A method for preventing an incorrect learning of a clutch torque of a transmission of a vehicle may include a controller estimating an engine-based clutch torque estimated based on an engine torque; the controller estimating a wheel-based clutch torque estimated based on a driveshaft torsional torque; the controller determining a torque error, which is a difference between the engine-based clutch torque and the wheel-based clutch torque: the controller allowing a learning of the clutch torque when the torque error is equal to or less than a predetermined reference torque; and the controller prohibiting the learning of the clutch torque when the torque error is greater than the predetermined reference torque.

A shift control method for a vehicle with a double clutch transmission (DCT) is configured such that when a power-on upshift is initiated, during a target time for a controller to perform a torque phase, a release-side clutch is gradually released, an engine torque is gradually increased to a basic engine torque or more, and an engagement-side clutch torque is increased according to an increase in the engine torque and a vehicle speed; and when the release-side clutch is completely released, the controller reduces the engine torque while gradually reducing the engagement-side clutch torque to be equal to the basic engine torque, to perform an inertia phase such that an engine speed is synchronized with an engagement-side clutch speed.

A drive system is provided with a first motor generator as a power source, and a multistage gear transmission for changing the speed of output from the first motor generator and transmitting the output to drive wheels. The multistage gear transmission has a plurality of engagement clutches as shifting elements that are meshingly engaged upon movement from a disengaged position. This hybrid vehicle is provided with a start control device where, when a start clutch has been engaged while the vehicle is stopped, the start control device maintains the engagement of the start clutch for a duration that includes when the vehicle is stopped and until the next vehicle start.

A transmission for an electric vehicle, may include a concentric deceleration device for receiving power from a motor shaft and for decelerating; an output shaft disposed in parallel with the input shaft; a hollow shaft rotatably provided on the input shaft; a clutch device provided to switch the transmission state of power from the input shaft to the hollow shaft; a first synchronizer having a hub fixed to the input shaft; a second synchronizer having a hub fixed to the hollow shaft; a plurality of driving gears having different sizes and provided on the input shaft and the hollow shaft to be engaged with at least one of the first synchronizer and the second synchronizer; and a plurality of driven gears provided on the output shaft to be engaged with the plurality of driving gears to form different shift ratios, respectively.

A control apparatus of a power transmission system for a vehicle includes an electronic control unit. When an input rotational speed of an input-side rotary member is lower than an output rotational speed of an output-side rotary member in a two-way clutch, and a shift request to form a shift stage in which the two-way clutch is switched to a lock mode is generated, the electronic control unit switches the two-way clutch to the lock mode, after the input rotational speed of the input-side rotary member is made substantially equal to the output rotational speed of the output-side rotary member.

A mechanical transmission and a method for controlling the mechanical transmission. The mechanical transmission includes an input shaft, a first engagement sleeve, a second engagement sleeve, a clutch, an odd gear output shaft and an even gear output shaft. A power transmission route is formed, then by sequentially controlling the coupling and disengaging of the clutch, and the combining and quitting of the first engagement sleeve and the second engagement sleeve, the power of the input shaft is alternatively conveyed to the odd gear output shaft or the even gear output shaft, thus up-shift and down-shift operations are completed. In this way, the number of the clutch is reduced, which decreasing the volume of the transmission accordingly, and meanwhile reducing the dragging resistance produced by the clutches and the cost of the transmission, also improving the transmission efficiency.

An acceleration control method for a dual clutch transmission (DCT) vehicle, may include determining whether an engine speed is lower than a desired shift stage input shaft speed by a controller when a driver's demand for acceleration is verified, determining whether an engine speed increased by the demand for acceleration is equal to or greater than the desired shift stage input shaft speed by the controller, feedback-controlling an engagement-side clutch to reduce a slip caused by a difference between the engine speed and the desired shift stage input shaft speed while maintaining an engine torque by the controller when the engine speed is verified to be equal to or greater than the desired shift stage input shaft speed, and completing control by verifying whether synchronization of the engine speed with the desired shift stage input shaft speed is stabilized.

An engagement operation of a dog clutch is carried out while an engagement operation of a second clutch is being carried out, that is, during a situation that an uplock is hard to occur because of a phase shift generated between meshing counterpart members of the dog clutch. Thus, the dog clutch is easily engaged, and it is possible to facilitate preparation for transmission of power through a first power transmission path. If the dog clutch is not engaged, the second clutch is engaged and a second power transmission path is established, so it is possible to start moving a vehicle by transmitting power through the second power transmission path. Thus, when the dog clutch is in a non-engaged state at the time of an N-to-D shift during a stop of the vehicle, it is possible to ensure the startability of the vehicle.

A method for operating a transmission for a motor vehicle having an input shaft, a first shaft connectable to the input shaft via a first input clutch and a second shaft connectable to the input shaft via a second input clutch, a plurality of separating clutches, and an output shaft. Different gear ratios between the input and output shafts are implementable by selective engagement of the plurality of clutches. A first torque transmission path between the first and second shafts is engageable with a first friction-locking clutch and a second torque transmission path between the first and second shafts is engageable with a second friction-locking clutch. The method includes actuating, at least intermittently during a synchronization phase in an upshift process of the transmission, the first friction-locking clutch to transmit a first torque and the second friction-locking clutch to transmit a second torque.

Disclosed is a gear shift control method of a Dual Clutch Transmission (DCT) vehicle. The gear shift control method includes a gear shift start determination step of determining whether a kick down shift, a biaxial shift determination step of determining, when the kick down shift is started, whether the gear shift is a biaxial shift; a clutch torque control step of uniformly decreasing torque of a release-side clutch and uniformly increasing torque of a connection-side clutch to synchronize revolutions per minute of a target gear input shaft with increasing revolutions per minute of an engine, a clutch synchronization determination step of determining whether the revolutions per minute of the target gear input shaft is synchronized with the revolutions per minute of the engine by the clutch torque control, and a gear shift performing step of performing gear shift control for engaging the target gear.