Methods and systems are provided for controlling and diagnosing one or more clutches in a transmission. In one example, a method for operation of a vehicle system is provided that includes at a diagnostic controller or processing unit independent from a driveline controller or processing unit, respectively, determining an engagement state of a clutch in a transmission of the vehicle system, wherein the engagement state is selected from a group of three or more clutch engagement states. The method further includes identifying an unauthorized clutch state based on the engagement state of the clutch and a speed of the vehicle and responsive to the identification of the unauthorized clutch state, operating the vehicle system in a fault state.

A drive switching mechanism of a utility vehicle includes: a two-wheel drive and four-wheel drive switching device that switches between two-wheel drive and four-wheel drive of the utility vehicle; and a control unit that controls the drive switching mechanism. The two-wheel drive and four-wheel drive switching device switches between two-wheel drive and four-wheel drive by using a first clutch. The control unit permits the two-wheel drive and four-wheel drive switching device to switch from two-wheel drive to four-wheel drive when a rotation difference of the first clutch becomes equal to or smaller than a predetermined value.

Disclosed is a method for controlling engagement of an engine clutch in a hybrid electric vehicle in which an engagement control method of the engine clutch is accurately determined so as to minimize a determination error and a sense of discontinuity caused by conversion of the engagement control method resulting therefrom.

A method for determining the engaged gear in a manual gearbox of a vehicle comprising a number of gears is described, wherein the vehicle comprises an engine, the manual gearbox, and at least one clutch. The method comprises the following steps: determination of the revolution rate of the engine as a function of time; differentiating the determined revolution rate of the engine against time; determination of the speed of the vehicle; and determination of the engaged gear based on characteristic curves of the revolution rate of the engine as a function of time for a number of the gears in the case of a fixed rate of engagement of the clutch, the revolution rate of the engine, the differential of the revolution rate of the engine against time and the speed of the vehicle.

A vehicle includes a transmission, an engine, a disconnect clutch, an inertial measurement unit, and a controller. The transmission has an input shaft and an output shaft. The engine is configured to generate and deliver torque to the input shaft. The disconnect clutch is configured to connect and disconnect the engine from the input shaft. The disconnect clutch is also configured to crank the engine during an engine start. The inertial measurement unit is configured to measure inertial forces exerted onto the vehicle. The controller is programmed to, in response to a command to adjust a torque of the disconnect clutch to a desired value that is derived from the inertial forces and a vehicle velocity, drive the clutch actuator pressure to a value that corresponds to the desired value.

This vehicle transmission system includes a transmission (21) in which a gear is shifted by an operation of a driver of a vehicle (1), a clutch device (26) that is disposed in a motion transfer path between the transmission (21) and an engine (13) of the vehicle (1), and is disconnected and connected by an action of a clutch actuator (50), and a clutch control unit (61) that is configured to control disconnection and connection of the clutch device (26) by the clutch actuator (50). In a case where the vehicle (1) is started with a gear position of the transmission (21) located at or above a gear that is set in advance, and a vehicle speed (V) is less than or no higher than a set value (v2) that is set in advance, the clutch control unit (61) transitions to clutch capacity-limiting control in which a clutch capacity is reduced below that during normal clutch control.

A driving assistance system for a work vehicle may comprise a service brake configured to decelerate the work vehicle upon actuation of the service brake, a parking brake and a transmission including a clutch. A controller may be configured to disengage the clutch when the work vehicle speed is less than a speed threshold and when the service brake is actuated, whereby the work vehicle is brought to a stop.

A method for controlling a clutch unit for a drive train of a motor vehicle, wherein the clutch unit comprises a wet-running friction clutch for controllably transmitting torque from an input element to an output element of the clutch unit, wherein the clutch unit comprises oil for cooling the friction clutch, wherein heat inputs which contribute to heating the oil of the clutch unit are calculated, heat outflows which contribute to cooling the oil of the clutch unit are calculated and, as a function of the heat inputs and heat outflows, a maximum admissible clutch torque is calculated, and wherein the current clutch torque of the friction clutch is limited to the maximum admissible clutch torque.

Embodiments of the present invention provide an electric machine control system for a vehicle, the electric machine control system comprising one or more controllers, wherein the vehicle comprises an electric machine arranged to be selectively coupleable to provide torque to at least one wheel of an axle of the vehicle, the control system comprising input means arranged to receive a speed signal (410) indicative of a speed of the vehicle and a status signal (470) indicative of a status of a coupling of the electric machine to the at least one wheel of an axle of the vehicle, output means (340) arranged to output a coupling signal to control coupling of the electric machine to the at least one wheel of the axle, and processing means arranged to determine (1210) a coupling state of the electric machine to the at least one wheel of the axle and to control the output means to output (1220) a coupling signal indicative of the determined coupling state, wherein the processing means is arranged, in dependence on the status signal being indicative of a failure (1230) to change the coupling state of the electric machine to the at least one wheel of the axle in dependence on a change in the determined coupling state, to control the output means to output the coupling signal (345) indicative of a retry (1250) of the change in the coupling state in dependence on the speed signal.

A control method of an electromagnetic clutch in a hybrid power system and a hybrid power system are disclosed. Besides the electromagnetic clutch, the hybrid power system further comprises an engine or motor, a motor, an electromagnetic clutch controller and a power supply system. The power supply system comprises: a low-voltage battery, a standby power supply system and a switching circuit. The electromagnetic clutch is used to control connection of the motor. The control method comprises: monitoring whether a voltage of the low-voltage battery is lower than a target value, and judging whether the low-voltage battery fails; using the switching circuit to switch to the standby power supply system to supply power to the electromagnetic clutch and the electromagnetic clutch controller; using the electromagnetic clutch controller to judge an engaged or disengaged state of the electromagnetic clutch; and further controlling the electromagnetic clutch according to the engaged or disengaged state. When the low-voltage battery power supply fails, the switching circuit switches to the standby power supply system to supply power, thereby ensuring that the electromagnetic clutch is in a reasonable state and make the hybrid power system more safe and reliable.