Abstract: A vehicle speed estimator includes a unit that selects a minimum rotation speed among rotation speeds of wheels detected by a rotation speed detector and calculates a reference wheel speed of a construction vehicle at every predetermined time. The unit includes: a variable filter processor that performs a low-pass filter processing to the minimum rotation speed, the variable filter processor having a variable time constant; and a time constant changer that changes the time constant of the variable filter processor in accordance with travel conditions of the construction vehicle.

Abstract: A control device for controlling an engagement state of a lock-up clutch is provided. A plurality of target slip ratio maps include a normal slip ratio map having a characteristic line of a target slip ratio defined in accordance with an engine load at a normal vehicle running condition and a modified slip ratio map having a characteristic line of the target slip ratio to become a facing calorific value lower than a facing calorific value corresponding to the slip ratio retrieved from the normal slip ratio map. In the case where an estimate value of the facing temperature continues to exceed first threshold temperature for more than predetermined time when to carry out slip control using the normal slip ratio map, control to switch the target slip ratio map from the normal slip ratio map to the modified slip ratio map is carried out.

Abstract: A powertrain system includes an engine control module that generates a negative torque transition signal based on a pending negative torque event of an engine. A transmission control module receives the negative torque transition signal from the engine control module. The transmission control module increases a slip speed of a torque converter clutch in preparation for the pending negative torque event by adjusting pressure in the torque converter clutch prior to the pending negative torque event. The transmission control module decreases the slip speed in the torque converter clutch based on completion of a transition at least one of to the pending negative torque event and from the pending negative torque event.

Abstract: A method of operating a torque converter clutch in an engine start-stop vehicle improves launch after an auto stop event. During the autostop event, hydraulic fluid is supplied to the torque converter clutch operator through one or more solenoid valves by an auxiliary electric pump. When the prime mover is started at the conclusion of the autostop event, the torque converter clutch is thus locked, assuring rapid and sufficient torque transfer through the torque converter to the transmission and improved acceleration during vehicle launch. As the vehicle accelerates, the hydraulic pressure in the clutch operator is reduced and slip through the clutch increased to achieve a smooth launch and return to conventional torque converter operation.

Abstract: A method for controlling a clutch unit for a drive train of a motor vehicle wherein the temperature in the friction clutch is ascertained and a characteristic curve of the friction clutch is adapted as a function of the ascertained temperature.

Abstract: A control device for a vehicular power transmitting system including a torque converter (6) having a pump impeller (6p), a turbine wheel (6t), a stator wheel (6s) rotatably disposed between the turbine wheel and the pump impeller, and a lock-up clutch (L/U) includes a capacity coefficient control unit (126) that controls a capacity coefficient of the torque converter by controlling rotation of the stator wheel, and the capacity coefficient control unit increases the capacity coefficient of the torque converter based on an amount of heat generated during slip control of the lock-up clutch.

Abstract: A method is proposed for controlling a through-connection clutch of a vehicle, in which an interlocking portion of the clutch is opened when the drive-train is virtually free from torque, a shifting operation is then carried out, and after the shifting operation the clutch is closed again. According to the invention, the torque transmitted by the interlocked connection in the clutch is influenced by controlling the motor in order to produce a torque-free condition at the interlocked connection in the clutch, in such manner that the interlocked connection is pre-stressed before the torque-free condition has been reached and separated immediately only when the torque-free condition is reached.

Abstract: An automatic transmission has a transmission control section performing a control so that a transmission ratio defined as input rpm/output rpm of the automatic transmission becomes a target transmission ratio, a slip control section slip-controlling a frictional engagement element in the automatic transmission so that the input rpm becomes a value obtained by multiplying the output rpm by the target transmission ratio also adding a predetermined slip revolution speed; and an abnormality judgment section judging abnormality in the automatic transmission. When the slip-control is not in progress, if an actual transmission ratio is out of a predetermined range of the target transmission ratio, the abnormality judgment section judges that abnormality occurs. When the slip-control is in progress, if a value obtained by correcting the actual transmission ratio on the basis of the slip revolution speed is out of the predetermined range, the abnormality judgment section judges that abnormality occurs.

