at a magnitude of pressure that produces a predetermined slip of the input clutch at the current magnitude of input torque; and if a transient condition occurs, holding and/or reducing the determined input clutch pressure such that slip occurs at the input clutch.

Abstract: Friction clutches 203, 204 and engaging clutches 19, 20, 21 are arranged between an input shaft and an output shaft of a gear type transmission having a plurality of gear trains. A power train unit 100 controls an output shaft torque and an input rotation speed of the transmission during changing speed by estimating or detecting input a torque to the transmission, and detecting an output rotation speed of the transmission, and setting a target shift torque during shifting gear, and setting a command value to the friction clutches 203 and 204 from the target shift torque and the input torque.

Abstract: There is provided a control system for a vehicle, which is capable of increasing the service life of a transmission belt while preventing slippage thereof, and at the same time improving fuel economy and drivability. The control system for a vehicle sets a transmission transfer torque to be transmitted from a drive pulley of a continuously variable transmission to a driven pulley of the same, and a clutch transfer torque to be transferred by a clutch. When it is determined that the vehicle is traveling on a bad road, the clutch transfer torque is reduced, and the transmission transfer torque is set to a larger value as the clutch transfer torque is larger.

Abstract: A method for controlling an engine coupled to a transmission is described. The method is especially suited for a transmission having at least one gear in which an over-running clutch is present. The invention describes a method for adjusting an engine operating parameter to maintain transmission input speed at or below a synchronous transmission input speed when the transmission is in the gear with the over-running clutch. The synchronous transmission input speed is based on transmission state and transmission output speed. Alternatively, vehicle speed can be used in place of transmission output speed.

Abstract: The method for control of an automated starting element such as a starting clutch or starting brake according to the thermal load of the starting clutch, which method regulates the control parameters according to a determined driving state, a tractional resistance and/or an actual clutch temperature, has one control module (1) which, below a critical control parameter limit starting from which an increased thermal load or an increased wear appears, reduced the friction work of the starting element. The reduction takes place by a reduction of the slipping time by regulating the slip in the starting element and/or by influencing at least one of the parameters (?, proportional/integral or differential parts, M_Control, p_Gradient or n_Nominal), the number of steps simultaneously used for reducing the friction work increasing with the temperature of the clutch.

Abstract: An automatic-clutch control system of a transmission for a vehicle is arranged to calculate a deceleration of the vehicle when shifting is not being executed, when an automatic shift mode is being selected, when an idle switch is set at ON state, and when a brake switch is set at OFF state, and when the vehicle is being decelerated. Further, the automatic-clutch control system decreases an engagement force of the automatic clutch according to an increase of the deceleration and a decrease of a vehicle speed to vary the engagement state.

Abstract: In a differential limiting torque control section, a target differential rotation speed between front and rear drive shafts is established according to a dial position inputted by a driver of a variable dial. Further, an actual differential rotation speed between front and rear drive shafts is calculated and a deviation between the target differential rotation speed and the actual differential rotation speed is calculated. Based on the deviation, a first differential limiting torque and based on a dial position of a variable dial a second differential limiting torque are calculated. Further, a third differential limiting torque is calculated based on the dial position and a throttle opening angle. A final differential limiting torque between front and rear drive shafts is obtained by summing up these first, second and third differential limiting torques.

Abstract: A torque converter (1) comprises a pump impeller (1a) and turbine runner (1b) which transmit a torque via a fluid, and a lockup clutch (2) which engage the pump impeller (1a) and turbine runner (1b) according to an oil pressure. The pump impeller (1a) is connected to an engine (21), and the turbine runner (1b) is connected to an automatic transmission (23). An oil pressure control valve (3) supplies oil pressure to the lockup clutch (2) according to a signal from the controller (5). The controller (5) calculates a rotation speed increase rate of the turbine runner (1b) (S1), and controls the oil pressure of the oil pressure control valve (3) under a pressure increase rate which increases as the rotation speed increase rate (S10) increases, thereby preventing rotation speed fluctuations of the engine (23) accompanying lockup of the lockup clutch (2).

Abstract: In order to control slip amount of a disengagement side engagement device at the time of a gear shift operation, a target value Nr for rotational speed of an input shaft of an automatic transmission is calculated inside an input shaft speed target value calculating block. Slip control of the disengagement side engagement device is then carried out by controlling engine torque using an engine torque control amount obtained from a engine torque control amount estimation block and the clutch slip amount compensation value calculating section to cause rotation speed Nt of the input shaft to follow the target value Nr. In this way, responsiveness and precision of slip control of the disengagement side engagement device at the time of gear shift operation are improved, and it is possible to improve gear shift shock and to carry out a gear shift operation in a short period of time.

