US Patent 7840329 Automatic transmission, and apparatus and method of controlling the same

An automatic transmission includes at least an input section, an output section, first and second frictional engagement elements, and a controller. The input section receives an input torque from a drive unit. The first frictional engagement element has an engaged state allowing the output section to rotate at a first transmission gear ratio with respect to the input section. The second frictional engagement element has an engaged state allowing the output section to rotate at a second transmission gear ratio with respect to the input section. The controller controls at least a gear shift from the first transmission gear ratio to the second transmission gear ratio. The controller controls the first and second frictional engagement elements and the drive unit so as to cancel an inertia torque resulting from the gear shift.