A method of controlling an automatic transmission is provided. The automatic transmission includes a piston having first and second surfaces opposite from each other, friction plates, engaging and disengaging hydraulic pressure chambers for supplying and discharging hydraulic pressure and directing the piston to push the friction plates to be engaged and disengaged, a hydraulic pressure control valve for supplying and discharging hydraulic pressure to and from the chambers, first and second oil paths communicating the valve with the chambers, and a pressure reducing valve disposed in the second oil path and for preventing hydraulic pressure of the disengaging hydraulic pressure chamber from exceeding a given set pressure. The second surface has a larger area for receiving hydraulic pressure than an area of the first surface for receiving hydraulic pressure. The method includes changing the given set pressure according to information regarding a state of the automatic transmission.

A recreational vehicle is provided including a power source, such as an engine or an electric motor, and a transmission having a variable gear ratio. A sub-transmission coupled to an output of the transmission includes a plurality of selectable gear configurations including park gear and at least one of a forward gear, a neutral gear and a reverse gear. An electronic controller is operative to electronically control the gear configuration of the sub-transmission in response to a set of conditions.

A travel control device is provided with hydraulic pumps of a variable capacity type that are driven by an engine; hydraulic motors that are driven by discharged oil from the hydraulic pumps; traveling devices that are rotation-driven by the hydraulic motors; a travel operation lever that is operated so as to instruct a traveling operation; a first control valve for generating a charged hydraulic pressure by adjusting the discharged oil from a charge pump and a second control valve for generating a capacity control hydraulic pressure in accordance with the operation of the travel operation lever. The first control valve is designed to pressure-adjust and generate a charged hydraulic pressure in accordance with the rotation speed of the engine, and the hydraulic pump is subjected to a variable capacity control process by a capacity control hydraulic pressure that is pressure-adjusted and generated by the second control valve.

A travel control device is provided with hydraulic pumps of a variable capacity type that are driven by an engine; hydraulic motors that are driven by discharged oil from the hydraulic pumps; traveling devices that are rotation-driven by the hydraulic motors; a travel operation lever that is operated so as to instruct a traveling operation; a first control valve for generating a charged hydraulic pressure by adjusting the discharged oil from a charge pump and a second control valve for generating a capacity control hydraulic pressure in accordance with the operation of the travel operation lever. The first control valve is designed to pressure-adjust and generate a charged hydraulic pressure in accordance with the rotation speed of the engine, and the hydraulic pump is subjected to a variable capacity control process by a capacity control hydraulic pressure that is pressure-adjusted and generated by the second control valve.

Methods and systems are provided for an actuation system for a parking mechanism in a transmission system of a vehicle. In one example, a system may include a protrusion positioned at one end of a higher diameter portion of a cam, the protrusion positioned to contact a pawl upon engagement of the pawl with a parking gear.

A control apparatus for controlling a linear solenoid by controlling a driving current supplied to the linear solenoid through a feedback control. The feedback control is executed by a feedback control system having parameters that are determined in accordance with an ILQ design method. In a frequency characteristic of a gain of a transfer function representing a ratio of an output to a disturbance in the feedback control system, the gain is lower than 0 [dB] throughout all frequency ranges.

An apparatus comprising an interface, a memory and a processor. The interface may be configured to receive sensor data samples during operation of a vehicle. The memory may be configured to store the sensor data samples over a number of points in time. The processor may be configured to analyze the sensor data samples stored in the memory to detect a pattern. The processor may be configured to manage an application of brakes of the vehicle in response to the pattern.

A slip control method and arrangement for a drivetrain including a continuously variable transmission, forward-reverse clutch arrangement and an optional three-speed gearbox is described herein. The forward-reverse clutch arrangement includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling.

A slip control method and arrangement for a drivetrain including a continuously variable transmission, forward-reverse clutch arrangement and an optional three-speed gearbox is described herein. The forward-reverse clutch arrangement includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling.

An apparatus comprising an interface, a memory and a processor. The interface may be configured to receive sensor data samples during operation of a vehicle. The memory may be configured to store the sensor data samples over a number of points in time. The processor may be configured to analyze the sensor data samples stored in the memory to detect a pattern. The processor may be configured to manage an application of brakes of the vehicle in response to the pattern.