Abstract: A method for controlling the safety mode of a four-wheel drive to control the magnetic clutch at a safety mode duty to reduce overload for a predetermined period of time when the slip of the magnetic clutch is greater than an allowable slip, despite controlling the magnetic clutch at its maximum duty.

Abstract: In a vehicle having a hydraulic power transmitting device equipped with a lock-up clutch on an output side of the engine, a control apparatus for controlling the lock-up clutch is provided which includes a lock-up clutch control unit that places the lock-up clutch in a slipping state when the vehicle is started so that torque received from the engine is transmitted to a later-stage transmission via the lock-up clutch as well as the hydraulic power transmitting device.

Abstract: A control apparatus for a lock-up clutch of a vehicle having a hydraulic torque transfer device equipped with the lock-up clutch between a power source and an automatic transmission is provided for controlling a hydraulic pressure of hydraulic oil supplied to the lock-up clutch when the clutch is in a slip region. The control apparatus determines whether an oil temperature of the hydraulic oil is lower than a predetermined temperature, calculates a change in input torque of the lock-up clutch, and determines whether the change in the input torque is larger than a predetermined value. When it is determined that the oil temperature of the hydraulic oil is lower than the predetermined temperature and that the change in the input torque is larger than the predetermined value, the control apparatus changes the hydraulic pressure of the hydraulic oil supplied to the lock-up clutch to a predetermined pressure for a predetermined length of time.

Abstract: In a lockup control system of an automatic transmission with a lockup torque converter, a controller pre-stores a predetermined lockup control map including at least a predetermined coast slip lockup area, within which the system executes a slip lockup control mode under the vehicle's coasting condition, so that a speed difference between input and output speeds of the torque converter is brought closer to a predetermined value. The controller determines whether a first transition from the vehicle's driving condition to the predetermined coast slip lockup area occurs in a release mode of the lockup clutch or a second transition from the vehicle's coasting condition to the predetermined coast slip lockup area occurs in the release mode. When the first transition occurs, the lockup clutch is conditioned in the slip lockup control mode. When the second transition occurs, the lockup clutch is conditioned in the release mode.

Abstract: A method for reducing oscillation in an automotive transmission system includes detecting a tip-out of an accelerator pedal position. Responsive to the detected tip-out, a pressure command is adjusted for a selected range clutch within the transmission system so as to reduce the pressure of the selected range clutch from a normal pressure level to a low pressure level, thereby producing a desired gear train slip in the transmission system. Then, the pressure command of the selected range clutch is re-adjusted after a determined period of time at the low pressure level so as to increase the pressure of the selected range clutch from the low pressure level, and thereby eliminating the gear train slip.

Abstract: A method for altering the coupling torque of a coupling in the drive train of a vehicle with an automatic gearbox and/or automatic coupling in a creep drive mode of a vehicle. According to the invention, the coupling torque is altered according to at least one variable, the parameter of the vehicle describing the creep drive mode thereof.

Abstract: A starting clutch control device controls such that the transmission torque capacity of a starting clutch (clutch torque) becomes a value required to transmit a torque equal to an engine absorption torque at the time of power-off running. A control of gradually increasing a clutch torque is carried out with a delay after an accelerator pedal is depressed during power-off running, to thereby prevent the occurrence of surging vibrations when an accelerator pedal is abruptly depressed during power-off running.

Abstract: A control device for a lock-up mechanism arranged parallel with a hydraulic type torque transmitting mechanism that transmits rotatory power of a pump impeller connected with an output shaft of an engine to a turbine impeller connected with a wheel side element. The lock-up mechanism controls a slip value between the rotational speeds of the pump and turbine impellers in response to supplied hydraulic pressure. The control device calculates a target slip value, detects an actual slip value based on the rotational speed difference of the pump and turbine impellers, sets an intermediate slip value between the actual and target slip values, controls the hydraulic pressure to the lock-up mechanism so that the actual and intermediate slip values coincide, and reduces the intermediate slip value to a renewed value closer to the target slip value than the intermediate slip value when the actual slip value reaches the intermediate slip value.

Abstract: A lock-up control device for a lock-up torque converter of an automatic transmission is provided which starts measuring an elapsed time when the throttle opening exceeds a first predetermined value due to depression of an accelerator pedal during lock-up clutch slip control. When the throttle opening exceeds a second predetermined value due to sudden depression of the accelerator pedal prior to the elapse of a determination time, a transmission controller terminates the lock-up clutch slip control. After a rapid increase, the slip amount starts decreasing upon termination of the lock-up clutch slip control. Therefore, the temperature of a facing stops rising when the lock-up clutch slip control is terminated, and this improves the durability of the facing. The lock-up clutch slip control is re-started when the throttle opening is reduced to a predetermined value, and this maintains the excellent fuel economy performance.

