Motor vehicle having at least two drive motors and having an automatic gearbox that has one fixed and one power-split transmission ratio

Abstract

A motor vehicle has at least two drive motors, at least one drive motor being an electric machine; a high-voltage accumulator; and an automatic gearbox, having at least one fixed transmission ratio and at least one power-split transmission ratio for transmission regulation starting from the at least one fixed transmission ratio. The motor vehicle further includes an electronic control unit, which is designed such that, when a gear change command is present, the shifting element to be opened of the fixed transmission ratio to be disengaged is unloaded in a torque-controlled manner by at least two of the drive motors. For the shifting element to be opened, the torque load is calculated and observed. The torque load is observed with the objective of bringing about a load change by way of a zero crossing in order to produce a no-load state at the shifting element. For producing the no-load state of the shifting element to be opened, a first drive motor and a second drive motor are controlled in a power split manner such that they, in terms of rotational speeds, maintain the transmission of the previously engaged fixed transmission ratio, and, in terms of torque, put the shifting element to be opened in an at least nearly no-load state, and a load change is brought about at the shifting element to be opened by a differential rotational speed, opposite the calculated torque load at the shifting element to be opened, being specified at the shifting element.