The disclosure is concerned with control system and control method, for a vehicle including a driving power source, drive wheels, a first clutch, and a second clutch. An electronic control unit, which is included in the control system, places the first clutch in a half-engaged state with a predetermined clutch torque capacity, when the vehicle is started, performs start control in a first mode using the second clutch, by gradually increasing a clutch torque capacity of the second clutch from a released state, and switches the start control from the first mode using the second clutch to a second mode using the first clutch, when the increased clutch torque capacity of the second clutch reaches the clutch torque capacity of the first clutch.

A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method includes adjusting a pressure of the driveline disconnect clutch as a function of an engine pull-up torque minus a driver demand torque when the pressure of the driveline disconnect clutch is between a torque stroke pressure and a hydraulic stroke pressure.

A gear-position learning device for an automatic clutch transmission includes a transmission configured to be shifted by an operation of a driver of a vehicle, a clutch device disposed in a transmission path between the transmission and an engine and configured to be connected and disconnected by actuation of a clutch actuator, a controller configured to control connection and disconnection of the clutch device performed by the clutch actuator, a shift drum configured to rotate according to a shift operation that the driver performs on a shift operator and switch the shift stage of the transmission, and a rotational position defining mechanism configured to define a rotational position of the shift drum, wherein the controller has a learning mode for learning a rotation angle of the shift drum and is configured to control connection and disconnection of the clutch device during the learning mode such that the shift drum is at a rotational position determined by the rotational position defining mechanism.

A power transmission device for a vehicle includes a control unit adapted to automatically control engagement or disengagement of a clutch, and is further equipped with a clutch lever for manually engaging or disengaging the clutch. The power transmission device includes a manual mode in which the clutch is engaged or disengaged by a driver performing an engagement or disengagement operation with the clutch engagement/disengagement operating element and an automatic mode in which the clutch is engaged or disengaged under the control of the control unit without the driver performing the engagement or disengagement operation. The manual mode or the automatic mode is selectable by the driver. In the manual mode, it is further possible to select a plurality of control modes with differing levels of intervention of the automatic control.

The present disclosure relates to a technique for improving durability of a clutch and shifting stability. The present disclosure provides a method of controlling a clutch of an automated manual transmission (AMT) vehicle, which reduces a micro-slip control time in order to improve durability of the clutch by performing a full-lock control of the clutch after slip control for learning a clutch characteristic curve. Additionally, the method shortens time to open the clutch for a subsequent shifting by predicting the time when a shift restarts after the full-lock control and by resuming the micro-slip control.

A method and a system for controlling a backlash of a powertrain included in a vehicle in connection with a gear shifting operation is presented. The method comprises: controlling, in connection with a first gear shifting operation, a clutch included in the powertrain to a slipping position, in which slipping position the clutch transfers a slipping torque that is less than a torque being transferred in a closed position for the clutch; analyzing a change of a rotational speed for an input shaft of a gearbox included in the powertrain; determining a position for the clutch, for which position the change of the rotational speed has a value corresponding to a backlash torque, the backlash torque having a predetermined value for eliminating the backlash; and utilizing the determined clutch position for controlling the clutch in connection with a second subsequent gear shifting operation.

Methods and systems are provided for operating a vehicle that may be propelled via a primary axle and a secondary axle. In one example, a propulsion source of a secondary axle may be decoupled from at least one wheel via a dog clutch that includes teeth. The dog clutch may be disengaged in a way that reduces driveline noise and may reduce a possibility of driveline degradation.

A start control device is a start control device that controls start of a vehicle including a clutch that is engaged by the hydraulic pressure supplied from a hydraulic pressure supply source and a start device that starts a vehicle driving source, and includes: a hydraulic pressure control unit that controls so that the hydraulic pressure supply source supplies the hydraulic pressure to the clutch if a start condition for the vehicle is satisfied; and a start device control unit that controls the start device so that the rotation speed of the vehicle driving source reaches the predetermined rotation speed after the clutch is engaged.

The present invention relates to a saddle-ride type vehicle comprising a clutch assembly (4), interposed between an engine (2) and a gearbox (3), which includes a clutch device (11) in turn comprising two clutch elements (one integral with the shaft of the engine and the other with the input shaft of the gearbox) and return means (12) that keep these elements (11A, 11B) in contact in a closure condition of the clutch. According to the invention, the clutch assembly (4) further comprises an operating device (21) of the clutch device that causes detachment of the elements (11A, 11B) of the clutch device up to an opening condition of the clutch assembly. This latter further comprises a control device (6) to limit the torque peaks during gear change. This device comprises an actuation means (5) that, during gear change, exerts a predetermined force (S) in contrast to the force exerted by said return means (12) of the clutch assembly, wherein said predetermined force (S) is less than the force (F) generated by the return means (12) so as to cause a mutual slip of the elements (11A, 11B) of the clutch device (11) without said opening condition being reached. The operating device (21) is of hydraulic type and comprises a primary pump (22) operated by means of a control lever (23), wherein this primary pump (22) is hydraulically connected, through a primary hydraulic circuit (16), to a primary piston (24) acting on at least one of the elements (11A, 11B) of the clutch device (11) in opposition to the return means (12) so that, following an action on the control lever (23), the primary piston (24) exerts an action the elements (11A, 11B) determining the opening condition. According to the invention, the control device (6) comprises a secondary piston (25) connected to the primary piston (24), wherein the actuation means (5) exerts, directly or indirectly, the predetermined force (S) on the secondary piston (25), said predetermined force (S) being transferred to the primary piston (24) in opposition to the force (F) of the return means (12).

A method for adjusting and adapting an operating point of a hydraulic actuator arrangement, in which a volume flow source is connected to a hydraulic cylinder via a pressure line that is filled with a hydraulic fluid. The method includes regulating a volume of the hydraulic fluid by the volume flow source, wherein an operating point of a position of the actuator arrangement corresponds, with respect to a predefined parameter, to a device which is to be actuated by the actuator arrangement. A modified volume of the hydraulic fluid which is necessary to adjust the operating point is derived from a rotational position of a volume flow source motor and/or of the volume flow source.