Abstract: A map is provided that has an unlimited region where a take-off slip-engagement the next time is repeatedly executed indefinitely, a limited region where the take-off slip-engagement the next time is repeatedly executed only once, and a prohibited region where the take-off slip-engagement the next time is prohibited, and has a generated heat amount during the take-off slip-engagement and an elapsed time after the lock-up slip-engagement ends as variables. Therefore, a region in which the take-off slip-engagement the next time had been prohibited because the take-off slip-engagement the next time is unable to be repeatedly executed indefinitely even though it is able to be repeatedly executed only once is made the limited region, so the take-off slip-engagement the next time is allowed to be repeatedly executed only once.

Abstract: A method for controlling actuation of a torque converter clutch includes monitoring a transmission input speed, comparing the monitored transmission input speed to a threshold input speed, and, when the transmission input speed is less than the threshold input speed, controlling an engine speed based upon a desired minimum engine speed. Controlling the engine speed based upon the desired minimum engine speed includes monitoring a minimum engine speed critical parameter, determining the desired minimum engine speed based upon the minimum engine speed critical parameter, comparing the engine speed to the desired minimum engine speed, and controlling actuation of the clutch device based upon a result of the comparing the engine speed to the desired minimum engine speed.

Abstract: A transmission system (14) comprising an input shaft (112); a first clutch (114) configured to selectively couple a first gear (116) to the input shaft (112); an output shaft (126); a second gear (138) engaging with the first gear (116), —and a second clutch (136) configured to couple the second gear (138) to the output shaft (126) when the first gear (116) rotates the second gear (138) faster than the output shaft (126).

Abstract: A method for operating a clutch includes operating the clutch with increased slip during a green phase and operating the clutch with normal slip during a post-green phase. In some example embodiments, increased slip consists of slip speeds greater than 40 revolutions per minute. In an example embodiment, increased slip consists of a slip speed of approximately 50 revolutions per minute.

Abstract: The present invention provides a method for reducing backlash vibrations in a hybrid electric vehicle, in which the backlash vibrations generated between a motor and a driving wheel can be easily reduced by slipping a clutch in an automatic transmission when the direction of a motor driving torque is changed while the hybrid electric vehicle is running in electric vehicle (EV) mode.

Abstract: A method of adapting control of clutches of a double clutch transmission, including: during a shifting process, controlling torque transmittable by an opening clutch and torque transmittable by a closing clutch according to nominal curves; during a shifting process, determining a difference between a nominal value and an actual value; and adapting a nominal curve of at least one of the clutches for a following shifting process by reducing a difference between the nominal value and the actual value.

Abstract: A transmission control device includes a load increase rate computation portion and a transmission control portion. The load increase rate computation portion is configured to compute an increase rate of a load acting on the work vehicle. The transmission control portion is configured to shift a high-speed gear down to a low-speed gear with producing a lock-up state in which a lock-up clutch is engaged when the load increase rate is less than a load increase rate threshold in shifting the high-speed gear down to the low-speed gear, and producing a torque converter state in which the lock-up clutch is disengaged when the load increase rate is equal to or greater than the load increase rate threshold in shifting the high-speed gear down to the low-speed gear.

Abstract: A vehicle includes an engine and transmission. A first rotating clutch engages as an oncoming clutch during a predetermined shift maneuver having a total required clutch energy. A second rotating clutch acts as a holding clutch. A third rotating clutch engages as an additional oncoming clutch during the shift maneuver to share clutch energy with the first rotating clutch. The third rotating clutch, when not engaged, has a zero slip speed relative to the input member. A method includes building a shift table for a transmission design, including identifying slip speed ratios, with respect to the input member, for each clutch, and selecting, from the shift table, a direct drive or other gear state in which three of the rotating clutches are simultaneously operating at a zero slip speed ratio with respect to the input member. The third rotating clutch engages during the shift maneuver.

Abstract: This invention is a lock-up clutch control device for an automatic transmission, comprising lock-up clutch control means for controlling a slip amount of the lock-up clutch to a target slip amount. When a variation rate in a required load of an engine reaches or exceeds a predetermined threshold, the target slip amount is increased at a predetermined increase rate, whereupon the target slip amount, having been increased by target slip amount increasing means, is reduced at a predetermined reduction rate. At this time, the predetermined reduction rate is set to decrease as an operating condition when the variation rate of the required load reaches or exceeds the predetermined threshold approaches an operating condition in which an increase rate of a rotation speed on the automatic transmission side of a torque converter relative to an increase in the required load is low.

