A method is provided for controlling a gear change in the case of a non-synchronized dog-shift transmission having at least one shift fork controllable by way of a selector drum, wherein, by way of a position sensor on the selector drum, the rotational position of the selector drum is sensed and is transmitted to an electronic control unit for controlling a drive motor. By use of the sensed rotational position, the control unit detects whether the/a shift fork is in an intermediate position, in which none of the two possible gears associated with the shift fork is engaged. If the shift fork is in the intermediate position, the rotational speed of the drive motor is controlled to a middle value between the target rotational speeds of the two possible gears if in addition the clutch between the drive motor and the dog-shift transmission is open.

An engine output control device controls engine output at a time of a downshift speed change of a transmission. The engine output control device includes: engine speed detecting means for detecting an actual engine speed NeJ of a crankshaft; and engine output adjusting means capable of adjusting the engine output according to an operation of a rider. The smaller of a requested engine output PA calculated on a basis of the actual engine speed NeJ and a rider requested engine output PB adjusted by the engine output adjusting means is output as the engine output.

Methods and systems for a clutch assembly in an electric drive axle of a vehicle are provided. In one example, a clutch assembly in a gear train is provided that includes a locking clutch. The locking clutch includes a gear including a plurality of teeth having at least one tooth with a tapered end, an indexing shaft rotationally connected to an output shaft, a shift collar mounted on the indexing shaft, configured to translate on the indexing shaft into an engaged and disengaged configuration, and including a plurality of teeth on a face, where at least one tooth in the plurality of teeth in the shift collar includes a tapered end, and an indexing mechanism coupled to the shift collar and the indexing shaft and configured to accommodate for indexing between the indexing shaft and the shift collar during shift collar engagement.

Methods and systems are provided for controlling engine operation in response to a request to shift a transmission gear. In one example, a method may include maintaining operating conditions of an engine and redirecting electric power generated via the engine from a traction motor to a battery in response to a request to shift a transmission while the driveline is operating in a series mode. In this way engine efficiency may be improved and a time frame for shifting a transmission gear may be reduced responsive to a gear shift request while the powertrain is operating in series mode.

A transmission comprises a moving mechanism to generate axial force to move the one rotary member and releases the axial force according to generation of coasting torque, an urging mechanism to urge the one rotary member with force being poorer than the axial force being generated by the moving mechanism so that the meshing teeth mesh, the contact body of the urging mechanism arranged in a supporting hole formed on the torque transmission member in a radial direction, and an urging and converting part provided to receive the contact body being urged in the radial direction by the urging functional part and convert a direction of the urging to the axial direction to urge the axial movement of the one rotary member.

Methods and systems for a clutch assembly in an electric drive axle of a vehicle are provided. In one example, a clutch assembly in a gear train is provided that includes a locking clutch. The locking clutch includes a gear including a plurality of teeth having at least one tooth with a tapered end, an indexing shaft rotationally connected to an output shaft, a shift collar mounted on the indexing shaft, configured to translate on the indexing shaft into an engaged and disengaged configuration, and including a plurality of teeth on a face, where at least one tooth in the plurality of teeth in the shift collar includes a tapered end, and an indexing mechanism coupled to the shift collar and the indexing shaft and configured to accommodate for indexing between the indexing shaft and the shift collar during shift collar engagement.

A method of controlling a vehicle drivetrain by an electric motor, in order to synchronize the speed of an internal combustion engine and the speed of gears in the drivetrain, wherein if a speed synchronization error e.sub.sync(t) is controlled to remain within a prespecified region for a specific period of time, the synchronization is finished, and a gear may be engaged.

There are provided a transmission control device and a transmission control method that controls a prime mover in a system including the prime mover and a gear transmission. A processing circuitry of the transmission control device executes a process including: determining whether to fall into a predetermined situation at a time of acquiring a shift command; when it is determined as being the predetermined situation, starting a separation control that adjusts an output of the prime mover such that a dog is separated from an abutment surface against which the dog abuts at the time of acquiring the shift command; and after the separation control is completed and before the dog at the first transmission gear position moves out of an accommodation space at the first transmission gear position, starting a synchronous control relating to the dog and transmission gears.

Described herein are systems and techniques for utilizing a powered axle that includes a plurality of transmissions. The powered axle may include separate transmissions to power wheels on opposite ends of the powered axle. Each transmission of the powered axle may be operated independently of the other transmission. As such, the plurality of transmissions of the powered axle may be shifted independently of each other. Various control schemes may be provided for operation of such transmissions.

A method of operating a transmission which is shifted to various operating conditions by engaging shifting elements. At least one of the shifting elements is an interlocking shifting element which has to be engaged to obtain at least one defined operating condition of the transmission during which force flows between an input and an output shaft. When a command is received to engage the interlocking shifting element, a rotational speed of the transmission input shaft is displaced in the direction toward a synchronous rotational speed produced in the engaged operating condition of the interlocking shifting element at least as a function of the rotational speed of the transmission output shaft. When the variation of the rotational speed of the transmission input shaft crosses a predefined rotational speed threshold, the interlocking shifting element is actuated in its engaging direction.