A method is provided for estimating input torque and output torque in a continuously variable transmission having a variator. The method comprising the steps of determining (202) a transmission Input and/or output speed, calculating (204) the speed of each of a plurality of transmission components by reflecting the transmission input and/or output speed through the transmission to each of the plurality of transmission components, and calculating (208) the speed rate of change of each of the plurality of transmission components. The inertia torque of each of the plurality of transmission components is calculated (210) based upon its respective speed rate of change and a predetermined component inertia value (209). The method further comprises the steps of determining (211) a motor torque of the variator, and calculating (212) a transmission input torque and transmission output torque by reflecting the motor torque of the variator through the transmission to the transmission input and output. The calculated transmission Input and output torque values are adjusted (214) to account for the calculated inertia torque values of those of the plurality of transmission components which lie between the variator and the transmission input, and the variator and the transmission output, respectively.

A method is provided for estimating input torque and output torque in a continuously variable transmission having a variator. The method comprising the steps of determining (202) a transmission input and/or output speed, calculating (204) the speed of each of a plurality of transmission components by reflecting the transmission input and/or output speed through the transmission to each of the plurality of transmission components, and calculating (208) the speed rate of change of each of the plurality of transmission components. The inertia torque of each of the plurality of transmission components is calculated (210) based upon its respective speed rate of change and a predetermined component inertia value (209). The method further comprises the steps of determining (211) a motor torque of the variator, and calculating (212) a transmission input torque and transmission output torque by reflecting the motor torque of the variator through the transmission to the transmission input and output. The calculated transmission input and output torque values are adjusted (214) to account for the calculated inertia torque values of those of the plurality of transmission components which lie between the variator and the transmission input, and the variator and the transmission output, respectively.

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.

Disclosed is a method of controlling a shifting time and a transmission controlled by the method. A method of controlling a shifting time of an automatic transmission mounted on a vehicle to control the driving of the transmission by incorporating the state of an engine includes an entry condition determination step of determining whether the engine of the vehicle being driven is a full throttle driving state and a shifting point correction logic entry condition is satisfied, an engine speed calculation step of calculating an expected maximum engine speed during gear shifting, and a shifting time delay step of delaying a shifting time during a specific time if an expected maximum engine speed value calculated in the engine speed calculation step is less than a preset value. Accordingly, a shifting pattern into which maximum acceleration performance set through maximum performance of an engine has been incorporated can be implemented.

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.

In gear-shift control apparatus and method for a vehicular transmission, a variator which is interposed between an engine and driving wheels and which is capable of modifying a gear (speed) ratio continuously; a sub transmission which is installed in series with the variator and which is capable of switching a plurality of gear-shift stages through a replacement of engagement elements; and a transmission controller which performs a gear ratio control for the variator and a gear-shift stage control for the sub transmission are installed. During a deceleration through a second speed stage of the sub transmission, when the variator is a state in which the variator is at a lowest gear (speed) ratio, a down-shift in which the sub transmission is forced to perform the gear-shift from a second speed stage to a first speed stage, with the variator maintained at the lowest gear (speed) ratio.

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 control system controls a power transmission system located between a motive power source and drive wheels. The power transmission system includes a fluid coupling and an engagement device. The control system includes an electronic control unit configured to: obtain information concerning vibration of the power transmission system; determine whether the vibration of the power transmission system is in a resonance region of the power transmission system; control the engagement device so that the engagement device slips, when the electronic control unit determines that the power transmission system is in the resonance region; and control the motive power source when the electronic control unit determines that the power transmission system is in the resonance region, so that a rotational speed of the motive power source increases as compared with a case where the power transmission system is not in the resonance region.

According to the present invention, there is provided a method of reducing output torque deficits during the launch of a vehicle having a continuously variable transmission, wherein the variator has an input connected to a prime mover and an output. The method comprises the steps of determining a rate of change of ratio in the transmission, and predicting a required motor speed ratio rate of change value of the variator on the basis of: (i) the determined rate of change of ratio in the transmission, and (ii) the configuration of the transmission. The speed of the variator output is adjusted so as to achieve the required motor speed ratio rate of change value.

A method for a more efficient use of a vehicle combustion engine during driving, the vehicle including an automatic step geared transmission. The method includes the steps of sensing current engine rotational speed and engine rotational speed increase, estimating necessary minimum upshift engine rotational speed for a coming gear upshift, registering that the engine rotational speed stops increasing without reaching the minimum upshift engine rotational speed, and where the engine rotational speed stops increasing relatively close to a maximum engine rotational speed where engine efficiency is relatively low and, automatically controlling engine output torque in order to limit the engine rotational speed to a first predetermined engine speed where engine efficiency is relatively high.