A control device for an automatic transmission includes a continuously variable transmission mechanism, a torque converter, a target transmission ratio calculation unit, a feedback control unit, and a phase compensation unit. The torque converter has a lock-up clutch. The target transmission ratio calculation unit is configured to calculate a target transmission ratio based on a travelling state. The feedback control unit is configured to perform feedback control based on an actual value indicative of a state of the continuously variable transmission mechanism. The phase compensation unit is configured to perform phase lead compensation of the feedback control based on the travelling state. The phase compensation control unit is configured to halt the phase lead compensation when an unstable travelling state of a vehicle is detected. The phase compensation control unit is further configured to release the lock-up clutch when the phase lead compensation is halted.

A method to control a road vehicle provided with a servo-assisted transmission during a slowing down phase; the control method generally includes, when the servo-assisted transmission is in an automatic operating mode, the steps of: calculating, assuming that a pressing of the brake pedal remains constant, an opening time interval needed to allow the road vehicle to reach an opening speed at which a clutch of the servo-assisted transmission is definitively opened; calculating a number of downshifts that can be carried out in the opening time interval based on a time needed to carry out a downshift; scheduling the downshifts to be carried out in order to get from the current gear engaged in the servo-assisted transmission to an opening gear with which the clutch of the servo-assisted transmission is definitively opened, so as to carry out no more than the number of downshifts that can be carried out in the opening time interval; and carrying out the scheduled downshifts.

A method to control a road vehicle for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission; the control method comprises the steps of: detecting a condition of slowing down of the road vehicle and, simultaneously, detecting a driver's request for a multiple downshift; carrying out, in succession, a plurality of downshifts while the road vehicle is slowing down and in an autonomous manner regardless of further interventions of the driver; determining a duration of a shift time interval; and carrying out each downshift following a first downshift when said shift time interval has exactly elapsed since the previous downshift.

A manual shift lever system may be provided that includes: a shift lever which includes a rod and a stopper formed on the rod; a shift lock unit which limits a movement of the rod; and a control unit which, when a speed of a vehicle is greater than a critical speed of a predetermined gear limits the movement of the rod in a shift direction of the predetermined gear. The shift lock unit includes: at least one shift lock cam part including a main cam, a sub-cam, a shaft which functions as a rotating shaft of the main cam and the sub-cam, and a spring which connects the main cam and the sub-cam; a permanent magnet which is connected to the shift lock cam part; and an electromagnet arranged to have a polarity arrangement opposite to that of the permanent magnet.

A method for operating a transmission (2) of a motor vehicle includes, in order to trigger a gear shift in the transmission (2), determining a trigger speed depending on a response time of the gear shift to be implemented, depending on a gradient of a motor vehicle-side rotational speed, and depending on a maximum permissible limit speed for the motor vehicle-side rotational speed. The gear shift to be implemented triggered on a control side as function of the trigger speed such that the motor vehicle-side rotational speed does not exceed the maximum permissible limit speed during the implementation of the gear shift. The method also include adapting the trigger speed.

A method for operating a transmission (2) of a motor vehicle includes, in order to trigger a gear shift in the transmission (2), determining a trigger speed depending on a response time of the gear shift to be implemented, depending on a gradient of a motor vehicle-side rotational speed, and depending on a maximum permissible limit speed for the motor vehicle-side rotational speed. The gear shift to be implemented triggered on a control side as function of the trigger speed such that the motor vehicle-side rotational speed does not exceed the maximum permissible limit speed during the implementation of the gear shift. The method also include adapting the trigger speed.

A vehicle controller controls a vehicle including an engine and an automatic transmission. The vehicle controller includes an electronic control unit. The electronic control unit estimates power generable by the engine based on a condition of the engine and a condition of the automatic transmission in a non-driving range, calculates a load on the automatic transmission in a driving range based on a condition of the automatic transmission in the driving range, determines whether a difference between the power and the load is equal to or smaller than a predetermined threshold by which an engine stall is identifiable, and limits a gear shift request from the non-driving range to the driving range when the difference is equal to or smaller than the predetermined threshold.

To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.

This vehicle control device 10 is provided with: a current gear stage selection unit 13 which selects a current gear stage, which is the gear stage of the vehicle in the present travel state; a travel segment determination unit 15 which determines the next travel segment forwards in the direction of travel of the vehicle V; and a shift control unit 17 which, in the case that the current gear stage selection unit 13 has newly selected a target gear stage lower than the current gear stage during travel of the vehicle V in the current gear stage in the current travel segment, if the next travel segment can be traveled in the current gear stage and the amount the vehicle V will lose speed after traveling the current travel segment is less than or equal to a prescribed threshold value, controls shifting of the gear stage such that downshifting from the current gear stage to the target gear stage is suppressed and the current gear stage is maintained. Even in a state in which downshifting is suppressed, if the state of the vehicle the satisfies a prescribed condition, then the shift control unit 17 controls shifting of the gear stage so as to downshift to the target gear stage without suppression of downshifting.

A vehicle controller controls a vehicle including an engine and an automatic transmission. The vehicle controller includes an electronic control unit. The electronic control unit estimates power generable by the engine based on a condition of the engine and a condition of the automatic transmission in a non-driving range, calculates a load on the automatic transmission in a driving range based on a condition of the automatic transmission in the driving range, determines whether a difference between the power and the load is equal to or smaller than a predetermined threshold by which an engine stall is identifiable, and limits a gear shift request from the non-driving range to the driving range when the difference is equal to or smaller than the predetermined threshold.