Abstract: A clutch of a hydrodynamic torque converter in which the input drive of the hydrodynamic torque converter can be connected to the output drive of the hydrodynamic torque converter. The clutch of the hydrodynamic torque converter is only engaged if a difference between the rotational speeds of the pump and the turbine of the hydrodynamic torque converter is not reached and a predefined distance traveled by the accelerator pedal is exceeded.

Abstract: The invention relates to a method for controlling rotation speed of at least one rotary element in the drive line of a vehicle. A first control model and a second control model are defined. The first control model calculates a permitted slip of at least one of the ground engagement elements of the vehicle at its ground contact point, which ground engagement element is driven via the rotary element. The second control model calculates a torque to said ground engagement element. The result of one of said control models is used for controlling the rotation speed of the rotary element.

Abstract: A method of operating the torque converter lock-up clutch in a power transmission of a working machine comprising at least one hydraulically actuated lifting device. The torque converter lock-up clutch is actuated for disengagement when a predefined limit value for the position of the lifting hydraulic mechanism of the at least one lifting device is exceeded. When the position of the lifting hydraulic mechanism falls below a predefined limit value and when the turbine rotational speed exceeds a predefined threshold value, the torque converter lock-up clutch is reengaged.

Abstract: A powertrain includes an engine, a transmission, and a torque converter located between the engine and the transmission. Subsequent to a rapid increase in engine torque commands, torque converter slip is controlled by monitoring a measured torque converter slip after the rapid increase in engine torque commands, determining a maximum measured torque converter slip value resulting from the rapid increase in engine torque commands based upon the measured torque converter slip, determining a target value to which to reduce the torque converter slip, determining a recovery profile to reduce the torque converter slip from the maximum measured torque converter slip to the target value, and utilizing the recovery profile to controllably reduce the torque controller slip. Determining the recovery profile includes commanding reducing slip through the profile at commanded torque converter slip values selected to prevent the torque converter slip from reaching zero.

Abstract: A method for controlling torque converter slip includes operating the torque converter in a controlled slip mode, monitoring slip in the torque converter, statistically analyzing the monitored slip to determine a likely condition of the torque converter, and utilizing the likely condition of the torque converter to control the torque converter slip.

Abstract: A hybrid electric vehicle has a first mode in which slippage of a clutch between an electric motor and a driving wheel is allowed and controlled by rotational speed control of the electric motor and a second mode in which the slippage of the clutch is allowed and controlled by rotational speed control of an engine. When the vehicle is stationary in the first mode, a controller reduces a control setpoint of hydraulic pressure of the clutch from an initial point. The controller identifies a reference point of the control setpoint with which actual output torque of the electric motor is substantially constant with respect to the reduction of the control setpoint. Then, the controller increases the control setpoint to a precharge point, and reduces the control setpoint to a corrected point that is lower than or substantially equal to the initial point and higher than the reference point.

Abstract: A hybrid electric vehicle has a first mode in which slippage of a clutch between an electric motor and a driving wheel is allowed and controlled by rotational speed control of the electric motor and a second mode in which the slippage of the clutch is allowed and controlled by rotational speed control of an engine. When the vehicle is stationary in the first mode, a controller reduces a control setpoint of hydraulic pressure of the clutch from an initial point. The controller identifies a reference point of the control setpoint with which actual output torque of the electric motor is substantially constant with respect to the reduction of the control setpoint. Then, the controller increases the control setpoint to a precharge point, and reduces the control setpoint to a corrected point that is lower than or substantially equal to the initial point and higher than the reference point.

Abstract: Provided is a clutch control device capable of highly precisely controlling an engaging force of a clutch even when a rotation of a motor stops or a rotation speed of the motor rapidly decreases. The clutch control device includes: a unit for determining rapid deceleration state for, based on one of the rotation speed of the motor and a rotation angle of the motor, determining a rapid deceleration state of the motor; and a motor current selection unit for, when presence of the rapid deceleration state of the motor is determined, selecting the second motor current detected in each predetermined period as a motor current used for generating the drive signal even when the rotation speed of the motor is equal to or more than the predetermined rotation speed.

