An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.

Aspects of the present invention relate to a method of using a transmission with multiple clutches in order to provide improved methods of traction control on a hill ascent. Embodiments provide for the use of power-shift, automatic or dual clutch gearboxes.

An automatic transmission control device implements a downshift by disengagement of a clutch that is engaged in a gear position before the downshift. It is determined whether an engine state is in a predetermined region in which a change of an engine torque per a change of an accelerator pedal opening is smaller than that in another region, and the engine torque is within a predetermined range, and an engine rotational speed is within a predetermined range. It is determined whether an operating state is in a predetermined state of accelerator operation in which the accelerator pedal opening is larger than a predetermined value, and an accelerator pedal opening change rate has an absolute value smaller than a predetermined value. The downshift is inhibited in response to determination that the engine state is in the predetermined region and the operating state is in the predetermined state of accelerator operation.

A method of transitioning between two intake valve lift states while providing constant engine torque output comprehends the steps of receiving a lift change request from an engine control device, determining the current phase angles of the camshafts, and determining whether the intake and exhaust camshafts are at transition positions. The transition positions are experimentally or empirically determined combinations of operating conditions that result in constant engine torque output before and after the intake valve lift transition. If they are, an appropriate, i.e., low to high or high to low cam lift state transition of the intake valves occurs. If they are not, the cam phasers move the intake and exhaust camshafts to transition positions. When the cam phasers have moved the intake and exhaust camshafts to the transition positions, i.e., positions of constant engine torque output, the intake valve lift transitions from high to low or low to high.

A control apparatus for a vehicle provided with a step-variable transmission which is disposed between drive wheels and a drive power source including at least an engine, and which is shifted by changing operating states of coupling devices, the control apparatus including an engine stability time estimating portion configured to estimate a length of stability time required for stabilization of an output state of the engine, when a determination to implement a power-on shift-down action of the step-variable transmission is made, and a control portion configured to delay a moment of generation of a shift-down command to implement the power-on shift-down action of the step-variable transmission, with respect to a moment of the determination to implement the power-on shift-down action, where the estimated length of stability time is longer than a predetermined value.

This invention pertains to the field of power transmission. Machines using a power transmission mechanism for transmission of the mechanical power produced by a source (engine (2), electric motor, pneumatic and hydraulic pump) to another component of the machine (wheel (21), electric motor, electric generator, pneumatic and hydraulic pump) through multiple transmission paths (different gear ratios (14), (15)) are subjects of this invention. It is disclosed that control of a switching from one power transmission path to another is done in a manner involving simultaneous load transfer and speed synchronization rather than sequential performance of these two functions, and the resulting method developed in the invention leads to switching operations that produce less disturbance at the input of the said component. The said method is applied to the problem of controlling gearshifts in automatic transmissions of ground vehicles.

A method of determining torsional deformation in a drivetrain e.g. of a wind turbine. To provide a reliable and simple deformation assessment, the method comprises the step of generating a first signal representing first rotational speed of a low speed shaft, generating a second signal representing the second rotational speed of a high speed shaft, and determining torsional deformation based on changes in the ratio between the first and second signals.

Aspects of the present invention relate to a method of using a transmission with multiple clutches in order to provide improved methods of traction control on a hill ascent. Embodiments provide for the use of power-shift, automatic or dual clutch gearboxes.

An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.

An automatic transmission control device implements a downshift by disengagement of a clutch that is engaged in a gear position before the downshift. It is determined whether an engine state is in a predetermined region in which a change of an engine torque per a change of an accelerator pedal opening is smaller than that in another region, and the engine torque is within a predetermined range, and an engine rotational speed is within a predetermined range. It is determined whether an operating state is in a predetermined state of accelerator operation in which the accelerator pedal opening is larger than a predetermined value, and an accelerator pedal opening change rate has an absolute value smaller than a predetermined value. The downshift is inhibited in response to determination that the engine state is in the predetermined region and the operating state is in the predetermined state of accelerator operation.