Abstract: A control apparatus for controlling a shift operation in an automatic transmission includes a disengaging side controlling means for performing a feedback control so as to substantially match a slip amount calculated by a slip amount calculating means with a target slip amount calculated by a target slip amount calculating means when the calculated slip amount is judged to be in excess of the predetermined threshold value by a judging means. The target slip amount varies from a predetermined threshold value to a predetermined target value drawing an ideal trace for restraining a shift shock and is maintained at the predetermined target value. The control apparatus further includes an engaging side controlling means for increasing a torque to be transmitted to an on-coming friction engagement element in association with commencement of the feedback control.

Abstract: A procedure for the control and regulation of a clutch of an automatic stepless transmission for a motor vehicle in which an electronic control device, via a first or second regulation circuit, determines the behavior of the clutch during three driving conditions and wherein a stepless gear ratio change is carried out from a first into a second gear ratio. In accord with the invention, for the control and the regulation of the clutch during the first driving condition, the first regulation circuit is employed, the size of the regulation thereof being equivalent to the actual value of the motor speed of rotation (n_MOT_IST). During the second driving condition, a second regulating circuit is employed, the size of the regulation thereof being equivalent to the actual value of a difference in speeds of rotation (dnK_IST) of the clutch and during the third driving condition, the clutch is subjected to a controlled pressure value dependent upon various value influences.

Abstract: A PTO clutch of an agricultural vehicle connects an input driveline to an output driveline for coupling to an attached implement. A method and system for controlling the PTO clutch includes sensors for sensing rotational speeds on both sides of the clutch. Clutch slip is determined from the sensed speeds. A controller receives an actual slip signal and a desired slip signal and controls pressure in the clutch to maintain a constant desired clutch slip in order to avoid overload conditions. The torque transmitted by the clutch is determined as a function of the slip in the clutch and the clutch pressure, and a signal representing this torque is displayed to an operator.

Abstract: A vehicle control device for front and rear wheel drive vehicles, which have one wheel pair driven with an engine and the other pair driven with an electrical motor, and a torque converter with a lock-up mechanism controlling the engagement amount, has a lock-up control means changing the target slip amount to be set in accordance with driving conditions, a motor drive power setting means which sets the drive power distribution ratio of the motor and a compensation means which compensates the target slip amount according to the drive power distribution ratio set by the motor drive power setting means. The control device enables the setting of the optimum slip ratio of the torque converter to improve the fuel consumption, avoiding problems associated with: noise and vibration during the motor assisting.

Abstract: When a deceleration slip executing minimum gear stage is not established in a state of continuously executing a deceleration slip control at a target slip amount, it is judged whether or not an input shaft rotational speed of a transmission becomes a down shift judging rotational speed. When it becomes equal to or less than a predetermined down shift judging rotational speed, a down shift is executed, and a clutch pressure is controlled such that an engine rotational speed becomes a target engine rotational speed.

Abstract: A method of controlling and/or regulating the slip of a clutch, for example, a clutch of a transmission, for example, a CVT transmission, is provided, the clutch including a driving element and an output element. The method measures at least one driving rotational speed and at least one output rotational speed for the controlling and/or regulating of the slip of the clutch, at least one driving rotational speed being measured when the clutch is closed, and at least one output rotational speed being measured when the clutch is closed; and the method determines a corrected driving rotational speed and/or a corrected output rotational speed for considering errors in the measured driving rotational speeds and in the measured output rotational speeds, by considering the at least one driving rotational speed measured when the clutch is closed and the at least one output rotational speed measured when the clutch is closed.

Abstract: A method for operating a clutch (10), whose clutch slip (s) is adjusted to a setpoint value (s0) with the aid of a manipulated variable, should allow a clutch to be controlled in a particularly reliable and stable manner. To this end, the present invention provides for a slip value only being permitted to be a setpoint value (s0), when the derivative of the friction coefficient/slip characteristic at this slip value exceeds a specifiable limiting value. In particular, the setpoint value (s0) is selected as a function of a number of operating parameters, inside a range of permissible setpoint values (s0); the slip value, at which the derivative of the friction coefficient/slip characteristic falls below a specifiable limiting value, being selected as an upper limit (G) of the range of permissible setpoint values (s0).