Abstract: When deceleration lock-up differential pressure learning control is entered and a difference between this deceleration lock-up differential pressure instruction value and a disengagement initial pressure of lock-up smooth off control becomes smaller than prior to deceleration lock-up differential pressure learning control, the disengagement initial pressure PS of lock-up smooth off control is corrected to a low side in accordance with a difference between that deceleration lock-up differential pressure instruction value and the disengagement initial pressure. Furthermore, by changing the sweep gradient of lock-up smooth off control to a small side, and in addition, correcting the disengagement initial pressure PS of lock-up smooth off control to a low side in consideration of disengagement delay of the lock-up clutch pursuant to that sweep gradient change, the actual disengagement time during lock-up smooth off control can be matched with a target disengagement time.

Abstract: A method for controlling a torque direction transition in a dual clutch transmission includes decreasing a torque capacity of a transmission input clutch when clutch slip reaches a target slip during a power-off condition, producing a subsequent power-on condition, and increasing torque capacity of said clutch when clutch slip reaches a second target slip.

Abstract: A method for controlling an automated friction clutch arranged in a drive train between an internal combustion engine and a gearbox, including: operating the friction clutch by a clutch actuator controlled by means of a controller; transmitting actual clutch torque by means of the friction clutch; implementing actual clutch torque that can be transmitted by means of the friction clutch and that can be adapted to the transmission behavior of the friction clutch by means of a control variable of the clutch actuator associated with a target torque of the clutch torque to be transmitted; operating the friction clutch in an engaged state while the target torque is specified; and adapting the target torque depending on clutch torque estimated from the operating data of the engine. The target torque corresponds to an engine torque that is generated by the internal combustion engine and that is applied with a safety margin.

Abstract: A drive train of a motor vehicle with an internal combustion engine, a torque converter and a transmission, wherein a separation clutch is provided between the internal combustion engine and the torque converter. In order to be able to perform a creeping process at a certain creeping velocity, the separation clutch is operated slipping. This way, the gearing of the startup process can be configured long, even when using a so-called hard torque converter, without having to tolerate a creeping velocity, which is too high.

Abstract: control method of a power delivery system of a vehicle, may include determining a theoretical target slip velocity of a torque converter for slipping a damper clutch, detecting a real slip velocity of the damper clutch in a real driving condition based on the theoretical target slip velocity, expressing distributions of the real slip velocity according to an engine load ratio into a control line diagram, and controlling the real target slip velocity of the damper clutch according to the control line diagram by using the engine load ratio.

Abstract: The present invention provides a clutch torque control system of a hybrid electric vehicle, which performs an engine rotational speed control in a power generation system including an engine, a motor-generator, and a clutch for controlling connection and disconnection between the engine and the motor-generator.

Abstract: First target torque of an engine is set based on a driver's operation, a vehicle behavior, and a request for shifting gears of an automatic transmission. The engine is controlled such that the difference between the first target torque and the actual output torque of the engine is reduced. Detection torque is calculated from an operation state of the engine. In consideration of dead time in control of the engine, calculation torque is calculated from the first target torque. In addition, first lookahead torque with the dead time in the engine being removed is calculated by feedback-correcting the first target torque according to an error e between the detection torque and the calculation torque.

Abstract: A method for controlling a vehicle torque converter lockup clutch during a deceleration coasting event includes producing slip across the clutch by reducing the clutch's torque capacity, decreasing said slip by increasing said torque capacity, and maintaining slip across the clutch.

Abstract: The hydraulic control apparatus calculates a target engagement hydraulic pressure of a frictional engagement element, controls the frictional engagement element so that a revolution speed at a driving source side of the frictional engagement element is higher than a revolution speed at a driving wheel side of the frictional engagement element, outputs a command current to a solenoid valve on the basis of a map having a relationship between the target engagement hydraulic pressure and the command current, and decreases the engagement hydraulic pressure when a vehicle speed is equal to or less than a predetermined vehicle speed at which the vehicle is judged to be vehicle stop during execution of the slip control. Further, the hydraulic control apparatus corrects the map so that a variation of the command current with respect to a variation of the target engagement hydraulic pressure is small when decreasing the engagement hydraulic pressure.

