A work machine includes an engine, a transmission connected to the engine to change a transmission gear ratio continuously, a travel device connected to the transmission to cause the work machine to travel, a sensor arranged and configured to detect an acceleration of the work machine, and a controller. The controller selectively execute a first mode and a second mode that limits a target tractive force of the machine in comparison to the first mode. The controller weakens limitation of the target tractive force and determines the target tractive force when the acceleration of the machine in the second mode is less than a predetermined acceleration threshold. The controller determines a target transmission gear ratio in accordance with the target tractive force. The controller controls the transmission based on the target transmission gear ratio.

Provided is a wheel loader capable of automatically decreasing vehicle speed without making an operator feel discomfort during a loading operation. A wheel loader 1 mounted with a torque converter type traveling drive system comprises a controller 5 configured to control shifting of a transmission 32. When a vehicle body travels forward at vehicle speed corresponding to a second speed stage set greater by one speed stage than the lowest speed stage of the transmission 32 while operating the lift arm 21 upwardly, the controller 5 sets, as a gear ratio of the transmission 32, an intermediate gear ratio between a gear ratio corresponding to the second speed stage and a gear ratio corresponding to a first speed stage, and outputs a signal for selecting a combination of a plurality of gears corresponding to the set gear ratio to each first to fifth solenoid control valves 32A to 32E.

Provided is a gear change control device of automatic transmission for vehicles. The gear change control device of automatic transmission includes a gear change control part which performs upshift gear change control and downshift gear change control of an automatic transmission according to a shift map. When an operation of a brake operation element is detected and full closure of an accelerator is detected, the gear change control part calculates, based on a change amount of a vehicle speed and a pressure of a brake master cylinder, a determination counter value for determining whether or not to execute the downshift of the automatic transmission, and when the determination counter value is equal to or greater than a threshold value (first threshold value), the gear change control part performs the downshift of the automatic transmission.

A vehicle travel control method and a vehicle travel control device carries out a downshift control of an automatic transmission when a vehicle speed increases from a set vehicle speed during a constant speed travel control by at least a first prescribed value. Subsequent downshift control of the automatic transmission is prohibited upon determining the vehicle speed has increased from the set vehicle speed by at least the first prescribed value due to an operation of an operating element by the driver during constant speed travel control. Downshift control of the automatic transmission is executed upon determining insufficient deceleration of the vehicle exists where the driver is not operating the accelerator pedal during prohibition of the downshift control.

An apparatus for controlling a transmission of a vehicle includes: a determination device that decides whether to perform a forward vehicle-based deceleration tracking control, based on information of the vehicle and a forward vehicle, when the vehicle starts to coast; a calculation device that calculates a target velocity and a target distance based on a position and a velocity of the forward vehicle, when the forward vehicle-based deceleration tracking control is decided to be performed; a gear position decision device that constructs deceleration profiles for respective gears and decides a final gear based on the target velocity and the target distance calculated; and a controller that controls the transmission based on the final gear.

Provided is a transmission control device which can improve drivability in an acceleration section even while taking a reduction of fuel consumption in a deceleration section into consideration. The transmission control device (transmission controller) which controls a transmission in a running control of a vehicle includes a shift timing calculation unit which determines an acceleration position at which the vehicle accelerates on the basis of a target speed pattern generated from external information, a target gear ratio calculation unit which determines a required gear ratio which is required at the acceleration position, and a gear ratio overwriting command unit which outputs a command of overwriting the gear ratio such that the gear ratio at the acceleration position approaches the required gear ratio. In the control of the transmission of the transmission controller, the gear ratio is set to the required gear ratio (target gear ratio) at a predetermined point after the vehicle exits the deceleration section and reaches the acceleration position.

A control system operates a power train of a work vehicle. The system includes a transmission arrangement which transfers power from an engine to an output shaft of the vehicle to drive the vehicle in a first or second direction according to at least one forward or reverse modes. The arrangement includes a forward directional clutch and a reverse directional clutch, and a controller. The controller is configured to determine if one of the clutches is engaged; evaluate a speed of the engine; and provide a torque command to engage the other of the clutches to slow the speed of the engine when a shuttle shift is initiated, or when the speed of the engine exceeds a predetermined speed threshold.

Provided is a transmission control device which can improve drivability in an acceleration section even while taking a reduction of fuel consumption in a deceleration section into consideration. The transmission control device (transmission controller) which controls a transmission in a running control of a vehicle includes a shift timing calculation unit which determines an acceleration position at which the vehicle accelerates on the basis of a target speed pattern generated from external information, a target gear ratio calculation unit which determines a required gear ratio which is required at the acceleration position, and a gear ratio overwriting command unit which outputs a command of overwriting the gear ratio such that the gear ratio at the acceleration position approaches the required gear ratio. In the control of the transmission of the transmission controller, the gear ratio is set to the required gear ratio (target gear ratio) at a predetermined point after the vehicle exits the deceleration section and reaches the acceleration position.

A method and an apparatus for controlling driving power from a powertrain of a motor vehicle comprising a kickdown switch, wherein an activation of the kickdown switch triggers a default action of temporarily requesting an increase of a maximum power available from the powertrain, the method comprising: recognizing that a speed limiter, setting an upper speed limit for the vehicle speed, is active, comparing a current vehicle speed to a predefined speed threshold, which is below the upper speed limit, and if the current vehicle speed is above the speed threshold and the speed limiter is active, triggering an altered action in response to the activation of the kickdown switch.

A method and an apparatus for controlling driving power from a powertrain of a motor vehicle comprising a kickdown switch, wherein an activation of the kickdown switch triggers a default action of temporarily requesting an increase of a maximum power available from the powertrain, the method comprising: recognizing that a speed limiter, setting an upper speed limit for the vehicle speed, is active, comparing a current vehicle speed to a predefined speed threshold, which is below the upper speed limit, and if the current vehicle speed is above the speed threshold and the speed limiter is active, triggering an altered action in response to the activation of the kickdown switch.