An oil pressure estimation device for calculating an estimated differential pressure that is an estimated value of a differential pressure between two oil chambers generated in a torque converter including the two oil chambers and a lockup clutch includes a storage device and an execution device. The storage device stores mapping data defining a mapping, the mapping outputting as an output variable an estimated differential pressure variable indicating the estimated differential pressure, in response to input of an input variable, and the mapping having been trained by machine learning. The mapping includes an instruction differential pressure variable indicating the instruction differential pressure as one of a plurality of the input variables. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable into the mapping to calculate a value of the output variable.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

A hydraulic pressure control method for a vehicle transmission includes accumulating factors representing vehicle usage, accumulating factors representing driver's driving tendency, calculating a first line pressure compensation value according to the usage depending on the accumulated values of the factors representing the vehicle usage, calculating a second line pressure compensation value according to the driver's driving tendency depending on the accumulated values of the factors representing the driver's driving tendency, determining a final line pressure by adding the first and second line pressure compensation values according to the usage and the driver's driving tendency to a basic line pressure, and operating a transmission hydraulic system according to the final line pressure.

A hydrostatic traction drive has a steering function, which is implemented via two laterally acting secondary units (traction motors), which are supplied by a common primary unit (pump) in the open circuit. The primary unit is pressure-controlled. The two secondary units are torque-controlled. The affected vehicle is steerable as a function of a steering command by different torque specifications for the two secondary units. Furthermore, a hydrostatic drive for a mobile work machine has working hydraulics in addition to the traction drive. The working hydraulics are also supplied by the primary unit in parallel to the two secondary units.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

A hydraulic pressure calculation apparatus is applied to a gear shifting system including a transmission configured to switch between a connected state and a disconnected state of a friction engagement element depending on a hydraulic pressure supplied from a hydraulic circuit, and a hydraulic controller configured to control the hydraulic circuit. The hydraulic pressure calculation apparatus includes a memory and a processor. The memory stores pieces of mapping data of a plurality of phases obtained by dividing a period from a start to an end of switching between the connected state and the disconnected state of the friction engagement element. Each piece of the mapping data defines a mapping. The processor is configured to output, as an output variable, an estimated hydraulic pressure variable indicating an estimated value of an actual hydraulic pressure supplied from the hydraulic circuit to the friction engagement element.

A shift device includes: a shift switching member including valley parts corresponding to a shift position; a positioning member provided to establish the shift position in a state of being fitted into any one of the valley parts; a motor including a rotor and a stator and driving the shift switching member; a speed reduction mechanism section rotating the shift switching member in a state in which a rotation speed transmitted from the motor is reduced; a rotor rotational angle sensor detecting a rotational angle of the rotor; and an output shaft rotational angle sensor detecting a rotational angle of the shift switching member. The shift device detects the number of rotations of the motor based on association between output values of the output shaft rotational angle sensor and the rotor rotational angle sensor.

A nonlinear closed-loop control combined with an integral time-delay feedback control is disclosed to adjust a speed ratio of an infinitely variable transmission (IVT) system. A speed ratio control for an IVT system involves a forward speed controller and a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.

A method for controlling an electric oil pump (EOP) of a torque assist automated manual transmission (AMT) using a multi-plate wet clutch and a dry clutch, may include correcting an EOP operating line on a shifting pattern graph such that the EOP operates prior to up-shifting from a first gear to a second gear while driving in the first gear.

A vehicle control device includes a processor and memory. The memory stores relation-defining data for defining a relation between a state of a vehicle and an action variable that is a variable relating to operations of a transmission installed in the vehicle. The processor is configured to execute acquisition processing, operation processing, reward calculation processing, updating processing, counting processing, and limiting processing. The processor is configured to output the relation-defining data updated so that an expected income is increased when the transmission is operated following the relation-defining data, based on an updating map.