Abstract: An automatic transmission has a transmission control section performing a control so that a transmission ratio defined as input rpm/output rpm of the automatic transmission becomes a target transmission ratio, a slip control section slip-controlling a frictional engagement element in the automatic transmission so that the input rpm becomes a value obtained by multiplying the output rpm by the target transmission ratio also adding a predetermined slip revolution speed; and an abnormality judgment section judging abnormality in the automatic transmission. When the slip-control is not in progress, if an actual transmission ratio is out of a predetermined range of the target transmission ratio, the abnormality judgment section judges that abnormality occurs. When the slip-control is in progress, if a value obtained by correcting the actual transmission ratio on the basis of the slip revolution speed is out of the predetermined range, the abnormality judgment section judges that abnormality occurs.

Abstract: Method for protecting a clutch of a vehicle, said vehicle being provided with an engine, drive wheels and an automated manual transmission for transmitting drive power from said engine to said drive wheels. A controller can execute the steps of: sensing a power demand from the driver which results in a clutch control where the clutch is partly engaged and clutch slip occurs, measuring travelling distance(s) of the vehicle during a predetermined first time interval, initiating a first warning measure, in order to alert the driver of excessive clutch slip, if the vehicle has traveled less than a predetermined distance during said predetermined first time interval.

Abstract: A method of managing slip in a transmission that is driven by a prime mover includes determining whether a slip condition of the transmission is present based on a slip value and reducing a torque output of the prime mover based on a torque reduction value when the slip condition is present. The method further includes storing the torque reduction value in an array if the slip condition is resolved as a result of the step of reducing and identifying a faulty component within the transmission based on the array.

Abstract: A grip force of a driving wheel is maintained by identifying an actual condition of a motorcycle and controlling a clutch in a timely manner. A clutch control system includes a clutch, an actuator unit causing the clutch to engage or disengage, a rear wheel speed sensor, a front wheel speed sensor, a clutch lever sensor and a controller controlling a control motor based on a rear wheel speed and a front wheel speed. When the rear wheel speed is lower than the front wheel speed and an absolute value of a difference between the rear wheel speed and the front wheel speed is greater than a threshold value, the control motor is driven so as to reduce a transmission force of the clutch. When an operational amount of the clutch lever is greater than a threshold value, processing to reduce the transmission force of the clutch is suspended.

Abstract: A method of operating a drive train comprising a hybrid drive with a combustion engine and an electric motor; a transmission positioned between the hybrid drive and the output; and a clutch positioned between the combustion engine and the electric motor. When the electric motor exclusively drives the vehicle, the combustion engine can be started by engaging the clutch. At the time when the electric motor permanently or without traction force interruption is coupled to the output, and the rotational speed of the electric motor is greater than the starting rotational speed of the combustion engine, and a clutch, positioned between the combustion engine and the electric motor, is engagedly and disengagedly controlled so that the clutch is brought into slippage, via partial engagement, to start the combustion engine, and thereafter the clutch is completely disengaged before reaching a synchronous rotational speed between the combustion engine and the electric motor.

Abstract: A method for controlling an automated friction clutch arranged in a drive train of a motor vehicle in the force flow between a drive engine (3) and a drive transmission (4), which is configured to close passively by spring pressure and can be disengaged and engaged by way of a pressure-medium-actuated clutch actuator (14), such that the actuation position x_K of the clutch actuator (14) or of an associated transmission element is determined and used for controlling the friction clutch (2). To improve the accuracy and reliability of the clutch actuation it is provided that in addition, an actuating pressure p_K of the clutch actuator (14) is determined and that a required change of the clutch torque M_K to a new nominal value M_K_soll takes place under pressure control, in that the actuating pressure p_K of the clutch actuator (14) is set to a nominal value p_K_soll which corresponds to the nominal value M_K_soll of the clutch torque M_K.

Abstract: The invention provides for a vehicle drive line provided with an engine (1) capable of generating an engine torque (Te), a continuously variable transmission (2), a driven wheel (5) and two friction clutches (3, 33), a first clutch (3) being positioned in the drive line between the engine (1) and the transmission (2) and a second clutch (33) being positioned between the transmission (2) and the driven wheel (5), wherein a torque (Tc-max) that is transmissible by the first clutch (3) and a torque (Tc-max) that is transmissible by the second clutch (33) are both less than a torque (Tt-max) transmissible by the transmission (2) and, at the same time, are both essentially equal to or slightly higher than the engine torque (Te).

