To allow a rider to sense torque in a low-speed traveling mode, a control device has a forward-and-reverse clutch oil pressure controller. In a low-speed traveling mode, the forward-and-reverse clutch oil pressure controller performs hunting control on driving torque, which is transmitted to a rear wheel from a crankshaft of an engine through a clutch device, a transmission, and a drive shaft, if vehicle speed stays within a second vehicle speed range for a predetermined time.

A vehicle travel control method and a vehicle travel control device carries out a downshift control of an automatic transmission when a vehicle speed increases from a set vehicle speed during a constant speed travel control by at least a first prescribed value. Subsequent downshift control of the automatic transmission is prohibited upon determining the vehicle speed has increased from the set vehicle speed by at least the first prescribed value due to an operation of an operating element by the driver during constant speed travel control. Downshift control of the automatic transmission is executed upon determining insufficient deceleration of the vehicle exists where the driver is not operating the accelerator pedal during prohibition of the downshift control.

A CPU sets a gear ratio, which is an action, on the basis of an accelerator operation amount, a vehicle speed, a gradient, a curvature, and a current gear ratio, until a predetermined amount of time elapses. The CPU operates a transmission in accordance with the set gear ratio and obtains a rotation speed NE of a crankshaft at that time. When the predetermined amount of time has elapsed, the CPU updates an action value function by providing a reward in accordance with whether the number of times of switching the rotation speed NE or the gear ratio meets a standard.

An object is to reduce a delay in response. An automatic gear changing control device includes a sleeve which is moved by an actuator to perform an engagement operation, an engine which is connected to an input shaft, and a control unit which controls the movement of the sleeve by the actuator and controls the rotation of the input shaft by the engine or a motor generator. The control unit performs synchronization control of controlling the rotation of the input shaft for the engagement operation at a different gear stage after the engagement is released and starts shift control of moving the sleeve to an engagement completion position by the actuator before at least the synchronization is completed.

A vehicle travel control method and a vehicle travel control device carries out a downshift control of an automatic transmission when a vehicle speed increases from a set vehicle speed during a constant speed travel control by at least a first prescribed value. Subsequent downshift control of the automatic transmission is prohibited upon determining the vehicle speed has increased from the set vehicle speed by at least the first prescribed value due to an operation of an operating element by the driver during constant speed travel control. Downshift control of the automatic transmission is executed upon determining insufficient deceleration of the vehicle exists where the driver is not operating the accelerator pedal during prohibition of the downshift control.

An ECU determines whether or not a road surface changes from a low μ road surface to a high μ road surface based on image data obtained by a camera sense. When the ECU determines that the accelerator pedal operation amount deceases greatly in a predetermined determination period from a time point at which a drive wheel slip state occurs in a case where the ECU determines that the road surface changes from the low μ road surface to the high μ road surface, it prohibits upshift operation of an automatic transmission over a predetermined period from that time point.

A CPU sets a gear ratio, which is an action, on the basis of an accelerator operation amount, a vehicle speed, a gradient, a curvature, and a current gear ratio, until a predetermined amount of time elapses. The CPU operates a transmission in accordance with the set gear ratio and obtains a rotation speed NE of a crankshaft at that time. When the predetermined amount of time has elapsed, the CPU updates an action value function by providing a reward in accordance with whether the number of times of switching the rotation speed NE or the gear ratio meets a standard.

A method for monitoring a signal of a sensor is provided. With the aid of the sensor, a current actuating-travel position of at least one movable shift-element half of a form-locking shift element (A, F) of a transmission (3) is detected during a disengagement or an engagement of the shift element (A, F). A malfunction of the sensor is detected when the current actuating-travel position of the movable shift-element half is located outside the actuating-travel range defined by the end positions and is spaced apart from the first end position or from the second end position by an extent greater than a threshold value. Additionally, it is determined, during a subsequent actuation of the shift element (A, F), depending on rotational speeds of components of the transmission (3), whether the movable shift-element half is located in a demanded end position.

A method for operating a vehicle drive train (1) comprising a prime mover (2), transmission (3), and comprising a driven end (4) may include limiting, during a demand for engaging a form-locking shift element (A, F) of the transmission (3) when a rotational speed of the driven end (4) is close to zero, a rate of change of a transmission input torque present at the form-locking shift element (A, F) to a value. Below the value, forces present at the form-locking shift element (A, F) during an engagement process are less than a load limit. Above the value, irreversible damage to the form-locking shift element (A, F) occurs.

A method for operating a transmission (3) is provided, which includes a hydraulic pump drivable on a transmission-input end and at least one form-locking shift element (A, F). One of the shift-element halves is displaceable between a first end position and a second end position with a hydraulic pressure of the hydraulic pump. The current position of the shift-element half is detected with a sensor and is stored as a specified end-position value if the shift-element half is located in one of the end positions, the hydraulic pump is driven, and the shift-element half is actuated, with the hydraulic pressure, towards the current end position. When the hydraulic pressure is less than a threshold value, a deviation is determined between the current position of the shift-element half and the specified end-position value. The hydraulic pressure is increased when the deviation is greater than a threshold value.