Abstract: A vehicle driving force control device including an input shaft rotation number sensor which detects a transmission input shaft rotation number to be input from an engine to an automatic transmission, an accelerator opening sensor which detects accelerator opening, a TCU for calculating a required output of the automatic transmission based on the transmission input shaft rotation number and the accelerator opening, and an electronic control unit which controls the engine and the automatic transmission based on the required output. The TCU sets the required output to a constant value regardless of the transmission input shaft rotation number when the accelerator opening is not larger than a predetermined value, and sets to increase or decrease the required output according to increase and decrease of the transmission input shaft rotation number when the accelerator opening is larger than the predetermined value.

Abstract: An automatic shifting power transmission includes a hydrodynamic fluid drive device, a first reaction clutch disposed in series with the hydrodynamic fluid drive device, a variable capacity clutch disposed in parallel with the hydrodynamic fluid drive device, and an electric machine disposed in series with the hydrodynamic fluid drive device and the first reaction clutch. A method of controlling the automatic transmission includes slipping the first reaction clutch corresponding to a first gear engagement to affect a first gear launch maneuver when engine load is at or above a first predetermined value.

Abstract: In a hybrid vehicle provided with a power dividing mechanism comprising a clutch mechanism, an ECU performs speed-change control. In the control, the ECU performs an engage preparing process if it is necessary to engage clutch plates of the clutch mechanism with each other. In the process, the ECU switches a reference value which is referred in a feedback control for performing a rotation synchronization and a position synchronization for the clutch plates from a calculated value which is calculated from a pulse signal of first rotational sensor mounted the clutch plate to an estimated value which is estimated from a pulse signal of each of second and third rotational sensors for detecting rotational speed of each motor generators if clutch rotational speed as rotational speed corresponding to the clutch plate as an engagement element decreases to less than a criterion value.

Abstract: A method for controlling a gear shift of a dual clutch transmission having an offgoing clutch and an oncoming clutch, includes using torque transmitted by the oncoming clutch to control torque at a transmission output, using a speed of a power source to control a transfer of torque between the offgoing clutch and the oncoming clutch, and varying said torque capacity to produce a target slip across the oncoming clutch when the shift is completed.

Abstract: A method for controlling creep in a vehicle having no transmission torque converter, includes operating an input clutch of the transmission at a desired clutch torque capacity, using a feed-forward engine torque to minimize the impact on the engine speed when additional load on the engine occurs from increasing the clutch torque capacity, producing a desired clutch slip by controlling engine idle speed, and achieving a desired vehicle speed by controlling the input clutch torque capacity.

Abstract: In a method and control device for adjusting a rotational speed of a shaft of a gear change transmission of a motor vehicle, a torque required for the acceleration of the transmission and derived from a drive motor is transmitted by means of an automated clutch and using the torque the rotational speed of the shaft is precisely and rapidly adjusted to a range around a target rotational speed by defining a desired value for a position of the clutch on a rotational speed difference between a measured rotational speed of the shaft and a target rotational speed so that the gear can then rapidly be changed.

Abstract: An ECU executes a program including: a step of detecting a turbine revolution speed, a step of detecting an engine torque TE, a step of detecting a speed change ratio, a step of setting a range an enlarged slip region when a slip region enlargement condition is satisfied, and a step of enlarging the slip region toward a lock-up region side (high-load side).

Abstract: The present disclosure utilizes Non-linear Proportional and Derivative (NLPD) control on a duty cycle of an applying clutch for stationary and rolling vehicle garage shifts. The applying clutch can be engaged by as electrically activated solenoid valve, and the present disclosure utilizes NLPD control to adjust the duty cycle of the solenoid to provide a smooth vehicle garage shift engagement. The present disclosure utilizes a control algorithm based on turbine speed, turbine acceleration, and output speed. The present disclosure can utilize an existing vehicle control unit, such as an engine control unit (ECU), transmission control unit (TCU), or the like, to receive turbine speed measurements, to calculate the solenoid duty cycle using NLPD control on the turbine speed acceleration error, and to adjust the solenoid driver on the solenoid valve.

Abstract: A method for adjusting the slip of a torque converter for a plurality of selected engine speeds, transmission gears and engine torque. A sensor is used to determine vibrations transmitted through the torque converter to the driveline of the vehicle. The sensor signal is sent to a controller where it is converted to the frequency domain. If the amplitude of the frequency signal exceeds a threshold, then the algorithm increases/decreases the converter slip until the driveline vibrations equal a threshold.